- stunnel-users - stunnel.org

CERT: Subject checks failed
by wkwok＠crestron.com 25 Jul '22

25 Jul '22

I'm new to stunnel and think it may be easier to use this in our environment. Any help would be appreciated! Here is my setup. Source and Destination OS: Windows 2022 Data Center VMs I copied the stunnel.pem from SERVER to CLIENT and named it stunnel_client.pem. I get the following error when connecting from CLIENT -> SERVER. 2022.07.23 17:30:28 LOG6[3]: SNI: sending servername: x.x.x.x 2022.07.23 17:30:28 LOG6[3]: Peer certificate required 2022.07.23 17:30:28 LOG4[3]: CERT: Subject checks failed 2022.07.23 17:30:28 LOG4[3]: Rejected by CERT at depth=0: C=US, ST=New Jersey, L=Edison, O=Crestron, OU=ProPortal, CN=vmsql-edatahub-.crestron.com 2022.07.23 17:30:28 LOG3[3]: SSL_connect: ssl/statem/statem_clnt.c:1887: error:0A000086:SSL routines::certificate verify failed 2022.07.23 17:30:28 LOG5[3]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket *****STUNNEL.CONF***** SERVER: socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 socket = l:SO_KEEPALIVE=1 socket = r:SO_KEEPALIVE=1 options = NO_SSLv2 options = NO_SSLv3 options = NO_TLSv1 sslVersion = TLSv1.2 [ncatListener] accept = 8443 connect = 4489 cert = stunnel.pem CLIENT: socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 socket = l:SO_KEEPALIVE=1 socket = r:SO_KEEPALIVE=1 options = NO_SSLv2 options = NO_SSLv3 options = NO_TLSv1 sslVersion = TLSv1.2 [ncatSender] client = yes accept = 127.0.0.1:4488 connect = <x.x.x.x>:8443 verifyPeer = yes CAfile = stunnel_client.pem checkIP = <x.x.x.x> OCSPaia = yes

2 2

stunnel 5.65 released
by Michał Trojnara 22 Jul '22

22 Jul '22

Dear Users, I have released version 5.65 of stunnel. On Windows, this release fixes a high severity OpenSSL vulnerability: https://www.openssl.org/news/secadv/20220705.txt ### Version 5.65, 2022.07.17, urgency: HIGH * Security bugfixes - OpenSSL DLLs updated to version 3.0.5. * Bugfixes - Fixed handling globally enabled FIPS. - Fixed openssl.cnf processing in WIN32 GUI. - Fixed a number of compiler warnings. - Fixed tests on older versions of OpenSSL. Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: 60c500063bd1feff2877f5726e38278c086f96c178f03f09d264a2012d6bf7fc stunnel-5.65.tar.gz ca88e65888102f7526cab4edad7b30e8d1e82d428c34d5b5f00513dff9ed2288 stunnel-5.65-win64-installer.exe 9dadaa8622e1c1955728cbd8d49e1a6b5eae77bfa5340f7a1f82451121aee740 stunnel-5.65-android.zip Best regards, Mike

2 2

Using stunnel with Outlook for Mac 2011
by glow＠mrbike.com 14 Jul '22

14 Jul '22

I wonder if I can use stunnel to keep using Outlook for Mac 2011. I have Outlook running on a Macbook with Mac OS 10.9.5 (the latest version possible). I can use Outlook in this way because my ISP currently supports TLS 1.0--but that support will soon end, when my ISP migrates its mail servers to TLS 1.2. At that point, my Macbook no longer use Outlook or any similar e-mail client. Is it possible for me to use stunnel so that my Macbook's old Outlook client will work with TLS 1.2?

1 0

stunnel with Winxp
by russell.jim＠rogers.com 13 Jul '22

13 Jul '22

i've used stunnel (v5.35) for many years, always working great. my 3rd party app running on WinXP computer was always able to send emails to gmail account. last month my app on this machine failed to send emails. changing to another (non-gmail) email account did not help. i am assuming issue is something to do with tls 1.0/1.1 on Winxp machine? do i need to do something to get this WinXP app to be able to send emails (outgoing only) again? thanks so much for any advice. /jim

1 0

Memory usage in stunnel-5.63
by roie rachamim 28 Jun '22

28 Jun '22

Hi, I'm running stunnel 5.63 compiled in debian-bullseye inside docker, and i'm trying to understand the allocated memory behavior In a test i'm conducting i'm creating a load towards the stunnel server And the process CPU + memory consumption rises. Once i stop the traffic the CPU goes down but the memory doesn't. Is this expected ? Many Thanks, Roie

2 1

Stunnel's Windows client stopped working in Iran
by landateta＠yahoo.com 26 Jun '22

26 Jun '22

I have a Stunnel server that users connect to from Iran, to circumvent internet censorship. It was working for years but in recent days Stunnel's Windows client has stopped working (maybe due to censorship), but the Android clients like (SSLSocks and SSL Encryptor) do work. So do you have any idea what would be the difference between Windows and Android clients which can help me fix the problem? Any help appreciated.

1 0

Stunnel5.64 Failed to initialize TLS on Windows 7
by White Louis 23 Jun '22

23 Jun '22

Hi All I upgraded Stunnel 5.64, but it got an error about "Failed to initialize TLS." But It works on Windows10/Windows server 2012 with the Stunnel 5.64 and the same configuration Note: The same configuration works with Stunnel5.63 and earlier version on Windows 7. Below is my configuration sslVersion = TLSv1.2 ciphers=HIGH options = NO_SSLv3 [HOST] client = yes accept = 127.0.0.1:59379 connect = remoteIP:Port verify = 3 CAfile = xxx.crt Logs are below: [ ] Initializing inetd mode configuration [ ] Running on Windows 6.1 [ ] No limit detected for the number of clients [.] stunnel 5.64 on x64-pc-mingw32-gnu platform [.] Compiled/running with OpenSSL 3.0.3 3 May 2022 [.] Threading:WIN32 Sockets:SELECT,IPv6 TLS:ENGINE,OCSP,PSK,SNI [ ] errno: (*_errno()) [ ] Initializing inetd mode configuration [ ] Running on Windows 6.1 [.] Reading configuration from file C:\Users\vm\AppData\Local\Temp\0660770671653983902255\stunnel.conf [.] UTF-8 byte order mark not detected [.] FIPS mode disabled [ ] Compression enabled: 0 methods [!] PRNG seeded with 0 bytes total [!] PRNG was not seeded with enough random bytes [!] Global options: Failed to initialize TLS [!] Configuration failed [ ] Deallocating temporary section defaults Server is down

1 0

Connection to Outlook O365 owa
by raduci＠gmail.com 09 Jun '22

09 Jun '22

Dear all, I am trying to connect via stunnel to O365 OWA. Configuration file is below: ; Sample stunnel configuration file for Win64 by Michal Trojnara 2002-2022 ; Some options used here may be inadequate for your particular configuration ; This sample file does *not* represent stunnel.conf defaults ; Please consult the manual for detailed description of available options ; ************************************************************************** ; * Global options * ; ************************************************************************** ; Debugging stuff (may be useful for troubleshooting) debug = 7 output = stunnel.log ; Enable FIPS 140-2 mode if needed for compliance ;fips = yes ; Microsoft CryptoAPI engine allows for authentication with private keys ; stored in the Windows certificate store ; Each section using this feature also needs the "engineId = capi" option engine = capi ; You also need to disable TLS 1.2 or later, because the CryptoAPI engine ; currently does not support PSS ;sslVersionMax = TLSv1.1 ; TLSv1.1 requires security level 0 when compiled OpenSSL 3.0 and later securityLevel = 0 ; The pkcs11 engine allows for authentication with cryptographic ; keys isolated in a hardware or software token ; MODULE_PATH specifies the path to the pkcs11 module shared library, ; such as softhsm2-x64.dll or opensc-pkcs11.dll ; IMPORTANT: A 64-bit stunnel requires 64-bit PKCS#11 modules ; Each section using this feature also needs the "engineId = pkcs11" option ;engine = pkcs11 ;engineCtrl = MODULE_PATH:softhsm2-x64.dll ;engineCtrl = PIN:1234 ; ************************************************************************** ; * Service defaults may also be specified in individual service sections * ; ************************************************************************** ; Enable support for the insecure SSLv3 protocol ;options = -NO_SSLv3 ; These options provide additional security at some performance degradation ;options = SINGLE_ECDH_USE ;options = SINGLE_DH_USE ; ************************************************************************** ; * Include all configuration file fragments from the specified folder * ; ************************************************************************** ;include = conf.d ; ************************************************************************** ; * Service definitions (at least one service has to be defined) * ; ************************************************************************** ; ***************************************** Example TLS client mode services ; Encrypted HTTP proxy authenticated with a client certificate ; located in the Windows certificate store [O365] client = yes accept = 192.168.0.225:443 connect = outlook.office.com:443 engineId = capi ; Encrypted HTTP proxy authenticated with a client certificate ; located in a cryptographic token ;[example-pkcs11] ;client = yes ;accept = 127.0.0.1:8080 ;connect = example.com:8443 ;engineId = pkcs11 ;cert = pkcs11:token=MyToken;object=MyCert ;key = pkcs11:token=MyToken;object=MyKey ; ***************************************** Example TLS server mode services ;[pop3s] ;accept = 995 ;connect = 110 ;cert = stunnel.pem ;[imaps] ;accept = 993 ;connect = 143 ;cert = stunnel.pem ; Either only expose this service to trusted networks, or require ; authentication when relaying emails originated from loopback. ; Otherwise the following configuration creates an open relay. ;[ssmtp] ;accept = 465 ;connect = 25 ;cert = stunnel.pem ; TLS front-end to a web server ;[https] ;accept = 443 ;connect = 80 ;cert = stunnel.pem ; "TIMEOUTclose = 0" is a workaround for a design flaw in Microsoft SChannel ; Microsoft implementations do not use TLS close-notify alert and thus they ; are vulnerable to truncation attacks ;TIMEOUTclose = 0 ; Remote cmd.exe protected with PSK-authenticated TLS ; Create "secrets.txt" containing IDENTITY:KEY pairs ;[cmd] ;accept = 1337 ;exec = c:\windows\system32\cmd.exe ;execArgs = cmd.exe ;PSKsecrets = secrets.txt ; vim:ft=dosini In the browser (Firefox) I get the below error: Secure Connection Failed An error occurred during a connection to 192.168.0.225. SSL received a record that exceeded the maximum permissible length. Error code: SSL_ERROR_RX_RECORD_TOO_LONG The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem. Chrome says: 192.168.0.225 sent an invalid response. Try running Windows Network Diagnostics. ERR_SSL_PROTOCOL_ERROR Logs are below: Found 1 ready file descriptor(s) 2022.06.09 15:46:32 LOG7[main]: FD=604 ifds=r-x ofds=r-- 2022.06.09 15:46:32 LOG7[main]: FD=908 ifds=r-x ofds=--- 2022.06.09 15:46:32 LOG7[main]: Dispatching a signal from the signal pipe 2022.06.09 15:46:32 LOG7[main]: Processing SIGNAL_RELOAD_CONFIG 2022.06.09 15:46:33 LOG6[main]: Initializing inetd mode configuration 2022.06.09 15:46:33 LOG7[main]: Running on Windows 6.2 2022.06.09 15:46:33 LOG5[main]: Reading configuration from file C:\Program Files (x86)\stunnel\config\stunnel.conf 2022.06.09 15:46:33 LOG5[main]: UTF-8 byte order mark detected 2022.06.09 15:46:33 LOG7[main]: Enabling support for engine "capi" 2022.06.09 15:46:33 LOG6[main]: UI not supported by engine #1 (capi) 2022.06.09 15:46:33 LOG7[main]: Initializing engine #1 (capi) 2022.06.09 15:46:33 LOG6[main]: Engine #1 (capi) initialized 2022.06.09 15:46:33 LOG5[main]: FIPS mode disabled 2022.06.09 15:46:33 LOG6[main]: Compression enabled: 0 methods 2022.06.09 15:46:33 LOG7[main]: No PRNG seeding was required 2022.06.09 15:46:33 LOG6[main]: Initializing service [O365] 2022.06.09 15:46:33 LOG6[main]: User-specified security level set: 0 2022.06.09 15:46:33 LOG7[main]: Ciphers: HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK 2022.06.09 15:46:33 LOG7[main]: TLSv1.3 ciphersuites: TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256 2022.06.09 15:46:33 LOG7[main]: TLS options: 0x2100000 (+0x0, -0x0) 2022.06.09 15:46:33 LOG6[main]: Session resumption enabled 2022.06.09 15:46:33 LOG6[main]: Client certificate engine (capi) enabled 2022.06.09 15:46:33 LOG7[main]: No certificate or private key specified 2022.06.09 15:46:33 LOG4[main]: Service [O365] needs authentication to prevent MITM attacks 2022.06.09 15:46:33 LOG6[main]: DH initialization skipped: client section 2022.06.09 15:46:33 LOG7[main]: ECDH initialization 2022.06.09 15:46:33 LOG7[main]: ECDH initialized with curves X25519:P-256:X448:P-521:P-384 2022.06.09 15:46:33 LOG5[main]: Configuration successful 2022.06.09 15:46:33 LOG7[main]: Unbinding service [O365] 2022.06.09 15:46:33 LOG7[main]: Service [O365] closed (FD=908) 2022.06.09 15:46:33 LOG7[main]: Service [O365] closed 2022.06.09 15:46:33 LOG7[main]: Deallocating deployed section defaults 2022.06.09 15:46:33 LOG7[main]: Deallocating section [O365] 2022.06.09 15:46:33 LOG5[main]: Logging to C:\Users\radc\AppData\Local\stunnel.log 2022.06.09 15:46:33 LOG7[main]: Binding service [O365] 2022.06.09 15:46:33 LOG7[main]: Listening file descriptor created (FD=1580) 2022.06.09 15:46:33 LOG7[main]: Setting accept socket options (FD=1580) 2022.06.09 15:46:33 LOG7[main]: Option SO_EXCLUSIVEADDRUSE set on accept socket 2022.06.09 15:46:33 LOG6[main]: Service [O365] (FD=1580) bound to 192.168.0.225:443 2022.06.09 15:47:19 LOG7[17]: Service [O365] started 2022.06.09 15:47:19 LOG7[17]: Setting local socket options (FD=1624) 2022.06.09 15:47:19 LOG7[main]: FD=604 ifds=r-x ofds=--- 2022.06.09 15:47:19 LOG7[17]: Option TCP_NODELAY set on local socket 2022.06.09 15:47:19 LOG5[17]: Service [O365] accepted connection from 192.168.0.200:55381 2022.06.09 15:47:19 LOG7[main]: FD=1580 ifds=r-x ofds=r-- 2022.06.09 15:47:19 LOG6[17]: failover: priority, starting at entry #0 2022.06.09 15:47:19 LOG7[main]: Service [O365] accepted (FD=1608) from 192.168.0.200:55382 2022.06.09 15:47:19 LOG6[17]: s_connect: connecting 52.98.152.162:443 2022.06.09 15:47:19 LOG7[main]: Creating a new thread 2022.06.09 15:47:19 LOG7[main]: New thread created 2022.06.09 15:47:19 LOG7[18]: Service [O365] started 2022.06.09 15:47:19 LOG7[18]: Setting local socket options (FD=1608) 2022.06.09 15:47:19 LOG7[18]: Option TCP_NODELAY set on local socket 2022.06.09 15:47:19 LOG5[18]: Service [O365] accepted connection from 192.168.0.200:55382 2022.06.09 15:47:19 LOG6[18]: failover: priority, starting at entry #0 2022.06.09 15:47:19 LOG6[18]: s_connect: connecting 52.98.152.162:443 2022.06.09 15:47:19 LOG7[17]: s_connect: s_poll_wait 52.98.152.162:443: waiting 10 seconds 2022.06.09 15:47:19 LOG7[17]: FD=1596 ifds=rwx ofds=--- 2022.06.09 15:47:19 LOG7[18]: s_connect: s_poll_wait 52.98.152.162:443: waiting 10 seconds 2022.06.09 15:47:19 LOG7[18]: FD=1204 ifds=rwx ofds=--- 2022.06.09 15:47:19 LOG5[17]: s_connect: connected 52.98.152.162:443 2022.06.09 15:47:19 LOG5[17]: Service [O365] connected remote server from 10.57.2.17:57847 2022.06.09 15:47:19 LOG7[17]: Setting remote socket options (FD=1596) 2022.06.09 15:47:19 LOG7[17]: Option TCP_NODELAY set on remote socket 2022.06.09 15:47:19 LOG7[17]: Remote descriptor (FD=1596) initialized 2022.06.09 15:47:19 LOG6[17]: SNI: sending servername: outlook.office.com 2022.06.09 15:47:19 LOG6[17]: Peer certificate not required 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): before SSL initialization 2022.06.09 15:47:19 LOG7[17]: Initializing application specific data for session authenticated 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG5[18]: s_connect: connected 52.98.152.162:443 2022.06.09 15:47:19 LOG5[18]: Service [O365] connected remote server from 10.57.2.17:57848 2022.06.09 15:47:19 LOG7[18]: Setting remote socket options (FD=1204) 2022.06.09 15:47:19 LOG7[18]: Option TCP_NODELAY set on remote socket 2022.06.09 15:47:19 LOG7[18]: Remote descriptor (FD=1204) initialized 2022.06.09 15:47:19 LOG6[18]: SNI: sending servername: outlook.office.com 2022.06.09 15:47:19 LOG6[18]: Peer certificate not required 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): before SSL initialization 2022.06.09 15:47:19 LOG7[18]: Initializing application specific data for session authenticated 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS write change cipher spec 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS write change cipher spec 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): TLSv1.3 read encrypted extensions 2022.06.09 15:47:19 LOG6[17]: Certificate verification disabled 2022.06.09 15:47:19 LOG6[17]: Certificate verification disabled 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS read server certificate 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): TLSv1.3 read server certificate verify 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS read finished 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:19 LOG7[17]: TLS state (connect): SSLv3/TLS write finished 2022.06.09 15:47:19 LOG7[17]: 2 client connect(s) requested 2022.06.09 15:47:19 LOG7[17]: 1 client connect(s) succeeded 2022.06.09 15:47:19 LOG7[17]: 0 client renegotiation(s) requested 2022.06.09 15:47:19 LOG7[17]: 0 session reuse(s) 2022.06.09 15:47:19 LOG6[17]: TLS connected: new session negotiated 2022.06.09 15:47:19 LOG6[17]: TLSv1.3 ciphersuite: TLS_AES_256_GCM_SHA384 (256-bit encryption) 2022.06.09 15:47:19 LOG6[17]: Peer temporary key: ECDH, P-384, 384 bits 2022.06.09 15:47:19 LOG7[17]: Compression: null, expansion: null 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): TLSv1.3 read encrypted extensions 2022.06.09 15:47:19 LOG6[18]: Certificate verification disabled 2022.06.09 15:47:19 LOG6[18]: Certificate verification disabled 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS read server certificate 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): TLSv1.3 read server certificate verify 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS read finished 2022.06.09 15:47:19 LOG7[18]: TLS state (connect): SSLv3/TLS write finished 2022.06.09 15:47:19 LOG7[18]: 2 client connect(s) requested 2022.06.09 15:47:19 LOG7[18]: 2 client connect(s) succeeded 2022.06.09 15:47:19 LOG7[18]: 0 client renegotiation(s) requested 2022.06.09 15:47:19 LOG7[18]: 0 session reuse(s) 2022.06.09 15:47:19 LOG6[18]: TLS connected: new session negotiated 2022.06.09 15:47:19 LOG6[18]: TLSv1.3 ciphersuite: TLS_AES_256_GCM_SHA384 (256-bit encryption) 2022.06.09 15:47:19 LOG6[18]: Peer temporary key: ECDH, P-384, 384 bits 2022.06.09 15:47:19 LOG7[18]: Compression: null, expansion: null 2022.06.09 15:47:20 LOG7[17]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[17]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[17]: Initializing application specific data for session authenticated 2022.06.09 15:47:20 LOG7[17]: Deallocating application specific data for session connect address 2022.06.09 15:47:20 LOG7[17]: New session callback 2022.06.09 15:47:20 LOG7[17]: Peer certificate was cached (4822 bytes) 2022.06.09 15:47:20 LOG6[17]: Session id: 8C30BA078B16527A627B472B16BD94469EF8EF2C2B3DC4DE83C9E9DD0454AE89 2022.06.09 15:47:20 LOG7[17]: TLS state (connect): SSLv3/TLS read server session ticket 2022.06.09 15:47:20 LOG7[17]: Remove session callback 2022.06.09 15:47:20 LOG7[17]: TLS alert (write): fatal: decode error 2022.06.09 15:47:20 LOG3[17]: SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading 2022.06.09 15:47:20 LOG5[17]: Connection reset: 517 byte(s) sent to TLS, 505 byte(s) sent to socket 2022.06.09 15:47:20 LOG7[17]: Remote descriptor (FD=1596) closed 2022.06.09 15:47:20 LOG7[17]: Local descriptor (FD=1624) closed 2022.06.09 15:47:20 LOG7[17]: Service [O365] finished (1 left) 2022.06.09 15:47:20 LOG7[main]: Found 1 ready file descriptor(s) 2022.06.09 15:47:20 LOG7[main]: FD=604 ifds=r-x ofds=--- 2022.06.09 15:47:20 LOG7[main]: FD=1580 ifds=r-x ofds=r-- 2022.06.09 15:47:20 LOG7[main]: Service [O365] accepted (FD=1132) from 192.168.0.200:55383 2022.06.09 15:47:20 LOG7[main]: Creating a new thread 2022.06.09 15:47:20 LOG7[main]: New thread created 2022.06.09 15:47:20 LOG7[19]: Service [O365] started 2022.06.09 15:47:20 LOG7[19]: Setting local socket options (FD=1132) 2022.06.09 15:47:20 LOG7[19]: Option TCP_NODELAY set on local socket 2022.06.09 15:47:20 LOG5[19]: Service [O365] accepted connection from 192.168.0.200:55383 2022.06.09 15:47:20 LOG6[19]: failover: priority, starting at entry #0 2022.06.09 15:47:20 LOG6[19]: s_connect: connecting 52.98.152.162:443 2022.06.09 15:47:20 LOG7[19]: s_connect: s_poll_wait 52.98.152.162:443: waiting 10 seconds 2022.06.09 15:47:20 LOG7[19]: FD=848 ifds=rwx ofds=--- 2022.06.09 15:47:20 LOG7[18]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[18]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[18]: Initializing application specific data for session authenticated 2022.06.09 15:47:20 LOG7[18]: Deallocating application specific data for session connect address 2022.06.09 15:47:20 LOG7[18]: New session callback 2022.06.09 15:47:20 LOG7[18]: Deallocating application specific data for session connect address 2022.06.09 15:47:20 LOG6[18]: Session id: 052BDBEAEF57DAF30820ADD1223A0C800EC7C7FBEFC8D6ECAAA50A67383A26F8 2022.06.09 15:47:20 LOG7[18]: TLS state (connect): SSLv3/TLS read server session ticket 2022.06.09 15:47:20 LOG7[18]: Remove session callback 2022.06.09 15:47:20 LOG7[18]: TLS alert (write): fatal: decode error 2022.06.09 15:47:20 LOG3[18]: SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading 2022.06.09 15:47:20 LOG5[18]: Connection reset: 517 byte(s) sent to TLS, 505 byte(s) sent to socket 2022.06.09 15:47:20 LOG7[18]: Remote descriptor (FD=1204) closed 2022.06.09 15:47:20 LOG7[18]: Local descriptor (FD=1608) closed 2022.06.09 15:47:20 LOG7[18]: Service [O365] finished (1 left) 2022.06.09 15:47:20 LOG7[main]: Found 1 ready file descriptor(s) 2022.06.09 15:47:20 LOG7[main]: FD=604 ifds=r-x ofds=--- 2022.06.09 15:47:20 LOG7[main]: FD=1580 ifds=r-x ofds=r-- 2022.06.09 15:47:20 LOG7[main]: Service [O365] accepted (FD=844) from 192.168.0.200:55384 2022.06.09 15:47:20 LOG7[main]: Creating a new thread 2022.06.09 15:47:20 LOG7[main]: New thread created 2022.06.09 15:47:20 LOG7[20]: Service [O365] started 2022.06.09 15:47:20 LOG7[20]: Setting local socket options (FD=844) 2022.06.09 15:47:20 LOG7[20]: Option TCP_NODELAY set on local socket 2022.06.09 15:47:20 LOG5[20]: Service [O365] accepted connection from 192.168.0.200:55384 2022.06.09 15:47:20 LOG6[20]: failover: priority, starting at entry #0 2022.06.09 15:47:20 LOG6[20]: s_connect: connecting 52.98.152.162:443 2022.06.09 15:47:20 LOG7[20]: s_connect: s_poll_wait 52.98.152.162:443: waiting 10 seconds 2022.06.09 15:47:20 LOG7[20]: FD=1120 ifds=rwx ofds=--- 2022.06.09 15:47:20 LOG5[19]: s_connect: connected 52.98.152.162:443 2022.06.09 15:47:20 LOG5[19]: Service [O365] connected remote server from 10.57.2.17:57849 2022.06.09 15:47:20 LOG7[19]: Setting remote socket options (FD=848) 2022.06.09 15:47:20 LOG7[19]: Option TCP_NODELAY set on remote socket 2022.06.09 15:47:20 LOG7[19]: Remote descriptor (FD=848) initialized 2022.06.09 15:47:20 LOG6[19]: SNI: sending servername: outlook.office.com 2022.06.09 15:47:20 LOG6[19]: Peer certificate not required 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): before SSL initialization 2022.06.09 15:47:20 LOG7[19]: Initializing application specific data for session authenticated 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG5[20]: s_connect: connected 52.98.152.162:443 2022.06.09 15:47:20 LOG5[20]: Service [O365] connected remote server from 10.57.2.17:57850 2022.06.09 15:47:20 LOG7[20]: Setting remote socket options (FD=1120) 2022.06.09 15:47:20 LOG7[20]: Option TCP_NODELAY set on remote socket 2022.06.09 15:47:20 LOG7[20]: Remote descriptor (FD=1120) initialized 2022.06.09 15:47:20 LOG6[20]: SNI: sending servername: outlook.office.com 2022.06.09 15:47:20 LOG6[20]: Peer certificate not required 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): before SSL initialization 2022.06.09 15:47:20 LOG7[20]: Initializing application specific data for session authenticated 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS write change cipher spec 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS write change cipher spec 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS write client hello 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): TLSv1.3 read encrypted extensions 2022.06.09 15:47:20 LOG6[19]: Certificate verification disabled 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS read server hello 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): TLSv1.3 read encrypted extensions 2022.06.09 15:47:20 LOG6[19]: Certificate verification disabled 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS read server certificate 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): TLSv1.3 read server certificate verify 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS read finished 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS write finished 2022.06.09 15:47:20 LOG7[19]: 4 client connect(s) requested 2022.06.09 15:47:20 LOG7[19]: 3 client connect(s) succeeded 2022.06.09 15:47:20 LOG7[19]: 0 client renegotiation(s) requested 2022.06.09 15:47:20 LOG7[19]: 0 session reuse(s) 2022.06.09 15:47:20 LOG6[19]: TLS connected: new session negotiated 2022.06.09 15:47:20 LOG6[19]: TLSv1.3 ciphersuite: TLS_AES_256_GCM_SHA384 (256-bit encryption) 2022.06.09 15:47:20 LOG6[19]: Peer temporary key: ECDH, P-384, 384 bits 2022.06.09 15:47:20 LOG7[19]: Compression: null, expansion: null 2022.06.09 15:47:20 LOG6[20]: Certificate verification disabled 2022.06.09 15:47:20 LOG6[20]: Certificate verification disabled 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS read server certificate 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): TLSv1.3 read server certificate verify 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS read finished 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS write finished 2022.06.09 15:47:20 LOG7[20]: 4 client connect(s) requested 2022.06.09 15:47:20 LOG7[20]: 4 client connect(s) succeeded 2022.06.09 15:47:20 LOG7[20]: 0 client renegotiation(s) requested 2022.06.09 15:47:20 LOG7[20]: 0 session reuse(s) 2022.06.09 15:47:20 LOG6[20]: TLS connected: new session negotiated 2022.06.09 15:47:20 LOG6[20]: TLSv1.3 ciphersuite: TLS_AES_256_GCM_SHA384 (256-bit encryption) 2022.06.09 15:47:20 LOG6[20]: Peer temporary key: ECDH, P-384, 384 bits 2022.06.09 15:47:20 LOG7[20]: Compression: null, expansion: null 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[19]: Initializing application specific data for session authenticated 2022.06.09 15:47:20 LOG7[19]: Deallocating application specific data for session connect address 2022.06.09 15:47:20 LOG7[19]: New session callback 2022.06.09 15:47:20 LOG7[19]: Deallocating application specific data for session connect address 2022.06.09 15:47:20 LOG6[19]: Session id: 3E857D78696F2321EDEE2F622CDB1A050B70B915FB7A6DD37C5DE86EC311534F 2022.06.09 15:47:20 LOG7[19]: TLS state (connect): SSLv3/TLS read server session ticket 2022.06.09 15:47:20 LOG7[19]: Remove session callback 2022.06.09 15:47:20 LOG7[19]: TLS alert (write): fatal: decode error 2022.06.09 15:47:20 LOG3[19]: SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading 2022.06.09 15:47:20 LOG5[19]: Connection reset: 517 byte(s) sent to TLS, 505 byte(s) sent to socket 2022.06.09 15:47:20 LOG7[19]: Remote descriptor (FD=848) closed 2022.06.09 15:47:20 LOG7[19]: Local descriptor (FD=1132) closed 2022.06.09 15:47:20 LOG7[19]: Service [O365] finished (1 left) 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSL negotiation finished successfully 2022.06.09 15:47:20 LOG7[20]: Initializing application specific data for session authenticated 2022.06.09 15:47:20 LOG7[20]: Deallocating application specific data for session connect address 2022.06.09 15:47:20 LOG7[20]: New session callback 2022.06.09 15:47:20 LOG7[20]: Deallocating application specific data for session connect address 2022.06.09 15:47:20 LOG6[20]: Session id: E65F2E71C3EF8E156FA8FAEB5AD445887573D80ED9889F65524514A6ABC02D99 2022.06.09 15:47:20 LOG7[20]: TLS state (connect): SSLv3/TLS read server session ticket 2022.06.09 15:47:20 LOG7[20]: Remove session callback 2022.06.09 15:47:20 LOG7[20]: TLS alert (write): fatal: decode error 2022.06.09 15:47:20 LOG3[20]: SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading 2022.06.09 15:47:20 LOG5[20]: Connection reset: 517 byte(s) sent to TLS, 505 byte(s) sent to socket 2022.06.09 15:47:20 LOG7[20]: Remote descriptor (FD=1120) closed 2022.06.09 15:47:20 LOG7[20]: Local descriptor (FD=844) closed 2022.06.09 15:47:20 LOG7[20]: Service [O365] finished (0 left) Do you have any ideas?

2 1

stunnel started to core dump
by itdo＠cndag.onmicrosoft.com 08 Jun '22

08 Jun '22

Hello all About half a year ago, we started using stunnel on Solaris to secure NFS. The latest available pkg was 5.59 at that time. After a couple of months, stunnel started to core dump on several systems. We updated to the then latest version 5.63. It took again some time until core dumps occurred with 5.63 (still same stack traces). I am aware, that in the meantime 5.64 is out. We are in the process of updating it but it will take some time. Could you please have a look at the below mdb output and tell me if you need any further information to find the root cause? # mdb core.stunnel.339.60001 Loading modules: [ libc.so.1 ld.so.1 ] > ::status debugging core file of stunnel (32-bit) from xxxxxxx file: /opt/csw/bin/stunnel initial argv: /opt/csw/bin/stunnel /etc/opt/csw/stunnel/stunnel.conf start threading model: multi-threaded status: process terminated by SIGSEGV (Segmentation Fault) > $c libssl.so.1.0.0`freelist_extract+0x57(0, 2000000, 14, 42e4db16, 9bd6f8a0, eaf57a5d) > $q In the other dumps, libssl was involved as well. This is the stunnel config: setuid = nobody setgid = nogroup debug = info output = /var/adm/stunnel syslog = no options = NO_SSLv2 options = NO_SSLv3 options = NO_TLSv1 sslVersion=TLSv1.2 renegotiation=no options = SINGLE_ECDH_USE options = SINGLE_DH_USE ciphers = aes192-ctr:aes256-ctr socket = a:TCP_NODELAY=1 socket = a:SO_KEEPALIVE=1 TIMEOUTidle = 300 pid = /tmp/stunnel.pid ;include = /etc/opt/csw/stunnel/conf.d [tls-nfs-srv] accept = 31039 connect = localhost:2049 ciphers = PSK PSKsecrets = /etc/opt/csw/stunnel/psk-s.keys libwrap = yes [tls-nfs-client-1] client = yes accept = localhost:31701 connect = yyyyyy:31039 ciphers = PSK PSKsecrets = /etc/opt/csw/stunnel/psk-c.key libwrap = yes ; vim:ft=dosini Kind regards Sasha This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager.

1 0

stunnel log
by Phillip Parker 29 May '22

29 May '22

I just installed the latest version of stunnel (5.64) but there is no log file. Log file is enabled in .conf but when I run a program I don't get any log output. Help

1 0

recent Problem sending email via Blat
by Phillip Parker 25 May '22

25 May '22

I have been using stunnel and Blat for several years to send emails. Recently all the emails stopped. Interestingly I also use PowerShell to send emails and they all stopped as well. That would seem to point to something external but I have no clue what that might be. I have searched the web and have found several posts talking about (Error: Not a Socket) from Blat log but I have been unable to find a solution. In any event for stunnel I have added below the config file and the log file with debug = 7 enabled and a screen shot of netstat -an. I also believe I am running the latest version of Stunnel and Blat. Just for additional info I have attached my powershell program and the resultant error. Any help on this issue would be greatly appreciated. Incidentally I am not a stunnel or Blat person I just want things to work like they were. ; Some performance tunings socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 ; Some debugging stuff useful for troubleshooting debug = 7 output = stunnel.log ; Use it for client mode client = yes ; Service-level configuration sslversion = all ;[Protocol] protocol = smtp [ssmtp] accept = 127.0.0.1:25 connect = smtp.live.com:587 =============================================== 2022.05.21 15:03:04 LOG5[5916:5920]: Reading configuration from file stunnel.conf 2022.05.21 15:03:04 LOG7[5916:5920]: PRNG seeded successfully 2022.05.21 15:03:05 LOG7[5916:5920]: SSL context initialized for service ssmtp 2022.05.21 15:03:05 LOG5[5916:5920]: Configuration successful 2022.05.21 15:03:05 LOG5[5916:5920]: No limit detected for the number of clients 2022.05.21 15:03:05 LOG7[5916:5920]: accept socket: FD=700 allocated (non-blocking mode) 2022.05.21 15:03:05 LOG7[5916:5920]: Option SO_REUSEADDR set on accept socket 2022.05.21 15:03:05 LOG7[5916:5920]: Service ssmtp bound to 127.0.0.1:25 2022.05.21 15:03:05 LOG7[5916:5920]: Service ssmtp opened FD=700 2022.05.21 15:03:05 LOG5[5916:5920]: stunnel 4.36 on x86-pc-mingw32-gnu with OpenSSL 1.0.0d 8 Feb 2 2022.05.21 15:03:05 LOG5[5916:5920]: Threading:WIN32 SSL:ENGINE Auth:none Sockets:SELECT, IPv6 2022.05.21 15:39:56 LOG7[5916:7748]: local socket: FD=692 allocated (non-blocking mode) 2022.05.21 15:39:56 LOG7[5916:7748]: Service ssmtp accepted FD=692 from 127.0.0.1:62680 2022.05.21 15:39:56 LOG7[5916:7748]: Creating a new thread 2022.05.21 15:39:56 LOG7[5916:7748]: New thread created 2022.05.21 15:39:56 LOG7[5916:11272]: Service ssmtp started 2022.05.21 15:39:56 LOG7[5916:11272]: Option TCP_NODELAY set on local socket 2022.05.21 15:39:56 LOG5[5916:11272]: Service ssmtp accepted connection from 127.0.0.1:62680 2022.05.21 15:39:56 LOG7[5916:11272]: remote socket: FD=740 allocated (non-blocking mode) 2022.05.21 15:39:56 LOG6[5916:11272]: connect_blocking: connecting 204.79.197.212:587 2022.05.21 15:39:56 LOG7[5916:11272]: connect_blocking: s_poll_wait 204.79.197.212:587: waiting 10 seconds 2022.05.21 15:40:06 LOG3[5916:11272]: connect_blocking: s_poll_wait 204.79.197.212:587: TIMEOUTconnect exceeded 2022.05.21 15:40:06 LOG5[5916:11272]: Connection reset: 0 bytes sent to SSL, 0 bytes sent to socket Partial screen shot of netstat -an TCP 127.0.0.1:25 0.0.0.0:0 LISTENING TCP 127.0.0.1:4444 0.0.0.0:0 LISTENING TCP 127.0.0.1:5354 0.0.0.0:0 LISTENING TCP 127.0.0.1:5354 127.0.0.1:53941 ESTABLISHED TCP 127.0.0.1:5354 127.0.0.1:58943 ESTABLISHED TCP 127.0.0.1:8884 0.0.0.0:0 LISTENING TCP 127.0.0.1:9012 0.0.0.0:0 LISTENING TCP 127.0.0.1:27015 0.0.0.0:0 LISTENING TCP 127.0.0.1:33555 0.0.0.0:0 LISTENING TCP 127.0.0.1:42424 0.0.0.0:0 LISTENING TCP 127.0.0.1:53941 127.0.0.1:5354 ESTABLISHED TCP 127.0.0.1:58943 127.0.0.1:5354 ESTABLISHED TCP 127.0.0.1:60485 0.0.0.0:0 LISTENING TCP 127.0.0.1:60961 0.0.0.0:0 LISTENING TCP 127.0.0.1:62433 0.0.0.0:0 LISTENING 2022.05.21 15:40:06 LOG7[5916:11272]: Service ssmtp finished (0 left) 2022.05.21 15:40:06 LOG7[5916:11272]: str_stats: 0 blocks, 0 bytes Blat Log 2022.05.21 15:39:56 (Sat)------------Start of Session----------------- Blat v3.2.19 (build : Nov 18 2017 03:14:35) 32-bit Windows, Full, Unicode Error: Connection to server was dropped. *** Error *** SMTP server error Error: Not a socket. Error: Not a socket. 2022.05.21 15:40:06 (Sat)-------------End of Session------------------

2 1

Unexpected EOF while Reading
by Joe Sterk 24 May '22

24 May '22

Stunnel User, When we upgrade from 5.60 to 5.63 or 5.64 we start to get the unexpected eof while reading on the SSL_accept log. I re-loaded 5.60 and the error went away. Does anyone have any ideas on what to review to solve this issue? [cid:[email protected]] Joe Sterk CIO (Chief Information Officer) [Description: Description: cid:[email protected]] Insurance Services Corp. ? (972) 896-0384 (Mobile) * (707) 303-8105 (Work) * joes(a)QuieTrack.com<mailto:[email protected]>

1 0

Stunnel - TLS error unexpected eof while reading
by rick.gregson＠gmail.com 19 May '22

19 May '22

Hi All, I have recently configured stunnel on a Windows Server, it has been configured using a certificate from our internal CA and appears to be functioning ok. However we have a load balancer that is doing a health check against the service and is polling S-Tunnel availability every 5 seconds each time a poll occurs I am seeing the error posted below in the logs. 2022.05.12 10:22:55 LOG3[4113]: SSL_read: ssl/record/rec_layer_s3.c:308: error:0A000126:SSL routines::unexpected eof while reading 2022.05.12 10:22:55 LOG5[4113]: Connection reset: 217 byte(s) sent to TLS, 49 byte(s) sent to socket Can I please have some advice on how to stop this error? Thank you Rick

2 3

Getting error "CERT: Pre-verification error: self signed certificate"
by Christopher Schultz 14 May '22

14 May '22

All, I'm running stunnel 4.56 as a server on Linux, as I have been doing for a while. I require clients to connect using their own client certs and yesterday one of them expired. The client generated a new certificate and sent it to me to install, and I'm getting the error in the subject. Version details: $ sudo stunnel -help stunnel 4.56 on x86_64-koji-linux-gnu platform Compiled/running with OpenSSL 1.0.2k-fips 26 Jan 2017 Threading:PTHREAD Sockets:POLL,IPv6 SSL:ENGINE,OCSP,FIPS Auth:LIBWRAP I have set verify=4 because I expect to place the exact certificate for every client into my CAFile. This has been working for years, and when I connect using openssl s_client, I can see which client certificates the server advertises it will allow to connect, and they reflect what I expect. The server certificate is also self-signed, so I copied that into the CAFile and I'm able to connect with openssl s_client using that certificate. So I think the problem can't be that the client's certificate is self-signed. So, to recap: 1. stunnel in server mode 2. CAFile points to a collection of PEM certs 3. verify=4 4. I can connect with my own valid, trusted, self-signed certificate 5. Client cannot connect with their valid, trusted, self-signed cert Any ideas? (Note: the client DOES appear to be using their new certificate, though I can only see the subject text which could be the same, yet with a different actual certificate.) Here is the debug(7) output from an attempted connection: : Starting certificate verification: depth=0, [subject] : CERT: Pre-verification error: self signed certificate : Certificate check failed: depth=0, [subject] : SSL alert (write): fatal: unknown CA : SSL_accept: 14089086: error:14089086:SSL routines:ssl3_get_client_certificate:certificate verify failed : Connection reset: 0 byte(s) sent to SSL, 0 byte(s) sent to socket Thanks, -chris

1 1

Is stunnel really compliant with RFC 2487 / RFC 3207 ?
by Javier 13 May '22

13 May '22

Hi, first of all, I still use a 32-bit release (the latest, I think), so maybe things have changed on Stunnel since. But the statement that the protocol smtp option for a service is compliant with RFC 2487, should be 3207 (it is from 2002!), has been in the docs for ages, even in the latest version, 5.64: *** smtp Based on RFC 2487 - SMTP Service Extension for Secure SMTP over TLS *** Long ago I tested the protocol=smtp options as both, clients and server service, and I noticed that, and I think I told here to the list confirming it (maybe for some user using it on client mode), the option implied STARTTLS. Back then I didn't pay much attention to it. BUT the other day I was re-testing for a server service (own mail server sometimes I run) and... I said to my self that this shouldn't be like it was and well, I read the RFC and what tells is the following: *** A publicly-referenced SMTP server MUST NOT require use of the STARTTLS extension in order to deliver mail locally. This rule prevents the STARTTLS extension from damaging the interoperability of the Internet's SMTP infrastructure. A publicly-referenced SMTP server is an SMTP server which runs on port 25 of an Internet host listed in the MX record (or A record if an MX record is not present) for the domain name on the right hand side of an Internet mail address. *** https://datatracker.ietf.org/doc/html/rfc3207#section-4 So, if we use Stunnel to provide THE OPTION of secure TLS connections to other MTAs (MTA to MTA, or server to server) we are against the RFC itself as every connection to port 25 must be encrypted, or nothing, because, as Stunnel is the door to the port and only accepts the STARTTLS command, without redirecting any data to the mail server, no traffic on plain text reaches the server. Acting as a MSA (users - servers) there is no problem because, even if it hadn't/hasn't been widely supported, there are two ports 587 for plain text and 465 for TLS. So Stunnel could be set up to listen on 465 port only, directly accepting TLS sessions or after STARTTLS command (rejecting, in this case, those that don't want a secure channel). We have told several times, specially to newcomers (asking for http proxy, basically), that Stunnel isn't proxy, and it isn't, but in the case of a mail server it should act as is if we use it for a MTA mail server. It acts as is sending the welcome message from the mail server to the other MTA, but once the other MTA doesn't send a STARTTLS command, it closes the connection when, actually, what should do is pass all the dialog between MTAs. I think that is what Stunnel should do. And when just passing messages from mail server to the other MTA, just disable the logging for that connection. After all, the mail severs have already their own logs and there is no reason to log it on Stunnel, nor on the log screen/Stunnel window. Maybe just a line like "redirecting connection to the mail server". Said all the above, do latest versions behave differently? Do you think is a change that should be made to Stunnel to comply with the RFC, if on latest versions don't do yet, or am I wrong somewhere in my statement? Regards. P.S.: MTA: Mail Transfer Agent MSA: Mail Submission Agent MUA: Mail User Agent

3 5

GMail and OAuth 2.0
by Colin Knight 12 May '22

12 May '22

I’ve received an email from Google advising that it will no longer be able to login to Gmail with older third party apps using just username/password. Minimum login security requirements for software are now OAuth 2.0 or similar. I’m using an iPhone to post this which won’t be affected but my laptop uses POP3 collection via Foxmail and Stunnel. I must have continued access to mail on my laptop so will I have to dump Gmail or does Stunnel use OAuth 2.0 (it’s not in my config file.) Advice appreciated.

2 1

stunnel 5.64 released
by Michał Trojnara 06 May '22

06 May '22

Dear Users, I have released version 5.64 of stunnel. This release only includes Windows fixes and improvements. ### Version 5.64, 2022.05.06, urgency: MEDIUM * Security bugfixes - OpenSSL DLLs updated to version 3.0.3. * New features - Updated the pkcs11 engine for Windows. * Bugfixes - Removed the SERVICE_INTERACTIVE_PROCESS flag in "stunnel -install". Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: eebe53ed116ba43b2e786762b0c2b91511e7b74857ad4765824e7199e6faf883 stunnel-5.64.tar.gz 600e76b52a86b21f97a1af13734fdd2226c26646bb77f5f9f074ba3d5755f024 stunnel-5.64-win64-installer.exe 391db6166b22a6648fd1f1df584c13ade61c93f620e46b12ebb30b643e61d2d3 stunnel-5.64-android.zip Best regards, Mike

1 0

Handling AUTH LOGIN for SMTP
by reaperunknown＠live.com 22 Apr '22

22 Apr '22

Hello everyone. Perhaps I'm a little new with Stunnel but, I've successfully used it to get an old EarthLink MailStation compatible with GMail SMTP and POP mail. Kind of neat. That said, I wish to use Outlook, but going through the SMTP process manually via Telnet, I've found that the SMTP requires you issue "AUTH LOGIN" command, and give the username and password in Base64. If I do this manually, I can send SMTP mail all day. However, this unit is old enough that I don't think it knows how to do anything with SMTP auth. It also looks like Outlook doesn't turn SMTP auth off for Outlook.com personal accounts. Is there any way that I've missed to have Stunnel handle the AUTH LOGIN part of the SMTP process, so that device that can't, doesn't have to? Thanks!

2 1

Force PSK Authentication
by gerhard＠ats.hacktic.nl 19 Apr '22

19 Apr '22

Hi stunnel-users, Is there a way to force PSK Authentication? Current behavior is that if the client has no PSK Authentication configured, no authentication is performed and the connection proceeds even when the server has this configured: ciphers = PSK PSKsecrets = mypsk.txt Is this expected behavior? Is there a way to enforce PSK, in other words block clients without PSK Authentication? Thanks

2 1

Windows service won't start. ""The Stunnel TLS wrapper service is marked as an interactive service."
by robert.croteau＠quest.com 15 Apr '22

15 Apr '22

Window 10 LTCS (1089): "The Stunnel TLS wrapper service is marked as an interactive service. However, the system is configured to not allow interactive services. This service may not function properly." looks like starting with version 5.61, this above error appears in the System Event log. I've given a quick glance at the changes from 5.60 to 5.61 and there a lot of them. From the release notes, seems that windows services code might have been affected: New features for the Windows platform - Added client mode allowing authenticated users to view logs, reconfigure and terminate running stunnel services. - Added support for multiple GUI and service instances distinguised by the location of stunnel.conf. On GitHub, I also noticed that in the source code for src/ui_win_gui.c the service is created as follows: service=CreateService(scm, SERVICE_NAME, SERVICE_DISPLAY_NAME, SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS|SERVICE_INTERACTIVE_PROCESS, SERVICE_AUTO_START, SERVICE_ERROR_NORMAL, service_path, NULL, NULL, TEXT("TCPIP\0"), NULL, NULL);ui_win_gui.c at around line 1622 the SERVICE_INTERACTIVE_PROCESS flag is set Is this flag necessary? I guess that would be the culprit. my reason to upgrade is because of the CVE-2022-0778 OpenSSL vulnerability anyone has a workaround for this? Microsoft has fully disabled Interactive Service Detection starting with Windows 10 Build 1803 and Windows Server 2016 and 2019. So, it looks like that that Interactive services are no longer allowed and this can't be circumvented by changing some registry setting like it seems it was possible before. thank you

3 5

issue with vendor trying to use proxy for tls
by Daniel Trickett 14 Apr '22

14 Apr '22

Hi stunnelers, We have a supplier which we are attempting punchout to ecommerce site. We use the url http://local-val.dc-clic.com:8899/punchout/request/0fd1ef2b-d09a-441d-b161-… to initiate punchout. The host local-val.dc.clic.com routes to our local host, where stunnel is listening on port 8899. Our config file contains the following below. accept = local-val.dc-clic.com:8899 connect = val.dc-clic.com:443 The application fails to connect and is trying to connect using the incorrect url. Error Code: 202 Supplier Site Does Not Respond Unable to send the Login Request XML. Supplier Login URL: http://local-val.dc-clic.com:8899/punchout/request/0fd1ef2b-d09a-441d-b161-… We use stunnel as tls proxy for various suppliers and have been encountering more issues lately. I am feeling that the long string after the request is causing an issue for stunnel, but unclear to us. Our understanding is stunnel will open the connection to https:// val.dc-clic.com:443/punchout/request/0fd1ef2b-d09a-441d-b161-5ada0e226b80. Stunnel log indicates that a connection is opened to val.dc-clic.com. Any help appreciated! Thanks and best regards Dan This message and any attachment are confidential and may be privileged or otherwise protected from disclosure. If you are not the intended recipient, you must not copy this message or attachment or disclose the contents to any other person. If you have received this transmission in error, please notify the sender immediately and delete the message and any attachment from your system. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not accept liability for any omissions or errors in this message which may arise as a result of E-Mail-transmission or for damages resulting from any unauthorized changes of the content of this message and any attachment thereto. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not guarantee that this message is free of viruses and does not accept liability for any damages caused by any virus transmitted therewith. Click emdgroup.com/disclaimer<https://www.emdgroup.com/en/legal-disclaimer/mail-disclaimer.html> to access the German, French, Spanish, Portuguese, Turkish, Polish and Slovak versions of this disclaimer. Please find our Privacy Statement information by clicking here: merckgroup.com/privacy-statement-countries<https://www.merckgroup.com/en/privacy-statement/privacy-statement-countries…>

1 0

stunnel log message
by Daniel Trickett 01 Apr '22

01 Apr '22

Hello all, Happy Friday! Hope I can get some clarification on this entry from the stunnel log. The below shows up in our log, our input to stunnel is SSLv3. Is that all this is referring to? TLS state (connect): SSLv3 Thanks for your reply! Best regards, Dan This message and any attachment are confidential and may be privileged or otherwise protected from disclosure. If you are not the intended recipient, you must not copy this message or attachment or disclose the contents to any other person. If you have received this transmission in error, please notify the sender immediately and delete the message and any attachment from your system. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not accept liability for any omissions or errors in this message which may arise as a result of E-Mail-transmission or for damages resulting from any unauthorized changes of the content of this message and any attachment thereto. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not guarantee that this message is free of viruses and does not accept liability for any damages caused by any virus transmitted therewith. Click emdgroup.com/disclaimer<https://www.emdgroup.com/en/legal-disclaimer/mail-disclaimer.html> to access the German, French, Spanish, Portuguese, Turkish, Polish and Slovak versions of this disclaimer. Please find our Privacy Statement information by clicking here: merckgroup.com/privacy-statement-countries<https://www.merckgroup.com/en/privacy-statement/privacy-statement-countries…>

1 0

Stunnel version 5.63 and openssl 3.0.2 CA signature digest algorithm too weak
by c t browne 30 Mar '22

30 Mar '22

I upgraded to version 5.63 on openssl 3.02 and received a CA signature digest algorithm too week error. I tried setting the securityLevel to 2 and also to 1 and the error did not go away. I have no way to change the certificate on the remove system. Is there an way around this problem? Thanks, Carter

2 2

Can parent proxy see what's going through stunnel
by mingheng wang 28 Mar '22

28 Mar '22

Hi community, I'm using stunnel behind my company proxy like this: protocol=connect connect=proxy.ourcompany.com:3128 protocolHost=myownproxy.net:443 Since I notice that our company seems to be intercepting HTTPS because my web browser sometimes sees our company's certificate instead of the real websites'. So I want to make sure if the company proxy can see what's going through stunnel. Thanks in advance.

1 0

Stunnel aborted the workflow silently in half way
by ygaochn＠amazon.com 25 Mar '22

25 Mar '22

Hey stunnel-users, We are using stunnel as the encryption transit between our NFS client and server. Recently we detected that the stunnel aborted the workflow silently in half way for unknown reason. We'd like to understand what could be the potential reason that cause the issue. Stunnel version: 4.56/5.56, below logs are for 4.56, 5.56 is from customer report without detail log Occurance #1: 2022.03.17 02:19:58 LOG7[1105:139990955783936]: connect_blocking: s_poll_wait IP:PORT: waiting 10 seconds # -> There should be a `TIMEOUTconnect exceeded` failure if the connection failed, but there is no info about how is the waiting going on, there is no log further 2022.03.17 02:56:09 LOG7[1105:139990955789440]: Dispatching signals from the signal pipe Occurance #2: 2022.03.23 16:10:49 LOG6[19003:140551554406144]: CERT: Host name "**" matched with "**" # Aborted again, this is the handshake phase 2022.03.23 16:56:09 LOG7[19003:140551554411648]: Dispatching signals from the signal pipe From the PCAP of the #2 occurance, there is no client side cert and key send to server side, so we can rule out the network issue. 8510 2022-03-23 16:09:47.660910 A B TLSv1.2 5507 Server Hello, Certificate[Packet size limited during capture] 8511 2022-03-23 16:09:47.660919 B A TCP 68 38390 → 2049 [ACK] Seq=340 Ack=5440 Win=57472 Len=0 TSval=698509941 TSecr=1821371384 ... No other client side packet send to server side afterwards, server side are waiting Does anyone encounter this before? I searched the archive but there is no similar issue. What could cause stunnel swallow all the subsequent workflow? Thanks.

1 0

Fix the expansion of @sysconfdir@ in the sample config file
by Peter Pentchev 19 Mar '22

19 Mar '22

Hi, Thanks a lot for writing and maintaining stunnel over the years! What do you think about the attached trivial patch that makes sure @sysconfdir@ is expanded correctly in the sample config file? If something should go wrong with the attachment, it is also available at: https://salsa.debian.org/debian/stunnel/-/blob/master/debian/patches/05-sam… Thanks in advance, and keep up the great work! G'luck, Peter -- Peter Pentchev roam(a)ringlet.net roam(a)debian.org pp(a)storpool.com PGP key: http://people.FreeBSD.org/~roam/roam.key.asc Key fingerprint 2EE7 A7A5 17FC 124C F115 C354 651E EFB0 2527 DF13

1 0

the stunnel stops showing the ssl after a few hours of operation
by Daniel Cordero Gonzalez 18 Mar '22

18 Mar '22

I send an image of the error presented by the stunnel

1 0

the stunnel stops showing the ssl after a few hours of operation
by daniel＠hostingtico.com 18 Mar '22

18 Mar '22

hello, thank you very much for the opportunity to humbly ask for help, I had a server with centos 6 for approximately 3 years and the stunnel never gave me any problem, I recently changed my server with centos 7 but now after a few hours of being active it stops showing the ssl in the ports that I have configured to show shoutcast when viewing the stunnel status: service stunnel status after a few hours it shows most of the result in red and there it does not show the shoutcast in ssl, after giving restart: service stunnel restart everything returns to normal but before 6 hours the problem returns, Could someone give me a light to solve this problem, I'm running the latest version of stunnel my stunnel.conf: client=no [Orto] accept=7000 connect=208.77.20.179:8006 cert = /etc/stunnel/stunnel.pem sslVersion = TLSv1.2 [radio] accept=7002 connect=208.77.20.179:9942 cert = /etc/stunnel/stunnel.pem sslVersion = TLSv1.2 [Metro] accept=7004 connect=208.77.20.179:8014 cert = /etc/stunnel/stunnel.pem sslVersion = TLSv1.2 [arrge] accept=7006 connect=208.77.20.179:8016 cert = /etc/stunnel/stunnel.pem sslVersion = TLSv1.2 [radio2] accept=7008 connect=208.77.20.179:9932 cert = /etc/stunnel/stunnel.pem sslVersion = TLSv1.2 [Radiored] accept=7010 connect=208.77.20.179:8023 cert = /etc/stunnel/stunnel.pem sslVersion = TLSv1.2

1 0

stunnel error message
by Stephen McQuaid 18 Mar '22

18 Mar '22

Hello, I am getting the following error message in stunnel 2022.03.18 14:27:01 LOG3[0]: SSL_read (s_ssl_read_eof): Operation would block (WSAEWOULDBLOCK) (10035) 2022.03.18 14:27:01 LOG5[0]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket But when I send a second email immediately after the first one, it goes through ok, does anyone know how to resolve this please?? Regards, Stephen McQuaid Local I.T. Office, Dublin, Ireland Henkel dx - creating the next [Ein Bild, das Schild, Ende, sitzend, Front enth?lt. Automatisch generierte Beschreibung] Office : +353-1-4046338 Mobile: +353-87-2470012 stephen.mcquaid(a)henkel.com<mailto:[email protected]> www.henkeldx.com<http://www.henkeldx.com/> Have a question visit Digital Business Norden<https://henkelgroup.sharepoint.com/teams/IBSNITInfoPortal/SitePages/IBS-Nor…>

1 0

stunnel 5.63 released
by Michał Trojnara 15 Mar '22

15 Mar '22

Dear Users, I have released version 5.63 of stunnel. ### Version 5.63, 2022.03.15, urgency: HIGH * Security bugfixes - OpenSSL DLLs updated to version 3.0.2. * New features - Updated stunnel.spec to support bash completion. * Bugfixes - Fixed a PRNG initialization crash (thx to Gleydson Soares). Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: c74c4e15144a3ae34b8b890bb31c909207301490bd1e51bfaaa5ffeb0a994617 stunnel-5.63.tar.gz 723f54c28073f17b1ac095a2ab9922735c69f73fba6144a5c68cc160dc673b10 stunnel-5.63-win64-installer.exe c77850c39dfb42f95d26d4f5830a261a95c3785d8c39bdd9f28764ba43ee1d7d stunnel-5.63-android.zip Best regards, Mike

1 0

src/ssl.c:319 - RAND_get_rand_method() may return NULL
by Gleydson Soares 03 Mar '22

03 Mar '22

Hello, The following patch avoids crashess. In src/ssl.c:prng_init(), the RAND_get_rand_method() may return NULL so strict the check to skip PRNG initialization. Diff inline below, against 5.62 gsoares --- ssl.c.orig Thu Mar 3 16:10:39 2022 +++ ssl.c Thu Mar 3 16:13:17 2022 @@ -354,7 +354,7 @@ NOEXPORT int prng_init(GLOBAL_OPTIONS *global) { const RAND_METHOD *meth=RAND_get_rand_method(); /* skip PRNG initialization when no seeding methods are available */ - if(meth->status==NULL || meth->add==NULL) { + if(meth==NULL || meth->status==NULL || meth->add==NULL) { s_log(LOG_DEBUG, "No PRNG seeding methods"); return 0; /* success */ }

1 0

Error -63 when connecting to Office 365 to retrieve emails
by sedick＠logicore.co.za 01 Mar '22

01 Mar '22

Hi All, A problem started recently with error -63 when connecting to office 365 server to retrieve emails. The code I am using are as follows: * variables ChannelNo = 0 Pop3Server = 'outlook.office365.com' Pop3User = UserName Pop3Pass = Password Pop3Port = '995' ProxYServer = '127.0.0.1' ProxyPort = '110' ProxyDir = 'C:\see4OI\SSL\' ProxyExe = 'stunnel.exe' ProxyCert = 'stunnel.pem' * retreives mail in MIME format Gosub GET_EMAILS return Mail_Rec * ----------------------------------------------------------------------------------------- GET_EMAILS: * close previous session If it wasnt closed properly Code = seeClose(ChannelNo) Code = seeRelease() * attach key code Code = seeAttach(1, KeyCode) if Code < 0 then RetFlag = 1 return end * start stunnel Code = seeSetProxySSL(0, 1, ProxyDir, ProxyCert, ProxyExe) If Code < 0 Then RETURN end * connect to email server Code = seePop3ConnectSSL(ChannelNo, ProxyPort, Pop3Port, Pop3Server, Pop3User, Pop3Pass, ProxyServer) If Code < 0 Then RETURN End Help urgently required please. Stunnel version 5.42 with a special exception for OpenSSL Kind Regards, Sedick

1 0

SmtpConnectSSL question
by sportman7＠netzero.com 28 Feb '22

28 Feb '22

When I use SmtpConectSSL I establish the SSL connection but Stunnel opens a Stunnel window. I would like the connection to run without this window. Anyone know how I can stop the window from opening? Is there a setting in .conf or a parameter for SmtpConnectSSL I need?

1 0

Re: tunnel for IMAP/SMTP
by Eberhard 13 Feb '22

13 Feb '22

Just saying -- if something is deprecated it does not mean you MUST stop using it. Use an older version of the software. You can of course have both -- put the older version in one place and the newer one in another. Configure your system to use whichever version you need. The habit of always updating "just because" is sometimes not good for you 😊 E VICS, LLC Eric S Eberhard 2933 W Middle Verde Rd Camp Verde, AZ 86322 928-567-3727 (land line) 928-301-7537 (cell phone) http://www.vicsmba.com https://www.facebook.com/groups/286143052248115 -----Original Message----- From: Germano Massullo <germano.massullo(a)gmail.com> On Behalf Of Caterpillar Sent: Saturday, February 12, 2022 7:18 AM To: Josealf.rm <josealf(a)rocketmail.com> Cc: stunnel-users(a)stunnel.org Subject: [stunnel-users] Re: tunnel for IMAP/SMTP Il 10/02/22 01:56, Josealf.rm ha scritto: > OK, I see you’re using stunnel only on your client and it looks you’re > connecting using TLS 1.0 which is deprecated. > > My proposed solution runs stunnel on your server and aims to implement > a front end proxy to the imap/smtp product. This can give you the > support for new TLS versions and no need to run stunnel on your clients. No, I don't have access to the mail server machine. I just installed stunnel on a localhost VM, then lowered the VM minimum accepted TLS to 1.0, and then run Thunderbird from host machine. The latter will connect to the stunnel running in the VM _______________________________________________ stunnel-users mailing list -- stunnel-users(a)stunnel.org To unsubscribe send an email to stunnel-users-leave(a)stunnel.org

1 0

tunnel for IMAP/SMTP
by Caterpillar 12 Feb '22

12 Feb '22

Good day. I need to be able to use Thunderbird to connect to a mail server (IMAP/SMTP) that has an obsolete TLS version (1.1) and I don't want to low the TLS minimum version on my computers. For this need I would like to use stunnel between Thunderbid clients and the mail server. I tried to use tutorial [1] plus "sslVersion = all" option, but I think the guide is quite incomplete. Do you have any other guide/tutoral that is more complete? Thank you [1]: https://petermolnar.com/secure-smtp-and-imap-sessions-with-stunnel/

3 4

stunnel (5.62 and 5.59) causing high load...
by erik＠baigar.de 06 Feb '22

06 Feb '22

Hi there, I was running stunnel successfully for many years (4.26 with older openssl) wrapping http and imap and upgraded for security reasons to openssl 1.1.1 with stunnel 5.59. The platform is somewhat exotic: SPARC Solaris 10 using gcc 3.4.6. The stunnel works for imap and https without problems for some time but after heavy load conditions it starts consuming 100% CPU load although it still works. In this case it is not the DH computation as no ciphers depending on that one are used: 2022.02.06 11:56:33 LOG6[ui]: DH initialization skipped: no DH ciphersuites On the life machine it happens e.g. after some script based port scan attacks and in a way to trigger the phenomenon I found, that running a cipher enumberate for example triggers the "high-load" state. Running nmap 7.80 the command doing the job is nmap --script ssl-enum-ciphers -p PORT SERVER-IP Checking the log-file (level 7) the end of the logfile after such a burst of acitity with the stunnel ennding up at 100% CPU load looks like that: 2022.02.06 14:23:17 LOG7[39]: Deallocating application specific data for session connect address 2022.02.06 14:23:17 LOG7[39]: linger (local): Invalid argument (22) 2022.02.06 14:23:17 LOG7[39]: Local descriptor (FD=22) closed 2022.02.06 14:23:17 LOG7[39]: Service [imaps] finished (6 left) 2022.02.06 14:23:14 LOG7[main]: FD=4 events=0x1 revents=0x1 2022.02.06 14:23:17 LOG7[main]: FD=11 events=0x1 revents=0x0 2022.02.06 14:23:17 LOG7[main]: FD=12 events=0x1 revents=0x0 2022.02.06 14:23:17 LOG7[main]: FD=13 events=0x1 revents=0x0 2022.02.06 14:23:17 LOG7[main]: FD=14 events=0x1 revents=0x0 2022.02.06 14:23:17 LOG7[main]: Dispatching a signal from the signal pipe 2022.02.06 14:23:17 LOG7[main]: Processing SIGCHLD 2022.02.06 14:23:17 LOG7[main]: Retrieving pid statuses with waitpid() 2022.02.06 14:23:17 LOG7[main]: Retrieving pid statuses with waitpid() - DONE Remarkable is that some imaps (we named the IMAP service to be wrapped imaps) still seem to remain active (6 left). The last entry always is the one with the waitpid() and to be sure that it is not the while loop in that one (stunnel.c) I added an additional log entry "DONE" in the source whenever the routine is left - so it is not that easy. The workaround currently is a script monitoring the CPU usage of stunnel and killing/restarting it if >80% for extended period of time is observed, but that can just be a temporary solution. Any ideas what to try/debug locating the reason for the problem? Thanks, Erik. P.S. Experimenting with the timeouts does not alter the phenomenon. P.P.S. Here the active lines of the config file (deleted comments and unused lines to remove clutter): cert = /usr/local/etc/stunnel/stunnel.pem sslVersion = all chroot = /var/lib/stunnel/ setuid = nobody setgid = nogroup pid = /stunnel.pid socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 [imaps] accept = 14310 connect = 143 local = 127.0.0.1

1 0

Re: stunnel 5-15 minute outages
by Eberhard 05 Feb '22

05 Feb '22

I a hate to sound like a broken record – why not at least try inetd mode for a few days? If nothing else it will tell you if it is stunnel (either server issues or problems with continuing running programs) with little cost to you to try it. E VICS, LLC Eric S Eberhard 2933 W Middle Verde Rd Camp Verde, AZ 86322 928-567-3727 (land line) 928-301-7537 (cell phone) <http://www.vicsmba.com/> http://www.vicsmba.com <https://www.facebook.com/groups/286143052248115> https://www.facebook.com/groups/286143052248115 From: Steve Clement <steve3279(a)gmail.com> Sent: Saturday, February 5, 2022 3:01 AM To: john.robertson.arnold(a)gmail.com Cc: stunnel-users(a)stunnel.org Subject: [stunnel-users] Re: stunnel 5-15 minute outages We haven't taken any actions yet. We have so far believed that it was a network side issue, so we have been looking hard at the network devices and getting vendor cases open. We have been looking at packet captures to see if we can figure it out. We haven't found anything that points to the network, but still looking at that. Do you happen to have any load balancers in front of stunnel? I plan to recommend some changes to stunnel suggested in this thread. Thanks, and sorry you are facing this same issue. On Fri, Feb 4, 2022 at 11:36 PM <john.robertson.arnold(a)gmail.com <mailto:[email protected]> > wrote: I second your problem! We are experiencing what sounds like the same issue. We have had 8 outages since November. They come in pairs, roughly 48 hours apart. Each outage is between 10-12 minutes, then self resolves. I literally just came to this thread tonight while troubleshooting the latest outage. Did the suggestion in the thread work for you? _______________________________________________ stunnel-users mailing list -- stunnel-users(a)stunnel.org <mailto:[email protected]> To unsubscribe send an email to stunnel-users-leave(a)stunnel.org <mailto:[email protected]> -- Steve Clement steve3279(a)gmail.com <mailto:[email protected]> 614-632-7380

1 0

Re: stunnel 5-15 minute outages
by Eberhard 05 Feb '22

05 Feb '22

Which is why my advice is “strange.” We support so many Unix versions with thousands of users of various capabilities. I don’t want to have to learn secret tricks – especially as they change with versions of the O/S. So I use inetd – all the same on every O/S and always works. I see no reason not to do this unless you have a belief that there is a performance issue with it, which is possible I suppose but I suspect completely unlikely in modern computers. Further, inetd is running anyway so the server part is hardly affected by stunnel whereas if you use stunnel in server mode it has overhead … so a real picky person would do performance analysis and it still may be more efficient to use inetd depending on server overhead. Which is like different by O/S and computer hardware and … I worry about performance only when it actually matters. I’d rather concern myself with reliable with less maintenance on my part. My primary O/S is AIX which is stone reliable and requires little fussing with – hence using AIX to do the server part (inetd) makes my life easier. And probably 95% of the people here will disagree with me and that is fine because there is no “right” answer, just choices. I just think some people dismiss inetd out of hand because they were told a decade or two ago (I am old 😊 ) that performance was an issue and that remains the legend. And, I have helped several people overcome issues by changing to inetd, especially those with little experience in server management and/or O/S settings like Danny did (good job!). So please don’t flame me people – this is just explaining why one might consider using inetd mode, not making a case to always use it. E VICS, LLC Eric S Eberhard 2933 W Middle Verde Rd Camp Verde, AZ 86322 928-567-3727 (land line) 928-301-7537 (cell phone) <http://www.vicsmba.com/> http://www.vicsmba.com <https://www.facebook.com/groups/286143052248115> https://www.facebook.com/groups/286143052248115 From: Danny Clowes <danny0809881(a)gmail.com> Sent: Friday, February 4, 2022 1:21 PM To: Eric Eberhard <flash(a)vicsmba.com> Cc: Steve Clement <steve3279(a)gmail.com>; stunnel-users(a)stunnel.org Subject: Re: [stunnel-users] Re: stunnel 5-15 minute outages Hi, Ive been using stunnel on number of servers for very long time over all experience has been very good not had any issues or concerns with the stunnel they never crash always online. Ive just tested stunnel on debian 11 it's working brilliant. The Linux system do have limitations in place and the client will only allow so many connections before it will close down say can't take anymore connections however I edited the Linux server remove limitation in place. These where teething issues when started to use stunnel. If anyone interested I would provide hidden scrects how make stunnel work like dream. On Fri, 4 Feb 2022, 19:04 Eberhard, <flash(a)vicsmba.com <mailto:[email protected]> > wrote: I will give you strange advice assuming you are on Unix of some flavor. Use inetd. It always works or the O/S does not work 😊 It then becomes the actual server and a new instance of stunnel is fired for every connection. I use it because it is the most reliable way and takes no server software management. There is an old argument against this – it is in theory has less performance when a correction is created. I say theoretical as modern computers are so fast that creating a process millions of times does not stress a machine. I run 100s of millions of connections daily on a single computer and have zero performance issues. I also have zero issues like you described and I always had them before. Even if you do have an issue it would only affect one connection. Because each connection is unique. From your description it is the server process having an issue or perhaps some of the children not getting “clean” as they keep them running in a loop. With inetd it does it’s business and ends. There are no cross-connection or server issues. I give this advice several times a year and may ¼ take it and thank me. The rest mock the idea citing the theoretical performance difference (without even trying it) and continue to struggle. This is not just an issue with this version. Many versions have had trouble with running in a loop like that – memory management, variables not cleared, etc. And remember openssl is tied to this as well. The other thing I would recommend (also weird) is using static links. That way an install of say a new openssl (where your encryption issue appears to be now) won’t affect you. There is no way anyone is testing the software with every version of every O/S with every version of openssl. If you do a static link and have a working version, no need to change. Until a new TLS comes out or something but you can control that well when you have a static link. And that, BTW, theoretically loads faster. The program is much bigger but in need not load dynamic libraries from all over the place when it is fired up. Let me know what you find out and do 😊 E VICS, LLC Eric S Eberhard 2933 W Middle Verde Rd Camp Verde, AZ 86322 928-567-3727 (land line) 928-301-7537 (cell phone) <http://www.vicsmba.com/> http://www.vicsmba.com <https://www.facebook.com/groups/286143052248115> https://www.facebook.com/groups/286143052248115 From: Steve Clement <steve3279(a)gmail.com <mailto:[email protected]> > Sent: Friday, February 4, 2022 4:52 AM To: stunnel-users(a)stunnel.org <mailto:[email protected]> Subject: [stunnel-users] stunnel 5-15 minute outages Hello, I have been working on an issue that seems a lot like this one: https://www.stunnel.org/pipermail/stunnel-users/2011-January/002898.html We are running stunnel 5.56 and it has been working with no issues until November. Since November there have been 6 short 5-15 minute outages where we see network traffic between client and server in the packet captures, but stunnel logs stop during this period. Everything recovers on its own after this brief outage. I am looking for help in what to look for to explain this. Feb 2 14:49:29 *host* stunnel: LOG5[22565874]: Connection closed: 83 byte(s) sent to TLS, 74 byte(s) sent to socket Feb 2 15:00:36 *host* stunnel: LOG6[2705685]: Peer certificate not required We usually see dozens of messages every second, so to have an 11 minute gap in the logs is unusual. Any help would be appreciated, thank you. -- Steve Clement steve3279(a)gmail.com <mailto:[email protected]> 614-632-7380 _______________________________________________ stunnel-users mailing list -- stunnel-users(a)stunnel.org <mailto:[email protected]> To unsubscribe send an email to stunnel-users-leave(a)stunnel.org <mailto:[email protected]>

3 2

stunnel 5-15 minute outages
by Steve Clement 05 Feb '22

05 Feb '22

Hello, I have been working on an issue that seems a lot like this one: https://www.stunnel.org/pipermail/stunnel-users/2011-January/002898.html We are running stunnel 5.56 and it has been working with no issues until November. Since November there have been 6 short 5-15 minute outages where we see network traffic between client and server in the packet captures, but stunnel logs stop during this period. Everything recovers on its own after this brief outage. I am looking for help in what to look for to explain this. Feb 2 14:49:29 *host* stunnel: LOG5[22565874]: Connection closed: 83 byte(s) sent to TLS, 74 byte(s) sent to socket Feb 2 15:00:36 *host* stunnel: LOG6[2705685]: Peer certificate not required We usually see dozens of messages every second, so to have an 11 minute gap in the logs is unusual. Any help would be appreciated, thank you. -- Steve Clement steve3279(a)gmail.com 614-632-7380

2 2

Re: stunnel 5-15 minute outages
by Eberhard 04 Feb '22

04 Feb '22

I will give you strange advice assuming you are on Unix of some flavor. Use inetd. It always works or the O/S does not work 😊 It then becomes the actual server and a new instance of stunnel is fired for every connection. I use it because it is the most reliable way and takes no server software management. There is an old argument against this – it is in theory has less performance when a correction is created. I say theoretical as modern computers are so fast that creating a process millions of times does not stress a machine. I run 100s of millions of connections daily on a single computer and have zero performance issues. I also have zero issues like you described and I always had them before. Even if you do have an issue it would only affect one connection. Because each connection is unique. From your description it is the server process having an issue or perhaps some of the children not getting “clean” as they keep them running in a loop. With inetd it does it’s business and ends. There are no cross-connection or server issues. I give this advice several times a year and may ¼ take it and thank me. The rest mock the idea citing the theoretical performance difference (without even trying it) and continue to struggle. This is not just an issue with this version. Many versions have had trouble with running in a loop like that – memory management, variables not cleared, etc. And remember openssl is tied to this as well. The other thing I would recommend (also weird) is using static links. That way an install of say a new openssl (where your encryption issue appears to be now) won’t affect you. There is no way anyone is testing the software with every version of every O/S with every version of openssl. If you do a static link and have a working version, no need to change. Until a new TLS comes out or something but you can control that well when you have a static link. And that, BTW, theoretically loads faster. The program is much bigger but in need not load dynamic libraries from all over the place when it is fired up. Let me know what you find out and do 😊 E VICS, LLC Eric S Eberhard 2933 W Middle Verde Rd Camp Verde, AZ 86322 928-567-3727 (land line) 928-301-7537 (cell phone) <http://www.vicsmba.com/> http://www.vicsmba.com <https://www.facebook.com/groups/286143052248115> https://www.facebook.com/groups/286143052248115 From: Steve Clement <steve3279(a)gmail.com> Sent: Friday, February 4, 2022 4:52 AM To: stunnel-users(a)stunnel.org Subject: [stunnel-users] stunnel 5-15 minute outages Hello, I have been working on an issue that seems a lot like this one: https://www.stunnel.org/pipermail/stunnel-users/2011-January/002898.html We are running stunnel 5.56 and it has been working with no issues until November. Since November there have been 6 short 5-15 minute outages where we see network traffic between client and server in the packet captures, but stunnel logs stop during this period. Everything recovers on its own after this brief outage. I am looking for help in what to look for to explain this. Feb 2 14:49:29 *host* stunnel: LOG5[22565874]: Connection closed: 83 byte(s) sent to TLS, 74 byte(s) sent to socket Feb 2 15:00:36 *host* stunnel: LOG6[2705685]: Peer certificate not required We usually see dozens of messages every second, so to have an 11 minute gap in the logs is unusual. Any help would be appreciated, thank you. -- Steve Clement steve3279(a)gmail.com <mailto:[email protected]> 614-632-7380

2 1

Use Stunnel with CMD
by gilaguigui＠gmail.com 02 Feb '22

02 Feb '22

Hi, I am trying to use stunnel with CMD (as a service) I get pop up message for each command (service installed \ service stopped etc.) the command in CMD: stunnel.exe -install\ -uninstall.... how can I disable it? run stunnel with no pop up? thanks GG.

1 0

New to stunnel! Need help connecting to a REST API
by Tim Townsend 18 Jan '22

18 Jan '22

Hello! I need help! We have an integration from an ERP package to a REST API (Avatax) that will soon be requiring TLS 1.2 connections. Our tech platform does not have built-in support for TLS 1.2, so I'm hoping to be able to use stunnel to make that happen. Where do I start? What would the conf file section look like for this? I don't see this directly discussed in the documentation. Any help appreciated! [cid:[email protected]] Tim Townsend Programmer Earnest & Associates * Profitability Improvement Specialists Voice: 410.766.6076<tel:+14107666076> ext 210 Email: tim.townsend(a)earnestassoc.com<mailto:[email protected]> * Web: earnestassoc.com<http://www.earnestassoc.com/>

1 0

stunnel 5.62 released
by Michał Trojnara 17 Jan '22

17 Jan '22

Dear Users, I have released version 5.62 of stunnel. ### Version 5.62, 2022.01.17, urgency: MEDIUM * New features - Added a bash completion script. * Bugfixes - Fixed a transfer() loop bug. Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: 9cf5bb949022aa66c736c1326554cca27d0641605a6370274edc4951eb5bd339 stunnel-5.62.tar.gz fbfcc5759344bcafff9ff3bc6cf56c7fb75cb1244b76d4934c5d9a3eb7eee32d stunnel-5.62-win64-installer.exe 4b52ed6e4bb8293fdefb10ee8c271400a8c1749254a11b674ff690eae00b3c5e stunnel-5.62-android.zip Best regards, Mike

1 0

Re: stunnel 5.61transfer() loop executes not transferring any data Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket inetd mode
by Roberto CORRADO 17 Jan '22

17 Jan '22

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Mike, Good job! Stunnel 5.62 beta 1 work fine! """ 2022.01.16 22:08:47 LOG6[ui]: Initializing inetd mode configuration 2022.01.16 22:08:47 LOG5[ui]: stunnel 5.62 on i586-slackware-linux-gnu platform 2022.01.16 22:08:47 LOG5[ui]: Compiled/running with OpenSSL 1.1.1m 14 Dec 2021 2022.01.16 22:08:47 LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP 2022.01.16 22:08:47 LOG6[ui]: Initializing inetd mode configuration 2022.01.16 22:08:47 LOG5[ui]: Reading configuration from file /etc/stunnel/imaps.conf 2022.01.16 22:08:47 LOG5[ui]: UTF-8 byte order mark not detected 2022.01.16 22:08:47 LOG5[ui]: FIPS mode disabled 2022.01.16 22:08:47 LOG6[ui]: Compression enabled: 0 methods 2022.01.16 22:08:47 LOG6[ui]: stunnel default security level set: 2 2022.01.16 22:08:47 LOG6[ui]: Session resumption enabled 2022.01.16 22:08:47 LOG6[ui]: Loading certificate from file: /etc/stunnel/stunnel.pem 2022.01.16 22:08:47 LOG6[ui]: Certificate loaded from file: /etc/stunnel/stunnel.pem 2022.01.16 22:08:47 LOG6[ui]: Loading private key from file: /etc/stunnel/stunnel.pem 2022.01.16 22:08:47 LOG6[ui]: Private key loaded from file: /etc/stunnel/stunnel.pem 2022.01.16 22:08:47 LOG6[ui]: DH initialization needed for DHE-RSA-AES256-GCM-SHA384 2022.01.16 22:08:47 LOG6[ui]: 4096-bit DH parameters loaded 2022.01.16 22:08:47 LOG5[ui]: Configuration successful 2022.01.16 22:08:47 LOG5[0]: Service [stunnel] accepted connection from 10.19.79.235:41136 2022.01.16 22:08:47 LOG6[0]: Peer certificate not required 2022.01.16 22:08:47 LOG6[0]: No peer certificate received 2022.01.16 22:08:47 LOG6[0]: Session id: 65640462303D0DA1CD16CAB4977F22B04FFB74693150104FC69AB9FBDC48AED9 2022.01.16 22:08:47 LOG6[0]: No peer certificate received 2022.01.16 22:08:47 LOG6[0]: Session id: B9505D917FA6F2E9C8A0EF14D6E4B01C3ED54599271D93E325ED7412CA2AC5F3 2022.01.16 22:08:47 LOG6[0]: TLS accepted: new session negotiated 2022.01.16 22:08:47 LOG6[0]: TLSv1.3 ciphersuite: TLS_AES_256_GCM_SHA384 (256-bit encryption) 2022.01.16 22:08:47 LOG6[0]: Peer temporary key: X25519, 253 bits 2022.01.16 22:08:47 LOG6[0]: Local mode child started (PID=16984) 2022.01.16 22:08:47 LOG6[0]: TLS closed (SSL_read) 2022.01.16 22:08:47 LOG6[0]: Read socket closed (readsocket) 2022.01.16 22:08:47 LOG6[0]: SSL_shutdown successfully sent close_notify alert 2022.01.16 22:08:47 LOG5[0]: Connection closed: 979 byte(s) sent to TLS, 128 byte(s) sent to socket """ Thanks a lot! - -Roberto -----BEGIN PGP SIGNATURE----- iEYEARECAAYFAmHkjDoACgkQWVOoL214ZeGntwCbBtV1G/J2uThR06ftFC+F2XTP KeQAnjnCTOrk26zzcsNsCOQoWg54MWhD =alm2 -----END PGP SIGNATURE----- ----- Original Message ----- Sent: Sunday, January 16, 2022 9:52 PM Michał Trojnara wrote: > Hi Roberto, > > Could you try https://www.stunnel.org/downloads/beta/stunnel-5.62b1.tar.gz ? > > Best regards, > Mike

2 1

I NEED A HELP TO SETUP THE SSL/TLS EMAILS SUPPORT
by Muj 01 Jan '22

01 Jan '22

HI TECHNICAL SUPPORT, FIRSTLY, I AM APOLOGIZING TO YOU FOR WRITING WITH LARGE CAPS ONLY, IT IS BECAUSE RECENTLY I GOT A BRAIN STROKE AND AM NOT RECOVERED YET. AS FOR MY ISSUE, TO UNDERSTAND IT BETTER, THE FOLLOWING IS MY INFO. - I HAVE AN OLD WINDOWS-XP 32BIT OS. - I AM USING TERABYTE 2.99 TO BACKUP AND RESTORE MY OS, BUT LOOSING MANY EMAILS BECAUSE TERABYTE IS NO LONGER SUPPORTING 2.99 VERSION. THEY SUPPORT RESTORING ALL EMAILS BEGINNING FROM 3 VERSION. THEREFORE, THEY HAVE RECOMMENDED ME TO CONTACT YOU DIRECTLY. NOW WHAT I DID SO FAR. - I DOWNLOADED AND INSTALLED YOUR STUNNEL 4.53 - AFTER AUTOMATIC SETTING, EDITING STUNNEL.CONF FILE, MAKING SOME CHANGES IN IT AND SAVING IT, THE SERVER WENT DOWN. ATTACHED PLEASE FIND STUNNEL.CONF TXT FILE. - BECAUSE THE SERVER WENT DOWN, I TRIED TO DOWNLOAD AND INSTALL STUNNEL AGAIN, BUT ALWAYS GOT THE SAME ERROR MESSAGE.PLEASE CAN YOU HELP ME WITH THIS ISSUE? - I HAVE 3 POP3 EMAIL ACCOUNTS AND 1 IMAP. ALL REQUIRE A CONNECTION SECURITY SSL/TLS. *PLEASE, I NEED TO KNOW HOW **TO COMPLETELY REMOVE THE CURRENT STUNNEL PROGRAM AND AFTER THAT, WHAT STUNNEL VERSION I SHOULD **DOWNLOAD AGAIN **TO BE ABLE TO SET IT UP*. AFTER A SUCCESSFUL NEW INSTALLATION I WOULD GIVE YOU MORE NEEDED INFO FOR SETTING UP MY EMAILS. PLEASE LET ME KNOW IN YOUR BEST CONVENIENCE AND HAVE A BEAUTIFUL NEW YEAR 2022. KIND REGARDS, MARTIN

1 0

stunnel 5.61transfer() loop executes not transferring any data Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket inetd mode
by Roberto CORRADO 29 Dec '21

29 Dec '21

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 """ 2021.12.28 14:03:40 LOG6[ui]: Initializing inetd mode configuration 2021.12.28 14:03:40 LOG5[ui]: stunnel 5.61 on i586-slackware-linux-gnu platform 2021.12.28 14:03:40 LOG5[ui]: Compiled/running with OpenSSL 1.1.1m 14 Dec 2021 2021.12.28 14:03:40 LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP 2021.12.28 14:03:40 LOG6[ui]: Initializing inetd mode configuration 2021.12.28 14:03:40 LOG5[ui]: Reading configuration from file /etc/stunnel/imaps.conf 2021.12.28 14:03:40 LOG5[ui]: UTF-8 byte order mark not detected 2021.12.28 14:03:40 LOG5[ui]: FIPS mode disabled 2021.12.28 14:03:40 LOG6[ui]: Compression enabled: 0 methods 2021.12.28 14:03:40 LOG6[ui]: stunnel default security level set: 2 2021.12.28 14:03:40 LOG6[ui]: Session resumption enabled 2021.12.28 14:03:40 LOG6[ui]: Loading certificate from file: /etc/stunnel/stunnel.pem 2021.12.28 14:03:40 LOG6[ui]: Certificate loaded from file: /etc/stunnel/stunnel.pem 2021.12.28 14:03:40 LOG6[ui]: Loading private key from file: /etc/stunnel/stunnel.pem 2021.12.28 14:03:40 LOG6[ui]: Private key loaded from file: /etc/stunnel/stunnel.pem 2021.12.28 14:03:40 LOG6[ui]: DH initialization skipped: no DH ciphersuites 2021.12.28 14:03:40 LOG5[ui]: Configuration successful 2021.12.28 14:03:40 LOG5[0]: Service [stunnel] accepted connection from 127.0.0.1:40876 2021.12.28 14:03:40 LOG6[0]: Peer certificate not required 2021.12.28 14:03:40 LOG6[0]: No peer certificate received 2021.12.28 14:03:40 LOG6[0]: Session id: 0E092C2715D12901219C3E0F54DFA029F7C50040C7EC8F8C88211BA6883B9D1F 2021.12.28 14:03:40 LOG6[0]: No peer certificate received 2021.12.28 14:03:40 LOG6[0]: Session id: 26CFB9D13C499CE27C4ED1575FDF3FB2604C616418BA6068849B49EF75AF2162 2021.12.28 14:03:40 LOG6[0]: TLS accepted: new session negotiated 2021.12.28 14:03:40 LOG6[0]: TLSv1.3 ciphersuite: TLS_AES_256_GCM_SHA384 (256-bit encryption) 2021.12.28 14:03:40 LOG6[0]: Peer temporary key: X25519, 253 bits 2021.12.28 14:03:40 LOG6[0]: Local mode child started (PID=4997) 2021.12.28 14:03:40 LOG3[0]: transfer() loop executes not transferring any data 2021.12.28 14:03:40 LOG3[0]: please report the problem to Michal.Trojnara(a)stunnel.org 2021.12.28 14:03:40 LOG3[0]: stunnel 5.61 on i586-slackware-linux-gnu platform 2021.12.28 14:03:40 LOG3[0]: Compiled/running with OpenSSL 1.1.1m 14 Dec 2021 2021.12.28 14:03:40 LOG3[0]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP 2021.12.28 14:03:40 LOG3[0]: protocol=TLSv1.3, SSL_pending=0, SSL_has_pending=0 2021.12.28 14:03:40 LOG3[0]: sock_open_rd=Y, sock_open_wr=Y 2021.12.28 14:03:40 LOG3[0]: SSL_RECEIVED_SHUTDOWN=n, SSL_SENT_SHUTDOWN=n 2021.12.28 14:03:40 LOG3[0]: sock_can_rd=n, sock_can_wr=n 2021.12.28 14:03:40 LOG3[0]: ssl_can_rd=n, ssl_can_wr=n 2021.12.28 14:03:40 LOG3[0]: read_wants_read=Y, read_wants_write=n 2021.12.28 14:03:40 LOG3[0]: write_wants_read=n, write_wants_write=Y 2021.12.28 14:03:40 LOG3[0]: shutdown_wants_read=n, shutdown_wants_write=n 2021.12.28 14:03:40 LOG3[0]: socket input buffer: 154 byte(s), TLS input buffer: 0 byte(s) 2021.12.28 14:03:40 LOG5[0]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket """ """ debug = info output = /var/log/stunnel-imaps.log cert = /etc/stunnel/stunnel.pem exec = /usr/sbin/imapd execargs = imapd sslVersion = all options = NO_SSLv2 options = NO_SSLv3 """ -----BEGIN PGP SIGNATURE----- iEYEARECAAYFAmHLE48ACgkQWVOoL214ZeFpYwCfe+qv09KWSfjNixhhcb5MJbr2 yAkAoKOyXZJwnKddSXYzIhbi7k1yPkoU =oGR+ -----END PGP SIGNATURE-----

1 0

Config to only listen when connect port is up
by roartysa＠gmail.com 23 Dec '21

23 Dec '21

Is there a config flag that can be set in the conf file that will tell stunnel to listen on the https accept port only when the connect port is up and listening? The issue i am trying to address is when a load balancer talks to a server, I need to make sure the port that stunnel redirects to is healthy. Right now the load balancer will send traffic to the port all the time regardless of the health of the port that stunnel redirects the traffic to.

2 1

stunnel 5.61 released
by Michał Trojnara 22 Dec '21

22 Dec '21

Dear Users, I have released version 5.61 of stunnel. ### Version 5.61, 2021.12.22, urgency: LOW * New features sponsored by the University of Maryland - Added new "protocol = capwin" and "protocol = capwinctrl" configuration file options. * New features for the Windows platform - Added client mode allowing authenticated users to view logs, reconfigure and terminate running stunnel services. - Added support for multiple GUI and service instances distinguised by the location of stunnel.conf. - Improved log window scrolling. - Added a new 'Pause auto-scroll' GUI checkbox. - Double click on the icon tray replaced with single click. - OpenSSL DLLs updated to version 3.0.1. * Other new features - Rewritten the testing framework in python (thx to Peter Pentchev for inspiration and initial framework). - Added support for missing SSL_set_options() values. - Updated stunnel.spec to support RHEL8. * Bugfixes - Fixed OpenSSL 3.0 build. - Fixed reloading configuration with "systemctl reload stunnel.service". - Fixed incorrect messages logged for OpenSSL errors. - Fixed printing IPv6 socket option defaults on FreeBSD. Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: 91ea0ca6482d8f7e7d971ee64ab4f86a2817d038a372f0893e28315ef2015d7a stunnel-5.61.tar.gz 19c5ff1f4101af1e69585328303c14249db2ec9063542101ca31edb6f6cc502f stunnel-5.61-win64-installer.exe 928ec94690564498bf523228946b2cdc90c7e346d6f0baf1f71b76cbe769b96c stunnel-5.61-android.zip Best regards, Mike

1 0

Log4j Vulnerability
by Tracy Drake - IQGC-C 17 Dec '21

17 Dec '21

Hello! Can you please tell me if Stunnel uses log4j and/or if it is vulnerable to it? Your feedback would be greatly appreciated! Thanks in advance! -- *TRACY DRAKE | CSM URSA/Infoconnect Training and Support* GSA COMET Hale Bopp Contract Work Phone: 704-253-5193 | Email: tracy.drake(a)gsa.gov

2 1

issue with connection sending cxml out
by Daniel Trickett 08 Dec '21

08 Dec '21

Hi, We are trying to send a cxml message from an old app using ssl_v3 to a client server using tls 1.2. We negotiate a connection and then the below happens. Any thoughts? This is on our test server. 2021.12.08 14:26:55 LOG6[12]: TLS connected: new session negotiated 2021.12.08 14:26:55 LOG6[12]: TLSv1.2 ciphersuite: ECDHE-RSA-AES128-GCM-SHA256 (128-bit encryption) 2021.12.08 14:26:55 LOG7[12]: Compression: null, expansion: null 2021.12.08 14:26:55 LOG7[12]: TLS alert (read): warning: close notify <<< 2021.12.08 14:26:55 LOG6[12]: TLS closed (SSL_read) 2021.12.08 14:26:55 LOG7[12]: Sent socket write shutdown 2021.12.08 14:26:55 LOG6[12]: Read socket closed (readsocket) 2021.12.08 14:26:55 LOG7[12]: Sending close_notify alert 2021.12.08 14:26:55 LOG7[12]: TLS alert (write): warning: close notify 2021.12.08 14:26:55 LOG6[12]: SSL_shutdown successfully sent close_notify alert 2021.12.08 14:26:55 LOG5[12]: Connection closed: 10187 byte(s) sent to TLS, 561 byte(s) sent to socket Best regards, Dan This message and any attachment are confidential and may be privileged or otherwise protected from disclosure. If you are not the intended recipient, you must not copy this message or attachment or disclose the contents to any other person. If you have received this transmission in error, please notify the sender immediately and delete the message and any attachment from your system. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not accept liability for any omissions or errors in this message which may arise as a result of E-Mail-transmission or for damages resulting from any unauthorized changes of the content of this message and any attachment thereto. Merck KGaA, Darmstadt, Germany and any of its subsidiaries do not guarantee that this message is free of viruses and does not accept liability for any damages caused by any virus transmitted therewith. Click emdgroup.com/disclaimer<https://www.emdgroup.com/en/legal-disclaimer/mail-disclaimer.html> to access the German, French, Spanish, Portuguese, Turkish, Polish and Slovak versions of this disclaimer. Please find our Privacy Statement information by clicking here emdgroup.com/en/privacy-statement.html<https://www.emdgroup.com/en/privacy-statement.html>

1 0

Revert automatically to https
by cnocera＠hyhat.com 08 Dec '21

08 Dec '21

With stunnel, is there a way for the website to automatically revert to https by just typing in the url without https:// in front of it?

1 0

Insecure file permissions on /etc/ssl/private.key
by jose isaias cabrera 29 Nov '21

29 Nov '21

Greetings! I have duckduckgo'ed and I have not found an answer, but what should be the permissions for the private key since the stunnel is giving me a warning/error regarding that: ... [ ] Loading private key from file: /etc/ssl/private.key [:] Insecure file permissions on /etc/ssl/private.key [ ] Private key loaded from file: /etc/ssl/private.key ... this is that I have set: jic@web:~$ ls -l /etc/ssl/private.key -rw-r--r-- 1 root www-data 1702 Oct 13 02:54 /etc/ssl/private.key the www-data is the user that runs the website. All is running well, apparently, but, I would like to set the correct permission on the private.key file. Thanks for your support. josé -- What if eternity is real? Where will you spend it? Hmmmm...

4 6

Althttpd web server setup using ZeroSSL
by jose isaias cabrera 29 Nov '21

29 Nov '21

Greetings! I have the ssl files from ZeroSSL, and I am trying to set up https using stunnel4 on an ubuntu server. I am new to https, I would love some of your help setting this up. Here is what I have done so far: 1. Installed Althttpd and http is working fine on the home network and from the external network. 2. I have installed stunnel4 on the ubuntu server jcabrera@selva:~$ stunnel -v [ ] Clients allowed=500 [.] stunnel 5.56 on x86_64-pc-linux-gnu platform [.] Compiled with OpenSSL 1.1.1c 28 May 2019 [.] Running with OpenSSL 1.1.1f 31 Mar 2020 [.] Threading:PTHREAD Sockets:POLL,IPv6,SYSTEMD TLS:ENGINE,FIPS,OCSP,PSK,SNI Auth:LIBWRAP [ ] errno: (*__errno_location ()) [!] Invalid configuration file name "-v" [!] realpath: No such file or directory (2) [ ] Deallocating section defaults 3. I have placed the ZeroSSl ssl files on the ssl directory as per ZeroSSL instructions jcabrera@selva:~$ ls -l /etc/ssl/*.crt -rw-r--r-- 1 root root 2431 Oct 20 16:27 /etc/ssl/ca_bundle.crt -rw-r--r-- 1 root root 2354 Oct 20 16:31 /etc/ssl/certificate.crt root@selva:/home/jcabrera# ls -l /etc/ssl/private/*.key -rw-r--r-- 1 root root 1702 Oct 20 16:33 /etc/ssl/private/private.key 4. Created the the /etc/stunnel/stunnel.conf file with these entries: root@selva:/home/jcabrera# cat /etc/stunnel/stunnel.conf cert = /etc/ssl/certificate.crt key = /etc/ssl/private/private.key \[https\] accept = :::443 TIMEOUTclose = 0 exec = /usr/bin/althttpd execargs = /usr/bin/althttpd -logfile ~/www/http.log -root ~/www -user www-data -https 1 And, I don't know what else to do. Any help would be greatly appreciated. Thanks. josé -- What if eternity is real? Where will you spend it? Hmmmm...

2 3

Office 365 connections stopped working
by Ben Bazian 26 Nov '21

26 Nov '21

This has been working for years and recently stopped. I am a novice here. Can someone look at this and please tell me what is happening? It is an old server that does not support TLS so we put Stunnel in front of it. I am sure the version of stunnel is pretty old. Maybe a TLS level issue? 2021.10.26 14:47:30 LOG7[21968:139797665822784]: SSL options set: 0x01000004 2021.10.26 14:47:30 LOG6[21968:139797665822784]: Initializing service [SMTP Outgoing] 2021.10.26 14:47:30 LOG7[21968:139797665822784]: SSL options set: 0x01000004 2021.10.26 14:47:30 LOG6[21968:139797665822784]: Initializing service [IMAP] 2021.10.26 14:47:30 LOG7[21968:139797665822784]: SSL options set: 0x01000004 2021.10.26 14:47:30 LOG5[21968:139797665822784]: Configuration successful 2021.10.26 14:47:30 LOG7[21968:139797665822784]: Service [POP3 Incoming] (FD=12) bound to 0.0.0.0:110 2021.10.26 14:47:30 LOG7[21968:139797665822784]: Service [SMTP Outgoing] (FD=13) bound to 0.0.0.0:25 2021.10.26 14:47:30 LOG7[21968:139797665822784]: Service [IMAP] (FD=14) bound to 0.0.0.0:143 2021.10.26 14:47:30 LOG7[21974:139797665822784]: Created pid file /var/run/stunnel.pid 2021.10.26 14:48:30 LOG7[21974:139797665822784]: Service [IMAP] accepted (FD=3) from 10.55.3.159:1852 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Service [IMAP] started 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Waiting for a libwrap process 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Acquired libwrap process #0 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Releasing libwrap process #0 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Released libwrap process #0 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Service [IMAP] permitted by libwrap from 10.55.3.159:1852 2021.10.26 14:48:30 LOG5[21974:139797665818368]: Service [IMAP] accepted connection from 10.55.3.159:1852 2021.10.26 14:48:30 LOG6[21974:139797665818368]: connect_blocking: connecting 52.96.87.226:993 2021.10.26 14:48:30 LOG7[21974:139797665818368]: connect_blocking: s_poll_wait 52.96.87.226:993: waiting 10 seconds 2021.10.26 14:48:30 LOG5[21974:139797665818368]: connect_blocking: connected 52.96.87.226:993 2021.10.26 14:48:30 LOG5[21974:139797665818368]: Service [IMAP] connected remote server from 10.55.3.200:51358 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Remote socket (FD=16) initialized 2021.10.26 14:48:30 LOG7[21974:139797665818368]: SNI: sending servername: outlook.office365.com 2021.10.26 14:48:30 LOG7[21974:139797665818368]: SSL state (connect): before/connect initialization 2021.10.26 14:48:30 LOG7[21974:139797665818368]: SSL state (connect): SSLv3 write client hello A 2021.10.26 14:48:30 LOG3[21974:139797665818368]: SSL_connect: Peer suddenly disconnected 2021.10.26 14:48:30 LOG5[21974:139797665818368]: Connection reset: 0 byte(s) sent to SSL, 0 byte(s) sent to socket 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Remote socket (FD=16) closed 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Local socket (FD=3) closed 2021.10.26 14:48:30 LOG7[21974:139797665818368]: Service [IMAP] finished (0 left)

4 5

setting permissions on a unix socket
by David Mandelberg 03 Nov '21

03 Nov '21

Hi, Is there any way for stunnel to set permissions on a unix socket created with the `accept` option? I see setuid and setgid at https://www.stunnel.org/static/stunnel.html but nothing about a umask or permissions. P.S. The link on https://www.stunnel.org/lists.html to see the archive is broken. Apologies if this has come up before.

1 0

Stunnel connection to Akamai Cloud Servers (Hostheaders) with SNI
by Alan C. Bonnici 06 Oct '21

06 Oct '21

Hi, I am trying to use stunnel to exchange data with a service hosted on Akamai Servers. There is a need to implement SNI. In posts dated from 2016 which I found online, Stunnel did not support Host Headers. Is there a workaround, or has Stunnel implemented this functionality? I will be testing using postman. A sample config to get me going would really be appreciated. The URL is related to plivo. It is ak-api.plivo.com. Thank you in anticipation.

3 6

Is it possible to inhibit writing the stunnel logs to the / var / log / messages file?
by simona vittori 28 Sep '21

28 Sep '21

Hello, I ask you if it's possible to inhibit writing the stunnel logs to the / var / log / messages file. How do you it? Thank you in advance Bye Simona

2 1

Need a clean way to reject a client IP
by robin.kerdiles＠emanrisk.fr 28 Sep '21

28 Sep '21

Hello everyone, I'm doing a few tests on a dockerized service for stunnel under Alpine. stunnel -version stunnel 5.60 on x86_64-alpine-linux-musl platform Compiled with OpenSSL 1.1.1k 25 Mar 2021 Running with OpenSSL 1.1.1l 24 Aug 2021 Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI If I set a wrong certificate on client side, my server logs get spammed with these lines : 2021.09.28 07:43:52 LOG5[66]: Service [***] accepted connection from *** 2021.09.28 07:43:52 LOG4[66]: CERT: Pre-verification error: unable to get local issuer certificate 2021.09.28 07:43:52 LOG4[66]: Rejected by CERT at depth=2: C=***, O=***, CN=*** 2021.09.28 07:43:52 LOG3[66]: SSL_accept: ssl/statem/statem_srvr.c:3711: error:1417C086:SSL routines:tls_process_client_certificate:certificate verify failed 2021.09.28 07:43:52 LOG5[66]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket The cpu usage goes up to 35% and it seems there is no way to set a timeout before trying to reconnect on client side (which is not the perfect fix by the way). On server side, I don't know if we are supposed to be able to do something about that (for example rate limiting the requests ?). Even the fail2ban filter doesn't seem to support this case. And anyway it seems it requires manual patching on stunnel source code for the logs. Would it be possible to put on the same line the client IP and a message about the connection which has been rejected ? fail2ban filter : https://github.com/fail2ban/fail2ban/blob/master/config/filter.d/stunnel.co… What would be appreciated -> a log line in this format : 2021.09.28 07:43:52 LOG4[66]: HOST has been rejected by CERT at depth=2: C=***, O=***, CN=*** Of course, I don't have in mind the other possible cases (missing cert, etc...). Thank you in advance, Robin KERDILES

2 1

Disguising HTTP 503 services unavailable
by Haruka Takagi 18 Sep '21

18 Sep '21

It is my understanding that; stunnel clients give up connecting servers because of HTTP 503 services unavailable, tunneling failure causes stunnel clients to notify original senders of errors, and original senders acknowledge communication failure and stop program. I would like stunnel clients to reconnecting servers in cases of 503 and not to notify original senders of failure, in order that original senders are unaware of failure and can continue program. If possible, I want to do this by writing stunnel.conf without modifying souce codes. Is this configuration possible?

4 5

protocol = proxy with redirect
by Rob Hoes 15 Sep '21

15 Sep '21

Hi, I am using client certificate verification with the redirect option, so that the connection gets transferred to a separate socket in case the certificate is not accepted (rather than dropping the connection). This works well, unless I add the option “protocol = proxy” in order to get the client’s TCP params passed on. In this case, the redirect option seems to be ignored. Are the “redirect” and “protocol = proxy” options incompatible with one another? Is there an alternative? Thanks, Rob

2 1

How to resolve DNS by stunnel?
by shiga＠smart-cast.co.jp 14 Sep '21

14 Sep '21

Hi, I'm facing DNS issues when connecting to a server using a dynamic IP address. I think stunnel refers to DNS at startup, so if the IP address changes in the middle, it will get a connection error. Can this be resolved with the "delay=on" option? I'm looking for a way to handle a dynamic IP address in stunnel. Thanks.

2 1

Session reuse problem
by Alen Loncaric 10 Sep '21

10 Sep '21

Hi guys, any reason my stunnel would not reuse sessions? 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): before SSL initialization 2021.09.09 13:14:00 LOG6[8]: writesocket: Socket is closed 2021.09.09 13:14:00 LOG7[9]: Initializing application specific data for session authenticated 2021.09.09 13:14:00 LOG5[8]: Connection closed: 170 byte(s) sent to TLS, 32768 byte(s) sent to socket 2021.09.09 13:14:00 LOG7[8]: Remote descriptor (FD=10) closed 2021.09.09 13:14:00 LOG7[8]: Local descriptor (FD=3) closed 2021.09.09 13:14:00 LOG7[8]: Service [squid] finished 2021.09.09 13:14:00 LOG7[ui]: Found 1 ready file descriptor(s) 2021.09.09 13:14:00 LOG7[ui]: FD=4 events=0x1 revents=0x1 2021.09.09 13:14:00 LOG7[ui]: FD=10 events=0x1 revents=0x0 2021.09.09 13:14:00 LOG7[ui]: Dispatching a signal from the signal pipe 2021.09.09 13:14:00 LOG7[ui]: Processing SIGCHLD 2021.09.09 13:14:00 LOG7[ui]: Retrieving pid statuses with waitpid() 2021.09.09 13:14:00 LOG6[ui]: Process 1933 finished with code 0 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS write client hello 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS write client hello 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS read server hello 2021.09.09 13:14:00 LOG6[9]: Certificate verification disabled 2021.09.09 13:14:00 LOG6[9]: Certificate verification disabled 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS read server certificate 2021.09.09 13:14:00 LOG6[9]: Client certificate not requested 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS read server done 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS write client key exchange 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS write change cipher spec 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS write finished 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS write finished 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS read server session ticket 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS read change cipher spec 2021.09.09 13:14:00 LOG7[9]: TLS state (connect): SSLv3/TLS read finished 2021.09.09 13:14:00 LOG7[9]: New session callback 2021.09.09 13:14:00 LOG7[9]: Peer certificate was cached (2037 bytes) 2021.09.09 13:14:00 LOG6[9]: Session id: DC783240F69C6910A2F8B9829504840EF619E30A14FEA982C944FBFB6828555F 2021.09.09 13:14:00 LOG7[9]: 1 client connect(s) requested 2021.09.09 13:14:00 LOG7[9]: 1 client connect(s) succeeded 2021.09.09 13:14:00 LOG7[9]: 0 client renegotiation(s) requested 2021.09.09 13:14:00 LOG7[9]: 0 session reuse(s) 2021.09.09 13:14:00 LOG6[9]: TLS connected: new session negotiated 2021.09.09 13:14:00 LOG6[9]: TLSv1.2 ciphersuite: AES128-GCM-SHA256 (128-bit encryption) 2021.09.09 13:14:00 LOG3[9]: SSL_get_peer_tmp_key: Peer suddenly disconnected 2021.09.09 13:14:00 LOG7[9]: Compression: null, expansion: null 2021.09.09 13:14:01 LOG6[9]: Read socket closed (readsocket) 2021.09.09 13:14:01 LOG7[9]: Sending close_notify alert 2021.09.09 13:14:01 LOG6[9]: socket fd: Broken pipe (32) 2021.09.09 13:14:01 LOG7[9]: TLS alert (write): warning: close notify 2021.09.09 13:14:01 LOG6[9]: SSL_shutdown successfully sent close_notify alert 2021.09.09 13:14:01 LOG6[9]: writesocket: Socket is closed 2021.09.09 13:14:01 LOG5[9]: Connection closed: 170 byte(s) sent to TLS, 32768 byte(s) sent to socket 2021.09.09 13:14:01 LOG7[9]: Remote descriptor (FD=10) closed 2021.09.09 13:14:01 LOG7[9]: Local descriptor (FD=3) closed 2021.09.09 13:14:01 LOG7[9]: Service [squid] finished 2021.09.09 13:14:01 LOG7[ui]: Found 1 ready file descriptor(s) 2021.09.09 13:14:01 LOG7[ui]: FD=4 events=0x1 revents=0x1 2021.09.09 13:14:01 LOG7[ui]: FD=10 events=0x1 revents=0x0 2021.09.09 13:14:01 LOG7[ui]: Dispatching a signal from the signal pipe 2021.09.09 13:14:01 LOG7[ui]: Processing SIGCHLD 2021.09.09 13:14:01 LOG7[ui]: Retrieving pid statuses with waitpid() 2021.09.09 13:14:01 LOG6[ui]: Process 1934 finished with code 0 2021.09.09 13:14:03 LOG7[ui]: Found 1 ready file descriptor(s) 2021.09.09 13:14:03 LOG7[ui]: FD=4 events=0x1 revents=0x0 2021.09.09 13:14:03 LOG7[ui]: FD=10 events=0x1 revents=0x1 2021.09.09 13:14:03 LOG7[ui]: Service [squid] accepted (FD=3) from 127.0.0.1:49567 2021.09.09 13:14:03 LOG7[10]: Service [squid] started 2021.09.09 13:14:03 LOG7[10]: Setting local socket options (FD=3) 2021.09.09 13:14:03 LOG7[10]: Option TCP_NODELAY set on local socket 2021.09.09 13:14:03 LOG5[10]: Service [squid] accepted connection from 127.0.0.1:49567 2021.09.09 13:14:03 LOG6[10]: s_connect: connecting 44.44.44.44:522 2021.09.09 13:14:03 LOG7[10]: s_connect: s_poll_wait 44.44.44.44:522: waiting 10 seconds 2021.09.09 13:14:03 LOG7[10]: FD=6 events=0x1 revents=0x0 2021.09.09 13:14:03 LOG7[10]: FD=10 events=0x5 revents=0x0 2021.09.09 13:14:03 LOG5[10]: s_connect: connected 44.44.44.44:522 2021.09.09 13:14:03 LOG5[10]: Service [squid] connected remote server from 10.1.3.57:42843 2021.09.09 13:14:03 LOG7[10]: Setting remote socket options (FD=10) 2021.09.09 13:14:03 LOG7[10]: Option TCP_NODELAY set on remote socket 2021.09.09 13:14:03 LOG7[10]: Remote descriptor (FD=10) initialized 2021.09.09 13:14:03 LOG6[10]: SNI: sending servername: 44.44.44.44 2021.09.09 13:14:03 LOG6[10]: Peer certificate not required 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): before SSL initialization 2021.09.09 13:14:03 LOG7[10]: Initializing application specific data for session authenticated 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS write client hello 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS write client hello 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS read server hello 2021.09.09 13:14:03 LOG6[10]: Certificate verification disabled 2021.09.09 13:14:03 LOG6[10]: Certificate verification disabled 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS read server certificate 2021.09.09 13:14:03 LOG6[10]: Client certificate not requested 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS read server done 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS write client key exchange 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS write change cipher spec 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS write finished 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS write finished 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS read server session ticket 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS read change cipher spec 2021.09.09 13:14:03 LOG7[10]: TLS state (connect): SSLv3/TLS read finished 2021.09.09 13:14:03 LOG7[10]: New session callback 2021.09.09 13:14:03 LOG7[10]: Peer certificate was cached (2037 bytes) 2021.09.09 13:14:03 LOG6[10]: Session id: 85FD50E2A9D57B12D315C834EBA949CF015B7776C6A18486B06CE53F4C52D689 2021.09.09 13:14:03 LOG7[10]: 1 client connect(s) requested 2021.09.09 13:14:03 LOG7[10]: 1 client connect(s) succeeded 2021.09.09 13:14:03 LOG7[10]: 0 client renegotiation(s) requested 2021.09.09 13:14:03 LOG7[10]: 0 session reuse(s) 2021.09.09 13:14:03 LOG6[10]: TLS connected: new session negotiated 2021.09.09 13:14:03 LOG6[10]: TLSv1.2 ciphersuite: AES128-GCM-SHA256 (128-bit encryption) 2021.09.09 13:14:03 LOG3[10]: SSL_get_peer_tmp_key: Peer suddenly disconnected 2021.09.09 13:14:03 LOG7[10]: Compression: null, expansion: null 2021.09.09 13:14:03 LOG7[ui]: Found 1 ready file descriptor(s) 2021.09.09 13:14:03 LOG7[ui]: FD=4 events=0x1 revents=0x0 2021.09.09 13:14:03 LOG7[ui]: FD=10 events=0x1 revents=0x1 2021.09.09 13:14:03 LOG7[ui]: Service [squid] accepted (FD=3) from 127.0.0.1:49569 2021.09.09 13:14:03 LOG7[11]: Service [squid] started 2021.09.09 13:14:03 LOG7[11]: Setting local socket options (FD=3) 2021.09.09 13:14:03 LOG7[11]: Option TCP_NODELAY set on local socket 2021.09.09 13:14:03 LOG5[11]: Service [squid] accepted connection from 127.0.0.1:49569 2021.09.09 13:14:03 LOG6[11]: s_connect: connecting 44.44.44.44:522 2021.09.09 13:14:03 LOG7[11]: s_connect: s_poll_wait 44.44.44.44:522: waiting 10 seconds 2021.09.09 13:14:03 LOG7[11]: FD=6 events=0x1 revents=0x0 2021.09.09 13:14:03 LOG7[11]: FD=10 events=0x5 revents=0x0 2021.09.09 13:14:03 LOG5[11]: s_connect: connected 44.44.44.44:522 2021.09.09 13:14:03 LOG5[11]: Service [squid] connected remote server from 10.1.3.57:42845 2021.09.09 13:14:03 LOG6[10]: Read socket closed (readsocket) 2021.09.09 13:14:03 LOG7[11]: Setting remote socket options (FD=10) 2021.09.09 13:14:03 LOG7[11]: Option TCP_NODELAY set on remote socket 2021.09.09 13:14:03 LOG7[11]: Remote descriptor (FD=10) initialized 2021.09.09 13:14:03 LOG7[10]: Sending close_notify alert 2021.09.09 13:14:03 LOG6[11]: SNI: sending servername: 44.44.44.44 2021.09.09 13:14:03 LOG6[10]: socket fd: Broken pipe (32) 2021.09.09 13:14:03 LOG6[11]: Peer certificate not required 2021.09.09 13:14:03 LOG7[10]: TLS alert (write): warning: close notify 2021.09.09 13:14:03 LOG6[10]: SSL_shutdown successfully sent close_notify alert 2021.09.09 13:14:03 LOG6[10]: writesocket: Socket is closed 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): before SSL initialization2021.09.09 13:14:03 LOG5[10]: Connection closed: 170 byte(s) sent to TLS, 32768 byte(s) sent to socket 2021.09.09 13:14:03 LOG7[11]: Initializing application specific data for session authenticated 2021.09.09 13:14:03 LOG7[10]: Remote descriptor (FD=10) closed 2021.09.09 13:14:03 LOG7[10]: Local descriptor (FD=3) closed 2021.09.09 13:14:03 LOG7[10]: Service [squid] finished 2021.09.09 13:14:03 LOG7[ui]: Found 1 ready file descriptor(s) 2021.09.09 13:14:03 LOG7[ui]: FD=4 events=0x1 revents=0x1 2021.09.09 13:14:03 LOG7[ui]: FD=10 events=0x1 revents=0x0 2021.09.09 13:14:03 LOG7[ui]: Dispatching a signal from the signal pipe 2021.09.09 13:14:03 LOG7[ui]: Processing SIGCHLD 2021.09.09 13:14:03 LOG7[ui]: Retrieving pid statuses with waitpid() 2021.09.09 13:14:03 LOG6[ui]: Process 1937 finished with code 0 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS write client hello 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS write client hello 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS read server hello 2021.09.09 13:14:03 LOG6[11]: Certificate verification disabled 2021.09.09 13:14:03 LOG6[11]: Certificate verification disabled 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS read server certificate 2021.09.09 13:14:03 LOG6[11]: Client certificate not requested 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS read server done 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS write client key exchange 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS write change cipher spec 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS write finished 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS write finished 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS read server session ticket 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS read change cipher spec 2021.09.09 13:14:03 LOG7[11]: TLS state (connect): SSLv3/TLS read finished 2021.09.09 13:14:03 LOG7[11]: New session callback 2021.09.09 13:14:03 LOG7[11]: Peer certificate was cached (2037 bytes) 2021.09.09 13:14:03 LOG6[11]: Session id: B171BF0D4CDB808D50C3CE4CDAA6AE53F2396068A9BD947D8277294F91CCFBFE 2021.09.09 13:14:03 LOG7[11]: 1 client connect(s) requested 2021.09.09 13:14:03 LOG7[11]: 1 client connect(s) succeeded 2021.09.09 13:14:03 LOG7[11]: 0 client renegotiation(s) requested 2021.09.09 13:14:03 LOG7[11]: 0 session reuse(s) 2021.09.09 13:14:03 LOG6[11]: TLS connected: new session negotiated 2021.09.09 13:14:03 LOG6[11]: TLSv1.2 ciphersuite: AES128-GCM-SHA256 (128-bit encryption) 2021.09.09 13:14:03 LOG3[11]: SSL_get_peer_tmp_key: Peer suddenly disconnected 2021.09.09 13:14:03 LOG7[11]: Compression: null, expansion: null 2021.09.09 13:14:03 LOG6[11]: Read socket closed (readsocket) 2021.09.09 13:14:03 LOG7[11]: Sending close_notify alert 2021.09.09 13:14:03 LOG6[11]: socket fd: Broken pipe (32) 2021.09.09 13:14:03 LOG7[11]: TLS alert (write): warning: close notify 2021.09.09 13:14:03 LOG6[11]: SSL_shutdown successfully sent close_notify alert 2021.09.09 13:14:03 LOG6[11]: writesocket: Socket is closed 2021.09.09 13:14:03 LOG5[11]: Connection closed: 170 byte(s) sent to TLS, 32768 byte(s) sent to socket 2021.09.09 13:14:03 LOG7[11]: Remote descriptor (FD=10) closed 2021.09.09 13:14:03 LOG7[11]: Local descriptor (FD=3) closed 2021.09.09 13:14:03 LOG7[11]: Service [squid] finished 2021.09.09 13:14:03 LOG7[ui]: Found 1 ready file descriptor(s) 2021.09.09 13:14:03 LOG7[ui]: FD=4 events=0x1 revents=0x1 2021.09.09 13:14:03 LOG7[ui]: FD=10 events=0x1 revents=0x0 2021.09.09 13:14:03 LOG7[ui]: Dispatching a signal from the signal pipe 2021.09.09 13:14:03 LOG7[ui]: Processing SIGCHLD 2021.09.09 13:14:03 LOG7[ui]: Retrieving pid statuses with waitpid() 2021.09.09 13:14:03 LOG6[ui]: Process 1938 finished with code 0 If i test with s_client: openssl s_client -connect 44.44.44.44:522 -reconnect I see TLS reused every time. Thank you!

1 0

stunnel logfile and setuid/setgid
by Norbert Hanke 02 Sep '21

02 Sep '21

Hi, I'm new to this list and hope I don't raise a question that has been raised many times before. I searched the archive and couldn't find that discussed previously... I want to configure stunnel using setuid = nobody setgid = nobody while having it write its output to its own logfile, not using syslog, with output = /var/log/stunnel.log log = append syslog = no This works when user nobody has write-access to an existing logfile, or user nobody is allowed to create the file in the directory. Both is not a good idea: user nobody should not have write access there. I could limit potential damage by having a separate directory with such access to nobody, but that is still kind of wrong. Or I could create a separate user only for stunnel and give that user full access to a separate directory: that would be more secure, only a hijacked (hopefully not) stunnel could tamper with its own logfiles. Shouldn't stunnel create and/or open the logfile while it is still running as root, and only then switch to user nobody? Or is there an option that I did not see so far allowing for what I'm trying? Thanks for any help. Regards, Norbert

1 0

Stunnel 5.60 started via Stunnel TLS wrapper on Windows 10 machine doesn't seem to be working
by ling＠aliko.com 01 Sep '21

01 Sep '21

Hi, I am trying to get Stunnel 5.60 started automatically as a service. My stunnel.conf is stored under C:\Program Files (x86)\stunnel\config works fine if I run stunnel.exe manually from CMD or bring up the GUI and reload configuration. Now I would like it to start automatically after reboots. I tried running stunnel.exe -install which installs the Stunnel TLS wrapper service. Starting the service does not however do anything. The "Path to execute" it installs for the service is "C:\Program Files (x86)\stunnel\config" -service -install. I don't see anything in the log. I can see that the stunnel.exe process is running in task manager. But running netstat -ao shows that no port is being listened to by the PID. Tried removing my stunnel.conf file and the service will still starts but stunnel doesn't seem to be doing anything. What could be the problem?

2 2

Minor bugfix: parameter type
by Peter Pentchev 19 Aug '21

19 Aug '21

Hi, Thanks a lot for the continued development of stunnel! While checking whether my Debian packages can be built with the upcoming GCC 11, I found (or rather, GCC reported) a minor discrepancy in the type of the "hash" parameter to the crypt_DES() function in protocol.c. What do you think about the attached patch? It is also available at: https://salsa.debian.org/debian/stunnel/-/blob/master/debian/patches/06-des… Thanks again, and keep up the great work! G'luck, Peter -- Peter Pentchev roam(a)ringlet.net roam(a)debian.org pp(a)storpool.com PGP key: http://people.FreeBSD.org/~roam/roam.key.asc Key fingerprint 2EE7 A7A5 17FC 124C F115 C354 651E EFB0 2527 DF13

1 0

stunnel 60 released
by Michał Trojnara 16 Aug '21

16 Aug '21

Dear Users, I have released version 5.60 of stunnel. ### Version 5.60, 2021.08.16, urgency: LOW * New features - New 'sessionResume' service-level option to allow or disallow session resumption - Added support for the new SSL_set_options() values. - Download fresh ca-certs.pem for each new release. * Bugfixes - Fixed 'redirect' with 'protocol'. This combination is not supported by 'smtp', 'pop3' and 'imap' protocols. - Enforced minimum WIN32 log window size. - Fixed support for password-protected private keys with OpenSSL 3.0 (thx to Dmitry Belyavskiy). Home page: https://www.stunnel.org/ Download: https://www.stunnel.org/downloads.html SHA-256 hashes: c45d765b1521861fea9b03b425b9dd7d48b3055128c0aec673bba5ef9b8f787d stunnel-5.60.tar.gz 190b79cb94a4f70f362e44c32d150edf8ae660734d3fa0cbd990c3821e8f3083 stunnel-5.60-win64-installer.exe bac9bb4503cc5091d78c9deb6aa013fc07e39d67db0dfcc073b098db52f54427 stunnel-5.60-android.zip Best regards, Mike

1 0

Is it possible to tunnel all tcp sessions of docker containers
by Yichun Ding 15 Aug '21

15 Aug '21

Hi, We are looking for the possibility to encrypt all the tcp sessions of containers between hosts with stunnel. So far I had no luck to come up with an iptables rule to route the packets to stunnel running on the host. We cannot change the container code as there are too many of them. Any advice would be appreciated! -yd

1 0

stunnel ignores chroot /etc/hosts
by kmx1818＠gmail.com 10 Aug '21

10 Aug '21

Hello all! On my localhost I've got a java 1.4 tls1.0 app/service running, which is hard-coded to http-call a soap service (tls1.0 level too) running on a remote host, say, svchost. Host resolution is "files" only (ie /etc/hosts) - no dns. The aim is to make this java client tls1.2-compliant. My solution is: 1/ configure svchost to be (an alias of) localhost - in global /etc/hosts 127.0.0.1 localhost svchost 2/ configure a chroot env for stunell with its own /etc/hosts 1.2.3.4 svchost (needless to say that to make it work I had to copy /etc's nsswitch.conf resolv.conf, a bunch of libraries, esp libnsl and nsl_files etc, and create another lot of /dev entries) I've tested it with the native getent command: $ getent hosts svchost 127.0.0.1 $ chroot /var/run/stunnel/chroot getent hosts svchost 1.2.3.4 3/ run stunnel in chroot mode: # /opt/csw/bin/stunnel -version stunnel 5.59 on sparc-sun-solaris2.10 platform Compiled/running with OpenSSL 1.0.2u 20 Dec 2019 ; for tls1 clients client = yes sslVersion = TLSv1.2 delay = yes chroot = /var/run/stunnel/chroot [tls12] accept = localhost:80 connect = svchost:443 ; Alas, stunnel still resolves svchost from the global /etc/hosts - not from chroot's!: $ curl -kL http://svchost/service curl: (52) Empty reply from server ...and in /var/adm/messages: …LOG[4]: Service [tls12] accepted connection from 127.0.0.1:47944 …LOG[4]: s_connect: connecting 127.0.0.1:443 …LOG[4]: s_connect: s_poll_wait 127.0.0.1:443: waiting 10 seconds …LOG[4]: s_connect: connect 127.0.0.1:443: Connection refused (146) …LOG[4]: No more addresses to connect I've tried foreground yes/no, truss/strace - nothing useful... What am I missing!? Thank you in advance!

2 2

Unexpected socket close while sending mail
by zfefm＠gmx.de 27 Jul '21

27 Jul '21

Hi, since several days I try to get stunnel working to add TLS1.2 or higher support to my outdated email client program (Applemail 4.6) as my service provider will stop supporting the old protocols soon. The protocol of stunnel looks as if the connection gets established well. But as soon I want to send a mail my mail program tries for 10-15s to send an then gives up. In the stunnel protocol (time stamp 16:54:22) the server seems to accept the connection, but about 10-15s later I get: Unexpected socket close (s_read) Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket Any ideas what could be the problem? Thanks. conf and protocol attached. conf: setuid = nobody setgid = nogroup foreground = yes debug = 7 output = /usr/local/etc/stunnel/stunnel.log [strato-pop3] client = yes verifyChain = yes accept = 127.0.0.1:110 connect = pop3.strato.de:995 CApath = /usr/local/etc/stunnel/ cert = /usr/local/etc/stunnel/stunnel.pem checkHost = pop3.strato.de protocol = pop3 [strato-smtp] client = yes verifyChain = yes accept = 127.0.0.1:25 connect = smtp.strato.de:465 checkHost = smtp.strato.de CApath = /usr/local/etc/stunnel/ cert = /usr/local/etc/stunnel/stunnel.pem protocol = smtp protocol : 2021.07.22 16:53:49 LOG6[ui]: Initializing inetd mode configuration 2021.07.22 16:53:49 LOG7[ui]: Clients allowed=125 2021.07.22 16:53:49 LOG5[ui]: stunnel 5.59 on x86_64-apple-darwin10.8.0 platform 2021.07.22 16:53:49 LOG5[ui]: Compiled/running with OpenSSL 1.1.1k 25 Mar 2021 2021.07.22 16:53:49 LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP 2021.07.22 16:53:49 LOG7[ui]: errno: (*__error()) 2021.07.22 16:53:49 LOG6[ui]: Initializing inetd mode configuration 2021.07.22 16:53:49 LOG5[ui]: Reading configuration from file /usr/local/etc/stunnel/stunnel.conf 2021.07.22 16:53:49 LOG5[ui]: UTF-8 byte order mark detected 2021.07.22 16:53:49 LOG5[ui]: FIPS mode disabled 2021.07.22 16:53:49 LOG6[ui]: Compression enabled: 0 methods 2021.07.22 16:53:49 LOG7[ui]: No PRNG seeding was required 2021.07.22 16:53:49 LOG6[ui]: Initializing service [strato-pop3] 2021.07.22 16:53:49 LOG6[ui]: stunnel default security level set: 2 2021.07.22 16:53:49 LOG7[ui]: Ciphers: HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK 2021.07.22 16:53:49 LOG7[ui]: TLSv1.3 ciphersuites: TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256 2021.07.22 16:53:49 LOG7[ui]: TLS options: 0x02100004 (+0x00000000, -0x00000000) 2021.07.22 16:53:49 LOG6[ui]: Loading certificate from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG6[ui]: Certificate loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG6[ui]: Loading private key from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG6[ui]: Private key loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:49 LOG7[ui]: Private key check succeeded 2021.07.22 16:53:49 LOG6[ui]: DH initialization skipped: client section 2021.07.22 16:53:49 LOG7[ui]: ECDH initialization 2021.07.22 16:53:49 LOG7[ui]: ECDH initialized with curves X25519:P-256:X448:P-521:P-384 2021.07.22 16:53:49 LOG6[ui]: Initializing service [strato-smtp] 2021.07.22 16:53:50 LOG6[ui]: stunnel default security level set: 2 2021.07.22 16:53:50 LOG7[ui]: Ciphers: HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK 2021.07.22 16:53:50 LOG7[ui]: TLSv1.3 ciphersuites: TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256 2021.07.22 16:53:50 LOG7[ui]: TLS options: 0x02100004 (+0x00000000, -0x00000000) 2021.07.22 16:53:50 LOG6[ui]: Loading certificate from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG6[ui]: Certificate loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG6[ui]: Loading private key from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG6[ui]: Private key loaded from file: /usr/local/etc/stunnel/stunnel.pem 2021.07.22 16:53:50 LOG7[ui]: Private key check succeeded 2021.07.22 16:53:50 LOG6[ui]: DH initialization skipped: client section 2021.07.22 16:53:50 LOG7[ui]: ECDH initialization 2021.07.22 16:53:50 LOG7[ui]: ECDH initialized with curves X25519:P-256:X448:P-521:P-384 2021.07.22 16:53:50 LOG5[ui]: Configuration successful 2021.07.22 16:53:50 LOG7[ui]: Deallocating deployed section defaults 2021.07.22 16:53:50 LOG7[ui]: Binding service [strato-pop3] 2021.07.22 16:53:50 LOG7[ui]: Listening file descriptor created (FD=8) 2021.07.22 16:53:50 LOG7[ui]: Setting accept socket options (FD=8) 2021.07.22 16:53:50 LOG7[ui]: Option SO_REUSEADDR set on accept socket 2021.07.22 16:53:50 LOG6[ui]: Service [strato-pop3] (FD=8) bound to 127.0.0.1:110 2021.07.22 16:53:50 LOG7[ui]: Binding service [strato-smtp] 2021.07.22 16:53:50 LOG7[ui]: Listening file descriptor created (FD=10) 2021.07.22 16:53:50 LOG7[ui]: Setting accept socket options (FD=10) 2021.07.22 16:53:50 LOG7[ui]: Option SO_REUSEADDR set on accept socket 2021.07.22 16:53:50 LOG6[ui]: Service [strato-smtp] (FD=10) bound to 127.0.0.1:25 2021.07.22 16:53:50 LOG7[ui]: No pid file being created 2021.07.22 16:53:50 LOG7[cron]: Cron thread initialized 2021.07.22 16:53:50 LOG6[cron]: Executing cron jobs 2021.07.22 16:53:50 LOG6[cron]: Cron jobs completed in 0 seconds 2021.07.22 16:53:50 LOG7[cron]: Waiting 86400 seconds 2021.07.22 16:54:22 LOG7[ui]: Found 1 ready file descriptor(s) 2021.07.22 16:54:22 LOG7[ui]: FD=4 events=0x1 revents=0x0 2021.07.22 16:54:22 LOG7[ui]: FD=8 events=0x1 revents=0x1 2021.07.22 16:54:22 LOG7[ui]: FD=10 events=0x1 revents=0x0 2021.07.22 16:54:22 LOG7[ui]: Service [strato-pop3] accepted (FD=3) from 127.0.0.1:49864 2021.07.22 16:54:22 LOG7[0]: Service [strato-pop3] started 2021.07.22 16:54:22 LOG7[0]: Setting local socket options (FD=3) 2021.07.22 16:54:22 LOG7[0]: Option TCP_NODELAY set on local socket 2021.07.22 16:54:22 LOG5[0]: Service [strato-pop3] accepted connection from 127.0.0.1:49864 2021.07.22 16:54:22 LOG6[0]: s_connect: connecting 81.169.145.131:995 2021.07.22 16:54:22 LOG7[0]: s_connect: s_poll_wait 81.169.145.131:995: waiting 10 seconds 2021.07.22 16:54:22 LOG7[0]: FD=6 events=0x1 revents=0x0 2021.07.22 16:54:22 LOG7[0]: FD=13 events=0x5 revents=0x0 2021.07.22 16:54:22 LOG5[0]: s_connect: connected 81.169.145.131:995 2021.07.22 16:54:22 LOG5[0]: Service [strato-pop3] connected remote server from 192.168.17.130:49865 2021.07.22 16:54:22 LOG7[0]: Setting remote socket options (FD=13) 2021.07.22 16:54:22 LOG7[0]: Option TCP_NODELAY set on remote socket 2021.07.22 16:54:22 LOG7[0]: Remote descriptor (FD=13) initialized 2021.07.22 16:55:22 LOG3[0]: Unexpected socket close (s_read) 2021.07.22 16:55:22 LOG5[0]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket 2021.07.22 16:55:22 LOG7[0]: Remote descriptor (FD=13) closed 2021.07.22 16:55:22 LOG7[0]: Local descriptor (FD=3) closed 2021.07.22 16:55:22 LOG7[0]: Service [strato-pop3] finished (0 left) 2021.07.22 16:55:22 LOG7[0]: str_stats: 1 block(s), 32 data byte(s), 90 control byte(s) 2021.07.22 16:55:22 LOG7[0]: str_stats: 32 byte(s) at network.c:735

2 3

Equivalence of verify=2
by Yann RESCOURIO 22 Jul '21

22 Jul '21

Hello I would like to authenticate a server with only its CA file. What is the equivalence of verify=2 ? requireCert = yes verifyChain = no verifyPeer = yes Regards Yann

3 5

idea: linux stunnel mini-GUI
by Dmitry Bakshaev 13 Jul '21

13 Jul '21

we need start stunnel on linux desktop by ordinary user (like on windows): 1 click stunnel icon on system menu 2 enter user certificate password 3 use opened tunnels with users applications 4 on desktop session ends close all tunnels make XDG menu entry file: [Desktop Entry] Type=Application Name=stunnel Categories=Network; GenericName=TLS/SSL - Port Wrapper Comment[ru_RU]=Секретный туннель Icon=stunnel Exec=/usr/bin/stunnel Terminal=true X-KeepTerminal=true but only problem is how stunnel react on signals: HUP is daemon's "reload config". in X-session HUP signal is "session end" and stunnel is not exited on closing terminal or logout. attached patch change this behavior: if "foreground=yes" specified in stunnel.conf HUP signal is treated as TERM and stunnel exited. foreground=yes is "debug" or "desktop" mode of stunnel. XDG-desktop file and icon file may be included in default stunnel distributions.

1 0

Difficulty to select exact Cipher
by Sachin Deshmukh 12 Jul '21

12 Jul '21

Hello Together, I had been trying to use a stunnel to set PSK encrypted TLS. Below is my conf file. [client] client = yes accept = 127.0.0.1:8888 connect = 192.168.1.100:443 ciphers = PSK-AES128-CBC-SHA256 PSKsecrets = /data/dummy.txt I can see communication, but client e.g. Stunnel from Client side offer several other cipher in addition to exact one which is expected as per conf. I wish PSK-AES128-CBC-SHA256 (0x00ae) But I see the list below in actual communication. [image: image.png] Please let me know 1 .how we can inform stunnel to use exact and only 1 cipher provided in the conf file. Or 2. How can we state hex id instead of string. If I see a cipher list, with the same keyword as a part or whole there are more than 1 ciphers, I suppose this causes stunnel to take a list as per string match. ECDHE-PSK-AES128-CBC-SHA256 TLSv1 Kx=ECDHEPSK Au=PSK Enc=AES(128) Mac=SHA256 RSA-PSK-AES128-CBC-SHA256 TLSv1 Kx=RSAPSK Au=RSA Enc=AES(128) Mac=SHA256 DHE-PSK-AES128-CBC-SHA256 TLSv1 Kx=DHEPSK Au=PSK Enc=AES(128) Mac=SHA256 *PSK-AES128-CBC-SHA256 * TLSv1 Kx=PSK Au=PSK Enc=AES(128) Mac=SHA256 Can we make a stunnel to select only one exact cipher?

1 0

curl 7.61 exit status 8 from stunnel service of tls1
by kmx1818＠gmail.com 09 Jul '21

09 Jul '21

Hello all, For a remote tls1 web service : $ # openssl s_client -connect myremote:7002 -tls1 CONNECTED(00000004) depth=0 CN = xxx, OU = xxx, O = xxx, C = xxx verify error:num=18:self signed certificate verify return:1 depth=0 CN = xxx, OU = xxx, O = xxx, C = xxx verify return:1 --- Certificate chain ... --- Server certificate -----BEGIN CERTIFICATE----- MIIC8zCCAdsCBGCvjhEwDQYJKoZIhvcNAQEFBQAwPjEOMAwGA1UEAxMFRUZXRUIx ... QG9sNNhQW65rRVmdqy/g0cBbLKRKhmRCS+ajRIzBcO9ZmMe42TES -----END CERTIFICATE----- subject=XXX issuer=XXX --- No client certificate CA names sent --- SSL handshake has read 889 bytes and written 509 bytes --- New, TLSv1/SSLv3, Cipher is RC4-MD5 Server public key is 2048 bit Secure Renegotiation IS NOT supported Compression: NONE Expansion: NONE No ALPN negotiated SSL-Session: Protocol : TLSv1 Cipher : RC4-MD5 Session-ID: 2D9F8D8833A459C16C1D01F0C92F8EB7 Session-ID-ctx: Master-Key: 1BF68D1AAEEC291A60252ECD63C374661FBBE028FB39A75DDA29E4E3FB6FE34CFC80F875F9E16F9D7C840F185757F583 Key-Arg : None PSK identity: None PSK identity hint: None SRP username: None Start Time: 1625842735 Timeout : 7200 (sec) Verify return code: 18 (self signed certificate) --- closed $ I can test it alright with an "old" curl $ curl --version curl 7.15.4 (sparc-sun-solaris2.9) libcurl/7.15.4 OpenSSL/0.9.7g zlib/1.2.3 Protocols: tftp ftp telnet dict ldap http file https ftps Features: IPv6 Largefile NTLM SSL libz ...like this $ curl -skL https://myremote:7002/MyWebService?WSDL <?xml version="1.0" encoding="UTF-8"?> ... </soap:address> </port> </service> </definitions> I want to tls1.2-enable myremote:7002 with stunnel, and run a tls1.2 curl instead. My stunnel installation $ /opt/csw/bin/stunnel -version Initializing inetd mode configuration stunnel 5.59 on sparc-sun-solaris2.10 platform Compiled with OpenSSL 1.0.2u 20 Dec 2019 Running with OpenSSL 1.0.2o 27 Mar 2018 Threading:PTHREAD Sockets:POLL,IPv6 TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP Global options: RNDbytes = 1024 RNDfile = /dev/urandom RNDoverwrite = yes Service-level options: ciphers = HIGH:!aNULL:!SSLv2:!DH:!kDHEPSK curves = prime256v1 debug = daemon.notice logId = sequential options = NO_SSLv2 I start it with this service config: [my12] client = no accept = 7002 connect = myremote:7002 cert = /etc/opt/csw/stunnel/stunnel.crt key = /etc/opt/csw/stunnel/stunnel.key sslVersion = TLSv1.2 debug = 7 and test it with a fairly recent curl $ /opt/csw/bin/curl --version curl 7.61.0 (sparc-sun-solaris2.10) libcurl/7.61.0 OpenSSL/1.0.2o zlib/1.2.8 libidn2/2.0.4 libpsl/0.19.1 (+libidn2/2.0.4) Release-Date: 2018-07-11 Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp Features: AsynchDNS IDN IPv6 Largefile NTLM NTLM_WB SSL libz TLS-SRP UnixSockets HTTPS-proxy PSL Metalink Alas, the recent curl call $ /opt/csw/bin/curl -skL https://myremote:7002/MyWebService?WSDL ...fails with exit status 23 In verbose mode we get * Trying 127.0.0.1... * TCP_NODELAY set * Failed to set TCP_KEEPALIVE on fd 4 * Connected to localhost (127.0.0.1) port 7002 (#0) * ALPN, offering http/1.1 * Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH * successfully set certificate verify locations: * CAfile: none CApath: /etc/opt/csw/ssl/certs * TLSv1.2 (OUT), TLS header, Certificate Status (22): * TLSv1.2 (OUT), TLS handshake, Client hello (1): * TLSv1.2 (IN), TLS handshake, Server hello (2): * TLSv1.2 (IN), TLS handshake, Certificate (11): * TLSv1.2 (IN), TLS handshake, Server key exchange (12): * TLSv1.2 (IN), TLS handshake, Server finished (14): * TLSv1.2 (OUT), TLS handshake, Client key exchange (16): * TLSv1.2 (OUT), TLS change cipher, Client hello (1): * TLSv1.2 (OUT), TLS handshake, Finished (20): * TLSv1.2 (IN), TLS change cipher, Client hello (1): * TLSv1.2 (IN), TLS handshake, Finished (20): * SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384 * ALPN, server did not agree to a protocol * Server certificate: * subject: C=TS; ST=Westfarthing; L=Hobbiton; O=Thorin and Company; OU=Burglars; CN=ahost.theshire.net; emailAddress=bilbo(a)theshire.net * start date: Jun 30 09:24:25 2021 GMT * expire date: Jun 30 09:24:25 2022 GMT * issuer: C=TS; ST=Westfarthing; L=Hobbiton; O=Thorin and Company; OU=Burglars; CN=ahost.theshire.net; emailAddress=bilbo(a)theshire.net * SSL certificate verify result: self signed certificate (18), continuing anyway. > GET /MyWebService?WSDL HTTP/1.1 > Host: localhost:7002 > User-Agent: curl/7.61.0 > Accept: */* > Warning: Binary output can mess up your terminal. Use "--output -" to tell Warning: curl to output it to your terminal anyway, or consider "--output Warning: <FILE>" to save to a file. * Failed writing body (0 != 7) * Closing connection 0 * TLSv1.2 (OUT), TLS alert, Client hello (1): $ I tried various curl flags - nothing works. In the meantime stunnel logs no errors Jul 9 16:16:45 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: Service [my12] accepted connection from 127.0.0.1:39165 Jul 9 16:16:45 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: s_connect: connected 10.240.28.69:7002 Jul 9 16:16:45 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: Service [my12] connected remote server from xxx.yyy.zzz.www:39166 Jul 9 16:17:10 acuapd30 stunnel: [ID 801593 daemon.notice] LOG5[18]: Connection closed: 7 byte(s) sent to TLS, 116 byte(s) sent to socket What am i doing wrong!? Thanks in advance!

1 0

stunnel and rsyslog
by Yann RESCOURIO 28 Jun '21

28 Jun '21

Hello I use stunnel for rsyslog. And on the client equipment, I use also rsyslog queues for buffering in case of disconnection. But in case of reboot: * without stunnel, the buffered log messages are received on the rsyslog server * with stunnel, no buffered log messages are received on the rsyslog server On the client equipment, is it possible to refuse the local stunnel connections as long as the remote stunnel connection is down ? Regards Yann Rescourio

3 2

FIPS 140-2 & Ubuntu Pro
by Patrick Kaeding 23 Jun '21

23 Jun '21

Hi I am trying to set up stunnel with FIPS 140-2 compliance. I found some discussion of this on this mailing list from many years ago, but I'm not sure how much of that is still relevant today. I am running Ubuntu Pro 18.04, with FIPS mode (including the userspace modules: https://security-certs.docs.ubuntu.com/en/fips). If I simply `apt-get install stunnel4`, I can create a config with `fips = yes`, and when I start it up, I see this line logged: 2021.06.23 15:45:24 LOG5[ui]: FIPS mode enabled Does this mean I am all set, without needing to compile anything from source? In this message (from almost a decade ago), it sounds like this might be the validation I need: > BTW: "fips" option is only available when stunnel is built with FIPS support. FIPS mode is also clearly logged on startup https://www.stunnel.org/pipermail/stunnel-users/2012-November/003963.html Or do I need to build stunnel from scratch, using my local openssl distribution? Thanks! -- Patrick Kaeding pkaeding(a)launchdarkly.com

1 0

Number of tunnels open in Stunnel
by Moti Berger 21 Jun '21

21 Jun '21

Hi Is there a command I can run to get the current number of opened tunnels? I'm running Stunnel version 5.57. Thanks, Moti

1 0

Help needed for email client
by Ian Huysman 15 Jun '21

15 Jun '21

Hi, I just tried to configure stunnel as proxy between an email client (Outlook Express) and the email server (SMTP and IMAP). The problem is that the connection times out in the client while synchronising the IMAP folders. But I can send emails from the client. This is my relatively basic configuration: [SMTP] client = yes accept = 25 connect = smtp.office365.com:587 protocol = smtp [IMAP] client = yes accept = 143 connect = outlook.office365.com:993 protocol = imap Any help would be greatly appreciated! Regards, Ian.

3 2

SFTP over stunnel
by sameer_rm90＠hotmail.com 13 Jun '21

13 Jun '21

Hi, Is SFTP works over stunnel? If yes, how can configure it ?

2 1

connect with hostname obtains incorrect IP address
by stunnel＠dsbconsulting.com 11 Jun '21

11 Jun '21

Hello everyone. I'm trying to use stunnel to forward smtp traffic from an old webcam to an smtp server that requires TLS. Everything works fine if I put the IP address of the smtp server in the connect= line, but if I put the hostname there, stunnel tries to connect to a seemingly random IP address. This happens using stunnel on Windows 10 and also on my router with OpenWrt (linux) Here is the config file: [smtp] client = yes accept = 192.0.0.1:25 ;connect = 199.193.7.228:465 connect = smtp.privateemil.com:465 And here is the failing part of the stunnel log file: 2021.06.11 18:24:54 LOG5[0]: Service [smtp] accepted connection from 192.0.0.111:49334 2021.06.11 18:24:54 LOG6[0]: s_connect: connecting 47.91.170.222:465 2021.06.11 18:24:54 LOG7[0]: s_connect: s_poll_wait 47.91.170.222:465: waiting 10 seconds 2021.06.11 18:24:54 LOG7[0]: FD=6 events=0x2001 revents=0x0 2021.06.11 18:24:54 LOG7[0]: FD=10 events=0x2005 revents=0x0 2021.06.11 18:25:04 LOG3[0]: s_connect: s_poll_wait 47.91.170.222:465: TIMEOUTconnect exceeded Here is the result of ping for the smtp server: PING smtp.privateemail.com (199.193.7.228): 56 data bytes 64 bytes from 199.193.7.228: seq=0 ttl=237 time=103.059 ms

2 1

encrypted connection between application server and db server drops exactly after 300
by simona vittori 09 Jun '21

09 Jun '21

Hello, the encrypted connection between application server and db server drops exactly after 300 seconds. why? without stunnel this does not happen. we cannot understand why Thank a lot Simona

1 0

How to get high-precision timestamps in the stunnel logs
by jori.gielis＠telenetgroup.be 27 May '21

27 May '21

Hi, I want to use more accurate timestamps in the logs of stunnel. It would be nice to have milliseconds. Current format: 2021.05.27 19:00:59 LOG7[3]: Remote descriptor (FD=70) closed Needed format: 2021.05.27 19:00:59,718 LOG7[3]: Remote descriptor (FD=70) closed Is it possible to accomplish this in stunnel version 5.56? Thanks! Best regards

1 0

stunnel.pem Failure
by waynesmith philosophical-vistas.net 27 May '21

27 May '21

I preface this message to alert the reader that I remain a novice both in use of STunnel and Linux. I am trying to generate an SSL/TLS certificate for use w/ my various e-mail clients. I downloaded and extracted STunnel 5.59 on my Linux Mint Debian box. After perusing the files I issued the following command sudo ./configure --enable-fips Without repeating all the verbiage, it seemed to run properly. I then issued the following command make cert It returned the usual information requests (though it didn't ask for an e-mail address) but returned the following: /usr/bin/install -c -b -m 600 stunnel.pem /usr/local/etc/stunnel/stunnel.pem /usr/bin/install: cannot create regular file ‘/usr/local/etc/stunnel/stunnel.pem’: No such file or directory Makefile:549: recipe for target 'cert' failed make[1]: *** [cert] Error 1 make[1]: Leaving directory '/home/was/stunnel-5.59/tools' Makefile:883: recipe for target 'cert' failed make: *** [cert] Error 2 I negotiated through </usr/local/etc> and ascertained there was no </stunnel> folder. Unfortunately the permissions prevent me from creating this folder. I am thus stumped. Suggestions?

2 2

fixes for Solaris
by Pavel Heimlich 25 May '21

25 May '21

Hi, please find attached two patches that make stunnel 5.59 work better with Oracle Solaris. The first one fixes a few issues with the tests* - it removes unnecessary warning/error messages and adjusts the calls to netcat and ifconfig to what works on Solaris. The second one adds the location of 64 bit shared libraries for linking OpenSSL, similar to what has been added for Fedora. best regards P. * test result: test 010_require_cert ok test 011_verify_peer ok test 012_verify_chain ok test 013_CRL_file ok test 014_PSK_secrets ok test 015_p12_cert ok test 020_IPv6 ok test 021_FIPS skipped test 022_bind ok test 028_redirect_chain ok test 029_no_redirect_chain ok test 030_simple_execute ok test 031_redirect ok test 032_no_redirect ok test 033_redirect_exec ok test 034_no_redirect_exec ok test 035_SNI ok test 036_no_SNI ok test 037_failover_prio1 ok test 038_failover_prio2 ok test 039_failover_rr ok test 040_reload ok test 041_exec_connect ok test 042_inetd ok test 043_session_delay ok test 044_session_nodelay ok test 045_include ok test 046_resume_PSK ok test 047_resume_redirect ok test 048_resume_noredirect ok test 049_redirect_nocert ok test 050_ticket_secrets ok test 051_resume_cache_old skipped test 052_resume_cache ok test 053_resume_ticket ok test 054_resume_TLSv1_3 ok test 055_socket_close ok test 110_failure_require_cert ok test 111_failure_verify_peer ok test 112_failure_verify_chain ok test 113_failure_CRL_file ok test 114_failure_PSK_secrets ok test 115_failure_wrong_config ok test 121_failure_FIPS_ciphers skipped test 122_failure_FIPS_curves skipped summary: success 41, skip 4, fail 0 -- Pavel Heimlich | SW Developer Security Compliance & Globalization Oracle Czech s. r. o., U Trezorky 921/2, 158 00 Praha 5, Czech Republic

1 0

Stunnel stopped working..
by Alastair ＠ Expert Geeks 23 May '21

23 May '21

Hi all, I've been happily using stunnel for the same purpose and the same config for over year but it's suddenly stopped working. I was using it to wrap http shoutcast (port 8000) to https (port 8444). I'm using a letsencrypt cert. config: client = no [shoutcast] accept = 8444 connect = 127.0.0.1:8000 cert = /etc/letsencrypt/live/*server name*/fullchain.pem key = /etc/letsencrypt/live/*server name*/privkey.pem This keeps getting repeated in the log: 2021.05.22 22:18:27 LOG7[main]: Found 1 ready file descriptor(s) 2021.05.22 22:18:27 LOG7[main]: FD=4 events=0x2001 revents=0x0 2021.05.22 22:18:27 LOG7[main]: FD=9 events=0x2001 revents=0x1 2021.05.22 22:18:27 LOG7[main]: Service [shoutcast] accepted (FD=3) from *server ip*:40506 2021.05.22 22:18:27 LOG7[4]: Service [shoutcast] started 2021.05.22 22:18:27 LOG7[4]: Setting local socket options (FD=3) 2021.05.22 22:18:27 LOG7[4]: Option TCP_NODELAY set on local socket 2021.05.22 22:18:27 LOG5[4]: Service [shoutcast] accepted connection from *server ip*:40506 2021.05.22 22:18:27 LOG6[4]: Peer certificate not required 2021.05.22 22:18:27 LOG7[4]: TLS state (accept): before SSL initialization 2021.05.22 22:18:27 LOG3[4]: SSL_accept: ../ssl/record/ssl3_record.c:322: error:1408F09C:SSL routines:ssl3_get_record:http request 2021.05.22 22:18:27 LOG5[4]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket 2021.05.22 22:18:27 LOG7[4]: Local descriptor (FD=3) closed 2021.05.22 22:18:27 LOG7[4]: Service [shoutcast] finished (0 left) (server ip & server name removed) Suggestions and recommendations gratefully received! Thanks.

2 1

Re: stunnel in Citrix Environment
by Eberhard 21 May '21

21 May '21

It is pretty much impossible for users to hijack each other. The connections are persistent and if a user drops it is gone. It won’t hijack or share. Having said that, if your app works like a Web browser (not persistent) then of course they will interleave and of course you need to use the same technique as browsers – cookies, hidden fields, whatever. E VICS, LLC Eric S Eberhard 2933 W Middle Verde Rd Camp Verde, AZ 86322 928-567-3727 (land line) 928-301-7537 (cell phone) <http://www.vicsmba.com/> http://www.vicsmba.com <https://www.facebook.com/groups/286143052248115> https://www.facebook.com/groups/286143052248115 From: Bruce Liptak <bliptakjr(a)gmail.com> Sent: Friday, May 21, 2021 10:35 AM To: stunnel-users(a)stunnel.org Subject: [stunnel-users] stunnel in Citrix Environment Hello stunnel-users, Currently we have an application using stunnel being presented by a Citrix presentation server. The first user authenticates over stunnel with a PKI cert and every user thereafter creates a prompt for the first user again and again for each user that also tries to get into the app. Is there a way for stunnel to be separated based on something that pertains to the user trying to get access? We are using a PKI solution based on certificates. It's like every new user is hijacking the first users' stunnel session. Any help would be appreciated! Thank you, Bruce Liptak <mailto:[email protected]> bliptakjr(a)gmail.com CCNA R&S | VCA-DCV | Linux+ | Security+ | Network+

1 0

stunnel in Citrix Environment
by Bruce Liptak 21 May '21

21 May '21

Hello stunnel-users, Currently we have an application using stunnel being presented by a Citrix presentation server. The first user authenticates over stunnel with a PKI cert and every user thereafter creates a prompt for the first user again and again for each user that also tries to get into the app. Is there a way for stunnel to be separated based on something that pertains to the user trying to get access? We are using a PKI solution based on certificates. It's like every new user is hijacking the first users' stunnel session. Any help would be appreciated! Thank you, Bruce Liptak bliptakjr(a)gmail.com CCNA R&S | VCA-DCV | Linux+ | Security+ | Network+

1 0

Unable to connect after upgrade of server
by Christopher Schultz 13 May '21

13 May '21

All, I upgraded one of my servers from Debian stretch to Debian buster yesterday and I've been unable to establish stunnel connections to it since then. When I connect, I get this log message on the server end: LOG5[0]: Service [svn-name] accepted connection from [client ip]:45382 LOG5[0]: Certificate accepted at depth=0: [cert dn] LOG3[0]: SSL_accept: 1414D17A: error:1414D17A:SSL routines:tls12_check_peer_sigalg:wrong curve LOG5[0]: Connection reset: 0 byte(s) sent to TLS, 0 byte(s) sent to socket We are using EC certs and it's complaining about a curve. So, probably curve-related :) Our private key on the client side is using the secp256k1 curve. The client is using OpenSSL 1.0.2. The server is running OpenSSL 1.1.1. Both client and server support secp256k1. I tried specifying: curves = secp256k1 On the server side, but stunnel won't start, telling me that the configuration option isn't valid. I tried it in the global scope, and also in the service-scope and got the same error. Am I missing something? Minting new certificates (e.g. using prime256v1/secp256r1) is definitely an option, as my client openssl says it supports the NIST P-256 curve. $ openssl ecparam -list_curves secp256k1 : SECG curve over a 256 bit prime field secp384r1 : NIST/SECG curve over a 384 bit prime field secp521r1 : NIST/SECG curve over a 521 bit prime field prime256v1: X9.62/SECG curve over a 256 bit prime field That last one is NIST P-256. Is my best bet to mint a new certificate? Or is it possible to configure the server to allow this secp256k1 curve? -chris

1 0

Stunnel static compile with open ssl error while running make command
by snainwar＠rediffmail.com 30 Apr '21

30 Apr '21

I am running RHEL release v 7.9 and have successfully compiled OpenSSL version 1.1.1k using the following configuration: ##> ./config --prefix=/usr/src/openssl-1.1.1 --openssldir=/etc/openssl The following paths are shown when I run command whereis openssl # whereis openssl openssl: /usr/lib64/openssl /usr/local/bin/openssl /usr/include/openssl /opt/openssl/bin/openssl /usr/src/openssl-1.1.1k/openssl.pc ]# I have download and prepared Stunnel version 5.59 from https://www.stunnel.org/ I am using the following configuration: ##> ./configure --with-ssl=/opt/openssl --enable-static When I compile Stunnel I get the following error message when we run Make install make[2]: Nothing to be done for `install-exec-am'. /bin/mkdir -p '/usr/local/share/doc/stunnel' /bin/install -c -m 644 README.md TODO.md COPYING.md AUTHORS.md NEWS.md PORTS.md BUGS.md COPYRIGHT.md CREDITS.md INSTALL.W32.md INSTALL.WCE.md INSTALL.FIPS.md '/usr/local/share/doc/stunnel' make install-data-hook make[3]: Entering directory `/usr/src/stunnel-5.59' ********************************************************* * Type 'make cert' to also install a sample certificate * ********************************************************* make[3]: Leaving directory `/usr/src/stunnel-5.59' make[2]: Leaving directory `/usr/src/stunnel-5.59' make[1]: Leaving directory `/usr/src/stunnel-5.59' [root@tvdcltmp001 stunnel-5.59]# Looks like Stunnel cannot link (probably because it can’t find the library) Does anyone know what the error might be? What changes do I need to make to configure for compilation.

1 0

5.59 on win64
by Joe Phillips 29 Apr '21

29 Apr '21

I'm running win64 version 5.59. Installed service and it is started and running (set to automatic). But when I try to open the stunnel allUsers I get the error : stunnel server is down sue to an error, you need to exit and correct the problem. Click ok to see the error log. Shouldn't I be able to open the log window if the service is running? Also when the service is running there is no stunnel icon in the system tray. Please advise. Thanks [cid:[email protected]]

1 0

Load Balancing
by Ramin Malekgahsemi 28 Apr '21

28 Apr '21

Hi Dear friend If have one stunnel client and have three Stunnel server My question IS How by RR user three server For client ? Forward and handle connection on three server (Client and access Port is once) thanks

1 0

Stunnel static compile error while running Make command
by snainwar＠rediffmail.com 28 Apr '21

28 Apr '21

We are trying to static compile stunnel 5.59 with open ssl 1.1.1 on RHEl 6 and RHEL7 we are getting below error running command Make on the server /stunnel-5.59/src/cron.c:239: undefined reference to `BN_GENCB_new' /stunnel-5.59/src/cron.c:244: undefined reference to `BN_GENCB_set' stunnel-cron.o: In function `cron_dh_param': /stunnel-5.59/src/cron.c:219: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/cron.c:222: undefined reference to `CRYPTO_THREAD_unlock' /stunnel-5.59/src/cron.c:225: undefined reference to `CRYPTO_THREAD_read_lock' /stunnel-5.59/src/cron.c:229: undefined reference to `CRYPTO_THREAD_unlock' stunnel-cron.o: In function `cron_init': /stunnel-5.59/src/cron.c:78: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/cron.c:81: undefined reference to `CRYPTO_THREAD_unlock' stunnel-stunnel.o: In function `main_cleanup': /stunnel-5.59/src/stunnel.c:249: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/stunnel.c:263: undefined reference to `CRYPTO_THREAD_unlock' stunnel-stunnel.o: In function `process_connections': /stunnel-5.59/src/stunnel.c:889: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/stunnel.c:898: undefined reference to `CRYPTO_THREAD_unlock' stunnel-stunnel.o: In function `stunnel_info': /stunnel-5.59/src/stunnel.c:1034: undefined reference to `OpenSSL_version' /stunnel-5.59/src/stunnel.c:1036: undefined reference to `OpenSSL_version' /stunnel-5.59/src/stunnel.c:1041: undefined reference to `OpenSSL_version_num' collect2: error: ld returned 1 exit status make[2]: *** [stunnel] Error 1 make[2]: Leaving directory `/stunnel-5.59/src' make[1]: *** [all] Error 2 make[1]: Leaving directory `/stunnel-5.59/src' make: *** [all-recursive] Error 1 [root@tvdcltmp001 stunnel-5.59]#

1 0

Stunnel static compile error while running Make command
by snainwar＠rediffmail.com 28 Apr '21

28 Apr '21

We are trying to static compile stunnel 5.59 with open ssl 1.1.1 on RHEl 6 and RHEL7 we are getting below error running command Make on the server /stunnel-5.59/src/cron.c:239: undefined reference to `BN_GENCB_new' /stunnel-5.59/src/cron.c:244: undefined reference to `BN_GENCB_set' stunnel-cron.o: In function `cron_dh_param': /stunnel-5.59/src/cron.c:219: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/cron.c:222: undefined reference to `CRYPTO_THREAD_unlock' /stunnel-5.59/src/cron.c:225: undefined reference to `CRYPTO_THREAD_read_lock' /stunnel-5.59/src/cron.c:229: undefined reference to `CRYPTO_THREAD_unlock' stunnel-cron.o: In function `cron_init': /stunnel-5.59/src/cron.c:78: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/cron.c:81: undefined reference to `CRYPTO_THREAD_unlock' stunnel-stunnel.o: In function `main_cleanup': /stunnel-5.59/src/stunnel.c:249: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/stunnel.c:263: undefined reference to `CRYPTO_THREAD_unlock' stunnel-stunnel.o: In function `process_connections': /stunnel-5.59/src/stunnel.c:889: undefined reference to `CRYPTO_THREAD_write_lock' /stunnel-5.59/src/stunnel.c:898: undefined reference to `CRYPTO_THREAD_unlock' stunnel-stunnel.o: In function `stunnel_info': /stunnel-5.59/src/stunnel.c:1034: undefined reference to `OpenSSL_version' /stunnel-5.59/src/stunnel.c:1036: undefined reference to `OpenSSL_version' /stunnel-5.59/src/stunnel.c:1041: undefined reference to `OpenSSL_version_num' collect2: error: ld returned 1 exit status make[2]: *** [stunnel] Error 1 make[2]: Leaving directory `/stunnel-5.59/src' make[1]: *** [all] Error 2 make[1]: Leaving directory `/stunnel-5.59/src' make: *** [all-recursive] Error 1 [root@tvdcltmp001 stunnel-5.59]#

1 0

Unable to reload Stunnel in Linux
by gorf＠hyperfunk.club 27 Apr '21

27 Apr '21

Hi, Normally, I would call "kill -HUP" with Stunnel's process ID to make it reload the configuration in Linux. I was very surprised when I tried that and the process stopped. Why would HUP cause it to exit, rather than reload the config? It doesn't do that on every machine. Thanks.

2 4

Questions about two host connection using stunnel
by yfmao＠seas.upenn.edu 24 Apr '21

24 Apr '21

I am using stunnel4 to build a secure connection between two ubuntu hosts. One of the hosts (sender) will send "hello world" to another host (receiver). When I am using tcpdump in receiver to capture the packets sending from sender, I find out that one of the packets contains "hello world" in plaintext. From my understanding, stunnel will encrypt the content of "hello world" if everything is correct, so I shouldn't be able to see "hello world" in plaintext among any incoming packets. Any ideas about what is going wrong here? Here I will put my stunnel.config for your reference: cert = /home/ubuntu/client_server/stunnel.pem key = /home/ubuntu/client_server/stunnel.key debug = 7 output = /home/ubuntu/client_server/stunnel.log socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 options = ALL [services] accept = 6667 connect = some_ip_address:6666 TIMEOUTclose = 0

4 6

Paid work
by David Rose (dsr) 24 Apr '21

24 Apr '21

I need an Stunnel config that will allow my Windows app that only can send SMTP without any authentication or encryption to be able to send email via Gmail or Office 365. Is this something that someone would be able to write for me and if so, what would you charge ? Thanks David --

3 2

Does stunnel support OCSP stapling?
by koalabearguo＠gmail.com 24 Apr '21

24 Apr '21

Will it plan to support in the future? Thanks.

3 2

Re: Fwd: Re: Local socket keeps listening
by Eberhard 16 Apr '21

16 Apr '21

I’ll toss in an unpopular opinion here. I have used stunnel since day one. I had over the years problems with it not answering or the parent process dying altogether and other issues. I finally decided to run it from inetd rather than as a service. It is logical that this is a little slower but with modern machines I don’t notice it. inetd always is running. Always. If it is not you pretty much cannot use the machine. It has been a service program forever and is dead reliable. What you get is total reliability for an unnoticeable loss of speed. I suppose a heavily loaded machine running at capacity might not like this – my answer is throw hardware at it. I need reliable more than anything else. I’d at least try it! E VICS, LLC Eric S Eberhard 2933 W Middle Verde Rd Camp Verde, AZ 86322 928-567-3727 (land line) 928-301-7537 (cell phone) <http://www.vicsmba.com/> http://www.vicsmba.com <https://www.facebook.com/groups/286143052248115> https://www.facebook.com/groups/286143052248115 From: Jorge Redondo Flames <jorge.redondo(a)gmail.com> Sent: Wednesday, April 14, 2021 11:49 AM To: Peter Pentchev <roam(a)ringlet.net> Cc: stunnel-users(a)stunnel.org Subject: [stunnel-users] Re: Fwd: Re: Local socket keeps listening Got it. Thank you very much! On Wed, 14 Apr 2021 at 20:41, Peter Pentchev <roam(a)ringlet.net <mailto:[email protected]> > wrote: On Wed, Apr 14, 2021 at 08:24:51PM +0200, Jorge Redondo Flames wrote: > On Wed, 14 Apr 2021 at 20:19, Jochen Bern <Jochen.Bern(a)binect.de <mailto:[email protected]> > wrote: > > On 14.04.21 19:58, Jorge Redondo Flames wrote: > > > Stunnel could listen on its local port *only* when the peer server is > > > listening on its corresponding server socket. So if there is no serve on > > > the other side, there should not be local listening socket. Does not that > > > make sense? > > > > No. > > > > In the general situation (server *not* being on the same machine as > > stunnel), stunnel CANNOT know whether the server's listening short of > > trying to connect to it - which it will only do on behalf of an incoming > > client request, which would never happen if stunnel weren't listening. > > > > Even if server and stunnel run on the same machine/OS, finding out about > > the server's state would require a bunch of special-purpose code. > > > > Assuming that they *are* on a common Linux (or at least unixoid) system, > > however, it would be rather trivial to write a root cron job that checks > > the output of "ss"/"netstat" for the server's LISTEN and simply > > terminates stunnel if it isn't found. > > > > Or even better, have the server *restarted* automatically whenever it > > croaks ... > > Understood. Although it still seems to me that the code doing more or less > what the cron job would do might worth. So, three points here. 1. There are some services (some servers) that do not react very nicely to somebody connecting to them and disconnecting immediately. Some of them do some work at the moment of the connection (e.g. resolve the client's IP address, check it against firewall rules, or even do some actual, service-specific, work, e.g. allocate buffers, prepare some kind of data...). Some of them are configured in such ways as to avoid portscanners or denial of service attacks or spam or flood or... many other things. In general, unless you *know* that it is safe to connect and immediately disconnect from the remote service, it is very unwise to try to do that. In your particular case, you know that, but in general, it is not a good idea. 2. Even if stunnel would try to connect to the remote service, what happens if the connection fails? OK, you say stunnel should close its local listening socket, but what then - will it never open it again? And if here's the part when you say "it can try to connect to the remote server again and start listening again" - okay, how much time passes between these connection attempts? Even something like a second may be bad if a real client chooses exactly this second to try to connect to stunnel and... stunnel is not listening... even though the remote server has started listening immediately after stunnel's last unsuccessful attempt. So... whatever interval you pick, closing the local listening socket *will* result in real, live clients failing to connect. 3. A more general point: if you really want to check whether a service is operational, only checking whether it will accept a connection is not enough. I've seen *many* failure modes over the years: from an overloaded machine where the OS kernel will accept the connection, but none of the actual server processes will react, through an overloaded service process that accepts the connection but spends too much time processing other requests to pay any attention to it, to a firewall host gone crazy that will pass connection packets, but will then refuse to pass the actual payload (yes, I've seen that happen for at least three different reasons). So an actual service check would be to connect and then send some kind of simple request to the server that you know will not take it too much time and resources to process, but will give you some measure of confidence that the server is actually serving requests and data. But in short, it is impossible for stunnel to know whether a remote server is listening for a connection without trying to connect, it may not be "polite" for it to try to connect too often, and trying to connect not-too-often *will* result in real clients being unable to connect in the intermediate intervals. G'luck, Peter -- Peter Pentchev roam(a)ringlet.net <mailto:[email protected]> roam(a)debian.org <mailto:[email protected]> pp(a)storpool.com <mailto:[email protected]> PGP key: http://people.FreeBSD.org/~roam/roam.key.asc Key fingerprint 2EE7 A7A5 17FC 124C F115 C354 651E EFB0 2527 DF13

2 3

Fwd: Re: Local socket keeps listening
by Jorge Redondo Flames 14 Apr '21

14 Apr '21

---------- Forwarded message --------- From: Jorge Redondo Flames <jorge.redondo(a)gmail.com> Date: Wed, 14 Apr 2021 at 19:45 Subject: Re: [stunnel-users] Re: Local socket keeps listening To: Ludolf Holzheid <lholzheid(a)bihl-wiedemann.de> Stunnel could listen on its local port *only* when the peer server is listening on its corresponding server socket. So if there is no serve on the other side, there should not be local listening socket. Does not that make sense? On Wed, 14 Apr 2021 at 19:38, Ludolf Holzheid <lholzheid(a)bihl-wiedemann.de> wrote: > On Wed, 2021-04-14 19:13:03 +0200, Jorge Redondo Flames wrote: > > [..] > > > > Is there a way to configure Stunnel to *close* the local socket (not > > listening anymore) whenever the peer process (i.e. the server) has closed > > its socket? > > Stunnel listens for connection request from the client(s) and connects > to the server on behalf of the client(s). How will a client ever be > able to connect through Stunnel again if Stunnel closes the listening > socket? > > Ludolf > > -- > > Ludolf Holzheid > > Bihl+Wiedemann GmbH > Floßwörthstraße 41 > 68199 Mannheim, Germany > > Tel: +49 621 33996-0 > Fax: +49 621 3392239 > > mailto:[email protected] > https://www.bihl-wiedemann.de > > Sitz der Gesellschaft: Mannheim > Geschäftsführer: Jochen Bihl, Bernhard Wiedemann > Amtsgericht Mannheim, HRB 5796 > > Datenschutzerklärung: https://www.bihl-wiedemann.de/de/meta/datenschutz > _______________________________________________ > stunnel-users mailing list -- stunnel-users(a)stunnel.org > To unsubscribe send an email to stunnel-users-leave(a)stunnel.org >

3 4

Re: Local socket keeps listening
by Ludolf Holzheid 14 Apr '21

14 Apr '21

On Wed, 2021-04-14 19:45:06 +0200, Jorge Redondo Flames wrote: > Stunnel could listen on its local port *only* when the peer server is > listening on its corresponding server socket. So if there is no serve on > the other side, there should not be local listening socket. Does not that > make sense? Stunnel connects to the server only when a client connects to Stunnel. If Stunnel is not listening for clients, it does not try to connect to the server. If it does not try to connect to the server, it does not know if the server is listening. Ludolf > On Wed, 14 Apr 2021 at 19:38, Ludolf Holzheid <lholzheid(a)bihl-wiedemann.de> > wrote: > > > On Wed, 2021-04-14 19:13:03 +0200, Jorge Redondo Flames wrote: > > > [..] > > > > > > Is there a way to configure Stunnel to *close* the local socket (not > > > listening anymore) whenever the peer process (i.e. the server) has closed > > > its socket? > > > > Stunnel listens for connection request from the client(s) and connects > > to the server on behalf of the client(s). How will a client ever be > > able to connect through Stunnel again if Stunnel closes the listening > > socket? > > > > Ludolf -- Ludolf Holzheid Bihl+Wiedemann GmbH Floßwörthstraße 41 68199 Mannheim, Germany Tel: +49 621 33996-0 Fax: +49 621 3392239 mailto:[email protected] https://www.bihl-wiedemann.de Sitz der Gesellschaft: Mannheim Geschäftsführer: Jochen Bihl, Bernhard Wiedemann Amtsgericht Mannheim, HRB 5796 Datenschutzerklärung: https://www.bihl-wiedemann.de/de/meta/datenschutz

2 1

Local socket keeps listening
by Jorge Redondo Flames 14 Apr '21

14 Apr '21

Hey there, thanks for being there. I have a Client/Server services originally communicating over TCP. The client periodically monitors the socket connection by reading from the socket and, in the case the connection has been lost, the client retries the connection a given amount of times, after which it realizes that the server is definitely down. Now I have implemented secure communication using Stunnel and everything works fine except for the fact that, whenever the server process crashes (which is eventually expected), the client is no longer able to successfully monitor the connection as expected since, no matter what happens to the server process, the local Stunnel daemon keeps listening on its local socket. So, when the client retries connection, it successfully connects to the local socket. Although it soon receives connection reset, this successful connection attempt happening even when the server process is actually down completely breaks the client logic. I could change this logic but I really would like to avoid that path. So here is my question: Is there a way to configure Stunnel to *close* the local socket (not listening anymore) whenever the peer process (i.e. the server) has closed its socket? Thank you very much in advance.

2 1

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

stunnel-users