- stunnel-users - stunnel.org

Error resolving '...' (Windows)
by Oliver Ackermann (infowing AG) 03 Aug '05

03 Aug '05

On a Windows 2000 machine I always get the following error when I try to start stunnel (4.11): Error resolving 'x.y.z.23': Neither nodename nor servname known (EAI_NONAME) The client should connect to a server using SSL. x.y.z.23 is a static IP address of the client. The client has multiple IP addresses and stunnel should use this one to connect to the server. Contents of stunnel.conf: client=yes [service] local=x.y.z.23 accept=12345 connect=server:12345 Why does stunnel try to "resolve" this IP? Is the configuration correct? Thanks for your help! Oliver

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ftp support for stunnel-4.11 (still has errors, do not know why)
by ZHUANG YUYAO 03 Aug '05

03 Aug '05

hi, here is the initial patch (pre-pre-pre-alpha! just a demo/test) for adding ftp support to stunnel-4.11. Known bugs: 1) only tested under linux. debian 3.1 (testing), gcc version 3.3.5 (Debian 1:3.3.5-13) 2) ftp_alloc_port() in ftp.c is not yet finished. just a demo; 3) only works when configured with --with-threads=ucontext. does not work with --with-threads=pthread! 4) libwrap support is not tested. 5) only tested with flashfxp (3.0.2 build(1043) implicit SSL); 6) still contains memory leaks. 7) can only successfully transfer(RETR) small files whose size is less than about 90K bytes. stunnel hangs while transferring a larger file, looks like poll() in scan_waiting_queue() (network.c line 164) can not receive a POLLOUT event from ssl_wfd->fd after successfully transfered 90K bytes. the log file is also included in this mail. bug #7 really frustrats me. still do not know why. could anyone please give me some hints? Zhuang Yuyao.

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some thoughts of add ftp server proxy support to stunnel4. comments required
by ZHUANG YUYAO 30 Jul '05

30 Jul '05

Hi, I am thinking about adding ftp protocol support to stunnel4. first, some restrictions to simplify the implimentation: 1) only support for stunnel running in server mode, users can use ftp clients which support ssl connection (ie. FlashFXP) to connect to the real ftp server through stunnel daemon; 2) only support standalone service mode of stunnel. (inted support may be added later, I've just read the source code related to standalone service, and have not got any clue about how to support inetd.) 3) only support FTP implicit SSL and PASSIVE mode; the code may look like this: (the real ftp server is at 192.168.10.254, listening on port 21.) 1) start a stunnel daemon nonmally with accept = 990, remote = 192.168.10.254:21, protocol = ftp; 2) when a connection come in, parse the ftp server response, search for "227 Entering Passive Mode (192,168,10,254,133,22)", then got the data connection IP: 192.168.10.254 PORT: 34070; 3) plus 1 to the data connction port 34070, then we got 34071 which will be used as stunnel accept port; 4) create a LOCAL_OPTIONS structure instance opt (prototypes.h) dynamically, set opt->accept=1, opt->local_addr same to the parent stunnel, change its port to 34071, opt->remote_addr = real data connection (IP: 192.168.10.254 PORT: 34070); opt->fd = socket(), bind(); 5) set local_option->next = opt; 6) s_poll_add (&fds, opt->fd, 1, 0); (stunnel.c) (the local variable fds needs to be changed to a global variable, by the way, I think it is also required if stunnel want real SIGHUP configuration-on-the-fly support) 7) changed server response to "227 Entering Passive Mode (STUNNEL_LOCAL_HOST,133,23)", then send back to client. 8) the client will then connect to STUNNEL_LOCAL_HOST port = 34071, negotiate SSL session and send/receive data; 9) after ftp session finished (How to know a ftp session is finished?), free the dynamic LOCAL_OPTIONS opt, remove opt->fd from fds, close the data sessoin. There are only two source file (stunnel.c, protocol.c) need to be modified to implement these functions. Any suggestions will be appreciated. Thank you. Zhuang Yuyao 2005/7/28

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Configuration and startup?
by JACK ROBERT BIESIADECKI 29 Jul '05

29 Jul '05

Hi, I am new to stunnel and Linux. I am trying to set up a secure connection to a server which can be accessed from any web browser on a designated port. I need to be able to access a web browser server administration interface, this is over http, I need to make this an https connection. I have compiled and installed stunnel on a Linux machine (FC4) but can't seem to get any response from it or make it work. If anyone can explain, step by step, how to configure stunnel for general https usage, it would be greatly appreciated. I have looked through the documentation but I have not been able to get it to work. I have also noticed that webmin supports stunnel but there is nothing in it. I added this to the conf file: [https] accept = 8080 connect = 28477 TIMEOUTclose = 0 Thanks

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3.x branch updates
by Brian Hatch 29 Jul '05

29 Jul '05

As y'all can probably see, I've started climbing out from the rock under which I've been living (the rock called "too many kids".) If there are folks who have issues or bugs in stunnel 3.x, let's get talking off list so we can make another release. I'd like to include only security or bug fixes. The 4.x branch is totally fine, and I see no reason to add new features to the 3.x branch. This would be one of at most a few last bug fix releases for the 3.x branch so I can lay it to rest. -- Brian Hatch "Look, somebody's got to have Systems and some damn perspective around Security Engineer here. Boom, sooner or later. http://www.ifokr.org/bri/ *BOOM*!" Every message PGP signed

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Linux pppd VPN network notwork very well
by Colin McKinnon 27 Jul '05

27 Jul '05

Hi all, I've got two two LANs behind masquerading routers that I've linked via a stunnel + pppd vpn. When it works, it works, but I've got a couple of problems - has anybody out there in Stunnel Land managed to fix / workaround these? 1) The connection goes down fairly regluarly. I've setup a cron job to move a few packets back and forth to make sure that the ADSL connection at both ends stays up (pppd set not do demand stuff). There's nothing in the logs to suggest that the ADSL *is* going down, but I thought it would eliminate a lot of possibilities. (see log entries below). Currently the link is going down at lesat once per day. Uptime varies greatly. I can't see anyway of asking stunnel to try again if the pppd exits (see conf below) other than manually restarting it. I'm hoping to scale the VPN up to multiple sites - with one connection, I can just do /etc/rc.d/stunnel restart - but if I've got multiple instances of stunnel running with different configs it gets a bit messy to reset a single connection. I did think about having multiple hard links to the stunnel binary, so each VPN will have a different process name attached to it, but this strikes me as a bit of a hack. 2) bandwidth on the link is poor. I consistently get 1/4 of the bandwidth (measured using scp to copy largish files) compared with bypassing the stunnel/pppd pair (same route between LANs). While I expected some overhead, this seems rather a lot. 3) latency is a lot higher too 4) The VPN seems to stutter more regularly than the direct connection ...I mean that I don't seem to be getting any traffic for 5-10 seconds then it resumes without any loss of data (e.g. when using ssh). The routers at either end are relatively dumb so (as I understand it) there's not many options for using IPIP or GRE tunnelling). Anybody got any suggestions as to how I can make it (particularly) more reliable and (also) a bit faster? TIA, Colin McKinnon pppd -------- pppd local nodeflate nobsdcomp nodefaultroute 10.1.17.208:10.1.20.202 log entries: ---------------- Stunnel started manually: Jul 19 08:25:59 serv8 stunnel[740]: stunnel 4.05 on i686-suse-linux-gnu PTHREAD with OpenSSL 0.9.7d 17 Mar 2004 Jul 19 08:25:59 serv8 stunnel[740]: FD_SETSIZE=1024, file ulimit=1024 -> 500 clients allowed Jul 19 08:25:59 serv8 pppd[743]: pppd 2.4.2 started by stunnel, uid 100 Jul 19 08:25:59 serv8 pppd[743]: Using interface ppp0 Jul 19 08:25:59 serv8 pppd[743]: Connect: ppp0 <--> /dev/pts/1 Everything works fine (although a little slow) then... Jul 19 10:36:32 serv8 pppd[743]: No response to 4 echo-requests Jul 19 10:36:32 serv8 pppd[743]: Serial link appears to be disconnected. Jul 19 10:36:34 serv8 pppd[743]: Script /etc/ppp/ip-down finished (pid 1668), status = 0x0 Jul 19 10:36:34 serv8 ip-down: SIOCDELRT: No such process Jul 19 10:36:36 serv8 pppd[743]: Connection terminated. Jul 19 10:36:36 serv8 pppd[743]: Connect time 130.6 minutes. Jul 19 10:36:36 serv8 pppd[743]: Sent 58200 bytes, received 57227 bytes. Jul 19 10:36:36 serv8 pppd[743]: Connect time 130.6 minutes. Jul 19 10:36:36 serv8 pppd[743]: Sent 58200 bytes, received 57227 bytes. Jul 19 10:36:36 serv8 pppd[743]: Exit. Jul 19 10:36:36 serv8 stunnel[741]: readsocket: Input/output error (5) Jul 19 10:36:36 serv8 stunnel[741]: Connection reset: 68626 bytes sent to SSL, 66280 bytes sent to socket Stunnel config --------------------- foreground = no client = yes setuid = stunnel setgid = dialout CAfile = /etc/stunnel/3bCArootCert.pem cert = /etc/stunnel/system.pem verify = 2 session = 3600 [ppp] connect = remotehost:2020 exec = /usr/sbin/pppd execargs = pppd local nodeflate nobsdcomp nodefaultroute 10.1.17.208:10.1.20.202 pty = yes (converse at other end) Routing at 'cleint' end --------------------------------- Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.1.20.202 * 255.255.255.255 UH 0 0 0 ppp0 192.168.1.0 * 255.255.255.0 U 0 0 0 eth1 10.1.20.0 * 255.255.255.0 U 0 0 0 ppp0 10.1.17.0 * 255.255.255.0 U 0 0 0 eth2 loopback * 255.0.0.0 U 0 0 0 lo default 192.168.1.1 0.0.0.0 UG 0 0 0 eth1 (eth1 conects to the ADSL router, eth2 to the LAN)

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newbie q: stunnel -d and -r options
by Jagannadha Bhattu 27 Jul '05

27 Jul '05

I was reading a book where they discussed using stunnel as client and server proxy with -d -r and -c options. I have SuSE 9.3 and the stunnel on it has different options. Then I found that we have to use config file. I used it to configure my server. I defined the following section: [myserver] accept = 12345 connect = 12323 Here my server listens on 12323. I have my server already running. Now I typed stunnel and nothing happened. I typed "pgrep stunnel" and could not see anything. Apparently I have not understood how stunnel works. Can some one let me know how can I configure to use stunnel to secure my server app and my client app which are not ssl aware. I also have a question. The book which I am reading says, stunnel acts as a proxy for a server app. If my server app is listening on A then if I want stunnel to service all clients connecting to A then how can it do it as that port is already serviced by my server app. Thanks JB

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error compilation stunnel-4.11 for ARM9
by Stage Iup - Fabrice & Frederic 27 Jul '05

27 Jul '05

Hi all, I would like to compile stunnel-4.11for a board based on a ATMEL at91rm9200. I try to compile this with this commande [root@StageIup stunnel-4.11]# CC=/usr/local/arm/3.0/bin/arm-linux-gcc ./configure --host=arm-linux --prefix=/home/fabrice/dev/stunnel/stunnel-armtest --with-ssl=/home/fabrice/dev/openssl But I have the following error configure: **************************************** PTY device files checking for "/dev/ptmx"... configure: error: cannot check for file existence when cross compiling If any body have an idea about how to resolve this problem or how to compile stunnel for ARM ... Thanks -- Cordialement Fabrice -- IFOTEC Tél : 04 76 67 53 53

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samba over stunnel performance
by Brian Szymanski 27 Jul '05

27 Jul '05

Howdy... I'm trying to run samba over stunnel on a wireless connection. Here's the setup: unix box <- wifi -> windows laptop Unfortunately, reading files from the shared drive is extremely slow. If I look at the stunnel box on my windows machine, it is pumping out about 20 messages/second that say: LOG7[2140:3636]: SSL_read returned WANT_READ: retrying On two >1GHz machines, this is utilizing about 5% of cpu, and 4% of the 11Mbps link. Clearly there is room for improvement here! I tried poking around with stunnel.conf on the server to no avail - specifically, I commented out the lines: ; Some performance tunings socket = l:TCP_NODELAY=1 socket = r:TCP_NODELAY=1 ;compression = rle And restarted stunnel - same miserable performance (roughly the same throughput, and resource usage). Is there something about the SMB protocol that would cause stunnel to not deal with it well? If so, is there a configuration option somewhere I can tune, or do I have to RTFS & hack it to get decent performance here? Any tips would be greatly appreciated. Thanks in advance! Cheers, Brian Brian Szymanski Software and Systems Developer Media Matters for America ski(a)mediamatters.org aim: xbrianskix

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zlib + win2000 = crash
by lascjr＠bol.com.br 27 Jul '05

27 Jul '05

Hi, I successfully installed and executed stunnel without compression and with compression RLE, but with compression ZLIB I receive the following message in the startup: 2005.07.25 08:24:28 LOG5[1408:1524]: stunnel 4.11 on x86-pc-mingw32-gnu WIN32+IPv4 with OpenSSL 0.9.7f 22 Mar 2005 2005.07.25 08:24:28 LOG3[1408:1976]: Error reading certificate file: stunnel.pem 2005.07.25 08:24:28 LOG3[1408:1976]: error stack: 25070067 : error:25070067:DSO support routines:DSO_load:could not load the shared library 2005.07.25 08:24:28 LOG3[1408:1976]: error stack: 25078067 : error:25078067:DSO support routines:WIN32_LOAD:could not load the shared library 2005.07.25 08:24:28 LOG3[1408:1976]: error stack: 25070067 : error:25070067:DSO support routines:DSO_load:could not load the shared library 2005.07.25 08:24:28 LOG3[1408:1976]: SSL_CTX_use_certificate_chain_file: 25078067: error:25078067:DSO support routines:WIN32_LOAD:could not load the shared library 2005.07.25 08:24:28 LOG3[1408:1976]: Server is down I made download of archive ZLIB1.DLL in the client and in the server, the startup is normal, but after the beginning of the communications the server crash. I use Win2000 Server SP4 in the server and Win2000 Pro in the client. thanks Luis A S C Junior

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