[stunnel-users] Ubuntu 16.04 problem

Carter Browne cbcs at comcast.net
Tue Nov 14 21:10:05 CET 2017

I have a very confusing problem with stunnel on Ubuntu.  I have a 
configuration file that I have used in both Windows and Arch Linux.  In 
the Arch version, I use a single file with all the certificates for the 
partner systems, in the Windows version I use a capath directory.  I 
have tried both here and I always get the response "tlsv1 alert unknown ca".

The beginning of the stunnel.conf file is below.  Any hints would be 


cert = /etc/stunnel/xxxxxxx.pem
key = /etc/stunnel/xxxxxxx.pem

fips = no

# Enable client mode
client = yes

; Some security enhancements for UNIX systems - comment them out on Win32
#chroot = /var/run/stunnel/
#setuid = stunnel
#setgid = stunnel
; PID is created inside chroot jail
pid = /etc/stunnel/stunnel.pid

; Some performance tunings
# Debug and Foreground are for testing
socket = l:TCP_NODELAY=1
socket = r:TCP_NODELAY=1
# Uncomment for debugging stunnel problems
debug = 5
output = /etc/stunnel/stunnel.log
##foreground = yes

; NO SSLv2
options = NO_SSLv3
sslVersion = all

Ciphers = 

# Uncomment and modify the CAFile to point to your ca.txt file
#CAFile = /etc/stunnel/all.pem

CAPath = /etc/stunnel/capath
#CAPath = @sysconfdir/ssl/certs

# Uncomment and modify the verify to enable CA validation
verifyChain = no
VerifyPeer = yes

More information about the stunnel-users mailing list