Hi Guys, To me this looks like a cipher issue. There are a few options that you can try to resolve this if it is.
I would try adding the following lines into your STunnel Configuration file:
delay = yes options = NO_SSLv2 options = NO_SSLv3 options = NO_TLSv1 options = CIPHER_SERVER_PREFERENCE options = DONT_INSERT_EMPTY_FRAGMENTS
Delay will delay and DNS lookups that maybe actioned by the request (not normally needed but I always include if for sanity sake) The three 'options' sections turn off all the known problematic cipher lists if you need a key that is in one of these block feel free to remove that directive but I think a good start would be to leave the 'NO_SSLv3' option in place The 'CIPHER_SERVER_PREFERENCE' option will make set whether the client is allowed to renegotiat the ciphers that are to be used between the client and the server process. And finally 'DONT_INSERT_EMPTY_FRAGMENTS' will mitigate an issue in the CBC ciphers that was in the SSLv3 and TLS1.0 cipher lists again I only include it for sanity sake now but its better to have than to go without.
Hi Scott,
Thanks for the message. I tried this but to no avail. If I use that verbatim I get the error: 2016.09.21 06:46:46 LOG3[ui]: SSL_connect: 140740BF: error:140740BF:SSL routines:SSL23_CLIENT_HELLO:no protocols available In fact it seems like the only security protocol available to me is TLSv1, as the presence of the NO_SSLv2 and NO_SSLv3 options have no effect (which makes sense: I understand that Stunnel doesn’t use SSL v2 or v3 these days). I don’t know if this indicates something untoward..
Best, Dave.
On 21 Sep 2016, at 03:15, Scott McKeown [email protected] wrote:
Hi Guys, To me this looks like a cipher issue. There are a few options that you can try to resolve this if it is.
I would try adding the following lines into your STunnel Configuration file:
delay = yes options = NO_SSLv2 options = NO_SSLv3 options = NO_TLSv1 options = CIPHER_SERVER_PREFERENCE options = DONT_INSERT_EMPTY_FRAGMENTS
Delay will delay and DNS lookups that maybe actioned by the request (not normally needed but I always include if for sanity sake) The three 'options' sections turn off all the known problematic cipher lists if you need a key that is in one of these block feel free to remove that directive but I think a good start would be to leave the 'NO_SSLv3' option in place The 'CIPHER_SERVER_PREFERENCE' option will make set whether the client is allowed to renegotiat the ciphers that are to be used between the client and the server process. And finally 'DONT_INSERT_EMPTY_FRAGMENTS' will mitigate an issue in the CBC ciphers that was in the SSLv3 and TLS1.0 cipher lists again I only include it for sanity sake now but its better to have than to go without.
-
Dave Gradwell -
Scott McKeown