Thanks for the feedback. There was a bug in mIRC v6.35 that caused it to incorrectly validate the certificate in some situations. The method was changed in v7.x, however it looks like the validation is still not being performed correctly.
I have made another change that seems to resolve this issue. Now, when I try to connect to chat.freenode.net:+7000, mIRC will report:
"unable to get local issuer certificate"
"the security certificate date is valid"
"The security certificate has a valid name matching the name of the server."
This seems to be correct, since mIRC cannot validate the certificate without a Trusted Authorities file.
If I then open the mIRC Options->Connect->Options->SSL dialog and load UTN-USERFirst-Hardware.pem (exported from the Windows certificates dialog and converted from DER to PEM format) as the Trusted Authorities file and then connect again to the server, mIRC does not display the warning dialog and connects without any issues, indicating that it was able to validate the certificate.
This change should be in the next version.
