GoAhead TLS flaws allow revoked client certificates and enable session decryption

In affected GoAhead configurations, the OpenSSL TLS backend loaded a certificate revocation list but did not enable revocation checking. As a result, a revoked client certificate could pass mutual-TLS authentication. Two additional TLS problems affect specific Mbed TLS and older LibreSSL builds. As of October 27, the source reported no known use of these problems in attacks, although this does not prove that none occurred.