This is a contradiction on how to differentiate V1 and V2 handshake. It's confusing if someone wants to implement his own version of Tor (JTor, silvertunnel,...). [tor-spec](https://gitweb.torproject.org/torspec.git/blob/master:/tor-spec.txt) (and [130-v2-conn-protocol](https://gitweb.torproject.org/torspec.git/blob?f=proposals/130-v2-conn-protocol.txt)): ``` In "certificates up-front" (a.k.a "the v1 handshake"), [...] The initiator's ClientHello MUST NOT include any ciphersuites other than: TLS_DHE_RSA_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_128_CBC_SHA SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA ``` The actual implementation: ``` /* Now we need to see if there are any ciphers whose presence means we're * dealing with an updated Tor. */ for (i = 0; i < sk_SSL_CIPHER_num(session->ciphers); ++i) { SSL_CIPHER *cipher = sk_SSL_CIPHER_value(session->ciphers, i); const char *ciphername = SSL_CIPHER_get_name(cipher); if (strcmp(ciphername, TLS1_TXT_DHE_RSA_WITH_AES_128_SHA) && strcmp(ciphername, TLS1_TXT_DHE_RSA_WITH_AES_256_SHA) && strcmp(ciphername, SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA) && strcmp(ciphername, "(NONE)")) { log_debug(LD_NET, "Got a non-version-1 cipher called '%s'", ciphername); // return 1; goto dump_list; } } ``` So, in practice, the use of the SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA (SSL3_TXT_EDH_DSS_DES_192_CBC3_SHA) cipher suite is considered as a sign of the use of the V2 handshake. This contradicts all specifications. (According to [124-tls-certificates](https://gitweb.torproject.org/torspec.git/blob?f=proposals/124-tls-certificates.txt) and tor.git history, two of these cipher suites {AES_256 and DSS} have never been used in Tor v0/1, they seem to be include for better censorship resistance). **Trac**: **Username**: cced