Hi Alex, if you configure s_client with the same list of ciphersuites that firefox sends, then s_server will show the same reaction. That means your ff and your s_client send different lists of ciphersuites.
You seem to invoke s_client with the standard list of ciphersuites...whatever that is. Try invoking s_client with -cipher ECDHE-ECDSA-AES256-SHA. Is the handshake still successful? Check the ciphersuite-id that s_client sends. Obviously it's different from those that ff sends. Now lookup the ciphersuite-ids in the specification and you see which ciphersuites ff and s_client indeed send. HTH, Patrick Eisenacher -----Original Message----- From: Alex Birkett Hi Patrick, Thanks for your response. FF 3.6.2 is sending TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA in it's client hello message. The command line OpenSSL client can be made to connect using this cipher suite. Any ideas? Thanks, Alex On 8 July 2010 13:41, Eisenacher, Patrick <patrick.eisenac...@bdr.de<mailto:patrick.eisenac...@bdr.de>> wrote: Hi Alex, just check the list of ciphersuites that FF sends in its client hello message and you'll see which ciphersuites FF supports. HTH, Patrick Eisenacher -----Original Message----- From: Alex Birkett Hi, Firefox 3.6.2 supports the TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA cipher suite. I've configured Open SSL (version 1.0.0.a) as a test server with what I think is a suitable ECC key/certificate (attached) The keys were created with the attached script. The server was started like this: openssl s_server -cert /home/alex/keys/ssltest/Certs/secp160r2TestServer.pem -cipher ECDHE-ECDSA-AES256-SHA An open ssl client can be successfully connected like this: openssl s_client -connect localhost:4433 The client says the connection is established with the ECDHE-ECDSA-AES256-SHA cipher When a connection with Firefox is attempted the server give a series of errors like this: 140068746417832:error:1408A0C1:SSL routines:SSL3_GET_CLIENT_HELLO:no shared cipher:s3_srvr.c:1216: shutting down SSL Can anybody explain this? Could it be a bug in OpenSSL? -- Alex Birkett mBricks AS Fornebuveien 31, P.O. Box 69 NO-1324 Lysaker, NORWAY www.mbricks.no<http://www.mbricks.no> Follow us on Twitter: www.twitter.com/mBricksTeam<http://www.twitter.com/mBricksTeam>