Got it! Thanks for the detailed explanation. I did not realize that the same ciphers were used by both SSL3 and TLS1. The behavior now makes all the sense in the world. Thanks! -----Original Message----- From: openssl-users [mailto:openssl-users-bounces@xxxxxxxxxxx] On Behalf Of Viktor Dukhovni Sent: Tuesday, April 07, 2015 8:32 AM To: openssl-users at openssl.org Subject: Re: Disable SSL3 and enable TLS1? / Ambiguous "DES-CBC3-SHA" On Tue, Apr 07, 2015 at 08:09:31AM -0700, David Rueter wrote: > >> You're confusing SSLv3 the protocol, with SSLv3 ciphersuites. > > Yes, I admit I am not distinguishing between these. However, !SSLv3 > in the cipher list does evidently disable the SSLv3 protocol as > well--as evidenced by testing with https://www.ssllabs.com/ssltest When there are no SSLv3 ciphers left, the protocol is not offerred, but this also disables TLSv1 and TLSv1.1 as they use the same set of ciphers. > From the symptoms, it sure seems like OpenSSL mistakenly uses the > string "DES-CBC3-SHA" to refer to both TLS and SSL3 (see > https://www.openssl.org/docs/apps/ciphers.html ) There is no mistake. The same cipher-suite: DES-CBC3-SHA SSLv3 Kx=RSA Au=RSA Enc=3DES(168) Mac=SHA1 applies to SSLv3, TLSv1, TLSv1.1 and TLSv1.2. > intentional? In other words, is the SSLv3 cipher > SSL_RSA_WITH_3DES_EDE_CBC_SHA actually the same as the TLS cipher > TLS_RSA_WITH_[3]DES_[EDE_]CBC_SHA? Yes, they are one and the same (SSL 3.0, TLS 1.0, TLS 1.1, TLS 1.2): RFC 6101: CipherSuite SSL_RSA_WITH_3DES_EDE_CBC_SHA = { 0x00,0x0A }; RFC 2246: CipherSuite TLS_RSA_WITH_3DES_EDE_CBC_SHA = { 0x00,0x0A }; RFC 4346: CipherSuite TLS_RSA_WITH_3DES_EDE_CBC_SHA = { 0x00,0x0A }; RFC 5246: CipherSuite TLS_RSA_WITH_3DES_EDE_CBC_SHA = { 0x00,0x0A }; As for: CipherSuite TLS_RSA_WITH_DES_CBC_SHA = { 0x00,0x09 }; it is not triple DES, it is single-DES, and corresponds (RFC 6101) to: CipherSuite SSL_RSA_WITH_DES_CBC_SHA = { 0x00,0x09 }; which OpenSSL calls: DES-CBC-SHA SSLv3 Kx=RSA Au=RSA Enc=DES(56) Mac=SHA1 -- Viktor. _______________________________________________ openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
