Remove cipher from SSL_SESSION.

For a long time SSL_SESSION has had both a cipher ID and a pointer to
an SSL_CIPHER (and not both are guaranteed to be populated). There is also
a pointer to an SSL_CIPHER in the SSL_HANDSHAKE that denotes the cipher
being used for this connection. Some code has been using the cipher from
SSL_SESSION and some code has been using the cipher from SSL_HANDSHAKE.

Remove cipher from SSL_SESSION and use the version in SSL_HANDSHAKE
everywhere. If resuming from a session then we need to use the SSL_SESSION
cipher ID to set the SSL_HANDSHAKE cipher. And we still need to ensure that
we update the cipher ID in the SSL_SESSION whenever the SSL_HANDSHAKE
cipher changes (this only occurs in a few places).

ok tb@

1 files changed, 5 insertions, 4 deletions

diff --git a/src/lib/libssl/ssl_pkt.c b/src/lib/libssl/ssl_pkt.c
index 2c33c45386..7d6785a3de 100644
--- a/src/lib/libssl/ssl_pkt.c
+++ b/src/lib/libssl/ssl_pkt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_pkt.c,v 1.66 2023/07/11 17:02:47 tb Exp $ */
+/* $OpenBSD: ssl_pkt.c,v 1.67 2024/07/20 04:04:23 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -904,7 +904,7 @@ ssl3_read_handshake_unexpected(SSL *s)
                  * It should be impossible to hit this, but keep the safety
                  * harness for now...
                  */
-                if (s->session == NULL || s->session->cipher == NULL)
+                if (s->session == NULL || s->s3->hs.cipher == NULL)
                         return 1;
 
                 /*
@@ -953,7 +953,7 @@ ssl3_read_handshake_unexpected(SSL *s)
                         return -1;
                 }
 
-                if (s->session == NULL || s->session->cipher == NULL) {
+                if (s->session == NULL || s->s3->hs.cipher == NULL) {
                         SSLerror(s, ERR_R_INTERNAL_ERROR);
                         return -1;
                 }
@@ -1235,7 +1235,8 @@ ssl3_do_change_cipher_spec(SSL *s)
                         return (0);
                 }
 
-                s->session->cipher = s->s3->hs.cipher;
+                s->session->cipher_id = s->s3->hs.cipher->id;
+
                 if (!tls1_setup_key_block(s))
                         return (0);
         }