Remove cipher_list_by_id.

When parsing a cipher string, a cipher list is created, before being
duplicated and sorted - the second copy being stored as cipher_list_by_id.
This is done only so that a client can ensure that the cipher selected by
a server is in the cipher list. This is pretty pointless given that most
clients are short-lived and that we already had to iterate over the cipher
list in order to build the client hello. Additionally, any update to the
cipher list requires that cipher_list_by_id also be updated and kept in
sync.

Remove all of this and replace it with a simple linear scan - the overhead
of duplicating and sorting the cipher list likely exceeds that of a simple
linear scan over the cipher list (64 maximum, more typically ~9 or so).

ok beck@ tb@

1 files changed, 1 insertions, 5 deletions

diff --git a/src/lib/libssl/ssl_srvr.c b/src/lib/libssl/ssl_srvr.c
index 745b15aad0..cbf7c180b5 100644
--- a/src/lib/libssl/ssl_srvr.c
+++ b/src/lib/libssl/ssl_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_srvr.c,v 1.81 2020/08/31 14:04:51 tb Exp $ */
+/* $OpenBSD: ssl_srvr.c,v 1.82 2020/09/11 17:36:27 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1096,11 +1096,7 @@ ssl3_get_client_hello(SSL *s)
                         s->session->cipher = pref_cipher;
 
                         sk_SSL_CIPHER_free(s->cipher_list);
-                        sk_SSL_CIPHER_free(s->internal->cipher_list_by_id);
-
                         s->cipher_list = sk_SSL_CIPHER_dup(s->session->ciphers);
-                        s->internal->cipher_list_by_id =
-                            sk_SSL_CIPHER_dup(s->session->ciphers);
                 }
         }