Clean up derivation of finished/peer finished.

Make this process more readable by having specific client/server functions,
calling the correct one based on s->server. This allows to remove various
SSL_ST_ACCEPT/SSL_ST_CONNECT checks, along with duplicate code.

ok inoguchi@ tb@

1 files changed, 12 insertions, 26 deletions

diff --git a/src/lib/libssl/ssl_pkt.c b/src/lib/libssl/ssl_pkt.c
index a760f90a3a..6e0cfe2102 100644
--- a/src/lib/libssl/ssl_pkt.c
+++ b/src/lib/libssl/ssl_pkt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_pkt.c,v 1.40 2021/03/29 16:46:09 jsing Exp $ */
+/* $OpenBSD: ssl_pkt.c,v 1.41 2021/04/25 13:15:22 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1155,13 +1155,6 @@ int
 ssl3_do_change_cipher_spec(SSL *s)
 {
         int i;
-        const char *sender;
-        int slen;
-
-        if (S3I(s)->hs.state & SSL_ST_ACCEPT)
-                i = SSL3_CHANGE_CIPHER_SERVER_READ;
-        else
-                i = SSL3_CHANGE_CIPHER_CLIENT_READ;
 
         if (S3I(s)->hs.tls12.key_block == NULL) {
                 if (s->session == NULL || s->session->master_key_length == 0) {
@@ -1175,27 +1168,20 @@ ssl3_do_change_cipher_spec(SSL *s)
                         return (0);
         }
 
+        if (S3I(s)->hs.state & SSL_ST_ACCEPT)
+                i = SSL3_CHANGE_CIPHER_SERVER_READ;
+        else
+                i = SSL3_CHANGE_CIPHER_CLIENT_READ;
+
         if (!tls1_change_cipher_state(s, i))
                 return (0);
 
-        /* we have to record the message digest at
-         * this point so we can get it before we read
-         * the finished message */
-        if (S3I(s)->hs.state & SSL_ST_CONNECT) {
-                sender = TLS_MD_SERVER_FINISH_CONST;
-                slen = TLS_MD_SERVER_FINISH_CONST_SIZE;
-        } else {
-                sender = TLS_MD_CLIENT_FINISH_CONST;
-                slen = TLS_MD_CLIENT_FINISH_CONST_SIZE;
-        }
-
-        i = tls1_final_finish_mac(s, sender, slen,
-            S3I(s)->hs.peer_finished);
-        if (i == 0) {
-                SSLerror(s, ERR_R_INTERNAL_ERROR);
-                return 0;
-        }
-        S3I(s)->hs.peer_finished_len = i;
+        /*
+         * We have to record the message digest at this point so we can get it
+         * before we read the finished message.
+         */
+        if (!tls12_derive_peer_finished(s))
+                return (0);
 
         return (1);
 }