Convert ssl_cipher_list_to_bytes() to CBB, changing the function to return

the number of bytes written via an explicit *outlen argument and retaining
the return value to indicate success or failure.

ok doug@

1 files changed, 32 insertions, 16 deletions

diff --git a/src/lib/libssl/ssl_lib.c b/src/lib/libssl/ssl_lib.c
index ebe78808c5..5d93a3bc13 100644
--- a/src/lib/libssl/ssl_lib.c
+++ b/src/lib/libssl/ssl_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_lib.c,v 1.121 2016/11/02 11:21:05 jsing Exp $ */
+/* $OpenBSD: ssl_lib.c,v 1.122 2016/12/04 14:32:30 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1363,35 +1363,51 @@ SSL_get_shared_ciphers(const SSL *s, char *buf, int len)
 }
 
 int
-ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, unsigned char *p)
+ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, unsigned char *p,
+    size_t maxlen, size_t *outlen)
 {
-        int              i;
-        SSL_CIPHER      *c;
-        unsigned char   *q;
+        SSL_CIPHER *cipher;
+        int ciphers = 0;
+        CBB cbb;
+        int i;
+
+        *outlen = 0;
 
         if (sk == NULL)
                 return (0);
-        q = p;
+
+        if (!CBB_init_fixed(&cbb, p, maxlen))
+                goto err;
 
         for (i = 0; i < sk_SSL_CIPHER_num(sk); i++) {
-                c = sk_SSL_CIPHER_value(sk, i);
+                cipher = sk_SSL_CIPHER_value(sk, i);
 
                 /* Skip TLS v1.2 only ciphersuites if lower than v1.2 */
-                if ((c->algorithm_ssl & SSL_TLSV1_2) &&
+                if ((cipher->algorithm_ssl & SSL_TLSV1_2) &&
                     (TLS1_get_client_version(s) < TLS1_2_VERSION))
                         continue;
 
-                s2n(ssl3_cipher_get_value(c), p);
+                if (!CBB_add_u16(&cbb, ssl3_cipher_get_value(cipher)))
+                        goto err;
+
+                ciphers++;
         }
 
-        /*
-         * If p == q, no ciphers and caller indicates an error. Otherwise
-         * add SCSV if not renegotiating.
-         */
-        if (p != q && !s->renegotiate)
-                s2n(SSL3_CK_SCSV & SSL3_CK_VALUE_MASK, p);
+        /* Add SCSV if there are other ciphers and we're not renegotiating. */
+        if (ciphers > 0 && !s->renegotiate) {
+                if (!CBB_add_u16(&cbb, SSL3_CK_SCSV & SSL3_CK_VALUE_MASK))
+                        goto err;
+        }
+
+        if (!CBB_finish(&cbb, NULL, outlen))
+                goto err;
+
+        return 1;
+
+ err:
+        CBB_cleanup(&cbb);
 
-        return (p - q);
+        return 0;
 }
 
 STACK_OF(SSL_CIPHER) *