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, 10 insertions, 7 deletions

diff --git a/src/lib/libssl/s3_clnt.c b/src/lib/libssl/s3_clnt.c
index 7a327a76a3..f39ae7fab3 100644
--- a/src/lib/libssl/s3_clnt.c
+++ b/src/lib/libssl/s3_clnt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s3_clnt.c,v 1.148 2016/12/04 14:25:44 jsing Exp $ */
+/* $OpenBSD: s3_clnt.c,v 1.149 2016/12/04 14:32:30 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -588,8 +588,11 @@ int
 ssl3_client_hello(SSL *s)
 {
         unsigned char   *bufend, *p, *d;
+        size_t           outlen;
         int              i;
 
+        bufend = (unsigned char *)s->init_buf->data + SSL3_RT_MAX_PLAIN_LENGTH;
+
         if (s->state == SSL3_ST_CW_CLNT_HELLO_A) {
                 SSL_SESSION *sess = s->session;
 
@@ -678,22 +681,22 @@ ssl3_client_hello(SSL *s)
                 }
 
                 /* Ciphers supported */
-                i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &p[2]);
-                if (i == 0) {
+                if (!ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &p[2],
+                    bufend - &p[2], &outlen))
+                        goto err;
+                if (outlen == 0) {
                         SSLerr(SSL_F_SSL3_CLIENT_HELLO,
                             SSL_R_NO_CIPHERS_AVAILABLE);
                         goto err;
                 }
-                s2n(i, p);
-                p += i;
+                s2n(outlen, p);
+                p += outlen;
 
                 /* add in (no) COMPRESSION */
                 *(p++) = 1;
                 *(p++) = 0; /* Add the NULL method */
 
                 /* TLS extensions*/
-                bufend = (unsigned char *)s->init_buf->data +
-                    SSL3_RT_MAX_PLAIN_LENGTH;
                 if ((p = ssl_add_clienthello_tlsext(s, p, bufend)) == NULL) {
                         SSLerr(SSL_F_SSL3_CLIENT_HELLO,
                             ERR_R_INTERNAL_ERROR);