Pull out (and largely rewrite) the code that determines the enabled

protocol version range.

This also fixes a bug whereby if all protocols were disabled, the client
would still use TLSv1.2 in the client hello, only to have if fail with
unsupported version when it received and processed the server hello.

ok doug@

1 files changed, 9 insertions, 38 deletions

diff --git a/src/lib/libssl/s23_clnt.c b/src/lib/libssl/s23_clnt.c
index 8674cdf627..2511a94b28 100644
--- a/src/lib/libssl/s23_clnt.c
+++ b/src/lib/libssl/s23_clnt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s23_clnt.c,v 1.47 2016/12/04 14:32:30 jsing Exp $ */
+/* $OpenBSD: s23_clnt.c,v 1.48 2016/12/30 16:57:01 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -231,43 +231,15 @@ ssl23_client_hello(SSL *s)
         unsigned char *buf;
         unsigned char *p, *d;
         unsigned long l;
-        int version = 0, version_major, version_minor;
-        int ret;
-        unsigned long mask, options = s->options;
+        uint16_t version;
         size_t outlen;
-
-        /*
-         * SSL_OP_NO_X disables all protocols above X *if* there are
-         * some protocols below X enabled. This is required in order
-         * to maintain "version capability" vector contiguous. So
-         * that if application wants to disable TLS1.0 in favour of
-         * TLS1>=1, it would be insufficient to pass SSL_NO_TLSv1, the
-         * answer is SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2.
-         */
-        mask = SSL_OP_NO_TLSv1_1|SSL_OP_NO_TLSv1;
-        version = TLS1_2_VERSION;
-
-        if ((options & SSL_OP_NO_TLSv1_2) && (options & mask) != mask)
-                version = TLS1_1_VERSION;
-        mask &= ~SSL_OP_NO_TLSv1_1;
-        if ((options & SSL_OP_NO_TLSv1_1) && (options & mask) != mask)
-                version = TLS1_VERSION;
-        mask &= ~SSL_OP_NO_TLSv1;
+        int ret;
 
         buf = (unsigned char *)s->init_buf->data;
         if (s->state == SSL23_ST_CW_CLNT_HELLO_A) {
                 arc4random_buf(s->s3->client_random, SSL3_RANDOM_SIZE);
 
-                if (version == TLS1_2_VERSION) {
-                        version_major = TLS1_2_VERSION_MAJOR;
-                        version_minor = TLS1_2_VERSION_MINOR;
-                } else if (version == TLS1_1_VERSION) {
-                        version_major = TLS1_1_VERSION_MAJOR;
-                        version_minor = TLS1_1_VERSION_MINOR;
-                } else if (version == TLS1_VERSION) {
-                        version_major = TLS1_VERSION_MAJOR;
-                        version_minor = TLS1_VERSION_MINOR;
-                } else {
+                if (ssl_enabled_version_range(s, NULL, &version) == -1) {
                         SSLerr(SSL_F_SSL23_CLIENT_HELLO,
                             SSL_R_NO_PROTOCOLS_AVAILABLE);
                         return (-1);
@@ -283,8 +255,8 @@ ssl23_client_hello(SSL *s)
                  */
                 d = p = &(buf[SSL3_RT_HEADER_LENGTH + SSL3_HM_HEADER_LENGTH]);
 
-                *(p++) = version_major;
-                *(p++) = version_minor;
+                *(p++) = version >> 8;
+                *(p++) = version & 0xff;
 
                 /* Random stuff */
                 memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
@@ -334,7 +306,7 @@ ssl23_client_hello(SSL *s)
                 /* fill in 5-byte record header */
                 d = buf;
                 *(d++) = SSL3_RT_HANDSHAKE;
-                *(d++) = version_major;
+                *(d++) = version >> 8;
 
                 /*
                  * Some servers hang if we use long client hellos
@@ -343,7 +315,7 @@ ssl23_client_hello(SSL *s)
                 if (TLS1_get_client_version(s) > TLS1_VERSION)
                         *(d++) = 1;
                 else
-                        *(d++) = version_minor;
+                        *(d++) = version & 0xff;
                 s2n((int)l, d);
 
                 /* number of bytes to write */
@@ -362,8 +334,7 @@ ssl23_client_hello(SSL *s)
 
         if ((ret >= 2) && s->msg_callback) {
                 /* Client Hello has been sent; tell msg_callback */
-
-                s->msg_callback(1, version, SSL3_RT_HANDSHAKE,
+                s->msg_callback(1, s->client_version, SSL3_RT_HANDSHAKE,
                     s->init_buf->data + 5, ret - 5, s, s->msg_callback_arg);
         }