In ssl3_get_client_hello (ssl/s3_srvr.c), generate a fatal alert if

client_version is smaller than the protocol version in use.
Also change ssl23_get_client_hello (ssl/s23_srvr.c) to select TLS 1.0
if the client demanded SSL 3.0 but only TLS 1.0 is enabled; then the
client will at least see that alert.

CHANGES

@@ -4,6 +4,14 @@
 
  Changes between 0.9.6b and 0.9.6c  [XX xxx XXXX]
 
+  *) In ssl3_get_client_hello (ssl/s3_srvr.c), generate a fatal alert
+     (sent using the client's version number) if client_version is
+     smaller than the protocol version in use.  Also change
+     ssl23_get_client_hello (ssl/s23_srvr.c) to select TLS 1.0 if
+     the client demanded SSL 3.0 but only TLS 1.0 is enabled; then
+     the client will at least see that alert.
+     [Bodo Moeller]
+
   *) Fix ssl3_get_message (ssl/s3_both.c) to handle message fragmentation
      correctly.
      [Bodo Moeller]

ssl/s23_pkt.c

@@ -55,6 +55,59 @@
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
 
 #include <stdio.h>
 #include <errno.h>

ssl/s23_srvr.c

@@ -55,6 +55,59 @@
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2001 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
 
 #include <stdio.h>
 #include <openssl/buffer.h>
@@ -376,10 +429,21 @@ int ssl23_get_client_hello(SSL *s)
 					type=3;
 					}
 				}
-			else if (!(s->options & SSL_OP_NO_SSLv3))
+			else
 				{
-				s->version=SSL3_VERSION;
+				/* client requests SSL 3.0 */
-				type=3;
+				if (!(s->options & SSL_OP_NO_SSLv3))
+					{
+					s->version=SSL3_VERSION;
+					type=3;
+					}
+				else if (!(s->options & SSL_OP_NO_TLSv1))
+					{
+					/* we won't be able to use TLS of course,
+					 * but this will send an appropriate alert */
+					s->version=TLS1_VERSION;
+					type=3;
+					}
 				}
 			}
 		else if ((strncmp("GET ", (char *)p,4) == 0) ||

ssl/s3_pkt.c

@@ -1177,6 +1177,8 @@ void ssl3_send_alert(SSL *s, int level, int desc)
 	{
 	/* Map tls/ssl alert value to correct one */
 	desc=s->method->ssl3_enc->alert_value(desc);
+	if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
+		desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
 	if (desc < 0) return;
 	/* If a fatal one, remove from cache */
 	if ((level == 2) && (s->session != NULL))

ssl/s3_srvr.c

@@ -662,6 +662,18 @@ static int ssl3_get_client_hello(SSL *s)
 	s->client_version=(((int)p[0])<<8)|(int)p[1];
 	p+=2;
 
+	if (s->client_version < s->version)
+		{
+		SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO, SSL_R_WRONG_VERSION_NUMBER);
+		if ((s->client_version>>8) == SSL3_VERSION_MAJOR) 
+			{
+			/* similar to ssl3_get_record, send alert using remote version number */
+			s->version = s->client_version;
+			}
+		al = SSL_AD_PROTOCOL_VERSION;
+		goto f_err;
+		}
+
 	/* load the client random */
 	memcpy(s->s3->client_random,p,SSL3_RANDOM_SIZE);
 	p+=SSL3_RANDOM_SIZE;