Fix bug in CVE-2011-4619: check we have really received a client hello

before rejecting multiple SGC restarts.

CHANGES

@@ -548,6 +548,13 @@
        Add command line options to s_client/s_server.
      [Steve Henson]
 
+ Changes between 1.0.0g and 1.0.0h [xx XXX xxxx]
+
+  *) Fix CVE-2011-4619: make sure we really are receiving a 
+     client hello before rejecting multiple SGC restarts. Thanks to
+     Ivan Nestlerode <inestlerode@us.ibm.com> for discovering this bug.
+     [Steve Henson]
+
  Changes between 1.0.0f and 1.0.0g [18 Jan 2012]
 
   *) Fix for DTLS DoS issue introduced by fix for CVE-2011-4109.

ssl/s3_srvr.c

@@ -873,14 +873,6 @@ int ssl3_check_client_hello(SSL *s)
 	int ok;
 	long n;
 
-	/* We only allow the client to restart the handshake once per
-	 * negotiation. */
-	if (s->s3->flags & SSL3_FLAGS_SGC_RESTART_DONE)
-		{
-		SSLerr(SSL_F_SSL3_CHECK_CLIENT_HELLO, SSL_R_MULTIPLE_SGC_RESTARTS);
-		return -1;
-		}
-
 	/* this function is called when we really expect a Certificate message,
 	 * so permit appropriate message length */
 	n=s->method->ssl_get_message(s,
@@ -893,6 +885,13 @@ int ssl3_check_client_hello(SSL *s)
 	s->s3->tmp.reuse_message = 1;
 	if (s->s3->tmp.message_type == SSL3_MT_CLIENT_HELLO)
 		{
+		/* We only allow the client to restart the handshake once per
+		 * negotiation. */
+		if (s->s3->flags & SSL3_FLAGS_SGC_RESTART_DONE)
+			{
+			SSLerr(SSL_F_SSL3_CHECK_CLIENT_HELLO, SSL_R_MULTIPLE_SGC_RESTARTS);
+			return -1;
+			}
 		/* Throw away what we have done so far in the current handshake,
 		 * which will now be aborted. (A full SSL_clear would be too much.) */
 #ifndef OPENSSL_NO_DH