From: Dr. Stephen Henson <steve@openssl.org>
Date: Wed, 17 Feb 2010 18:38:31 +0000 (+0000)
Subject: Allow renegotiation if SSL_OP_LEGACY_SERVER_CONNECT is set as well as
X-Git-Tag: OpenSSL-fips-2_0-rc1~1265
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=c2c49969e236058090c081e591272ea325ca49b6;p=oweals%2Fopenssl.git

Allow renegotiation if SSL_OP_LEGACY_SERVER_CONNECT is set as well as
initial connection to unpatched servers. There are no additional security
concerns in doing this as clients don't see renegotiation during an
attack anyway.
---

diff --git a/CHANGES b/CHANGES
index 4c553898a6..6213877724 100644
--- a/CHANGES
+++ b/CHANGES
@@ -926,7 +926,7 @@
      [Steve Henson]
 
   *) Add option SSL_OP_LEGACY_SERVER_CONNECT which will allow clients to
-     connect (but not renegotiate) with servers which do not support RI.
+     connect and renegotiate with servers which do not support RI.
      Until RI is more widely deployed this option is enabled by default.
      [Steve Henson]
 
diff --git a/doc/ssl/SSL_CTX_set_options.pod b/doc/ssl/SSL_CTX_set_options.pod
index 3e61a36e17..1abda2898e 100644
--- a/doc/ssl/SSL_CTX_set_options.pod
+++ b/doc/ssl/SSL_CTX_set_options.pod
@@ -237,7 +237,7 @@ OpenSSL 0.9.8m and later always attempts to use secure renegotiation as
 described in RFC5746. This counters the prefix attack described in
 CVE-2009-3555 and elsewhere.
 
-The deprecated and highly broken SSLv2 protocol does not support secure
+The deprecated and highly broken SSLv2 protocol does not support
 renegotiation at all: its use is B<strongly> discouraged.
 
 This attack has far reaching consequences which application writers should be
@@ -276,10 +276,14 @@ was refused.
 =head2 Patched OpenSSL client and unpatched server.
 
 If the option B<SSL_OP_LEGACY_SERVER_CONNECT> is set then initial connections
-between patched OpenSSL clients and unpatched servers succeed. This option
-is currently set by default even though it has security implications: otherwise
-it would be impossible to connect to unpatched servers (i.e. all of them
-initially) and this is clearly not acceptable.
+and renegotiation between patched OpenSSL clients and unpatched servers
+succeeds.
+
+This option is currently set by default even though it has security
+implications: otherwise it would be impossible to connect to unpatched servers
+(i.e. all of them initially) and this is clearly not acceptable. Renegotiation
+is permitted because this does not add any additional security issues: during
+an attack clients do not see any renegotiations anyway.
 
 As more servers become patched the option B<SSL_OP_LEGACY_SERVER_CONNECT> will
 B<not> be set by default in a future version of OpenSSL.
@@ -292,10 +296,9 @@ unpatched servers (and thus avoid any security issues) should always B<clear>
 B<SSL_OP_LEGACY_SERVER_CONNECT> using SSL_CTX_clear_options() or
 SSL_clear_options().
 
-Renegotiation between a patched OpenSSL client and unpatched server follows
-the same scheme as between an unpatched client and a patched OpenSSL server:
-i.e. it is not permitted unless the option
-B<SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION> is set.
+As in the previous case if the option
+B<SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION> is set then renegotiation
+B<always> succeeds.
 
 =head1 RETURN VALUES
 
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index b50d2a52f6..9ee7e7d717 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -1157,8 +1157,8 @@ int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
 	 * which doesn't support RI so for the immediate future tolerate RI
 	 * absence on initial connect only.
 	 */
-	if (!renegotiate_seen && 
-		(s->new_session || !(s->options & SSL_OP_LEGACY_SERVER_CONNECT))
+	if (!renegotiate_seen
+		&& !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
 		&& !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 		{
 		*al = SSL_AD_HANDSHAKE_FAILURE;