[openssl.org #2984] OpenSSL 1.0.0k, 1.0.1.d, 1.0.1e fail handshake with DTLS1_BAD_VER

[David Woodhouse via RT]

Since commit a693ead6 in HEAD, 820988a0 in 1.0.2, 014265eb in 1.0.1 and
f852b6079 in 1.0.0, DTLS_BAD_VER (needed for Cisco AnyConnect
compatibility) has been broken.

The check 's->version >= TLS1_1_VERSION || s->version == DTLS1_VERSION'
is redundant anyway since DTLS1_VERSION (0xfeff) is greater than
TLS1_1_VERSION (0x302). We *do*, however, need to include DTLS1_BAD_VER
(0x100) in the set of versions which have an explicit IV.

A patch for 1.0.[12] and HEAD, and a separate patch for 1.0.0, are
attached.

-- 
dwmw2



diff --git a/ssl/s3_cbc.c b/ssl/s3_cbc.c
index 5b3f371..61413b8 100644
--- a/ssl/s3_cbc.c
+++ b/ssl/s3_cbc.c
@@ -148,7 +148,7 @@ int tls1_cbc_remove_padding(const SSL* s,
 	unsigned padding_length, good, to_check, i;
 	const unsigned overhead = 1 /* padding length byte */ + mac_size;
 	/* Check if version requires explicit IV */
-	if (s->version == DTLS1_VERSION)
+	if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
 		{
 		/* These lengths are all public so we can test them in
 		 * non-constant time.

diff --git a/ssl/s3_cbc.c b/ssl/s3_cbc.c
index 2e93657..1db1d8c 100644
--- a/ssl/s3_cbc.c
+++ b/ssl/s3_cbc.c
@@ -146,7 +146,7 @@ int tls1_cbc_remove_padding(const SSL* s,
 	unsigned padding_length, good, to_check, i;
 	const unsigned overhead = 1 /* padding length byte */ + mac_size;
 	/* Check if version requires explicit IV */
-	if (s->version >= TLS1_1_VERSION || s->version == DTLS1_VERSION)
+	if (s->version >= TLS1_1_VERSION || s->version == DTLS1_BAD_VER)
 		{
 		/* These lengths are all public so we can test them in
 		 * non-constant time.

smime.p7s
Description: S/MIME cryptographic signature