Security Advisory - openssl - CVE-2013-6450

The DTLS retransmission implementation in OpenSSL through 0.9.8y and 1.x
through 1.0.1e does not properly maintain data structures for digest and
encryption contexts, which might allow man-in-the-middle attackers to
trigger the use of a different context by interfering with packet delivery,
related to ssl/d1_both.c and ssl/t1_enc.c.

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 81 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/openssl/openssl-1.0.1e/0001-Fix-DTLS-retransmission-from-previous-session.patch b/meta/recipes-connectivity/openssl/openssl-1.0.1e/0001-Fix-DTLS-retransmission-from-previous-session.patch
new file mode 100644
index 0000000000..39592e2d67
--- /dev/null
+++ b/meta/recipes-connectivity/openssl/openssl-1.0.1e/0001-Fix-DTLS-retransmission-from-previous-session.patch
@@ -0,0 +1,81 @@
+From 34628967f1e65dc8f34e000f0f5518e21afbfc7b Mon Sep 17 00:00:00 2001
+From: "Dr. Stephen Henson" <steve@openssl.org>
+Date: Fri, 20 Dec 2013 15:26:50 +0000
+Subject: [PATCH] Fix DTLS retransmission from previous session.
+
+Upstream-Status: Backport
+commit 34628967f1e65dc8f34e000f0f5518e21afbfc7b upstream
+
+For DTLS we might need to retransmit messages from the previous session
+so keep a copy of write context in DTLS retransmission buffers instead
+of replacing it after sending CCS. CVE-2013-6450.
+---
+ ssl/d1_both.c  |    6 ++++++
+ ssl/ssl_locl.h |    2 ++
+ ssl/t1_enc.c   |   17 +++++++++++------
+ 4 files changed, 24 insertions(+), 6 deletions(-)
+
+diff --git a/ssl/d1_both.c b/ssl/d1_both.c
+index 65ec001..7a5596a 100644
+--- a/ssl/d1_both.c
++++ b/ssl/d1_both.c
+@@ -214,6 +214,12 @@ dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
+ static void
+ dtls1_hm_fragment_free(hm_fragment *frag)
+ 	{
++
++	if (frag->msg_header.is_ccs)
++		{
++		EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
++		EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
++		}
+ 	if (frag->fragment) OPENSSL_free(frag->fragment);
+ 	if (frag->reassembly) OPENSSL_free(frag->reassembly);
+ 	OPENSSL_free(frag);
+diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
+index 96ce9a7..e485907 100644
+--- a/ssl/ssl_locl.h
++++ b/ssl/ssl_locl.h
+@@ -621,6 +621,8 @@ extern SSL3_ENC_METHOD TLSv1_enc_data;
+ extern SSL3_ENC_METHOD SSLv3_enc_data;
+ extern SSL3_ENC_METHOD DTLSv1_enc_data;
+ 
++#define SSL_IS_DTLS(s) (s->method->version == DTLS1_VERSION)
++
+ #define IMPLEMENT_tls_meth_func(version, func_name, s_accept, s_connect, \
+ 				s_get_meth) \
+ const SSL_METHOD *func_name(void)  \
+diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c
+index 72015f5..56db834 100644
+--- a/ssl/t1_enc.c
++++ b/ssl/t1_enc.c
+@@ -414,15 +414,20 @@ int tls1_change_cipher_state(SSL *s, int which)
+ 			s->mac_flags |= SSL_MAC_FLAG_WRITE_MAC_STREAM;
+ 			else
+ 			s->mac_flags &= ~SSL_MAC_FLAG_WRITE_MAC_STREAM;
+-		if (s->enc_write_ctx != NULL)
++		if (s->enc_write_ctx != NULL && !SSL_IS_DTLS(s))
+ 			reuse_dd = 1;
+-		else if ((s->enc_write_ctx=OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL)
++		else if ((s->enc_write_ctx=EVP_CIPHER_CTX_new()) == NULL)
+ 			goto err;
+-		else
+-			/* make sure it's intialized in case we exit later with an error */
+-			EVP_CIPHER_CTX_init(s->enc_write_ctx);
+ 		dd= s->enc_write_ctx;
+-		mac_ctx = ssl_replace_hash(&s->write_hash,NULL);
++		if (SSL_IS_DTLS(s))
++			{
++			mac_ctx = EVP_MD_CTX_create();
++			if (!mac_ctx)
++				goto err;
++			s->write_hash = mac_ctx;
++			}
++		else
++			mac_ctx = ssl_replace_hash(&s->write_hash,NULL);
+ #ifndef OPENSSL_NO_COMP
+ 		if (s->compress != NULL)
+ 			{
+-- 
+1.7.5.4
+