Fix DTLS retransmission from previous session.

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.
(cherry picked from commit 34628967f1e65dc8f34e000f0f5518e21afbfc7b)

Conflicts:

	ssl/ssl_locl.h

diff --git a/CHANGES b/CHANGES
index 422945083851ff97d1cd7ba6efe5c89d2ae01915..33cb8c6d7640a055b29227ea298d84d9dc3b5c78 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,11 @@
 
  Changes between 1.0.0k and 1.0.0l [xx XXX xxxx]
 
+  *) Keep original DTLS digest and encryption contexts in retransmission
+     structures so we can use the previous session parameters if they need
+     to be resent. (CVE-2013-6450)
+     [Steve Henson]
+
   *) Add option SSL_OP_SAFARI_ECDHE_ECDSA_BUG (part of SSL_OP_ALL) which
      avoids preferring ECDHE-ECDSA ciphers when the client appears to be
      Safari on OS X.  Safari on OS X 10.8..10.8.3 advertises support for

diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index 7cf4b7a73350a1844f207b0ed1d15eb92f4e60cb..c5484c552100554a809aba6edd79b5b9cd4fb3e6 100644 (file)
--- 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 b0dab18069b7f250800790e3efa9bfdabb7aec5b..2a80b8aff6d1635b08f3aacc52d6a9c2913fece0 100644 (file)
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -600,6 +600,8 @@ 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_tls1_meth_func(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 d67f6f19d9654663210db794ac26acdd26218dd5..6c76b5c19c1534ec7bf7503de579582e65c64755 100644 (file)
--- a/ssl/t1_enc.c
+++ b/ssl/t1_enc.c
@@ -403,15 +403,20 @@ 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)
                        {