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)
diff --git a/CHANGES b/CHANGES
index 2602cfa..111db93 100644
--- a/CHANGES
+++ b/CHANGES
@@ -273,6 +273,11 @@
Changes between 1.0.1e and 1.0.2 [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]
+
*) TLS pad extension: draft-agl-tls-padding-02
Workaround for the "TLS hang bug" (see FAQ and PR#2771): if the
diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index f7947bd..f0c5962 100644
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -214,6 +214,12 @@
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/t1_enc.c b/ssl/t1_enc.c
index acc5f21..0432801 100644
--- a/ssl/t1_enc.c
+++ b/ssl/t1_enc.c
@@ -414,15 +414,20 @@
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)
{
