Commit 7e840163 authored by Dr. Stephen Henson's avatar Dr. Stephen Henson
Browse files

Add heartbeat extension bounds check. 

A missing bounds check in the handling of the TLS heartbeat extension
can be used to reveal up to 64k of memory to a connected client or
server.

Thanks for Neel Mehta of Google Security for discovering this bug and to
Adam Langley <agl@chromium.org> and Bodo Moeller <bmoeller@acm.org> for
preparing the fix (CVE-2014-0160)
(cherry picked from commit 96db9023)
parent a4896327

CHANGES

+9 −0
Original line number Diff line number Diff line
@@ -4,6 +4,15 @@ 


 Changes between 1.0.1f and 1.0.2 [xx XXX xxxx]



  *) A missing bounds check in the handling of the TLS heartbeat extension

     can be used to reveal up to 64k of memory to a connected client or

     server.



     Thanks for Neel Mehta of Google Security for discovering this bug and to

     Adam Langley <agl@chromium.org> and Bodo Moeller <bmoeller@acm.org> for

     preparing the fix (CVE-2014-0160)

     [Adam Langley, Bodo Moeller]



  *) Fix for the attack described in the paper "Recovering OpenSSL

     ECDSA Nonces Using the FLUSH+RELOAD Cache Side-channel Attack"

     by Yuval Yarom and Naomi Benger. Details can be obtained from:

ssl/d1_both.c

+18 −8
Original line number Diff line number Diff line
@@ -1330,26 +1330,36 @@ dtls1_process_heartbeat(SSL *s) 
	unsigned int payload;

	unsigned int padding = 16; /* Use minimum padding */



	/* Read type and payload length first */

	hbtype = *p++;

	n2s(p, payload);

	pl = p;



	if (s->msg_callback)

		s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,

			&s->s3->rrec.data[0], s->s3->rrec.length,

			s, s->msg_callback_arg);



	/* Read type and payload length first */

	if (1 + 2 + 16 > s->s3->rrec.length)

		return 0; /* silently discard */

	hbtype = *p++;

	n2s(p, payload);

	if (1 + 2 + payload + 16 > s->s3->rrec.length)

		return 0; /* silently discard per RFC 6520 sec. 4 */

	pl = p;



	if (hbtype == TLS1_HB_REQUEST)

		{

		unsigned char *buffer, *bp;

		unsigned int write_length = 1 /* heartbeat type */ +

					    2 /* heartbeat length */ +

					    payload + padding;

		int r;



		if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)

			return 0;



		/* Allocate memory for the response, size is 1 byte

		 * message type, plus 2 bytes payload length, plus

		 * payload, plus padding

		 */

		buffer = OPENSSL_malloc(1 + 2 + payload + padding);

		buffer = OPENSSL_malloc(write_length);

		bp = buffer;



		/* Enter response type, length and copy payload */
@@ -1360,11 +1370,11 @@ dtls1_process_heartbeat(SSL *s) 
		/* Random padding */

		RAND_pseudo_bytes(bp, padding);



		r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);

		r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);



		if (r >= 0 && s->msg_callback)

			s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,

				buffer, 3 + payload + padding,

				buffer, write_length,

				s, s->msg_callback_arg);



		OPENSSL_free(buffer);

ssl/t1_lib.c

+9 −5
Original line number Diff line number Diff line
@@ -3801,16 +3801,20 @@ tls1_process_heartbeat(SSL *s) 
	unsigned int payload;

	unsigned int padding = 16; /* Use minimum padding */



	/* Read type and payload length first */

	hbtype = *p++;

	n2s(p, payload);

	pl = p;



	if (s->msg_callback)

		s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,

			&s->s3->rrec.data[0], s->s3->rrec.length,

			s, s->msg_callback_arg);



	/* Read type and payload length first */

	if (1 + 2 + 16 > s->s3->rrec.length)

		return 0; /* silently discard */

	hbtype = *p++;

	n2s(p, payload);

	if (1 + 2 + payload + 16 > s->s3->rrec.length)

		return 0; /* silently discard per RFC 6520 sec. 4 */

	pl = p;



	if (hbtype == TLS1_HB_REQUEST)

		{

		unsigned char *buffer, *bp;