untrusted comment: signature from openbsd 5.5 base secret key
RWRGy8gxk9N930mZSNhSVZg9DPFLNT0qQcEGhQeQ55awDf4RfJqPXB6lz71jQatqYzr3XkzyUyckpP4nSCE+XmoICZEPwVhjhA8=
OpenBSD 5.5 errata 2, Apr 8, 2014: Missing bounds checking in OpenSSL's
implementation of the TLS/DTLS heartbeat extension (RFC6520) which, if
exploited, can result in a leak of memory contents.
After patching, private keys and certificates exposed to services running
this code (for example web/mail server SSL certificates) should be replaced
and old certificates revoked.
Only SSL/TLS services are affected. Software that uses libcrypto alone
is not affected. In particular, ssh/sshd are not affected and there
is no need to regenerate SSH host keys that have not otherwise been
exposed.
Apply patch using:
signify -Vep /etc/signify/openbsd-55-base.pub -x 002_openssl.patch.sig \
-m - | (cd /usr/src && patch -p0)
Then build and install libssl
cd /usr/src/lib/libssl/ssl
make obj
make
make install
Also recompile any statically-linked binaries depending on it - in
the base OS, this is just ftp(1):
cd /usr/src/usr.bin/ftp
make obj
make clean
make
make install
Then restart services which depend on SSL.
Index: lib/libssl/src/ssl/d1_both.c
===================================================================
RCS file: /cvs/src/lib/libssl/src/ssl/d1_both.c,v
retrieving revision 1.2
diff -u -p -r1.2 d1_both.c
--- lib/libssl/src/ssl/d1_both.c 27 Feb 2014 21:04:57 -0000 1.2
+++ lib/libssl/src/ssl/d1_both.c 8 Apr 2014 00:22:22 -0000
@@ -1459,26 +1459,36 @@ 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;
1