Limit the number of empty records that will be processed consecutively
in order to prevent ssl3_get_record from never returning.
Reported by "oftc_must_be_destroyed" and George Kadianakis.
Reviewed-by: Bodo Moeller <bodo@openssl.org>
(cherry picked from commit 3aac17a82f)
Only accept change cipher spec when it is expected instead of at any
time. This prevents premature setting of session keys before the master
secret is determined which an attacker could use as a MITM attack.
Thanks to KIKUCHI Masashi (Lepidum Co. Ltd.) for reporting this issue
and providing the initial fix this patch is based on.
When sending an invalid version number alert don't change the
version number to the client version if a session is already
established.
Thanks to Marek Majkowski for additional analysis of this issue.
PR#3191
The previous CBC patch was bugged in that there was a path through enc()
in s3_pkt.c/d1_pkt.c which didn't set orig_len. orig_len would be left
at the previous value which could suggest that the packet was a
sufficient length when it wasn't.
This patch makes the decoding of SSLv3 and TLS CBC records constant
time. Without this, a timing side-channel can be used to build a padding
oracle and mount Vaudenay's attack.
This patch also disables the stitched AESNI+SHA mode pending a similar
fix to that code.
In order to be easy to backport, this change is implemented in ssl/,
rather than as a generic AEAD mode. In the future this should be changed
around so that HMAC isn't in ssl/, but crypto/ as FIPS expects.
This change adds CRYPTO_memcmp, which compares two vectors of bytes in
an amount of time that's independent of their contents. It also changes
several MAC compares in the code to use this over the standard memcmp,
which may leak information about the size of a matching prefix.
Reported by: Phil Pennock <openssl-dev@spodhuis.org>
Make renegotiation work for TLS 1.2, 1.1 by not using a lower record
version client hello workaround if renegotiating.
Some servers hang when presented with a client hello record length exceeding
255 bytes but will work with longer client hellos if the TLS record version
in client hello does not exceed TLS v1.0. Unfortunately this doesn't fix all
cases...
Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>
Reviewed by: steve
Setting SSL_MODE_RELEASE_BUFFERS should be ignored for DTLS, but instead causes
the program to crash. This is due to missing version checks and is fixed with
this patch.
offending record queued as 'pending'. The DTLS code doesn't expect this,
and we end up hitting an OPENSSL_assert() in do_dtls1_write().
The simple fix is just _not_ to leave it queued. In DTLS, dropping
packets is perfectly acceptable -- and even preferable. If we wanted a
service with retries and guaranteed delivery, we'd be using TCP.
PR: #1703
Submitted by: David Woodhouse <dwmw2@infradead.org>
Also, get rid of compile-time switch OPENSSL_NO_RELEASE_BUFFERS
because it was rather pointless (the new behavior has to be explicitly
requested by setting SSL_MODE_RELEASE_BUFFERS anyway).
