The flag SSL_OP_MSIE_SSLV2_RSA_PADDING hasn't done anything since OpenSSL
0.9.7h but deleting it will break source compatibility with any software
that references it. Restore it but #define to zero.
(cherry picked from commit b17d6b8d1d)
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
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.
When deciding whether to use TLS 1.2 PRF and record hash algorithms
use the version number in the corresponding SSL_METHOD structure
instead of the SSL structure. The SSL structure version is sometimes
inaccurate. Note: OpenSSL 1.0.2 and later effectively do this already.
(CVE-2013-6449)
PR: 2808
With DTLS/SCTP the SCTP extension SCTP-AUTH is used to protect DATA and
FORWARD-TSN chunks. The key for this extension is derived from the
master secret and changed with the next ChangeCipherSpec, whenever a new
key has been negotiated. The following Finished then already uses the
new key. Unfortunately, the ChangeCipherSpec and Finished are part of
the same flight as the ClientKeyExchange, which is necessary for the
computation of the new secret. Hence, these messages are sent
immediately following each other, leaving the server very little time to
compute the new secret and pass it to SCTP before the finished arrives.
So the Finished is likely to be discarded by SCTP and a retransmission
becomes necessary. To prevent this issue, the Finished of the client is
still sent with the old key.
(cherry picked from commit 9fb523adce)
(cherry picked from commit b9ef52b078)
Since the TLS 1.2 supported signature algorithms extension is less
sophisticaed in OpenSSL 1.0.1 this has to be done in two stages.
RSA+MD5 is removed from supported signature algorithms extension:
any compliant implementation should never use RSA+MD5 as a result.
To cover the case of a broken implementation using RSA+MD5 anyway
disable lookup of MD5 algorithm in TLS 1.2.
(I'd rather use an option, but it appears that the options field is
full.)
Now, we send the time in the gmt_unix_time field if the appropriate
one of these mode options is set, but randomize the field if the flag
is not set.
Instead, send random bytes.
While the gmt_unix_time record was added in an ostensible attempt to
mitigate the dangers of a bad RNG, its presence leaks the host's view
of the current time in the clear. This minor leak can help
fingerprint TLS instances across networks and protocols... and what's
worse, it's doubtful thet the gmt_unix_time record does any good at
all for its intended purpose, since:
* It's quite possible to open two TLS connections in one second.
* If the PRNG output is prone to repeat itself, ephemeral
* handshakes (and who knows what else besides) are broken.
This fix ensures that
* A HelloRequest is retransmitted if not responded by a ClientHello
* The HelloRequest "consumes" the sequence number 0. The subsequent
ServerHello uses the sequence number 1.
* The client also expects the sequence number of the ServerHello to
be 1 if a HelloRequest was received earlier.
This patch fixes the RFC violation.
(cherry picked from commit b62f4daac0)
The version check for DTLS1_VERSION was redundant as
DTLS1_VERSION > TLS1_1_VERSION, however we do need to
check for DTLS1_BAD_VER for compatibility.
PR:2984
(cherry picked from commit d980abb22e)
Now we set the current certificate to the one used by a server
there is no need to call ssl_get_server_send_cert which will
fail if we haven't sent a certificate yet.
Fix the calculation that checks there is enough room in a record
after removing padding and optional explicit IV. (by Steve)
For AEAD remove the correct number of padding bytes (by Andy)
MD5 should use little endian order. Fortunately the only ciphersuite
affected is EXP-RC2-CBC-MD5 (TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5) which
is a rarely used export grade ciphersuite.
We have to use EVP in FIPS mode so we can only partially mitigate
timing differences.
Make an extra call to EVP_DigestSignUpdate to hash additonal blocks
to cover any timing differences caused by removal of padding.
