The bookmark API results in a lot of boilerplate error checking that can
be much more easily achieved with a simple struct copy. It also lays the
path for removing the third PACKET field.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Process the ServerKeyExchange message using the PACKET API
Reviewed-by: NTim Hudson <tjh@openssl.org>

Process ServerHello messages using the PACKET API
Reviewed-by: NTim Hudson <tjh@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

Process CertificateRequest messages using the PACKET API
Reviewed-by: NEmilia Käsper <emilia@openssl.org>

Process NewSessionTicket messages using the new PACKET API
Reviewed-by: NEmilia Käsper <emilia@openssl.org>

Process the Certificate Status message using the PACKET API
Reviewed-by: NEmilia Käsper <emilia@openssl.org>

Use the PACKET API to process an incoming server Certificate message.
Reviewed-by: NEmilia Käsper <emilia@openssl.org>

This was obsolete in 2001.  This is not the same as Gost94 digest.
Thanks to Dmitry Belyavsky <beldmit@gmail.com> for review and advice.
Reviewed-by: NMatt Caswell <matt@openssl.org>

If a client receives a ServerKeyExchange for an anon DH ciphersuite with the
value of p set to 0 then a seg fault can occur. This commits adds a test to
reject p, g and pub key parameters that have a 0 value (in accordance with
RFC 5246)

The security vulnerability only affects master and 1.0.2, but the fix is
additionally applied to 1.0.1 for additional confidence.

CVE-2015-1794
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

The handling of incoming CCS records is a little strange. Since CCS is not
a handshake message it is handled differently to normal handshake messages.
Unfortunately whilst technically it is not a handhshake message the reality
is that it must be processed in accordance with the state of the handshake.
Currently CCS records are processed entirely within the record layer. In
order to ensure that it is handled in accordance with the handshake state
a flag is used to indicate that it is an acceptable time to receive a CCS.

Previously this flag did not exist (see CVE-2014-0224), but the flag should
only really be considered a workaround for the problem that CCS is not
visible to the state machine.

Outgoing CCS messages are already handled within the state machine.

This patch makes CCS visible to the TLS state machine. A separate commit
will handle DTLS.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Add support for RSAPSK, DHEPSK and ECDHEPSK client side.

Update various checks to ensure certificate and server key exchange messages
are only expected when required.

Update message handling. PSK server key exchange parsing now expects an
identity hint prefix for all PSK server key exchange messages. PSK
client key exchange message requests PSK identity and key for all PSK
key exchange ciphersuites and includes identity in message.

Update flags for RSA, DH and ECDH so they are also used in PSK.
Reviewed-by: NMatt Caswell <matt@openssl.org>

This flag was not set anywhere within the codebase (only read). It could
only be set by an app reaching directly into s->s3->flags and setting it
directly. However that method became impossible when libssl was opaquified.

Even in 1.0.2/1.0.1 if an app set the flag directly it is only relevant to
ssl3_connect(), which calls SSL_clear() during initialisation that clears
any flag settings. Therefore it could take effect if the app set the flag
after the handshake has started but before it completed. It seems quite
unlikely that any apps really do this (especially as it is completely
undocumented).

The purpose of the flag is suppress flushing of the write bio on the client
side at the end of the handshake after the client has written the Finished
message whilst resuming a session. This enables the client to send
application data as part of the same flight as the Finished message.

This flag also controls the setting of a second flag SSL3_FLAGS_POP_BUFFER.
There is an interesting comment in the code about this second flag in the
implementation of ssl3_write:

	/* This is an experimental flag that sends the
	 * last handshake message in the same packet as the first
	 * use data - used to see if it helps the TCP protocol during
	 * session-id reuse */

It seems the experiment did not work because as far as I can tell nothing
is using this code. The above comment has been in the code since SSLeay.

This commit removes support for SSL3_FLAGS_DELAY_CLIENT_FINISHED, as well
as the associated SSL3_FLAGS_POP_BUFFER.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

The PSK identity hint should be stored in the SSL_SESSION structure
and not in the parent context (which will overwrite values used
by other SSL structures with the same SSL_CTX).
Reviewed-by: NMatt Caswell <matt@openssl.org>

Rewrite ssl3_digest_cached_records handling. Only digest cached records
if digest array is NULL: this means it is safe to call
ssl3_digest_cached_records multiple times (subsequent calls are no op).

Remove flag TLS1_FLAGS_KEEP_HANDSHAKE instead only update handshake buffer
if digest array is NULL.

Add additional "keep" parameter to ssl3_digest_cached_records to indicate
if the handshake buffer should be retained after digesting cached records
(needed for TLS 1.2 client authentication).
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

If RSA or DSA is disabled we will never use a ciphersuite with
RSA/DSA authentication as it is already filtered out by the cipher
list logic.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

As numerous comments indicate the certificate and key array is not an
appopriate structure to store the peers certificate: so remove it and
just the s->session->peer instead.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>
MR #588

Reviewed-by: NMatt Caswell <matt@openssl.org>
MR #588

Remove a comment that suggested further clean up was required.
DH_free() performs the necessary cleanup.

With thanks to the Open Crypto Audit Project for reporting this issue.
Reviewed-by: NRich Salz <rsalz@openssl.org>

The session object on the client side is initially created during
construction of the ClientHello. If the client is DTLS1.2 capable then it
will store 1.2 as the version for the session. However if the server is only
DTLS1.0 capable then when the ServerHello comes back the client switches to
using DTLS1.0 from then on. However the session version does not get
updated. Therefore when the client attempts to resume that session the
server throws an alert because of an incorrect protocol version.
Reviewed-by: NTim Hudson <tjh@openssl.org>

If a NewSessionTicket is received by a multi-threaded client when
attempting to reuse a previous ticket then a race condition can occur
potentially leading to a double free of the ticket data.

CVE-2015-1791

This also fixes RT#3808 where a session ID is changed for a session already
in the client session cache. Since the session ID is the key to the cache
this breaks the cache access.

Parts of this patch were inspired by this Akamai change:
https://github.com/akamai/openssl/commit/c0bf69a791239ceec64509f9f19fcafb2461b0d3Reviewed-by: NRich Salz <rsalz@openssl.org>

Version negotiation was broken (one of the late changes in the review
process broke it). The problem is that TLS clients do not set first_packet,
whereas TLS/DTLS servers and DTLS clients do. The simple fix is to set
first_packet for TLS clients too.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Given the pervasive nature of TLS extensions it is inadvisable to run
OpenSSL without support for them. It also means that maintaining
the OPENSSL_NO_TLSEXT option within the code is very invasive (and probably
not well tested). Therefore it is being removed.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

40 bit ciphers are limited to 512 bit RSA, 56 bit ciphers to 1024 bit.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

Move per-connection state out of the CERT structure: which should just be
for shared configuration data (e.g. certificates to use).

In particular move temporary premaster secret, raw ciphers, peer signature
algorithms and shared signature algorithms.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Move these functions into t1_clnt.c, t1_srvr.c and t1_meth.c and take
advantage of the existing tls1_get*_method() functions that all the other
methods are using. Since these now have to support SSLv3 anyway we might
as well use the same set of get functions for both TLS and SSLv3.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Miscellaneous updates following review comments on the version negotiation
rewrite patches.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Continuing from the previous commit this changes the way we do client side
version negotiation. Similarly all of the s23* "up front" state machine code
has been avoided and again things now work much the same way as they already
did for DTLS, i.e. we just do most of the work in the
ssl3_get_server_hello() function.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Remove RFC2712 Kerberos support from libssl. This code and the associated
standard is no longer considered fit-for-purpose.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

If server requests a certificate, but the client doesn't send one, cache
digested records. This is an optimisation and ensures the correct finished
mac is used when extended master secret is used with client authentication.
Reviewed-by: NTim Hudson <tjh@openssl.org>