For server use a PSK identity hint value in the CERT structure which
is inherited when SSL_new is called and which allows applications to
set hints on a per-SSL basis. The previous version of
SSL_use_psk_identity_hint tried (wrongly) to use the SSL_SESSION structure.

PR#4039
Reviewed-by: NMatt Caswell <matt@openssl.org>

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

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

Reviewed-by: NTim Hudson <tjh@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>

Continuing on from the previous commit this moves the processing of DTLS
CCS messages out of the record layer and into the state machine.
Reviewed-by: NTim Hudson <tjh@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>

Uses the new PACKET code to process the incoming ClientHello including all
extensions etc.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Provide more robust (inline) functions to replace n2s, n2l, etc. These
functions do the same thing as the previous macros, but also keep track
of the amount of data remaining and return an error if we try to read more
data than we've got.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Add support for RSAPSK, DHEPSK and ECDHEPSK server side.

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

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

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

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: NRich Salz <rsalz@openssl.org>

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>

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>

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>

struct ccs_header_st is not used so it should be removed.
Reviewed-by: NRich Salz <rsalz@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>

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>

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

Following the version negotiation rewrite all of the previous code that was
dedicated to version negotiation can now be deleted - all six source files
of it!!
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

This commit changes the way that we do server side protocol version
negotiation. Previously we had a whole set of code that had an "up front"
state machine dedicated to the negotiating the protocol version. This adds
significant complexity to the state machine. Historically the justification
for doing this was the support of SSLv2 which works quite differently to
SSLv3+. However, we have now removed support for SSLv2 so there is little
reason to maintain this complexity.

The one slight difficulty is that, although we no longer support SSLv2, we
do still support an SSLv3+ ClientHello in an SSLv2 backward compatible
ClientHello format. This is generally only used by legacy clients. This
commit adds support within the SSLv3 code for these legacy format
ClientHellos.

Server side version negotiation now works in much the same was as DTLS,
i.e. we introduce the concept of TLS_ANY_VERSION. If s->version is set to
that then when a ClientHello is received it will work out the most
appropriate version to respond with. Also, SSLv23_method and
SSLv23_server_method have been replaced with TLS_method and
TLS_server_method respectively. The old SSLv23* names still exist as
macros pointing at the new name, although they are deprecated.

Subsequent commits will look at client side version negotiation, as well of
removal of the old s23* code.
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>

Since COMP_METHOD is now defined in comp_lcl.h, it is no
longer possible to create new TLS compression methods without
using the OpenSSL source.  Only ZLIB is supported by default.
Also, since the types are opaque, #ifdef guards to use "char *"
instead of the real type aren't necessary.

The changes are actually minor.  Adding missing copyright to some
files makes the diff misleadingly big.
Reviewed-by: NMatt Caswell <matt@openssl.org>

The return value is checked for 0. This is currently safe but we should
really check for <= 0 since -1 is frequently used for error conditions.
Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3
Solutions) for reporting this issue.
Reviewed-by: NAndy Polyakov <appro@openssl.org>

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

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

Also push some usage of last_write_sequence out of dtls1_retransmit_message
and into the record layer.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

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

alert_fragment_len from s->d1 to s->rlayer.d
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

Create dtls_bitmap.h and dtls_bitmap.c
Reviewed-by: NRichard Levitte <levitte@openssl.org>