Commit e481f9b9 removed OPENSSL_NO_TLSEXT from the code.

Previously if OPENSSL_NO_TLSEXT *was not* defined then the server random was
filled during getting of the ClientHello. If it *was* defined then the
server random would be filled in ssl3_send_server_hello(). Unfortunately in
commit e481f9b9

 the OPENSSL_NO_TLSEXT guards were removed but *both*
server random fillings were left in. This could cause problems for session
ticket callbacks.

Reviewed-by: Stephen Henson <steve@openssl.org>

From a CloudFlare patch.

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>

Thanks folks:
        348 Benjamin Kaduk
        317 Christian Brueffer
        254 Erik Tews
        253 Erik Tews
        219 Carl Mehner
        155 (ghost)
        95 mancha
        51 DominikNeubauer

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>

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

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

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

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

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

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

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

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

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

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

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

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

Note: some of the RFC4279 ciphersuites were originally part of PR#2464.

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

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

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

Move PSK premaster secret algorithm to ssl_generate_master secret so
existing key exchange code can be used and modified slightly to add
the PSK wrapping structure.

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

For SHA384 PRF PSK ciphersuites we have to switch to default PRF for
TLS < 1.2

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

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

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

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

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

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

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

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

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

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

The DTLS code is supposed to drop packets if we try to write them out but
the underlying BIO write buffers are full. ssl3_write_pending() contains
an incorrect test for DTLS that controls this. The test only checks for
DTLS1 so DTLS1.2 does not correctly clear the internal OpenSSL buffer which
can later cause an assert to be hit. This commit changes the test to cover
all DTLS versions.

RT#3967

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

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

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

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

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

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

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

The function SSL_set_session_ticket_ext sets the ticket data to be sent in
the ClientHello. This is useful for EAP-FAST. This commit adds a test to
ensure that when this function is called the expected ticket data actually
appears in the ClientHello.

Reviewed-by: Viktor Dukhovni <viktor@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: Rich Salz <rsalz@openssl.org>