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

if we have a malloc |x = OPENSSL_malloc(...)| sometimes we check |x|
for NULL and sometimes we treat it as a boolean |if(!x) ...|. Standardise
the approach in libssl.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Various enums were introduced as part of the state machine rewrite. As a
matter of style it is preferred for these to be typedefs.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Move some function definitions around within the state machine to make sure
they are in the correct files. Also create a statem_locl.h header for stuff
entirely local to the state machine code and move various definitions into
it.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Pull out the state machine into a separate sub directory. Also moved some
functions which were nothing to do with the state machine but were in state
machine files. Pulled all the SSL_METHOD definitions into one place...most
of those files had very little left in them any more.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Clean up and remove lots of code that is now no longer needed due to the
move to the new state machine.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Move all DTLS client side processing into the new state machine code. A
subsequent commit will clean up the old dead code.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Create a dtls_get_message function similar to the old dtls1_get_message but
in the format required for the new state machine code. The old function will
eventually be deleted in later commits.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

The old implementation of DTLSv1_listen which has now been replaced still
had a few vestiges scattered throughout the code. This commit removes them.
Reviewed-by: NAndy Polyakov <appro@openssl.org>

The existing implementation of DTLSv1_listen() is fundamentally flawed. This
function is used in DTLS solutions to listen for new incoming connections
from DTLS clients. A client will send an initial ClientHello. The server
will respond with a HelloVerifyRequest containing a unique cookie. The
client the responds with a second ClientHello - which this time contains the
cookie.

Once the cookie has been verified then DTLSv1_listen() returns to user code,
which is typically expected to continue the handshake with a call to (for
example) SSL_accept().

Whilst listening for incoming ClientHellos, the underlying BIO is usually in
an unconnected state. Therefore ClientHellos can come in from *any* peer.
The arrival of the first ClientHello without the cookie, and the second one
with it, could be interspersed with other intervening messages from
different clients.

The whole purpose of this mechanism is as a defence against DoS attacks. The
idea is to avoid allocating state on the server until the client has
verified that it is capable of receiving messages at the address it claims
to come from. However the existing DTLSv1_listen() implementation completely
fails to do this. It attempts to super-impose itself on the standard state
machine and reuses all of this code. However the standard state machine
expects to operate in a stateful manner with a single client, and this can
cause various problems.

A second more minor issue is that the return codes from this function are
quite confused, with no distinction made between fatal and non-fatal errors.
Most user code treats all errors as non-fatal, and simply retries the call
to DTLSv1_listen().

This commit completely rewrites the implementation of DTLSv1_listen() and
provides a stand alone implementation that does not rely on the existing
state machine. It also provides more consistent return codes.
Reviewed-by: NAndy Polyakov <appro@openssl.org>

There are many places (nearly 50) where we malloc and then memset.
Add an OPENSSL_zalloc routine to encapsulate that.
(Missed one conversion; thanks Richard)
Also fixes GH328
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

When config'd with "sctp" running "make test" causes a seg fault. This is
actually due to the way ssltest works - it dives under the covers and frees
up BIOs manually and so some BIOs are NULL when the SCTP code does not
expect it. The simplest fix is just to add some sanity checks to make sure
the BIOs aren't NULL before we use them.

This problem occurs in master and 1.0.2. The fix has also been applied to
1.0.1 to keep the code in sync.
Reviewed-by: NTim Hudson <tjh@openssl.org>

The move of CCS into the state machine was causing make errors to fail. This
fixes it.
Reviewed-by: NTim Hudson <tjh@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>

It should not be possible for DTLS message fragments to span multiple
packets. However previously if the message header fitted exactly into one
packet, and the fragment body was in the next packet then this would work.
Obviously this would fail if packets get re-ordered mid-flight.
Reviewed-by: NTim Hudson <tjh@openssl.org>

dtls1_get_message has an |mt| variable which is the type of the message that
is being requested. If it is negative then any message type is allowed.
However the value of |mt| is not checked in one of the main code paths, so a
peer can send a message of a completely different type and it will be
processed as if it was the message type that we were expecting. This has
very little practical consequences because the current behaviour will still
fail when the format of the message isn't as expected.
Reviewed-by: NAndy Polyakov <appro@openssl.org>

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

Just as with the OPENSSL_malloc calls, consistently use sizeof(*ptr)
for memset and memcpy.  Remove needless casts for those functions.
For memset, replace alternative forms of zero with 0.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

For a local variable:
        TYPE *p;
Allocations like this are "risky":
        p = OPENSSL_malloc(sizeof(TYPE));
if the type of p changes, and the malloc call isn't updated, you
could get memory corruption.  Instead do this:
        p = OPENSSL_malloc(sizeof(*p));
Also fixed a few memset() calls that I noticed while doing this.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

After the finale, the "real" final part. :)  Do a recursive grep with
"-B1 -w [a-zA-Z0-9_]*_free" to see if any of the preceeding lines are
an "if NULL" check that can be removed.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Don't check for NULL before calling OPENSSL_free
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Following ANSI C rules, remove the casts from calls to
OPENSSL_malloc and OPENSSL_realloc.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NMatt Caswell <matt@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>

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

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

Ensure RAND_bytes return value is checked correctly, and that we no longer
use RAND_pseudo_bytes.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Ensure that all functions have their return values checked where
appropriate. This covers all functions defined and called from within
libssl.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Commit 9cf0f187 in HEAD, and 68039af3 in 1.0.2, removed a version check
from dtls1_buffer_message() which was needed to distinguish between DTLS
1.x and Cisco's pre-standard version of DTLS (DTLS1_BAD_VER).

Based on an original patch by David Woodhouse <dwmw2@infradead.org>
RT#3703
Reviewed-by: NTim Hudson <tjh@openssl.org>

I left many "#if 0" lines, usually because I thought we would
probably want to revisit them later, or because they provided
some useful internal documentation tips.
Reviewed-by: NAndy Polyakov <appro@openssl.org>

This should be a one off operation (subsequent invokation of the
script should not move them)
Reviewed-by: NTim Hudson <tjh@openssl.org>

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

Sometimes it fails to format them very well, and sometimes it corrupts them!
This commit moves some particularly problematic ones.
Reviewed-by: NTim Hudson <tjh@openssl.org>

indent will not alter them when reformatting comments
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NEmilia Käsper <emilia@openssl.org>

Reviewed-by: NEmilia Käsper <emilia@openssl.org>