The internal SRP function t_fromb64() converts from base64 to binary. It
does not validate that the size of the destination is sufficiently large -
that is up to the callers. In some places there was such a check, but not
in others.

Add an argument to t_fromb64() to provide the size of the destination
buffer and validate that we don't write too much data. Also add some sanity
checks to the callers where appropriate.

With thanks to Shi Lei for reporting this issue.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 73f0df83)

A peer continually sending unrecognised warning alerts could mean that we
make no progress on a connection. We should abort rather than continuing if
we receive an unrecognised warning alert.

Thanks to Shi Lei for reporting this issue.

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

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

Backport leak fix from master branch.

Thanks to Shi Lei for reporting this bug.

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

Reviewed-by: Andy Polyakov <appro@openssl.org>

VMS sets that errno when the device part of a file spec is malformed
or a logical name that doesn't exist.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit e82e2186)

Some hardware devices don't provide the public EC_POINT data. The only
way for X509_check_private_key() to validate that the key matches a
given certificate is to actually perform a sign operation and then
verify it using the public key in the certificate.

Maybe that can come later, as discussed in issue 1532. But for now let's
at least make it fail gracefully and not crash.

GH: 1532

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1547)
(cherry picked from commit 92ed7fa5)

Never output -0; make "negative zero" an impossibility.
Do better checking on BN_rand top/bottom requirements and #bits.
Update doc.
Ignoring trailing garbage in BN_asc2bn.

Port this commit from boringSSL: https://boringssl.googlesource.com/boringssl/+/899b9b19a4cd3fe526aaf5047ab9234cdca19f7d%5E!/


        Ensure |BN_div| never gives negative zero in the no_branch code.

        Have |bn_correct_top| fix |bn->neg| if the input is zero so that we
        don't have negative zeros lying around.

        Thanks to Brian Smith for noticing.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 01c09f9f)
(Some manual work required)

crypto/bn/*: x86[_64] division instruction doesn't handle constants, change constraint from 'g' to 'r'.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 68b4a6e9)

The function tls_construct_cert_status() is called by both TLS and DTLS
code. However it only ever constructed a TLS message header for the message
which obviously failed in DTLS.

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

OPENSSL_cleanse() does not validate its input parameter for NULL so
SRP_create_verifier() should do so instead. Otherwise a segfault will
result.

Alternative solution to GitHub PR#1006

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

The definition of STITCHED_CALL relies on OPENSSL_NO_ASM.  However,
when a configuration simply lacks the assembler implementation for RC4
(which is where we have implemented the stitched call), OPENSSL_NO_ASM
isn't implemented.  Better, then, to rely on specific macros that
indicated that RC4 (and MD5) are implemented in assembler.

For this to work properly, we must also make sure Configure adds the
definition of RC4_ASM among the C flags.

(partly cherry picked from commit 216e8d91

)

Reviewed-by: Andy Polyakov <appro@openssl.org>

Fix a possible leak on NETSCAPE_SPKI_verify failure.

Backport of 0517538d
Backport of f6c006ea



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

(Modified for 1.0.2 by adding selected PACKET_xx() functions and PRF, and
subsequent cleanup from commit eb633d03

)

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 40425899200a3dea9ec3684d3eb80bcf50c99baf)

Baroque, almost uncommented code triggers behaviour which is undefined
by the C standard. You might quite reasonably not care that the code was
broken on ones-complement machines, but if we support a ubsan build then
we need to at least pretend to care.

It looks like the special-case code for 64-bit big-endian is going to
behave differently (and wrongly) on wrap-around, because it treats the
values as signed. That seems wrong, and allows replay and other attacks.
Surely you need to renegotiate and start a new epoch rather than
wrapping around to sequence number zero again?

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 2e94723c)

Commit d8e8590e

 ("Fix missing return value checks in SCTP") made the
DTLS handshake fail, even for non-SCTP connections, if
SSL_export_keying_material() fails. Which it does, for DTLS1_BAD_VER.

Apply the trivial fix to make it succeed, since there's no real reason
why it shouldn't even though we never need it.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit c8a18468)

This also fixes no-tls which is an alias for no-tls1 in 1.0.2 (it is not
possible to do no-tls1_1 or no-tls1_2 in 1.0.2).

Because it is not possible to disable TLS1.1 or TLS1.2 it no longer follows
that disabling TLS1.0 should force the disabling of tlsext.

Also a few missing ifdef guards.

GitHub Iusse#935

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

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit d3034d31)

RT#4625

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit e3057a57)

Addition was not preserving inputs' property of being fully reduced.

Thanks to Brian Smith for reporting this.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit b62b2454)

Sessions are stored on the session_ctx, which doesn't change after
SSL_set_SSL_CTX().

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

Thanks to Shi Lei for reporting this issue.

CVE-2016-6303

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 55d83bf7)

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Use a ciphersuite in dtlstest that is not affected by no-* options.
Backport of commit fe34735c

.

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

If a ticket callback changes the HMAC digest to SHA512 the existing
sanity checks are not sufficient and an attacker could perform a DoS
attack with a malformed ticket. Add additional checks based on
HMAC size.

Thanks to Shi Lei for reporting this bug.

CVE-2016-6302

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

We don't really have a mechanism to include other object files into a given
test program.  For now, a simple hack in mk1mf.pl will do.

RT#4653

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

a03f81f4

 added a malloc failure check to
EVP_PKEY_keygen, but there already was one.

Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Rich Salz <rsalz@openssl.org>

GH: #1473

Fix an off by one error in the overflow check added by 07bed46f


("Check for errors in BN_bn2dec()").

Reviewed-by: Stephen Henson <steve@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 099e2968)

Also, re-organize RSA check to use goto err.
Try all checks, not just stopping at first (via Richard Levitte)

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 464d59a5)

Most of the time, this isn't strictly needed.  However, in the default
extern model (called relaxed refdef), symbols are treated as weak
common objects unless they are initialised.  The librarian doesn't
include weak symbols in the (static) libraries, which renders them
invisible when linking a program with said those libraries, which is a
problem at times.

Using the strict refdef model is much more like standard C on all
other platforms, and thereby avoid the issues that come with the
relaxed refdef model.

Note: this doesn't apply to VAX C.  It's possible that this will make
OpenSSL building with VAX C difficult some time in the future if it
isn't already.  However, VAX C is a very old compiler that we don't
expect to see too often, as DEC C (a.k.a VMS C) should have replaced
it a long time ago.

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

Some builds fail otherwise.

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

The following would fail, or rather, freeze:

    openssl genrsa -out rsa2048.pem 2048
    openssl req -x509 -key rsa2048.pem -keyform PEM -out cert.pem

In that case, the second command wants to read a certificate request
from stdin, because -x509 wasn't fully flagged as being for creating
something new.  This changes makes it fully flagged.

RT#4655

Reviewed-by: Andy Polyakov <appro@openssl.org>

Original strategy for page-walking was adjust stack pointer and then
touch pages in order. This kind of asks for double-fault, because
if touch fails, then signal will be delivered to frame above adjusted
stack pointer. But touching pages prior adjusting stack pointer would
upset valgrind. As compromise let's adjust stack pointer in pages,
touching top of the stack. This still asks for double-fault, but at
least prevents corruption of neighbour stack if allocation is to
overstep the guard page.

Also omit predict-non-taken hints as they reportedly trigger illegal
instructions in some VM setups.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 3ba1ef82)

In mempacket_test_read(), we've already fetched the top value of the
stack, so when we shift the stack, we don't care for the value.  The
compiler needs to be told, or it will complain harshly when we tell it
to be picky.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 1c288878)

Follow on from CVE-2016-2179

The investigation and analysis of CVE-2016-2179 highlighted a related flaw.

This commit fixes a security "near miss" in the buffered message handling
code. Ultimately this is not currently believed to be exploitable due to
the reasons outlined below, and therefore there is no CVE for this on its
own.

The issue this commit fixes is a MITM attack where the attacker can inject
a Finished message into the handshake. In the description below it is
assumed that the attacker injects the Finished message for the server to
receive it. The attack could work equally well the other way around (i.e
where the client receives the injected Finished message).

The MITM requires the following capabilities:
- The ability to manipulate the MTU that the client selects such that it
is small enough for the client to fragment Finished messages.
- The ability to selectively drop and modify records sent from the client
- The ability to inject its own records a...

DTLS can handle out of order record delivery. Additionally since
handshake messages can be bigger than will fit into a single packet, the
messages can be fragmented across multiple records (as with normal TLS).
That means that the messages can arrive mixed up, and we have to
reassemble them. We keep a queue of buffered messages that are "from the
future", i.e. messages we're not ready to deal with yet but have arrived
early. The messages held there may not be full yet - they could be one
or more fragments that are still in the process of being reassembled.

The code assumes that we will eventually complete the reassembly and
when that occurs the complete message is removed from the queue at the
point that we need to use it.

However, DTLS is also tolerant of packet loss. To get around that DTLS
messages can be retransmitted. If we receive a full (non-fragmented)
message from the peer after previously having received a fragment of
that message, then we ignore the message in the queue and just use the
non-fragmented version. At that point the queued message will never get
removed.

Additionally the peer could send "future" messages that we never get to
in order to complete the handshake. Each message has a sequence number
(starting from 0). We will accept a message fragment for the current
message sequence number, or for any sequence up to 10 into the future.
However if the Finished message has a sequence number of 2, anything
greater than that in the queue is just left there.

So, in those two ways we can end up with "orphaned" data in the queue
that will never get removed - except when the connection is closed. At
that point all the queues are flushed.

An attacker could seek to exploit this by filling up the queues with
lots of large messages that are never going to be used in order to
attempt a DoS by memory exhaustion.

I will assume that we are only concerned with servers here. It does not
seem reasonable to be concerned about a memory exhaustion attack on a
client. They are unlikely to process enough connections for this to be
an issue.

A "long" handshake with many messages might be 5 messages long (in the
incoming direction), e.g. ClientHello, Certificate, ClientKeyExchange,
CertificateVerify, Finished. So this would be message sequence numbers 0
to 4. Additionally we can buffer up to 10 messages in the future.
Therefore the maximum number of messages that an attacker could send
that could get orphaned would typically be 15.

The maximum size that a DTLS message is allowed to be is defined by
max_cert_list, which by default is 100k. Therefore the maximum amount of
"orphaned" memory per connection is 1500k.

Message sequence numbers get reset after the Finished message, so
renegotiation will not extend the maximum number of messages that can be
orphaned per connection.

As noted above, the queues do get cleared when the connection is closed.
Therefore in order to mount an effective attack, an attacker would have
to open many simultaneous connections.

Issue reported by Quan Luo.

CVE-2016-2179

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

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

Thanks to Brian Smith for reporting this.

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

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

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