The previous commit inspired a review of all the length checks for the
extension adding code. This adds more robust checks and adds checks where
some were missing previously. The real solution for this is to use WPACKET
which is currently in master - but that cannot be applied to release
branches.

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

The status request extension did not correctly check its length, meaning
that writing the extension could go 2 bytes beyond the buffer size. In
practice this makes little difference because, due to logic in buffer.c the
buffer is actually over allocated by approximately 5k!

Issue reported by Guido Vranken.

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

Providing a spkac file with no default section causes a double free.

Thanks to Brian Carpenter for reporting this issue.

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 229bd124)

A zero return from BIO_read()/BIO_write() could mean that an IO operation
is retryable. A zero return from SSL_read()/SSL_write() means that the
connection has been closed down (either cleanly or not). Therefore we
should not propagate a zero return value from BIO_read()/BIO_write() back
up the stack to SSL_read()/SSL_write(). This could result in a retryable
failure being treated as fatal.

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

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 12a7715e)

A temporary buffer containing g^xy was not cleared in ecdh_compute_key()
before freeing it, so the shared secret was leaked in memory.

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

Unhandled critical CRL extensions were not detected if they appeared
after the handled ones.  (GitHub issue 1757).  Thanks to John Chuah
for reporting this.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1769)

The structure has already been initialized to zero with memset.
See also commit 64b25758

 (remove 0 assignments)

Signed-off-by: Cristian Stoica <cristian.stoica@nxp.com>
CLA: trivial
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1463)

This avoids failures when configuring with --strict-warnings

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1749)

This removes some #ifndef clutter.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1644)

In apps/apps.c, one can set up an engine with setup_engine().
However, we freed the structural reference immediately, which means
that for engines that don't already have a structural reference
somewhere else (because it has registered at least one cipher or digest
algorithm method, and therefore gets a functional reference through the
ENGINE_set_default() call), we end up returning an invalid reference.

Instead, the function release_engine() is added, and called at the end
of the routines that call setup_engine().

Originally, the ENGINE API wasn't designed for this to happen, an
engine had to register at least one algorithm method, and was
especially expected to register the algorithms corresponding to the
key types that could be stored and hidden in hardware.  However, it
turns out that some engines will not register those algorithms with
the ENGINE_set_{algo}, ENGINE_set_cipher or ENGINE_set_digest
functions, as they only want the methods to be used for keys, not as
general crypto accelerator methods.  That may cause ENGINE_set_default()
to do nothing, and no functional reference is therefore made, leading
to a premature deallocation of the engine and it thereby becoming
unavailable when trying to fetch a key.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1644)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1748)

Fixes RT#4699

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1668)

crypto/evp/e_aes.c: Types of inp and out parameters of AES_xts_en/decrypt
functions need to be changed from char to unsigned char to avoid build
error due to -Werror=incompatible-pointer-types.

crypto/aes/asm/aes-s390x.pl: Comments need to reflect the above change.

Signed-off-by: Patrick Steuer <psteuer@mail.de>

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

crypto/s390xcap.c: cryptlib.h needs to be included for OPENSSL_cpuid_setup
function prototype is located there to avoid build error due to
-Werror=missing-prototypes.

Signed-off-by: Patrick Steuer <psteuer@mail.de>

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

These are implemented as macros delegating to `EVP_DigestUpdate`, which
takes a `size_t` as its third argument, not an `unsigned int`.

CLA: trivial

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 8bdce8d1)

If len == 0 in a call to ERR_error_string_n() then we can read beyond the
end of the buffer. Really applications should not be calling this function
with len == 0, but we shouldn't be letting it through either!

Thanks to Agostino Sarubbo for reporting this issue. Agostino's blog on
this issue is available here:
https://blogs.gentoo.org/ago/2016/10/14/openssl-libcrypto-stack-based-buffer-overflow-in-err_error_string_n-err-c/



Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit e5c13615)

The SWEET32 fix moved 3DES from HIGH to MEDIUM, but omitted SSL2.

CLA: trivial
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1683)

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1702)
(cherry picked from commit 7954dced)

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

Before loading a key from an engine, it may need to be initialized.
When done loading the key, we must de-initialize the engine.
(if the engine is already initialized somehow, only the reference
counter will be incremented then decremented)

Reviewed-by: Stephen Henson <steve@openssl.org>
(cherry picked from commit 49e476a5)

This reverts commit 4badd2b3

.
This fails to call ENGINE_finish; an alternate fix is coming.

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

Things like 'openssl s_client' only ever worked with keys from an engine
which provided a default generic method for some key type — because it
called ENGINE_set_default() and that ended up being an implicit
initialisation and functional refcount.

But an engine which doesn't provide generic methods doesn't get
initialised, and then when you try to use it you get an error:

cannot load client certificate private key file from engine
140688147056384:error:26096075:engine routines:ENGINE_load_private_key:not initialised:crypto/engine/eng_pkey.c:66:
unable to load client certificate private key file

cf. https://github.com/OpenSC/libp11/issues/107

 (in which we discover
that engine_pkcs11 *used* to provide generic methods that OpenSSL would
try to use for ephemeral DH keys when negotiating ECDHE cipher suites in
TLS, and that didn't work out very well.)

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1640)

The NEWS file referenced the wrong CVE for 1.0.2

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

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

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

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

Note: this was accidentally omitted from OpenSSL 1.0.2 branch.
Without this fix any attempt to use CRLs will crash.

CVE-2016-7052

Thanks to Bruce Stephens and Thomas Jakobi for reporting this issue.

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

Add a missing ifdef. Same change is already present in master.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1100)

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

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

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

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

Russian GOST ciphersuites are vulnerable to the KCI attack because they use
long-term keys to establish the connection when ssl client authorization is
on. This change brings the GOST implementation into line with the latest
specs in order to avoid the attack. It should not break backwards
compatibility.

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

If a server sent multiple NPN extensions in a single ClientHello then a
mem leak can occur. This will only happen where the client has requested
NPN in the first place. It does not occur during renegotiation. Therefore
the maximum that could be leaked in a single connection with a malicious
server is 64k (the maximum size of the ServerHello extensions section). As
this is client side, only occurs if NPN has been requested and does not
occur during renegotiation this is unlikely to be exploitable.

Issue reported by Shi Lei.

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

A malicious client can send an excessively large OCSP Status Request
extension. If that client continually requests renegotiation,
sending a large OCSP Status Request extension each time, then there will
be unbounded memory growth on the server. This will eventually lead to a
Denial Of Service attack through memory exhaustion. Servers with a
default configuration are vulnerable even if they do not support OCSP.
Builds using the "no-ocsp" build time option are not affected.

I have also checked other extensions to see if they suffer from a similar
problem but I could not find any other issues.

CVE-2016-6304

Issue reported by Shi Lei.

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

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

Certain warning alerts are ignored if they are received. This can mean that
no progress will be made if one peer continually sends those warning alerts.
Implement a count so that we abort the connection if we receive too many.

Issue reported by Shi Lei.

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

Grow TLS/DTLS 16 bytes more than strictly necessary as a precaution against
OOB reads. In most cases this will have no effect because the message buffer
will be large enough already.

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

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