During certificate verfification, OpenSSL will attempt to find an
alternative certificate chain if the first attempt to build such a chain
fails. An error in the implementation of this logic can mean that an
attacker could cause certain checks on untrusted certificates to be
bypassed, such as the CA flag, enabling them to use a valid leaf
certificate to act as a CA and "issue" an invalid certificate.

This occurs where at least one cert is added to the first chain from the
trust store, but that chain still ends up being untrusted. In that case
ctx->last_untrusted is decremented in error.

Patch provided by the BoringSSL project.

CVE-2015-1793

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

In CCM mode don't require a tag before initialising decrypt: this allows
the tag length to be set without requiring the tag.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 9cca7be1)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 5727582c)

The PSK identity hint should be stored in the SSL_SESSION structure
and not in the parent context (which will overwrite values used
by other SSL structures with the same SSL_CTX).

Use BUF_strndup when copying identity as it may not be null terminated.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 3c66a669)

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 5fced239)

PR#3923

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit ffbf304d)

Typo in local variable name; introduced by previous fix.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit cc3f3fc2)

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 75ba5c58)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 8ca96efd)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit d62c98c8)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 96462695)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 7a1789d2)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit f4c73bfe)

Conflicts:
	crypto/threads/mttest.c

More fprintf()s and printf()s to turn into BIO calls.

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

Construct bio_err and bio_stdout from file handles instead of FILE
pointers, since the latter might not be implemented (when OPENSSL_NO_STDIO
is defined).
Convert all output to use BIO_printf.
Change lh_foo to lh_SSL_SESSION_foo.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit bb8abd67)

Conflicts:
	crypto/threads/mttest.c

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 5c78e183)

Conflicts:
	crypto/threads/mttest.c

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit a3f92865)

Backport to 1.0.1 and 1.0.2 to fix RT 3905

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 8e6bb999)

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit b4f0d1a4)

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 30cf9178)

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

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

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

It is valid for an extension block to be present in a ClientHello, but to
be of zero length.

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

Recent HMAC changes broke ABI compatibility due to a new field in HMAC_CTX.
This backs that change out, and does it a different way.

Thanks to Timo Teras for the concept.

Conflicts:
	crypto/hmac/hmac.c

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

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

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

CVE-2015-1788

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 4924b37e)

Updates to CHANGES and NEWS to take account of the latest security fixes.

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

CVE-2015-1790

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

Also tighten X509_cmp_time to reject more than three fractional
seconds in the time; and to reject trailing garbage after the offset.

CVE-2015-1789

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

Fix loop in do_free_upto if cmsbio is NULL: this will happen when attempting
to verify and a digest is not recognised. Reported by Johannes Bauer.

CVE-2015-1792

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

$(PROGS) was mistakenly removed, adding it back.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 5ef5b9ff)

Fix error handling in ssl_session_dup, as well as incorrect setting up of
the session ticket. Follow on from CVE-2015-1791.

Thanks to LibreSSL project for reporting these issues.

Conflicts:
	ssl/ssl_sess.c

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

Reviewed-by: Rich Salz <rsalz@openssl.org>
MR #838

(cherry picked from commit 57e477b9)

Reviewed-by: Rich Salz <rsalz@openssl.org>
MR #838

(cherry picked from commit 39a298a1)

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: Tim Hudson <tjh@openssl.org>

In the event of an error in the HMAC function, leaks can occur because the
HMAC_CTX does not get cleaned up.

Thanks to the BoringSSL project for reporting this issue.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit e43a13c8)

The function EC_POINT_is_on_curve does not return a boolean value.
It returns 1 if the point is on the curve, 0 if it is not, and -1
on error. Many usages within OpenSSL were incorrectly using this
function and therefore not correctly handling error conditions.

With thanks to the Open Crypto Audit Project for reporting this issue.

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 68886be7)

This adds additional checks to the processing of extensions in a ClientHello
to ensure that either no extensions are present, or if they are then they
take up the exact amount of space expected.

With thanks to the Open Crypto Audit Project for reporting this issue.

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

Conflicts:
	ssl/t1_lib.c