A common idiom in the codebase is:

if (p + len > limit)
{
    return; /* Too long */
}

Where "p" points to some malloc'd data of SIZE bytes and
limit == p + SIZE

"len" here could be from some externally supplied data (e.g. from a TLS
message).

The rules of C pointer arithmetic are such that "p + len" is only well
defined where len <= SIZE. Therefore the above idiom is actually
undefined behaviour.

For example this could cause problems if some malloc implementation
provides an address for "p" such that "p + len" actually overflows for
values of len that are too big and therefore p + len < limit!

Issue reported by Guido Vranken.

CVE-2016-2177

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

Set ctx->error = X509_V_ERR_OUT_OF_MEM when verificaiton cannot
continue due to malloc failure.  Similarly for issuer lookup failures
and caller errors (bad parameters or invalid state).

Also, when X509_verify_cert() returns <= 0 make sure that the
verification status does not remain X509_V_OK, as a last resort set
it it to X509_V_ERR_UNSPECIFIED, just in case some code path returns
an error without setting an appropriate value of ctx->error.

Add new and some missing error codes to X509 error -> SSL alert switch.

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

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

The functions SRP_Calc_client_key() and SRP_Calc_server_key() were
incorrectly returning a valid pointer in the event of error.

Issue reported by Yuan Jochen Kang

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 308ff286)

In the X509 app check that the obtained public key is valid before we
attempt to use it.

Issue reported by Yuan Jochen Kang.

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

Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit c393a5de)

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

RT#3826

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 2b4825d0)

PR#4449

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

(cherry picked from commit b1f8ba4d)

PR#4466

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

(cherry picked from commit 06227924)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 708cf5de)

The default ASN.1 handling can be used for SEED. This also makes
CMS work with SEED.

PR#4504

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit c0aa8c27)

Try to set the ASN.1 parameters for CMS encryption even if the IV
length is zero as the underlying cipher should still set the type.

This will correctly result in errors if an attempt is made to use
an unsupported cipher type.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 3fd60dc4)

Conflicts:
	crypto/cms/cms_enc.c

The name length limit check in x509_name_ex_d2i() includes
the containing structure as well as the actual X509_NAME. This will
cause large CRLs to be rejected.

Fix by limiting the length passed to ASN1_item_ex_d2i() which will
then return an error if the passed X509_NAME exceeds the length.

RT#4531

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 4e0d184a)

RT#4527

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 3340e8bb)

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit b1b3e14f)

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

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

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

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

Only treat an ASN1_ANY type as an integer if it has the V_ASN1_INTEGER
tag: V_ASN1_NEG_INTEGER is an internal only value which is never used
for on the wire encoding.

Thanks to David Benjamin <davidben@google.com> for reporting this bug.

This was found using libFuzzer.

RT#4364 (part)CVE-2016-2108.

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

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

CVE-2016-2107

MR: #2572

A few functions in the recently added EVP_EncodeInit docs don't apply to
the 1.0.x branches.

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

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

With the EVP_EncodeUpdate function it is the caller's responsibility to
determine how big the output buffer should be. The function writes the
amount actually used to |*outl|. However this could go negative with a
sufficiently large value for |inl|. We add a check for this error
condition.

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

An overflow can occur in the EVP_EncodeUpdate function which is used for
Base64 encoding of binary data. If an attacker is able to supply very large
amounts of input data then a length check can overflow resulting in a heap
corruption. Due to the very large amounts of data involved this will most
likely result in a crash.

Internally to OpenSSL the EVP_EncodeUpdate function is primarly used by the
PEM_write_bio* family of functions. These are mainly used within the
OpenSSL command line applications, so any application which processes
data from an untrusted source and outputs it as a PEM file should be
considered vulnerable to this issue.

User applications that call these APIs directly with large amounts of
untrusted data may also be vulnerable.

Issue reported by Guido Vranken.

CVE-2016-2105

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

ASN1 Strings that are over 1024 bytes can cause an overread in
applications using the X509_NAME_oneline() function on EBCDIC systems.
This could result in arbitrary stack data being returned in the buffer.

Issue reported by Guido Vranken.

CVE-2016-2176

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

An overflow can occur in the EVP_EncryptUpdate function. If an attacker is
able to supply very large amounts of input data after a previous call to
EVP_EncryptUpdate with a partial block then a length check can overflow
resulting in a heap corruption.

Following an analysis of all OpenSSL internal usage of the
EVP_EncryptUpdate function all usage is one of two forms.

The first form is like this:
EVP_EncryptInit()
EVP_EncryptUpdate()

i.e. where the EVP_EncryptUpdate() call is known to be the first called
function after an EVP_EncryptInit(), and therefore that specific call
must be safe.

The second form is where the length passed to EVP_EncryptUpdate() can be
seen from the code to be some small value and therefore there is no
possibility of an overflow.

Since all instances are one of these two forms, I believe that there can
be no overflows in internal code due to this problem.

It should be noted that EVP_DecryptUpdate() can call EVP_EncryptUpdate()
in certain code paths. Also EVP_CipherUpdate() is a synonym for
EVP_EncryptUpdate(). Therefore I have checked all instances of these
calls too, and came to the same conclusion, i.e. there are no instances
in internal usage where an overflow could occur.

This could still represent a security issue for end user code that calls
this function directly.

CVE-2016-2106

Issue reported by Guido Vranken.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 3f358213)

Reported by David Benjamin

Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit 05aef4bb)

Issue reported by Guido Vranken.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 64eaf6c9)

Sanity check field lengths and sums to avoid potential overflows and reject
excessively large X509_NAME structures.

Issue reported by Guido Vranken.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 9b08619c)

Conflicts:
	crypto/x509/x509.h
	crypto/x509/x509_err.c

Reject zero length buffers passed to X509_NAME_onelne().

Issue reported by Guido Vranken.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit b33d1141)

This adds an explicit limit to the size of an X509_NAME structure. Some
part of OpenSSL (e.g. TLS) already effectively limit the size due to
restrictions on certificate size.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 295f3a24)

The traditional private key encryption algorithm doesn't function
properly if the IV length of the cipher is zero. These ciphers
(e.g. ECB mode) are not suitable for private key encryption
anyway.

Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit d78df5df)

The i2d_X509() function can return a negative value on error. Therefore
we should make sure we check it.

Issue reported by Yuan Jochen Kang.

Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit 446ba8de)

This causes a compilation failure when using --strict-warnings in 1.0.2
and 1.0.1

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
(cherry picked from commit 0ca67644)

Thanks to Brian Carpenter for finding and reporting this.

Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit 79356a83)

Backport of commits:

        79c7f74d
	bdcd660e



from master.

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

If the ASN.1 BIO is presented with a large length field read it in
chunks of increasing size checking for EOF on each read. This prevents
small files allocating excessive amounts of data.

CVE-2016-2109

Thanks to Brian Carpenter for reporting this issue.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
(cherry picked from commit c6298139)

Free up parsed X509_NAME structure if the CertificateRequest message
contains excess data.

The security impact is considered insignificant. This is a client side
only leak and a large number of connections to malicious servers would
be needed to have a significant impact.

This was found by libFuzzer.

Reviewed-by: Emilia Käsper <emilia@openssl.org>
Reviewed-by: Stephen Henson <steve@openssl.org>
(cherry picked from commit ec66c8c9)