If BN_rand is called with |bits| set to 1 and |top| set to 1 then a 1 byte
buffer overflow can occur. There are no such instances within the OpenSSL at
the moment.

Thanks to Mateusz Kocielski (LogicalTrust), Marek Kroemeke, Filip Palian for
discovering and reporting this issue.

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

The functions BN_rshift and BN_lshift shift their arguments to the right or
left by a specified number of bits. Unpredicatable results (including
crashes) can occur if a negative number is supplied for the shift value.

Thanks to Mateusz Kocielski (LogicalTrust), Marek Kroemeke and Filip Palian
for discovering and reporting this issue.

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 7cc18d81)

Conflicts:
	crypto/bn/bn.h
	crypto/bn/bn_err.c

If a client receives a bad hello request in DTLS then the alert is not
sent correctly.

RT#2801

Signed-off-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 4dc1aa04)

Add documentation for the -no_alt_chains option for various apps, as well as the X509_V_FLAG_NO_ALT_CHAINS flag.

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>

Conflicts:
	doc/apps/cms.pod
	doc/apps/ocsp.pod
	doc/apps/s_client.pod
	doc/apps/s_server.pod
	doc/apps/smime.pod
	doc/apps/verify.pod

Add -no_alt_chains option to apps to implement the new X509_V_FLAG_NO_ALT_CHAINS flag. Using this option means that when building certificate chains, the first chain found will be the one used. Without this flag, if the first chain found is not trusted then we will keep looking to see if we can build an alternative chain instead.

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>

Conflicts:
	apps/cms.c
	apps/ocsp.c
	apps/s_client.c
	apps/s_server.c
	apps/smime.c
	apps/verify.c

Add flag to inhibit checking for alternate certificate chains. Setting this behaviour will force behaviour as per previous versions of OpenSSL

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>

In certain situations the server provided certificate chain may no longer be valid. However the issuer of the leaf, or some intermediate cert is in fact in the trust store.

When building a trust chain if the first attempt fails, then try to see if
alternate chains could be constructed that are trusted.

RT3637
RT3621

Reviewed-by: Kurt Roeckx <kurt@roeckx.be>

40 bit ciphers are limited to 512 bit RSA, 56 bit ciphers to 1024 bit.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit ac38115c)

Since the client has no way of communicating her supported parameter
range to the server, connections to servers that choose weak DH will
simply fail.

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

- Do not advise generation of DH parameters with dsaparam to save
computation time.
- Promote use of custom parameters more, and explicitly forbid use of
built-in parameters weaker than 2048 bits.
- Advise the callback to ignore <keylength> - it is currently called
with 1024 bits, but this value can and should be safely ignored by
servers.

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

The default bitlength is now 2048. Also clarify that either the number
of bits or the generator must be present:

$ openssl dhparam -2
and
$ openssl dhparam 2048
generate parameters but
$ openssl dhparam
does not.

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

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

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

Signed-off-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Signed-off-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 00d565cf)

Backport old patch to make it work in mixture of perls for Windows.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Cherry-picked from 7bb98eee

(cherry picked from commit 051b41df)

The big "don't check for NULL" cleanup requires backporting some
of the lowest-level functions to actually do nothing if NULL is
given.  This will make it easier to backport fixes to release
branches, where master assumes those lower-level functions are "safe"

This commit addresses those tickets: 3798 3799 3801.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit f34b095f)

The function obj_cmp() (file crypto/objects/obj_dat.c) can in some
situations call memcmp() with a null pointer and a zero length.

This is invalid behaviour. When compiling openssl with undefined
behaviour sanitizer (add -fsanitize=undefined to compile flags) this
can be seen. One example that triggers this behaviour is the pkcs7
command (but there are others, e.g. I've seen it with the timestamp
function):
apps/openssl pkcs7 -in test/testp7.pem

What happens is that obj_cmp takes objects of the type ASN1_OBJECT and
passes their ->data pointer to memcmp. Zero-sized ASN1_OBJECT
structures can have a null pointer as data.

RT#3816

Signed-off-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 2b8dc08b)

Currently we set change_cipher_spec_ok to 1 before calling
ssl3_get_cert_verify(). This is because this message is optional and if it
is not sent then the next thing we would expect to get is the CCS. However,
although it is optional, we do actually know whether we should be receiving
one in advance. If we have received a client cert then we should expect
a CertificateVerify message. By the time we get to this point we will
already have bombed out if we didn't get a Certificate when we should have
done, so it is safe just to check whether |peer| is NULL or not. If it is
we won't get a CertificateVerify, otherwise we will. Therefore we should
change the logic so that we only attempt to get the CertificateVerify if
we are expecting one, and not allow a CCS in this scenario.

Whilst this is good practice for TLS it is even more important for DTLS.
In DTLS messages can be lost. Therefore we may be in a situation where a
CertificateVerify message does not arrive even though one was sent. In that
case the next message the server will receive will be the CCS. This could
also happen if messages get re-ordered in-flight. In DTLS if
|change_cipher_spec_ok| is not set and a CCS is received it is ignored.
However if |change_cipher_spec_ok| *is* set then a CCS arrival will
immediately move the server into the next epoch. Any messages arriving for
the previous epoch will be ignored. This means that, in this scenario, the
handshake can never complete. The client will attempt to retransmit
missing messages, but the server will ignore them because they are the wrong
epoch. The server meanwhile will still be waiting for the CertificateVerify
which is never going to arrive.

RT#2958

Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit a0bd6493)

Matt's note: I added a call to X509V3err to Kurt's original patch.

RT#3840

Signed-off-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 344c271e)

clang says: "s_cb.c:958:9: error: implicitly declaring library function
'memcpy'"

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 8f744cce)

Conflicts:
	apps/s_cb.c

If sk_SSL_CIPHER_new_null() returns NULL then ssl_bytes_to_cipher_list()
should also return NULL.

Based on an original patch by mrpre <mrpre@163.com>.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 14def5f5)

Ensure all fatal errors transition into the new error state for DTLS.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit cefc9391)

Conflicts:
	ssl/d1_srvr.c

Conflicts:
	ssl/d1_srvr.c

Ensure all fatal errors transition into the new error state on the client
side.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit cc273a93)

Conflicts:
	ssl/s3_clnt.c

Conflicts:
	ssl/s3_clnt.c

Ensure all fatal errors transition into the new error state on the server
side.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit cf9b0b6f)

Conflicts:
	ssl/s3_srvr.c

Reusing an SSL object when it has encountered a fatal error can
have bad consequences. This is a bug in application code not libssl
but libssl should be more forgiving and not crash.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit a89db885)

Conflicts:
	ssl/s3_srvr.c
	ssl/ssl_stat.c

RT2943 only complains about the incorrect check of -K argument size,
we might as well do the same thing with the -iv argument.

Before this, we only checked that the given argument wouldn't give a
bitstring larger than EVP_MAX_KEY_LENGTH.  we can be more precise and
check against the size of the actual cipher used.

(cherry picked from commit 8920a7cd

)

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

Signed-off-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit bed2edf1)

Signed-off-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
(cherry picked from commit 539ed89f)

The problem occurs in EVP_PKEY_sign() when using RSA with X931 padding.
It is only triggered if the RSA key size is smaller than the digest length.
So with SHA512 you can trigger the overflow with anything less than an RSA
512 bit key. I managed to trigger a 62 byte overflow when using a 16 bit RSA
key. This wasn't sufficient to cause a crash, although your mileage may
vary.

In practice RSA keys of this length are never used and X931 padding is very
rare. Even if someone did use an excessively short RSA key, the chances of
them combining that with a longer digest and X931 padding is very
small. For these reasons I do not believe there is a security implication to
this. Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3
Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit 34166d41)

Add a sanity check to the print_bin function to ensure that the |off|
argument is positive. Thanks to Kevin Wojtysiak (Int3 Solutions) and
Paramjot Oberoi (Int3 Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit 3deeeeb6)

Sanity check the |len| parameter to ensure it is positive. Thanks to Kevin
Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3 Solutions) for
reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit cb0f400b)

The return value is checked for 0. This is currently safe but we should
really check for <= 0 since -1 is frequently used for error conditions.
Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3
Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit c427570e)

Conflicts:
	ssl/ssl_locl.h

Conflicts:
	ssl/ssl_locl.h

For SSLv3 the code assumes that |header_length| > |md_block_size|. Whilst
this is true for all SSLv3 ciphersuites, this fact is far from obvious by
looking at the code. If this were not the case then an integer overflow
would occur, leading to a subsequent buffer overflow. Therefore I have
added an explicit sanity check to ensure header_length is always valid.
Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3
Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit 29b0a15a)

The static function dynamically allocates an output buffer if the output
grows larger than the static buffer that is normally used. The original
logic implied that |currlen| could be greater than |maxlen| which is
incorrect (and if so would cause a buffer overrun). Also the original
logic would call OPENSSL_malloc to create a dynamic buffer equal to the
size of the static buffer, and then immediately call OPENSSL_realloc to
make it bigger, rather than just creating a buffer than was big enough in
the first place. Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot
Oberoi (Int3 Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit 9d9e3774)

There was already a sanity check to ensure the passed buffer length is not
zero. Extend this to ensure that it also not negative. Thanks to Kevin
Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3 Solutions) for
reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit b86d7dca)

The various implementations of EVP_CTRL_AEAD_TLS_AAD expect a buffer of at
least 13 bytes long. Add sanity checks to ensure that the length is at
least that. Also add a new constant (EVP_AEAD_TLS1_AAD_LEN) to evp.h to
represent this length. Thanks to Kevin Wojtysiak (Int3 Solutions) and
Paramjot Oberoi (Int3 Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit c8269881)

Conflicts:
	ssl/record/ssl3_record.c

Conflicts:
	apps/speed.c
	crypto/evp/e_aes_cbc_hmac_sha256.c
	crypto/evp/evp.h

Add a sanity check to DES_enc_write to ensure the buffer length provided
is not negative. Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot
Oberoi (Int3 Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit 873fb39f)

Fortify flagged up a problem in n_do_ssl_write() in SSLv2. Analysing the
code I do not believe there is a real problem here. However the logic flows
are complicated enough that a sanity check of |len| is probably worthwhile.

Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3
Solutions) for reporting this issue.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit c5f8cd7b)

The function CRYPTO_strdup (aka OPENSSL_strdup) fails to check the return
value from CRYPTO_malloc to see if it is NULL before attempting to use it.
This patch adds a NULL check.

RT3786

Signed-off-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 37b0cf936744d9edb99b5dd82cae78a7eac6ad60)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 20d21389c8b6f5b754573ffb6a4dc4f3986f2ca4)