Some extension handling functions were passing in a pointer to the start
of the data, plus the length in order to calculate the end, rather than
just passing in the end to start with. This change makes things a little
more readable.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Conflicts:
ssl/s3_srvr.c
ssl/ssl_locl.h
ssl/t1_lib.c
RFC 5077 section 3.3 says: If the server determines that it does not
want to include a ticket after it has included the SessionTicket
extension in the ServerHello, then it sends a zero-length ticket in the
NewSessionTicket handshake message.
Previously the client would fail upon attempting to allocate a
zero-length buffer. Now, we have the client ignore the empty ticket and
keep the existing session.
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 21b538d616)
Commit f0348c842e introduced a problem with session resumption. The
version for the session is fixed when the session is created. By moving
the creation of the session earlier in the process the version is fixed
*before* version negotiation has completed when processing the ServerHello
on the client side. This fix updates the session version after version neg
has completed.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit dc0c888811)
Builds using no-tlsext in 1.0.0 and 0.9.8 are broken. This commit fixes the
issue. The same commit is applied to 1.0.1 and 1.0.2 branches for code
consistency. However this commit will not fix no-tlsext in those branches
which have always been broken for other reasons. The commit is not applied
to master at all, because no-tlsext has been completely removed from that
branch.
Based on a patch by Marc Branchaud <marcnarc@xiplink.com>
Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit 9a931208d7)
A DTLS client will abort a handshake if the server attempts to renew the
session ticket. This is caused by a state machine discrepancy between DTLS
and TLS discovered during the state machine rewrite work.
The bug can be demonstrated as follows:
Start a DTLS s_server instance:
openssl s_server -dtls
Start a client and obtain a session but no ticket:
openssl s_client -dtls -sess_out session.pem -no_ticket
Now start a client reusing the session, but allow a ticket:
openssl s_client -dtls -sess_in session.pem
The client will abort the handshake.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit ee4ffd6fcc)
Conflicts:
ssl/d1_clnt.c
When config'd with "sctp" running "make test" causes a seg fault. This is
actually due to the way ssltest works - it dives under the covers and frees
up BIOs manually and so some BIOs are NULL when the SCTP code does not
expect it. The simplest fix is just to add some sanity checks to make sure
the BIOs aren't NULL before we use them.
This problem occurs in master and 1.0.2. The fix has also been applied to
1.0.1 to keep the code in sync.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit f75d5171be)
There are some missing return value checks in the SCTP code. In master this
was causing a compilation failure when config'd with
"--strict-warnings sctp".
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit d8e8590ed9)
If a client receives a ServerKeyExchange for an anon DH ciphersuite with the
value of p set to 0 then a seg fault can occur. This commits adds a test to
reject p, g and pub key parameters that have a 0 value (in accordance with
RFC 5246)
The security vulnerability only affects master and 1.0.2, but the fix is
additionally applied to 1.0.1 for additional confidence.
CVE-2015-1794
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
The function SSL_set_session_ticket_ext can be used to set custom session
ticket data passed in the initial ClientHello. This can be particularly
useful for EAP-FAST. However, when using SSLv23_method, the session does
not get created until the ServerHello has been received. The extension code
will only add the SessionTicket data to the ClientHello if a session already
exists. Therefore SSL_set_session_ticket_ext has no impact when used in
conjunction with SSLv23_method. The solution is to simply create the session
during creation of the ClientHello instead of waiting for the ServerHello.
This commit fixes the test failure introduced by the previous commit.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
The function SSL_set_session_ticket_ext sets the ticket data to be sent in
the ClientHello. This is useful for EAP-FAST. This commit adds a test to
ensure that when this function is called the expected ticket data actually
appears in the ClientHello.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
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 3c66a669df)
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>
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>
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>
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
The fix for CVE-2015-1791 introduced an error in ssl_session_dup for
Kerberos.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit dcad51bc13)
Remove a comment that suggested further clean up was required.
DH_free() performs the necessary cleanup.
With thanks to the Open Crypto Audit Project for reporting this issue.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit f3d889523e)
Ensure OPENSSL_cleanse() is called on the premaster secret value calculated for GOST.
With thanks to the Open Crypto Audit Project for reporting this issue.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit b7ee4815f2)
Conflicts:
ssl/s3_srvr.c
Ensure the Kerberos pre-master secret has OPENSSL_cleanse called on it.
With thanks to the Open Crypto Audit Project for reporting this issue.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 4e3dbe37ca)
If a NewSessionTicket is received by a multi-threaded client when
attempting to reuse a previous ticket then a race condition can occur
potentially leading to a double free of the ticket data.
CVE-2015-1791
This also fixes RT#3808 where a session ID is changed for a session already
in the client session cache. Since the session ID is the key to the cache
this breaks the cache access.
Parts of this patch were inspired by this Akamai change:
c0bf69a791
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 27c76b9b80)
Conflicts:
ssl/ssl.h
ssl/ssl_err.c
This is a backport of commit e83ee04bb7 from
the master branch (and this has also been applied to 1.0.2). In 1.0.2 this
was CVE-2015-0207. For other branches there is no known security issue, but
this is being backported as a precautionary measure.
The DTLSv1_listen function is intended to be stateless and processes
the initial ClientHello from many peers. It is common for user code to
loop over the call to DTLSv1_listen until a valid ClientHello is received
with an associated cookie. A defect in the implementation of DTLSv1_listen
means that state is preserved in the SSL object from one invokation to the
next.
Reviewed-by: Richard Levitte <levitte@openssl.org>
dtls1_get_message has an |mt| variable which is the type of the message that
is being requested. If it is negative then any message type is allowed.
However the value of |mt| is not checked in one of the main code paths, so a
peer can send a message of a completely different type and it will be
processed as if it was the message type that we were expecting. This has
very little practical consequences because the current behaviour will still
fail when the format of the message isn't as expected.
Reviewed-by: Andy Polyakov <appro@openssl.org>
(cherry picked from commit 8c2b1d872b)
The size of the SRP extension can never be negative (the variable
|size| is unsigned). Therefore don't check if it is less than zero.
RT#3862
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 9c89d29083)
If the record received is for a version that we don't support, previously we
were sending an alert back. However if the incoming record already looks
like an alert then probably we shouldn't do that. So suppress an outgoing
alert if it looks like we've got one incoming.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
We had updates of certain header files in both Makefile.org and the
Makefile in the directory the header file lived in. This is error
prone and also sometimes generates slightly different results (usually
just a comment that differs) depending on which way the update was
done.
This removes the file update targets from the top level Makefile, adds
an update: target in all Makefiles and has it depend on the depend: or
local_depend: targets, whichever is appropriate, so we don't get a
double run through the whole file tree.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 0f539dc1a2)
Conflicts:
Makefile.org
apps/Makefile
test/Makefile
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 4dc1aa0436)
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 ac38115c1a)
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>
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 a0bd649336)
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 14def5f537)
Ensure all fatal errors transition into the new error state for DTLS.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit cefc93910c)
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 cc273a9361)
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 cf9b0b6fb2)
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 a89db885e0)
Conflicts:
ssl/s3_srvr.c
ssl/ssl_stat.c
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 cb0f400b0c)
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 c427570e50)
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 29b0a15a48)
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 c826988109)
Conflicts:
ssl/record/ssl3_record.c
Conflicts:
apps/speed.c
crypto/evp/e_aes_cbc_hmac_sha256.c
crypto/evp/evp.h
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 c5f8cd7bc6)
EAP-FAST session resumption relies on handshake message lookahead
to determine server intentions. Commits
980bc1ec61
and
7b3ba508af
removed the lookahead so broke session resumption.
This change partially reverts the commits and brings the lookahead back
in reduced capacity for TLS + EAP-FAST only. Since EAP-FAST does not
support regular session tickets, the lookahead now only checks for a
Finished message.
Regular handshakes are unaffected by this change.
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 6e3d015363)
A 0-length ciphers list is never permitted. The old code only used to
reject an empty ciphers list for connections with a session ID. It
would later error out on a NULL structure, so this change just moves
the alert closer to the problem source.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 3ae91cfb32)
If OpenSSL is configured with no-tlsext then ssl_get_prev_session can read
past the end of the ClientHello message if the session_id length in the
ClientHello is invalid. This should not cause any security issues since the
underlying buffer is 16k in size. It should never be possible to overrun by
that many bytes.
This is probably made redundant by the previous commit - but you can never be
too careful.
With thanks to Qinghao Tang for reporting this issue.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit 5e0a80c1c9)
The ClientHello processing is insufficiently rigorous in its checks to make
sure that we don't read past the end of the message. This does not have
security implications due to the size of the underlying buffer - but still
needs to be fixed.
With thanks to Qinghao Tang for reporting this issue.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit c9642eb1ff79a30e2c7632ef8267cc34cc2b0d79)
There is no indication that the timing differences are exploitable in
OpenSSL, and indeed there is some indication (Usenix '14) that they
are too small to be exploitable. Nevertheless, be careful and apply
the same countermeasures as in s3_srvr.c
Thanks to Nimrod Aviram, Sebastian Schinzel and Yuval Shavitt for
reporting this issue.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit ae50d82700)
Ensure all calls to RAND_bytes and RAND_pseudo_bytes have their return
value checked correctly
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 8f8e4e4f52)
Conflicts:
crypto/evp/e_des3.c
The certificate already contains the DH parameters in that case.
ssl3_send_server_key_exchange() would fail in that case anyway.
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 93f1c13619)
Fix some unsigned/signed warnings introduced as part of the fix
for CVE-2015-0293
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
This assert is reachable for servers that support SSLv2 and export ciphers.
Therefore, such servers can be DoSed by sending a specially crafted
SSLv2 CLIENT-MASTER-KEY.
Also fix s2_srvr.c to error out early if the key lengths are malformed.
These lengths are sent unencrypted, so this does not introduce an oracle.
CVE-2015-0293
This issue was discovered by Sean Burford (Google) and Emilia Käsper of
the OpenSSL development team.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
The function tls1_PRF counts the number of digests in use and partitions
security evenly between them. There always needs to be at least one digest
in use, otherwise this is an internal error. Add a sanity check for this.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 668f6f08c6)
Cleanse various intermediate buffers used by the PRF (backported version
from master).
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 35fafc4dbc)
Conflicts:
ssl/s3_enc.c
Ensure all malloc failures return -1.
Reported by Adam Langley (Google).
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 06c6a2b4a3)
They are moved to the COMPLEMENTOFDEFAULT instead.
This also fixes SSLv2 to be part of COMPLEMENTOFDEFAULT.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit f417997a32)
Conflicts:
ssl/ssl_ciph.c
This patch uses warning/fatal constants instead of numbers with comments for
warning/alerts in d1_pkt.c and s3_pkt.c
RT#3725
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit fd865cadcb)
Some Cisco appliances use a pre-standard version number for DTLS. We support
this as DTLS1_BAD_VER within the code.
This change fixes d2i_SSL_SESSION for that DTLS version.
Based on an original patch by David Woodhouse <dwmw2@infradead.org>
RT#3704
Reviewed-by: Tim Hudson <tjh@openssl.org>
Conflicts:
ssl/ssl_asn1.c
Conflicts:
ssl/dtls1.h
Fixed various missing return value checks in ssl3_send_newsession_ticket.
Also a mem leak on error.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Conflicts:
ssl/s3_srvr.c
Conflicts:
ssl/s3_srvr.c
This should be a one off operation (subsequent invokation of the
script should not move them)
This commit is for the 1.0.1 changes
Reviewed-by: Tim Hudson <tjh@openssl.org>
Sometimes it fails to format them very well, and sometimes it corrupts them!
This commit moves some particularly problematic ones.
Conflicts:
crypto/bn/bn.h
crypto/ec/ec_lcl.h
crypto/rsa/rsa.h
demos/engines/ibmca/hw_ibmca.c
ssl/ssl.h
ssl/ssl3.h
Conflicts:
crypto/ec/ec_lcl.h
ssl/tls1.h
Reviewed-by: Tim Hudson <tjh@openssl.org>
indent will not alter them when reformatting comments
(cherry picked from commit 1d97c84351)
Conflicts:
crypto/bn/bn_lcl.h
crypto/bn/bn_prime.c
crypto/engine/eng_all.c
crypto/rc4/rc4_utl.c
crypto/sha/sha.h
ssl/kssl.c
ssl/t1_lib.c
Conflicts:
crypto/rc4/rc4_enc.c
crypto/x509v3/v3_scts.c
crypto/x509v3/v3nametest.c
ssl/d1_both.c
ssl/s3_srvr.c
ssl/ssl.h
ssl/ssl_locl.h
ssl/ssltest.c
ssl/t1_lib.c
Reviewed-by: Tim Hudson <tjh@openssl.org>
ssl3_setup_buffers or pqueue_insert fail. The former will fail if there is a
malloc failure, whilst the latter will fail if attempting to add a duplicate
record to the queue. This should never happen because duplicate records should
be detected and dropped before any attempt to add them to the queue.
Unfortunately records that arrive that are for the next epoch are not being
recorded correctly, and therefore replays are not being detected.
Additionally, these "should not happen" failures that can occur in
dtls1_buffer_record are not being treated as fatal and therefore an attacker
could exploit this by sending repeated replay records for the next epoch,
eventually causing a DoS through memory exhaustion.
Thanks to Chris Mueller for reporting this issue and providing initial
analysis and a patch. Further analysis and the final patch was performed by
Matt Caswell from the OpenSSL development team.
CVE-2015-0206
Reviewed-by: Dr Stephen Henson <steve@openssl.org>
Fix to prevent use of DH client certificates without sending
certificate verify message.
If we've used a client certificate to generate the premaster secret
ssl3_get_client_key_exchange returns 2 and ssl3_get_cert_verify is
never called.
We can only skip the certificate verify message in
ssl3_get_cert_verify if the client didn't send a certificate.
Thanks to Karthikeyan Bhargavan for reporting this issue.
CVE-2015-0205
Reviewed-by: Matt Caswell <matt@openssl.org>
of the crash due to p being NULL. Steve's fix prevents this situation from
occuring - however this is by no means obvious by looking at the code for
dtls1_get_record. This fix just makes things look a bit more sane.
Reviewed-by: Dr Steve Henson <steve@openssl.org>
OpenSSL clients would tolerate temporary RSA keys in non-export
ciphersuites. It also had an option SSL_OP_EPHEMERAL_RSA which
enabled this server side. Remove both options as they are a
protocol violation.
Thanks to Karthikeyan Bhargavan for reporting this issue.
(CVE-2015-0204)
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 4b4c1fcc88)
Conflicts:
doc/ssl/SSL_CTX_set_options.pod
Fix bug where an OpenSSL client would accept a handshake using an
ephemeral ECDH ciphersuites with the server key exchange message omitted.
Thanks to Karthikeyan Bhargavan for reporting this issue.
CVE-2014-3572
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit b15f876964)
When parsing ClientHello clear any existing extension state from
SRP login and SRTP profile.
Thanks to Karthikeyan Bhargavan for reporting this issue.
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 47606dda67)
Conflicts:
ssl/t1_lib.c
From BoringSSL
- Send an alert when the client key exchange isn't correctly formatted.
- Reject overly short RSA ciphertexts to avoid a (benign) out-of-bounds memory access.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 4aecfd4d9f)
