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
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
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
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
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>
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>
In ssl3_send_new_session_ticket the message to be sent is constructed. We
skip adding the length of the session ticket initially, then call
ssl_set_handshake_header, and finally go back and add in the length of the
ticket. Unfortunately, in DTLS, ssl_set_handshake_header also has the side
effect of buffering the message for subsequent retransmission if required.
By adding the ticket length after the call to ssl_set_handshake_header the
message that is buffered is incomplete, causing an invalid message to be
sent on retransmission.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit 4f9fab6bd0)
Conflicts:
ssl/s3_srvr.c
In DTLS, immediately prior to epoch change, the write_sequence is supposed
to be stored in s->d1->last_write_sequence. The write_sequence is then reset
back to 00000000. In the event of retransmits of records from the previous
epoch, the last_write_sequence is restored. This commit fixes a bug in
DTLS1.2 where the write_sequence was being reset before last_write_sequence
was saved, and therefore retransmits are sent with incorrect sequence
numbers.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit d5d0a1cb13)
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)
Don't check that the curve appears in the list of acceptable curves for the
peer, if they didn't send us such a list (RFC 4492 does not require that the
extension be sent).
Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit b79d24101e)
Fix builds config'd with no-ec and no-ec2m. Technically this combination is
redundant - but the fix is straight forward. Fix from OpenWrt.
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
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>
If client auth is used then a server can seg fault in the event of a DHE
cipher being used and a zero length ClientKeyExchange message being sent
by the client. This could be exploited in a DoS attack.
CVE-2015-1787
Reviewed-by: Richard Levitte <levitte@openssl.org>
If a client renegotiates using an invalid signature algorithms extension
it will crash a server with a NULL pointer dereference.
Thanks to David Ramos of Stanford University for reporting this bug.
CVE-2015-0291
Reviewed-by: Tim Hudson <tjh@openssl.org>
Conflicts:
ssl/t1_lib.c
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 that can lead to a segmentation fault. Erorrs processing the initial
ClientHello can trigger this scenario. An example of such an error could
be that a DTLS1.0 only client is attempting to connect to a DTLS1.2 only
server.
CVE-2015-0207
Reviewed-by: Richard Levitte <levitte@openssl.org>
OpenSSL 1.0.2 introduced the "multiblock" performance improvement. This
feature only applies on 64 bit x86 architecture platforms that support AES
NI instructions. A defect in the implementation of "multiblock" can cause
OpenSSL's internal write buffer to become incorrectly set to NULL when
using non-blocking IO. Typically, when the user application is using a
socket BIO for writing, this will only result in a failed connection.
However if some other BIO is used then it is likely that a segmentation
fault will be triggered, thus enabling a potential DoS attack.
CVE-2015-0290
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
Add support for ServerInfo SSL_CONF option and update documentation. This
was wrongly omitted from the 1.0.2 release.
Reviewed-by: Richard Levitte <levitte@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)
If SSL_check_chain is called with a NULL X509 object or a NULL EVP_PKEY
or the type of the public key is unrecognised then the local variable
|cpk| in tls1_check_chain does not get initialised. Subsequently an
attempt is made to deref it (after the "end" label), and a seg fault will
result.
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
(cherry picked from commit d813f9eb38)
Ensure all malloc failures return -1.
Reported by Adam Langley (Google).
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 06c6a2b4a3)
Fix security issue where under certain conditions a client can complete a
handshake with an unseeded PRNG. The conditions are:
- Client is on a platform where the PRNG has not been seeded, and the
user has not seeded manually
- A protocol specific client method version has been used (i.e. not
SSL_client_methodv23)
- A ciphersuite is used that does not require additional random data
from the PRNG beyond the initial ClientHello client random
(e.g. PSK-RC4-SHA)
If the handshake succeeds then the client random that has been used will
have been generated from a PRNG with insufficient entropy and therefore
the output may be predictable.
For example using the following command with an unseeded openssl will
succeed on an unpatched platform:
openssl s_client -psk 1a2b3c4d -tls1_2 -cipher PSK-RC4-SHA
CVE-2015-0285
Reviewed-by: Richard Levitte <levitte@openssl.org>
(cherry picked from commit e1b568dd24)
Since commit 741c9959 ("DTLS revision."), we put the wrong protocol
version into our ClientHello for DTLS1_BAD_VER. The old DTLS
code which used ssl->version was replaced by the more generic SSL3 code
which uses ssl->client_version. The Cisco ASA no longer likes our
ClientHello.
RT#3711
Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit f7683aaf36)
Commit 9cf0f187 in HEAD, and 68039af3 in 1.0.2, removed a version check
from dtls1_buffer_message() which was needed to distinguish between DTLS
1.x and Cisco's pre-standard version of DTLS (DTLS1_BAD_VER).
Based on an original patch by David Woodhouse <dwmw2@infradead.org>
RT#3703
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 5178a16c43)
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)
Miscellaneous unchecked malloc fixes. Also fixed some mem leaks on error
paths as I spotted them along the way.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 918bb86529)
Conflicts:
crypto/bio/bss_dgram.c
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
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
