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
This should be a one off operation (subsequent invokation of the
script should not move them)
This commit is for the 1.0.2 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
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
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>
(cherry picked from commit 652ff0f4796eecd8729b4690f2076d1c7ccb2862)
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 Stephen 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>
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)
Since SGC has been removed from OpenSSL 1.0.2 the
SSL3_FLAGS_SGC_RESTART_DONE is no longer used. However the #define is
retained for compatibility.
Reviewed-by: Matt Caswell <matt@openssl.org>
MS Server gated cryptography is obsolete and dates from the time of export
restrictions on strong encryption and is only used by ancient versions of
MSIE.
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 63eab8a620)
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 4f605ccb77)
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)
The client_version needs to be preserved for the RSA key exchange.
This change also means that renegotiation will, like TLS, repeat the old
client_version rather than advertise only the final version. (Either way,
version change on renego is not allowed.) This is necessary in TLS to work
around an SChannel bug, but it's not strictly necessary in DTLS.
(From BoringSSL)
Reviewed-by: Emilia Käsper <emilia@openssl.org>
(cherry picked from commit ec1af3c419)
Odd-length lists should be rejected everywhere upon parsing. Nevertheless,
be extra careful and add guards against off-by-one reads.
Also, drive-by replace inexplicable double-negation with an explicit comparison.
Reviewed-by: Matt Caswell <matt@openssl.org>
The Supported Elliptic Curves extension contains a vector of NamedCurves
of 2 bytes each, so the total length must be even. Accepting odd-length
lists was observed to lead to a non-exploitable one-byte out-of-bounds
read in the latest development branches (1.0.2 and master). Released
versions of OpenSSL are not affected.
Thanks to Felix Groebert of the Google Security Team for reporting this issue.
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 33d5ba8629)
we will support then dtls1_do_write can go into an infinite loop. This commit
fixes that.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit d3d9eef316)
at least the minimum or it will fail.
There were some instances in dtls1_query_mtu where the final mtu can end up
being less than the minimum, i.e. where the user has set an mtu manually. This
shouldn't be allowed. Also remove dtls1_guess_mtu that, despite having
logic for guessing an mtu, was actually only ever used to work out the minimum
mtu to use.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 1620a2e49c)
and instead use the value provided by the underlying BIO. Also provide some
new DTLS_CTRLs so that the library user can set the mtu without needing to
know this constant. These new DTLS_CTRLs provide the capability to set the
link level mtu to be used (i.e. including this IP/UDP overhead). The previous
DTLS_CTRLs required the library user to subtract this overhead first.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 59669b6abf)
Conflicts:
ssl/d1_both.c
mtu that we have received is not less than the minimum. If its less it uses the
minimum instead. The second call to query the mtu does not do that, but
instead uses whatever comes back. We have seen an instance in RT#3592 where we
have got an unreasonably small mtu come back. This commit makes both query
checks consistent.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 6abb0d1f8e)
automatically updated, and we should use the one provided instead.
Unfortunately there are a couple of locations where this is not respected.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 001235778a)
RT#3592 provides an instance where the OPENSSL_assert that this commit
replaces can be hit. I was able to recreate this issue by forcing the
underlying BIO to misbehave and come back with very small mtu values. This
happens the second time around the while loop after we have detected that the
MTU has been exceeded following the call to dtls1_write_bytes.
Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit cf75017bfd)
Previously, state variant was not advanced, which resulted in state
being stuck in the st1 variant (usually "_A").
This broke certificate callback retry logic when accepting connections
that were using SSLv2 ClientHello (hence reusing the message), because
their state never advanced to SSL3_ST_SR_CLNT_HELLO_C variant required
for the retry code path.
Reported by Yichun Zhang (agentzh).
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
