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>
once the ChangeCipherSpec message is received. Previously, the server would
set the flag once at SSL3_ST_SR_CERT_VRFY and again at SSL3_ST_SR_FINISHED.
This would allow a second CCS to arrive and would corrupt the server state.
(Because the first CCS would latch the correct keys and subsequent CCS
messages would have to be encrypted, a MitM attacker cannot exploit this,
though.)
Thanks to Joeri de Ruiter for reporting this issue.
Reviewed-by: Matt Caswell <matt@openssl.org>
The server must send a NewSessionTicket message if it advertised one
in the ServerHello, so make a missing ticket message an alert
in the client.
An equivalent change was independently made in BoringSSL, see commit
6444287806d801b9a45baf1f6f02a0e3a16e144c.
Reviewed-by: Matt Caswell <matt@openssl.org>
The client sends a session ID with the session ticket, and uses
the returned ID to detect resumption, so we do not need to peek
at handshake messages: s->hit tells us explicitly if we're resuming.
An equivalent change was independently made in BoringSSL, see commit
407886f589cf2dbaed82db0a44173036c3bc3317.
Reviewed-by: Matt Caswell <matt@openssl.org>
This ensures that it's zeroed even if the SSL object is reused
(as in ssltest.c). It also ensures that it applies to DTLS, too.
Reviewed-by: Matt Caswell <matt@openssl.org>
When no-ssl3 is set only make SSLv3 disabled by default. Retain -ssl3
options for s_client/s_server/ssltest.
When no-ssl3-method is set SSLv3_*method() is removed and all -ssl3
options.
We should document this somewhere, e.g. wiki, FAQ or manual page.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Tighten client-side session ticket handling during renegotiation:
ensure that the client only accepts a session ticket if the server sends
the extension anew in the ServerHello. Previously, a TLS client would
reuse the old extension state and thus accept a session ticket if one was
announced in the initial ServerHello.
Reviewed-by: Bodo Moeller <bodo@openssl.org>
that fixed PR#3450 where an existing cast masked an issue when i was changed
from int to long in that commit
Picked up on z/linux (s390) where sizeof(int)!=sizeof(long)
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Fix a bug in handling of 128 byte long PSK identity in
psk_client_callback.
OpenSSL supports PSK identities of up to (and including) 128 bytes in
length. PSK identity is obtained via the psk_client_callback,
implementors of which are expected to provide a NULL-terminated
identity. However, the callback is invoked with only 128 bytes of
storage thus making it impossible to return a 128 byte long identity and
the required additional NULL byte.
This CL fixes the issue by passing in a 129 byte long buffer into the
psk_client_callback. As a safety precaution, this CL also zeroes out the
buffer before passing it into the callback, uses strnlen for obtaining
the length of the identity returned by the callback, and aborts the
handshake if the identity (without the NULL terminator) is longer than
128 bytes.
(Original patch amended to achieve strnlen in a different way.)
Reviewed-by: Rich Salz <rsalz@openssl.org>
The addition of SRP authentication needs to be checked in various places
to work properly. Specifically:
A certificate is not sent.
A certificate request must not be sent.
Server key exchange message must not contain a signature.
If appropriate SRP authentication ciphersuites should be chosen.
Reviewed-by: Matt Caswell <matt@openssl.org>
Allow CCS after finished has been sent by client: at this point
keys have been correctly set up so it is OK to accept CCS from
server. Without this renegotiation can sometimes fail.
PR#3400
Only accept change cipher spec when it is expected instead of at any
time. This prevents premature setting of session keys before the master
secret is determined which an attacker could use as a MITM attack.
Thanks to KIKUCHI Masashi (Lepidum Co. Ltd.) for reporting this issue
and providing the initial fix this patch is based on.
(cherry picked from commit bc8923b1ec)
Security callback: selects which parameters are permitted including
sensible defaults based on bits of security.
The "parameters" which can be selected include: ciphersuites,
curves, key sizes, certificate signature algorithms, supported
signature algorithms, DH parameters, SSL/TLS version, session tickets
and compression.
In some cases prohibiting the use of a parameters will mean they are
not advertised to the peer: for example cipher suites and ECC curves.
In other cases it will abort the handshake: e.g DH parameters or the
peer key size.
Documentation to follow...
New function ssl_cipher_disabled.
Check for disabled client ciphers using ssl_cipher_disabled.
New function to return only supported ciphers.
New option to ciphers utility to print only supported ciphers.
If multiple TLS extensions are expected but not received, the TLS extension and supplemental data 'generate' callbacks are the only chance for the receive-side to trigger a specific TLS alert during the handshake.
Removed logic which no-op'd TLS extension generate callbacks (as the generate callbacks need to always be called in order to trigger alerts), and updated the serverinfo-specific custom TLS extension callbacks to track which custom TLS extensions were received by the client, where no-ops for 'generate' callbacks are appropriate.
DHE is the standard term used by the RFCs and by other TLS
implementations. It's useful to have the internal variables use the
standard terminology.
This patch leaves a synonym SSL_kEDH in place, though, so that older
code can still be built against it, since that has been the
traditional API. SSL_kEDH should probably be deprecated at some
point, though.
ECDHE is the standard term used by the RFCs and by other TLS
implementations. It's useful to have the internal variables use the
standard terminology.
This patch leaves a synonym SSL_kEECDH in place, though, so that older
code can still be built against it, since that has been the
traditional API. SSL_kEECDH should probably be deprecated at some
point, though.
Instead, send random bytes, unless SSL_SEND_{CLIENT,SERVER}RANDOM_MODE
is set.
This is a forward-port of commits:
4af793036ff4c93b46ed3da721dac92583270191
While the gmt_unix_time record was added in an ostensible attempt to
mitigate the dangers of a bad RNG, its presence leaks the host's view
of the current time in the clear. This minor leak can help
fingerprint TLS instances across networks and protocols... and what's
worse, it's doubtful thet the gmt_unix_time record does any good at
all for its intended purpose, since:
* It's quite possible to open two TLS connections in one second.
* If the PRNG output is prone to repeat itself, ephemeral
handshakes (and who knows what else besides) are broken.
Make DTLS behave like TLS when negotiating version: record layer has
DTLS 1.0, message version is 1.2.
Tolerate different version numbers if version hasn't been negotiated
yet.
Removed prior audit proof logic - audit proof support was implemented using the generic TLS extension API
Tests exercising the new supplemental data registration and callback api can be found in ssltest.c.
Implemented changes to s_server and s_client to exercise supplemental data callbacks via the -auth argument, as well as additional flags to exercise supplemental data being sent only during renegotiation.
Check for Suite B support using method flags instead of version numbers:
anything supporting TLS 1.2 cipher suites will also support Suite B.
Return an error if an attempt to use DTLS 1.0 is made in Suite B mode.
Add new methods DTLS_*_method() which support both DTLS 1.0 and DTLS 1.2 and
pick the highest version the peer supports during negotiation.
As with SSL/TLS options can change this behaviour specifically
SSL_OP_NO_DTLSv1 and SSL_OP_NO_DTLSv1_2.
Add correct flags for DTLS 1.2, update s_server and s_client to handle
DTLS 1.2 methods.
Currently no support for version negotiation: i.e. if client/server selects
DTLS 1.2 it is that or nothing.
Use the enc_flags field to determine whether we should use explicit IV,
signature algorithms or SHA256 default PRF instead of hard coding which
versions support each requirement.
Revise DTLS code. There was a *lot* of code duplication in the
DTLS code that generates records. This makes it harder to maintain and
sometimes a TLS update is omitted by accident from the DTLS code.
Specifically almost all of the record generation functions have code like
this:
some_pointer = buffer + HANDSHAKE_HEADER_LENGTH;
... Record creation stuff ...
set_handshake_header(ssl, SSL_MT_SOMETHING, message_len);
...
write_handshake_message(ssl);
Where the "Record creation stuff" is identical between SSL/TLS and DTLS or
in some cases has very minor differences.
By adding a few fields to SSL3_ENC to include the header length, some flags
and function pointers for handshake header setting and handshake writing the
code can cope with both cases.
Note: although this passes "make test" and some simple DTLS tests there may
be some minor differences in the DTLS code that have to be accounted for.
by a certificate chain. Add additional tests to handle client
certificates: checks for matching certificate type and issuer name
comparison.
Print out results of checks for each candidate chain tested in
s_server/s_client.
