Commit Graph

133 Commits

Author SHA1 Message Date
Steven Valdez
e831a81518 Adding support for sending early data on the client.
BUG=76

Change-Id: If58a73da38e46549fd55f84a9104e2dfebfda43f
Reviewed-on: https://boringssl-review.googlesource.com/14164
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-06-15 19:34:59 +00:00
Alessandro Ghedini
de254b4c4e Enforce max_early_data_size on the server.
BUG=76

Change-Id: I8b754ba17b3e0beee425929e4b53785b2e95f0ae
Reviewed-on: https://boringssl-review.googlesource.com/15164
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-04-19 17:21:01 +00:00
David Benjamin
bbba9394c8 Acknowledge KeyUpdate messages.
Also remove TODO about post-handshake authentication. The only sensible
way to handle unexpected post-handshake authentication is a fatal error
(dropping them would cause a deadlock), and we treat all post-handshake
authentication as unexpected.

BUG=74

Change-Id: Ic92035b26ddcbcf25241262ce84bcc57b736b7a7
Reviewed-on: https://boringssl-review.googlesource.com/14744
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-04-10 17:49:58 +00:00
Steven Valdez
a0ba400c33 Add cipher asserts for read/write app data.
Allow the fuzzers to treat this situation, if they ever discover it,
as a bug.

Change-Id: Ie6f1562e9b185d49463cf1a6db28d28780169b11
Reviewed-on: https://boringssl-review.googlesource.com/14424
Reviewed-by: David Benjamin <davidben@google.com>
2017-03-28 21:02:56 +00:00
David Benjamin
bbfe603519 Clean up end_of_early_data processing.
Remove another remnant of the SSL3_PROTOCOL_METHOD hook.

Change-Id: If6bf055e2ee318420e4c5c40b8eb5356eadda68c
Reviewed-on: https://boringssl-review.googlesource.com/14381
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@chromium.org>
Reviewed-by: Steven Valdez <svaldez@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
2017-03-26 20:39:44 +00:00
Steven Valdez
681eb6ac2d Adding support for receiving early data on the server.
BUG=76

Change-Id: Ie894ea5d327f88e66b234767de437dbe5c67c41d
Reviewed-on: https://boringssl-review.googlesource.com/12960
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-03-26 19:30:27 +00:00
Steven Valdez
2d85062c4f Add Data-less Zero-RTT support.
This adds support on the server and client to accept data-less early
data. The server will still fail to parse early data with any
contents, so this should remain disabled.

BUG=76

Change-Id: Id85d192d8e0360b8de4b6971511b5e8a0e8012f7
Reviewed-on: https://boringssl-review.googlesource.com/12921
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-03-25 21:00:18 +00:00
Adam Langley
c68e5b99a7 Establish that the default value of an out-arg for alerts is SSL_AD_DECODE_ERROR.
We already have some cases where the default is DECODE_ERROR and, rather
than have two defaults, just harmonise on that. (INTERNAL_ERROR might
make more sense in some cases, but we don't want to have to remember
what the default is in each case and nobody really cares what the actual
value is anyway.)

Change-Id: I28007898e8d6e7415219145eb9f43ea875028ab2
Reviewed-on: https://boringssl-review.googlesource.com/13720
Reviewed-by: Adam Langley <agl@google.com>
2017-02-09 18:07:30 +00:00
David Benjamin
8671c47bd8 Fold ssl3_write_bytes into ssl3_write_app_data.
It has no other callers, now that the handshake is written elsewhere.

Change-Id: Ib04bbdc4a54fc7d01405d9b3f765fa9f186244de
Reviewed-on: https://boringssl-review.googlesource.com/13540
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-02-02 22:23:46 +00:00
David Benjamin
0efa7592e3 dispatch_alert is not an incidental write.
It is impossible to have to call dispatch_alert when writing application
data. Now that we don't send warning alerts through ssl3_send_alert, all
alerts are closure alerts, which means attempts to write will fail.

This prunes a lot of dead code, avoiding the re-entrancy in the write
path. With that gone, tracking alert_dispatch is much more
straightforward.

BUG=146

Change-Id: Ie5fe677daee71e463d79562f3d2cea822a92581d
Reviewed-on: https://boringssl-review.googlesource.com/13500
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
2017-02-02 17:49:44 +00:00
David Benjamin
f71036e4e3 Remove ssl_hash_message_t from ssl_get_message.
Move to explicit hashing everywhere, matching TLS 1.2 with TLS 1.3. The
ssl_get_message calls between all the handshake states are now all
uniform so, when we're ready, we can rewire the TLS 1.2 state machine to
look like the TLS 1.3 one. (ssl_get_message calls become an
ssl_hs_read_message transition, reuse_message becomes an ssl_hs_ok
transition.)

This avoids some nuisance in processing the ServerHello at the 1.2 / 1.3
transition.

The downside of explicit hashing is we may forget to hash something, but
this will fail to interop with our tests and anyone else, so we should
be able to catch it.

BUG=128

Change-Id: I01393943b14dfaa98eec2a78f62c3a41c29b3a0e
Reviewed-on: https://boringssl-review.googlesource.com/13266
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-01-27 23:23:57 +00:00
David Benjamin
276b7e8127 Move optional message type checks out of ssl_get_message.
This aligns the TLS 1.2 state machine closer with the TLS 1.3 state
machine. This is more work for the handshake, but ultimately the
plan is to take the ssl_get_message call out of the handshake (so it is
just the state machine rather than calling into BIO), so the parameters
need to be folded out as in TLS 1.3.

The WrongMessageType-* family of tests should make sure we don't miss
one of these.

BUG=128

Change-Id: I17a1e6177c52a7540b2bc6b0b3f926ab386c4950
Reviewed-on: https://boringssl-review.googlesource.com/13264
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-01-27 23:15:52 +00:00
David Benjamin
daf207a52a Don't use the buffer BIO in TLS.
On the TLS side, we introduce a running buffer of ciphertext. Queuing up
pending data consists of encrypting the record into the buffer. This
effectively reimplements what the buffer BIO was doing previously, but
this resizes to fit the whole flight.

As part of this, rename all the functions to add to the pending flight
to be more uniform. This CL proposes "add_foo" to add to the pending
flight and "flush_flight" to drain it.

We add an add_alert hook for alerts but, for now, only the SSL 3.0
warning alert (sent mid-handshake) uses this mechanism.  Later work will
push this down to the rest of the write path so closure alerts use it
too, as in DTLS. The intended end state is that all the ssl_buffer.c and
wpend_ret logic will only be used for application data and eventually
optionally replaced by the in-place API, while all "incidental" data
will be handled internally.

For now, the two buffers are mutually exclusive. Moving closure alerts
to "incidentals" will change this, but flushing application data early
is tricky due to wpend_ret. (If we call ssl_write_buffer_flush,
do_ssl3_write doesn't realize it still has a wpend_ret to replay.) That
too is all left alone in this change.

To keep the diff down, write_message is retained for now and will be
removed from the state machines in a follow-up change.

BUG=72

Change-Id: Ibce882f5f7196880648f25d5005322ca4055c71d
Reviewed-on: https://boringssl-review.googlesource.com/13224
Reviewed-by: Adam Langley <agl@google.com>
2017-01-25 23:35:47 +00:00
David Benjamin
17cf2cb1d2 Work around language and compiler bug in memcpy, etc.
Most C standard library functions are undefined if passed NULL, even
when the corresponding length is zero. This gives them (and, in turn,
all functions which call them) surprising behavior on empty arrays.
Some compilers will miscompile code due to this rule. See also
https://www.imperialviolet.org/2016/06/26/nonnull.html

Add OPENSSL_memcpy, etc., wrappers which avoid this problem.

BUG=23

Change-Id: I95f42b23e92945af0e681264fffaf578e7f8465e
Reviewed-on: https://boringssl-review.googlesource.com/12928
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2016-12-21 20:34:47 +00:00
David Benjamin
da86360852 Expose SSL_max_seal_overhead.
Change-Id: I0626f926cad033a19eeb977e454f3c9293f01fd6
Reviewed-on: https://boringssl-review.googlesource.com/12106
Reviewed-by: Adam Langley <agl@google.com>
2016-11-09 16:51:46 +00:00
David Benjamin
c6722cd6e0 Check SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER before touching wpend_buf.
SSL_write has messy semantics around retries. As a sanity-check, it does
pointer and length checks and requires the original and retry SSL_write
pass the same buffer pointer.

In some cases, buffer addresses may change but still include the
original data as a prefix on the retry. Callers then set
SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER to skip the pointer check. But, in
that case, the pointer may have been freed so doing a comparison is
undefined behavior.

Short-circuiting the pointer equality check avoids this problem.

Change-Id: I76cb8f7d45533504cd95287bc53897ca636af51d
Reviewed-on: https://boringssl-review.googlesource.com/11760
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
2016-10-25 20:15:45 +00:00
David Benjamin
c027999c28 Take the version parameter out of ssl_do_msg_callback.
This will make it a little easier to store the normalized version rather
than the wire version. Also document the V2ClientHello behavior.

Change-Id: I5ce9ccce44ca48be2e60ddf293c0fab6bba1356e
Reviewed-on: https://boringssl-review.googlesource.com/11121
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-09-21 18:55:27 +00:00
David Benjamin
33dad1b7a1 Stop pretending to ssl_clear_bad_session.
We broke this to varying degrees ages ago.

This is the logic to implement the variations of rules in TLS to discard
sessions after a failed connection, where a failed connection could be
one of:

- A connection that was not cleanly shut down.

- A connection that received a fatal alert.

The first one is nonsense since close_notify does not actually work in
the real world. The second is a vaguely more plausible but...

- A stateless ticket-based server can't drop sessions anyway.

- In TLS 1.3, a client may receive many tickets over the lifetime of a
  single connection. With an external session cache like ours which may,
  in theory, but multithreaded, this will be a huge hassle to track.

- A client may well attempt to establish a connection and reuse the
  session before we receive the fatal alert, so any application state we
  hope to manage won't really work.

- An attacker can always close the connection before the fatal alert, so
  whatever security policy clearing the session gave is easily
  bypassable.

Implementation-wise, this has basically never worked. The
ssl_clear_bad_session logic called into SSL_CTX_remove_session which
relied on the internal session cache. (Sessions not in the internal
session cache don't get removed.) The internal session cache was only
useful for a server, where tickets prevent this mechanism from doing
anything. For a client, we since removed the internal session cache, so
nothing got removed. The API for a client also did not work as it gave
the SSL_SESSION, not the SSL, so a consumer would not know the key to
invalidate anyway.

The recent session state splitting change further broke this.

Moreover, calling into SSL_CTX_remove_session logic like that is
extremely dubious because it mutates the not_resumable flag on the
SSL_SESSION which isn't thread-safe.

Spec-wise, TLS 1.3 has downgraded the MUST to a SHOULD.

Given all that mess, just remove this code. It is no longer necessary to
call SSL_shutdown just to make session caching work.

Change-Id: Ib601937bfc5f6b40436941e1c86566906bb3165d
Reviewed-on: https://boringssl-review.googlesource.com/9091
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-08-03 21:07:36 +00:00
David Benjamin
163f29af07 Move post-handshake message handling out of read_app_data.
This finishes getting rid of ssl_read_bytes! Now we have separate
entry-points for the various cases. For now, I've kept TLS handshake
consuming records partially. When we do the BIO-less API, I expect that
will need to change, since we won't have the record buffer available.

(Instead, the ssl3_read_handshake_bytes and extend_handshake_buffer pair
will look more like the DTLS side or Go and pull the entire record into
init_buf.)

This change opts to make read_app_data drive the message to completion
in anticipation of DTLS 1.3. That hasn't been specified, but
NewSessionTicket certainly will exist. Knowing that DTLS necessarily has
interleave seems something better suited for the SSL_PROTOCOL_METHOD
internals to drive.

It needs refining, but SSL_PROTOCOL_METHOD is now actually a half-decent
abstraction boundary between the higher-level protocol logic and
DTLS/TLS-specific record-layer and message dispatchy bits.

BUG=83

Change-Id: I9b4626bb8a29d9cb30174d9e6912bb420ed45aff
Reviewed-on: https://boringssl-review.googlesource.com/9001
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-07-29 21:05:49 +00:00
David Benjamin
4792110b2b Forbid interleaving app data in a HelloRequest.
We already forbid renego/app-data interleave. Forbid it within a
HelloRequest too because that's nonsense. No one would ever send:

   [hs:HelloReq-] [app:Hello world] [hs:-uest]

Add tests for this case.

This is in preparation for our more complex TLS 1.3 post-handshake logic
which is going to go through the usual handshake reassembly logic and,
for sanity, will want to enforce this anyway.

BUG=83

Change-Id: I80eb9f3333da3d751f98f25d9469860d1993a97a
Reviewed-on: https://boringssl-review.googlesource.com/9000
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-07-29 15:44:42 +00:00
Steven Valdez
143e8b3fd9 Add TLS 1.3 1-RTT.
This adds the machinery for doing TLS 1.3 1RTT.

Change-Id: I736921ffe9dc6f6e64a08a836df6bb166d20f504
Reviewed-on: https://boringssl-review.googlesource.com/8720
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-07-18 09:54:46 +00:00
David Benjamin
397c8e6fb6 Forbid renegotiation in TLS 1.3.
Change-Id: I1b34acbbb5528e7e31595ee0cbce7618890f3955
Reviewed-on: https://boringssl-review.googlesource.com/8669
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-11 18:26:27 +00:00
David Benjamin
f0ee907942 Remove the 'ssl_' prefix on most SSL_PROTOCOL_METHOD hooks.
It doesn't really convey anything useful. Leave ssl_get_message alone for now
since it's called everywhere in the handshake and I'm about to tweak it
further.

Change-Id: I6f3a74c170e818f624be8fbe5cf6b796353406df
Reviewed-on: https://boringssl-review.googlesource.com/8430
Reviewed-by: Adam Langley <agl@google.com>
2016-06-27 18:43:33 +00:00
David Benjamin
585320c9e9 Don't call read_bytes in read_change_cipher_spec.
Change-Id: If7d50e43c8ea28c5eed38209f31d481fb57bf225
Reviewed-on: https://boringssl-review.googlesource.com/8175
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 18:51:54 +00:00
David Benjamin
4aa4081e7f Don't use ssl3_read_bytes in ssl3_read_close_notify.
read_close_notify is a very straight-forward hook and doesn't need much.

Change-Id: I7407d842321ea1bcb47838424a0d8f7550ad71ca
Reviewed-on: https://boringssl-review.googlesource.com/8174
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 18:39:26 +00:00
David Benjamin
a7810c12e9 Make tls_open_record always in-place.
The business with ssl_record_prefix_len is rather a hassle. Instead, have
tls_open_record always decrypt in-place and give back a CBS to where the body
is.

This way the caller doesn't need to do an extra check all to avoid creating an
invalid pointer and underflow in subtraction.

Change-Id: I4e12b25a760870d8f8a503673ab00a2d774fc9ee
Reviewed-on: https://boringssl-review.googlesource.com/8173
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 18:39:07 +00:00
David Benjamin
728f354a2b Push alert handling down into the record functions.
Alert handling is more-or-less identical across all contexts. Push it down from
read_bytes into the low-level record functions. This also deduplicates the code
shared between TLS and DTLS.

Now the only type mismatch managed by read_bytes is if we get handshake data in
read_app_data.

Change-Id: Ia8331897b304566e66d901899cfbf31d2870194e
Reviewed-on: https://boringssl-review.googlesource.com/8124
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 18:35:58 +00:00
David Benjamin
4e9cc71a27 Add helper functions for info_callback and msg_callback.
This is getting a little repetitive.

Change-Id: Ib0fa8ab10149557c2d728b88648381b9368221d9
Reviewed-on: https://boringssl-review.googlesource.com/8126
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 18:13:53 +00:00
David Benjamin
4bea8509da Lift an impossible check to an assert.
This cannot happen.

Change-Id: Ib1b473aa91d6479eeff43f7eaf94906d0b2c2a8f
Reviewed-on: https://boringssl-review.googlesource.com/8123
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-06 20:47:07 +00:00
Adam Langley
1cb405d96b Revert "Forbid calling SSL_read, SSL_peek, and SSL_do_handshake post-shutdown."
This reverts commit c7eae5a326. pyOpenSSL
expects to be able to call |SSL_read| after a shutdown and get EOF.

Change-Id: Icc5faa09d644ec29aac99b181dac0db197f283e3
Reviewed-on: https://boringssl-review.googlesource.com/8060
Reviewed-by: Adam Langley <agl@google.com>
2016-05-25 23:23:12 +00:00
David Benjamin
54092ffeaa Remove dead checks.
Those checks contradict an assert up in read_app_data. This is part of
shrinking read_bytes further into get_record and its callers until it goes
away. Here, this kind of policy should be controlled by the callers.

Change-Id: If8f9a45b8b95093beab1b3d4abcd31da55c65322
Reviewed-on: https://boringssl-review.googlesource.com/7954
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 20:52:38 +00:00
David Benjamin
c7eae5a326 Forbid calling SSL_read, SSL_peek, and SSL_do_handshake post-shutdown.
This explicitly forbids an API pattern which formerly kind of worked, but was
extremely buggy (see preceding commits). Depending on how one interprets
close_notify and our API, one might wish to call SSL_shutdown only once
(morally shutdown(SHUT_WR)) and then SSL_read until EOF.

However, this exposes additional confusing states where we might try to send an
alert post-SHUT_WR, etc. Early commits made us more robust here (whether one is
allowed to touch the SSL* after an operattion failed because it read an alert
is... unclear), so we could support it if we wanted to, but this doesn't seem
worth the additional statespace. See if we can get away with not allowing it.

Change-Id: Ie7a7e5520b464360b1e6316c34ec9854b571782f
Reviewed-on: https://boringssl-review.googlesource.com/7433
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-17 21:28:40 +00:00
David Benjamin
ea65e100c7 Condition the read_close_notify check on type, not shutdown state.
The logic to drop records really should be in the caller. Unless
ssl3_read_bytes is broken apart, condition on the type field which is more
robust.

If we manage to call, say, SSL_read after SSL_shutdown completes at 0 (instead
of 1), this logic can incorrectly cause unknown record types to be dropped.

Change-Id: Iab90e5d9190fcccbf6ff55e17079a2704ed99901
Reviewed-on: https://boringssl-review.googlesource.com/7953
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-17 21:27:43 +00:00
David Benjamin
fa214e4a18 Tidy up shutdown state.
The existing logic gets confused in a number of cases around close_notify vs.
fatal alert. SSL_shutdown, while still pushing to the error queue, will fail to
notice alerts. We also get confused if we try to send a fatal alert when we've
already sent something else.

Change-Id: I9b1d217fbf1ee8a9c59efbebba60165b7de9689e
Reviewed-on: https://boringssl-review.googlesource.com/7952
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-17 21:27:12 +00:00
David Benjamin
8f73135485 Consolidate SSL_RECEIVED_SHUTDOWN checks.
SSL_RECEIVED_SHUTDOWN checks in the record layer happen in two different
places. Some operations (but not all) check it, and so does read_bytes. Move it
to get_record.

This check should be at a low-level since it is otherwise duplicated in every
operation. It is also a signal which originates from around the peer's record
layer, so it makes sense to check it near the same code. (This one's in
get_record which is technically lower-level than read_bytes, but we're trying
to get rid of read_bytes. They're very coupled functions.)

Also, if we've seen a fatal alert, replay an error, not an EOF.

Change-Id: Idec35c5068ddabe5b1a9145016d8f945da2421cf
Reviewed-on: https://boringssl-review.googlesource.com/7436
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-17 21:02:19 +00:00
David Benjamin
4c5ddb8047 Set rwstate consistently.
We reset it to SSL_NOTHING at the start of ever SSL_get_error-using operation.
Then we only set it to a non-NOTHING value in the rest of the stack on error
paths.

Currently, ssl->rwstate is set all over the place. Sometimes the pattern is:

  ssl->rwstate = SSL_WRITING;
  if (BIO_write(...) <= 0) {
    goto err;
  }
  ssl->rwstate = SSL_NOTHING;

Sometimes we only set it to the non-NOTHING value on error.

  if (BIO_write(...) <= 0) {
    ssl->rwstate = SSL_WRITING;
  }
  ssl->rwstate = SSL_NOTHING;

Sometimes we just set it to SSL_NOTHING far from any callback in random places.

The third case is arbitrary and clearly should be removed.

But, in the second case, we sometimes forget to undo it afterwards. This is
largely harmless since an error in the error queue overrides rwstate, but we
don't always put something in the error queue (falling back to
SSL_ERROR_SYSCALL for "I'm not sure why it failed. Perhaps it was one of your
callbacks? Check your errno equivalent."), but in that case a stray rwstate
value will cause it to be wrong.

We could fix the cases where we fail to set SSL_NOTHING on success cases, but
this doesn't account for there being multiple SSL_get_error operations. The
consumer may have an SSL_read and an SSL_write running concurrently. Instead,
it seems the best option is to lift the SSL_NOTHING reset to the operations and
set SSL_WRITING and friends as in the second case.

(Someday hopefully we can fix this to just be an enum that is internally
returned. It can convert to something stateful at the API layer.)

Change-Id: I54665ec066a64eb0e48a06e2fcd0d2681a42df7f
Reviewed-on: https://boringssl-review.googlesource.com/7453
Reviewed-by: David Benjamin <davidben@google.com>
2016-04-18 20:30:32 +00:00
David Benjamin
c6972eb1f0 Remove the no_renegotiation special case.
The concern is if the peer denies our renegotiation attempt, but we will never
initiate renegotiation. We only support server-initiated renegotiation when we
are acting as the client.

(Strictly speaking, only the client ever initiates renegotiation. The server
sends a HelloRequest to ask the client to initiate it. But we forbid
application data interleave as soon as we see the HelloRequest, so we treat it
as part of the handshake.)

Change-Id: I1a625130de32a7227e4471f2f889255aba962ce4
Reviewed-on: https://boringssl-review.googlesource.com/7452
Reviewed-by: Emily Stark (Dunn) <estark@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-04-18 20:29:30 +00:00
David Benjamin
0d3a8c6ac0 Don't allow alert records with multiple alerts.
This is just kind of a silly thing to do. NSS doesn't allow them either. Fatal
alerts would kill the connection regardless and warning alerts are useless. We
previously stopped accepting fragmented alerts but still allowed them doubled
up.

This is in preparation for pulling the shared alert processing code between TLS
and DTLS out of read_bytes into some common place.

Change-Id: Idbef04e39ad135f9601f5686d41f54531981e0cf
Reviewed-on: https://boringssl-review.googlesource.com/7451
Reviewed-by: Emily Stark (Dunn) <estark@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-04-18 20:29:02 +00:00
David Benjamin
c79845c2a8 Move implicit handshake driving out of read_bytes.
This removes the final use of in_handshake. Note that there is still a
rentrant call of read_bytes -> handshake_func when we see a
HelloRequest. That will need to be signaled up to ssl_read_impl
separately out of read_app_data.

Change-Id: I823de243f75e6b73eb40c6cf44157b4fc21eb8fb
Reviewed-on: https://boringssl-review.googlesource.com/7439
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-26 20:23:25 +00:00
David Benjamin
d7ac143814 Lift the handshake driving in write_bytes up to SSL_write.
This removes one use of in_handshake and consolidates some DTLS and TLS
code.

Change-Id: Ibbdd38360a983dabfb7b18c7bd59cb5e316b2adb
Reviewed-on: https://boringssl-review.googlesource.com/7435
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-26 20:09:37 +00:00
David Benjamin
282511d7eb Consolidate shutdown state.
fatal_alert isn't read at all right now, and warn_alert is only checked
for close_notify. We only need three states:

 - Not shutdown.
 - Got a fatal alert (don't care which).
 - Got a warning close_notify.

Leave ssl->shutdown alone for now as it's tied up with SSL_set_shutdown
and friends. To distinguish the remaining two, we only need a boolean.

Change-Id: I5877723af82b76965c75cefd67ec1f981242281b
Reviewed-on: https://boringssl-review.googlesource.com/7434
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-26 20:04:34 +00:00
David Benjamin
51545ceac6 Remove a number of unnecessary stdio.h includes.
Change-Id: I6267c9bfb66940d0b6fe5368514210a058ebd3cc
Reviewed-on: https://boringssl-review.googlesource.com/7494
Reviewed-by: Emily Stark (Dunn) <estark@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-17 18:22:28 +00:00
David Benjamin
a857159dd6 Clean up some silly variable names.
Change-Id: I5b38e2938811520f52ece6055245248c80308b4d
Reviewed-on: https://boringssl-review.googlesource.com/7416
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-10 19:21:20 +00:00
David Benjamin
a565d29ce6 Remove alert mapping machinery.
For TLS, this machinery only exists to swallow no_certificate alerts
which only get sent in an SSL 3.0 codepath anyway. It's much less a
no-op for SSL 3.0 which, strictly speaking, has only a subset of TLS's
alerts.

This gets messy around version negotiation because of the complex
relationship between enc_method, have_version, and version which all get
set at different times. Given that SSL 3.0 is nearly dead and all these
alerts are fatal to the connection anyway, this doesn't seem worth
carrying around. (It doesn't work very well anyway. An SSLv3-only server
may still send a record_overflow alert before version negotiation.)

This removes the last place enc_method is accessed prior to version
negotiation.

Change-Id: I79a704259fca69e4df76bd5a6846c9373f46f5a9
Reviewed-on: https://boringssl-review.googlesource.com/6843
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-27 21:28:48 +00:00
David Benjamin
79978df4ec Move aead_{read,write}_ctx and next_proto_negotiated into ssl->s3.
Both are connection state rather than configuration state. Notably this
cuts down more of SSL_clear that can't just use ssl_free + ssl_new.

Change-Id: I3c05b3ae86d4db8bd75f1cd21656f57fc5b55ca9
Reviewed-on: https://boringssl-review.googlesource.com/6835
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-15 21:40:25 +00:00
David Benjamin
57997da8ee Simplify the ChangeCipherSpec logic.
It's the same between TLS and SSL 3.0. There's also no need for the
do_change_cipher_spec wrapper (it no longer needs checks to ensure it
isn't called at a bad place). Finally fold the setup_key_block call into
change_cipher_spec.

Change-Id: I7917f48e1a322f5fbafcf1dfb8ad53f66565c314
Reviewed-on: https://boringssl-review.googlesource.com/6834
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-15 21:33:57 +00:00
David Benjamin
0623bceb25 Fill in ssl->session->cipher when resumption is resolved.
Doing it at ChangeCipherSpec makes it be set twice and, more
importantly, causes us to touch SSL_SESSION objects on resumption. (With
a no-op change, but this still isn't a good idea.)

This should actually let us get rid of ssl->s3->tmp.new_cipher but some
of external code accesses that field directly.

Change-Id: Ia6b7e0964c1b430f963ad0b1a5417b339b7b19d3
Reviewed-on: https://boringssl-review.googlesource.com/6833
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-15 20:46:45 +00:00
David Benjamin
0d56f888c3 Switch s to ssl everywhere.
That we're half and half is really confusing.

Change-Id: I1c2632682e8a3e63d01dada8e0eb3b735ff709ce
Reviewed-on: https://boringssl-review.googlesource.com/6785
Reviewed-by: Adam Langley <agl@google.com>
2015-12-22 23:28:22 +00:00
David Benjamin
7fc010014c Slightly simplify SSL3_RECORD.
There's no need to track consumed bytes, so rr->data and rr->off may be
merged together.

Change-Id: I8842d005665ea8b4d4a0cced941f3373872cdac4
Reviewed-on: https://boringssl-review.googlesource.com/6644
Reviewed-by: Adam Langley <agl@google.com>
2015-12-16 18:41:59 +00:00
David Benjamin
a41280d8cb Pull ChangeCipherSpec into the handshake state machine.
This uses ssl3_read_bytes for now. We still need to dismantle that
function and then invert the handshake state machine, but this gets
things closer to the right shape as an intermediate step and is a large
chunk in itself. It simplifies a lot of the CCS/handshake
synchronization as a lot of the invariants much more clearly follow from
the handshake itself.

Tests need to be adjusted since this changes some error codes. Now all
the CCS/Handshake checks fall through to the usual
SSL_R_UNEXPECTED_RECORD codepath. Most of what used to be a special-case
falls out naturally. (If half of Finished was in the same record as the
pre-CCS message, that part of the handshake record would have been left
unconsumed, so read_change_cipher_spec would have noticed, just like
read_app_data would have noticed.)

Change-Id: I15c7501afe523d5062f0e24a3b65f053008d87be
Reviewed-on: https://boringssl-review.googlesource.com/6642
Reviewed-by: Adam Langley <agl@google.com>
2015-12-16 18:36:57 +00:00