Commit Graph

242 Commits

Author SHA1 Message Date
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
981936791e Remove some easy obj.h dependencies.
A lot of consumers of obj.h only want the NID values. Others didn't need
it at all. This also removes some OBJ_nid2sn and OBJ_nid2ln calls in EVP
error paths which isn't worth pulling a large table in for.

BUG=chromium:499653

Change-Id: Id6dff578f993012e35b740a13b8e4f9c2edc0744
Reviewed-on: https://boringssl-review.googlesource.com/7563
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-31 20:50:33 +00:00
David Benjamin
e29ea166a6 Use ssl3_is_version_enabled to skip offering sessions.
We do an ad-hoc upper-bound check, but if the version is too low, we also
shouldn't offer the session. This isn't fatal to the connection and doesn't
have issues (we'll check the version later regardless), but offering a session
we're never going to accept is pointless. The check should match what we do in
ServerHello.

Credit to Matt Caswell for noticing the equivalent issue in an OpenSSL pull
request.

Change-Id: I17a4efd37afa63b34fca53f4c9b7ac3ae2fa3336
Reviewed-on: https://boringssl-review.googlesource.com/7543
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-28 16:01:37 +00:00
David Benjamin
baca950e8e Remove in_handshake.
The removes the last of OpenSSL's variables that count occurrences of a
function on the stack.

Change-Id: I1722c6d47bedb47b1613c4a5da01375b5c4cc220
Reviewed-on: https://boringssl-review.googlesource.com/7450
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-26 20:24:28 +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
a5177cb319 Use a less tedious pattern for X509_NAME.
Also fix a long/unsigned-long cast. (ssl_get_message returns long. It really
shouldn't, but ssl_get_message needs much more work than just a long -> size_t
change, so leave it as long for now.)

Change-Id: Ice8741f62a138c0f35ca735eedb541440f57e114
Reviewed-on: https://boringssl-review.googlesource.com/7457
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-14 23:12:35 +00:00
David Benjamin
6b6e0b2089 Fix a memory leak in ssl3_get_certificate_request.
Found by libFuzzer.

Change-Id: Ifa343a184cc65f71fb6591d290b2d47d24a2be80
Reviewed-on: https://boringssl-review.googlesource.com/7456
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-14 23:12:22 +00:00
David Benjamin
15c1488b61 Clear the error queue on entry to core SSL operations.
OpenSSL historically made some poor API decisions. Rather than returning a
status enum in SSL_read, etc., these functions must be paired with
SSL_get_error which determines the cause of the last error's failure. This
requires SSL_read communicate with SSL_get_error with some stateful flag,
rwstate.

Further, probably as workarounds for bugs elsewhere, SSL_get_error does not
trust rwstate. Among other quirks, if the error queue is non-empty,
SSL_get_error overrides rwstate and returns a value based on that. This
requires that SSL_read, etc., be called with an empty error queue. (Or we hit
one of the spurious ERR_clear_error calls in the handshake state machine,
likely added as further self-workarounds.)

Since requiring callers consistently clear the error queue everywhere is
unreasonable (crbug.com/567501), clear ERR_clear_error *once* at the entry
point. Until/unless[*] we make SSL_get_error sane, this is the most reasonable
way to get to the point that clearing the error queue on error is optional.

With those in place, the calls in the handshake state machine are no longer
needed. (I suspect all the ERR_clear_system_error calls can also go, but I'll
investigate and think about that separately.)

[*] I'm not even sure it's possible anymore, thanks to the possibility of
BIO_write pushing to the error queue.

BUG=567501,593963

Change-Id: I564ace199e5a4a74b2554ad3335e99cd17120741
Reviewed-on: https://boringssl-review.googlesource.com/7455
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-14 19:05:05 +00:00
David Benjamin
df28c3acf1 Tidy up the client Certificate message skipping slightly.
Align all unexpected messages on SSL_R_UNEXPECTED_MESSAGE. Make the SSL 3.0
case the exceptional case. In doing so, make sure the SSL 3.0
SSL_VERIFY_FAIL_IF_NO_PEER_CERT case has its own test as that's a different
handshake shape.

Change-Id: I1a539165093fbdf33e2c1b25142f058aa1a71d83
Reviewed-on: https://boringssl-review.googlesource.com/7421
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-11 19:10:55 +00:00
David Benjamin
454aa4c25e Rewrite ssl3_send_client_certificate.
The old logic was quite messy and grew a number of no-ops over the
years. It was also unreasonably fond of the variable name |i|.

The current logic wasn't even correct. It's overly fond of sending no
certificate, even when it pushes errors on the error queue for a fatal
error.

Change-Id: Ie5b2b38dd309f535af1d17fa261da7dc23185866
Reviewed-on: https://boringssl-review.googlesource.com/7418
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-11 19:10:19 +00:00
David Benjamin
bf82aede67 Disable all TLS crypto in fuzzer mode.
Both sides' signature and Finished checks still occur, but the results
are ignored. Also, all ciphers behave like the NULL cipher.
Conveniently, this isn't that much code since all ciphers and their size
computations funnel into SSL_AEAD_CTX.

This does carry some risk that we'll mess up this code. Up until now, we've
tried to avoid test-only changes to the SSL stack.

There is little risk that anyone will ship a BORINGSSL_UNSAFE_FUZZER_MODE build
for anything since it doesn't interop anyway. There is some risk that we'll end
up messing up the disableable checks. However, both skipped checks have
negative tests in runner (see tests that set InvalidSKXSignature and
BadFinished). For good measure, I've added a server variant of the existing
BadFinished test to this CL, although they hit the same code.

Change-Id: I37f6b4d62b43bc08fab7411965589b423d86f4b8
Reviewed-on: https://boringssl-review.googlesource.com/7287
Reviewed-by: Adam Langley <agl@google.com>
2016-03-02 23:39:36 +00:00
David Benjamin
2b07fa4b22 Fix a memory leak in an error path.
Found by libFuzzer combined with some experimental unsafe-fuzzer-mode patches
(to be uploaded once I've cleaned them up a bit) to disable all those pesky
cryptographic checks in the protocol.

Change-Id: I9153164fa56a0c2262c4740a3236c2b49a596b1b
Reviewed-on: https://boringssl-review.googlesource.com/7282
Reviewed-by: Adam Langley <agl@google.com>
2016-03-02 15:49:30 +00:00
David Benjamin
b83003ebc6 Don't initialize enc_method before version negotiation.
Move it into ssl->s3 so it automatically behaves correctly on SSL_clear.
ssl->version is still a mess though.

Change-Id: I17a692a04a845886ec4f8de229fa6cf99fa7e24a
Reviewed-on: https://boringssl-review.googlesource.com/6844
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-27 21:38:12 +00:00
David Benjamin
a1e9cabd8b Replace enc_flags with normalized version checks.
This removes the various non-PRF checks from SSL3_ENC_METHOD so that can
have a clearer purpose. It also makes TLS 1.0 through 1.2's
SSL3_ENC_METHOD tables identical and gives us an assert to ensure
nothing accesses the version bits before version negotiation.
Accordingly, ssl_needs_record_splitting was reordered slightly so we
don't rely on enc_method being initialized to TLS 1.2
pre-version-negotiation.

This leaves alert_value as the only part of SSL3_ENC_METHOD which may be
accessed before version negotiation.

Change-Id: If9e299e2ef5511b5fa442b2af654eed054c3e675
Reviewed-on: https://boringssl-review.googlesource.com/6842
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-27 21:17:55 +00:00
David Benjamin
b9e4fa5e02 Add a helper function to normalize the current version.
We have need to normalize other versions during version negotiation, but
almost all will be post-negotiation. Hopefully later this can be
replaced with a value explicitly stored on the object and we do away
with ssl->version.

Change-Id: I595db9163d0af2e7c083b9a09310179aaa9ac812
Reviewed-on: https://boringssl-review.googlesource.com/6841
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-15 22:17:00 +00:00
David Benjamin
baa1216ac0 Prune finished labels from SSL3_ENC_METHOD.
There's not much point in putting those in the interface as the
final_finished_mac implementation is itself different between SSL 3.0
and TLS.

Change-Id: I76528a88d255c451ae008f1a34e51c3cb57d3073
Reviewed-on: https://boringssl-review.googlesource.com/6838
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-15 22:04:53 +00:00
David Benjamin
f8d807176a Remove a few unnecessary SSL3_ENC_METHOD hooks.
As things stand now, they don't actually do anything.

Change-Id: I9f8b4cbf38a0dffabfc5265805c52bb8d7a8fb0d
Reviewed-on: https://boringssl-review.googlesource.com/6837
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-15 22:02:30 +00:00
David Benjamin
b35d68483c Minor cleanup.
Mostly alg_k and alg_a variables had the wrong type.

Change-Id: I66ad4046b1f5a4e3e58bc407096d95870b42b9dd
Reviewed-on: https://boringssl-review.googlesource.com/6836
Reviewed-by: Adam Langley <alangley@gmail.com>
2016-01-15 22:01:28 +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
974c7ba4ef Route DHE through the SSL_ECDH abstraction as well.
This unifies the ClientKeyExchange code rather nicely. ServerKeyExchange
is still pretty specialized. For simplicity, I've extended the yaSSL bug
workaround for clients as well as servers rather than route in a
boolean.

Chrome's already banished DHE to a fallback with intention to remove
altogether later, and the spec doesn't say anything useful about
ClientDiffieHellmanPublic encoding, so this is unlikely to cause
problems.

Change-Id: I0355cd1fd0fab5729e8812e4427dd689124f53a2
Reviewed-on: https://boringssl-review.googlesource.com/6784
Reviewed-by: Adam Langley <agl@google.com>
2015-12-22 23:17:32 +00:00
David Benjamin
4298d77379 Implement draft-ietf-tls-curve25519-01 in C.
The new curve is not enabled by default.

As EC_GROUP/EC_POINT is a bit too complex for X25519, this introduces an
SSL_ECDH_METHOD abstraction which wraps just the raw ECDH operation. It
also tidies up some of the curve code which kept converting back and
force between NIDs and curve IDs. Now everything transits as curve IDs
except for API entry points (SSL_set1_curves) which take NIDs. Those
convert immediately and act on curve IDs from then on.

Note that, like the Go implementation, this slightly tweaks the order of
operations. The client sees the server public key before sending its
own. To keep the abstraction simple, SSL_ECDH_METHOD expects to
generate a keypair before consuming the peer's public key. Instead, the
client handshake stashes the serialized peer public value and defers
parsing it until it comes time to send ClientKeyExchange. (This is
analogous to what it was doing before where it stashed the parsed peer
public value instead.)

It still uses TLS 1.2 terminology everywhere, but this abstraction should also
be compatible with TLS 1.3 which unifies (EC)DH-style key exchanges.
(Accordingly, this abstraction intentionally does not handle parsing the
ClientKeyExchange/ServerKeyExchange framing or attempt to handle asynchronous
plain RSA or the authentication bits.)

BUG=571231

Change-Id: Iba09dddee5bcdfeb2b70185308e8ab0632717932
Reviewed-on: https://boringssl-review.googlesource.com/6780
Reviewed-by: Adam Langley <agl@google.com>
2015-12-22 21:51:30 +00:00
David Benjamin
fc8251258d Convert ssl3_send_cert_verify to CBB.
In doing so, make the asynchronous portion look more like
ssl3_send_server_key_exchange. This is a considerably simpler structure,
so the save/resume doesn't need any state.

Mostly this means writing out the signature algorithm can now go through
CBB rather than a uint8_t* without bounds check.

Change-Id: If99fcffd0d41a84514c3d23034062c582f1bccb2
Reviewed-on: https://boringssl-review.googlesource.com/6771
Reviewed-by: Adam Langley <agl@google.com>
2015-12-22 17:40:47 +00:00
David Benjamin
ae0eaaa397 Convert ssl3_send_client_key_exchange to CBB.
This relieves some complexity budget for adding Curve25519 to this
code.

This also adds a BN_bn2cbb_padded helper function since this seems to be a
fairly common need.

Change-Id: Ied0066fdaec9d02659abd6eb1a13f33502c9e198
Reviewed-on: https://boringssl-review.googlesource.com/6767
Reviewed-by: Adam Langley <agl@google.com>
2015-12-22 17:00:56 +00:00
David Benjamin
48cce66aac Tidy up ssl3_get_server_key_exchange slightly.
Single-use BN_CTXs are unnecessary.

Change-Id: I2d59aae2168e43937c5d527794c335ed2809d547
Reviewed-on: https://boringssl-review.googlesource.com/6766
Reviewed-by: Adam Langley <agl@google.com>
2015-12-22 00:25:45 +00:00
David Benjamin
c1cc858af2 Check for EC_KEY_set_public_key error.
This function may fail on malloc error.

Change-Id: I8631b1763dac5a3801fcaca81bdfcb8d24d3728c
Reviewed-on: https://boringssl-review.googlesource.com/6765
Reviewed-by: Adam Langley <agl@google.com>
2015-12-22 00:24:24 +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
David Benjamin
758d12732a Add get0 getters for EVP_PKEY.
Right now your options are:
- Bounce on a reference and deal with cleanup needlessly.
- Manually check the type tag and peek into the union.

We probably have no hope of opaquifying this struct, but for new code, let's
recommend using this function rather than the more error-prone thing.

Change-Id: I9b39ff95fe4264a3f7d1e0d2894db337aa968f6c
Reviewed-on: https://boringssl-review.googlesource.com/6551
Reviewed-by: Adam Langley <agl@google.com>
2015-11-20 23:34:12 +00:00
David Benjamin
d28f59c27b Switch the keylog BIO to a callback.
The keylog BIO is internally synchronized by the SSL_CTX lock, but an
application may wish to log keys from multiple SSL_CTXs. This is in
preparation for switching Chromium to use a separate SSL_CTX per profile
to more naturally split up the session caches.

It will also be useful for routing up SSLKEYLOGFILE in WebRTC. There,
each log line must be converted to an IPC up from the renderer
processes.

This will require changes in Chromium when we roll BoringSSL.

BUG=458365,webrtc:4417

Change-Id: I2945bdb4def0a9c36e751eab3d5b06c330d66b54
Reviewed-on: https://boringssl-review.googlesource.com/6514
Reviewed-by: Adam Langley <agl@google.com>
2015-11-19 01:23:49 +00:00
David Benjamin
af07365b49 Check for overflow when parsing a CBS with d2i_*.
Until we've done away with the d2i_* stack completely, boundaries need
to be mindful of the type mismatch. d2i_* takes a long, not a size_t.

Change-Id: If02f9ca2cfde02d0929ac18275d09bf5df400f3a
Reviewed-on: https://boringssl-review.googlesource.com/6491
Reviewed-by: Adam Langley <agl@google.com>
2015-11-16 23:17:42 +00:00
David Benjamin
cd24a39f1b Limit DHE groups to 4096-bit.
dh.c had a 10k-bit limit but it wasn't quite correctly enforced. However,
that's still 1.12s of jank on the IO thread, which is too long. Since the SSL
code consumes DHE groups from the network, it should be responsible for
enforcing what sanity it needs on them.

Costs of various bit lengths on 2013 Macbook Air:
1024 - 1.4ms
2048 - 14ms
3072 - 24ms
4096 - 55ms
5000 - 160ms
10000 - 1.12s

UMA says that DHE groups are 0.2% 4096-bit and otherwise are 5.5% 2048-bit and
94% 1024-bit and some noise. Set the limit to 4096-bit to be conservative,
although that's already quite a lot of jank.

BUG=554295

Change-Id: I8e167748a67e4e1adfb62d73dfff094abfa7d215
Reviewed-on: https://boringssl-review.googlesource.com/6464
Reviewed-by: Adam Langley <agl@google.com>
2015-11-11 22:18:39 +00:00
David Benjamin
99fdfb9f22 Move curve check out of tls12_check_peer_sigalg.
The current check has two problems:

- It only runs on the server, where there isn't a curve list at all. This was a
  mistake in https://boringssl-review.googlesource.com/1843 which flipped it
  from client-only to server-only.

- It only runs in TLS 1.2, so one could bypass it by just negotiating TLS 1.1.
  Upstream added it as part of their Suite B mode, which requires 1.2.

Move it elsewhere. Though we do not check the entire chain, leaving that to the
certificate verifier, signatures made by the leaf certificate are made by the
SSL/TLS stack, so it's reasonable to check the curve as part of checking
suitability of a leaf.

Change-Id: I7c12f2a32ba946a20e9ba6c70eff23bebcb60bb2
Reviewed-on: https://boringssl-review.googlesource.com/6414
Reviewed-by: Adam Langley <agl@google.com>
2015-11-11 22:15:16 +00:00
David Benjamin
6e80765774 Add SSL_get_server_key_exchange_hash.
This exposes the ServerKeyExchange signature hash type used in the most recent
handshake, for histogramming on the client.

BUG=549662

Change-Id: I8a4e00ac735b1ecd2c2df824112c3a0bc62332a7
Reviewed-on: https://boringssl-review.googlesource.com/6413
Reviewed-by: Adam Langley <agl@google.com>
2015-11-06 22:35:28 +00:00
David Benjamin
c7817d8ce2 Add SSL_CIPHER_get_min_version and tidy up SSL_TLSV1_2 logic.
Later when TLS 1.3 comes around, we'll need SSL_CIPHER_get_max_version too. In
the meantime, hide the SSL_TLSV1_2 messiness behind a reasonable API.

Change-Id: Ibcc17cccf48dd99e364d6defdfa5a87d031ecf0a
Reviewed-on: https://boringssl-review.googlesource.com/6452
Reviewed-by: Adam Langley <agl@google.com>
2015-11-06 19:56:29 +00:00
Adam Langley
09d68c98c0 Expand a comment.
As a follow up to https://boringssl-review.googlesource.com/#/c/6340,
this change expands a comment to note the reason for clearing a flag
that I missed.

Change-Id: Ib3cfecbb330f0ae7c46bf44286f4e6b407159fe8
Reviewed-on: https://boringssl-review.googlesource.com/6393
Reviewed-by: Adam Langley <agl@google.com>
2015-11-03 01:15:55 +00:00
David Benjamin
13e81fc971 Fix DTLS asynchronous write handling.
Although the DTLS transport layer logic drops failed writes on the floor, it is
actually set up to work correctly. If an SSL_write fails at the transport,
dropping the buffer is fine. Arguably it works better than in TLS because we
don't have the weird "half-committed to data" behavior. Likewise, the handshake
keeps track of how far its gotten and resumes the message at the right point.

This broke when the buffering logic was rewritten because I didn't understand
what the DTLS code was doing. The one thing that doesn't work as one might
expect is non-fatal write errors during rexmit are not recoverable. The next
timeout must fire before we try again.

This code is quite badly sprinkled in here, so add tests to guard it against
future turbulence. Because of the rexmit issues, the tests need some hacks
around calls which may trigger them. It also changes the Go DTLS implementation
from being completely strict about sequence numbers to only requiring they be
monotonic.

The tests also revealed another bug. This one seems to be upstream's fault, not
mine. The logic to reset the handshake hash on the second ClientHello (in the
HelloVerifyRequest case) was a little overenthusiastic and breaks if the
ClientHello took multiple tries to send.

Change-Id: I9b38b93fff7ae62faf8e36c4beaf848850b3f4b9
Reviewed-on: https://boringssl-review.googlesource.com/6417
Reviewed-by: Adam Langley <agl@google.com>
2015-11-02 23:16:22 +00:00
Brian Smith
274341dd6e Change the type of |EC_GROUP_get_degree| and friends to |unsigned|.
These functions ultimately return the result of |BN_num_bits|, and that
function's return type is |unsigned|. Thus, these functions' return
type should also be |unsigned|.

Change-Id: I2cef63e6f75425857bac71f7c5517ef22ab2296b
Reviewed-on: https://boringssl-review.googlesource.com/6170
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-27 16:48:04 +00:00
David Benjamin
1269ddd377 Never use the internal session cache for a client.
The internal session cache is keyed on session ID, so this is completely
useless for clients (indeed we never look it up internally). Along the way,
tidy up ssl_update_cache to be more readable. The slight behavior change is
that SSL_CTX_add_session's return code no longer controls the external
callback. It's not clear to me what that could have accomplished. (It can only
fail on allocation error. We only call it for new sessions, so the duplicate
case is impossible.)

The one thing of value the internal cache might have provided is managing the
timeout. The SSL_CTX_flush_sessions logic would flip the not_resumable bit and
cause us not to offer expired sessions (modulo SSL_CTX_flush_sessions's delay
and any discrepancies between the two caches). Instead, just check expiration
when deciding whether or not to offer a session.

This way clients that set SSL_SESS_CACHE_CLIENT blindly don't accidentally
consume gobs of memory.

BUG=531194

Change-Id: If97485beab21874f37737edc44df24e61ce23705
Reviewed-on: https://boringssl-review.googlesource.com/6321
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-26 19:27:28 +00:00
David Benjamin
dc2aea2231 Remove all the logic around custom session IDs and retrying on collisions.
A random 32-byte (so 256-bit) session ID is never going to collide with
an existing one. (And, if it does, SSL_CTX_add_session does account for
this, so the server won't explode. Just attempting to resume some
session will fail.)

That logic didn't completely work anyway as it didn't account for
external session caches or multiple connections picking the same ID in
parallel (generation and insertion happen at different times) or
multiple servers sharing one cache. In theory one could fix this by
passing in a sufficiently clever generate_session_id, but no one does
that.

I found no callers of these functions, so just remove them altogether.

Change-Id: I8500c592cf4676de6d7194d611b99e9e76f150a7
Reviewed-on: https://boringssl-review.googlesource.com/6318
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-26 19:00:14 +00:00
David Benjamin
82170248e7 Document the info callback.
This callback is some combination of arguably useful stuff (bracket
handshakes, alerts) and completely insane things (find out when the
state machine advances). Deprecate the latter.

Change-Id: Ibea5b32cb360b767b0f45b302fd5f1fe17850593
Reviewed-on: https://boringssl-review.googlesource.com/6305
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-26 18:12:22 +00:00
David Benjamin
dd6fed9704 Explicitly handle empty NewSessionTickets on the client.
RFC 5077 explicitly allows the server to change its mind and send no
ticket by sending an empty NewSessionTicket. See also upstream's
21b538d616b388fa0ce64ef54da3504253895cf8.

CBS_stow handles this case somewhat, so we won't get confused about
malloc(0) as upstream did. But we'll still fill in a bogus SHA-256
session ID, cache the session, and send a ClientHello with bogus session
ID but empty ticket extension. (The session ID field changes meaning
significantly when the ticket is or isn't empty. Non-empty means "ignore
the session ID, but echo if it resuming" while empty means "I support
tickets, but am offering this session ID".

The other behavior change is that a server which changes its mind on a
resumption handshake will no longer override the client's session cache
with a ticket-less session.

(This is kind of silly. Given that we don't get completely confused due
to CBS_stow, it might not be worth bothering with the rest. Mostly it
bugged me that we send an indicator session ID with no ticket.)

Change-Id: Id6b5bde1fe51aa3e1f453a948e59bfd1e2502db6
Reviewed-on: https://boringssl-review.googlesource.com/6340
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-26 17:44:54 +00:00
David Benjamin
79a0589dc4 Ditch remaining filename comments from public headers and ssl/
Change-Id: I8fc795d18aacb0c929b82e7d58514b22103e2106
Reviewed-on: https://boringssl-review.googlesource.com/6292
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-20 18:40:05 +00:00
David Benjamin
96e97b1bf1 Convert ssl3_send_channel_id to CBB.
In doing so, simplify the mess around serializing the public key.
Channel ID specifies that you write x and y concatenated. Rather than
using the X9.62 serialization and chopping bits off, get the affine
coordinates and write them out in the same way we write r and s.

Also unify the P-256 sanity check around SSL_set1_tls_channel_id and
actually check the curve NID.

BUG=468889

Change-Id: I228877b736c9722e368d315064ce3ae6893adfc0
Reviewed-on: https://boringssl-review.googlesource.com/6201
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-20 18:16:46 +00:00
David Benjamin
e97b96224c Convert ssl3_send_next_proto to CBB.
BUG=468889

Change-Id: I841b2816ba47c8c1129e333012272902a52cafd3
Reviewed-on: https://boringssl-review.googlesource.com/6200
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-20 18:08:28 +00:00
David Benjamin
e8d53508ca Convert ssl3_send_client_hello to CBB.
Start converting the ones we can right now. Some of the messier ones
resize init_buf rather than assume the initial size is sufficient, so
those will probably wait until init_buf is gone and the handshake's
undergone some more invasive surgery. The async ones will also require
some thought. But some can be incrementally converted now.

BUG=468889

Change-Id: I0bc22e4dca37d9d671a488c42eba864c51933638
Reviewed-on: https://boringssl-review.googlesource.com/6190
Reviewed-by: Adam Langley <alangley@gmail.com>
2015-10-20 17:56:19 +00:00
David Benjamin
fd8e69f26d Better document the callbacks around client certificates.
Deprecate the client_cert_cb variant since you can't really configure
intermediates with it. (You might be able to by configuring the
intermediates without the leaf or key and leaving the SSL stack to
configure those, but that's really weird. cert_cb is simpler.)

Also document the two functions the callbacks may use to query the
CertificateRequest on the client.

Change-Id: Iad6076266fd798cd74ea4e09978e7f5df5c8a670
Reviewed-on: https://boringssl-review.googlesource.com/6092
Reviewed-by: Adam Langley <agl@google.com>
2015-10-13 18:18:40 +00:00
Steven Valdez
0d62f26c36 Adding more options for signing digest fallback.
Allow configuring digest preferences for the private key. Some
smartcards have limited support for signing digests, notably Windows
CAPI keys and old Estonian smartcards. Chromium used the supports_digest
hook in SSL_PRIVATE_KEY_METHOD to limit such keys to SHA1. However,
detecting those keys was a heuristic, so some SHA256-capable keys
authenticating to SHA256-only servers regressed in the switch to
BoringSSL. Replace this mechanism with an API to configure digest
preference order. This way heuristically-detected SHA1-only keys may be
configured by Chromium as SHA1-preferring rather than SHA1-requiring.

In doing so, clean up the shared_sigalgs machinery somewhat.

BUG=468076

Change-Id: I996a2df213ae4d8b4062f0ab85b15262ca26f3c6
Reviewed-on: https://boringssl-review.googlesource.com/5755
Reviewed-by: Adam Langley <agl@google.com>
2015-09-23 21:55:01 +00:00
David Benjamin
9e4e01ee14 Align the SSL stack on #include style.
ssl.h should be first. Also two lines after includes and the rest of the
file.

Change-Id: Icb7586e00a3e64170082c96cf3f8bfbb2b7e1611
Reviewed-on: https://boringssl-review.googlesource.com/5892
Reviewed-by: Adam Langley <agl@google.com>
2015-09-15 23:32:07 +00:00