Commit Graph

3081 Commits

Author SHA1 Message Date
David Benjamin
156edfe536 Switch Windows CRYPTO_MUTEX implementation to SRWLOCK.
Now that we no longer support Windows XP, this is available.
Unfortunately, the public header version of CRYPTO_MUTEX means we
still can't easily merge CRYPTO_MUTEX and CRYPTO_STATIC_MUTEX.

BUG=37

Change-Id: If309de3f06e0854c505083b72fd64d1dbb3f4563
Reviewed-on: https://boringssl-review.googlesource.com/8081
Reviewed-by: Adam Langley <agl@google.com>
2016-05-31 21:11:36 +00:00
David Benjamin
29270dea85 Split unlock functions into read/write variants.
Windows SRWLOCK requires you call different functions here. Split
them up in preparation for switching Windows from CRITICAL_SECTION.

BUG=37

Change-Id: I7b5c6a98eab9ae5bb0734b805cfa1ff334918f35
Reviewed-on: https://boringssl-review.googlesource.com/8080
Reviewed-by: Adam Langley <agl@google.com>
2016-05-31 21:09:29 +00:00
Matt Braithwaite
053931e74e CECPQ1: change from named curve to ciphersuite.
This is easier to deploy, and more obvious.  This commit reverts a few
pieces of e25775bc, but keeps most of it.

Change-Id: If8d657a4221c665349c06041bb12fffca1527a2c
Reviewed-on: https://boringssl-review.googlesource.com/8061
Reviewed-by: Adam Langley <agl@google.com>
2016-05-26 19:42:35 +00:00
Adam Langley
d09175ffe3 Replace base64 decoding.
This code has caused a long history of problems. This change rewrites it
completely with something that is, hopefully, much simplier and robust
and adds more testing.

Change-Id: Ibeef51f9386afd95d5b73316e451eb3a2d7ec4e0
Reviewed-on: https://boringssl-review.googlesource.com/8033
Reviewed-by: Adam Langley <agl@google.com>
2016-05-26 17:59:10 +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
Steven Valdez
494650cfcf Adding TLS 1.3 AEAD construction.
The TLS 1.3 spec has an explicit nonce construction for AEADs that
requires xoring the IV and sequence number.

Change-Id: I77145e12f7946ffb35ebeeb9b2947aa51058cbe9
Reviewed-on: https://boringssl-review.googlesource.com/8042
Reviewed-by: Adam Langley <agl@google.com>
2016-05-25 18:04:24 +00:00
Steven Valdez
4f94b1c19f Adding TLS 1.3 constants.
Constants representing TLS 1.3 are added to allow for future work to be
flagged on TLS1_3_VERSION. To prevent BoringSSL from negotiating the
non-existent TLS 1.3 version, it is explicitly disabled using
SSL_OP_NO_TLSv1_3.

Change-Id: Ie5258a916f4c19ef21646c4073d5b4a7974d6f3f
Reviewed-on: https://boringssl-review.googlesource.com/8041
Reviewed-by: Adam Langley <agl@google.com>
2016-05-25 17:41:36 +00:00
Steven Valdez
1eca1d3816 Renaming Channel ID Encrypted Extensions.
This renames the Channel ID EncryptedExtensions message to allow for
compatibility with TLS 1.3 EncryptedExtensions.

Change-Id: I5b67d00d548518045554becb1b7213fba86731f2
Reviewed-on: https://boringssl-review.googlesource.com/8040
Reviewed-by: Adam Langley <agl@google.com>
2016-05-23 20:37:04 +00:00
David Benjamin
2f87112b96 Never expose ssl->bbio in the public API.
OpenSSL's bbio logic is kind of crazy. It would be good to eventually do the
buffering in a better way (notably, bbio is fragile, if not outright broken,
for DTLS). In the meantime, this fixes a number of bugs where the existence of
bbio was leaked in the public API and broke things.

- SSL_get_wbio returned the bbio during the handshake. It must always return
  the BIO the consumer configured. In doing so, internal accesses of
  SSL_get_wbio should be switched to ssl->wbio since those want to see bbio.
  For consistency, do the same with rbio.

- The logic in SSL_set_rfd, etc. (which I doubt is quite right since
  SSL_set_bio's lifetime is unclear) would get confused once wbio got wrapped.
  Those want to compare to SSL_get_wbio.

- If SSL_set_bio was called mid-handshake, bbio would get disconnected and lose
  state. It forgets to reattach the bbio afterwards. Unfortunately, Conscrypt
  does this a lot. It just never ended up calling it at a point where the bbio
  would cause problems.

- Make more explicit the invariant that any bbio's which exist are always
  attached. Simplify a few things as part of that.

Change-Id: Ia02d6bdfb9aeb1e3021a8f82dcbd0629f5c7fb8d
Reviewed-on: https://boringssl-review.googlesource.com/8023
Reviewed-by: Kenny Root <kroot@google.com>
Reviewed-by: Adam Langley <agl@google.com>
2016-05-23 18:15:03 +00:00
David Benjamin
7e7a82d962 Rename GetConfigPtr to GetTestConfig.
GetConfigPtr was a silly name. GetTestConfig matches the type and GetTestState.

Change-Id: I9998437a7be35dbdaab6e460954acf1b95375de0
Reviewed-on: https://boringssl-review.googlesource.com/8024
Reviewed-by: Adam Langley <agl@google.com>
2016-05-23 15:34:02 +00:00
Adam Langley
7fcfd3b37a Add ISC license to Go files that were missing a license.
Change-Id: I1fe3bed7d5c577748c9f4c3ccd5c1b90fec3d7d7
Reviewed-on: https://boringssl-review.googlesource.com/8032
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-20 18:11:38 +00:00
Steven Valdez
ce902a9bcd Generalizing curves to groups in preparation for TLS 1.3.
The 'elliptic_curves' extension is being renamed to 'supported_groups'
in the TLS 1.3 draft, and most of the curve-specific methods are
generalized to groups/group IDs.

Change-Id: Icd1a1cf7365c8a4a64ae601993dc4273802610fb
Reviewed-on: https://boringssl-review.googlesource.com/7955
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-20 17:43:11 +00:00
Steven Valdez
f1012b5c31 Fix HKDF leak.
Change-Id: Ia83935420d38ededa699aa7f8011a2e358f6c4d3
Reviewed-on: https://boringssl-review.googlesource.com/8022
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-20 15:42:01 +00:00
David Benjamin
2b1ca80e09 Link back to the main page in documentation.
Also give the main page a title.

Change-Id: I6db588a9454d90a5974de5446d58d709f84d1906
Reviewed-on: https://boringssl-review.googlesource.com/8020
Reviewed-by: Adam Langley <agl@google.com>
2016-05-20 15:36:00 +00:00
Adam Langley
1aa03f0745 Add |EVP_dss1| as an alias for |EVP_sha1| in decrepit.
Change-Id: I51fa744c367d1f0c7044050f99c4992778e649bd
Reviewed-on: https://boringssl-review.googlesource.com/8030
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-20 15:31:52 +00:00
Adam Langley
7cb920b6ac Include crypto.h from pem.h.
open_iscsi assumes that it can get |OPENSSL_malloc| after including only
pem.h and err.h. Since pem.h already includes quite a lot, this change
adds crypto.h to that set so that open_iscsi is happy.

Change-Id: I6dc06c27088ce3ca46c1ab53bb29650033cba267
Reviewed-on: https://boringssl-review.googlesource.com/8031
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-20 15:31:26 +00:00
Steven Valdez
3686584d16 Separating HKDF into HKDFExtract and HKDFExpand.
The key schedule in TLS 1.3 requires a separate Extract and Expand phase
for the cryptographic computations.

Change-Id: Ifdac1237bda5212de5d4f7e8db54e202151d45ec
Reviewed-on: https://boringssl-review.googlesource.com/7983
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-20 15:17:17 +00:00
Matt Braithwaite
e25775bcac Elliptic curve + post-quantum key exchange
CECPQ1 is a new key exchange that concatenates the results of an X25519
key agreement and a NEWHOPE key agreement.

Change-Id: Ib919bdc2e1f30f28bf80c4c18f6558017ea386bb
Reviewed-on: https://boringssl-review.googlesource.com/7962
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-19 22:19:14 +00:00
David Benjamin
61d4cdc03d No-op change to kick the bots.
Let's see if the Android bots work!

Change-Id: Ic4a52edcb441c26bc87d776984466e04cff93ae3
2016-05-19 17:55:36 -04:00
nmittler
f0322b2abc Use non-deprecated methods on windows.
Use of strdup, close, lseek, read, and write prevent linking
statically againt libcmt.lib.

Change-Id: I04f7876ec0f03f29f000bbcc6b2ccdec844452d2
Reviewed-on: https://boringssl-review.googlesource.com/8010
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-19 20:30:50 +00:00
Matt Braithwaite
e09e579603 Rename NEWHOPE functions to offer/accept/finish.
This is consistent with the new convention in ssl_ecdh.c.

Along the way, change newhope_test.c to not iterate 1000 times over each
test.

Change-Id: I7a500f45b838eba8f6df96957891aa8e880ba089
Reviewed-on: https://boringssl-review.googlesource.com/8012
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-19 18:17:48 +00:00
David Benjamin
1147be052c Inherit the parent environment when shelling out to Go.
The recipes need to run with a funny GOROOT and we were clearing the
environment.

BUG=26

Change-Id: If233a16e060533ad3fa6f215ce596456c2d7afa5
Reviewed-on: https://boringssl-review.googlesource.com/7988
Reviewed-by: Adam Langley <agl@google.com>
2016-05-19 18:13:31 +00:00
David Benjamin
3ccf4d6d65 Pull Chromium's android_tools as an android-only dependency.
This will be used by the bots to get adb and the NDK.

BUG=26

Change-Id: Iae07a380c49b4990f0aa7d73c4f0b399924b9784
Reviewed-on: https://boringssl-review.googlesource.com/7986
Reviewed-by: Adam Langley <agl@google.com>
2016-05-19 16:58:13 +00:00
David Benjamin
75021b747f Update Android build instructions.
We now have a copy of android-cmake. Also remove the mention of running cmake
twice. It seems to work fine once?

The API level also got specified twice somehow.

BUG=26

Change-Id: I1331b079a4d8531cd53f7de3605ac318c14b3e26
Reviewed-on: https://boringssl-review.googlesource.com/7985
Reviewed-by: Adam Langley <agl@google.com>
2016-05-19 16:56:25 +00:00
David Benjamin
f07ba17942 Check in a copy of android-cmake.
BUG=26

Change-Id: I2f95740afdbc3bdb0676626679a30f1e1cc307d6
Reviewed-on: https://boringssl-review.googlesource.com/7984
Reviewed-by: Adam Langley <agl@google.com>
2016-05-19 16:55:25 +00:00
David Benjamin
00b1069a6b Add an option to pick a different adb binary.
This will let the recipes use the copy pulled from Chromium's android_tools.

BUG=26

Change-Id: Ica6519223b9fb6daef30f3e14c72ef6422de0f6c
Reviewed-on: https://boringssl-review.googlesource.com/7982
Reviewed-by: Adam Langley <agl@google.com>
2016-05-19 16:55:02 +00:00
Tamas Berghammer
5693e42ae4 Fix discovery rule for perl and go for Android
We don't use find_package/find_program on android to find go/perl
because the android toolchain reconfigure the $PATH. The pervious
way of solving this was to let ninja look for go/perl on the $PATH
but this approach prevented us from specifying explicit go/perl
executables what is needed for hermetic build using prebuilts. This
CL changes the Android specific discovery rule to only set
GO_EXECUTABLE and PERL_EXECUTABLE if they are not specified on the
command line or inside the toolchain file.

Change-Id: Ib6ef69707749073f2b79244ebb301502b2a5a34a
Reviewed-on: https://boringssl-review.googlesource.com/8000
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-19 14:46:02 +00:00
David Benjamin
ea77107e9a Remove references to non-existent BIO functions.
We don't have any of these.

Change-Id: I8d12284fbbab0ff35ac32d35a5f2eba326ab79f8
Reviewed-on: https://boringssl-review.googlesource.com/7981
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-18 23:41:08 +00:00
Matt Braithwaite
c82b70155d Go version of New Hope post-quantum key exchange.
(Code mostly due to agl.)

Change-Id: Iec77396141954e5f8e845cc261eadab77f551f08
Reviewed-on: https://boringssl-review.googlesource.com/7990
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 22:30:20 +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
fce37b0deb Add a TODO for why init_buf isn't released post-handshake.
There is no good reason why this needs to be this way. Later work should make
this all use a much more appropriate design. In the meantime, leave a note here
so this does not look accidental.

Change-Id: I7599dea7a474f54e26d9ab175b0e3cada99a974d
Reviewed-on: https://boringssl-review.googlesource.com/7951
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 20:52:19 +00:00
David Benjamin
1d64afda44 Stop reseting init_num everywhere in the handshake loop.
This was needed because ssl3_get_message would get confused if init_num were
not set back to zero when reading the next message. However, ssl3_get_message
now treats init_num only as an output, not an input. (The message sending logic
and the individual handshake states still use it, so we can't get rid of it
altogether yet.)

I've kept the init_num reset at the start and end of the handshake loop alone
for now since that's more about initialization and cleanup. Though I believe
they too do not do anything.

Change-Id: I64bbdd82122498de32364e7edb3b00b166059ecd
Reviewed-on: https://boringssl-review.googlesource.com/7950
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 20:52:04 +00:00
David Benjamin
1e6d6df943 Remove state parameters to ssl3_get_message.
They're completely unused now. The handshake message reassembly logic should
not depend on the state machine. This should partially free it up (ugly as it
is) to be shared with a future TLS 1.3 implementation while, in parallel, it
and the layers below, get reworked. This also cuts down on the number of states
significantly.

Partially because I expect we'd want to get ssl_hash_message_t out of there
too. Having it in common code is fine, but it needs to be in the (supposed to
be) protocol-agnostic handshake state machine, not the protocol-specific
handshake message layer.

Change-Id: I12f9dc57bf433ceead0591106ab165d352ef6ee4
Reviewed-on: https://boringssl-review.googlesource.com/7949
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 20:51:48 +00:00
David Benjamin
a6338be3fa Simplify ssl3_get_message.
Rather than this confusing coordination with the handshake state machine and
init_num changing meaning partway through, use the length field already in
BUF_MEM. Like the new record layer parsing, is no need to keep track of whether
we are reading the header or the body. Simply keep extending the handshake
message until it's far enough along.

ssl3_get_message still needs tons of work, but this allows us to disentangle it
from the handshake state.

Change-Id: Ic2b3e7cfe6152a7e28a04980317d3c7c396d9b08
Reviewed-on: https://boringssl-review.googlesource.com/7948
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 20:50:57 +00:00
David Benjamin
1f9329aaf5 Add BUF_MEM_reserve.
BUF_MEM is actually a rather silly API for the SSL stack. There's separate
length and max fields, but init_buf effectively treats length as max and max as
nothing.

We possibly don't want to be using it long-term anyway (if nothing else, the
char*/uint8_t* thing is irritating), but in the meantime, it'll be easier to
separately fix up get_message's book-keeping and state tracking from where the
handshake gets its messages from.

Change-Id: I9e56ea008173991edc8312ec707505ead410a9ee
Reviewed-on: https://boringssl-review.googlesource.com/7947
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 19:09:06 +00:00
David Benjamin
4d559617cd Unflake Unclean-Shutdown-Alert on Windows.
On Windows, if we write to our socket and then close it, the peer sometimes
doesn't get all the data. This was working for our shimShutsDown tests because
we send close_notify in parallel with the peer and sendAlert(alertCloseNotify)
did not internally return an error.

For convenience, sendAlert returns a local error for non-close_notify alerts.
Suppress that error to avoid the race condition. This makes it behave like the
other shimShutsDown tests.

Change-Id: Iad256e3ea5223285793991e2eba9c7d61f2e3ddf
Reviewed-on: https://boringssl-review.googlesource.com/7980
Reviewed-by: Adam Langley <agl@google.com>
2016-05-18 18:59:38 +00:00
Matt Braithwaite
f4ce8e5324 Refactor ECDH key exchange to make it asymmetrical
Previously, SSL_ECDH_METHOD consisted of two methods: one to produce a
public key to be sent to the peer, and another to produce the shared key
upon receipt of the peer's message.

This API does not work for NEWHOPE, because the client-to-server message
cannot be produced until the server's message has been received by the
client.

Solve this by introducing a new method which consumes data from the
server key exchange message and produces data for the client key
exchange message.

Change-Id: I1ed5a2bf198ca2d2ddb6d577888c1fa2008ef99a
Reviewed-on: https://boringssl-review.googlesource.com/7961
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-18 18:09:26 +00:00
David Benjamin
68a533c0ef Fix line-number counting in doc.go.
There's an off-by-one when skipping blank lines. The initial logic also has an
off-by-one but since it starts lineNo 0-based and then switches to 1-based, it
cancels out.

The decl error line number also was not of where the decl began.

Change-Id: I58fd157dad3276cb9de52ac48ff8c7c73e40f337
Reviewed-on: https://boringssl-review.googlesource.com/7959
Reviewed-by: Adam Langley <agl@google.com>
2016-05-17 21:57:16 +00:00
David Benjamin
7f6706ce64 MSVC doesn't like C bitfields.
Change-Id: I88a415e3dd7ac9ea2fa83ca3e4d835efefa7fcc6
Reviewed-on: https://boringssl-review.googlesource.com/7970
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-17 21:50:45 +00:00
David Benjamin
47f5a1feca Allow documentation comments to begin with A/An.
This aligns with Go style.

Change-Id: I773c6a2e8ddd8d40a8480efae86736c4b338d203
Reviewed-on: https://boringssl-review.googlesource.com/7958
Reviewed-by: Adam Langley <agl@google.com>
2016-05-17 21:40:47 +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
Adam Langley
f448c60903 Update INCORPORATING.md to clarify one point.
In practice it seems that it's not clear that consumers of BoringSSL
generally check in the generated files.

Change-Id: Iaa03aa62139bbcf3e7e7f68662073854954b835f
Reviewed-on: https://boringssl-review.googlesource.com/7956
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-17 19:39:55 +00:00
Adam Langley
4fac8d0eae Add CRYPTO_has_asm.
This function will return whether BoringSSL was built with
OPENSSL_NO_ASM. This will allow us to write a test in our internal
codebase which asserts that normal builds should always have assembly
code included.

Change-Id: Ib226bf63199022f0039d590edd50c0cc823927b9
Reviewed-on: https://boringssl-review.googlesource.com/7960
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-17 19:03:31 +00:00
David Benjamin
c032dfa27e Client auth is only legal in certificate-based ciphers.
OpenSSL used to only forbid it on the server in plain PSK and allow it on the
client. Enforce it properly on both sides. My read of the rule in RFC 5246 ("A
non-anonymous server can optionally request a certificate") and in RFC 4279
("The Certificate and CertificateRequest payloads are omitted from the
response.") is that client auth happens iff we're certificate-based.

The line in RFC 4279 is under the plain PSK section, but that doesn't make a
whole lot of sense and there is only one diagram. PSK already authenticates
both sides. I think the most plausible interpretation is that this is for
certificate-based ciphers.

Change-Id: If195232c83f21e011e25318178bb45186de707e6
Reviewed-on: https://boringssl-review.googlesource.com/7942
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-13 20:07:16 +00:00
David Benjamin
060cfb0911 Simplify handshake message size limits.
A handshake message can go up to 2^24 bytes = 16MB which is a little large for
the peer to force us to buffer. Accordingly, we bound the size of a
handshake message.

Rather than have a global limit, the existing logic uses a different limit at
each state in the handshake state machine and, for certificates, allows
configuring the maximum certificate size. This is nice in that we engage larger
limits iff the relevant state is reachable from the handshake. Servers without
client auth get a tighter limit "for free".

However, this doesn't work for DTLS due to out-of-order messages and we use a
simpler scheme for DTLS. This scheme also is tricky on optional messages and
makes the handshake <-> message layer communication complex.

Apart from an ignored 20,000 byte limit on ServerHello, the largest
non-certificate limit is the common 16k limit on ClientHello. So this
complexity wasn't buying us anything. Unify everything on the DTLS scheme
except, so as not to regress bounds on client-auth-less servers, also correctly
check for whether client auth is configured. The value of 16k was chosen based
on this value.

(The 20,000 byte ServerHello limit makes no sense. We can easily bound the
ServerHello because servers may not send extensions we don't implement. But it
gets overshadowed by the certificate anyway.)

Change-Id: I00309b16d809a3c2a1543f99fd29c4163e3add81
Reviewed-on: https://boringssl-review.googlesource.com/7941
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-13 20:06:24 +00:00
Brian Smith
4e7a1ff055 Remove unuseful comments in |BN_mod_exp|.
The performance measurements seem to be very out-of-date. Also, the
idea for optimizing the case of an even modulus is interesting, but it
isn't useful because we never use an even modulus.

Change-Id: I012eb37638cda3c63db0e390c8c728f65b949e54
Reviewed-on: https://boringssl-review.googlesource.com/7733
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-13 19:10:47 +00:00
Brian Smith
448fa42779 Deprecate |BN_mod_exp2_mont| and simplify its implementation.
This function is only really useful for DSA signature verification,
which is something that isn't performance-sensitive. Replace its
optimized implementation with a naïve implementation that's much
simpler.

Note that it would be simpler to use |BN_mod_mul| in the new
implementation; |BN_mod_mul_montgomery| is used instead only to be
consistent with other work being done to replace uses of non-Montgomery
modular reduction with Montgomery modular reduction.

Change-Id: If587d463b73dd997acfc5b7ada955398c99cc342
Reviewed-on: https://boringssl-review.googlesource.com/7732
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-13 19:10:18 +00:00