Commit Graph

162 Commits

Author SHA1 Message Date
David Benjamin
1f61f0d7c3 Implement TLS 1.3's downgrade signal.
For now, skip the 1.2 -> 1.1 signal since that will affect shipping
code. We may as well enable it too, but wait until things have settled
down. This implements the version in draft-14 since draft-13's isn't
backwards-compatible.

Change-Id: I46be43e6f4c5203eb4ae006d1c6a2fe7d7a949ec
Reviewed-on: https://boringssl-review.googlesource.com/8724
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-12 19:17:43 +00:00
David Benjamin
1fb125c74a Enforce ECDSA curve matching in TLS 1.3.
Implement in both C and Go. To test this, route config into all the
sign.go functions so we can expose bugs to skip the check.

Unfortunately, custom private keys are going to be a little weird since
we can't check their curve type. We may need to muse on what to do here.
Perhaps the key type bit should return an enum that includes the curve?
It's weird because, going forward, hopefully all new key types have
exactly one kind of signature so key type == sig alg == sig alg prefs.

Change-Id: I1f487ec143512ead931e3392e8be2a3172abe3d2
Reviewed-on: https://boringssl-review.googlesource.com/8701
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-12 18:40:08 +00:00
David Benjamin
887c300e25 Move the key type check from tls12_check_peer_sigalg to ssl_verify_*.
ssl_verify_* already ought to be checking this, so there's only a need
to check against the configured preferences.

Change-Id: I79bc771969c57f953278e622084641e6e20108e3
Reviewed-on: https://boringssl-review.googlesource.com/8698
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-12 18:25:05 +00:00
David Benjamin
ea9a0d5313 Refine SHA-1 default in signature algorithm negotiation.
Rather than blindly select SHA-1 if we can't find a matching one, act as
if the peer advertised rsa_pkcs1_sha1 and ecdsa_sha1. This means that we
will fail the handshake if no common algorithm may be found.

This is done in preparation for removing the SHA-1 default in TLS 1.3.

Change-Id: I3584947909d3d6988b940f9404044cace265b20d
Reviewed-on: https://boringssl-review.googlesource.com/8695
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-12 16:32:31 +00:00
David Benjamin
d246b81751 Don't decompose sigalgs in key preferences.
Instead, in SSL_set_private_key_digest_prefs, convert the NID list to a
sigalgs list. We'll need to add a new API later when custom key callers
are ready to start advertising RSA-PSS.

This removes all callers of tls12_get_hash except inside the signing and
verifying functions.

Change-Id: Ie534f3b736c6ac6ebeb0d7770d489f72e3321865
Reviewed-on: https://boringssl-review.googlesource.com/8693
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-12 16:31:20 +00:00
David Benjamin
0aa25bd893 Don't call tls12_get_hash in the server handshake.
Instead have ssl3_cert_verify_hash output the hash, since it already
knows it. Also add a missing EVP_PKEY_CTX_set_signature_md call on the
client half. (Although, the call isn't actually necessary.)

Also remove now unnecessary static assert. Since EVP_md5_sha1 is an
EVP_MD itself, EVP_MAX_MD_SIZE is required to fit it already.

Change-Id: Ief74fdbdf08e9f124679475bafba2f6f1d8fc687
Reviewed-on: https://boringssl-review.googlesource.com/8692
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-12 16:30:10 +00:00
David Benjamin
09eb655e5c Simplify ssl_get_message somewhat.
It still places the current message all over the place, but remove the
bizarre init_num/error/ok split. Now callers get the message length out
of init_num, which mirrors init_msg. Also fix some signedness.

Change-Id: Ic2e97b6b99e234926504ff217b8aedae85ba6596
Reviewed-on: https://boringssl-review.googlesource.com/8690
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-11 23:01:32 +00:00
David Benjamin
528bd26dd9 Don't use init_buf in DTLS.
This machinery is so different between TLS and DTLS that there is no
sense in having them share structures. This switches us to maintaining
the full reassembled message in hm_fragment and get_message just lets
the caller read out of that when ready.

This removes the last direct handshake dependency on init_buf,
ssl3_hash_message.

Change-Id: I4eccfb6e6021116255daead5359a0aa3f4d5be7b
Reviewed-on: https://boringssl-review.googlesource.com/8667
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-11 23:01:11 +00:00
David Benjamin
97718f1437 Move references to init_buf into SSL_PROTOCOL_METHOD.
Both DTLS and TLS still use it, but that will change in the following
commit. This also removes the handshake's knowledge of the
dtls_clear_incoming_messages function.

(It's possible we'll want to get rid of begin_handshake in favor of
allocating it lazily depending on how TLS 1.3 post-handshake messages
end up working out. But this should work for now.)

Change-Id: I0f512788bbc330ab2c947890939c73e0a1aca18b
Reviewed-on: https://boringssl-review.googlesource.com/8666
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-11 18:20:33 +00:00
Steven Valdez
2b8415e8ff Move the Digest/Sign split for SignatureAlgorithms to a lower level.
In order to delay the digest of the handshake transcript and unify
around message-based signing callbacks, a copy of the transcript is kept
around until we are sure there is no certificate authentication.

This removes support for SSL_PRIVATE_KEY_METHOD as a client in SSL 3.0.

Change-Id: If8999a19ca021b4ff439319ab91e2cd2103caa64
Reviewed-on: https://boringssl-review.googlesource.com/8561
Reviewed-by: David Benjamin <davidben@google.com>
2016-07-01 19:01:33 +00:00
David Benjamin
9e68f19e1b Add SSL_get_curve_id and SSL_get_dhe_group_size.
This replaces the old key_exchange_info APIs and does not require the
caller be aware of the mess around SSL_SESSION management. They
currently have the same bugs around renegotiation as before, but later
work to fix up SSL_SESSION tracking will fix their internals.

For consistency with the existing functions, I've kept the public API at
'curve' rather than 'group' for now. I think it's probably better to
have only one name with a single explanation in the section header
rather than half and half. (I also wouldn't be surprised if the IETF
ends up renaming 'group' again to 'key exchange' at some point.  We'll
see what happens.)

Change-Id: I8e90a503bc4045d12f30835c86de64ef9f2d07c8
Reviewed-on: https://boringssl-review.googlesource.com/8565
Reviewed-by: Adam Langley <agl@google.com>
2016-06-30 23:20:34 +00:00
David Benjamin
18a3518e5a Don't allocate a group/curve ID for CECPQ1.
We ended up switching this from a curve to a cipher suite, so the group
ID isn't used. This is in preparation for adding an API for the curve
ID, at which point leaving the protocol constants undefined seems
somewhat bad manners.

Change-Id: Icb8bf4594879dbbc24177551868ecfe89bc2f8c3
Reviewed-on: https://boringssl-review.googlesource.com/8563
Reviewed-by: Adam Langley <agl@google.com>
2016-06-30 22:28:37 +00:00
David Benjamin
b6a0a518a3 Simplify version configuration.
OpenSSL's SSL_OP_NO_* flags allow discontinuous version ranges. This is a
nuisance for two reasons. First it makes it unnecessarily difficult to answer
"are any versions below TLS 1.3 enabled?". Second the protocol does not allow
discontinuous version ranges on the client anyway. OpenSSL instead picks the
first continous range of enabled versions on the client, but not the server.

This is bizarrely inconsistent. It also doesn't quite do this as the
ClientHello sending logic does this, but not the ServerHello processing logic.
So we actually break some invariants slightly. The logic is also cumbersome in
DTLS which kindly inverts the comparison logic.

First, switch min_version/max_version's storage to normalized versions. Next
replace all the ad-hoc version-related functions with a single
ssl_get_version_range function. Client and server now consistently pick a
contiguous range of versions. Note this is a slight behavior change for
servers. Version-range-sensitive logic is rewritten to use this new function.

BUG=66

Change-Id: Iad0d64f2b7a917603fc7da54c9fc6656c5fbdb24
Reviewed-on: https://boringssl-review.googlesource.com/8513
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-30 21:56:01 +00:00
Steven Valdez
f0451ca37d Cleaning up internal use of Signature Algorithms.
The signing logic itself still depends on pre-hashed messages and will be fixed
in later commits.

Change-Id: I901b0d99917c311653d44efa34a044bbb9f11e57
Reviewed-on: https://boringssl-review.googlesource.com/8545
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-29 21:22:25 +00:00
David Benjamin
352d0a9c6c Remove a/b parameters to send_change_cipher_spec.
They're not necessary.

Change-Id: Ifeb3fae73a8b22f88019e6ef9f9ba5e64ed3cfab
Reviewed-on: https://boringssl-review.googlesource.com/8543
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-29 18:50:47 +00:00
Steven Valdez
025638597a Changing representation of signature/hash to use SignatureScheme.
As part of the SignatureAlgorithm change in the TLS 1.3 specification,
the existing signature/hash combinations are replaced with a combined
signature algorithm identifier. This change maintains the existing APIs
while fixing the internal representations. The signing code currently
still treats the SignatureAlgorithm as a decomposed value, which will be
fixed as part of a separate CL.

Change-Id: I0cd1660d74ad9bcf55ce5da4449bf2922660be36
Reviewed-on: https://boringssl-review.googlesource.com/8480
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-28 14:18:53 +00:00
David Benjamin
aad50db45d Stop using the word 'buffer' everywhere.
buffer buffer buffer buffer buffer. At some point, words lose their meaning if
they're used too many times. Notably, the DTLS code can't decide whether a
"buffered message" is an incoming message to be reassembled or an outgoing
message to be (re)transmitted.

Change-Id: Ibdde5c00abb062c603d21be97aff49e1c422c755
Reviewed-on: https://boringssl-review.googlesource.com/8500
Reviewed-by: Adam Langley <agl@google.com>
2016-06-27 22:15:22 +00:00
David Benjamin
7583643569 Disconnect handshake message creation from init_buf.
This allows us to use CBB for all handshake messages. Now, SSL_PROTOCOL_METHOD
is responsible for implementing a trio of CBB-related hooks to assemble
handshake messages.

Change-Id: I144d3cac4f05b6637bf45d3f838673fc5c854405
Reviewed-on: https://boringssl-review.googlesource.com/8440
Reviewed-by: Adam Langley <agl@google.com>
2016-06-27 22:15:01 +00:00
David Benjamin
ec847cea9b Replace the incoming message buffer with a ring buffer.
It has size 7. There's no need for a priority queue structure, especially one
that's O(N^2) anyway.

Change-Id: I7609794aac1925c9bbf3015744cae266dcb79bff
Reviewed-on: https://boringssl-review.googlesource.com/8437
Reviewed-by: Adam Langley <agl@google.com>
2016-06-27 20:12:03 +00:00
David Benjamin
778f57e511 Store only one handshake write sequence number.
The pair was a remnant of some weird statefulness and also ChangeCipherSpec
having a "sequence number" to make the pqueue turn into an array.

Change-Id: Iffd82594314df43934073bd141faee0fc167ed5f
Reviewed-on: https://boringssl-review.googlesource.com/8436
Reviewed-by: Adam Langley <agl@google.com>
2016-06-27 20:11:19 +00:00
David Benjamin
29a83c5a0c Rewrite DTLS outgoing message buffering.
Now that retransitting is a lot less stateful, a lot of surrounding code can
lose statefulness too. Rather than this overcomplicated pqueue structure,
hardcode that a handshake flight is capped at 7 messages (actually, DTLS can
only get up to 6 because we don't support NPN or Channel ID in DTLS) and used a
fixed size array.

This also resolves several TODOs.

Change-Id: I2b54c3441577a75ad5ca411d872b807d69aa08eb
Reviewed-on: https://boringssl-review.googlesource.com/8435
Reviewed-by: Adam Langley <agl@google.com>
2016-06-27 20:10:12 +00:00
David Benjamin
b5eb1958bb Make dtls1_do_handshake_write less stateful.
Now dtls1_do_handshake_write takes in a serialized form of the full message and
writes it. It's a little weird to serialize and deserialize the header a bunch,
but msg_callback requires that we keep the full one around in memory anyway.
Between that and the handshake hash definition, DTLS really wants messages to
mean the assembled header, redundancies and all, so we'll just put together
messages that way.

This also fixes a bug where ssl_do_msg_callback would get passed in garbage
where the header was supposed to be. The buffered messages get sampled before
writing the fragment rather than after.

Change-Id: I4e3b8ce4aab4c4ab4502d5428dfb8f3f729c6ef9
Reviewed-on: https://boringssl-review.googlesource.com/8433
Reviewed-by: Adam Langley <agl@google.com>
2016-06-27 20:08:25 +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
a353cdb671 Wrap MSVC-only warning pragmas in a macro.
There's a __pragma expression which allows this. Android builds us Windows with
MinGW for some reason, so we actually do have to tolerate non-MSVC-compatible
Windows compilers. (Clang for Windows is much more sensible than MinGW and
intentionally mimicks MSVC.)

MinGW doesn't understand MSVC's pragmas and warns a lot. #pragma warning is
safe to suppress, so wrap those to shush them. This also lets us do away with a
few ifdefs.

Change-Id: I1f5a8bec4940d4b2d947c4c1cc9341bc15ec4972
Reviewed-on: https://boringssl-review.googlesource.com/8236
Reviewed-by: Adam Langley <agl@google.com>
2016-06-09 21:29:36 +00:00
David Benjamin
2446db0f52 Require in == out for in-place encryption.
While most of OpenSSL's assembly allows out < in too, some of it doesn't.
Upstream seems to not consider this a problem (or, at least, they're failing to
make a decision on whether it is a problem, so we should assume they'll stay
their course). Accordingly, require aliased buffers to exactly align so we
don't have to keep chasing this down.

Change-Id: I00eb3df3e195b249116c68f7272442918d7077eb
Reviewed-on: https://boringssl-review.googlesource.com/8231
Reviewed-by: Adam Langley <agl@google.com>
2016-06-09 19:49:03 +00:00
David Benjamin
1a01e1fc88 Remove in-place TLS record assembly for now.
Decrypting is very easy to do in-place, but encrypting in-place is a hassle.
The rules actually were wrong due to record-splitting. The aliasing prefix and
the alignment prefix actually differ by 1. Take it out for now in preparation
for tightening the aliasing rules.

If we decide to do in-place encrypt later, probably it'd be more useful to
return header + in-place ciphertext + trailer. (That, in turn, needs a
scatter/gather thing on the AEAD thanks to TLS 1.3's padding and record type
construction.) We may also wish to rethink how record-splitting works here.

Change-Id: I0187d39c541e76ef933b7c2c193323164fd8a156
Reviewed-on: https://boringssl-review.googlesource.com/8230
Reviewed-by: Adam Langley <agl@google.com>
2016-06-09 19:47:44 +00:00
David Benjamin
45d45c1194 Trim the DTLS write code slightly.
Change-Id: I0fb4152ed656a60fae3aa7922652df766d4978d7
Reviewed-on: https://boringssl-review.googlesource.com/8178
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 19:33:20 +00:00
David Benjamin
9f1dc8254e A bit of cleanup post state machine merging.
Reorder states and functions by where they appear in the handshake. Remove
unnecessary hooks on SSL_PROTOCOL_METHOD.

Change-Id: I78dae9cf70792170abed6f38510ce870707e82ff
Reviewed-on: https://boringssl-review.googlesource.com/8184
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 19:24:32 +00:00
David Benjamin
df50eecfbc Fold DTLS server state machine into TLS state machine.
Change-Id: I56d3d625dbe2e338f305bc1332fb0131a20e1c16
Reviewed-on: https://boringssl-review.googlesource.com/8183
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 19:21:14 +00:00
David Benjamin
aa7734b81b Fold the DTLS client handshake into the TLS one.
Change-Id: Ib8b1c646cf1652ee1481fe73589830be8263fc20
Reviewed-on: https://boringssl-review.googlesource.com/8182
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 19:20:02 +00:00
David Benjamin
af62d61df3 Remove dtls1_read_bytes.
It can be folded into dtls1_read_app_data. This code, since it still takes an
output pointer, does not yet process records atomically. (Though, being DTLS,
it probably should...)

Change-Id: I57d60785c9c1dd13b5b2ed158a08a8f5a518db4f
Reviewed-on: https://boringssl-review.googlesource.com/8177
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 19:10:35 +00:00
David Benjamin
c660417bd7 Don't use dtls1_read_bytes to read messages.
This was probably the worst offender of them all as read_bytes is the wrong
abstraction to begin with. Note this is a slight change in how processing a
record works. Rather than reading one fragment at a time, we process all
fragments in a record and return. The intent here is so that all records are
processed atomically since the connection eventually will not be able to retain
a buffer holding the record.

This loses a ton of (though not quite all yet) those a2b macros.

Change-Id: Ibe4bbcc33c496328de08d272457d2282c411b38b
Reviewed-on: https://boringssl-review.googlesource.com/8176
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 19:09:46 +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
15aa895a0b Tidy up the DTLS code's blocking-mode retransmits.
Move this logic out of dtls1_read_bytes and into dtls1_get_record. Only trigger
it when reading from the buffer fails. The other one shouldn't be necessary.
This exists to handle the blocking BIO case when the
BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT signal triggers, so we only need to do it when
timeouts actually trigger.

There also doesn't seem to be a need for most of the machinery. The
BIO_set_flags call seems to be working around a deficiency in the underlying
BIO. There also shouldn't be a need to check the handshake state as there
wouldn't be a timer to restart otherwise.

Change-Id: Ic901ccfb5b82aeb409d16a9d32c04741410ad6d7
Reviewed-on: https://boringssl-review.googlesource.com/8122
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 18:13:42 +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
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
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
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
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
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
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
David Benjamin
c6cc6e76a6 Make kSRTPProfiles static.
It's only used in one file.

Change-Id: I5d60cbc02799b22317f5f7593faf25eb8eea0a24
Reviewed-on: https://boringssl-review.googlesource.com/7943
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-13 14:12:22 +00:00
Taylor Brandstetter
376a0fed24 Adding a method to change the initial DTLS retransmission timer value.
This allows an application to override the default of 1 second, which
is what's instructed in RFC 6347 but is not an absolute requirement.

Change-Id: I0bbb16e31990fbcab44a29325b6ec7757d5789e5
Reviewed-on: https://boringssl-review.googlesource.com/7930
Reviewed-by: David Benjamin <davidben@google.com>
2016-05-11 22:36:26 +00:00
David Benjamin
b095f0f0ca Remove the push argument to ssl_init_wbio_buffer.
Having bbio be tri-state (not allocated, allocated but not active, and
allocated and active) is confusing.

The extra state is only used in the client handshake, where ClientHello is
special-cased to not go through the buffer while everything else is. This dates
to OpenSSL's initial commit and doesn't seem to do much. I do not believe it
can affect renego as the buffer only affects writes; although OpenSSL accepted
interleave on read (though this logic predates it slightly), it never sent
application data while it believed a handshake was active. The handshake would
always be driven to completion first.

My guess is this was to save a copy since the ClientHello is a one-message
flight so it wouldn't need to be buffered? This is probably not worth the extra
variation in the state. (Especially with the DTLS state machine going through
ClientHello twice and pushing the BIO in between the two. Though I suspect that
was a mistake in itself. If the optimization guess is correct, there was no
need to do that.)

Change-Id: I6726f866e16ee7213cab0c3e6abb133981444d47
Reviewed-on: https://boringssl-review.googlesource.com/7873
Reviewed-by: Adam Langley <agl@google.com>
2016-05-06 17:39:48 +00:00
David Benjamin
30152fdfc1 Always buffer DTLS retransmits.
The DTLS bbio logic is rather problematic, but this shouldn't make things
worse. In the in-handshake case, the new code merges the per-message
(unchecked) BIO_flush calls into one call at the end but otherwise the BIO is
treated as is. Otherwise any behavior around non-block writes should be
preserved.

In the post-handshake case, we now install the buffer when we didn't
previously. On write error, the buffer will have garbage in it, but it will be
discarded, so that will preserve any existing retry behavior. (Arguably the
existing retry behavior is a bug, but that's another matter.)

Add a test for all this, otherwise it is sure to regress. Testing for
record-packing is a little fuzzy, but we can assert ChangeCipherSpec always
shares a record with something.

BUG=57

Change-Id: I8603f20811d502c71ded2943b0e72a8bdc4e46f2
Reviewed-on: https://boringssl-review.googlesource.com/7871
Reviewed-by: Adam Langley <agl@google.com>
2016-05-06 17:37:11 +00:00
Adam Langley
d323f4b1e1 Bring back |verify_store|.
This was dropped in d27441a9cb due to lack
of use, but node.js now needs it.

Change-Id: I1e207d4b46fc746cfae309a0ea7bbbc04ea785e8
Reviewed-on: https://boringssl-review.googlesource.com/7270
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-02 15:57:27 +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