Commit Graph

8 Commits

Author SHA1 Message Date
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
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
Piotr Sikora
9bb8ba6ba1 Make local functions static.
Partially fixes build with -Wmissing-prototypes -Wmissing-declarations.

Change-Id: I6048f5b7ef31560399b25ed9880156bc7d8abac2
Signed-off-by: Piotr Sikora <piotrsikora@google.com>
Reviewed-on: https://boringssl-review.googlesource.com/7511
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-20 16:37:58 +00:00
David Benjamin
ad004af661 Rename NID_x25519 to NID_X25519.
I went with NID_x25519 to match NID_sha1 and friends in being lowercase.
However, upstream seems to have since chosen NID_X25519. Match their
name.

Change-Id: Icc7b183a2e2dfbe42c88e08e538fcbd242478ac3
Reviewed-on: https://boringssl-review.googlesource.com/7331
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-03-07 15:48:51 +00:00
David Benjamin
6014ea6248 Add EC_POINT_point2cbb.
This slightly simplifies the SSL_ECDH code and will be useful later on
in reimplementing the key parsing logic.

Change-Id: Ie41ea5fd3a9a734b3879b715fbf57bd991e23799
Reviewed-on: https://boringssl-review.googlesource.com/6858
Reviewed-by: Adam Langley <agl@google.com>
2016-02-02 19:04:33 +00:00
David Benjamin
fc6e5a7372 Drop the silly 'ECDH_' prefix on X25519.
I got that from the TLS 1.3 draft, but it's kind of silly-looking. X25519
already refers to a Diffie-Hellman primitive.

Also hopefully the WG will split NamedGroups and SignatureAlgorithms per the
recent proposal, so it won't be needed anyway. (Most chatter is about what
hashes should be allowed with what NIST curves, so it seems like people like
the split itself? We'll see.)

Change-Id: I7bb713190001199a3ebd30b67df2c00d29132431
Reviewed-on: https://boringssl-review.googlesource.com/6912
Reviewed-by: Adam Langley <agl@google.com>
2016-01-20 17:26:13 +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