Commit Graph

3 Commits

Author SHA1 Message Date
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