Later CLs will clean up the ClientHello construction a bit (draft-12
avoids computing ClientHelloOuter twice). I suspect the transcript
handling on the client can also be simpler, but I'll see what's
convenient after I've changed how ClientHelloOuter is constructed.
Changes of note between draft-10 and draft-13:
- There is now an ECH confirmation signal in both HRR and SH. We don't
actually make much use of this in our client right now, but it
resolves a bunch of weird issues around HRR, including edge cases if
HRR applies to one ClientHello but not the other.
- The confirmation signal no longer depends on key_share and PSK, so we
don't have to work around a weird ordering issue.
- ech_is_inner is now folded into the main encrypted_client_hello code
point. This works better with some stuff around HRR.
- Padding is moved from the padding extension, computed with
ClientHelloInner, to something we fill in afterwards. This makes it
easier to pad up the whole thing to a multiple of 32. I've accordingly
updated to the latest recommended padding construction, and updated
the GREASE logic to match.
- ech_outer_extensions is much easier to process because the order is
required to be consistent. We were doing that anyway, and now a simple
linear scan works.
- ClientHelloOuterAAD now uses an all zero placeholder payload of the
same length. This lets us simplify the server code, but, for now, I've
kept the client code the same. I'll follow this up with a CL to avoid
computing ClientHelloOuter twice.
- ClientHelloOuterAAD is allowed to contain a placeholder PSK. I haven't
filled that in and will do it in a follow-up CL.
Bug: 275
Change-Id: I7464345125c53968b2fe692f9268e392120fc2eb
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/48912
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Also avoid unnecessarily stashing a copy of the serialized old
ClientHello.
Change-Id: I699299f0ce767ba059fbb08e8f2140793a649322
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46628
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
All the comments say the buffer is only needed in TLS 1.2, but this
doesn't match the code. The code uses the buffer in one place, for ECH,
to avoid copying a hash.Hash. Go does support this, albeit in a *very*
roundabout way.
This is ugly but means we can now properly drop the handshake buffer in
TLS 1.3.
Change-Id: I4a1559a64fcb98ccfbab54de99402fe6f62725a1
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46627
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
The 'client' and 'server' halves are remnants of SSL 3.0 and Go
(originally) lacking a way to clone hash.Hash. The Go limitation meant
that computing SSL 3.0's proto-HMAC construction mutated the running
hash on Finished, so crypto/tls just maintained two of them.
Without SSL 3.0, this is no longer needed. That, however, leaves us with
having both a crypto.Hash and a hash.Hash, and both can't be named
'hash'. I stepped around this by storing the cipher suite itself and
using cipherSuite.hash().
Change-Id: Ia38880ae446949baa2181d33136c748cf5374664
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46626
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
We only need to implement enough of SSL 3.0 to test that the shim does
not.
Change-Id: I25cb48e407f1bc458bbdb3544b9df9fdfbc3d9c9
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46625
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
This avoids duplicating some code in client and server. It should also
clean up some ECH test code, which needs to juggle a pair of transcripts
for a brief window.
Change-Id: I4db11119e34b56453f01b5890060b8d4129a25b9
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46564
Reviewed-by: Adam Langley <agl@google.com>
This CL implements the backend server behavior described in Section 7.2
of draft-ietf-tls-esni-09.
Bug: 275
Change-Id: I2e162673ce564db0cb75fc9b71ef11ed15037f4b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43924
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
The CI should be set up to retain the Go module and build caches, so
we'll avoid downloading it multiple times. This avoids having to
replicate some code.
Update-Note: The tests now have a golang.org/x/crypto dependency. This
should be fetched transparently with Go modules. Monorepos with
different import path conventions may need to rewrite these imports.
Change-Id: If5ba52e051f180536d72109c2e690bbd13d58e7c
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42044
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
David Benjamin
Dan McArdle
Adam Langley