In keysFromMasterSecret(), don't copy from serverRandom into
seed[:len(clientRandom)]. Actually, switch from an array to a slice in
keysFromMasterSecret() and masterFromPreMasterSecret() so the length
need not be given; that's how it's done elsewhere in the file.
Fixes#13181
Change-Id: I92abaa892d1bba80c2d4f12776341cda7d538837
Reviewed-on: https://go-review.googlesource.com/16697
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Prior to TLS 1.2, the handshake had a pleasing property that one could
incrementally hash it and, from that, get the needed hashes for both
the CertificateVerify and Finished messages.
TLS 1.2 introduced negotiation for the signature and hash and it became
possible for the handshake hash to be, say, SHA-384, but for the
CertificateVerify to sign the handshake with SHA-1. The problem is that
one doesn't know in advance which hashes will be needed and thus the
handshake needs to be buffered.
Go ignored this, always kept a single handshake hash, and any signatures
over the handshake had to use that hash.
However, there are a set of servers that inspect the client's offered
signature hash functions and will abort the handshake if one of the
server's certificates is signed with a hash function outside of that
set. https://robertsspaceindustries.com/ is an example of such a server.
Clearly not a lot of thought happened when that server code was written,
but its out there and we have to deal with it.
This change decouples the handshake hash from the CertificateVerify
hash. This lays the groundwork for advertising support for SHA-384 but
doesn't actually make that change in the interests of reviewability.
Updating the advertised hash functions will cause changes in many of the
testdata/ files and some errors might get lost in the noise. This change
only needs to update four testdata/ files: one because a SHA-384-based
handshake is now being signed with SHA-256 and the others because the
TLS 1.2 CertificateRequest message now includes SHA-1.
This change also has the effect of adding support for
client-certificates in SSLv3 servers. However, SSLv3 is now disabled by
default so this should be moot.
It would be possible to avoid much of this change and just support
SHA-384 for the ServerKeyExchange as the SKX only signs over the nonces
and SKX params (a design mistake in TLS). However, that would leave Go
in the odd situation where it advertised support for SHA-384, but would
only use the handshake hash when signing client certificates. I fear
that'll just cause problems in the future.
Much of this code was written by davidben@ for the purposes of testing
BoringSSL.
Partly addresses #9757
Change-Id: I5137a472b6076812af387a5a69fc62c7373cd485
Reviewed-on: https://go-review.googlesource.com/9415
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>
Just so that we notice in the future if another hash function is added
without updating this utility function, make it panic when passed an
unknown handshake hash function. (Which should never happen.)
Change-Id: I60a6fc01669441523d8c44e8fbe7ed435e7f04c8
Reviewed-on: https://go-review.googlesource.com/7646
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Joël Stemmer <stemmertech@gmail.com>
Commit f1d669aee994b28e1afcfe974680565932d25b70 added support for
AES_256_GCM_SHA384 cipher suites as specified in RFC5289. However, it
did not take the arbitrary hash function into account in the TLS client
handshake when using client certificates.
The hashForClientCertificate method always returned SHA256 as its
hashing function, even if it actually used a different one to calculate
its digest. Setting up the connection would eventually fail with the
error "tls: failed to sign handshake with client certificate:
crypto/rsa: input must be hashed message".
Included is an additional test for this specific situation that uses the
SHA384 hash.
Fixes#9808
Change-Id: Iccbf4ab225633471ef897907c208ad31f92855a3
Reviewed-on: https://go-review.googlesource.com/7040
Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
Generalizes PRF calculation for TLS 1.2 to support arbitrary hashes (SHA-384 instead of SHA-256).
Testdata were all updated to correspond with the new cipher suites in the handshake.
Change-Id: I3d9fc48c19d1043899e38255a53c80dc952ee08f
Reviewed-on: https://go-review.googlesource.com/3265
Reviewed-by: Adam Langley <agl@golang.org>
