crypto/tls: len(clientRandom) used for serverRandom source

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>
This commit is contained in:
Ralph Corderoy 2015-11-07 11:45:00 +00:00 committed by Adam Langley
parent f75fa96c2c
commit 59e7c9bc39

17
prf.go
View File

@ -145,11 +145,12 @@ func prfForVersion(version uint16, suite *cipherSuite) func(result, secret, labe
// masterFromPreMasterSecret generates the master secret from the pre-master
// secret. See http://tools.ietf.org/html/rfc5246#section-8.1
func masterFromPreMasterSecret(version uint16, suite *cipherSuite, preMasterSecret, clientRandom, serverRandom []byte) []byte {
var seed [tlsRandomLength * 2]byte
copy(seed[0:len(clientRandom)], clientRandom)
copy(seed[len(clientRandom):], serverRandom)
seed := make([]byte, 0, len(clientRandom)+len(serverRandom))
seed = append(seed, clientRandom...)
seed = append(seed, serverRandom...)
masterSecret := make([]byte, masterSecretLength)
prfForVersion(version, suite)(masterSecret, preMasterSecret, masterSecretLabel, seed[0:])
prfForVersion(version, suite)(masterSecret, preMasterSecret, masterSecretLabel, seed)
return masterSecret
}
@ -157,13 +158,13 @@ func masterFromPreMasterSecret(version uint16, suite *cipherSuite, preMasterSecr
// secret, given the lengths of the MAC key, cipher key and IV, as defined in
// RFC 2246, section 6.3.
func keysFromMasterSecret(version uint16, suite *cipherSuite, masterSecret, clientRandom, serverRandom []byte, macLen, keyLen, ivLen int) (clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV []byte) {
var seed [tlsRandomLength * 2]byte
copy(seed[0:len(clientRandom)], serverRandom)
copy(seed[len(serverRandom):], clientRandom)
seed := make([]byte, 0, len(serverRandom)+len(clientRandom))
seed = append(seed, serverRandom...)
seed = append(seed, clientRandom...)
n := 2*macLen + 2*keyLen + 2*ivLen
keyMaterial := make([]byte, n)
prfForVersion(version, suite)(keyMaterial, masterSecret, keyExpansionLabel, seed[0:])
prfForVersion(version, suite)(keyMaterial, masterSecret, keyExpansionLabel, seed)
clientMAC = keyMaterial[:macLen]
keyMaterial = keyMaterial[macLen:]
serverMAC = keyMaterial[:macLen]