code review 130950043: go.crypto/sha3: update to sync with draft FIPS-202

sha3/keccakf.go

-// Copyright 2013 The Go Authors. All rights reserved.
+// Copyright 2014 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package sha3
 
-// This file implements the core Keccak permutation function necessary for computing SHA3.
-// This is implemented in a separate file to allow for replacement by an optimized implementation.
-// Nothing in this package is exported.
-// For the detailed specification, refer to the Keccak web site (http://keccak.noekeon.org/).
-
 // rc stores the round constants for use in the ι step.
-var rc = [...]uint64{
+var rc = [24]uint64{
         0x0000000000000001,
         0x0000000000008082,
         0x800000000000808A,
         0x8000000080008000,
         0x000000000000808B,
         0x0000000080000001,
         0x8000000080008081,
         0x8000000000008009,
         0x000000000000008A,
         0x0000000000000088,
         0x0000000080008009,
         0x000000008000000A,
         0x000000008000808B,
         0x800000000000008B,
         0x8000000000008089,
         0x8000000000008003,
         0x8000000000008002,
         0x8000000000000080,
         0x000000000000800A,
         0x800000008000000A,
         0x8000000080008081,
         0x8000000000008080,
         0x0000000080000001,
         0x8000000080008008,
 }
 
-// keccakF computes the complete Keccak-f function consisting of 24 rounds with a different
-// constant (rc) in each round. This implementation fully unrolls the round function to avoid
-// inner loops, as well as pre-calculating shift offsets.
-func keccakF(a *[numLanes]uint64) {
+// KeccakF1600 applies the Keccak permutation to a 1600b-wide
+// state represented as a slice of 25 uint64s.
+func KeccakF1600(a *[25]uint64) {
         var t, bc0, bc1, bc2, bc3, bc4 uint64
         for _, roundConstant := range rc {
                 // θ step
                 bc0 = a[0] ^ a[5] ^ a[10] ^ a[15] ^ a[20]
                 bc1 = a[1] ^ a[6] ^ a[11] ^ a[16] ^ a[21]
                 bc2 = a[2] ^ a[7] ^ a[12] ^ a[17] ^ a[22]
                 bc3 = a[3] ^ a[8] ^ a[13] ^ a[18] ^ a[23]
                 bc4 = a[4] ^ a[9] ^ a[14] ^ a[19] ^ a[24]
                 t = bc4 ^ (bc1<<1 ^ bc1>>63)
                 a[0] ^= t
@@ skipping 102 matching lines @@
                 a[20] ^= bc2 &^ bc1
                 a[21] ^= bc3 &^ bc2
                 a[22] ^= bc4 &^ bc3
                 a[23] ^= bc0 &^ bc4
                 a[24] ^= bc1 &^ bc0
 
                 // ι step
                 a[0] ^= roundConstant
         }
 }