Pull in code for BLAKE2b hash function

compression/f.go

@@ -0,0 +1,180 @@
+// Copyright 2016 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.
+//
+// Modified by KEEP SEZC to expose F compression function.
+//
+package compression
+
+import (
+	"math/bits"
+)
+
+// IV is an initialization vector for BLAKE2b
+var IV = [8]uint64{
+	0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
+	0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179,
+}
+
+// the precomputed values for BLAKE2b
+// there are 10 16-byte arrays - one for each round
+// the entries are calculated from the sigma constants.
+var precomputed = [10][16]byte{
+	{0, 2, 4, 6, 1, 3, 5, 7, 8, 10, 12, 14, 9, 11, 13, 15},
+	{14, 4, 9, 13, 10, 8, 15, 6, 1, 0, 11, 5, 12, 2, 7, 3},
+	{11, 12, 5, 15, 8, 0, 2, 13, 10, 3, 7, 9, 14, 6, 1, 4},
+	{7, 3, 13, 11, 9, 1, 12, 14, 2, 5, 4, 15, 6, 10, 0, 8},
+	{9, 5, 2, 10, 0, 7, 4, 15, 14, 11, 6, 3, 1, 12, 8, 13},
+	{2, 6, 0, 8, 12, 10, 11, 3, 4, 7, 15, 1, 13, 5, 14, 9},
+	{12, 1, 14, 4, 5, 15, 13, 10, 0, 6, 9, 8, 7, 3, 2, 11},
+	{13, 7, 12, 3, 11, 14, 1, 9, 5, 15, 8, 2, 0, 4, 6, 10},
+	{6, 14, 11, 0, 15, 9, 3, 8, 12, 13, 1, 10, 2, 7, 4, 5},
+	{10, 8, 7, 1, 2, 4, 6, 5, 15, 9, 3, 13, 11, 14, 12, 0},
+}
+
+// F is a compression function for BLAKE2b. It takes as an argument the state
+// vector `h`, message block vector `m`, offset counter `t`, final
+// block indicator flag `f`, and number of rounds `rounds`. The state vector
+// provided as the first parameter is modified by the function.
+func F(h *[8]uint64, m [16]uint64, c [2]uint64, f bool, rounds uint32) {
+	c0, c1 := c[0], c[1]
+
+	v0, v1, v2, v3, v4, v5, v6, v7 := h[0], h[1], h[2], h[3], h[4], h[5], h[6], h[7]
+	v8, v9, v10, v11, v12, v13, v14, v15 := IV[0], IV[1], IV[2], IV[3], IV[4], IV[5], IV[6], IV[7]
+	v12 ^= c0
+	v13 ^= c1
+
+	if f {
+		v14 ^= 0xffffffffffffffff
+	}
+
+	for j := uint32(0); j < rounds; j++ {
+		s := &(precomputed[j%10])
+
+		v0 += m[s[0]]
+		v0 += v4
+		v12 ^= v0
+		v12 = bits.RotateLeft64(v12, -32)
+		v8 += v12
+		v4 ^= v8
+		v4 = bits.RotateLeft64(v4, -24)
+		v1 += m[s[1]]
+		v1 += v5
+		v13 ^= v1
+		v13 = bits.RotateLeft64(v13, -32)
+		v9 += v13
+		v5 ^= v9
+		v5 = bits.RotateLeft64(v5, -24)
+		v2 += m[s[2]]
+		v2 += v6
+		v14 ^= v2
+		v14 = bits.RotateLeft64(v14, -32)
+		v10 += v14
+		v6 ^= v10
+		v6 = bits.RotateLeft64(v6, -24)
+		v3 += m[s[3]]
+		v3 += v7
+		v15 ^= v3
+		v15 = bits.RotateLeft64(v15, -32)
+		v11 += v15
+		v7 ^= v11
+		v7 = bits.RotateLeft64(v7, -24)
+
+		v0 += m[s[4]]
+		v0 += v4
+		v12 ^= v0
+		v12 = bits.RotateLeft64(v12, -16)
+		v8 += v12
+		v4 ^= v8
+		v4 = bits.RotateLeft64(v4, -63)
+		v1 += m[s[5]]
+		v1 += v5
+		v13 ^= v1
+		v13 = bits.RotateLeft64(v13, -16)
+		v9 += v13
+		v5 ^= v9
+		v5 = bits.RotateLeft64(v5, -63)
+		v2 += m[s[6]]
+		v2 += v6
+		v14 ^= v2
+		v14 = bits.RotateLeft64(v14, -16)
+		v10 += v14
+		v6 ^= v10
+		v6 = bits.RotateLeft64(v6, -63)
+		v3 += m[s[7]]
+		v3 += v7
+		v15 ^= v3
+		v15 = bits.RotateLeft64(v15, -16)
+		v11 += v15
+		v7 ^= v11
+		v7 = bits.RotateLeft64(v7, -63)
+
+		v0 += m[s[8]]
+		v0 += v5
+		v15 ^= v0
+		v15 = bits.RotateLeft64(v15, -32)
+		v10 += v15
+		v5 ^= v10
+		v5 = bits.RotateLeft64(v5, -24)
+		v1 += m[s[9]]
+		v1 += v6
+		v12 ^= v1
+		v12 = bits.RotateLeft64(v12, -32)
+		v11 += v12
+		v6 ^= v11
+		v6 = bits.RotateLeft64(v6, -24)
+		v2 += m[s[10]]
+		v2 += v7
+		v13 ^= v2
+		v13 = bits.RotateLeft64(v13, -32)
+		v8 += v13
+		v7 ^= v8
+		v7 = bits.RotateLeft64(v7, -24)
+		v3 += m[s[11]]
+		v3 += v4
+		v14 ^= v3
+		v14 = bits.RotateLeft64(v14, -32)
+		v9 += v14
+		v4 ^= v9
+		v4 = bits.RotateLeft64(v4, -24)
+
+		v0 += m[s[12]]
+		v0 += v5
+		v15 ^= v0
+		v15 = bits.RotateLeft64(v15, -16)
+		v10 += v15
+		v5 ^= v10
+		v5 = bits.RotateLeft64(v5, -63)
+		v1 += m[s[13]]
+		v1 += v6
+		v12 ^= v1
+		v12 = bits.RotateLeft64(v12, -16)
+		v11 += v12
+		v6 ^= v11
+		v6 = bits.RotateLeft64(v6, -63)
+		v2 += m[s[14]]
+		v2 += v7
+		v13 ^= v2
+		v13 = bits.RotateLeft64(v13, -16)
+		v8 += v13
+		v7 ^= v8
+		v7 = bits.RotateLeft64(v7, -63)
+		v3 += m[s[15]]
+		v3 += v4
+		v14 ^= v3
+		v14 = bits.RotateLeft64(v14, -16)
+		v9 += v14
+		v4 ^= v9
+		v4 = bits.RotateLeft64(v4, -63)
+
+	}
+
+	h[0] ^= v0 ^ v8
+	h[1] ^= v1 ^ v9
+	h[2] ^= v2 ^ v10
+	h[3] ^= v3 ^ v11
+	h[4] ^= v4 ^ v12
+	h[5] ^= v5 ^ v13
+	h[6] ^= v6 ^ v14
+	h[7] ^= v7 ^ v15
+}