go.crypto/salsa20: add salsa.Core208.

R=golang-dev, agl, r
CC=golang-dev
https://golang.org/cl/6530044

salsa20/salsa/salsa208.go

@@ -0,0 +1,199 @@
+// Copyright 2012 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 salsa
+
+// Core208 applies the Salsa20/8 core function to the 64-byte array in and puts
+// the result into the 64-byte array out. The input and output may be the same array.
+func Core208(out *[64]byte, in *[64]byte) {
+	j0 := uint32(in[0]) | uint32(in[1])<<8 | uint32(in[2])<<16 | uint32(in[3])<<24
+	j1 := uint32(in[4]) | uint32(in[5])<<8 | uint32(in[6])<<16 | uint32(in[7])<<24
+	j2 := uint32(in[8]) | uint32(in[9])<<8 | uint32(in[10])<<16 | uint32(in[11])<<24
+	j3 := uint32(in[12]) | uint32(in[13])<<8 | uint32(in[14])<<16 | uint32(in[15])<<24
+	j4 := uint32(in[16]) | uint32(in[17])<<8 | uint32(in[18])<<16 | uint32(in[19])<<24
+	j5 := uint32(in[20]) | uint32(in[21])<<8 | uint32(in[22])<<16 | uint32(in[23])<<24
+	j6 := uint32(in[24]) | uint32(in[25])<<8 | uint32(in[26])<<16 | uint32(in[27])<<24
+	j7 := uint32(in[28]) | uint32(in[29])<<8 | uint32(in[30])<<16 | uint32(in[31])<<24
+	j8 := uint32(in[32]) | uint32(in[33])<<8 | uint32(in[34])<<16 | uint32(in[35])<<24
+	j9 := uint32(in[36]) | uint32(in[37])<<8 | uint32(in[38])<<16 | uint32(in[39])<<24
+	j10 := uint32(in[40]) | uint32(in[41])<<8 | uint32(in[42])<<16 | uint32(in[43])<<24
+	j11 := uint32(in[44]) | uint32(in[45])<<8 | uint32(in[46])<<16 | uint32(in[47])<<24
+	j12 := uint32(in[48]) | uint32(in[49])<<8 | uint32(in[50])<<16 | uint32(in[51])<<24
+	j13 := uint32(in[52]) | uint32(in[53])<<8 | uint32(in[54])<<16 | uint32(in[55])<<24
+	j14 := uint32(in[56]) | uint32(in[57])<<8 | uint32(in[58])<<16 | uint32(in[59])<<24
+	j15 := uint32(in[60]) | uint32(in[61])<<8 | uint32(in[62])<<16 | uint32(in[63])<<24
+
+	x0, x1, x2, x3, x4, x5, x6, x7, x8 := j0, j1, j2, j3, j4, j5, j6, j7, j8
+	x9, x10, x11, x12, x13, x14, x15 := j9, j10, j11, j12, j13, j14, j15
+
+	for i := 0; i < 8; i += 2 {
+		u := x0 + x12
+		x4 ^= u<<7 | u>>(32-7)
+		u = x4 + x0
+		x8 ^= u<<9 | u>>(32-9)
+		u = x8 + x4
+		x12 ^= u<<13 | u>>(32-13)
+		u = x12 + x8
+		x0 ^= u<<18 | u>>(32-18)
+
+		u = x5 + x1
+		x9 ^= u<<7 | u>>(32-7)
+		u = x9 + x5
+		x13 ^= u<<9 | u>>(32-9)
+		u = x13 + x9
+		x1 ^= u<<13 | u>>(32-13)
+		u = x1 + x13
+		x5 ^= u<<18 | u>>(32-18)
+
+		u = x10 + x6
+		x14 ^= u<<7 | u>>(32-7)
+		u = x14 + x10
+		x2 ^= u<<9 | u>>(32-9)
+		u = x2 + x14
+		x6 ^= u<<13 | u>>(32-13)
+		u = x6 + x2
+		x10 ^= u<<18 | u>>(32-18)
+
+		u = x15 + x11
+		x3 ^= u<<7 | u>>(32-7)
+		u = x3 + x15
+		x7 ^= u<<9 | u>>(32-9)
+		u = x7 + x3
+		x11 ^= u<<13 | u>>(32-13)
+		u = x11 + x7
+		x15 ^= u<<18 | u>>(32-18)
+
+		u = x0 + x3
+		x1 ^= u<<7 | u>>(32-7)
+		u = x1 + x0
+		x2 ^= u<<9 | u>>(32-9)
+		u = x2 + x1
+		x3 ^= u<<13 | u>>(32-13)
+		u = x3 + x2
+		x0 ^= u<<18 | u>>(32-18)
+
+		u = x5 + x4
+		x6 ^= u<<7 | u>>(32-7)
+		u = x6 + x5
+		x7 ^= u<<9 | u>>(32-9)
+		u = x7 + x6
+		x4 ^= u<<13 | u>>(32-13)
+		u = x4 + x7
+		x5 ^= u<<18 | u>>(32-18)
+
+		u = x10 + x9
+		x11 ^= u<<7 | u>>(32-7)
+		u = x11 + x10
+		x8 ^= u<<9 | u>>(32-9)
+		u = x8 + x11
+		x9 ^= u<<13 | u>>(32-13)
+		u = x9 + x8
+		x10 ^= u<<18 | u>>(32-18)
+
+		u = x15 + x14
+		x12 ^= u<<7 | u>>(32-7)
+		u = x12 + x15
+		x13 ^= u<<9 | u>>(32-9)
+		u = x13 + x12
+		x14 ^= u<<13 | u>>(32-13)
+		u = x14 + x13
+		x15 ^= u<<18 | u>>(32-18)
+	}
+	x0 += j0
+	x1 += j1
+	x2 += j2
+	x3 += j3
+	x4 += j4
+	x5 += j5
+	x6 += j6
+	x7 += j7
+	x8 += j8
+	x9 += j9
+	x10 += j10
+	x11 += j11
+	x12 += j12
+	x13 += j13
+	x14 += j14
+	x15 += j15
+
+	out[0] = byte(x0)
+	out[1] = byte(x0 >> 8)
+	out[2] = byte(x0 >> 16)
+	out[3] = byte(x0 >> 24)
+
+	out[4] = byte(x1)
+	out[5] = byte(x1 >> 8)
+	out[6] = byte(x1 >> 16)
+	out[7] = byte(x1 >> 24)
+
+	out[8] = byte(x2)
+	out[9] = byte(x2 >> 8)
+	out[10] = byte(x2 >> 16)
+	out[11] = byte(x2 >> 24)
+
+	out[12] = byte(x3)
+	out[13] = byte(x3 >> 8)
+	out[14] = byte(x3 >> 16)
+	out[15] = byte(x3 >> 24)
+
+	out[16] = byte(x4)
+	out[17] = byte(x4 >> 8)
+	out[18] = byte(x4 >> 16)
+	out[19] = byte(x4 >> 24)
+
+	out[20] = byte(x5)
+	out[21] = byte(x5 >> 8)
+	out[22] = byte(x5 >> 16)
+	out[23] = byte(x5 >> 24)
+
+	out[24] = byte(x6)
+	out[25] = byte(x6 >> 8)
+	out[26] = byte(x6 >> 16)
+	out[27] = byte(x6 >> 24)
+
+	out[28] = byte(x7)
+	out[29] = byte(x7 >> 8)
+	out[30] = byte(x7 >> 16)
+	out[31] = byte(x7 >> 24)
+
+	out[32] = byte(x8)
+	out[33] = byte(x8 >> 8)
+	out[34] = byte(x8 >> 16)
+	out[35] = byte(x8 >> 24)
+
+	out[36] = byte(x9)
+	out[37] = byte(x9 >> 8)
+	out[38] = byte(x9 >> 16)
+	out[39] = byte(x9 >> 24)
+
+	out[40] = byte(x10)
+	out[41] = byte(x10 >> 8)
+	out[42] = byte(x10 >> 16)
+	out[43] = byte(x10 >> 24)
+
+	out[44] = byte(x11)
+	out[45] = byte(x11 >> 8)
+	out[46] = byte(x11 >> 16)
+	out[47] = byte(x11 >> 24)
+
+	out[48] = byte(x12)
+	out[49] = byte(x12 >> 8)
+	out[50] = byte(x12 >> 16)
+	out[51] = byte(x12 >> 24)
+
+	out[52] = byte(x13)
+	out[53] = byte(x13 >> 8)
+	out[54] = byte(x13 >> 16)
+	out[55] = byte(x13 >> 24)
+
+	out[56] = byte(x14)
+	out[57] = byte(x14 >> 8)
+	out[58] = byte(x14 >> 16)
+	out[59] = byte(x14 >> 24)
+
+	out[60] = byte(x15)
+	out[61] = byte(x15 >> 8)
+	out[62] = byte(x15 >> 16)
+	out[63] = byte(x15 >> 24)
+}

salsa20/salsa/salsa_test.go

@@ -0,0 +1,35 @@
+// Copyright 2012 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 salsa
+
+import "testing"
+
+func TestCore208(t *testing.T) {
+	in := [64]byte{
+		0x7e, 0x87, 0x9a, 0x21, 0x4f, 0x3e, 0xc9, 0x86,
+		0x7c, 0xa9, 0x40, 0xe6, 0x41, 0x71, 0x8f, 0x26,
+		0xba, 0xee, 0x55, 0x5b, 0x8c, 0x61, 0xc1, 0xb5,
+		0x0d, 0xf8, 0x46, 0x11, 0x6d, 0xcd, 0x3b, 0x1d,
+		0xee, 0x24, 0xf3, 0x19, 0xdf, 0x9b, 0x3d, 0x85,
+		0x14, 0x12, 0x1e, 0x4b, 0x5a, 0xc5, 0xaa, 0x32,
+		0x76, 0x02, 0x1d, 0x29, 0x09, 0xc7, 0x48, 0x29,
+		0xed, 0xeb, 0xc6, 0x8d, 0xb8, 0xb8, 0xc2, 0x5e}
+
+	out := [64]byte{
+		0xa4, 0x1f, 0x85, 0x9c, 0x66, 0x08, 0xcc, 0x99,
+		0x3b, 0x81, 0xca, 0xcb, 0x02, 0x0c, 0xef, 0x05,
+		0x04, 0x4b, 0x21, 0x81, 0xa2, 0xfd, 0x33, 0x7d,
+		0xfd, 0x7b, 0x1c, 0x63, 0x96, 0x68, 0x2f, 0x29,
+		0xb4, 0x39, 0x31, 0x68, 0xe3, 0xc9, 0xe6, 0xbc,
+		0xfe, 0x6b, 0xc5, 0xb7, 0xa0, 0x6d, 0x96, 0xba,
+		0xe4, 0x24, 0xcc, 0x10, 0x2c, 0x91, 0x74, 0x5c,
+		0x24, 0xad, 0x67, 0x3d, 0xc7, 0x61, 0x8f, 0x81,
+	}
+
+	Core208(&in, &in)
+	if in != out {
+		t.Errorf("expected %x, got %x", out, in)
+	}
+}