|
|
// 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 provides low-level access to functions in the Salsa family.
package salsa // import "golang.org/x/crypto/salsa20/salsa"
// Sigma is the Salsa20 constant for 256-bit keys.
var Sigma = [16]byte{'e', 'x', 'p', 'a', 'n', 'd', ' ', '3', '2', '-', 'b', 'y', 't', 'e', ' ', 'k'}
// HSalsa20 applies the HSalsa20 core function to a 16-byte input in, 32-byte
// key k, and 16-byte constant c, and puts the result into the 32-byte array
// out.
func HSalsa20(out *[32]byte, in *[16]byte, k *[32]byte, c *[16]byte) { x0 := uint32(c[0]) | uint32(c[1])<<8 | uint32(c[2])<<16 | uint32(c[3])<<24 x1 := uint32(k[0]) | uint32(k[1])<<8 | uint32(k[2])<<16 | uint32(k[3])<<24 x2 := uint32(k[4]) | uint32(k[5])<<8 | uint32(k[6])<<16 | uint32(k[7])<<24 x3 := uint32(k[8]) | uint32(k[9])<<8 | uint32(k[10])<<16 | uint32(k[11])<<24 x4 := uint32(k[12]) | uint32(k[13])<<8 | uint32(k[14])<<16 | uint32(k[15])<<24 x5 := uint32(c[4]) | uint32(c[5])<<8 | uint32(c[6])<<16 | uint32(c[7])<<24 x6 := uint32(in[0]) | uint32(in[1])<<8 | uint32(in[2])<<16 | uint32(in[3])<<24 x7 := uint32(in[4]) | uint32(in[5])<<8 | uint32(in[6])<<16 | uint32(in[7])<<24 x8 := uint32(in[8]) | uint32(in[9])<<8 | uint32(in[10])<<16 | uint32(in[11])<<24 x9 := uint32(in[12]) | uint32(in[13])<<8 | uint32(in[14])<<16 | uint32(in[15])<<24 x10 := uint32(c[8]) | uint32(c[9])<<8 | uint32(c[10])<<16 | uint32(c[11])<<24 x11 := uint32(k[16]) | uint32(k[17])<<8 | uint32(k[18])<<16 | uint32(k[19])<<24 x12 := uint32(k[20]) | uint32(k[21])<<8 | uint32(k[22])<<16 | uint32(k[23])<<24 x13 := uint32(k[24]) | uint32(k[25])<<8 | uint32(k[26])<<16 | uint32(k[27])<<24 x14 := uint32(k[28]) | uint32(k[29])<<8 | uint32(k[30])<<16 | uint32(k[31])<<24 x15 := uint32(c[12]) | uint32(c[13])<<8 | uint32(c[14])<<16 | uint32(c[15])<<24
for i := 0; i < 20; 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) } out[0] = byte(x0) out[1] = byte(x0 >> 8) out[2] = byte(x0 >> 16) out[3] = byte(x0 >> 24)
out[4] = byte(x5) out[5] = byte(x5 >> 8) out[6] = byte(x5 >> 16) out[7] = byte(x5 >> 24)
out[8] = byte(x10) out[9] = byte(x10 >> 8) out[10] = byte(x10 >> 16) out[11] = byte(x10 >> 24)
out[12] = byte(x15) out[13] = byte(x15 >> 8) out[14] = byte(x15 >> 16) out[15] = byte(x15 >> 24)
out[16] = byte(x6) out[17] = byte(x6 >> 8) out[18] = byte(x6 >> 16) out[19] = byte(x6 >> 24)
out[20] = byte(x7) out[21] = byte(x7 >> 8) out[22] = byte(x7 >> 16) out[23] = byte(x7 >> 24)
out[24] = byte(x8) out[25] = byte(x8 >> 8) out[26] = byte(x8 >> 16) out[27] = byte(x8 >> 24)
out[28] = byte(x9) out[29] = byte(x9 >> 8) out[30] = byte(x9 >> 16) out[31] = byte(x9 >> 24)}
|
