143 lines
4.5 KiB
Go
143 lines
4.5 KiB
Go
// Copyright 2010 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package des implements the Data Encryption Standard (DES) and the
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// Triple Data Encryption Algorithm (TDEA) as defined
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// in U.S. Federal Information Processing Standards Publication 46-3.
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//
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// DES is cryptographically broken and should not be used for secure
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// applications.
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package des
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// Used to perform an initial permutation of a 64-bit input block.
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var initialPermutation = [64]byte{
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6, 14, 22, 30, 38, 46, 54, 62,
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4, 12, 20, 28, 36, 44, 52, 60,
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2, 10, 18, 26, 34, 42, 50, 58,
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0, 8, 16, 24, 32, 40, 48, 56,
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7, 15, 23, 31, 39, 47, 55, 63,
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5, 13, 21, 29, 37, 45, 53, 61,
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3, 11, 19, 27, 35, 43, 51, 59,
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1, 9, 17, 25, 33, 41, 49, 57,
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}
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// Used to perform a final permutation of a 4-bit preoutput block. This is the
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// inverse of initialPermutation
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var finalPermutation = [64]byte{
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24, 56, 16, 48, 8, 40, 0, 32,
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25, 57, 17, 49, 9, 41, 1, 33,
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26, 58, 18, 50, 10, 42, 2, 34,
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27, 59, 19, 51, 11, 43, 3, 35,
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28, 60, 20, 52, 12, 44, 4, 36,
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29, 61, 21, 53, 13, 45, 5, 37,
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30, 62, 22, 54, 14, 46, 6, 38,
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31, 63, 23, 55, 15, 47, 7, 39,
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}
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// Used to expand an input block of 32 bits, producing an output block of 48
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// bits.
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var expansionFunction = [48]byte{
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0, 31, 30, 29, 28, 27, 28, 27,
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26, 25, 24, 23, 24, 23, 22, 21,
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20, 19, 20, 19, 18, 17, 16, 15,
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16, 15, 14, 13, 12, 11, 12, 11,
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10, 9, 8, 7, 8, 7, 6, 5,
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4, 3, 4, 3, 2, 1, 0, 31,
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}
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// Yields a 32-bit output from a 32-bit input
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var permutationFunction = [32]byte{
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16, 25, 12, 11, 3, 20, 4, 15,
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31, 17, 9, 6, 27, 14, 1, 22,
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30, 24, 8, 18, 0, 5, 29, 23,
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13, 19, 2, 26, 10, 21, 28, 7,
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}
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// Used in the key schedule to select 56 bits
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// from a 64-bit input.
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var permutedChoice1 = [56]byte{
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7, 15, 23, 31, 39, 47, 55, 63,
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6, 14, 22, 30, 38, 46, 54, 62,
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5, 13, 21, 29, 37, 45, 53, 61,
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4, 12, 20, 28, 1, 9, 17, 25,
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33, 41, 49, 57, 2, 10, 18, 26,
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34, 42, 50, 58, 3, 11, 19, 27,
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35, 43, 51, 59, 36, 44, 52, 60,
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}
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// Used in the key schedule to produce each subkey by selecting 48 bits from
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// the 56-bit input
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var permutedChoice2 = [48]byte{
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42, 39, 45, 32, 55, 51, 53, 28,
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41, 50, 35, 46, 33, 37, 44, 52,
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30, 48, 40, 49, 29, 36, 43, 54,
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15, 4, 25, 19, 9, 1, 26, 16,
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5, 11, 23, 8, 12, 7, 17, 0,
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22, 3, 10, 14, 6, 20, 27, 24,
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}
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// 8 S-boxes composed of 4 rows and 16 columns
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// Used in the DES cipher function
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var sBoxes = [8][4][16]uint8{
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// S-box 1
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{
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{14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7},
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{0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8},
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{4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0},
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{15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13},
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},
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// S-box 2
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{
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{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},
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{3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5},
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{0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15},
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{13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9},
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},
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// S-box 3
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{
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{10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8},
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{13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1},
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{13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7},
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{1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12},
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},
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// S-box 4
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{
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{7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15},
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{13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9},
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{10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4},
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{3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14},
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},
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// S-box 5
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{
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{2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9},
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{14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6},
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{4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14},
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{11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3},
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},
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// S-box 6
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{
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{12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11},
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{10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8},
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{9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6},
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{4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13},
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},
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// S-box 7
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{
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{4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1},
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{13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6},
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{1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2},
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{6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12},
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},
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// S-box 8
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{
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{13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7},
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{1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2},
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{7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8},
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{2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11},
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},
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}
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// Size of left rotation per round in each half of the key schedule
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var ksRotations = [16]uint8{1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1}
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