const.go

Documentation: crypto/des

		 1  // Copyright 2010 The Go Authors. All rights reserved.
		 2  // Use of this source code is governed by a BSD-style
		 3  // license that can be found in the LICENSE file.
		 4  
		 5  // Package des implements the Data Encryption Standard (DES) and the
		 6  // Triple Data Encryption Algorithm (TDEA) as defined
		 7  // in U.S. Federal Information Processing Standards Publication 46-3.
		 8  //
		 9  // DES is cryptographically broken and should not be used for secure
		10  // applications.
		11  package des
		12  
		13  // Used to perform an initial permutation of a 64-bit input block.
		14  var initialPermutation = [64]byte{
		15  	6, 14, 22, 30, 38, 46, 54, 62,
		16  	4, 12, 20, 28, 36, 44, 52, 60,
		17  	2, 10, 18, 26, 34, 42, 50, 58,
		18  	0, 8, 16, 24, 32, 40, 48, 56,
		19  	7, 15, 23, 31, 39, 47, 55, 63,
		20  	5, 13, 21, 29, 37, 45, 53, 61,
		21  	3, 11, 19, 27, 35, 43, 51, 59,
		22  	1, 9, 17, 25, 33, 41, 49, 57,
		23  }
		24  
		25  // Used to perform a final permutation of a 4-bit preoutput block. This is the
		26  // inverse of initialPermutation
		27  var finalPermutation = [64]byte{
		28  	24, 56, 16, 48, 8, 40, 0, 32,
		29  	25, 57, 17, 49, 9, 41, 1, 33,
		30  	26, 58, 18, 50, 10, 42, 2, 34,
		31  	27, 59, 19, 51, 11, 43, 3, 35,
		32  	28, 60, 20, 52, 12, 44, 4, 36,
		33  	29, 61, 21, 53, 13, 45, 5, 37,
		34  	30, 62, 22, 54, 14, 46, 6, 38,
		35  	31, 63, 23, 55, 15, 47, 7, 39,
		36  }
		37  
		38  // Used to expand an input block of 32 bits, producing an output block of 48
		39  // bits.
		40  var expansionFunction = [48]byte{
		41  	0, 31, 30, 29, 28, 27, 28, 27,
		42  	26, 25, 24, 23, 24, 23, 22, 21,
		43  	20, 19, 20, 19, 18, 17, 16, 15,
		44  	16, 15, 14, 13, 12, 11, 12, 11,
		45  	10, 9, 8, 7, 8, 7, 6, 5,
		46  	4, 3, 4, 3, 2, 1, 0, 31,
		47  }
		48  
		49  // Yields a 32-bit output from a 32-bit input
		50  var permutationFunction = [32]byte{
		51  	16, 25, 12, 11, 3, 20, 4, 15,
		52  	31, 17, 9, 6, 27, 14, 1, 22,
		53  	30, 24, 8, 18, 0, 5, 29, 23,
		54  	13, 19, 2, 26, 10, 21, 28, 7,
		55  }
		56  
		57  // Used in the key schedule to select 56 bits
		58  // from a 64-bit input.
		59  var permutedChoice1 = [56]byte{
		60  	7, 15, 23, 31, 39, 47, 55, 63,
		61  	6, 14, 22, 30, 38, 46, 54, 62,
		62  	5, 13, 21, 29, 37, 45, 53, 61,
		63  	4, 12, 20, 28, 1, 9, 17, 25,
		64  	33, 41, 49, 57, 2, 10, 18, 26,
		65  	34, 42, 50, 58, 3, 11, 19, 27,
		66  	35, 43, 51, 59, 36, 44, 52, 60,
		67  }
		68  
		69  // Used in the key schedule to produce each subkey by selecting 48 bits from
		70  // the 56-bit input
		71  var permutedChoice2 = [48]byte{
		72  	42, 39, 45, 32, 55, 51, 53, 28,
		73  	41, 50, 35, 46, 33, 37, 44, 52,
		74  	30, 48, 40, 49, 29, 36, 43, 54,
		75  	15, 4, 25, 19, 9, 1, 26, 16,
		76  	5, 11, 23, 8, 12, 7, 17, 0,
		77  	22, 3, 10, 14, 6, 20, 27, 24,
		78  }
		79  
		80  // 8 S-boxes composed of 4 rows and 16 columns
		81  // Used in the DES cipher function
		82  var sBoxes = [8][4][16]uint8{
		83  	// S-box 1
		84  	{
		85  		{14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7},
		86  		{0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8},
		87  		{4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0},
		88  		{15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13},
		89  	},
		90  	// S-box 2
		91  	{
		92  		{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},
		93  		{3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5},
		94  		{0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15},
		95  		{13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9},
		96  	},
		97  	// S-box 3
		98  	{
		99  		{10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8},
	 100  		{13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1},
	 101  		{13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7},
	 102  		{1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12},
	 103  	},
	 104  	// S-box 4
	 105  	{
	 106  		{7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15},
	 107  		{13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9},
	 108  		{10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4},
	 109  		{3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14},
	 110  	},
	 111  	// S-box 5
	 112  	{
	 113  		{2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9},
	 114  		{14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6},
	 115  		{4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14},
	 116  		{11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3},
	 117  	},
	 118  	// S-box 6
	 119  	{
	 120  		{12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11},
	 121  		{10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8},
	 122  		{9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6},
	 123  		{4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13},
	 124  	},
	 125  	// S-box 7
	 126  	{
	 127  		{4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1},
	 128  		{13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6},
	 129  		{1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2},
	 130  		{6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12},
	 131  	},
	 132  	// S-box 8
	 133  	{
	 134  		{13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7},
	 135  		{1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2},
	 136  		{7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8},
	 137  		{2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11},
	 138  	},
	 139  }
	 140  
	 141  // Size of left rotation per round in each half of the key schedule
	 142  var ksRotations = [16]uint8{1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1}
	 143
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