const.go

     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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