blake2b_generic.go

Documentation: golang.org/x/crypto/blake2b

     1  // Copyright 2016 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 blake2b
     6  
     7  import (
     8  	"encoding/binary"
     9  	"math/bits"
    10  )
    11  
    12  // the precomputed values for BLAKE2b
    13  // there are 12 16-byte arrays - one for each round
    14  // the entries are calculated from the sigma constants.
    15  var precomputed = [12][16]byte{
    16  	{0, 2, 4, 6, 1, 3, 5, 7, 8, 10, 12, 14, 9, 11, 13, 15},
    17  	{14, 4, 9, 13, 10, 8, 15, 6, 1, 0, 11, 5, 12, 2, 7, 3},
    18  	{11, 12, 5, 15, 8, 0, 2, 13, 10, 3, 7, 9, 14, 6, 1, 4},
    19  	{7, 3, 13, 11, 9, 1, 12, 14, 2, 5, 4, 15, 6, 10, 0, 8},
    20  	{9, 5, 2, 10, 0, 7, 4, 15, 14, 11, 6, 3, 1, 12, 8, 13},
    21  	{2, 6, 0, 8, 12, 10, 11, 3, 4, 7, 15, 1, 13, 5, 14, 9},
    22  	{12, 1, 14, 4, 5, 15, 13, 10, 0, 6, 9, 8, 7, 3, 2, 11},
    23  	{13, 7, 12, 3, 11, 14, 1, 9, 5, 15, 8, 2, 0, 4, 6, 10},
    24  	{6, 14, 11, 0, 15, 9, 3, 8, 12, 13, 1, 10, 2, 7, 4, 5},
    25  	{10, 8, 7, 1, 2, 4, 6, 5, 15, 9, 3, 13, 11, 14, 12, 0},
    26  	{0, 2, 4, 6, 1, 3, 5, 7, 8, 10, 12, 14, 9, 11, 13, 15}, // equal to the first
    27  	{14, 4, 9, 13, 10, 8, 15, 6, 1, 0, 11, 5, 12, 2, 7, 3}, // equal to the second
    28  }
    29  
    30  func hashBlocksGeneric(h *[8]uint64, c *[2]uint64, flag uint64, blocks []byte) {
    31  	var m [16]uint64
    32  	c0, c1 := c[0], c[1]
    33  
    34  	for i := 0; i < len(blocks); {
    35  		c0 += BlockSize
    36  		if c0 < BlockSize {
    37  			c1++
    38  		}
    39  
    40  		v0, v1, v2, v3, v4, v5, v6, v7 := h[0], h[1], h[2], h[3], h[4], h[5], h[6], h[7]
    41  		v8, v9, v10, v11, v12, v13, v14, v15 := iv[0], iv[1], iv[2], iv[3], iv[4], iv[5], iv[6], iv[7]
    42  		v12 ^= c0
    43  		v13 ^= c1
    44  		v14 ^= flag
    45  
    46  		for j := range m {
    47  			m[j] = binary.LittleEndian.Uint64(blocks[i:])
    48  			i += 8
    49  		}
    50  
    51  		for j := range precomputed {
    52  			s := &(precomputed[j])
    53  
    54  			v0 += m[s[0]]
    55  			v0 += v4
    56  			v12 ^= v0
    57  			v12 = bits.RotateLeft64(v12, -32)
    58  			v8 += v12
    59  			v4 ^= v8
    60  			v4 = bits.RotateLeft64(v4, -24)
    61  			v1 += m[s[1]]
    62  			v1 += v5
    63  			v13 ^= v1
    64  			v13 = bits.RotateLeft64(v13, -32)
    65  			v9 += v13
    66  			v5 ^= v9
    67  			v5 = bits.RotateLeft64(v5, -24)
    68  			v2 += m[s[2]]
    69  			v2 += v6
    70  			v14 ^= v2
    71  			v14 = bits.RotateLeft64(v14, -32)
    72  			v10 += v14
    73  			v6 ^= v10
    74  			v6 = bits.RotateLeft64(v6, -24)
    75  			v3 += m[s[3]]
    76  			v3 += v7
    77  			v15 ^= v3
    78  			v15 = bits.RotateLeft64(v15, -32)
    79  			v11 += v15
    80  			v7 ^= v11
    81  			v7 = bits.RotateLeft64(v7, -24)
    82  
    83  			v0 += m[s[4]]
    84  			v0 += v4
    85  			v12 ^= v0
    86  			v12 = bits.RotateLeft64(v12, -16)
    87  			v8 += v12
    88  			v4 ^= v8
    89  			v4 = bits.RotateLeft64(v4, -63)
    90  			v1 += m[s[5]]
    91  			v1 += v5
    92  			v13 ^= v1
    93  			v13 = bits.RotateLeft64(v13, -16)
    94  			v9 += v13
    95  			v5 ^= v9
    96  			v5 = bits.RotateLeft64(v5, -63)
    97  			v2 += m[s[6]]
    98  			v2 += v6
    99  			v14 ^= v2
   100  			v14 = bits.RotateLeft64(v14, -16)
   101  			v10 += v14
   102  			v6 ^= v10
   103  			v6 = bits.RotateLeft64(v6, -63)
   104  			v3 += m[s[7]]
   105  			v3 += v7
   106  			v15 ^= v3
   107  			v15 = bits.RotateLeft64(v15, -16)
   108  			v11 += v15
   109  			v7 ^= v11
   110  			v7 = bits.RotateLeft64(v7, -63)
   111  
   112  			v0 += m[s[8]]
   113  			v0 += v5
   114  			v15 ^= v0
   115  			v15 = bits.RotateLeft64(v15, -32)
   116  			v10 += v15
   117  			v5 ^= v10
   118  			v5 = bits.RotateLeft64(v5, -24)
   119  			v1 += m[s[9]]
   120  			v1 += v6
   121  			v12 ^= v1
   122  			v12 = bits.RotateLeft64(v12, -32)
   123  			v11 += v12
   124  			v6 ^= v11
   125  			v6 = bits.RotateLeft64(v6, -24)
   126  			v2 += m[s[10]]
   127  			v2 += v7
   128  			v13 ^= v2
   129  			v13 = bits.RotateLeft64(v13, -32)
   130  			v8 += v13
   131  			v7 ^= v8
   132  			v7 = bits.RotateLeft64(v7, -24)
   133  			v3 += m[s[11]]
   134  			v3 += v4
   135  			v14 ^= v3
   136  			v14 = bits.RotateLeft64(v14, -32)
   137  			v9 += v14
   138  			v4 ^= v9
   139  			v4 = bits.RotateLeft64(v4, -24)
   140  
   141  			v0 += m[s[12]]
   142  			v0 += v5
   143  			v15 ^= v0
   144  			v15 = bits.RotateLeft64(v15, -16)
   145  			v10 += v15
   146  			v5 ^= v10
   147  			v5 = bits.RotateLeft64(v5, -63)
   148  			v1 += m[s[13]]
   149  			v1 += v6
   150  			v12 ^= v1
   151  			v12 = bits.RotateLeft64(v12, -16)
   152  			v11 += v12
   153  			v6 ^= v11
   154  			v6 = bits.RotateLeft64(v6, -63)
   155  			v2 += m[s[14]]
   156  			v2 += v7
   157  			v13 ^= v2
   158  			v13 = bits.RotateLeft64(v13, -16)
   159  			v8 += v13
   160  			v7 ^= v8
   161  			v7 = bits.RotateLeft64(v7, -63)
   162  			v3 += m[s[15]]
   163  			v3 += v4
   164  			v14 ^= v3
   165  			v14 = bits.RotateLeft64(v14, -16)
   166  			v9 += v14
   167  			v4 ^= v9
   168  			v4 = bits.RotateLeft64(v4, -63)
   169  
   170  		}
   171  
   172  		h[0] ^= v0 ^ v8
   173  		h[1] ^= v1 ^ v9
   174  		h[2] ^= v2 ^ v10
   175  		h[3] ^= v3 ^ v11
   176  		h[4] ^= v4 ^ v12
   177  		h[5] ^= v5 ^ v13
   178  		h[6] ^= v6 ^ v14
   179  		h[7] ^= v7 ^ v15
   180  	}
   181  	c[0], c[1] = c0, c1
   182  }
   183
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