blake2s_generic.go

Documentation: golang.org/x/crypto/blake2s

     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 blake2s
     6  
     7  import (
     8  	"math/bits"
     9  )
    10  
    11  // the precomputed values for BLAKE2s
    12  // there are 10 16-byte arrays - one for each round
    13  // the entries are calculated from the sigma constants.
    14  var precomputed = [10][16]byte{
    15  	{0, 2, 4, 6, 1, 3, 5, 7, 8, 10, 12, 14, 9, 11, 13, 15},
    16  	{14, 4, 9, 13, 10, 8, 15, 6, 1, 0, 11, 5, 12, 2, 7, 3},
    17  	{11, 12, 5, 15, 8, 0, 2, 13, 10, 3, 7, 9, 14, 6, 1, 4},
    18  	{7, 3, 13, 11, 9, 1, 12, 14, 2, 5, 4, 15, 6, 10, 0, 8},
    19  	{9, 5, 2, 10, 0, 7, 4, 15, 14, 11, 6, 3, 1, 12, 8, 13},
    20  	{2, 6, 0, 8, 12, 10, 11, 3, 4, 7, 15, 1, 13, 5, 14, 9},
    21  	{12, 1, 14, 4, 5, 15, 13, 10, 0, 6, 9, 8, 7, 3, 2, 11},
    22  	{13, 7, 12, 3, 11, 14, 1, 9, 5, 15, 8, 2, 0, 4, 6, 10},
    23  	{6, 14, 11, 0, 15, 9, 3, 8, 12, 13, 1, 10, 2, 7, 4, 5},
    24  	{10, 8, 7, 1, 2, 4, 6, 5, 15, 9, 3, 13, 11, 14, 12, 0},
    25  }
    26  
    27  func hashBlocksGeneric(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte) {
    28  	var m [16]uint32
    29  	c0, c1 := c[0], c[1]
    30  
    31  	for i := 0; i < len(blocks); {
    32  		c0 += BlockSize
    33  		if c0 < BlockSize {
    34  			c1++
    35  		}
    36  
    37  		v0, v1, v2, v3, v4, v5, v6, v7 := h[0], h[1], h[2], h[3], h[4], h[5], h[6], h[7]
    38  		v8, v9, v10, v11, v12, v13, v14, v15 := iv[0], iv[1], iv[2], iv[3], iv[4], iv[5], iv[6], iv[7]
    39  		v12 ^= c0
    40  		v13 ^= c1
    41  		v14 ^= flag
    42  
    43  		for j := range m {
    44  			m[j] = uint32(blocks[i]) | uint32(blocks[i+1])<<8 | uint32(blocks[i+2])<<16 | uint32(blocks[i+3])<<24
    45  			i += 4
    46  		}
    47  
    48  		for k := range precomputed {
    49  			s := &(precomputed[k])
    50  
    51  			v0 += m[s[0]]
    52  			v0 += v4
    53  			v12 ^= v0
    54  			v12 = bits.RotateLeft32(v12, -16)
    55  			v8 += v12
    56  			v4 ^= v8
    57  			v4 = bits.RotateLeft32(v4, -12)
    58  			v1 += m[s[1]]
    59  			v1 += v5
    60  			v13 ^= v1
    61  			v13 = bits.RotateLeft32(v13, -16)
    62  			v9 += v13
    63  			v5 ^= v9
    64  			v5 = bits.RotateLeft32(v5, -12)
    65  			v2 += m[s[2]]
    66  			v2 += v6
    67  			v14 ^= v2
    68  			v14 = bits.RotateLeft32(v14, -16)
    69  			v10 += v14
    70  			v6 ^= v10
    71  			v6 = bits.RotateLeft32(v6, -12)
    72  			v3 += m[s[3]]
    73  			v3 += v7
    74  			v15 ^= v3
    75  			v15 = bits.RotateLeft32(v15, -16)
    76  			v11 += v15
    77  			v7 ^= v11
    78  			v7 = bits.RotateLeft32(v7, -12)
    79  
    80  			v0 += m[s[4]]
    81  			v0 += v4
    82  			v12 ^= v0
    83  			v12 = bits.RotateLeft32(v12, -8)
    84  			v8 += v12
    85  			v4 ^= v8
    86  			v4 = bits.RotateLeft32(v4, -7)
    87  			v1 += m[s[5]]
    88  			v1 += v5
    89  			v13 ^= v1
    90  			v13 = bits.RotateLeft32(v13, -8)
    91  			v9 += v13
    92  			v5 ^= v9
    93  			v5 = bits.RotateLeft32(v5, -7)
    94  			v2 += m[s[6]]
    95  			v2 += v6
    96  			v14 ^= v2
    97  			v14 = bits.RotateLeft32(v14, -8)
    98  			v10 += v14
    99  			v6 ^= v10
   100  			v6 = bits.RotateLeft32(v6, -7)
   101  			v3 += m[s[7]]
   102  			v3 += v7
   103  			v15 ^= v3
   104  			v15 = bits.RotateLeft32(v15, -8)
   105  			v11 += v15
   106  			v7 ^= v11
   107  			v7 = bits.RotateLeft32(v7, -7)
   108  
   109  			v0 += m[s[8]]
   110  			v0 += v5
   111  			v15 ^= v0
   112  			v15 = bits.RotateLeft32(v15, -16)
   113  			v10 += v15
   114  			v5 ^= v10
   115  			v5 = bits.RotateLeft32(v5, -12)
   116  			v1 += m[s[9]]
   117  			v1 += v6
   118  			v12 ^= v1
   119  			v12 = bits.RotateLeft32(v12, -16)
   120  			v11 += v12
   121  			v6 ^= v11
   122  			v6 = bits.RotateLeft32(v6, -12)
   123  			v2 += m[s[10]]
   124  			v2 += v7
   125  			v13 ^= v2
   126  			v13 = bits.RotateLeft32(v13, -16)
   127  			v8 += v13
   128  			v7 ^= v8
   129  			v7 = bits.RotateLeft32(v7, -12)
   130  			v3 += m[s[11]]
   131  			v3 += v4
   132  			v14 ^= v3
   133  			v14 = bits.RotateLeft32(v14, -16)
   134  			v9 += v14
   135  			v4 ^= v9
   136  			v4 = bits.RotateLeft32(v4, -12)
   137  
   138  			v0 += m[s[12]]
   139  			v0 += v5
   140  			v15 ^= v0
   141  			v15 = bits.RotateLeft32(v15, -8)
   142  			v10 += v15
   143  			v5 ^= v10
   144  			v5 = bits.RotateLeft32(v5, -7)
   145  			v1 += m[s[13]]
   146  			v1 += v6
   147  			v12 ^= v1
   148  			v12 = bits.RotateLeft32(v12, -8)
   149  			v11 += v12
   150  			v6 ^= v11
   151  			v6 = bits.RotateLeft32(v6, -7)
   152  			v2 += m[s[14]]
   153  			v2 += v7
   154  			v13 ^= v2
   155  			v13 = bits.RotateLeft32(v13, -8)
   156  			v8 += v13
   157  			v7 ^= v8
   158  			v7 = bits.RotateLeft32(v7, -7)
   159  			v3 += m[s[15]]
   160  			v3 += v4
   161  			v14 ^= v3
   162  			v14 = bits.RotateLeft32(v14, -8)
   163  			v9 += v14
   164  			v4 ^= v9
   165  			v4 = bits.RotateLeft32(v4, -7)
   166  		}
   167  
   168  		h[0] ^= v0 ^ v8
   169  		h[1] ^= v1 ^ v9
   170  		h[2] ^= v2 ^ v10
   171  		h[3] ^= v3 ^ v11
   172  		h[4] ^= v4 ^ v12
   173  		h[5] ^= v5 ^ v13
   174  		h[6] ^= v6 ^ v14
   175  		h[7] ^= v7 ^ v15
   176  	}
   177  	c[0], c[1] = c0, c1
   178  }
   179
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