libgo/go/crypto/sha256/sha256block.go

   1 // Copyright 2009 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 // SHA256 block step.
   6 // In its own file so that a faster assembly or C version
   7 // can be substituted easily.
   8
   9 package sha256
  10
  11 var _K = []uint32{
  12         0x428a2f98,
  13         0x71374491,
  14         0xb5c0fbcf,
  15         0xe9b5dba5,
  16         0x3956c25b,
  17         0x59f111f1,
  18         0x923f82a4,
  19         0xab1c5ed5,
  20         0xd807aa98,
  21         0x12835b01,
  22         0x243185be,
  23         0x550c7dc3,
  24         0x72be5d74,
  25         0x80deb1fe,
  26         0x9bdc06a7,
  27         0xc19bf174,
  28         0xe49b69c1,
  29         0xefbe4786,
  30         0x0fc19dc6,
  31         0x240ca1cc,
  32         0x2de92c6f,
  33         0x4a7484aa,
  34         0x5cb0a9dc,
  35         0x76f988da,
  36         0x983e5152,
  37         0xa831c66d,
  38         0xb00327c8,
  39         0xbf597fc7,
  40         0xc6e00bf3,
  41         0xd5a79147,
  42         0x06ca6351,
  43         0x14292967,
  44         0x27b70a85,
  45         0x2e1b2138,
  46         0x4d2c6dfc,
  47         0x53380d13,
  48         0x650a7354,
  49         0x766a0abb,
  50         0x81c2c92e,
  51         0x92722c85,
  52         0xa2bfe8a1,
  53         0xa81a664b,
  54         0xc24b8b70,
  55         0xc76c51a3,
  56         0xd192e819,
  57         0xd6990624,
  58         0xf40e3585,
  59         0x106aa070,
  60         0x19a4c116,
  61         0x1e376c08,
  62         0x2748774c,
  63         0x34b0bcb5,
  64         0x391c0cb3,
  65         0x4ed8aa4a,
  66         0x5b9cca4f,
  67         0x682e6ff3,
  68         0x748f82ee,
  69         0x78a5636f,
  70         0x84c87814,
  71         0x8cc70208,
  72         0x90befffa,
  73         0xa4506ceb,
  74         0xbef9a3f7,
  75         0xc67178f2,
  76 }
  77
  78 func _Block(dig *digest, p []byte) int {
  79         var w [64]uint32
  80         n := 0
  81         h0, h1, h2, h3, h4, h5, h6, h7 := dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7]
  82         for len(p) >= _Chunk {
  83                 // Can interlace the computation of w with the
  84                 // rounds below if needed for speed.
  85                 for i := 0; i < 16; i++ {
  86                         j := i * 4
  87                         w[i] = uint32(p[j])<<24 | uint32(p[j+1])<<16 | uint32(p[j+2])<<8 | uint32(p[j+3])
  88                 }
  89                 for i := 16; i < 64; i++ {
  90                         t1 := (w[i-2]>>17 | w[i-2]<<(32-17)) ^ (w[i-2]>>19 | w[i-2]<<(32-19)) ^ (w[i-2] >> 10)
  91
  92                         t2 := (w[i-15]>>7 | w[i-15]<<(32-7)) ^ (w[i-15]>>18 | w[i-15]<<(32-18)) ^ (w[i-15] >> 3)
  93
  94                         w[i] = t1 + w[i-7] + t2 + w[i-16]
  95                 }
  96
  97                 a, b, c, d, e, f, g, h := h0, h1, h2, h3, h4, h5, h6, h7
  98
  99                 for i := 0; i < 64; i++ {
 100                         t1 := h + ((e>>6 | e<<(32-6)) ^ (e>>11 | e<<(32-11)) ^ (e>>25 | e<<(32-25))) + ((e & f) ^ (^e & g)) + _K[i] + w[i]
 101
 102                         t2 := ((a>>2 | a<<(32-2)) ^ (a>>13 | a<<(32-13)) ^ (a>>22 | a<<(32-22))) + ((a & b) ^ (a & c) ^ (b & c))
 103
 104                         h = g
 105                         g = f
 106                         f = e
 107                         e = d + t1
 108                         d = c
 109                         c = b
 110                         b = a
 111                         a = t1 + t2
 112                 }
 113
 114                 h0 += a
 115                 h1 += b
 116                 h2 += c
 117                 h3 += d
 118                 h4 += e
 119                 h5 += f
 120                 h6 += g
 121                 h7 += h
 122
 123                 p = p[_Chunk:]
 124                 n += _Chunk
 125         }
 126
 127         dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7] = h0, h1, h2, h3, h4, h5, h6, h7
 128         return n
 129 }