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 // +build !386,!amd64
   6
   7 // SHA256 block step.
   8 // In its own file so that a faster assembly or C version
   9 // can be substituted easily.
  10
  11 package sha256
  12
  13 var _K = []uint32{
  14         0x428a2f98,
  15         0x71374491,
  16         0xb5c0fbcf,
  17         0xe9b5dba5,
  18         0x3956c25b,
  19         0x59f111f1,
  20         0x923f82a4,
  21         0xab1c5ed5,
  22         0xd807aa98,
  23         0x12835b01,
  24         0x243185be,
  25         0x550c7dc3,
  26         0x72be5d74,
  27         0x80deb1fe,
  28         0x9bdc06a7,
  29         0xc19bf174,
  30         0xe49b69c1,
  31         0xefbe4786,
  32         0x0fc19dc6,
  33         0x240ca1cc,
  34         0x2de92c6f,
  35         0x4a7484aa,
  36         0x5cb0a9dc,
  37         0x76f988da,
  38         0x983e5152,
  39         0xa831c66d,
  40         0xb00327c8,
  41         0xbf597fc7,
  42         0xc6e00bf3,
  43         0xd5a79147,
  44         0x06ca6351,
  45         0x14292967,
  46         0x27b70a85,
  47         0x2e1b2138,
  48         0x4d2c6dfc,
  49         0x53380d13,
  50         0x650a7354,
  51         0x766a0abb,
  52         0x81c2c92e,
  53         0x92722c85,
  54         0xa2bfe8a1,
  55         0xa81a664b,
  56         0xc24b8b70,
  57         0xc76c51a3,
  58         0xd192e819,
  59         0xd6990624,
  60         0xf40e3585,
  61         0x106aa070,
  62         0x19a4c116,
  63         0x1e376c08,
  64         0x2748774c,
  65         0x34b0bcb5,
  66         0x391c0cb3,
  67         0x4ed8aa4a,
  68         0x5b9cca4f,
  69         0x682e6ff3,
  70         0x748f82ee,
  71         0x78a5636f,
  72         0x84c87814,
  73         0x8cc70208,
  74         0x90befffa,
  75         0xa4506ceb,
  76         0xbef9a3f7,
  77         0xc67178f2,
  78 }
  79
  80 func block(dig *digest, p []byte) {
  81         var w [64]uint32
  82         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]
  83         for len(p) >= chunk {
  84                 // Can interlace the computation of w with the
  85                 // rounds below if needed for speed.
  86                 for i := 0; i < 16; i++ {
  87                         j := i * 4
  88                         w[i] = uint32(p[j])<<24 | uint32(p[j+1])<<16 | uint32(p[j+2])<<8 | uint32(p[j+3])
  89                 }
  90                 for i := 16; i < 64; i++ {
  91                         v1 := w[i-2]
  92                         t1 := (v1>>17 | v1<<(32-17)) ^ (v1>>19 | v1<<(32-19)) ^ (v1 >> 10)
  93                         v2 := w[i-15]
  94                         t2 := (v2>>7 | v2<<(32-7)) ^ (v2>>18 | v2<<(32-18)) ^ (v2 >> 3)
  95                         w[i] = t1 + w[i-7] + t2 + w[i-16]
  96                 }
  97
  98                 a, b, c, d, e, f, g, h := h0, h1, h2, h3, h4, h5, h6, h7
  99
 100                 for i := 0; i < 64; i++ {
 101                         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]
 102
 103                         t2 := ((a>>2 | a<<(32-2)) ^ (a>>13 | a<<(32-13)) ^ (a>>22 | a<<(32-22))) + ((a & b) ^ (a & c) ^ (b & c))
 104
 105                         h = g
 106                         g = f
 107                         f = e
 108                         e = d + t1
 109                         d = c
 110                         c = b
 111                         b = a
 112                         a = t1 + t2
 113                 }
 114
 115                 h0 += a
 116                 h1 += b
 117                 h2 += c
 118                 h3 += d
 119                 h4 += e
 120                 h5 += f
 121                 h6 += g
 122                 h7 += h
 123
 124                 p = p[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 }