diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/md4/md4block.go')
-rw-r--r-- | vendor/golang.org/x/crypto/md4/md4block.go | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/md4/md4block.go b/vendor/golang.org/x/crypto/md4/md4block.go new file mode 100644 index 0000000..3fed475 --- /dev/null +++ b/vendor/golang.org/x/crypto/md4/md4block.go @@ -0,0 +1,89 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// MD4 block step. +// In its own file so that a faster assembly or C version +// can be substituted easily. + +package md4 + +var shift1 = []uint{3, 7, 11, 19} +var shift2 = []uint{3, 5, 9, 13} +var shift3 = []uint{3, 9, 11, 15} + +var xIndex2 = []uint{0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15} +var xIndex3 = []uint{0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15} + +func _Block(dig *digest, p []byte) int { + a := dig.s[0] + b := dig.s[1] + c := dig.s[2] + d := dig.s[3] + n := 0 + var X [16]uint32 + for len(p) >= _Chunk { + aa, bb, cc, dd := a, b, c, d + + j := 0 + for i := 0; i < 16; i++ { + X[i] = uint32(p[j]) | uint32(p[j+1])<<8 | uint32(p[j+2])<<16 | uint32(p[j+3])<<24 + j += 4 + } + + // If this needs to be made faster in the future, + // the usual trick is to unroll each of these + // loops by a factor of 4; that lets you replace + // the shift[] lookups with constants and, + // with suitable variable renaming in each + // unrolled body, delete the a, b, c, d = d, a, b, c + // (or you can let the optimizer do the renaming). + // + // The index variables are uint so that % by a power + // of two can be optimized easily by a compiler. + + // Round 1. + for i := uint(0); i < 16; i++ { + x := i + s := shift1[i%4] + f := ((c ^ d) & b) ^ d + a += f + X[x] + a = a<<s | a>>(32-s) + a, b, c, d = d, a, b, c + } + + // Round 2. + for i := uint(0); i < 16; i++ { + x := xIndex2[i] + s := shift2[i%4] + g := (b & c) | (b & d) | (c & d) + a += g + X[x] + 0x5a827999 + a = a<<s | a>>(32-s) + a, b, c, d = d, a, b, c + } + + // Round 3. + for i := uint(0); i < 16; i++ { + x := xIndex3[i] + s := shift3[i%4] + h := b ^ c ^ d + a += h + X[x] + 0x6ed9eba1 + a = a<<s | a>>(32-s) + a, b, c, d = d, a, b, c + } + + a += aa + b += bb + c += cc + d += dd + + p = p[_Chunk:] + n += _Chunk + } + + dig.s[0] = a + dig.s[1] = b + dig.s[2] = c + dig.s[3] = d + return n +} |