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Diffstat (limited to 'vendor/golang.org/x/crypto/md4/md4block.go')
-rw-r--r--vendor/golang.org/x/crypto/md4/md4block.go89
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
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+++ b/vendor/golang.org/x/crypto/md4/md4block.go
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+// 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
+}