1 files changed, 172 insertions, 0 deletions
diff --git a/libgo/go/crypto/md5/md5block.go b/libgo/go/crypto/md5/md5block.go
new file mode 100644
index 0000000000..a887e2e05e
--- /dev/null
+++ b/libgo/go/crypto/md5/md5block.go
@@ -0,0 +1,172 @@
+// 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.
+
+// MD5 block step.
+// In its own file so that a faster assembly or C version
+// can be substituted easily.
+
+package md5
+
+// table[i] = int((1<<32) * abs(sin(i+1 radians))).
+var table = []uint32{
+	// round 1
+	0xd76aa478,
+	0xe8c7b756,
+	0x242070db,
+	0xc1bdceee,
+	0xf57c0faf,
+	0x4787c62a,
+	0xa8304613,
+	0xfd469501,
+	0x698098d8,
+	0x8b44f7af,
+	0xffff5bb1,
+	0x895cd7be,
+	0x6b901122,
+	0xfd987193,
+	0xa679438e,
+	0x49b40821,
+
+	// round 2
+	0xf61e2562,
+	0xc040b340,
+	0x265e5a51,
+	0xe9b6c7aa,
+	0xd62f105d,
+	0x2441453,
+	0xd8a1e681,
+	0xe7d3fbc8,
+	0x21e1cde6,
+	0xc33707d6,
+	0xf4d50d87,
+	0x455a14ed,
+	0xa9e3e905,
+	0xfcefa3f8,
+	0x676f02d9,
+	0x8d2a4c8a,
+
+	// round3
+	0xfffa3942,
+	0x8771f681,
+	0x6d9d6122,
+	0xfde5380c,
+	0xa4beea44,
+	0x4bdecfa9,
+	0xf6bb4b60,
+	0xbebfbc70,
+	0x289b7ec6,
+	0xeaa127fa,
+	0xd4ef3085,
+	0x4881d05,
+	0xd9d4d039,
+	0xe6db99e5,
+	0x1fa27cf8,
+	0xc4ac5665,
+
+	// round 4
+	0xf4292244,
+	0x432aff97,
+	0xab9423a7,
+	0xfc93a039,
+	0x655b59c3,
+	0x8f0ccc92,
+	0xffeff47d,
+	0x85845dd1,
+	0x6fa87e4f,
+	0xfe2ce6e0,
+	0xa3014314,
+	0x4e0811a1,
+	0xf7537e82,
+	0xbd3af235,
+	0x2ad7d2bb,
+	0xeb86d391,
+}
+
+var shift1 = []uint{7, 12, 17, 22}
+var shift2 = []uint{5, 9, 14, 20}
+var shift3 = []uint{4, 11, 16, 23}
+var shift4 = []uint{6, 10, 15, 21}
+
+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] + table[i]
+			a = a<<s | a>>(32-s) + b
+			a, b, c, d = d, a, b, c
+		}
+
+		// Round 2.
+		for i := uint(0); i < 16; i++ {
+			x := (1 + 5*i) % 16
+			s := shift2[i%4]
+			g := ((b ^ c) & d) ^ c
+			a += g + X[x] + table[i+16]
+			a = a<<s | a>>(32-s) + b
+			a, b, c, d = d, a, b, c
+		}
+
+		// Round 3.
+		for i := uint(0); i < 16; i++ {
+			x := (5 + 3*i) % 16
+			s := shift3[i%4]
+			h := b ^ c ^ d
+			a += h + X[x] + table[i+32]
+			a = a<<s | a>>(32-s) + b
+			a, b, c, d = d, a, b, c
+		}
+
+		// Round 4.
+		for i := uint(0); i < 16; i++ {
+			x := (7 * i) % 16
+			s := shift4[i%4]
+			j := c ^ (b | ^d)
+			a += j + X[x] + table[i+48]
+			a = a<<s | a>>(32-s) + b
+			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
+}