crypto/blowfish: new package

R=rsc
CC=golang-dev
https://golang.org/cl/217116

src/pkg/Makefile

@@ -35,6 +35,7 @@ DIRS=\
 	container/vector\
 	crypto/aes\
 	crypto/block\
+	crypto/blowfish\
 	crypto/hmac\
 	crypto/md4\
 	crypto/md5\

src/pkg/crypto/blowfish/Makefile

+# Copyright 2010 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.
+
+include ../../../Make.$(GOARCH)
+
+TARG=crypto/blowfish
+GOFILES=\
+	block.go\
+	cipher.go\
+	const.go\
+
+include ../../../Make.pkg

src/pkg/crypto/blowfish/block.go

+// Copyright 2010 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.
+
+package blowfish
+
+func expandKey(key []byte, c *Cipher) {
+	copy(&c.p, &p)
+	copy(&c.s0, &s0)
+	copy(&c.s1, &s1)
+	copy(&c.s2, &s2)
+	copy(&c.s3, &s3)
+
+	j := 0
+	for i := 0; i < 18; i++ {
+		var d uint32
+		for k := 0; k < 4; k++ {
+			d = d<<8 | uint32(key[j])&0x000000FF
+			j++
+			if j >= len(key) {
+				j = 0
+			}
+		}
+		c.p[i] ^= d
+	}
+
+	var l, r uint32
+	for i := 0; i < 18; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.p[i], c.p[i+1] = l, r
+	}
+
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s0[i], c.s0[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s1[i], c.s1[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s2[i], c.s2[i+1] = l, r
+	}
+	for i := 0; i < 256; i += 2 {
+		l, r = encryptBlock(l, r, c)
+		c.s3[i], c.s3[i+1] = l, r
+	}
+}
+
+func encryptBlock(l, r uint32, c *Cipher) (uint32, uint32) {
+	xl, xr := l, r
+	xl ^= c.p[0]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[1]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[2]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[3]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[4]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[5]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[6]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[7]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[8]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[9]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[10]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[11]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[12]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[13]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[14]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[15]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[16]
+	xr ^= c.p[17]
+	return xr, xl
+}
+
+func decryptBlock(l, r uint32, c *Cipher) (uint32, uint32) {
+	xl, xr := l, r
+	xl ^= c.p[17]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[16]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[15]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[14]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[13]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[12]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[11]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[10]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[9]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[8]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[7]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[6]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[5]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[4]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[3]
+	xr ^= ((c.s0[byte(xl>>24)] + c.s1[byte(xl>>16)]) ^ c.s2[byte(xl>>8)]) + c.s3[byte(xl)] ^ c.p[2]
+	xl ^= ((c.s0[byte(xr>>24)] + c.s1[byte(xr>>16)]) ^ c.s2[byte(xr>>8)]) + c.s3[byte(xr)] ^ c.p[1]
+	xr ^= c.p[0]
+	return xr, xl
+}
+
+func zero(x []uint32) {
+	for i := range x {
+		x[i] = 0
+	}
+}

src/pkg/crypto/blowfish/blowfish_test.go

+// Copyright 2010 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.
+
+package blowfish
+
+import (
+	"testing"
+)
+
+type CryptTest struct {
+	key []byte
+	in  []byte
+	out []byte
+}
+
+// Test vector values are from http://www.schneier.com/code/vectors.txt.
+var encryptTests = []CryptTest{
+	CryptTest{
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0x4E, 0xF9, 0x97, 0x45, 0x61, 0x98, 0xDD, 0x78}},
+	CryptTest{
+		[]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
+		[]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
+		[]byte{0x51, 0x86, 0x6F, 0xD5, 0xB8, 0x5E, 0xCB, 0x8A}},
+	CryptTest{
+		[]byte{0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01},
+		[]byte{0x7D, 0x85, 0x6F, 0x9A, 0x61, 0x30, 0x63, 0xF2}},
+	CryptTest{
+		[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11},
+		[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11},
+		[]byte{0x24, 0x66, 0xDD, 0x87, 0x8B, 0x96, 0x3C, 0x9D}},
+
+	CryptTest{
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+		[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11},
+		[]byte{0x61, 0xF9, 0xC3, 0x80, 0x22, 0x81, 0xB0, 0x96}},
+	CryptTest{
+		[]byte{0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11},
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+		[]byte{0x7D, 0x0C, 0xC6, 0x30, 0xAF, 0xDA, 0x1E, 0xC7}},
+	CryptTest{
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0x4E, 0xF9, 0x97, 0x45, 0x61, 0x98, 0xDD, 0x78}},
+	CryptTest{
+		[]byte{0xFE, 0xDC, 0xBA, 0x98, 0x76, 0x54, 0x32, 0x10},
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+		[]byte{0x0A, 0xCE, 0xAB, 0x0F, 0xC6, 0xA0, 0xA2, 0x8D}},
+	CryptTest{
+		[]byte{0x7C, 0xA1, 0x10, 0x45, 0x4A, 0x1A, 0x6E, 0x57},
+		[]byte{0x01, 0xA1, 0xD6, 0xD0, 0x39, 0x77, 0x67, 0x42},
+		[]byte{0x59, 0xC6, 0x82, 0x45, 0xEB, 0x05, 0x28, 0x2B}},
+	CryptTest{
+		[]byte{0x01, 0x31, 0xD9, 0x61, 0x9D, 0xC1, 0x37, 0x6E},
+		[]byte{0x5C, 0xD5, 0x4C, 0xA8, 0x3D, 0xEF, 0x57, 0xDA},
+		[]byte{0xB1, 0xB8, 0xCC, 0x0B, 0x25, 0x0F, 0x09, 0xA0}},
+	CryptTest{
+		[]byte{0x07, 0xA1, 0x13, 0x3E, 0x4A, 0x0B, 0x26, 0x86},
+		[]byte{0x02, 0x48, 0xD4, 0x38, 0x06, 0xF6, 0x71, 0x72},
+		[]byte{0x17, 0x30, 0xE5, 0x77, 0x8B, 0xEA, 0x1D, 0xA4}},
+	CryptTest{
+		[]byte{0x38, 0x49, 0x67, 0x4C, 0x26, 0x02, 0x31, 0x9E},
+		[]byte{0x51, 0x45, 0x4B, 0x58, 0x2D, 0xDF, 0x44, 0x0A},
+		[]byte{0xA2, 0x5E, 0x78, 0x56, 0xCF, 0x26, 0x51, 0xEB}},
+	CryptTest{
+		[]byte{0x04, 0xB9, 0x15, 0xBA, 0x43, 0xFE, 0xB5, 0xB6},
+		[]byte{0x42, 0xFD, 0x44, 0x30, 0x59, 0x57, 0x7F, 0xA2},
+		[]byte{0x35, 0x38, 0x82, 0xB1, 0x09, 0xCE, 0x8F, 0x1A}},
+	CryptTest{
+		[]byte{0x01, 0x13, 0xB9, 0x70, 0xFD, 0x34, 0xF2, 0xCE},
+		[]byte{0x05, 0x9B, 0x5E, 0x08, 0x51, 0xCF, 0x14, 0x3A},
+		[]byte{0x48, 0xF4, 0xD0, 0x88, 0x4C, 0x37, 0x99, 0x18}},
+	CryptTest{
+		[]byte{0x01, 0x70, 0xF1, 0x75, 0x46, 0x8F, 0xB5, 0xE6},
+		[]byte{0x07, 0x56, 0xD8, 0xE0, 0x77, 0x47, 0x61, 0xD2},
+		[]byte{0x43, 0x21, 0x93, 0xB7, 0x89, 0x51, 0xFC, 0x98}},
+	CryptTest{
+		[]byte{0x43, 0x29, 0x7F, 0xAD, 0x38, 0xE3, 0x73, 0xFE},
+		[]byte{0x76, 0x25, 0x14, 0xB8, 0x29, 0xBF, 0x48, 0x6A},
+		[]byte{0x13, 0xF0, 0x41, 0x54, 0xD6, 0x9D, 0x1A, 0xE5}},
+	CryptTest{
+		[]byte{0x07, 0xA7, 0x13, 0x70, 0x45, 0xDA, 0x2A, 0x16},
+		[]byte{0x3B, 0xDD, 0x11, 0x90, 0x49, 0x37, 0x28, 0x02},
+		[]byte{0x2E, 0xED, 0xDA, 0x93, 0xFF, 0xD3, 0x9C, 0x79}},
+	CryptTest{
+		[]byte{0x04, 0x68, 0x91, 0x04, 0xC2, 0xFD, 0x3B, 0x2F},
+		[]byte{0x26, 0x95, 0x5F, 0x68, 0x35, 0xAF, 0x60, 0x9A},
+		[]byte{0xD8, 0x87, 0xE0, 0x39, 0x3C, 0x2D, 0xA6, 0xE3}},
+	CryptTest{
+		[]byte{0x37, 0xD0, 0x6B, 0xB5, 0x16, 0xCB, 0x75, 0x46},
+		[]byte{0x16, 0x4D, 0x5E, 0x40, 0x4F, 0x27, 0x52, 0x32},
+		[]byte{0x5F, 0x99, 0xD0, 0x4F, 0x5B, 0x16, 0x39, 0x69}},
+	CryptTest{
+		[]byte{0x1F, 0x08, 0x26, 0x0D, 0x1A, 0xC2, 0x46, 0x5E},
+		[]byte{0x6B, 0x05, 0x6E, 0x18, 0x75, 0x9F, 0x5C, 0xCA},
+		[]byte{0x4A, 0x05, 0x7A, 0x3B, 0x24, 0xD3, 0x97, 0x7B}},
+	CryptTest{
+		[]byte{0x58, 0x40, 0x23, 0x64, 0x1A, 0xBA, 0x61, 0x76},
+		[]byte{0x00, 0x4B, 0xD6, 0xEF, 0x09, 0x17, 0x60, 0x62},
+		[]byte{0x45, 0x20, 0x31, 0xC1, 0xE4, 0xFA, 0xDA, 0x8E}},
+	CryptTest{
+		[]byte{0x02, 0x58, 0x16, 0x16, 0x46, 0x29, 0xB0, 0x07},
+		[]byte{0x48, 0x0D, 0x39, 0x00, 0x6E, 0xE7, 0x62, 0xF2},
+		[]byte{0x75, 0x55, 0xAE, 0x39, 0xF5, 0x9B, 0x87, 0xBD}},
+	CryptTest{
+		[]byte{0x49, 0x79, 0x3E, 0xBC, 0x79, 0xB3, 0x25, 0x8F},
+		[]byte{0x43, 0x75, 0x40, 0xC8, 0x69, 0x8F, 0x3C, 0xFA},
+		[]byte{0x53, 0xC5, 0x5F, 0x9C, 0xB4, 0x9F, 0xC0, 0x19}},
+	CryptTest{
+		[]byte{0x4F, 0xB0, 0x5E, 0x15, 0x15, 0xAB, 0x73, 0xA7},
+		[]byte{0x07, 0x2D, 0x43, 0xA0, 0x77, 0x07, 0x52, 0x92},
+		[]byte{0x7A, 0x8E, 0x7B, 0xFA, 0x93, 0x7E, 0x89, 0xA3}},
+	CryptTest{
+		[]byte{0x49, 0xE9, 0x5D, 0x6D, 0x4C, 0xA2, 0x29, 0xBF},
+		[]byte{0x02, 0xFE, 0x55, 0x77, 0x81, 0x17, 0xF1, 0x2A},
+		[]byte{0xCF, 0x9C, 0x5D, 0x7A, 0x49, 0x86, 0xAD, 0xB5}},
+	CryptTest{
+		[]byte{0x01, 0x83, 0x10, 0xDC, 0x40, 0x9B, 0x26, 0xD6},
+		[]byte{0x1D, 0x9D, 0x5C, 0x50, 0x18, 0xF7, 0x28, 0xC2},
+		[]byte{0xD1, 0xAB, 0xB2, 0x90, 0x65, 0x8B, 0xC7, 0x78}},
+	CryptTest{
+		[]byte{0x1C, 0x58, 0x7F, 0x1C, 0x13, 0x92, 0x4F, 0xEF},
+		[]byte{0x30, 0x55, 0x32, 0x28, 0x6D, 0x6F, 0x29, 0x5A},
+		[]byte{0x55, 0xCB, 0x37, 0x74, 0xD1, 0x3E, 0xF2, 0x01}},
+	CryptTest{
+		[]byte{0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01},
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+		[]byte{0xFA, 0x34, 0xEC, 0x48, 0x47, 0xB2, 0x68, 0xB2}},
+	CryptTest{
+		[]byte{0x1F, 0x1F, 0x1F, 0x1F, 0x0E, 0x0E, 0x0E, 0x0E},
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+		[]byte{0xA7, 0x90, 0x79, 0x51, 0x08, 0xEA, 0x3C, 0xAE}},
+	CryptTest{
+		[]byte{0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1, 0xFE},
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+		[]byte{0xC3, 0x9E, 0x07, 0x2D, 0x9F, 0xAC, 0x63, 0x1D}},
+	CryptTest{
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
+		[]byte{0x01, 0x49, 0x33, 0xE0, 0xCD, 0xAF, 0xF6, 0xE4}},
+	CryptTest{
+		[]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0xF2, 0x1E, 0x9A, 0x77, 0xB7, 0x1C, 0x49, 0xBC}},
+	CryptTest{
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		[]byte{0x24, 0x59, 0x46, 0x88, 0x57, 0x54, 0x36, 0x9A}},
+	CryptTest{
+		[]byte{0xFE, 0xDC, 0xBA, 0x98, 0x76, 0x54, 0x32, 0x10},
+		[]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
+		[]byte{0x6B, 0x5C, 0x5A, 0x9C, 0x5D, 0x9E, 0x0A, 0x5A}},
+}
+
+func TestCipherEncrypt(t *testing.T) {
+	for i, tt := range encryptTests {
+		c, err := NewCipher(tt.key)
+		if err != nil {
+			t.Errorf("NewCipher(%d bytes) = %s", len(tt.key), err)
+			continue
+		}
+		ct := make([]byte, len(tt.out))
+		c.Encrypt(tt.in, ct)
+		for j, v := range ct {
+			if v != tt.out[j] {
+				t.Errorf("Cipher.Encrypt, test vector #%d: cipher-text[%d] = %#x, expected %#x", i, j, v, tt.out[j])
+				break
+			}
+		}
+	}
+}
+
+func TestCipherDecrypt(t *testing.T) {
+	for i, tt := range encryptTests {
+		c, err := NewCipher(tt.key)
+		if err != nil {
+			t.Errorf("NewCipher(%d bytes) = %s", len(tt.key), err)
+			continue
+		}
+		pt := make([]byte, len(tt.in))
+		c.Decrypt(tt.out, pt)
+		for j, v := range pt {
+			if v != tt.in[j] {
+				t.Errorf("Cipher.Decrypt, test vector #%d: plain-text[%d] = %#x, expected %#x", i, j, v, tt.in[j])
+				break
+			}
+		}
+	}
+}

src/pkg/crypto/blowfish/cipher.go

+// Copyright 2010 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.
+
+// This package implements Bruce Schneier's Blowfish encryption algorithm.
+package blowfish
+
+// The code is a port of Bruce Schneier's C implementation.
+// See http://www.schneier.com/blowfish.html.
+
+import (
+	"os"
+	"strconv"
+)
+
+// The Blowfish block size in bytes.
+const BlockSize = 8
+
+// A Cipher is an instance of Blowfish encryption using a particular key.
+type Cipher struct {
+	p              [18]uint32
+	s0, s1, s2, s3 [256]uint32
+}
+
+type KeySizeError int
+
+func (k KeySizeError) String() string {
+	return "crypto/blowfish: invalid key size " + strconv.Itoa(int(k))
+}
+
+// NewCipher creates and returns a Cipher.
+// The key argument should be the Blowfish key, 4 to 56 bytes.
+func NewCipher(key []byte) (*Cipher, os.Error) {
+	k := len(key)
+	if k < 4 || k > 56 {
+		return nil, KeySizeError(k)
+	}
+	var result Cipher
+	expandKey(key, &result)
+	return &result, nil
+}
+
+// BlockSize returns the Blowfish block size, 8 bytes.
+// It is necessary to satisfy the Cipher interface in the
+// package "crypto/block".
+func (c *Cipher) BlockSize() int { return BlockSize }
+
+// Encrypt encrypts the 8-byte buffer src using the key k
+// and stores the result in dst.
+// Note that for amounts of data larger than a block,
+// it is not safe to just call Encrypt on successive blocks;
+// instead, use an encryption mode like CBC (see crypto/block/cbc.go).
+func (c *Cipher) Encrypt(src, dst []byte) {
+	l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
+	r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
+	l, r = encryptBlock(l, r, c)
+	dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
+	dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
+}
+
+// Decrypt decrypts the 8-byte buffer src using the key k
+// and stores the result in dst.
+func (c *Cipher) Decrypt(src, dst []byte) {
+	l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
+	r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
+	l, r = decryptBlock(l, r, c)
+	dst[0], dst[1], dst[2], dst[3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
+	dst[4], dst[5], dst[6], dst[7] = byte(r>>24), byte(r>>16), byte(r>>8), byte(r)
+}
+
+// Reset zeros the key data, so that it will no longer
+// appear in the process's memory.
+func (c *Cipher) Reset() {
+	zero(&c.p)
+	zero(&c.s0)
+	zero(&c.s1)
+	zero(&c.s2)
+	zero(&c.s3)
+}