go.crypto: initial code
Manual edits to README.
Moved from main Go repository, deleted Makefiles, ran gofix -r go1rename.
Tested with: go test code.google.com/p/go.crypto/...
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5564059
diff --git a/blowfish/cipher.go b/blowfish/cipher.go
new file mode 100644
index 0000000..94e10f0
--- /dev/null
+++ b/blowfish/cipher.go
@@ -0,0 +1,100 @@
+// 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 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 "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) Error() 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, error) {
+ var result Cipher
+ k := len(key)
+ if k < 4 || k > 56 {
+ return nil, KeySizeError(k)
+ }
+ initCipher(key, &result)
+ ExpandKey(key, &result)
+ return &result, nil
+}
+
+// NewSaltedCipher creates a returns a Cipher that folds a salt into its key
+// schedule. For most purposes, NewCipher, instead of NewSaltedCipher, is
+// sufficient and desirable. For bcrypt compatiblity, the key can be over 56
+// bytes.
+func NewSaltedCipher(key, salt []byte) (*Cipher, error) {
+ var result Cipher
+ k := len(key)
+ if k < 4 {
+ return nil, KeySizeError(k)
+ }
+ initCipher(key, &result)
+ expandKeyWithSalt(key, salt, &result)
+ return &result, nil
+}
+
+// BlockSize returns the Blowfish block size, 8 bytes.
+// It is necessary to satisfy the Block interface in the
+// package "crypto/cipher".
+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/cipher/cbc.go).
+func (c *Cipher) Encrypt(dst, src []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(dst, src []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[0:])
+ zero(c.s0[0:])
+ zero(c.s1[0:])
+ zero(c.s2[0:])
+ zero(c.s3[0:])
+}
+
+func initCipher(key []byte, c *Cipher) {
+ copy(c.p[0:], p[0:])
+ copy(c.s0[0:], s0[0:])
+ copy(c.s1[0:], s1[0:])
+ copy(c.s2[0:], s2[0:])
+ copy(c.s3[0:], s3[0:])
+}
