92 lines
3.0 KiB
Go
92 lines
3.0 KiB
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 implements Bruce Schneier's Blowfish encryption algorithm.
|
|
package blowfish // import "golang.org/x/crypto/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, from 1 to 56 bytes.
|
|
func NewCipher(key []byte) (*Cipher, error) {
|
|
var result Cipher
|
|
if k := len(key); k < 1 || k > 56 {
|
|
return nil, KeySizeError(k)
|
|
}
|
|
initCipher(&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) {
|
|
if len(salt) == 0 {
|
|
return NewCipher(key)
|
|
}
|
|
var result Cipher
|
|
if k := len(key); k < 1 {
|
|
return nil, KeySizeError(k)
|
|
}
|
|
initCipher(&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)
|
|
}
|
|
|
|
func initCipher(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:])
|
|
}
|