77 lines
1.7 KiB
Go
77 lines
1.7 KiB
Go
|
// Copyright 2013 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.
|
||
|
|
|
||
|
|
// Electronic Code Book (ECB) mode.
|
||
|
|
|
||
|
|
// ECB provides confidentiality by assigning a fixed ciphertext block to each
|
||
|
|
// plaintext block.
|
||
|
|
|
||
|
|
// See NIST SP 800-38A, pp 08-09
|
||
|
|
|
||
|
|
package cipher
|
||
|
|
|
||
|
|
import (
|
||
|
|
"crypto/cipher"
|
||
|
|
)
|
||
|
|
|
||
|
|
type ecb struct {
|
||
|
|
b cipher.Block
|
||
|
|
blockSize int
|
||
|
|
}
|
||
|
|
|
||
|
|
func newECB(b cipher.Block) *ecb {
|
||
|
|
return &ecb{
|
||
|
|
b: b,
|
||
|
|
blockSize: b.BlockSize(),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
type ecbEncrypter ecb
|
||
|
|
|
||
|
|
// NewECBEncrypter returns a BlockMode which encrypts in electronic code book
|
||
|
|
// mode, using the given Block.
|
||
|
|
func NewECBEncrypter(b cipher.Block) cipher.BlockMode {
|
||
|
|
return (*ecbEncrypter)(newECB(b))
|
||
|
|
}
|
||
|
|
|
||
|
|
func (x *ecbEncrypter) BlockSize() int { return x.blockSize }
|
||
|
|
|
||
|
|
func (x *ecbEncrypter) CryptBlocks(dst, src []byte) {
|
||
|
|
if len(src)%x.blockSize != 0 {
|
||
|
|
panic("crypto/cipher: input not full blocks")
|
||
|
|
}
|
||
|
|
if len(dst) < len(src) {
|
||
|
|
panic("crypto/cipher: output smaller than input")
|
||
|
|
}
|
||
|
|
for len(src) > 0 {
|
||
|
|
x.b.Encrypt(dst, src[:x.blockSize])
|
||
|
|
src = src[x.blockSize:]
|
||
|
|
dst = dst[x.blockSize:]
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
type ecbDecrypter ecb
|
||
|
|
|
||
|
|
// NewECBDecrypter returns a BlockMode which decrypts in electronic code book
|
||
|
|
// mode, using the given Block.
|
||
|
|
func NewECBDecrypter(b cipher.Block) cipher.BlockMode {
|
||
|
|
return (*ecbDecrypter)(newECB(b))
|
||
|
|
}
|
||
|
|
|
||
|
|
func (x *ecbDecrypter) BlockSize() int { return x.blockSize }
|
||
|
|
|
||
|
|
func (x *ecbDecrypter) CryptBlocks(dst, src []byte) {
|
||
|
|
if len(src)%x.blockSize != 0 {
|
||
|
|
panic("crypto/cipher: input not full blocks")
|
||
|
|
}
|
||
|
|
if len(dst) < len(src) {
|
||
|
|
panic("crypto/cipher: output smaller than input")
|
||
|
|
}
|
||
|
|
for len(src) > 0 {
|
||
|
|
x.b.Decrypt(dst, src[:x.blockSize])
|
||
|
|
src = src[x.blockSize:]
|
||
|
|
dst = dst[x.blockSize:]
|
||
|
|
}
|
||
|
|
}
|