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