golang AES128 ECB加密_Golang

AES128 ECB

func EcbDecrypt(data, key []byte) []byte {
	block, _ := aes.NewCipher(key)
	decrypted := make([]byte, len(data))
	size := block.BlockSize()

	for bs, be := 0, size; bs < len(data); bs, be = bs+size, be+size {
		block.Decrypt(decrypted[bs:be], data[bs:be])
	}

	return PKCS5UnPadding(decrypted)
}

func EcbEncrypt(data, key []byte) []byte {
	block, _ := aes.NewCipher(key)
	data = PKCS5Padding(data, block.BlockSize())
	decrypted := make([]byte, len(data))
	size := block.BlockSize()

	for bs, be := 0, size; bs < len(data); bs, be = bs+size, be+size {
		block.Encrypt(decrypted[bs:be], data[bs:be])
	}

	return decrypted
}
func PKCS5Padding(ciphertext []byte, blockSize int) []byte {
	padding := blockSize - len(ciphertext)%blockSize
	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(ciphertext, padtext...)
}

func PKCS5UnPadding(origData []byte) []byte {
	length := len(origData)
	// 去掉最后一个字节 unpadding 次
	unpadding := int(origData[length-1])
	return origData[:(length - unpadding)]
}

补码方式除了pkcs5还有

func PKCS7Padding(ciphertext []byte, blocksize int) []byte {
	padding := blocksize - len(ciphertext)%blocksize
	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
	return append(ciphertext, padtext...)
}

//去码
func PKCS7UnPadding(origData []byte) []byte {
	length := len(origData)
	unpadding := int(origData[length-1])
	return origData[:(length - unpadding)]
}

func ZeroPadding(ciphertext []byte, blockSize int) []byte {
	padding := blockSize - len(ciphertext)%blockSize
	padtext := bytes.Repeat([]byte{0}, padding) //用0去填充
	return append(ciphertext, padtext...)
}

func ZeroUnPadding(origData []byte) []byte {
	return bytes.TrimFunc(origData,
		func(r rune) bool {
			return r == rune(0)
		})
}

AES128 CBC

func AesEncryptCBC(origData []byte, key []byte,iv []byte) (encrypted []byte) {
	// 分组秘钥
	// NewCipher该函数限制了输入k的长度必须为16, 24或者32
	block, _ := aes.NewCipher(key)
	blockSize := block.BlockSize()
	origData = ZeroPadding(origData, blockSize)
	blockMode := cipher.NewCBCEncrypter(block, iv)
	encrypted = make([]byte, len(origData))
	blockMode.CryptBlocks(encrypted, origData)
	return encrypted
}
func AesDecryptCBC(encrypted []byte, key []byte,iv []byte) (decrypted []byte) {
	block, _ := aes.NewCipher(key)
	//blockSize := block.BlockSize()
	blockMode := cipher.NewCBCDecrypter(block, iv)
	decrypted = make([]byte, len(encrypted))
	blockMode.CryptBlocks(decrypted, encrypted)
	decrypted = ZeroUnPadding(decrypted)
	return decrypted
}

func ZeroPadding(ciphertext []byte, blockSize int) []byte {
	padding := blockSize - len(ciphertext)%blockSize
	padtext := bytes.Repeat([]byte{0}, padding) //用0去填充
	return append(ciphertext, padtext...)
}

func ZeroUnPadding(origData []byte) []byte {
	return bytes.TrimFunc(origData,
		func(r rune) bool {
			return r == rune(0)
		})
}

CFB 略

	block, err := aes.NewCipher(key)
	if err != nil {
		panic(err)
	}

	// The IV needs to be unique, but not secure. Therefore it's common to
	// include it at the beginning of the ciphertext.
	if len(ciphertext) < aes.BlockSize {
		panic("ciphertext too short")
	}
	iv := ciphertext[:aes.BlockSize]
	ciphertext = ciphertext[aes.BlockSize:]

	stream := cipher.NewCFBDecrypter(block, iv)

	// XORKeyStream can work in-place if the two arguments are the same.
	stream.XORKeyStream(ciphertext, ciphertext)

block, err := aes.NewCipher(key)
	if err != nil {
		panic(err)
	}

	// The IV needs to be unique, but not secure. Therefore it's common to
	// include it at the beginning of the ciphertext.
	ciphertext := make([]byte, aes.BlockSize+len(plaintext))
	iv := ciphertext[:aes.BlockSize]
	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
		panic(err)
	}

	stream := cipher.NewCFBEncrypter(block, iv)
	stream.XORKeyStream(ciphertext[aes.BlockSize:], plaintext)