mirror of
https://gitee.com/johng/gf.git
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79 lines
2.3 KiB
Go
79 lines
2.3 KiB
Go
// Copyright 2017 gf Author(https://gitee.com/johng/gf). All Rights Reserved.
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//
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// This Source Code Form is subject to the terms of the MIT License.
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// If a copy of the MIT was not distributed with this file,
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// You can obtain one at https://gitee.com/johng/gf.
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// Package gaes provides useful API for AES encryption/decryption algorithms.
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package gaes
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import (
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"bytes"
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"errors"
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"crypto/aes"
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"crypto/cipher"
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)
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const (
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ivDefValue = "I Love Go Frame!"
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)
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// AES加密, 使用CBC模式，注意key必须为16/24/32位长度，iv初始化向量为非必需参数
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func Encrypt(plainText []byte, key []byte, iv...[]byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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blockSize := block.BlockSize()
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plainText = PKCS5Padding(plainText, blockSize)
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ivValue := ([]byte)(nil)
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if len(iv) > 0 {
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ivValue = iv[0]
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} else {
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ivValue = []byte(ivDefValue)
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}
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blockMode := cipher.NewCBCEncrypter(block, ivValue)
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ciphertext := make([]byte, len(plainText))
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blockMode.CryptBlocks(ciphertext, plainText)
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return ciphertext, nil
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}
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// AES解密, 使用CBC模式，注意key必须为16/24/32位长度，iv初始化向量为非必需参数
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func Decrypt(cipherText []byte, key []byte, iv...[]byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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blockSize := block.BlockSize()
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if len(cipherText) < blockSize {
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return nil, errors.New("cipherText too short")
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}
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ivValue := ([]byte)(nil)
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if len(iv) > 0 {
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ivValue = iv[0]
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} else {
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ivValue = []byte(ivDefValue)
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}
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if len(cipherText)%blockSize != 0 {
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return nil, errors.New("cipherText is not a multiple of the block size")
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}
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blockModel := cipher.NewCBCDecrypter(block, ivValue)
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plainText := make([]byte, len(cipherText))
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blockModel.CryptBlocks(plainText, cipherText)
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plainText = PKCS5UnPadding(plainText)
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return plainText, nil
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}
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func PKCS5Padding(src []byte, blockSize int) []byte {
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padding := blockSize - len(src)%blockSize
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padtext := bytes.Repeat([]byte{byte(padding)}, padding)
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return append(src, padtext...)
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}
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func PKCS5UnPadding(src []byte) []byte {
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length := len(src)
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unpadding := int(src[length - 1])
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return src[:(length - unpadding)]
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} |