98 lines
2.2 KiB
Go
98 lines
2.2 KiB
Go
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/*
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* @Date: 2021-03-11 17:25:13
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* @LastEditors: viletyy
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* @LastEditTime: 2021-04-26 23:17:26
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* @FilePath: /yolk/crypt/des.go
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*/
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package crypt
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import (
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"bytes"
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"crypto/des"
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"encoding/hex"
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"errors"
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)
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/*
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* DES是一种对称加密算法,又称为美国数据加密标准.DES加密时以64位分组对数据进行加密,加密和解密都使用的是同一个长度为64位的密钥,
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* 实际上只用到了其中的56位,密钥中的第8,16…64位用来作奇偶校验.DES有ECB（电子密码本）和CBC（加密块）等加密模式. DES算法的安
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* 全性很高,目前除了穷举搜索破解外, 尚无更好的的办法来破解.其密钥长度越长,破解难度就越大. 填充和去填充函数.
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*/
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var desKey = []byte("2fa6c1e9")
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type DesCrypt struct {
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Key []byte
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}
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func NewDesCrypt(key ...[]byte) *DesCrypt {
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if len(key) > 0 {
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desKey = key[0]
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}
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return &DesCrypt{
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Key: desKey,
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}
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}
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// Des加密
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func (crypt *DesCrypt) Encrypt(text string) (string, error) {
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src := []byte(text)
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block, err := des.NewCipher(crypt.Key)
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if err != nil {
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return "", err
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}
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bs := block.BlockSize()
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src = ZeroPadding(src, bs)
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if len(src)%bs != 0 {
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return "", errors.New("Need a multiple of the blocksize")
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}
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out := make([]byte, len(src))
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dst := out
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for len(src) > 0 {
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block.Encrypt(dst, src[:bs])
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src = src[bs:]
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dst = dst[bs:]
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}
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return hex.EncodeToString(out), nil
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}
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// Des解密
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func (crypt *DesCrypt) Decrypt(decrypted string) (string, error) {
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src, err := hex.DecodeString(decrypted)
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if err != nil {
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return "", err
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}
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block, err := des.NewCipher(crypt.Key)
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if err != nil {
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return "", err
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}
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out := make([]byte, len(src))
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dst := out
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bs := block.BlockSize()
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if len(src)%bs != 0 {
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return "", errors.New("crypto/cipher: input not full blocks")
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}
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for len(src) > 0 {
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block.Decrypt(dst, src[:bs])
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src = src[bs:]
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dst = dst[bs:]
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}
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out = ZeroUnPadding(out)
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return string(out), nil
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}
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func ZeroPadding(ciphertext []byte, blockSize int) []byte {
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padding := blockSize - len(ciphertext)%blockSize
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padtext := bytes.Repeat([]byte{0}, padding)
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return append(ciphertext, padtext...)
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}
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func ZeroUnPadding(origData []byte) []byte {
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return bytes.TrimFunc(origData,
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func(r rune) bool {
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return r == rune(0)
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})
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}
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