golang DES加密解密

http://www.iteye.com/topic/1122076/

package main

import(
    "crypto/des"
    "crypto/cipher"
    "fmt"
    "bytes"
)

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)
    unpadding := int(origData[length-1])
    return origData[:(length - unpadding)]
}

// 3DES加密  key=3x8=24bit
func TripleDesEncrypt(origData, key []byte) ([]byte, error) {
     block, err := des.NewTripleDESCipher(key)
     if err != nil {
          return nil, err
     }
     origData = PKCS5Padding(origData, block.BlockSize())
     // origData = ZeroPadding(origData, block.BlockSize())
     blockMode := cipher.NewCBCEncrypter(block, key[:8])
     crypted := make([]byte, len(origData))
     blockMode.CryptBlocks(crypted, origData)
     return crypted, nil
}

// 3DES解密
func TripleDesDecrypt(crypted, key []byte) ([]byte, error) {
     block, err := des.NewTripleDESCipher(key)
     if err != nil {
          return nil, err
     }
     blockMode := cipher.NewCBCDecrypter(block, key[:8])
     origData := make([]byte, len(crypted))
     // origData := crypted
     blockMode.CryptBlocks(origData, crypted)
     origData = PKCS5UnPadding(origData)
     // origData = ZeroUnPadding(origData)
     return origData, nil
}

func DesEncrypt(origData, key []byte) ([]byte, error) {
    block, err := des.NewCipher(key)
    if err != nil {
        return nil, err
    }
    origData = PKCS5Padding(origData, block.BlockSize())
    // origData = ZeroPadding(origData, block.BlockSize())
    blockMode := cipher.NewCBCEncrypter(block, key)
    crypted := make([]byte, len(origData))
    // 根据CryptBlocks方法的说明，如下方式初始化crypted也可以
    // crypted := origData
    blockMode.CryptBlocks(crypted, origData)
    return crypted, nil
}

//des解密  key=8bit
func DesDecrypt(crypted, key []byte) ([]byte, error) {
    block, err := des.NewCipher(key)
    if err != nil {
        return nil, err
    }
    blockMode := cipher.NewCBCDecrypter(block, key)
    //origData := make([]byte, len(crypted))
    origData := crypted
    blockMode.CryptBlocks(origData, crypted)
    //origData = PKCS5UnPadding(origData)

    origData = PKCS5UnPadding(origData)
    return origData, nil
}

func main() {
    origData := "aaaaaaaaaaaaahejlwjeoioiuweroihihichy568yeiwehri"
    key := "12345678"
    crypted, err := DesEncrypt([]byte(origData), []byte(key))
    if err != nil {
        fmt.Println(err)
    }else{
        // fmt.Printf("crypted = %s\n", crypted)
        fmt.Printf("crypted = %X\n", crypted)
    }

    dedata, err1 := DesDecrypt([]byte(crypted), []byte(key))
    if err1 != nil {
        fmt.Println(err1)
    }else{
        // fmt.Printf("crypted = %s\n", crypted)
        fmt.Printf("dedata = %s\n", dedata)
    }

    key = "123456781234567812345678"
    crypted, err = TripleDesEncrypt([]byte(origData), []byte(key))
    if err != nil {
        fmt.Println(err)
    }else{
        // fmt.Printf("crypted = %s\n", crypted)
        fmt.Printf("crypted = %X\n", crypted)
    }

    dedata2, err2 := TripleDesDecrypt([]byte(crypted), []byte(key))
    if err2 != nil {
        fmt.Println(err2)
    }else{
        // fmt.Printf("crypted = %s\n", crypted)
        fmt.Printf("dedata2 = %s\n", dedata2)
    }
}