小花狸監控之加密

小花狸監控
採用對稱加密演算法AES
明文首先經過Base64編碼,然後用空格填充到指定位數,使用AES加密,最後將加密的資料再用Base64編碼

$GOPATH/probe/module/AES.go

package module

import (
   "crypto/aes"
   "crypto/cipher"
   "crypto/rand"
   "encoding/base64"
   "encoding/hex"
   "errors"
   "fmt"
   "io"
   "strings"
   "sync"
)

const (
   //aesTable是金鑰
   aesTable    = "abcdefghijklmnopkrstuvwsyz333333"
   base64Table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
)

var (
   block       cipher.Block
   mutex       sync.Mutex
   base64Coder = base64.NewEncoding(base64Table)
)

func EncryptString(src string) string {
   datastr := base64Coder.EncodeToString([]byte(src))
   for len(datastr)%aes.BlockSize != 0 {
       datastr = datastr + " "
   }
   data, _ := Encrypt([]byte(datastr))
   result := base64Coder.EncodeToString(data)
   return result
}

// AES加密
func Encrypt(src []byte) ([]byte, error) {
   // 驗證輸入引數
   // 必須為aes.Blocksize的倍數
   if len(src)%aes.BlockSize != 0 {
       return nil, errors.New("crypto/cipher: input not full blocks")
   }

   encryptText := make([]byte, aes.BlockSize+len(src))

   iv := encryptText[:aes.BlockSize]
   if _, err := io.ReadFull(rand.Reader, iv); err != nil {
       return nil, err
   }

   mode := cipher.NewCBCEncrypter(block, iv)

   mode.CryptBlocks(encryptText[aes.BlockSize:], src)

   return encryptText, nil
}

func DecryptString(src string) string {
   var result []byte
   data, _ := base64Coder.DecodeString(src)
   data, _ = Decrypt(data)
   datastr := strings.Trim(string(data), " ")
   result, _ = base64Coder.DecodeString(datastr)
   return string(result)
}

// AES解密
func Decrypt(src []byte) ([]byte, error) {
   // hex
   decryptText, err := hex.DecodeString(fmt.Sprintf("%x", string(src)))
   if err != nil {
       return nil, err
   }

   // 長度不能小於aes.Blocksize
   if len(decryptText) < aes.BlockSize {
       return nil, errors.New("crypto/cipher: ciphertext too short")
   }

   iv := decryptText[:aes.BlockSize]
   decryptText = decryptText[aes.BlockSize:]

   // 驗證輸入引數
   // 必須為aes.Blocksize的倍數
   if len(decryptText)%aes.BlockSize != 0 {
       return nil, errors.New("crypto/cipher: ciphertext is not a multiple of the block size")
   }

   mode := cipher.NewCBCDecrypter(block, iv)

   mode.CryptBlocks(decryptText, decryptText)

   return decryptText, nil
}

func init() {
   mutex.Lock()
   defer mutex.Unlock()

   if block != nil {
       return
   }

   cblock, err := aes.NewCipher([]byte(aesTable))
   if err != nil {
       panic("aes.NewCipher: " + err.Error())
   }

   block = cblock
}

呼叫程式
$GOPATH/main.go

package main

import (
        "fmt"
        "probe/module"
)

func main() {
        data := "zbcdfe"
        fmt.Println("明文:", data)
        s := module.EncryptString(data)
        fmt.Println("密文:", s)
        fmt.Println("解密:", module.DecryptString(s))
}
~
結果:

參考:
http://www.oschina.net/code/snippet_197499_25891

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/29254281/viewspace-1477252/，如需轉載，請註明出處，否則將追究法律責任。

小花狸監控之加密

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