时代新秀golang--golang加密算法之DES

//des_ecb_pkcs5padding.go
package main
import (
 "bytes"
 "crypto/des"
 "encoding/base64"
 "errors"
)
//明文补码算法
func PKCS5Padding(ciphertext []byte, blockSize int) []byte {
 padding := blockSize - len(ciphertext) % blockSize
 padtext := bytes.Repeat([]byte{byte(padding)}, padding)
 return append(ciphertext, padtext...)
}
//明文减码算法
func PKCS5UnPadding(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)
 return append(ciphertext, padtext...)
}
func ZeroUnPadding(origData []byte) []byte {
 return bytes.TrimFunc(origData,
 func(r rune) bool {
 return r == rune(0)
        })
}
func DesEncrypt(src, key []byte) ([]byte, error) {
 block, err := des.NewCipher(key)
 if err != nil {
 return nil, err
    }
 bs := block.BlockSize()
 //对明文数据进行补码
 src = PKCS5Padding(src, bs)
 if len(src) % bs != 0 {
 return nil, errors.New("Need a multiple of the blocksize")
    }
 out := make([]byte, len(src))
 dst := out
 //对明文按照blocksize进行分块加密
 //必要时可以使用go关键字进行并行加密
 for len(src) > 0 {
        block.Encrypt(dst, src[:bs])
 src = src[bs:]
 dst = dst[bs:]
    }
 dstBase64 := make([]byte, base64.StdEncoding.EncodedLen(len(out)))
    base64.StdEncoding.Encode(dstBase64, out)
 return dstBase64, nil
}
func DesDecrypt(src, key []byte) ([]byte, error) {
 srcBase64 := make([]byte, base64.StdEncoding.DecodedLen(len(src)))
 n, err := base64.StdEncoding.Decode(srcBase64, src)
 if err != nil {
 return nil, err
    }
 srcUnBase64 := srcBase64[:n]
 block, err := des.NewCipher(key)
 if err != nil {
 return nil, err
    }
 out := make([]byte, len(srcUnBase64))
 dst := out
 bs := block.BlockSize()
 if len(srcUnBase64) % bs != 0 {
 return nil, errors.New("crypto/cipher: input not full blocks")
    }
 for len(srcUnBase64) > 0 {
        block.Decrypt(dst, srcUnBase64[:bs])
 srcUnBase64 = srcUnBase64[bs:]
 dst = dst[bs:]
    }
 out = PKCS5UnPadding(out)
 return out, nil
}
//main.go 使用DES算法来加密电话号码
package main
import (
 "bufio"
 "flag"
 "fmt"
 "io"
 "os"
 "runtime"
 "sync"
)
const (
 GPNUM = 1000
 //key只能是8位,不能少于8位也不能多于8位.
 KEY = "ImDesKey"
)
var (
 inputFile, outputFile string
)
type outputWriter struct {
    file *os.File
    fWriter *bufio.Writer
    rwMutex *sync.RWMutex
ch chan []byte 
wg *sync.WaitGroup
}
func (ow *outputWriter) Write(row []byte) {
    ow.rwMutex.Lock()
    ow.fWriter.Write(row)
    ow.rwMutex.Unlock()
}
func (ow *outputWriter) Flush() {
    ow.rwMutex.Lock()
    ow.fWriter.Flush()
    ow.rwMutex.Unlock()
}
func (ow *outputWriter) Close() {
    ow.file.Close()
}
func NewOutputWriter(dstFile string, gp int) (*outputWriter, error) {
 f, err := os.OpenFile(dstFile,os.O_WRONLY|os.O_CREATE|os.O_TRUNC,0644)
 if err != nil {
 return nil, err
    }
 w := bufio.NewWriter(f)
ch := make(chan []byte, gp)
return &outputWriter{file:f, fWriter:w, rwMutex:&sync.RWMutex{}, ch:ch, wg:&sync.WaitGroup{}}, nil
}
func init() {
    runtime.GOMAXPROCS(runtime.NumCPU())
    flag.StringVar(&inputFile, "srcfile", "tel.txt", "src file")
    flag.StringVar(&outputFile, "dstfile", "tel_en.txt", "dst file")
    flag.Parse()
}
func concurrentProcess(gp int, src string) {
 //ch := make(chan []byte, gp)
//wg := &sync.WaitGroup{}
 fReader, err := os.Open(src)
 if err != nil {
        fmt.Errorf("Error: %v\n", err)
        os.Exit(1)
    }
 //defer fReader.Close()
 reader := bufio.NewReader(fReader)
 writer, err := NewOutputWriter(outputFile, gp)
 if err != nil {
        fmt.Errorf("Error: %v\n", err)
    }
//defer writer.Close()
 for {
lineBytes, _, err := reader.ReadLine()
 if err == io.EOF {
 break
}
 //tab键的ascii码为9
 //lineBytesSlice := bytes.Split(lineBytes, []byte{9})
 //telBytes := lineBytesSlice[0]
 //provBytes := lineBytesSlice[1]
 //cityBytes := lineBytesSlice[2]
        writer.wg.Add(1)
 go func(ch chan []byte) {
lineWriteBytes := make([]byte,0,45)
telBytes := make([]byte,0,11)
for i:=0;i<=10;i++{
telBytes = append(telBytes, lineBytes[i])
}
//注意：这里不能使用telEnBytes, telEnErr := DesEncrypt(lineBytes[:11], []byte(KEY))来加密电话号码，否则会修改lineBytes[11:]中的内容
telEnBytes, telEnErr := DesEncrypt(telBytes, []byte(KEY))
 if telEnErr != nil {
                fmt.Errorf("Error: %v\n", telEnErr)
 //os.Exit(1)
            }
for i:=0;i<=11;i++ {
lineWriteBytes = append(lineWriteBytes,lineBytes[i])
}
for i:=0;i<=23;i++{
lineWriteBytes = append(lineWriteBytes, telEnBytes[i])
}
for i:=11;i<len(lineBytes);i++{
lineWriteBytes = append(lineWriteBytes, lineBytes[i])
}
//换行的ascii码为10lineBytes[:11]
lineWriteBytes = append(lineWriteBytes,10)
 //writer.Write(lineWriteBytes)
 //writer.Flush()
ch <- lineWriteBytes
 defer writer.wg.Done()
        }(writer.ch)
writer.wg.Add(1)
go func(ch chan []byte) {
writer.Write(<-ch)
writer.Flush()
defer writer.wg.Done()
}(writer.ch)
    }
 //writer.Flush()
    writer.wg.Wait()
    fReader.Close()
writer.Close()
}
func main() {
 concurrentProcess(GPNUM, inputFile)
}
//tel.txt 电话号码文件
13615660000    551    0566 
13665660000    551    0566
13615580000    551    0566
13615670000    551    0566
13615680000    551    0566
13615510000    551    0566
13615600000    551    0566
13615690000    551    0566
13645640000    551    0566
13665540000    551    0566