aes

aes.mode.go

package main

import (
	"fmt"
	"crypto/aes"
	"crypto/cipher"
	"encoding/hex"
	"path/filepath"
	"io/ioutil"
	"os"
)

func PKCS7Padding(b []byte) []byte {
	if extra := len(b)%aes.BlockSize; extra != 0 {
		padNum := aes.BlockSize - extra
		bitCode := byte(padNum)
		for i := 0; i < padNum; i++ {
			b = append(b, bitCode)
		}
	}
	return b
}

func cryp(dstf, srcf string, mode cipher.BlockMode) (err error) {

	src, err := os.Open(srcf)
	if err != nil {
		return
	}
	defer src.Close()

	b, err := ioutil.ReadAll(src)
	if err != nil {
		return
	}

	b = PKCS7Padding(b)

	out := make([]byte, len(b))
	mode.CryptBlocks(out, b)

	err = ioutil.WriteFile(dstf, out, 0600)

	return
}

var (
	key = []byte("examplekey123456")
	inDir = "test/"
	outDir = "prefix/"
	dDir = "deprefix/"
)

func crpytDir(path, desDir string, mode cipher.BlockMode) {
	err := filepath.Walk(path, func(fpath string, info os.FileInfo, err error) error {
		if info == nil {
			return err
		}
		if info.IsDir() {
			return nil
		}
		fmt.Println(fpath)
		return cryp(desDir+info.Name(), fpath, mode)
	})

	if err != nil {
		fmt.Println(err)
	}
}

func main() {

	block, err := aes.NewCipher(key)
	if err != nil {
		fmt.Println(err)
		return
	}
	var iv [aes.BlockSize]byte
	_, err = hex.Decode(iv[:], []byte("cfd80d18b1a842871608f71d8d37710f"))
	if err != nil {
		fmt.Println(err)
		return
	}

	mode := cipher.NewCBCEncrypter(block, iv[:])
	crpytDir(inDir, outDir, mode)

	mode = cipher.NewCBCDecrypter(block, iv[:])
	crpytDir(outDir, dDir, mode)
}