init

at-common/des/des.go

@@ -0,0 +1,81 @@
+package des
+
+import (
+	utils "anytunnel/at-common"
+	"bytes"
+	"crypto/des"
+	"encoding/hex"
+	"errors"
+)
+
+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)]
+}
+
+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 Encrypt(src []byte, key string) (string, error) {
+	block, err := des.NewCipher([]byte(utils.Md5(key)[0:8]))
+	if err != nil {
+		return "", err
+	}
+	bs := block.BlockSize()
+	src = ZeroPadding(src, bs)
+	// src = PKCS5Padding(src, bs)
+	if len(src)%bs != 0 {
+		return "", errors.New("Need a multiple of the blocksize")
+	}
+	out := make([]byte, len(src))
+	dst := out
+	for len(src) > 0 {
+		block.Encrypt(dst, src[:bs])
+		src = src[bs:]
+		dst = dst[bs:]
+	}
+	return hex.EncodeToString(out), nil
+}
+
+func Decrypt(_src string, _key string) ([]byte, error) {
+	key := []byte(utils.Md5(_key)[0:8])
+	src, err := hex.DecodeString(_src)
+	if err != nil {
+		return nil, err
+	}
+	block, err := des.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]byte, len(src))
+	dst := out
+	bs := block.BlockSize()
+	if len(src)%bs != 0 {
+		return nil, errors.New("crypto/cipher: input not full blocks")
+	}
+	for len(src) > 0 {
+		block.Decrypt(dst, src[:bs])
+		src = src[bs:]
+		dst = dst[bs:]
+	}
+	out = ZeroUnPadding(out)
+	// out = PKCS5UnPadding(out)
+	return out, nil
+}