结构调整、kcp支持

lib/crypt/crypt.go

@@ -0,0 +1,80 @@
+package crypt
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/md5"
+	"encoding/hex"
+	"errors"
+	"math/rand"
+	"time"
+)
+
+//en
+func AesEncrypt(origData, key []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	blockSize := block.BlockSize()
+	origData = PKCS5Padding(origData, blockSize)
+	// origData = ZeroPadding(origData, block.BlockSize())
+	blockMode := cipher.NewCBCEncrypter(block, key[:blockSize])
+	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
+}
+
+//de
+func AesDecrypt(crypted, key []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	blockSize := block.BlockSize()
+	blockMode := cipher.NewCBCDecrypter(block, key[:blockSize])
+	origData := make([]byte, len(crypted))
+	blockMode.CryptBlocks(origData, crypted)
+	err, origData = PKCS5UnPadding(origData)
+	return origData, err
+}
+
+//Completion when the length is insufficient
+func PKCS5Padding(ciphertext []byte, blockSize int) []byte {
+	padding := blockSize - len(ciphertext)%blockSize
+	padtext := bytes.Repeat([]byte{byte(padding)}, padding)
+	return append(ciphertext, padtext...)
+}
+
+//Remove excess
+func PKCS5UnPadding(origData []byte) (error, []byte) {
+	length := len(origData)
+	// 去掉最后一个字节 unpadding 次
+	unpadding := int(origData[length-1])
+	if (length - unpadding) < 0 {
+		return errors.New("len error"), nil
+	}
+	return nil, origData[:(length - unpadding)]
+}
+
+//Generate 32-bit MD5 strings
+func Md5(s string) string {
+	h := md5.New()
+	h.Write([]byte(s))
+	return hex.EncodeToString(h.Sum(nil))
+}
+
+//Generating Random Verification Key
+func GetRandomString(l int) string {
+	str := "0123456789abcdefghijklmnopqrstuvwxyz"
+	bytes := []byte(str)
+	result := []byte{}
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	for i := 0; i < l; i++ {
+		result = append(result, bytes[r.Intn(len(bytes))])
+	}
+	return string(result)
+}