verify req key

pkg/common/mw/check.go

@@ -0,0 +1,65 @@
+package mw
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/md5"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"github.com/OpenIMSDK/Open-IM-Server/pkg/common/config"
+	"math/rand"
+	"strings"
+	"sync"
+	"time"
+)
+
+var (
+	block cipher.Block
+	once  sync.Once
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+func initAesKey() {
+	once.Do(func() {
+		key := md5.Sum([]byte("openim:" + config.Config.Secret))
+		var err error
+		block, err = aes.NewCipher(key[:])
+		if err != nil {
+			panic(err)
+		}
+	})
+}
+
+func genReqKey(args []string) string {
+	initAesKey()
+	plaintext := md5.Sum([]byte(strings.Join(args, ":")))
+	var iv = make([]byte, aes.BlockSize, aes.BlockSize+md5.Size)
+	if _, err := rand.Read(iv); err != nil {
+		panic(err)
+	}
+	ciphertext := make([]byte, md5.Size)
+	cipher.NewCBCEncrypter(block, iv).CryptBlocks(ciphertext, plaintext[:])
+	return base64.StdEncoding.EncodeToString(append(iv, ciphertext...))
+}
+
+func verifyReqKey(args []string, key string) error {
+	initAesKey()
+	k, err := base64.StdEncoding.DecodeString(key)
+	if err != nil {
+		return fmt.Errorf("invalid key %v", err)
+	}
+	if len(k) != aes.BlockSize+md5.Size {
+		return errors.New("invalid key")
+	}
+	plaintext := make([]byte, md5.Size)
+	cipher.NewCBCDecrypter(block, k[:aes.BlockSize]).CryptBlocks(plaintext, k[aes.BlockSize:])
+	sum := md5.Sum([]byte(strings.Join(args, ":")))
+	if string(plaintext) != string(sum[:]) {
+		return errors.New("mismatch key")
+	}
+	return nil
+}