feat: add aliyun captcha (#833)

* feat: add aliyun captcha provider

* Rename App key

* fix typo

* Rename HMACSHA1 & Reused clientId2 and clientSecret2

* Update ProviderEditPage.js

* Delete unused import

Co-authored-by: Gucheng <85475922+nomeguy@users.noreply.github.com>

util/crypto.go

@@ -0,0 +1,30 @@
+// Copyright 2022 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package util
+
+import (
+	"crypto/hmac"
+	"crypto/sha1"
+	"encoding/base64"
+)
+
+func GetHmacSha1(keyStr, value string) string {
+	key := []byte(keyStr)
+	mac := hmac.New(sha1.New, key)
+	mac.Write([]byte(value))
+	res := base64.StdEncoding.EncodeToString(mac.Sum(nil))
+
+	return res
+}