content: /*
   * Copyright 1999-2021 Alibaba Group Holding Ltd.
   *
   * 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 com.alibaba.nacos.client.auth.ram.utils;
  
  import com.alibaba.nacos.common.codec.Base64;
  
  import javax.crypto.Mac;
  import javax.crypto.spec.SecretKeySpec;
  import java.nio.charset.Charset;
  import java.nio.charset.StandardCharsets;
  
  /**
   * Sign util.
   *
   * @author pbting
   * @date 2019-01-22 10:20 PM
   */
  public class SignUtil {
      
      private static final Charset UTF8 = StandardCharsets.UTF_8;
      
      /**
       * Sign.
       *
       * @param data data
       * @param key  key
       * @return signature
       * @throws Exception exception
       */
      public static String sign(String data, String key) throws Exception {
          try {
              byte[] signature = sign(data.getBytes(UTF8), key.getBytes(UTF8), SignUtil.SigningAlgorithm.HmacSHA1);
              return new String(Base64.encodeBase64(signature));
          } catch (Exception ex) {
              throw new Exception("Unable to calculate a request signature: " + ex.getMessage(), ex);
          }
      }
      
      static byte[] sign(byte[] data, byte[] key, SignUtil.SigningAlgorithm algorithm) throws Exception {
          try {
              Mac mac = Mac.getInstance(algorithm.toString());
              mac.init(new SecretKeySpec(key, algorithm.toString()));
              return mac.doFinal(data);
          } catch (Exception ex) {
              throw new Exception("Unable to calculate a request signature: " + ex.getMessage(), ex);
          }
      }
      
      public enum SigningAlgorithm {
          // Hmac SHA1 algorithm
          HmacSHA1;
          
          SigningAlgorithm() {
          }
      }
  }
  