com.dahuatech.hutool.crypto.digest.mac.DefaultHMacEngine Maven / Gradle / Ivy

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package com.dahuatech.hutool.crypto.digest.mac;

import com.dahuatech.hutool.core.io.IoUtil;
import com.dahuatech.hutool.crypto.CryptoException;
import com.dahuatech.hutool.crypto.SecureUtil;

import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.io.InputStream;

/**
 * 默认的HMAC算法实现引擎，使用{@link Mac} 实现摘要

 * 当引入BouncyCastle库时自动使用其作为Provider
 *
 * @author Looly
 * @since 4.5.13
 */
public class DefaultHMacEngine implements MacEngine {

  private Mac mac;

  // -------------------------------------------------------------------------------------------
  // Constructor start
  /**
   * 构造
   *
   * @param algorithm 算法
   * @param key 密钥
   * @since 4.5.13
   */
  public DefaultHMacEngine(String algorithm, byte[] key) {
    init(algorithm, key);
  }

  /**
   * 构造
   *
   * @param algorithm 算法
   * @param key 密钥
   * @since 4.5.13
   */
  public DefaultHMacEngine(String algorithm, SecretKey key) {
    init(algorithm, key);
  }
  // -------------------------------------------------------------------------------------------
  // Constructor end

  /**
   * 初始化
   *
   * @param algorithm 算法
   * @param key 密钥
   * @return this
   */
  public DefaultHMacEngine init(String algorithm, byte[] key) {
    return init(algorithm, (null == key) ? null : new SecretKeySpec(key, algorithm));
  }

  /**
   * 初始化
   *
   * @param algorithm 算法
   * @param key 密钥 {@link SecretKey}
   * @return this
   * @throws CryptoException Cause by IOException
   */
  public DefaultHMacEngine init(String algorithm, SecretKey key) {
    try {
      mac = SecureUtil.createMac(algorithm);
      if (null == key) {
        key = SecureUtil.generateKey(algorithm);
      }
      mac.init(key);
    } catch (Exception e) {
      throw new CryptoException(e);
    }
    return this;
  }

  @Override
  public byte[] digest(InputStream data, int bufferLength) {
    if (bufferLength < 1) {
      bufferLength = IoUtil.DEFAULT_BUFFER_SIZE;
    }
    byte[] buffer = new byte[bufferLength];

    byte[] result = null;
    try {
      int read = data.read(buffer, 0, bufferLength);

      while (read > -1) {
        mac.update(buffer, 0, read);
        read = data.read(buffer, 0, bufferLength);
      }
      result = mac.doFinal();
    } catch (IOException e) {
      throw new CryptoException(e);
    } finally {
      mac.reset();
    }
    return result;
  }

  /**
   * 获得 {@link Mac}
   *
   * @return {@link Mac}
   */
  public Mac getMac() {
    return mac;
  }
}