com.dahuatech.hutool.crypto.digest.mac.BCHMacEngine 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 org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.Mac;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;

import java.io.IOException;
import java.io.InputStream;

/**
 * BouncyCastle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 BCHMacEngine implements MacEngine {

  private Mac mac;

  // -------------------------------------------------------------------------------------------
  // Constructor start
  /**
   * 构造
   *
   * @param digest 摘要算法，为{@link Digest} 的接口实现
   * @param key 密钥
   * @since 4.5.13
   */
  public BCHMacEngine(Digest digest, byte[] key) {
    this(digest, new KeyParameter(key));
  }

  /**
   * 构造
   *
   * @param digest 摘要算法
   * @param params 参数，例如密钥可以用{@link KeyParameter}
   * @since 4.5.13
   */
  public BCHMacEngine(Digest digest, CipherParameters params) {
    init(digest, params);
  }
  // -------------------------------------------------------------------------------------------
  // Constructor end

  /**
   * 初始化
   *
   * @param digest 摘要算法
   * @param params 参数，例如密钥可以用{@link KeyParameter}
   * @return this
   */
  public BCHMacEngine init(Digest digest, CipherParameters params) {
    mac = new HMac(digest);
    mac.init(params);
    return this;
  }

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

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

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

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