cn.bestwu.api.test.Sha1DigestUtil Maven / Gradle / Ivy

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package cn.bestwu.api.test;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Sha1加密工具类
 *
 * @author Peter Wu
 */
public class Sha1DigestUtil {

  /**
   * Returns an SHA digest.
   *
   * @return An SHA digest instance.
   * @throws RuntimeException when a {@link NoSuchAlgorithmException} is caught.
   */
  private static MessageDigest getSha1Digest() {
    try {
      return MessageDigest.getInstance("SHA-1");
    } catch (NoSuchAlgorithmException e) {
      throw new RuntimeException(e.getMessage());
    }
  }

  /**
   * Calculates the SHA digest and returns the value as a {@code byte[]}.
   *
   * @param data Data to digest
   * @return SHA digest
   */
  public static byte[] sha(byte[] data) {
    return getSha1Digest().digest(data);
  }

  /**
   * Calculates the SHA digest and returns the value as a {@code byte[]}.
   *
   * @param data Data to digest
   * @return SHA digest
   */
  public static byte[] sha(String data) {
    return sha(data.getBytes());
  }

  /**
   * Calculates the SHA digest and returns the value as a hex string.
   *
   * @param data Data to digest
   * @return SHA digest as a hex string
   */
  public static String shaHex(byte[] data) {
    return new String(Hex.encode(sha(data)));
  }

  /**
   * Calculates the SHA digest and returns the value as a hex string.
   *
   * @param data Data to digest
   * @return SHA digest as a hex string
   */
  public static String shaHex(String data) {
    return new String(Hex.encode(sha(data)));
  }

  public static final class Hex {

    private static final char[] HEX = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
        'a', 'b', 'c', 'd', 'e', 'f'};

    public static char[] encode(byte[] bytes) {
      final int nBytes = bytes.length;
      char[] result = new char[2 * nBytes];

      int j = 0;
      for (byte aByte : bytes) {
        // Char for top 4 bits
        result[j++] = HEX[(0xF0 & aByte) >>> 4];
        // Bottom 4
        result[j++] = HEX[(0x0F & aByte)];
      }

      return result;
    }

    public static byte[] decode(CharSequence s) {
      int nChars = s.length();

      if (nChars % 2 != 0) {
        throw new IllegalArgumentException(
            "Hex-encoded string must have an even number of characters");
      }

      byte[] result = new byte[nChars / 2];

      for (int i = 0; i < nChars; i += 2) {
        int msb = Character.digit(s.charAt(i), 16);
        int lsb = Character.digit(s.charAt(i + 1), 16);

        if (msb < 0 || lsb < 0) {
          throw new IllegalArgumentException("Non-hex character in input: " + s);
        }
        result[i / 2] = (byte) ((msb << 4) | lsb);
      }
      return result;
    }

  }

}