spill.java

用java语言实现的认证程序

import java.io.*;
import java.security.KeyStore;
import java.security.MessageDigest;
import java.security.cert.X509Certificate;

import oreilly.jonathan.util.Base64;

public class Spill {
  public static void main(String[] args) throws Exception {
    if (args.length != 1) {
      System.out.println("Usage: Spill file");
      return;
    }

    BufferedReader in = new BufferedReader(new FileReader(args[0]));
    String begin = in.readLine();
    if (begin.equals("-----BEGIN CERTIFICATE-----") == false)
      throw new IOException("Couldn't find certificate beginning");
    String base64 = new String();
    boolean trucking = true;
    while (trucking) {
      String line = in.readLine();
      if (line.startsWith("-----")) trucking = false;
      else base64 += line;
    }
    in.close();
    byte[] certificateData = Base64.decode(base64);

    X509Certificate c = X509Certificate.getInstance(certificateData);

    System.out.println("Subject: " + c.getSubjectDN().getName());
    System.out.println("Issuer : " + c.getIssuerDN().getName());
    System.out.println("Serial number: " +
        c.getSerialNumber().toString(16));
    System.out.println("Valid from " + c.getNotBefore() +
        " to " + c.getNotAfter());

    System.out.println("Fingerprints:");
    doFingerprint(certificateData, "MD5");
    doFingerprint(certificateData, "SHA");
  }

  protected static void doFingerprint(byte[] certificateBytes,
      String algorithm) throws Exception {
    System.out.print("  " + algorithm + ": ");
    MessageDigest md = MessageDigest.getInstance(algorithm);
    md.update(certificateBytes);
    byte[] digest = md.digest();

    for (int i = 0; i < digest.length; i++) {
      if (i != 0) System.out.print(":");
      int b = digest[i] & 0xff;
      String hex = Integer.toHexString(b);
      if (hex.length() == 1) System.out.print("0");
      System.out.print(hex);
    }
    System.out.println();
  }
}