1 /*
   2  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 import java.security.MessageDigest;
  25 import java.security.NoSuchAlgorithmException;
  26 import java.security.cert.Certificate;
  27 import java.security.cert.CertificateEncodingException;
  28 import java.security.cert.CertificateFactory;
  29 import java.security.cert.X509Certificate;
  30 import java.util.Collection;
  31 
  32 /**
  33  * This is the tool to convert blacklisted.certs.pem to blacklisted.certs.
  34  * Every time a new blacklisted certs is added, please append the PEM format
  35  * to the end of blacklisted.certs.pem (with proper comments) and then use
  36  * this tool to generate an updated blacklisted.certs. Make sure to include
  37  * changes to both in a changeset.
  38  */
  39 public class BlacklistedCertsConverter {
  40     public static void main(String[] args) throws Exception {
  41         if (args.length == 0) {
  42             System.out.println("Usage: java BlacklistedCertsConverter SHA-256" +
  43                     " < blacklisted.certs.pem > blacklisted.certs");
  44             System.exit(1);
  45         }
  46         String mdAlg = args[0];
  47         CertificateFactory cf = CertificateFactory.getInstance("X.509");
  48         Collection<? extends Certificate> certs
  49                 = cf.generateCertificates(System.in);
  50         System.out.println("Algorithm=" + mdAlg);
  51         for (Certificate cert: certs) {
  52             System.out.println(
  53                     getCertificateFingerPrint(mdAlg, (X509Certificate)cert));
  54         }
  55     }
  56 
  57     /**
  58      * Converts a byte to hex digit and writes to the supplied buffer
  59      */
  60     private static void byte2hex(byte b, StringBuffer buf) {
  61         char[] hexChars = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
  62                 '9', 'A', 'B', 'C', 'D', 'E', 'F' };
  63         int high = ((b & 0xf0) >> 4);
  64         int low = (b & 0x0f);
  65         buf.append(hexChars[high]);
  66         buf.append(hexChars[low]);
  67     }
  68 
  69     /**
  70      * Gets the requested finger print of the certificate.
  71      */
  72     private static String getCertificateFingerPrint(String mdAlg,
  73                                                     X509Certificate cert) {
  74         String fingerPrint = "";
  75         try {
  76             byte[] encCertInfo = cert.getEncoded();
  77             MessageDigest md = MessageDigest.getInstance(mdAlg);
  78             byte[] digest = md.digest(encCertInfo);
  79             StringBuffer buf = new StringBuffer();
  80             for (int i = 0; i < digest.length; i++) {
  81                 byte2hex(digest[i], buf);
  82             }
  83             fingerPrint = buf.toString();
  84         } catch (NoSuchAlgorithmException | CertificateEncodingException e) {
  85             // ignored
  86         }
  87         return fingerPrint;
  88     }
  89 }