001/**
002 * Copyright 2010-2014 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.kuali.common.util;
017
018import java.io.ByteArrayInputStream;
019import java.io.IOException;
020import java.io.InputStream;
021import java.io.UnsupportedEncodingException;
022import java.security.MessageDigest;
023import java.security.NoSuchAlgorithmException;
024
025public class CheckSumUtils {
026
027        private static final String MD5 = "MD5";
028        private static final String SHA1 = "SHA1";
029        private static final String UTF8 = Encodings.UTF8;
030
031        public static String getSHA1Checksum(String message) {
032                return getChecksum(message, SHA1);
033        }
034
035        public static String getMD5Checksum(String message) {
036                return getChecksum(message, MD5);
037        }
038
039        public static String getMD5Checksum(InputStream in) throws IOException {
040                return getChecksum(in, MD5);
041        }
042
043        public static String getSHA1Checksum(InputStream in) throws IOException {
044                return getChecksum(in, SHA1);
045        }
046
047        public static String getChecksum(String message, String algorithm) {
048                try {
049                        return getChecksum(getInputStream(message), algorithm);
050                } catch (IOException e) {
051                        throw new IllegalStateException("Unexpected IO error", e);
052                }
053        }
054
055        public static String getChecksum(InputStream in, String algorithm) throws IOException {
056                try {
057                        byte[] buffer = new byte[1024];
058                        MessageDigest complete = MessageDigest.getInstance(algorithm);
059                        int numRead;
060                        do {
061                                numRead = in.read(buffer);
062                                if (numRead > 0) {
063                                        complete.update(buffer, 0, numRead);
064                                }
065                        } while (numRead != -1);
066                        byte[] bytes = complete.digest();
067                        return toHex(bytes);
068                } catch (NoSuchAlgorithmException e) {
069                        throw new IllegalStateException("Unexpected message digest error", e);
070                } catch (IOException e) {
071                        throw e;
072                }
073        }
074
075        protected static String toHex(byte[] bytes) {
076                StringBuilder sb = new StringBuilder();
077                for (int i = 0; i < bytes.length; i++) {
078                        sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
079                }
080                return sb.toString();
081        }
082
083        protected static InputStream getInputStream(String message) {
084                try {
085                        return getInputStream(message, UTF8);
086                } catch (IOException e) {
087                        throw new IllegalStateException(e);
088                }
089        }
090
091        protected static InputStream getInputStream(String message, String encoding) throws UnsupportedEncodingException {
092                Assert.noBlanks(message);
093                byte[] bytes = message.getBytes(encoding);
094                return new ByteArrayInputStream(bytes);
095        }
096
097}