| /* |
| * Copyright 1999,2004 The Apache Software Foundation. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| |
| package org.apache.catalina.util; |
| |
| |
| /** |
| * Encode an MD5 digest into a String. |
| * <p> |
| * The 128 bit MD5 hash is converted into a 32 character long String. |
| * Each character of the String is the hexadecimal representation of 4 bits |
| * of the digest. |
| * |
| * @author Remy Maucherat |
| * @version $Revision$ $Date$ |
| */ |
| |
| public final class MD5Encoder { |
| |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| |
| private static final char[] hexadecimal = |
| {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
| 'a', 'b', 'c', 'd', 'e', 'f'}; |
| |
| |
| // --------------------------------------------------------- Public Methods |
| |
| |
| /** |
| * Encodes the 128 bit (16 bytes) MD5 into a 32 character String. |
| * |
| * @param binaryData Array containing the digest |
| * @return Encoded MD5, or null if encoding failed |
| */ |
| public String encode( byte[] binaryData ) { |
| |
| if (binaryData.length != 16) |
| return null; |
| |
| char[] buffer = new char[32]; |
| |
| for (int i=0; i<16; i++) { |
| int low = (int) (binaryData[i] & 0x0f); |
| int high = (int) ((binaryData[i] & 0xf0) >> 4); |
| buffer[i*2] = hexadecimal[high]; |
| buffer[i*2 + 1] = hexadecimal[low]; |
| } |
| |
| return new String(buffer); |
| |
| } |
| |
| |
| } |
| |