1 /* 2 * Copyright [2005] [University Corporation for Advanced Internet Development, Inc.] 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.opensaml.common.impl; 18 19 import java.security.NoSuchAlgorithmException; 20 import java.security.SecureRandom; 21 22 import org.bouncycastle.util.encoders.Hex; 23 import org.opensaml.common.IdentifierGenerator; 24 25 /** 26 * Generates identifiers using random data obtained from a {@link java.security.SecureRandom} instance. 27 */ 28 public class SecureRandomIdentifierGenerator implements IdentifierGenerator { 29 30 /** Random number generator. */ 31 private static SecureRandom random; 32 33 /** 34 * Constructor. 35 * 36 * @throws NoSuchAlgorithmException thrown if the SHA1PRNG algorithm is not supported by the JVM 37 */ 38 public SecureRandomIdentifierGenerator() throws NoSuchAlgorithmException { 39 random = SecureRandom.getInstance("SHA1PRNG"); 40 } 41 42 /** 43 * Constructor. 44 * 45 * @param algorithm the random number generation algorithm to use 46 * 47 * @throws NoSuchAlgorithmException thrown if the algorithm is not supported by the JVM 48 */ 49 public SecureRandomIdentifierGenerator(String algorithm) throws NoSuchAlgorithmException { 50 random = SecureRandom.getInstance(algorithm); 51 } 52 53 /** {@inheritDoc} */ 54 public String generateIdentifier() { 55 return generateIdentifier(16); 56 } 57 58 /** {@inheritDoc} */ 59 public String generateIdentifier(int size) { 60 byte[] buf = new byte[size]; 61 random.nextBytes(buf); 62 return "_".concat(new String(Hex.encode(buf))); 63 } 64 }