/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.vysper.xmpp.modules.extension.xep0220_server_dailback; import java.io.UnsupportedEncodingException; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; import java.util.UUID; import javax.crypto.Mac; import javax.crypto.spec.SecretKeySpec; import org.apache.commons.codec.binary.Hex; import org.apache.commons.codec.digest.DigestUtils; import org.apache.commons.lang.Validate; import org.apache.vysper.xmpp.addressing.Entity; public class DialbackIdGenerator { // generates a shared secret within the server private static final String SECRET = UUID.randomUUID().toString(); private SecretKeySpec signingKey = new SecretKeySpec(DigestUtils.sha256(SECRET), "HmacSHA256"); private Mac mac; public DialbackIdGenerator() { try { mac = Mac.getInstance("HmacSHA256"); mac.init(signingKey); } catch (NoSuchAlgorithmException e) { throw new RuntimeException(e); } catch (InvalidKeyException e) { throw new RuntimeException(e); } } public String generate(Entity receiving, Entity originating, String streamId) { Validate.notNull(receiving, "receiving can not be null"); Validate.notNull(originating, "originating can not be null"); Validate.notNull(streamId, "streamId can not be null"); try { mac.update(receiving.getDomain().getBytes("UTF-16")); mac.update(" ".getBytes("UTF-16")); mac.update(originating.getDomain().getBytes("UTF-16")); mac.update(" ".getBytes("UTF-16")); mac.update(streamId.getBytes("UTF-16")); byte[] rawHmac = mac.doFinal(); return Hex.encodeHexString(rawHmac); } catch (UnsupportedEncodingException e) { throw new RuntimeException(e); } } public boolean verify(String dailbackId, Entity receiving, Entity originating, String streamId) { return dailbackId.equals(generate(receiving, originating, streamId)); } }