OmemoBundleElement.java
/**
*
* Copyright 2017 Paul Schaub
*
* 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.jivesoftware.smackx.omemo.element;
import java.util.HashMap;
import java.util.Map;
import org.jivesoftware.smack.packet.ExtensionElement;
import org.jivesoftware.smack.util.StringUtils;
import org.jivesoftware.smack.util.XmlStringBuilder;
import org.jivesoftware.smack.util.stringencoder.Base64;
/**
* Class that represents an OMEMO Bundle element.
*
* @author Paul Schaub
*/
public abstract class OmemoBundleElement implements ExtensionElement {
public static final String BUNDLE = "bundle";
public static final String SIGNED_PRE_KEY_PUB = "signedPreKeyPublic";
public static final String SIGNED_PRE_KEY_ID = "signedPreKeyId";
public static final String SIGNED_PRE_KEY_SIG = "signedPreKeySignature";
public static final String IDENTITY_KEY = "identityKey";
public static final String PRE_KEYS = "prekeys";
public static final String PRE_KEY_PUB = "preKeyPublic";
public static final String PRE_KEY_ID = "preKeyId";
private final int signedPreKeyId;
private final String signedPreKeyB64;
private byte[] signedPreKey;
private final String signedPreKeySignatureB64;
private byte[] signedPreKeySignature;
private final String identityKeyB64;
private byte[] identityKey;
private final HashMap<Integer, String> preKeysB64;
private HashMap<Integer, byte[]> preKeys;
/**
* Constructor to create a Bundle Element from base64 Strings.
*
* @param signedPreKeyId id
* @param signedPreKeyB64 base64 encoded signedPreKey
* @param signedPreKeySigB64 base64 encoded signedPreKeySignature
* @param identityKeyB64 base64 encoded identityKey
* @param preKeysB64 HashMap of base64 encoded preKeys
*/
public OmemoBundleElement(int signedPreKeyId, String signedPreKeyB64, String signedPreKeySigB64, String identityKeyB64, HashMap<Integer, String> preKeysB64) {
if (signedPreKeyId < 0) {
throw new IllegalArgumentException("signedPreKeyId MUST be greater than or equal to 0.");
}
this.signedPreKeyId = signedPreKeyId;
this.signedPreKeyB64 = StringUtils.requireNotNullNorEmpty(signedPreKeyB64, "signedPreKeyB64 MUST NOT be null nor empty.");
this.signedPreKeySignatureB64 = StringUtils.requireNotNullNorEmpty(signedPreKeySigB64, "signedPreKeySigB64 MUST NOT be null nor empty.");
this.identityKeyB64 = StringUtils.requireNotNullNorEmpty(identityKeyB64, "identityKeyB64 MUST NOT be null nor empty.");
if (preKeysB64 == null || preKeysB64.isEmpty()) {
throw new IllegalArgumentException("PreKeys MUST NOT be null nor empty.");
}
this.preKeysB64 = preKeysB64;
}
/**
* Constructor to create a Bundle Element from decoded byte arrays.
*
* @param signedPreKeyId id
* @param signedPreKey signedPreKey
* @param signedPreKeySig signedPreKeySignature
* @param identityKey identityKey
* @param preKeys HashMap of preKeys
*/
public OmemoBundleElement(int signedPreKeyId, byte[] signedPreKey, byte[] signedPreKeySig, byte[] identityKey, HashMap<Integer, byte[]> preKeys) {
this(signedPreKeyId,
signedPreKey != null ? Base64.encodeToString(signedPreKey) : null,
signedPreKeySig != null ? Base64.encodeToString(signedPreKeySig) : null,
identityKey != null ? Base64.encodeToString(identityKey) : null,
base64EncodePreKeys(preKeys));
this.signedPreKey = signedPreKey;
this.signedPreKeySignature = signedPreKeySig;
this.identityKey = identityKey;
this.preKeys = preKeys;
}
private static HashMap<Integer, String> base64EncodePreKeys(HashMap<Integer, byte[]> preKeys) {
if (preKeys == null) {
return null;
}
HashMap<Integer, String> converted = new HashMap<>();
for (Integer id : preKeys.keySet()) {
converted.put(id, Base64.encodeToString(preKeys.get(id)));
}
return converted;
}
/**
* Return the signedPreKey of the OmemoBundleElement.
*
* @return signedPreKey as byte array
*/
public byte[] getSignedPreKey() {
if (signedPreKey == null) {
signedPreKey = Base64.decode(signedPreKeyB64);
}
return this.signedPreKey.clone();
}
/**
* Return the id of the signedPreKey in the bundle.
*
* @return id of signedPreKey
*/
public int getSignedPreKeyId() {
return this.signedPreKeyId;
}
/**
* Get the signature of the signedPreKey.
*
* @return signature as byte array
*/
public byte[] getSignedPreKeySignature() {
if (signedPreKeySignature == null) {
signedPreKeySignature = Base64.decode(signedPreKeySignatureB64);
}
return signedPreKeySignature.clone();
}
/**
* Return the public identityKey of the bundles owner.
* This can be used to check the signedPreKeys signature.
* The fingerprint of this key is, what the user has to verify.
*
* @return public identityKey as byte array
*/
public byte[] getIdentityKey() {
if (identityKey == null) {
identityKey = Base64.decode(identityKeyB64);
}
return this.identityKey.clone();
}
/**
* Return the HashMap of preKeys in the bundle.
* The map uses the preKeys ids as key and the preKeys as value.
*
* @return preKeys Pre-Keys contained in the bundle
*/
public HashMap<Integer, byte[]> getPreKeys() {
if (preKeys == null) {
preKeys = new HashMap<>();
for (int id : preKeysB64.keySet()) {
preKeys.put(id, Base64.decode(preKeysB64.get(id)));
}
}
return this.preKeys;
}
/**
* Return a single preKey from the map.
*
* @param id id of the preKey
* @return the preKey
*/
public byte[] getPreKey(int id) {
return getPreKeys().get(id);
}
@Override
public String getElementName() {
return BUNDLE;
}
@Override
public XmlStringBuilder toXML(org.jivesoftware.smack.packet.XmlEnvironment enclosingNamespace) {
XmlStringBuilder sb = new XmlStringBuilder(this, enclosingNamespace).rightAngleBracket();
sb.halfOpenElement(SIGNED_PRE_KEY_PUB).attribute(SIGNED_PRE_KEY_ID, signedPreKeyId).rightAngleBracket()
.append(signedPreKeyB64).closeElement(SIGNED_PRE_KEY_PUB);
sb.openElement(SIGNED_PRE_KEY_SIG).append(signedPreKeySignatureB64).closeElement(SIGNED_PRE_KEY_SIG);
sb.openElement(IDENTITY_KEY).append(identityKeyB64).closeElement(IDENTITY_KEY);
sb.openElement(PRE_KEYS);
for (Map.Entry<Integer, String> p : this.preKeysB64.entrySet()) {
sb.halfOpenElement(PRE_KEY_PUB).attribute(PRE_KEY_ID, p.getKey()).rightAngleBracket()
.append(p.getValue()).closeElement(PRE_KEY_PUB);
}
sb.closeElement(PRE_KEYS);
sb.closeElement(this);
return sb;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder("OmemoBundleElement[\n");
sb.append(SIGNED_PRE_KEY_PUB).append(' ').append(SIGNED_PRE_KEY_ID).append('=').append(signedPreKeyId)
.append(':').append(signedPreKeyB64).append('\n')
.append(SIGNED_PRE_KEY_SIG).append(": ").append(signedPreKeySignatureB64).append('\n')
.append(IDENTITY_KEY).append(": ").append(identityKeyB64).append('\n')
.append(PRE_KEYS).append(" (").append(preKeysB64.size()).append(")\n");
for (Map.Entry<Integer, String> e : preKeysB64.entrySet()) {
sb.append(PRE_KEY_PUB).append(' ').append(PRE_KEY_ID).append('=').append(e.getKey()).append(": ").append(e.getValue()).append('\n');
}
sb.append(']');
return sb.toString();
}
@Override
public boolean equals(Object other) {
if (!(other instanceof OmemoBundleElement)) {
return false;
}
OmemoBundleElement otherOmemoBundleElement = (OmemoBundleElement) other;
return toXML().toString().equals(otherOmemoBundleElement.toXML().toString());
}
@Override
public int hashCode() {
return toXML().toString().hashCode();
}
}