diff options
Diffstat (limited to 'src/main/java/eu/siacs/conversations/crypto')
3 files changed, 456 insertions, 38 deletions
diff --git a/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java b/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java index 8e3002487..eae7a9abc 100644 --- a/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java +++ b/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java @@ -1,15 +1,29 @@ package eu.siacs.conversations.crypto.axolotl; +import android.util.Base64; import android.util.Log; import org.whispersystems.libaxolotl.AxolotlAddress; +import org.whispersystems.libaxolotl.DuplicateMessageException; import org.whispersystems.libaxolotl.IdentityKey; import org.whispersystems.libaxolotl.IdentityKeyPair; import org.whispersystems.libaxolotl.InvalidKeyException; import org.whispersystems.libaxolotl.InvalidKeyIdException; +import org.whispersystems.libaxolotl.InvalidMessageException; +import org.whispersystems.libaxolotl.InvalidVersionException; +import org.whispersystems.libaxolotl.LegacyMessageException; +import org.whispersystems.libaxolotl.NoSessionException; +import org.whispersystems.libaxolotl.SessionBuilder; +import org.whispersystems.libaxolotl.SessionCipher; +import org.whispersystems.libaxolotl.UntrustedIdentityException; import org.whispersystems.libaxolotl.ecc.Curve; import org.whispersystems.libaxolotl.ecc.ECKeyPair; +import org.whispersystems.libaxolotl.ecc.ECPublicKey; +import org.whispersystems.libaxolotl.protocol.CiphertextMessage; +import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage; +import org.whispersystems.libaxolotl.protocol.WhisperMessage; import org.whispersystems.libaxolotl.state.AxolotlStore; +import org.whispersystems.libaxolotl.state.PreKeyBundle; import org.whispersystems.libaxolotl.state.PreKeyRecord; import org.whispersystems.libaxolotl.state.SessionRecord; import org.whispersystems.libaxolotl.state.SignedPreKeyRecord; @@ -17,43 +31,50 @@ import org.whispersystems.libaxolotl.util.KeyHelper; import java.util.ArrayList; import java.util.HashMap; +import java.util.HashSet; import java.util.List; import java.util.Map; +import java.util.Random; +import java.util.Set; import eu.siacs.conversations.Config; import eu.siacs.conversations.entities.Account; +import eu.siacs.conversations.entities.Contact; import eu.siacs.conversations.entities.Conversation; -import eu.siacs.conversations.entities.Message; import eu.siacs.conversations.services.XmppConnectionService; import eu.siacs.conversations.xmpp.jid.InvalidJidException; import eu.siacs.conversations.xmpp.jid.Jid; public class AxolotlService { - private Account account; - private XmppConnectionService mXmppConnectionService; - private SQLiteAxolotlStore axolotlStore; - private Map<Jid,XmppAxolotlSession> sessions; + private final Account account; + private final XmppConnectionService mXmppConnectionService; + private final SQLiteAxolotlStore axolotlStore; + private final SessionMap sessions; + private int ownDeviceId; public static class SQLiteAxolotlStore implements AxolotlStore { public static final String PREKEY_TABLENAME = "prekeys"; public static final String SIGNED_PREKEY_TABLENAME = "signed_prekeys"; - public static final String SESSION_TABLENAME = "signed_prekeys"; - public static final String NAME = "name"; + public static final String SESSION_TABLENAME = "sessions"; + public static final String ACCOUNT = "account"; public static final String DEVICE_ID = "device_id"; public static final String ID = "id"; public static final String KEY = "key"; - public static final String ACCOUNT = "account"; + public static final String NAME = "name"; + public static final String TRUSTED = "trusted"; public static final String JSONKEY_IDENTITY_KEY_PAIR = "axolotl_key"; public static final String JSONKEY_REGISTRATION_ID = "axolotl_reg_id"; + public static final String JSONKEY_CURRENT_PREKEY_ID = "axolotl_cur_prekey_id"; private final Account account; private final XmppConnectionService mXmppConnectionService; private final IdentityKeyPair identityKeyPair; private final int localRegistrationId; + private int currentPreKeyId = 0; private static IdentityKeyPair generateIdentityKeyPair() { @@ -75,6 +96,14 @@ public class AxolotlService { this.mXmppConnectionService = service; this.identityKeyPair = loadIdentityKeyPair(); this.localRegistrationId = loadRegistrationId(); + this.currentPreKeyId = loadCurrentPreKeyId(); + for( SignedPreKeyRecord record:loadSignedPreKeys()) { + Log.d(Config.LOGTAG, "Got Axolotl signed prekey record:" + record.getId()); + } + } + + public int getCurrentPreKeyId() { + return currentPreKeyId; } // -------------------------------------- @@ -86,21 +115,22 @@ public class AxolotlService { IdentityKeyPair ownKey; if( serializedKey != null ) { try { - ownKey = new IdentityKeyPair(serializedKey.getBytes()); + ownKey = new IdentityKeyPair(Base64.decode(serializedKey,Base64.DEFAULT)); + return ownKey; } catch (InvalidKeyException e) { Log.d(Config.LOGTAG, "Invalid key stored for account " + account.getJid() + ": " + e.getMessage()); - return null; +// return null; } - } else { + } //else { Log.d(Config.LOGTAG, "Could not retrieve axolotl key for account " + account.getJid()); ownKey = generateIdentityKeyPair(); - boolean success = this.account.setKey(JSONKEY_IDENTITY_KEY_PAIR, new String(ownKey.serialize())); + boolean success = this.account.setKey(JSONKEY_IDENTITY_KEY_PAIR, Base64.encodeToString(ownKey.serialize(), Base64.DEFAULT)); if(success) { mXmppConnectionService.databaseBackend.updateAccount(account); } else { Log.e(Config.LOGTAG, "Failed to write new key to the database!"); } - } + //} return ownKey; } @@ -122,6 +152,19 @@ public class AxolotlService { return reg_id; } + private int loadCurrentPreKeyId() { + String regIdString = this.account.getKey(JSONKEY_CURRENT_PREKEY_ID); + int reg_id; + if (regIdString != null) { + reg_id = Integer.valueOf(regIdString); + } else { + Log.d(Config.LOGTAG, "Could not retrieve current prekey id for account " + account.getJid()); + reg_id = 0; + } + return reg_id; + } + + /** * Get the local client's identity key pair. * @@ -159,7 +202,7 @@ public class AxolotlService { Jid contactJid = Jid.fromString(name); Conversation conversation = this.mXmppConnectionService.find(this.account, contactJid); if (conversation != null) { - conversation.getContact().addAxolotlIdentityKey(identityKey, false); + conversation.getContact().addAxolotlIdentityKey(identityKey); mXmppConnectionService.updateConversationUi(); mXmppConnectionService.syncRosterToDisk(conversation.getAccount()); } @@ -188,8 +231,8 @@ public class AxolotlService { Jid contactJid = Jid.fromString(name); Conversation conversation = this.mXmppConnectionService.find(this.account, contactJid); if (conversation != null) { - List<IdentityKey> trustedKeys = conversation.getContact().getTrustedAxolotlIdentityKeys(); - return trustedKeys.contains(identityKey); + List<IdentityKey> trustedKeys = conversation.getContact().getAxolotlIdentityKeys(); + return trustedKeys.isEmpty() || trustedKeys.contains(identityKey); } else { return false; } @@ -274,7 +317,15 @@ public class AxolotlService { @Override public void deleteAllSessions(String name) { mXmppConnectionService.databaseBackend.deleteAllSessions(account, - new AxolotlAddress(name,0)); + new AxolotlAddress(name, 0)); + } + + public boolean isTrustedSession(AxolotlAddress address) { + return mXmppConnectionService.databaseBackend.isTrustedSession(this.account, address); + } + + public void setTrustedSession(AxolotlAddress address, boolean trusted) { + mXmppConnectionService.databaseBackend.setTrustedSession(this.account, address,trusted); } // -------------------------------------- @@ -292,7 +343,7 @@ public class AxolotlService { public PreKeyRecord loadPreKey(int preKeyId) throws InvalidKeyIdException { PreKeyRecord record = mXmppConnectionService.databaseBackend.loadPreKey(account, preKeyId); if(record == null) { - throw new InvalidKeyIdException("No such PreKeyRecord!"); + throw new InvalidKeyIdException("No such PreKeyRecord: " + preKeyId); } return record; } @@ -306,6 +357,13 @@ public class AxolotlService { @Override public void storePreKey(int preKeyId, PreKeyRecord record) { mXmppConnectionService.databaseBackend.storePreKey(account, record); + currentPreKeyId = preKeyId; + boolean success = this.account.setKey(JSONKEY_CURRENT_PREKEY_ID,Integer.toString(preKeyId)); + if(success) { + mXmppConnectionService.databaseBackend.updateAccount(account); + } else { + Log.e(Config.LOGTAG, "Failed to write new prekey id to the database!"); + } } /** @@ -342,7 +400,7 @@ public class AxolotlService { public SignedPreKeyRecord loadSignedPreKey(int signedPreKeyId) throws InvalidKeyIdException { SignedPreKeyRecord record = mXmppConnectionService.databaseBackend.loadSignedPreKey(account, signedPreKeyId); if(record == null) { - throw new InvalidKeyIdException("No such PreKeyRecord!"); + throw new InvalidKeyIdException("No such SignedPreKeyRecord: " + signedPreKeyId); } return record; } @@ -388,53 +446,229 @@ public class AxolotlService { } } - private static class XmppAxolotlSession { - private List<Message> untrustedMessages; - private AxolotlStore axolotlStore; - - public XmppAxolotlSession(SQLiteAxolotlStore axolotlStore) { - this.untrustedMessages = new ArrayList<>(); - this.axolotlStore = axolotlStore; + public static class XmppAxolotlSession { + private SessionCipher cipher; + private boolean isTrusted = false; + private SQLiteAxolotlStore sqLiteAxolotlStore; + private AxolotlAddress remoteAddress; + + public XmppAxolotlSession(SQLiteAxolotlStore store, AxolotlAddress remoteAddress) { + this.cipher = new SessionCipher(store, remoteAddress); + this.remoteAddress = remoteAddress; + this.sqLiteAxolotlStore = store; + this.isTrusted = sqLiteAxolotlStore.isTrustedSession(remoteAddress); } public void trust() { - for (Message message : this.untrustedMessages) { - message.trust(); - } - this.untrustedMessages = null; + sqLiteAxolotlStore.setTrustedSession(remoteAddress, true); + this.isTrusted = true; } public boolean isTrusted() { - return (this.untrustedMessages == null); + return this.isTrusted; } - public String processReceiving(XmppAxolotlMessage incomingMessage) { - return null; + public byte[] processReceiving(XmppAxolotlMessage.XmppAxolotlMessageHeader incomingHeader) { + byte[] plaintext = null; + try { + try { + PreKeyWhisperMessage message = new PreKeyWhisperMessage(incomingHeader.getContents()); + Log.d(Config.LOGTAG,"PreKeyWhisperMessage ID:" + message.getSignedPreKeyId() + "/" + message.getPreKeyId()); + plaintext = cipher.decrypt(message); + } catch (InvalidMessageException|InvalidVersionException e) { + WhisperMessage message = new WhisperMessage(incomingHeader.getContents()); + plaintext = cipher.decrypt(message); + } catch (InvalidKeyException|InvalidKeyIdException| UntrustedIdentityException e) { + Log.d(Config.LOGTAG, "Error decrypting axolotl header: " + e.getMessage()); + } + } catch (LegacyMessageException|InvalidMessageException e) { + Log.d(Config.LOGTAG, "Error decrypting axolotl header: " + e.getMessage()); + } catch (DuplicateMessageException|NoSessionException e) { + Log.d(Config.LOGTAG, "Error decrypting axolotl header: " + e.getMessage()); + } + return plaintext; } - public XmppAxolotlMessage processSending(String outgoingMessage) { - return null; + public XmppAxolotlMessage.XmppAxolotlMessageHeader processSending(byte[] outgoingMessage) { + CiphertextMessage ciphertextMessage = cipher.encrypt(outgoingMessage); + XmppAxolotlMessage.XmppAxolotlMessageHeader header = + new XmppAxolotlMessage.XmppAxolotlMessageHeader(remoteAddress.getDeviceId(), + ciphertextMessage.serialize()); + return header; } } + private static class AxolotlAddressMap<T> { + protected Map<String, Map<Integer,T>> map; + protected final Object MAP_LOCK = new Object(); + + public AxolotlAddressMap() { + this.map = new HashMap<>(); + } + + public void put(AxolotlAddress address, T value) { + synchronized (MAP_LOCK) { + Map<Integer, T> devices = map.get(address.getName()); + if (devices == null) { + devices = new HashMap<>(); + map.put(address.getName(), devices); + } + devices.put(address.getDeviceId(), value); + } + } + + public T get(AxolotlAddress address) { + synchronized (MAP_LOCK) { + Map<Integer, T> devices = map.get(address.getName()); + if(devices == null) { + return null; + } + return devices.get(address.getDeviceId()); + } + } + + public Map<Integer, T> getAll(AxolotlAddress address) { + synchronized (MAP_LOCK) { + Map<Integer, T> devices = map.get(address.getName()); + if(devices == null) { + return new HashMap<>(); + } + return devices; + } + } + + public boolean hasAny(AxolotlAddress address) { + synchronized (MAP_LOCK) { + Map<Integer, T> devices = map.get(address.getName()); + return devices != null && !devices.isEmpty(); + } + } + + + } + + private static class SessionMap extends AxolotlAddressMap<XmppAxolotlSession> { + + public SessionMap(SQLiteAxolotlStore store, Account account) { + super(); + this.fillMap(store, account); + } + + private void fillMap(SQLiteAxolotlStore store, Account account) { + for(Contact contact:account.getRoster().getContacts()){ + Jid bareJid = contact.getJid().toBareJid(); + if(bareJid == null) { + continue; // FIXME: handle this? + } + String address = bareJid.toString(); + List<Integer> deviceIDs = store.getSubDeviceSessions(address); + for(Integer deviceId:deviceIDs) { + AxolotlAddress axolotlAddress = new AxolotlAddress(address, deviceId); + this.put(axolotlAddress, new XmppAxolotlSession(store, axolotlAddress)); + } + } + } + + } + + } + public AxolotlService(Account account, XmppConnectionService connectionService) { this.mXmppConnectionService = connectionService; this.account = account; this.axolotlStore = new SQLiteAxolotlStore(this.account, this.mXmppConnectionService); - this.sessions = new HashMap<>(); + this.sessions = new SessionMap(axolotlStore, account); + this.ownDeviceId = axolotlStore.getLocalRegistrationId(); } - public void trustSession(Jid counterpart) { + public void trustSession(AxolotlAddress counterpart) { XmppAxolotlSession session = sessions.get(counterpart); if(session != null) { session.trust(); } } - public boolean isTrustedSession(Jid counterpart) { + public boolean isTrustedSession(AxolotlAddress counterpart) { XmppAxolotlSession session = sessions.get(counterpart); return session != null && session.isTrusted(); } + private AxolotlAddress getAddressForJid(Jid jid) { + return new AxolotlAddress(jid.toString(), 0); + } + + private Set<XmppAxolotlSession> findOwnSessions() { + AxolotlAddress ownAddress = getAddressForJid(account.getJid()); + Set<XmppAxolotlSession> ownDeviceSessions = new HashSet<>(this.sessions.getAll(ownAddress).values()); + return ownDeviceSessions; + } + private Set<XmppAxolotlSession> findSessionsforContact(Contact contact) { + AxolotlAddress contactAddress = getAddressForJid(contact.getJid()); + Set<XmppAxolotlSession> sessions = new HashSet<>(this.sessions.getAll(contactAddress).values()); + return sessions; + } + + private boolean hasAny(Contact contact) { + AxolotlAddress contactAddress = getAddressForJid(contact.getJid()); + return sessions.hasAny(contactAddress); + } + + public int getOwnDeviceId() { + return ownDeviceId; + } + + private void createSessionsIfNeeded(Contact contact) throws NoSessionsCreatedException { + } + + public XmppAxolotlMessage processSending(Contact contact, String outgoingMessage) throws NoSessionsCreatedException { + XmppAxolotlMessage message = new XmppAxolotlMessage(contact, ownDeviceId, outgoingMessage); + createSessionsIfNeeded(contact); + Log.d(Config.LOGTAG, "Building axolotl foreign headers..."); + + for(XmppAxolotlSession session : findSessionsforContact(contact)) { +// if(!session.isTrusted()) { + // TODO: handle this properly + // continue; + // } + message.addHeader(session.processSending(message.getInnerKey())); + } + Log.d(Config.LOGTAG, "Building axolotl own headers..."); + for(XmppAxolotlSession session : findOwnSessions()) { + // if(!session.isTrusted()) { + // TODO: handle this properly + // continue; + // } + message.addHeader(session.processSending(message.getInnerKey())); + } + + return message; + } + + public XmppAxolotlMessage.XmppAxolotlPlaintextMessage processReceiving(XmppAxolotlMessage message) { + XmppAxolotlMessage.XmppAxolotlPlaintextMessage plaintextMessage = null; + AxolotlAddress senderAddress = new AxolotlAddress(message.getContact().getJid().toBareJid().toString(), + message.getSenderDeviceId()); + + XmppAxolotlSession session = sessions.get(senderAddress); + if (session == null) { + Log.d(Config.LOGTAG, "No axolotl session found while parsing received message " + message); + // TODO: handle this properly + session = new XmppAxolotlSession(axolotlStore, senderAddress); + + } + + for(XmppAxolotlMessage.XmppAxolotlMessageHeader header : message.getHeaders()) { + if (header.getRecipientDeviceId() == ownDeviceId) { + Log.d(Config.LOGTAG, "Found axolotl header matching own device ID, processing..."); + byte[] payloadKey = session.processReceiving(header); + if (payloadKey != null) { + Log.d(Config.LOGTAG, "Got payload key from axolotl header. Decrypting message..."); + plaintextMessage = message.decrypt(session, payloadKey); + } + } + } + + return plaintextMessage; + } } diff --git a/src/main/java/eu/siacs/conversations/crypto/axolotl/NoSessionsCreatedException.java b/src/main/java/eu/siacs/conversations/crypto/axolotl/NoSessionsCreatedException.java new file mode 100644 index 000000000..663b42b58 --- /dev/null +++ b/src/main/java/eu/siacs/conversations/crypto/axolotl/NoSessionsCreatedException.java @@ -0,0 +1,4 @@ +package eu.siacs.conversations.crypto.axolotl; + +public class NoSessionsCreatedException extends Throwable{ +} diff --git a/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java b/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java index b11670e4a..4b87fc5cb 100644 --- a/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java +++ b/src/main/java/eu/siacs/conversations/crypto/axolotl/XmppAxolotlMessage.java @@ -1,4 +1,184 @@ package eu.siacs.conversations.crypto.axolotl; +import android.util.Base64; + +import java.security.InvalidAlgorithmParameterException; +import java.security.NoSuchAlgorithmException; +import java.security.InvalidKeyException; +import java.util.HashSet; +import java.util.Set; + +import javax.crypto.BadPaddingException; +import javax.crypto.Cipher; +import javax.crypto.IllegalBlockSizeException; +import javax.crypto.KeyGenerator; +import javax.crypto.NoSuchPaddingException; +import javax.crypto.SecretKey; +import javax.crypto.spec.IvParameterSpec; +import javax.crypto.spec.SecretKeySpec; + +import eu.siacs.conversations.entities.Contact; +import eu.siacs.conversations.xml.Element; + public class XmppAxolotlMessage { + private byte[] innerKey; + private byte[] ciphertext; + private byte[] iv; + private final Set<XmppAxolotlMessageHeader> headers; + private final Contact contact; + private final int sourceDeviceId; + + public static class XmppAxolotlMessageHeader { + private final int recipientDeviceId; + private final byte[] content; + + public XmppAxolotlMessageHeader(int deviceId, byte[] content) { + this.recipientDeviceId = deviceId; + this.content = content; + } + + public XmppAxolotlMessageHeader(Element header) { + if("header".equals(header.getName())) { + this.recipientDeviceId = Integer.parseInt(header.getAttribute("rid")); + this.content = Base64.decode(header.getContent(),Base64.DEFAULT); + } else { + throw new IllegalArgumentException("Argument not a <header> Element!"); + } + } + + public int getRecipientDeviceId() { + return recipientDeviceId; + } + + public byte[] getContents() { + return content; + } + + public Element toXml() { + Element headerElement = new Element("header"); + // TODO: generate XML + headerElement.setAttribute("rid", getRecipientDeviceId()); + headerElement.setContent(Base64.encodeToString(getContents(), Base64.DEFAULT)); + return headerElement; + } + } + + public static class XmppAxolotlPlaintextMessage { + private final AxolotlService.XmppAxolotlSession session; + private final String plaintext; + + public XmppAxolotlPlaintextMessage(AxolotlService.XmppAxolotlSession session, String plaintext) { + this.session = session; + this.plaintext = plaintext; + } + + public String getPlaintext() { + return plaintext; + } + } + + public XmppAxolotlMessage(Contact contact, Element axolotlMessage) { + this.contact = contact; + this.sourceDeviceId = Integer.parseInt(axolotlMessage.getAttribute("id")); + this.headers = new HashSet<>(); + for(Element child:axolotlMessage.getChildren()) { + switch(child.getName()) { + case "header": + headers.add(new XmppAxolotlMessageHeader(child)); + break; + case "message": + iv = Base64.decode(child.getAttribute("iv"),Base64.DEFAULT); + ciphertext = Base64.decode(child.getContent(),Base64.DEFAULT); + break; + default: + break; + } + } + } + + public XmppAxolotlMessage(Contact contact, int sourceDeviceId, String plaintext) { + this.contact = contact; + this.sourceDeviceId = sourceDeviceId; + this.headers = new HashSet<>(); + this.encrypt(plaintext); + } + + private void encrypt(String plaintext) { + try { + KeyGenerator generator = KeyGenerator.getInstance("AES"); + generator.init(128); + SecretKey secretKey = generator.generateKey(); + Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding"); + cipher.init(Cipher.ENCRYPT_MODE, secretKey); + this.innerKey = secretKey.getEncoded(); + this.iv = cipher.getIV(); + this.ciphertext = cipher.doFinal(plaintext.getBytes()); + } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException + | IllegalBlockSizeException | BadPaddingException e) { + + } + } + + public Contact getContact() { + return this.contact; + } + + public int getSenderDeviceId() { + return sourceDeviceId; + } + + public byte[] getCiphertext() { + return ciphertext; + } + + public Set<XmppAxolotlMessageHeader> getHeaders() { + return headers; + } + + public void addHeader(XmppAxolotlMessageHeader header) { + headers.add(header); + } + + public byte[] getInnerKey(){ + return innerKey; + } + + public byte[] getIV() { + return this.iv; + } + + public Element toXml() { + // TODO: generate outer XML, add in header XML + Element message= new Element("axolotl_message", AxolotlService.PEP_PREFIX); + message.setAttribute("id", sourceDeviceId); + for(XmppAxolotlMessageHeader header: headers) { + message.addChild(header.toXml()); + } + Element payload = message.addChild("message"); + payload.setAttribute("iv",Base64.encodeToString(iv, Base64.DEFAULT)); + payload.setContent(Base64.encodeToString(ciphertext,Base64.DEFAULT)); + return message; + } + + + public XmppAxolotlPlaintextMessage decrypt(AxolotlService.XmppAxolotlSession session, byte[] key) { + XmppAxolotlPlaintextMessage plaintextMessage = null; + try { + + Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding"); + SecretKeySpec keySpec = new SecretKeySpec(key, "AES"); + IvParameterSpec ivSpec = new IvParameterSpec(iv); + + cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec); + + String plaintext = new String(cipher.doFinal(ciphertext)); + plaintextMessage = new XmppAxolotlPlaintextMessage(session, plaintext); + + } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException + | InvalidAlgorithmParameterException | IllegalBlockSizeException + | BadPaddingException e) { + throw new AssertionError(e); + } + return plaintextMessage; + } } |