From 701cfdba4820b560999803a2ceeee2ba78a5414e Mon Sep 17 00:00:00 2001
From: str4d <str4d@mail.i2p>
Date: Thu, 25 Feb 2016 22:01:15 +0000
Subject: [PATCH] Extract contact exchange protocol from BT introduction
protocol
---
.../api/contact/ContactExchangeListener.java | 14 +
.../api/contact/ContactExchangeTask.java | 20 ++
.../api/crypto/CryptoComponent.java | 2 +-
.../contact/ContactExchangeTaskImpl.java | 253 ++++++++++++++++++
.../briarproject/contact/ContactModule.java | 24 ++
.../crypto/CryptoComponentImpl.java | 2 +-
.../invitation/AliceConnector.java | 4 +-
.../briarproject/invitation/BobConnector.java | 4 +-
8 files changed, 317 insertions(+), 6 deletions(-)
create mode 100644 briar-api/src/org/briarproject/api/contact/ContactExchangeListener.java
create mode 100644 briar-api/src/org/briarproject/api/contact/ContactExchangeTask.java
create mode 100644 briar-core/src/org/briarproject/contact/ContactExchangeTaskImpl.java
diff --git a/briar-api/src/org/briarproject/api/contact/ContactExchangeListener.java b/briar-api/src/org/briarproject/api/contact/ContactExchangeListener.java
new file mode 100644
index 0000000000..50bf543c71
--- /dev/null
+++ b/briar-api/src/org/briarproject/api/contact/ContactExchangeListener.java
@@ -0,0 +1,14 @@
+package org.briarproject.api.contact;
+
+import org.briarproject.api.identity.Author;
+
+public interface ContactExchangeListener {
+
+ void contactExchangeSucceeded(Author remoteAuthor);
+
+ /** The exchange failed because the contact already exists. */
+ void duplicateContact(Author remoteAuthor);
+
+ /** A general failure. */
+ void contactExchangeFailed();
+}
diff --git a/briar-api/src/org/briarproject/api/contact/ContactExchangeTask.java b/briar-api/src/org/briarproject/api/contact/ContactExchangeTask.java
new file mode 100644
index 0000000000..fe00530903
--- /dev/null
+++ b/briar-api/src/org/briarproject/api/contact/ContactExchangeTask.java
@@ -0,0 +1,20 @@
+package org.briarproject.api.contact;
+
+import org.briarproject.api.TransportId;
+import org.briarproject.api.crypto.SecretKey;
+import org.briarproject.api.identity.LocalAuthor;
+import org.briarproject.api.plugins.duplex.DuplexTransportConnection;
+
+/**
+ * A task for conducting a contact information exchange with a remote peer.
+ */
+public interface ContactExchangeTask {
+
+ /**
+ * Exchange contact information with a remote peer.
+ */
+ void startExchange(ContactExchangeListener listener,
+ LocalAuthor localAuthor, SecretKey masterSecret,
+ DuplexTransportConnection conn, TransportId transportId,
+ boolean alice, boolean reuseConnection);
+}
diff --git a/briar-api/src/org/briarproject/api/crypto/CryptoComponent.java b/briar-api/src/org/briarproject/api/crypto/CryptoComponent.java
index 0ba779202b..8ffd06213e 100644
--- a/briar-api/src/org/briarproject/api/crypto/CryptoComponent.java
+++ b/briar-api/src/org/briarproject/api/crypto/CryptoComponent.java
@@ -47,7 +47,7 @@ public interface CryptoComponent {
* sign.
* @param alice whether the nonce is for use by Alice or Bob.
*/
- byte[] deriveBTSignatureNonce(SecretKey master, boolean alice);
+ byte[] deriveSignatureNonce(SecretKey master, boolean alice);
/**
* Derives a commitment to the provided public key.
diff --git a/briar-core/src/org/briarproject/contact/ContactExchangeTaskImpl.java b/briar-core/src/org/briarproject/contact/ContactExchangeTaskImpl.java
new file mode 100644
index 0000000000..53f0fab7b0
--- /dev/null
+++ b/briar-core/src/org/briarproject/contact/ContactExchangeTaskImpl.java
@@ -0,0 +1,253 @@
+package org.briarproject.contact;
+
+import org.briarproject.api.FormatException;
+import org.briarproject.api.TransportId;
+import org.briarproject.api.contact.ContactExchangeListener;
+import org.briarproject.api.contact.ContactExchangeTask;
+import org.briarproject.api.contact.ContactId;
+import org.briarproject.api.contact.ContactManager;
+import org.briarproject.api.crypto.CryptoComponent;
+import org.briarproject.api.crypto.KeyParser;
+import org.briarproject.api.crypto.SecretKey;
+import org.briarproject.api.crypto.Signature;
+import org.briarproject.api.data.BdfReader;
+import org.briarproject.api.data.BdfReaderFactory;
+import org.briarproject.api.data.BdfWriter;
+import org.briarproject.api.data.BdfWriterFactory;
+import org.briarproject.api.db.ContactExistsException;
+import org.briarproject.api.db.DbException;
+import org.briarproject.api.identity.Author;
+import org.briarproject.api.identity.AuthorFactory;
+import org.briarproject.api.identity.LocalAuthor;
+import org.briarproject.api.plugins.ConnectionManager;
+import org.briarproject.api.plugins.duplex.DuplexTransportConnection;
+import org.briarproject.api.system.Clock;
+import org.briarproject.api.transport.KeyManager;
+import org.briarproject.api.transport.StreamReaderFactory;
+import org.briarproject.api.transport.StreamWriterFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.security.GeneralSecurityException;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
+import static org.briarproject.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
+import static org.briarproject.api.identity.AuthorConstants.MAX_SIGNATURE_LENGTH;
+
+public class ContactExchangeTaskImpl extends Thread
+ implements ContactExchangeTask {
+
+ private static final Logger LOG =
+ Logger.getLogger(ContactExchangeTaskImpl.class.getName());
+
+ private final AuthorFactory authorFactory;
+ private final BdfReaderFactory bdfReaderFactory;
+ private final BdfWriterFactory bdfWriterFactory;
+ private final Clock clock;
+ private final ConnectionManager connectionManager;
+ private final ContactManager contactManager;
+ private final CryptoComponent crypto;
+ private final KeyManager keyManager;
+ private final StreamReaderFactory streamReaderFactory;
+ private final StreamWriterFactory streamWriterFactory;
+
+ private ContactExchangeListener listener;
+ private LocalAuthor localAuthor;
+ private DuplexTransportConnection conn;
+ private TransportId transportId;
+ private SecretKey masterSecret;
+ private boolean alice;
+ private boolean reuseConnection;
+
+ public ContactExchangeTaskImpl(AuthorFactory authorFactory,
+ BdfReaderFactory bdfReaderFactory,
+ BdfWriterFactory bdfWriterFactory, Clock clock,
+ ConnectionManager connectionManager, ContactManager contactManager,
+ CryptoComponent crypto, KeyManager keyManager,
+ StreamReaderFactory streamReaderFactory,
+ StreamWriterFactory streamWriterFactory) {
+ this.authorFactory = authorFactory;
+ this.bdfReaderFactory = bdfReaderFactory;
+ this.bdfWriterFactory = bdfWriterFactory;
+ this.clock = clock;
+ this.connectionManager = connectionManager;
+ this.contactManager = contactManager;
+ this.crypto = crypto;
+ this.keyManager = keyManager;
+ this.streamReaderFactory = streamReaderFactory;
+ this.streamWriterFactory = streamWriterFactory;
+ }
+
+ @Override
+ public void startExchange(ContactExchangeListener listener,
+ LocalAuthor localAuthor, SecretKey masterSecret,
+ DuplexTransportConnection conn, TransportId transportId,
+ boolean alice, boolean reuseConnection) {
+ this.listener = listener;
+ this.localAuthor = localAuthor;
+ this.conn = conn;
+ this.transportId = transportId;
+ this.masterSecret = masterSecret;
+ this.alice = alice;
+ this.reuseConnection = reuseConnection;
+ start();
+ }
+
+ @Override
+ public void run() {
+ BdfReader r;
+ BdfWriter w;
+ try {
+ // Create the readers
+ InputStream streamReader =
+ streamReaderFactory.createInvitationStreamReader(
+ conn.getReader().getInputStream(),
+ masterSecret);
+ r = bdfReaderFactory.createReader(streamReader);
+ // Create the writers
+ OutputStream streamWriter =
+ streamWriterFactory.createInvitationStreamWriter(
+ conn.getWriter().getOutputStream(),
+ masterSecret);
+ w = bdfWriterFactory.createWriter(streamWriter);
+ } catch (IOException e) {
+ if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+ listener.contactExchangeFailed();
+ tryToClose(conn, true);
+ return;
+ }
+
+ // Derive the invitation nonces
+ byte[] aliceNonce = crypto.deriveSignatureNonce(masterSecret, true);
+ byte[] bobNonce = crypto.deriveSignatureNonce(masterSecret, false);
+
+ // Exchange pseudonyms, signed nonces, and timestamps
+ long localTimestamp = clock.currentTimeMillis();
+ Author remoteAuthor;
+ long remoteTimestamp;
+ try {
+ if (alice) {
+ sendPseudonym(w, aliceNonce);
+ sendTimestamp(w, localTimestamp);
+ remoteAuthor = receivePseudonym(r, bobNonce);
+ remoteTimestamp = receiveTimestamp(r);
+ } else {
+ remoteAuthor = receivePseudonym(r, aliceNonce);
+ remoteTimestamp = receiveTimestamp(r);
+ sendPseudonym(w, bobNonce);
+ sendTimestamp(w, localTimestamp);
+ }
+ // Close the outgoing stream and expect EOF on the incoming stream
+ w.close();
+ if (!r.eof()) LOG.warning("Unexpected data at end of connection");
+ } catch (GeneralSecurityException e) {
+ if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+ listener.contactExchangeFailed();
+ tryToClose(conn, true);
+ return;
+ } catch (IOException e) {
+ if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+ listener.contactExchangeFailed();
+ tryToClose(conn, true);
+ return;
+ }
+
+ // The agreed timestamp is the minimum of the peers' timestamps
+ long timestamp = Math.min(localTimestamp, remoteTimestamp);
+
+ try {
+ // Add the contact
+ ContactId contactId =
+ addContact(remoteAuthor, masterSecret, timestamp, true);
+ // Reuse the connection as a transport connection
+ if (reuseConnection)
+ connectionManager
+ .manageOutgoingConnection(contactId, transportId, conn);
+ // Pseudonym exchange succeeded
+ LOG.info("Pseudonym exchange succeeded");
+ listener.contactExchangeSucceeded(remoteAuthor);
+ } catch (ContactExistsException e) {
+ if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+ tryToClose(conn, true);
+ listener.duplicateContact(remoteAuthor);
+ } catch (DbException e) {
+ if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+ tryToClose(conn, true);
+ listener.contactExchangeFailed();
+ }
+ }
+
+ private void sendPseudonym(BdfWriter w, byte[] nonce)
+ throws GeneralSecurityException, IOException {
+ // Sign the nonce
+ Signature signature = crypto.getSignature();
+ KeyParser keyParser = crypto.getSignatureKeyParser();
+ byte[] privateKey = localAuthor.getPrivateKey();
+ signature.initSign(keyParser.parsePrivateKey(privateKey));
+ signature.update(nonce);
+ byte[] sig = signature.sign();
+ // Write the name, public key and signature
+ w.writeString(localAuthor.getName());
+ w.writeRaw(localAuthor.getPublicKey());
+ w.writeRaw(sig);
+ w.flush();
+ LOG.info("Sent pseudonym");
+ }
+
+ private Author receivePseudonym(BdfReader r, byte[] nonce)
+ throws GeneralSecurityException, IOException {
+ // Read the name, public key and signature
+ String name = r.readString(MAX_AUTHOR_NAME_LENGTH);
+ byte[] publicKey = r.readRaw(MAX_PUBLIC_KEY_LENGTH);
+ byte[] sig = r.readRaw(MAX_SIGNATURE_LENGTH);
+ LOG.info("Received pseudonym");
+ // Verify the signature
+ Signature signature = crypto.getSignature();
+ KeyParser keyParser = crypto.getSignatureKeyParser();
+ signature.initVerify(keyParser.parsePublicKey(publicKey));
+ signature.update(nonce);
+ if (!signature.verify(sig)) {
+ if (LOG.isLoggable(INFO))
+ LOG.info("Invalid signature");
+ throw new GeneralSecurityException();
+ }
+ return authorFactory.createAuthor(name, publicKey);
+ }
+
+ private void sendTimestamp(BdfWriter w, long timestamp)
+ throws IOException {
+ w.writeLong(timestamp);
+ w.flush();
+ LOG.info("Sent timestamp");
+ }
+
+ private long receiveTimestamp(BdfReader r) throws IOException {
+ long timestamp = r.readLong();
+ if (timestamp < 0) throw new FormatException();
+ LOG.info("Received timestamp");
+ return timestamp;
+ }
+
+ private ContactId addContact(Author remoteAuthor, SecretKey master,
+ long timestamp, boolean alice) throws DbException {
+ // Add the contact to the database
+ ContactId contactId = contactManager.addContact(remoteAuthor,
+ localAuthor.getId(), master, timestamp, alice, true);
+ return contactId;
+ }
+
+ private void tryToClose(DuplexTransportConnection conn,
+ boolean exception) {
+ try {
+ LOG.info("Closing connection");
+ conn.getReader().dispose(exception, true);
+ conn.getWriter().dispose(exception);
+ } catch (IOException e) {
+ if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+ }
+ }
+}
diff --git a/briar-core/src/org/briarproject/contact/ContactModule.java b/briar-core/src/org/briarproject/contact/ContactModule.java
index bd8e2d3afa..77da9366fc 100644
--- a/briar-core/src/org/briarproject/contact/ContactModule.java
+++ b/briar-core/src/org/briarproject/contact/ContactModule.java
@@ -1,8 +1,18 @@
package org.briarproject.contact;
+import org.briarproject.api.contact.ContactExchangeTask;
import org.briarproject.api.contact.ContactManager;
+import org.briarproject.api.crypto.CryptoComponent;
+import org.briarproject.api.data.BdfReaderFactory;
+import org.briarproject.api.data.BdfWriterFactory;
+import org.briarproject.api.identity.AuthorFactory;
import org.briarproject.api.identity.IdentityManager;
import org.briarproject.api.lifecycle.LifecycleManager;
+import org.briarproject.api.plugins.ConnectionManager;
+import org.briarproject.api.system.Clock;
+import org.briarproject.api.transport.KeyManager;
+import org.briarproject.api.transport.StreamReaderFactory;
+import org.briarproject.api.transport.StreamWriterFactory;
import javax.inject.Inject;
import javax.inject.Singleton;
@@ -25,4 +35,18 @@ public class ContactModule {
identityManager.registerRemoveIdentityHook(contactManager);
return contactManager;
}
+
+ @Provides
+ ContactExchangeTask provideContactExchangeTask(
+ AuthorFactory authorFactory, BdfReaderFactory bdfReaderFactory,
+ BdfWriterFactory bdfWriterFactory, Clock clock,
+ ConnectionManager connectionManager, ContactManager contactManager,
+ CryptoComponent crypto, KeyManager keyManager,
+ StreamReaderFactory streamReaderFactory,
+ StreamWriterFactory streamWriterFactory) {
+ return new ContactExchangeTaskImpl(authorFactory,
+ bdfReaderFactory, bdfWriterFactory, clock, connectionManager,
+ contactManager, crypto, keyManager, streamReaderFactory,
+ streamWriterFactory);
+ }
}
diff --git a/briar-core/src/org/briarproject/crypto/CryptoComponentImpl.java b/briar-core/src/org/briarproject/crypto/CryptoComponentImpl.java
index 2a779f3fe2..c17f679010 100644
--- a/briar-core/src/org/briarproject/crypto/CryptoComponentImpl.java
+++ b/briar-core/src/org/briarproject/crypto/CryptoComponentImpl.java
@@ -214,7 +214,7 @@ class CryptoComponentImpl implements CryptoComponent {
return new SecretKey(macKdf(master, alice ? BT_A_INVITE : BT_B_INVITE));
}
- public byte[] deriveBTSignatureNonce(SecretKey master, boolean alice) {
+ public byte[] deriveSignatureNonce(SecretKey master, boolean alice) {
return macKdf(master, alice ? BT_A_NONCE : BT_B_NONCE);
}
diff --git a/briar-core/src/org/briarproject/invitation/AliceConnector.java b/briar-core/src/org/briarproject/invitation/AliceConnector.java
index 210d173d9e..fc02774043 100644
--- a/briar-core/src/org/briarproject/invitation/AliceConnector.java
+++ b/briar-core/src/org/briarproject/invitation/AliceConnector.java
@@ -138,8 +138,8 @@ class AliceConnector extends Connector {
aliceHeaderKey);
w = bdfWriterFactory.createWriter(streamWriter);
// Derive the invitation nonces
- byte[] aliceNonce = crypto.deriveBTSignatureNonce(master, true);
- byte[] bobNonce = crypto.deriveBTSignatureNonce(master, false);
+ byte[] aliceNonce = crypto.deriveSignatureNonce(master, true);
+ byte[] bobNonce = crypto.deriveSignatureNonce(master, false);
// Exchange pseudonyms, signed nonces, and timestamps
Author remoteAuthor;
long remoteTimestamp;
diff --git a/briar-core/src/org/briarproject/invitation/BobConnector.java b/briar-core/src/org/briarproject/invitation/BobConnector.java
index f2c6e26196..2f1cfc2e8d 100644
--- a/briar-core/src/org/briarproject/invitation/BobConnector.java
+++ b/briar-core/src/org/briarproject/invitation/BobConnector.java
@@ -138,8 +138,8 @@ class BobConnector extends Connector {
bobHeaderKey);
w = bdfWriterFactory.createWriter(streamWriter);
// Derive the nonces
- byte[] aliceNonce = crypto.deriveBTSignatureNonce(master, true);
- byte[] bobNonce = crypto.deriveBTSignatureNonce(master, false);
+ byte[] aliceNonce = crypto.deriveSignatureNonce(master, true);
+ byte[] bobNonce = crypto.deriveSignatureNonce(master, false);
// Exchange pseudonyms, signed nonces and timestamps
Author remoteAuthor;
long remoteTimestamp;
--
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