Add transport keys for reintroduced contact.

briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeProtocolEngine.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.client.ContactGroupFactory;
 import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.PrivateKey;
@@ -449,31 +450,26 @@ class IntroduceeProtocolEngine
 				s.getRemote().acceptTimestamp);
 		if (timestamp == -1) throw new AssertionError();
 
-		Map<TransportId, KeySetId> keys = null;
+		ContactId contactId;
 		try {
-			contactManager.addContact(txn, s.getRemote().author,
+			contactId = contactManager.addContact(txn, s.getRemote().author,
 					localAuthor.getId(), false);
-
-			// Only add transport properties and keys when the contact was added
-			// This will be changed once we have a way to reset state for peers
-			// that were contacts already at some point in the past.
-			Contact c = contactManager.getContact(txn,
-					s.getRemote().author.getId(), localAuthor.getId());
-
-			// add the keys to the new contact
-			keys = keyManager.addRotationKeys(txn, c.getId(),
-					new SecretKey(s.getMasterKey()), timestamp,
-					s.getLocal().alice, false);
-
 			// add signed transport properties for the contact
-			transportPropertyManager.addRemoteProperties(txn, c.getId(),
+			transportPropertyManager.addRemoteProperties(txn, contactId,
 					s.getRemote().transportProperties);
 		} catch (ContactExistsException e) {
-			// Ignore this, because the other introducee might have deleted us.
+			// The other introducee might have deleted us and been
-			// So we still want updated transport properties
+			// reintroduced. In that case we can ignore the transport
-			// and new transport keys.
+			// properties, but we still want the new transport keys as the
+			// contact will no longer have the old keys
+			contactId = contactManager.getContact(txn,
+					s.getRemote().author.getId(), localAuthor.getId()).getId();
 		}
 
+		Map<TransportId, KeySetId> keys = keyManager.addRotationKeys(txn,
+				contactId, new SecretKey(s.getMasterKey()), timestamp,
+				s.getLocal().alice, false);
+
 		// send ACTIVATE message with a MAC
 		byte[] mac = crypto.activateMac(s);
 		long localTimestamp = getTimestampForInvisibleMessage(s);

briar-core/src/test/java/org/briarproject/briar/introduction/IntroductionIntegrationTest.java

@@ -1667,6 +1667,126 @@ public class IntroductionIntegrationTest
 		assertTrue(deleteMessages0From1(emptySet()).allDeleted());
 	}
 
+	@Test
+	public void testReintroductionAfterBothIntroduceesDeleteEachOther()
+			throws Exception {
+		addListeners(true, true);
+
+		// Introduce 1 to 2
+		makeIntroduction(true);
+		updateContactIdsFor1And2();
+
+		// Sync client versions and transport properties - this shows that
+		// 1 and 2 share a set of transport keys
+		sync1To2(1, true);
+		sync2To1(1, true);
+		sync1To2(2, true);
+		sync2To1(1, true);
+		ack1To2(1);
+
+		// Both introducees delete each other
+		contactManager1.removeContact(contactId2From1);
+		contactManager2.removeContact(contactId1From2);
+
+		// Introduce 1 to 2 again
+		makeIntroduction(true);
+		updateContactIdsFor1And2();
+
+		// Sync client versions and transport properties again
+		sync1To2(1, true);
+		sync2To1(1, true);
+		sync1To2(2, true);
+		sync2To1(1, true);
+		ack1To2(1);
+	}
+
+	@Test
+	public void testReintroductionAfterOneIntroduceeDeletesTheOther()
+			throws Exception {
+		addListeners(true, true);
+
+		// Introduce 1 to 2
+		makeIntroduction(true);
+		updateContactIdsFor1And2();
+
+		// Sync client versions and transport properties - this shows that
+		// 1 and 2 share a set of transport keys
+		sync1To2(1, true);
+		sync2To1(1, true);
+		sync1To2(2, true);
+		sync2To1(1, true);
+		ack1To2(1);
+
+		// 1 deletes 2, but not vice versa
+		contactManager1.removeContact(contactId2From1);
+
+		// Introduce 1 to 2 again
+		makeIntroduction(false);
+		updateContactIdsFor1And2();
+
+		// Sync client versioning update from 1 to 2 only - this shows that
+		// although 1 and 2 share transport keys, the connection won't be
+		// fully functional until we have a way for 1 to reset the state it's
+		// holding about 2
+		sync1To2(1, true);
+		ack2To1(1);
+	}
+
+	private void makeIntroduction(boolean expectAddContact2From1)
+			throws Exception {
+		// Make introduction
+		Contact introducee1 = contact1From0;
+		Contact introducee2 = contact2From0;
+		introductionManager0.makeIntroduction(introducee1, introducee2, "Hi!");
+
+		// Request to 1
+		sync0To1(1, true);
+		eventWaiter.await(TIMEOUT, 1);
+		assertTrue(listener1.requestReceived);
+
+		// Request to 2
+		sync0To2(1, true);
+		eventWaiter.await(TIMEOUT, 1);
+		assertTrue(listener2.requestReceived);
+
+		// Response from 1, forwarded
+		sync1To0(1, true);
+		eventWaiter.await(TIMEOUT, 1);
+		assertTrue(listener0.response1Received);
+		sync0To2(1, true);
+
+		// Response and auth from 2, forwarded
+		sync2To0(2, true);
+		eventWaiter.await(TIMEOUT, 1);
+		assertTrue(listener0.response2Received);
+		sync0To1(2, true);
+		if (expectAddContact2From1) {
+			eventWaiter.await(TIMEOUT, 1);
+			assertTrue(listener1.succeeded);
+		}
+		assertTrue(contactManager1
+				.contactExists(author2.getId(), author1.getId()));
+
+		// Auth and activate from 1, forwarded
+		sync1To0(2, true);
+		sync0To2(2, true);
+		eventWaiter.await(TIMEOUT, 1);
+		assertTrue(listener2.succeeded);
+		assertTrue(contactManager2
+				.contactExists(author1.getId(), author2.getId()));
+
+		// Activate from 2, forwarded
+		sync2To0(1, true);
+		sync0To1(1, true);
+	}
+
+	private void updateContactIdsFor1And2() throws Exception {
+		contactId2From1 = contactManager1.getContact(author2.getId(),
+				author1.getId()).getId();
+		contactId1From2 = contactManager2.getContact(author1.getId(),
+				author2.getId()).getId();
+	}
+
 	private DeletionResult deleteAllMessages1From0() throws DbException {
 		return db0.transactionWithResult(false, txn -> introductionManager0
 				.deleteAllMessages(txn, contactId1From0));