From 69fac86a0cb74c2980576025eb0fec29ec28d2be Mon Sep 17 00:00:00 2001
From: akwizgran <michael@briarproject.org>
Date: Mon, 5 Jul 2021 18:02:22 +0100
Subject: [PATCH] Clear keys from session when moving to AWAIT_ACTIVATE state.

---
 .../IntroduceeProtocolEngine.java             |  3 +-
 .../briar/introduction/IntroduceeSession.java | 31 ++++++++++++++-----
 .../IntroduceeProtocolEngineTest.java         |  6 ++++
 3 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeProtocolEngine.java b/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeProtocolEngine.java
index d198a3bd3..03372d6c8 100644
--- a/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeProtocolEngine.java
+++ b/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeProtocolEngine.java
@@ -49,6 +49,7 @@ import javax.inject.Inject;
 
 import static java.lang.Math.max;
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.api.system.Clock.MIN_REASONABLE_TIME_MS;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.introduction.IntroduceeState.AWAIT_AUTH;
@@ -476,7 +477,7 @@ class IntroduceeProtocolEngine
 
 			// add signed transport properties for the contact
 			transportPropertyManager.addRemoteProperties(txn, contactId,
-					s.getRemote().transportProperties);
+					requireNonNull(s.getRemote().transportProperties));
 		} catch (ContactExistsException e) {
 			// Ignore this, because the other introducee might have deleted us
 		}
diff --git a/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeSession.java b/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeSession.java
index 13fd4df0f..80f9d95b3 100644
--- a/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeSession.java
+++ b/briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeSession.java
@@ -116,8 +116,8 @@ class IntroduceeSession extends Session<IntroduceeState>
 
 	static IntroduceeSession awaitActivate(IntroduceeSession s, AuthMessage m,
 			Message sent, @Nullable Map<TransportId, KeySetId> transportKeys) {
-		Local local = new Local(s.local, sent.getId(), sent.getTimestamp());
-		Remote remote = new Remote(s.remote, m.getMessageId());
+		Local local = Local.clear(s.local, sent.getId(), sent.getTimestamp());
+		Remote remote = Remote.clear(s.remote, m.getMessageId());
 		return new IntroduceeSession(s.getSessionId(), AWAIT_ACTIVATE,
 				s.getRequestTimestamp(), s.contactGroupId, s.introducer, local,
 				remote, null, transportKeys);
@@ -228,11 +228,15 @@ class IntroduceeSession extends Session<IntroduceeState>
 			this.ephemeralPrivateKey = ephemeralPrivateKey;
 		}
 
-		private Local(Local s, @Nullable MessageId lastMessageId,
-				long lastMessageTimestamp) {
-			this(s.alice, lastMessageId, lastMessageTimestamp,
-					s.ephemeralPublicKey, s.ephemeralPrivateKey,
-					s.transportProperties, s.acceptTimestamp, s.macKey);
+		/**
+		 * Returns a copy of the given Local, updating the last message ID
+		 * and timestamp and clearing the ephemeral keys.
+		 */
+		private static Local clear(Local s,
+				@Nullable MessageId lastMessageId, long lastMessageTimestamp) {
+			return new Local(s.alice, lastMessageId, lastMessageTimestamp,
+					null, null, s.transportProperties, s.acceptTimestamp,
+					s.macKey);
 		}
 	}
 
@@ -249,10 +253,23 @@ class IntroduceeSession extends Session<IntroduceeState>
 			this.author = author;
 		}
 
+		/**
+		 * Returns a copy of the given Remote, updating the last message ID.
+		 */
 		private Remote(Remote s, @Nullable MessageId lastMessageId) {
 			this(s.alice, s.author, lastMessageId, s.ephemeralPublicKey,
 					s.transportProperties, s.acceptTimestamp, s.macKey);
 		}
+
+		/**
+		 * Returns a copy of the given Remote, updating the last message ID
+		 * and clearing the ephemeral keys.
+		 */
+		private static Remote clear(Remote s,
+				@Nullable MessageId lastMessageId) {
+			return new Remote(s.alice, s.author, lastMessageId, null,
+					s.transportProperties, s.acceptTimestamp, s.macKey);
+		}
 	}
 
 }
diff --git a/briar-core/src/test/java/org/briarproject/briar/introduction/IntroduceeProtocolEngineTest.java b/briar-core/src/test/java/org/briarproject/briar/introduction/IntroduceeProtocolEngineTest.java
index b78817352..ab2d1cc36 100644
--- a/briar-core/src/test/java/org/briarproject/briar/introduction/IntroduceeProtocolEngineTest.java
+++ b/briar-core/src/test/java/org/briarproject/briar/introduction/IntroduceeProtocolEngineTest.java
@@ -54,6 +54,7 @@ import static org.briarproject.briar.introduction.IntroduceeState.AWAIT_AUTH;
 import static org.briarproject.briar.introduction.IntroduceeState.START;
 import static org.briarproject.briar.introduction.MessageType.ABORT;
 import static org.briarproject.briar.introduction.MessageType.ACTIVATE;
+import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 
@@ -176,9 +177,14 @@ public class IntroduceeProtocolEngineTest extends BrambleMockTestCase {
 		IntroduceeSession.Local afterLocal = after.getLocal();
 		assertEquals(activateMessage.getId(), afterLocal.lastMessageId);
 		assertEquals(now, afterLocal.lastMessageTimestamp);
+		assertNull(afterLocal.ephemeralPublicKey);
+		assertNull(afterLocal.ephemeralPrivateKey);
+		assertArrayEquals(localMacKey.getBytes(), afterLocal.macKey);
 
 		IntroduceeSession.Remote afterRemote = after.getRemote();
 		assertEquals(authMessage.getMessageId(), afterRemote.lastMessageId);
+		assertNull(afterRemote.ephemeralPublicKey);
+		assertArrayEquals(remoteMacKey.getBytes(), afterRemote.macKey);
 	}
 
 	@Test