From 708e4f87dcfd8799100fcdbe9f86cf9b9cfb0226 Mon Sep 17 00:00:00 2001
From: akwizgran <michael@briarproject.org>
Date: Fri, 19 Oct 2012 21:05:21 +0100
Subject: [PATCH] Fixed some bugs and cleaned up code in
TransportConnectionRecogniser.
---
.../TransportConnectionRecogniser.java | 95 +++++++++++--------
1 file changed, 55 insertions(+), 40 deletions(-)
diff --git a/components/net/sf/briar/transport/TransportConnectionRecogniser.java b/components/net/sf/briar/transport/TransportConnectionRecogniser.java
index 9ddaacfc28..d5bbb12dd0 100644
--- a/components/net/sf/briar/transport/TransportConnectionRecogniser.java
+++ b/components/net/sf/briar/transport/TransportConnectionRecogniser.java
@@ -26,7 +26,7 @@ class TransportConnectionRecogniser {
private final DatabaseComponent db;
private final TransportId transportId;
private final Map<Bytes, WindowContext> tagMap; // Locking: this
- private final Map<RemovalKey, RemovalContext> windowMap; // Locking: this
+ private final Map<RemovalKey, RemovalContext> removalMap; // Locking: this
TransportConnectionRecogniser(CryptoComponent crypto, DatabaseComponent db,
TransportId transportId) {
@@ -34,72 +34,87 @@ class TransportConnectionRecogniser {
this.db = db;
this.transportId = transportId;
tagMap = new HashMap<Bytes, WindowContext>();
- windowMap = new HashMap<RemovalKey, RemovalContext>();
+ removalMap = new HashMap<RemovalKey, RemovalContext>();
}
synchronized ConnectionContext acceptConnection(byte[] tag)
throws DbException {
WindowContext wctx = tagMap.remove(new Bytes(tag));
- if(wctx == null) return null;
- ConnectionWindow w = wctx.window;
+ if(wctx == null) return null; // The tag was not expected
+ ConnectionWindow window = wctx.window;
ConnectionContext ctx = wctx.context;
+ long period = wctx.period;
+ ContactId contactId = ctx.getContactId();
+ byte[] secret = ctx.getSecret();
long connection = ctx.getConnectionNumber();
+ boolean alice = ctx.getAlice();
+ // Update the connection window and the expected tags
Cipher cipher = crypto.getTagCipher();
- ErasableKey key = crypto.deriveTagKey(ctx.getSecret(), ctx.getAlice());
- byte[] changedTag = new byte[TAG_LENGTH];
- Bytes changedTagWrapper = new Bytes(changedTag);
- for(long conn : w.setSeen(connection)) {
- TagEncoder.encodeTag(changedTag, cipher, key, conn);
- WindowContext old;
- if(conn <= connection) old = tagMap.remove(changedTagWrapper);
- else old = tagMap.put(changedTagWrapper, wctx);
- assert old == null;
+ ErasableKey key = crypto.deriveTagKey(secret, alice);
+ for(long connection1 : window.setSeen(connection)) {
+ byte[] tag1 = new byte[TAG_LENGTH];
+ TagEncoder.encodeTag(tag1, cipher, key, connection1);
+ if(connection1 <= connection) {
+ WindowContext old = tagMap.remove(new Bytes(tag1));
+ assert old == null;
+ } else {
+ ConnectionContext ctx1 = new ConnectionContext(contactId,
+ transportId, tag1, secret, connection1, alice);
+ WindowContext wctx1 = new WindowContext(window, ctx1, period);
+ WindowContext old = tagMap.put(new Bytes(tag1), wctx1);
+ assert old == null;
+ }
}
key.erase();
- ContactId c = ctx.getContactId();
- long centre = w.getCentre();
- byte[] bitmap = w.getBitmap();
- db.setConnectionWindow(c, transportId, wctx.period, centre, bitmap);
- return wctx.context;
+ // Store the updated connection window in the DB
+ long centre = window.getCentre();
+ byte[] bitmap = window.getBitmap();
+ db.setConnectionWindow(contactId, transportId, period, centre, bitmap);
+ return ctx;
}
- synchronized void addWindow(ContactId c, long period, boolean alice,
+ synchronized void addWindow(ContactId contactId, long period, boolean alice,
byte[] secret, long centre, byte[] bitmap) throws DbException {
+ // Create the connection window and the expected tags
Cipher cipher = crypto.getTagCipher();
ErasableKey key = crypto.deriveTagKey(secret, alice);
- ConnectionWindow w = new ConnectionWindow(centre, bitmap);
- for(long conn : w.getUnseen()) {
+ ConnectionWindow window = new ConnectionWindow(centre, bitmap);
+ for(long connection : window.getUnseen()) {
byte[] tag = new byte[TAG_LENGTH];
- TagEncoder.encodeTag(tag, cipher, key, conn);
- ConnectionContext ctx = new ConnectionContext(c, transportId, tag,
- secret, conn, alice);
- WindowContext wctx = new WindowContext(w, ctx, period);
- tagMap.put(new Bytes(tag), wctx);
+ TagEncoder.encodeTag(tag, cipher, key, connection);
+ ConnectionContext ctx = new ConnectionContext(contactId,
+ transportId, tag, secret, connection, alice);
+ WindowContext wctx = new WindowContext(window, ctx, period);
+ WindowContext old = tagMap.put(new Bytes(tag), wctx);
+ assert old == null;
}
- db.setConnectionWindow(c, transportId, period, centre, bitmap);
- RemovalContext ctx = new RemovalContext(w, secret, alice);
- windowMap.put(new RemovalKey(c, period), ctx);
+ // Store the new connection window in the DB
+ db.setConnectionWindow(contactId, transportId, period, centre, bitmap);
+ // Create a removal context to remove the window when the key expires
+ RemovalContext rctx = new RemovalContext(window, secret, alice);
+ removalMap.put(new RemovalKey(contactId, period), rctx);
}
- synchronized void removeWindow(ContactId c, long period) {
- RemovalContext ctx = windowMap.remove(new RemovalKey(c, period));
- if(ctx == null) throw new IllegalArgumentException();
+ synchronized void removeWindow(ContactId contactId, long period) {
+ RemovalKey rk = new RemovalKey(contactId, period);
+ RemovalContext rctx = removalMap.remove(rk);
+ if(rctx == null) throw new IllegalArgumentException();
+ // Remove the expected tags
Cipher cipher = crypto.getTagCipher();
- ErasableKey key = crypto.deriveTagKey(ctx.secret, ctx.alice);
- byte[] removedTag = new byte[TAG_LENGTH];
- Bytes removedTagWrapper = new Bytes(removedTag);
- for(long conn : ctx.window.getUnseen()) {
- TagEncoder.encodeTag(removedTag, cipher, key, conn);
- WindowContext old = tagMap.remove(removedTagWrapper);
+ ErasableKey key = crypto.deriveTagKey(rctx.secret, rctx.alice);
+ byte[] tag = new byte[TAG_LENGTH];
+ for(long connection : rctx.window.getUnseen()) {
+ TagEncoder.encodeTag(tag, cipher, key, connection);
+ WindowContext old = tagMap.remove(new Bytes(tag));
assert old != null;
}
key.erase();
- ByteUtils.erase(ctx.secret);
+ ByteUtils.erase(rctx.secret);
}
synchronized void removeWindows(ContactId c) {
Collection<RemovalKey> keysToRemove = new ArrayList<RemovalKey>();
- for(RemovalKey k : windowMap.keySet()) {
+ for(RemovalKey k : removalMap.keySet()) {
if(k.contactId.equals(c)) keysToRemove.add(k);
}
for(RemovalKey k : keysToRemove) removeWindow(k.contactId, k.period);
--
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