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Fixed some bugs and cleaned up code in TransportConnectionRecogniser.

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This commit is contained in:
akwizgran
2012-10-19 21:05:21 +01:00
parent 79c3ef572d
commit 708e4f87dc
1 changed files with 62 additions and 47 deletions
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109
components/net/sf/briar/transport/TransportConnectionRecogniser.java
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@@ -26,7 +26,7 @@ class TransportConnectionRecogniser {
private final DatabaseComponent db; private final DatabaseComponent db;
private final TransportId transportId; private final TransportId transportId;
private final Map<Bytes, WindowContext> tagMap; // Locking: this 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, TransportConnectionRecogniser(CryptoComponent crypto, DatabaseComponent db,
TransportId transportId) { TransportId transportId) {
@@ -34,72 +34,87 @@ class TransportConnectionRecogniser {
this.db = db; this.db = db;
this.transportId = transportId; this.transportId = transportId;
tagMap = new HashMap<Bytes, WindowContext>(); tagMap = new HashMap<Bytes, WindowContext>();
windowMap = new HashMap<RemovalKey, RemovalContext>(); removalMap = new HashMap<RemovalKey, RemovalContext>();
} }
synchronized ConnectionContext acceptConnection(byte[] tag) synchronized ConnectionContext acceptConnection(byte[] tag)
throws DbException { throws DbException {
WindowContext wctx = tagMap.remove(new Bytes(tag)); WindowContext wctx = tagMap.remove(new Bytes(tag));
if(wctx == null) return null; if(wctx == null) return null; // The tag was not expected
ConnectionWindow w = wctx.window; ConnectionWindow window = wctx.window;
ConnectionContext ctx = wctx.context; ConnectionContext ctx = wctx.context;
long period = wctx.period;
ContactId contactId = ctx.getContactId();
byte[] secret = ctx.getSecret();
long connection = ctx.getConnectionNumber(); long connection = ctx.getConnectionNumber();
Cipher cipher = crypto.getTagCipher(); boolean alice = ctx.getAlice();
ErasableKey key = crypto.deriveTagKey(ctx.getSecret(), ctx.getAlice()); // Update the connection window and the expected tags
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;
}
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;
}
synchronized void addWindow(ContactId c, long period, boolean alice,
byte[] secret, long centre, byte[] bitmap) throws DbException {
Cipher cipher = crypto.getTagCipher(); Cipher cipher = crypto.getTagCipher();
ErasableKey key = crypto.deriveTagKey(secret, alice); ErasableKey key = crypto.deriveTagKey(secret, alice);
ConnectionWindow w = new ConnectionWindow(centre, bitmap); for(long connection1 : window.setSeen(connection)) {
for(long conn : w.getUnseen()) { byte[] tag1 = new byte[TAG_LENGTH];
byte[] tag = new byte[TAG_LENGTH]; TagEncoder.encodeTag(tag1, cipher, key, connection1);
TagEncoder.encodeTag(tag, cipher, key, conn); if(connection1 <= connection) {
ConnectionContext ctx = new ConnectionContext(c, transportId, tag, WindowContext old = tagMap.remove(new Bytes(tag1));
secret, conn, alice); assert old == null;
WindowContext wctx = new WindowContext(w, ctx, period); } else {
tagMap.put(new Bytes(tag), wctx); 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;
}
} }
db.setConnectionWindow(c, transportId, period, centre, bitmap); key.erase();
RemovalContext ctx = new RemovalContext(w, secret, alice); // Store the updated connection window in the DB
windowMap.put(new RemovalKey(c, period), ctx); long centre = window.getCentre();
byte[] bitmap = window.getBitmap();
db.setConnectionWindow(contactId, transportId, period, centre, bitmap);
return ctx;
} }
synchronized void removeWindow(ContactId c, long period) { synchronized void addWindow(ContactId contactId, long period, boolean alice,
RemovalContext ctx = windowMap.remove(new RemovalKey(c, period)); byte[] secret, long centre, byte[] bitmap) throws DbException {
if(ctx == null) throw new IllegalArgumentException(); // Create the connection window and the expected tags
Cipher cipher = crypto.getTagCipher(); Cipher cipher = crypto.getTagCipher();
ErasableKey key = crypto.deriveTagKey(ctx.secret, ctx.alice); ErasableKey key = crypto.deriveTagKey(secret, alice);
byte[] removedTag = new byte[TAG_LENGTH]; ConnectionWindow window = new ConnectionWindow(centre, bitmap);
Bytes removedTagWrapper = new Bytes(removedTag); for(long connection : window.getUnseen()) {
for(long conn : ctx.window.getUnseen()) { byte[] tag = new byte[TAG_LENGTH];
TagEncoder.encodeTag(removedTag, cipher, key, conn); TagEncoder.encodeTag(tag, cipher, key, connection);
WindowContext old = tagMap.remove(removedTagWrapper); 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;
}
// 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 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(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; assert old != null;
} }
key.erase(); key.erase();
ByteUtils.erase(ctx.secret); ByteUtils.erase(rctx.secret);
} }
synchronized void removeWindows(ContactId c) { synchronized void removeWindows(ContactId c) {
Collection<RemovalKey> keysToRemove = new ArrayList<RemovalKey>(); Collection<RemovalKey> keysToRemove = new ArrayList<RemovalKey>();
for(RemovalKey k : windowMap.keySet()) { for(RemovalKey k : removalMap.keySet()) {
if(k.contactId.equals(c)) keysToRemove.add(k); if(k.contactId.equals(c)) keysToRemove.add(k);
} }
for(RemovalKey k : keysToRemove) removeWindow(k.contactId, k.period); for(RemovalKey k : keysToRemove) removeWindow(k.contactId, k.period);