Author: nextgens
Date: 2007-09-09 21:04:47 +0000 (Sun, 09 Sep 2007)
New Revision: 15093
Modified:
branches/freenet-jfk/src/freenet/node/FNPPacketMangler.java
Log:
Fix a serious bug I've introduced ... The key of the mac isn't supposed to be
g^r !
Modified: branches/freenet-jfk/src/freenet/node/FNPPacketMangler.java
===================================================================
--- branches/freenet-jfk/src/freenet/node/FNPPacketMangler.java 2007-09-09
20:44:41 UTC (rev 15092)
+++ branches/freenet-jfk/src/freenet/node/FNPPacketMangler.java 2007-09-09
21:04:47 UTC (rev 15093)
@@ -75,15 +75,17 @@
*/
final Map message3Cache;
final Map message4Cache;
- final HashMap authenticatorCache;
+ private byte[] transitentKey = null;
+ private final HashMap authenticatorCache;
final eKey encryptionKey;
final DSAGroup g;
static DSAPrivateKey PKR,PKI;
final RandomSource r;
/** We renew it on each *successful* run of the protocol (the spec.
says "once a while") - access is synchronized! */
private DiffieHellmanLightContext currentDHContext = null;
+ private static final int TRANSITENT_KEY_SIZE = 12;
// TODO: is 64 bits enough ?
- public static final int NONCE_SIZE = 6;
+ private static final int NONCE_SIZE = 6;
private static final int MAX_PACKETS_IN_FLIGHT = 256;
private static final int RANDOM_BYTES_LENGTH = 12;
private static final int HASH_LENGTH = SHA256.getDigestLength();
@@ -588,7 +590,7 @@
// FIXME: SHA1 or SHA256 there ? does it matter ?
HMAC hash = new HMAC(SHA1.getInstance());
// TODO: is that 512 LSB ?
- return hash.mac(gR, authData, 9);
+ return hash.mac(getTransitentKey(), authData, 9);
}
/*
* Hash the authenticator using SHA256
@@ -2216,8 +2218,28 @@
}
private synchronized DiffieHellmanLightContext
getLightDiffieHellmanContext() {
- if(currentDHContext == null){
+ if(currentDHContext == null)
currentDHContext = DiffieHellman.generateLightContext();
return currentDHContext;
}
-}
+
+ private byte[] getTransitentKey() {
+ synchronized (authenticatorCache) {
+ if(transitentKey == null){
+ transitentKey = new byte[TRANSITENT_KEY_SIZE];
+ node.random.nextBytes(transitentKey);
+
+ // reset the authenticator cache
+ authenticatorCache.clear();
+ }
+ return transitentKey;
+ }
+ }
+
+ //TODO: when shall that be called ? what about DH exponentials ?
+ private void resetTransitentKey() {
+ synchronized (authenticatorCache) {
+ transitentKey = null;
+ }
+ }
+}
\ No newline at end of file
