Examples with EncryptedBuildRecord net.i2p.data.i2np.EncryptedBuildRecord used on opensource projects

Example 1 with EncryptedBuildRecord

use of net.i2p.data.i2np.EncryptedBuildRecord in project i2p.i2p by i2p.

the class BuildHandler method handleReq.

/**
 * If we are dropping lots of requests before even trying to handle them,
 * I suppose you could call us "overloaded"
 */
/**
 ** unused, see handleReq() below
 *    private final static int MAX_PROACTIVE_DROPS = 240;
 *
 *    private int countProactiveDrops() {
 *        int dropped = 0;
 *        dropped += countEvents("tunnel.dropLoadProactive", 60*1000);
 *        dropped += countEvents("tunnel.dropLoad", 60*1000);
 *        dropped += countEvents("tunnel.dropLoadBacklog", 60*1000);
 *        dropped += countEvents("tunnel.dropLoadDelay", 60*1000);
 *        return dropped;
 *    }
 *
 *    private int countEvents(String stat, long period) {
 *        RateStat rs = _context.statManager().getRate(stat);
 *        if (rs != null) {
 *            Rate r = rs.getRate(period);
 *            if (r != null)
 *                return (int)r.getCurrentEventCount();
 *        }
 *        return 0;
 *    }
 ***
 */
/**
 *  Actually process the request and send the reply.
 *
 *  Todo: Replies are not subject to RED for bandwidth reasons,
 *  and the bandwidth is not credited to any tunnel.
 *  If we did credit the reply to the tunnel, it would
 *  prevent the classification of the tunnel as 'inactive' on tunnels.jsp.
 */
private void handleReq(RouterInfo nextPeerInfo, BuildMessageState state, BuildRequestRecord req, Hash nextPeer) {
    long ourId = req.readReceiveTunnelId();
    long nextId = req.readNextTunnelId();
    boolean isInGW = req.readIsInboundGateway();
    boolean isOutEnd = req.readIsOutboundEndpoint();
    Hash from = state.fromHash;
    if (from == null && state.from != null)
        from = state.from.calculateHash();
    if (isInGW && isOutEnd) {
        _context.statManager().addRateData("tunnel.rejectHostile", 1);
        _log.error("Dropping build request, IBGW+OBEP: " + req);
        if (from != null)
            _context.commSystem().mayDisconnect(from);
        return;
    }
    if (ourId <= 0 || ourId > TunnelId.MAX_ID_VALUE || nextId <= 0 || nextId > TunnelId.MAX_ID_VALUE) {
        _context.statManager().addRateData("tunnel.rejectHostile", 1);
        if (_log.shouldWarn())
            _log.warn("Dropping build request, bad tunnel ID: " + req);
        if (from != null)
            _context.commSystem().mayDisconnect(from);
        return;
    }
    // Loop checks
    if ((!isOutEnd) && _context.routerHash().equals(nextPeer)) {
        _context.statManager().addRateData("tunnel.rejectHostile", 1);
        // old i2pd
        if (_log.shouldWarn())
            _log.warn("Dropping build request, we are the next hop: " + req);
        if (from != null)
            _context.commSystem().mayDisconnect(from);
        return;
    }
    if (!isInGW) {
        // but if not, something is seriously wrong here.
        if (from == null || _context.routerHash().equals(from)) {
            _context.statManager().addRateData("tunnel.rejectHostile", 1);
            if (_log.shouldWarn())
                _log.warn("Dropping build request, we are the previous hop: " + req);
            return;
        }
    }
    if ((!isOutEnd) && (!isInGW)) {
        // A-B-C-A is not preventable
        if (nextPeer.equals(from)) {
            // i2pd does this
            _context.statManager().addRateData("tunnel.rejectHostile", 1);
            if (_log.shouldLog(Log.WARN))
                _log.warn("Dropping build request with the same previous and next hop: " + req);
            _context.commSystem().mayDisconnect(from);
            return;
        }
    }
    // time is in hours, rounded down.
    // tunnel-alt-creation.html specifies that this is enforced +/- 1 hour but it was not.
    // As of 0.9.16, allow + 5 minutes to - 65 minutes.
    long time = req.readRequestTime();
    long now = (_context.clock().now() / (60l * 60l * 1000l)) * (60 * 60 * 1000);
    long timeDiff = now - time;
    if (timeDiff > MAX_REQUEST_AGE) {
        _context.statManager().addRateData("tunnel.rejectTooOld", 1);
        if (_log.shouldLog(Log.WARN))
            _log.warn("Dropping build request too old... replay attack? " + DataHelper.formatDuration(timeDiff) + ": " + req);
        if (from != null)
            _context.commSystem().mayDisconnect(from);
        return;
    }
    if (timeDiff < 0 - MAX_REQUEST_FUTURE) {
        _context.statManager().addRateData("tunnel.rejectFuture", 1);
        if (_log.shouldLog(Log.WARN))
            _log.warn("Dropping build request too far in future " + DataHelper.formatDuration(0 - timeDiff) + ": " + req);
        if (from != null)
            _context.commSystem().mayDisconnect(from);
        return;
    }
    int response;
    if (_context.router().isHidden()) {
        _context.throttle().setTunnelStatus(_x("Rejecting tunnels: Hidden mode"));
        response = TunnelHistory.TUNNEL_REJECT_BANDWIDTH;
    } else {
        response = _context.throttle().acceptTunnelRequest();
    }
    // This only checked OUR tunnels, so the log message was wrong.
    // Now checked by TunnelDispatcher.joinXXX()
    // and returned as success value, checked below.
    // if (_context.tunnelManager().getTunnelInfo(new TunnelId(ourId)) != null) {
    // if (_log.shouldLog(Log.ERROR))
    // _log.error("Already participating in a tunnel with the given Id (" + ourId + "), so gotta reject");
    // if (response == 0)
    // response = TunnelHistory.TUNNEL_REJECT_PROBABALISTIC_REJECT;
    // }
    // if ( (response == 0) && (_context.random().nextInt(50) <= 1) )
    // response = TunnelHistory.TUNNEL_REJECT_PROBABALISTIC_REJECT;
    long recvDelay = _context.clock().now() - state.recvTime;
    if (response == 0) {
        // unused
        // int proactiveDrops = countProactiveDrops();
        float pDrop = ((float) recvDelay) / (float) (BuildRequestor.REQUEST_TIMEOUT * 3);
        pDrop = (float) Math.pow(pDrop, 16);
        if (_context.random().nextFloat() < pDrop) {
            // || (proactiveDrops > MAX_PROACTIVE_DROPS) ) ) {
            _context.statManager().addRateData("tunnel.rejectOverloaded", recvDelay);
            _context.throttle().setTunnelStatus(_x("Rejecting tunnels: Request overload"));
            // if (true || (proactiveDrops < MAX_PROACTIVE_DROPS*2))
            response = TunnelHistory.TUNNEL_REJECT_TRANSIENT_OVERLOAD;
        // else
        // response = TunnelHistory.TUNNEL_REJECT_BANDWIDTH;
        } else {
            _context.statManager().addRateData("tunnel.acceptLoad", recvDelay);
        }
    }
    /*
         * Being a IBGW or OBEP generally leads to more connections, so if we are
         * approaching our connection limit (i.e. !haveCapacity()),
         * reject this request.
         *
         * Don't do this for class N or O, under the assumption that they are already talking
         * to most of the routers, so there's no reason to reject. This may drive them
         * to their conn. limits, but it's hopefully a temporary solution to the
         * tunnel build congestion. As the net grows this will have to be revisited.
         */
    RouterInfo ri = _context.router().getRouterInfo();
    if (response == 0) {
        if (ri == null) {
            // ?? We should always have a RI
            response = TunnelHistory.TUNNEL_REJECT_BANDWIDTH;
        } else {
            char bw = ri.getBandwidthTier().charAt(0);
            if (bw != 'O' && bw != 'N' && bw != 'P' && bw != 'X' && ((isInGW && !_context.commSystem().haveInboundCapacity(87)) || (isOutEnd && !_context.commSystem().haveOutboundCapacity(87)))) {
                _context.statManager().addRateData("tunnel.rejectConnLimits", 1);
                _context.throttle().setTunnelStatus(_x("Rejecting tunnels: Connection limit"));
                response = TunnelHistory.TUNNEL_REJECT_BANDWIDTH;
            }
        }
    }
    // We may need another counter above for requests.
    if (response == 0 && !isInGW) {
        if (from != null && _throttler.shouldThrottle(from)) {
            if (_log.shouldLog(Log.WARN))
                _log.warn("Rejecting tunnel (hop throttle), previous hop: " + from + ": " + req);
            // no setTunnelStatus() indication
            _context.statManager().addRateData("tunnel.rejectHopThrottle", 1);
            response = TunnelHistory.TUNNEL_REJECT_BANDWIDTH;
        }
    }
    if (response == 0 && (!isOutEnd) && _throttler.shouldThrottle(nextPeer)) {
        if (_log.shouldLog(Log.WARN))
            _log.warn("Rejecting tunnel (hop throttle), next hop: " + req);
        _context.statManager().addRateData("tunnel.rejectHopThrottle", 1);
        // no setTunnelStatus() indication
        response = TunnelHistory.TUNNEL_REJECT_BANDWIDTH;
    }
    HopConfig cfg = null;
    if (response == 0) {
        cfg = new HopConfig();
        cfg.setCreation(_context.clock().now());
        cfg.setExpiration(_context.clock().now() + 10 * 60 * 1000);
        cfg.setIVKey(req.readIVKey());
        cfg.setLayerKey(req.readLayerKey());
        if (isInGW) {
        // default
        // cfg.setReceiveFrom(null);
        } else {
            if (from != null) {
                cfg.setReceiveFrom(from);
            } else {
                // b0rk
                return;
            }
        }
        cfg.setReceiveTunnelId(DataHelper.toLong(4, ourId));
        if (isOutEnd) {
        // default
        // cfg.setSendTo(null);
        // cfg.setSendTunnelId(null);
        } else {
            cfg.setSendTo(nextPeer);
            cfg.setSendTunnelId(DataHelper.toLong(4, nextId));
        }
        // now "actually" join
        boolean success;
        if (isOutEnd)
            success = _context.tunnelDispatcher().joinOutboundEndpoint(cfg);
        else if (isInGW)
            success = _context.tunnelDispatcher().joinInboundGateway(cfg);
        else
            success = _context.tunnelDispatcher().joinParticipant(cfg);
        if (success) {
            if (_log.shouldLog(Log.DEBUG))
                _log.debug("Joining: " + req);
        } else {
            // Dup Tunnel ID. This can definitely happen (birthday paradox).
            // Probability in 11 minutes (per hop type):
            // 0.1% for 2900 tunnels; 1% for 9300 tunnels
            response = TunnelHistory.TUNNEL_REJECT_BANDWIDTH;
            _context.statManager().addRateData("tunnel.rejectDupID", 1);
            if (_log.shouldLog(Log.WARN))
                _log.warn("DUP ID failure: " + req);
        }
    }
    if (response != 0) {
        _context.statManager().addRateData("tunnel.reject." + response, 1);
        _context.messageHistory().tunnelRejected(from, new TunnelId(ourId), nextPeer, // (isOutEnd ? "outbound endpoint" : isInGW ? "inbound gw" : "participant"));
        Integer.toString(response));
        if (from != null)
            _context.commSystem().mayDisconnect(from);
        // 81% = between 75% control measures in Transports and 87% rejection above
        if ((!_context.routerHash().equals(nextPeer)) && (!_context.commSystem().haveOutboundCapacity(81)) && (!_context.commSystem().isEstablished(nextPeer))) {
            _context.statManager().addRateData("tunnel.dropConnLimits", 1);
            if (_log.shouldLog(Log.WARN))
                _log.warn("Not sending rejection due to conn limits: " + req);
            return;
        }
    } else if (isInGW && from != null) {
        // we're the start of the tunnel, no use staying connected
        _context.commSystem().mayDisconnect(from);
    }
    if (_log.shouldLog(Log.DEBUG))
        _log.debug("Responding to " + state.msg.getUniqueId() + " after " + recvDelay + " with " + response + " from " + (from != null ? from : "tunnel") + ": " + req);
    EncryptedBuildRecord reply = BuildResponseRecord.create(_context, response, req.readReplyKey(), req.readReplyIV(), state.msg.getUniqueId());
    int records = state.msg.getRecordCount();
    int ourSlot = -1;
    for (int j = 0; j < records; j++) {
        if (state.msg.getRecord(j) == null) {
            ourSlot = j;
            state.msg.setRecord(j, reply);
            // + ": " + Base64.encode(reply));
            break;
        }
    }
    if (_log.shouldLog(Log.DEBUG))
        _log.debug("Read slot " + ourSlot + " containing: " + req + " accepted? " + response + " recvDelay " + recvDelay + " replyMessage " + req.readReplyMessageId());
    // now actually send the response
    long expires = _context.clock().now() + NEXT_HOP_SEND_TIMEOUT;
    if (!isOutEnd) {
        state.msg.setUniqueId(req.readReplyMessageId());
        state.msg.setMessageExpiration(expires);
        OutNetMessage msg = new OutNetMessage(_context, state.msg, expires, PRIORITY, nextPeerInfo);
        if (response == 0)
            msg.setOnFailedSendJob(new TunnelBuildNextHopFailJob(_context, cfg));
        _context.outNetMessagePool().add(msg);
    } else {
        // We are the OBEP.
        // send it to the reply tunnel on the reply peer within a new TunnelBuildReplyMessage
        // (enough layers jrandom?)
        TunnelBuildReplyMessage replyMsg;
        if (records == TunnelBuildMessage.MAX_RECORD_COUNT)
            replyMsg = new TunnelBuildReplyMessage(_context);
        else
            replyMsg = new VariableTunnelBuildReplyMessage(_context, records);
        for (int i = 0; i < records; i++) replyMsg.setRecord(i, state.msg.getRecord(i));
        replyMsg.setUniqueId(req.readReplyMessageId());
        replyMsg.setMessageExpiration(expires);
        TunnelGatewayMessage m = new TunnelGatewayMessage(_context);
        m.setMessage(replyMsg);
        m.setMessageExpiration(expires);
        m.setTunnelId(new TunnelId(nextId));
        if (_context.routerHash().equals(nextPeer)) {
            // ok, we are the gateway, so inject it
            if (_log.shouldLog(Log.DEBUG))
                _log.debug("We are the reply gateway for " + nextId + " when replying to replyMessage " + req);
            _context.tunnelDispatcher().dispatch(m);
        } else {
            // ok, the gateway is some other peer, shove 'er across
            OutNetMessage outMsg = new OutNetMessage(_context, m, expires, PRIORITY, nextPeerInfo);
            if (response == 0)
                outMsg.setOnFailedSendJob(new TunnelBuildNextHopFailJob(_context, cfg));
            _context.outNetMessagePool().add(outMsg);
        }
    }
}

Example 2 with EncryptedBuildRecord

use of net.i2p.data.i2np.EncryptedBuildRecord in project i2p.i2p by i2p.

the class BuildMessageGenerator method createRecord.

/**
 * return null if it is unable to find a router's public key (etc)
 */
/**
 **
 *    public TunnelBuildMessage createInbound(RouterContext ctx, TunnelCreatorConfig cfg) {
 *        return create(ctx, cfg, null, -1);
 *    }
 ***
 */
/**
 * return null if it is unable to find a router's public key (etc)
 */
/**
 **
 *    public TunnelBuildMessage createOutbound(RouterContext ctx, TunnelCreatorConfig cfg, Hash replyRouter, long replyTunnel) {
 *        return create(ctx, cfg, replyRouter, replyTunnel);
 *    }
 ***
 */
/**
 **
 *    private TunnelBuildMessage create(RouterContext ctx, TunnelCreatorConfig cfg, Hash replyRouter, long replyTunnel) {
 *        TunnelBuildMessage msg = new TunnelBuildMessage(ctx);
 *        List order = new ArrayList(ORDER.length);
 *        for (int i = 0; i < ORDER.length; i++) order.add(ORDER[i]);
 *        Collections.shuffle(order, ctx.random());
 *        for (int i = 0; i < ORDER.length; i++) {
 *            int hop = ((Integer)order.get(i)).intValue();
 *            Hash peer = cfg.getPeer(hop);
 *            RouterInfo ri = ctx.netDb().lookupRouterInfoLocally(peer);
 *            if (ri == null)
 *                return null;
 *            createRecord(i, hop, msg, cfg, replyRouter, replyTunnel, ctx, ri.getIdentity().getPublicKey());
 *        }
 *        layeredEncrypt(ctx, msg, cfg, order);
 *        return msg;
 *    }
 ***
 */
/**
 * Place the asymmetrically encrypted record in the specified record slot,
 * containing the hop's configuration (as well as the reply info, if it is an outbound endpoint)
 *
 * @param msg out parameter
 * @param peerKey Encrypt using this key.
 *                If null, replyRouter and replyTunnel are ignored,
 *                and the entire record is filled with random data
 * @throws IllegalArgumentException if hop bigger than config
 */
public static void createRecord(int recordNum, int hop, TunnelBuildMessage msg, TunnelCreatorConfig cfg, Hash replyRouter, long replyTunnel, I2PAppContext ctx, PublicKey peerKey) {
    // Log log = ctx.logManager().getLog(BuildMessageGenerator.class);
    EncryptedBuildRecord erec;
    if (peerKey != null) {
        BuildRequestRecord req = null;
        if (// outbound endpoint
        (!cfg.isInbound()) && (hop + 1 == cfg.getLength()))
            req = createUnencryptedRecord(ctx, cfg, hop, replyRouter, replyTunnel);
        else
            req = createUnencryptedRecord(ctx, cfg, hop, null, -1);
        if (req == null)
            throw new IllegalArgumentException("hop bigger than config");
        Hash peer = cfg.getPeer(hop);
        // if (log.shouldLog(Log.DEBUG))
        // log.debug("Record " + recordNum + "/" + hop + "/" + peer.toBase64()
        // + ": unencrypted = " + Base64.encode(req.getData().getData()));
        erec = req.encryptRecord(ctx, peerKey, peer);
    // if (log.shouldLog(Log.DEBUG))
    // log.debug("Record " + recordNum + "/" + hop + ": encrypted   = " + Base64.encode(encrypted));
    } else {
        // if (log.shouldLog(Log.DEBUG))
        // log.debug("Record " + recordNum + "/" + hop + "/ is blank/random");
        byte[] encrypted = new byte[TunnelBuildMessage.RECORD_SIZE];
        ctx.random().nextBytes(encrypted);
        erec = new EncryptedBuildRecord(encrypted);
    }
    msg.setRecord(recordNum, erec);
}

Example 3 with EncryptedBuildRecord

use of net.i2p.data.i2np.EncryptedBuildRecord in project i2p.i2p by i2p.

the class BuildMessageGenerator method layeredEncrypt.

/**
 * Encrypt the records so their hop ident is visible at the appropriate times.
 *
 * Note that this layer-encrypts the build records for the message in-place.
 * Only call this once for a given message.
 *
 * @param order list of hop #s as Integers.  For instance, if (order.get(1) is 4), it is peer cfg.getPeer(4)
 */
public static void layeredEncrypt(I2PAppContext ctx, TunnelBuildMessage msg, TunnelCreatorConfig cfg, List<Integer> order) {
    // encrypt the records so that the right elements will be visible at the right time
    for (int i = 0; i < msg.getRecordCount(); i++) {
        EncryptedBuildRecord rec = msg.getRecord(i);
        Integer hopNum = order.get(i);
        int hop = hopNum.intValue();
        if ((isBlank(cfg, hop)) || (!cfg.isInbound() && hop == 1)) {
            // log.debug(msg.getUniqueId() + ": not pre-decrypting record " + i + "/" + hop + " for " + cfg);
            continue;
        }
        // if (log.shouldLog(Log.DEBUG))
        // log.debug(msg.getUniqueId() + ": pre-decrypting record " + i + "/" + hop + " for " + cfg);
        // ok, now decrypt the record with all of the reply keys from cfg.getConfig(0) through hop-1
        int stop = (cfg.isInbound() ? 0 : 1);
        for (int j = hop - 1; j >= stop; j--) {
            HopConfig hopConfig = cfg.getConfig(j);
            SessionKey key = hopConfig.getReplyKey();
            byte[] iv = hopConfig.getReplyIV();
            // if (log.shouldLog(Log.DEBUG))
            // log.debug(msg.getUniqueId() + ": pre-decrypting record " + i + "/" + hop + " for " + cfg
            // + " with " + key.toBase64() + "/" + Base64.encode(iv));
            // corrupts the SDS
            ctx.aes().decrypt(rec.getData(), 0, rec.getData(), 0, key, iv, TunnelBuildMessage.RECORD_SIZE);
        }
    }
// if (log.shouldLog(Log.DEBUG))
// log.debug(msg.getUniqueId() + ": done pre-decrypting all records for " + cfg);
}

Example 4 with EncryptedBuildRecord

use of net.i2p.data.i2np.EncryptedBuildRecord in project i2p.i2p by i2p.

the class BuildMessageProcessor method decrypt.

/**
 * Decrypt the record targetting us, encrypting all of the other records with the included
 * reply key and IV.  The original, encrypted record targetting us is removed from the request
 * message (so that the reply can be placed in that position after going through the decrypted
 * request record).
 *
 * Note that this layer-decrypts the build records in-place.
 * Do not call this more than once for a given message.
 *
 * @return the current hop's decrypted record or null on failure
 */
public BuildRequestRecord decrypt(TunnelBuildMessage msg, Hash ourHash, PrivateKey privKey) {
    BuildRequestRecord rv = null;
    int ourHop = -1;
    long beforeActualDecrypt = 0;
    long afterActualDecrypt = 0;
    byte[] ourHashData = ourHash.getData();
    long beforeLoop = System.currentTimeMillis();
    for (int i = 0; i < msg.getRecordCount(); i++) {
        EncryptedBuildRecord rec = msg.getRecord(i);
        int len = BuildRequestRecord.PEER_SIZE;
        boolean eq = DataHelper.eq(ourHashData, 0, rec.getData(), 0, len);
        if (eq) {
            beforeActualDecrypt = System.currentTimeMillis();
            try {
                rv = new BuildRequestRecord(ctx, privKey, rec);
                afterActualDecrypt = System.currentTimeMillis();
                // i2pd bug
                boolean isBad = SessionKey.INVALID_KEY.equals(rv.readReplyKey());
                if (isBad) {
                    if (log.shouldLog(Log.WARN))
                        log.warn(msg.getUniqueId() + ": Bad reply key: " + rv);
                    ctx.statManager().addRateData("tunnel.buildRequestBadReplyKey", 1);
                    return null;
                }
                // The spec says to feed the 32-byte AES-256 reply key into the Bloom filter.
                // But we were using the first 32 bytes of the encrypted reply.
                // Fixed in 0.9.24
                boolean isDup = _filter.add(rv.getData(), BuildRequestRecord.OFF_REPLY_KEY, 32);
                if (isDup) {
                    if (log.shouldLog(Log.WARN))
                        log.warn(msg.getUniqueId() + ": Dup record: " + rv);
                    ctx.statManager().addRateData("tunnel.buildRequestDup", 1);
                    return null;
                }
                if (log.shouldLog(Log.DEBUG))
                    log.debug(msg.getUniqueId() + ": Matching record: " + rv);
                ourHop = i;
                // TODO should we keep looking for a second match and fail if found?
                break;
            } catch (DataFormatException dfe) {
                if (log.shouldLog(Log.WARN))
                    log.warn(msg.getUniqueId() + ": Matching record decrypt failure", dfe);
                // out there with the same first 16 bytes, go around again
                continue;
            }
        }
    }
    if (rv == null) {
        // none of the records matched, b0rk
        if (log.shouldLog(Log.WARN))
            log.warn(msg.getUniqueId() + ": No matching record");
        return null;
    }
    long beforeEncrypt = System.currentTimeMillis();
    SessionKey replyKey = rv.readReplyKey();
    byte[] iv = rv.readReplyIV();
    for (int i = 0; i < msg.getRecordCount(); i++) {
        if (i != ourHop) {
            EncryptedBuildRecord data = msg.getRecord(i);
            // if (log.shouldLog(Log.DEBUG))
            // log.debug("Encrypting record " + i + "/? with replyKey " + replyKey.toBase64() + "/" + Base64.encode(iv));
            // encrypt in-place, corrupts SDS
            byte[] bytes = data.getData();
            ctx.aes().encrypt(bytes, 0, bytes, 0, replyKey, iv, 0, EncryptedBuildRecord.LENGTH);
        }
    }
    long afterEncrypt = System.currentTimeMillis();
    msg.setRecord(ourHop, null);
    if (afterEncrypt - beforeLoop > 1000) {
        if (log.shouldLog(Log.WARN))
            log.warn("Slow decryption, total=" + (afterEncrypt - beforeLoop) + " looping=" + (beforeEncrypt - beforeLoop) + " decrypt=" + (afterActualDecrypt - beforeActualDecrypt) + " encrypt=" + (afterEncrypt - beforeEncrypt));
    }
    return rv;
}

Example 5 with EncryptedBuildRecord

use of net.i2p.data.i2np.EncryptedBuildRecord in project i2p.i2p by i2p.

the class BuildReplyHandler method decryptRecord.

/**
 * Decrypt the record (removing the layers of reply encyption) and read out the status
 *
 * Note that this layer-decrypts the build records in-place.
 * Do not call this more than once for a given message.
 *
 * @return the status 0-255, or -1 on decrypt failure
 */
private int decryptRecord(TunnelBuildReplyMessage reply, TunnelCreatorConfig cfg, int recordNum, int hop) {
    if (BuildMessageGenerator.isBlank(cfg, hop)) {
        if (log.shouldLog(Log.DEBUG))
            log.debug(reply.getUniqueId() + ": Record " + recordNum + "/" + hop + " is fake, so consider it valid...");
        return 0;
    }
    EncryptedBuildRecord rec = reply.getRecord(recordNum);
    byte[] data = rec.getData();
    int start = cfg.getLength() - 1;
    if (cfg.isInbound())
        // the last hop in an inbound tunnel response doesn't actually encrypt
        start--;
    // do we need to adjust this for the endpoint?
    for (int j = start; j >= hop; j--) {
        HopConfig hopConfig = cfg.getConfig(j);
        SessionKey replyKey = hopConfig.getReplyKey();
        byte[] replyIV = hopConfig.getReplyIV();
        if (log.shouldLog(Log.DEBUG)) {
            log.debug(reply.getUniqueId() + ": Decrypting record " + recordNum + "/" + hop + "/" + j + " with replyKey " + replyKey.toBase64() + "/" + Base64.encode(replyIV) + ": " + cfg);
            log.debug(reply.getUniqueId() + ": before decrypt: " + Base64.encode(data));
            log.debug(reply.getUniqueId() + ": Full reply rec: sz=" + data.length + " data=" + Base64.encode(data, 0, TunnelBuildReplyMessage.RECORD_SIZE));
        }
        ctx.aes().decrypt(data, 0, data, 0, replyKey, replyIV, 0, TunnelBuildReplyMessage.RECORD_SIZE);
        if (log.shouldLog(Log.DEBUG))
            log.debug(reply.getUniqueId() + ": after decrypt: " + Base64.encode(data));
    }
    // ok, all of the layered encryption is stripped, so lets verify it
    // (formatted per BuildResponseRecord.create)
    // don't cache the result
    // Hash h = ctx.sha().calculateHash(data, off + Hash.HASH_LENGTH, TunnelBuildReplyMessage.RECORD_SIZE-Hash.HASH_LENGTH);
    byte[] h = SimpleByteCache.acquire(Hash.HASH_LENGTH);
    ctx.sha().calculateHash(data, Hash.HASH_LENGTH, TunnelBuildReplyMessage.RECORD_SIZE - Hash.HASH_LENGTH, h, 0);
    boolean ok = DataHelper.eq(h, 0, data, 0, Hash.HASH_LENGTH);
    if (!ok) {
        if (log.shouldLog(Log.DEBUG))
            log.debug(reply.getUniqueId() + ": Failed verification on " + recordNum + "/" + hop + ": " + Base64.encode(h) + " calculated, " + Base64.encode(data, 0, Hash.HASH_LENGTH) + " expected\n" + "Record: " + Base64.encode(data, Hash.HASH_LENGTH, TunnelBuildReplyMessage.RECORD_SIZE - Hash.HASH_LENGTH));
        SimpleByteCache.release(h);
        return -1;
    } else {
        SimpleByteCache.release(h);
        int rv = data[TunnelBuildReplyMessage.RECORD_SIZE - 1] & 0xff;
        if (log.shouldLog(Log.DEBUG))
            log.debug(reply.getUniqueId() + ": Verified: " + rv + " for record " + recordNum + "/" + hop);
        return rv;
    }
}