Merge pull request 'Transports: Remove ElG DH builder' (#508) from zzz/i2p.i2p:elgdh into master

Reviewed-on: #508
Reviewed-by: idk <idki2p@mail.i2p>

router/java/src/net/i2p/router/CommSystemFacade.java

@@ -21,7 +21,6 @@ import net.i2p.data.Hash;
 import net.i2p.data.router.RouterAddress;
 import net.i2p.data.router.RouterInfo;
 import net.i2p.router.transport.Transport;
-import net.i2p.router.transport.crypto.DHSessionKeyBuilder;
 import net.i2p.router.transport.crypto.X25519KeyFactory;
 import net.i2p.util.Translate;
 
@@ -207,12 +206,6 @@ public abstract class CommSystemFacade implements Service {
      */
     public void unregisterTransport(Transport t) {}
 
-    /**
-     *  Hook for pluggable transport creation.
-     *  @since 0.9.16
-     */
-    public DHSessionKeyBuilder.Factory getDHFactory() { return null; }
-
     /**
      *  Factory for making X25519 key pairs.
      *  @since 0.9.46

router/java/src/net/i2p/router/transport/CommSystemFacadeImpl.java

@@ -27,7 +27,6 @@ import net.i2p.data.router.RouterInfo;
 import net.i2p.router.CommSystemFacade;
 import net.i2p.router.OutNetMessage;
 import net.i2p.router.RouterContext;
-import net.i2p.router.transport.crypto.DHSessionKeyBuilder;
 import net.i2p.router.transport.crypto.X25519KeyFactory;
 import net.i2p.router.transport.udp.UDPTransport;
 import net.i2p.router.util.EventLog;
@@ -452,16 +451,6 @@ public class CommSystemFacadeImpl extends CommSystemFacade {
         _manager.stopAndUnregister(t);
     }
 
-    /**
-     *  Hook for pluggable transport creation.
-     *
-     *  @since 0.9.16
-     */
-    @Override
-    public DHSessionKeyBuilder.Factory getDHFactory() {
-        return _manager.getDHFactory();
-    }
-
     /**
      *  Factory for making X25519 key pairs.
      *  @since 0.9.46

router/java/src/net/i2p/router/transport/TransportManager.java

@@ -40,7 +40,6 @@ import net.i2p.router.CommSystemFacade.Status;
 import net.i2p.router.OutNetMessage;
 import net.i2p.router.RouterContext;
 import static net.i2p.router.transport.Transport.AddressSource.*;
-import net.i2p.router.transport.crypto.DHSessionKeyBuilder;
 import net.i2p.router.transport.crypto.X25519KeyFactory;
 import net.i2p.router.transport.ntcp.NTCPTransport;
 import net.i2p.router.transport.udp.UDPTransport;
@@ -75,7 +74,6 @@ public class TransportManager implements TransportEventListener {
     private final RouterContext _context;
     private final UPnPManager _upnpManager;
     private final SimpleTimer2.TimedEvent _upnpRefresher;
-    private final DHSessionKeyBuilder.PrecalcRunner _dhThread;
     private final X25519KeyFactory _xdhThread;
     private final boolean _enableUDP;
     private final boolean _enableNTCP1;
@@ -123,7 +121,6 @@ public class TransportManager implements TransportEventListener {
         _enableUDP = _context.getBooleanPropertyDefaultTrue(PROP_ENABLE_UDP);
         _enableNTCP1 = false;
         boolean enableNTCP2 = isNTCPEnabled(context);
-        _dhThread = (_enableUDP || enableNTCP2) ? new DHSessionKeyBuilder.PrecalcRunner(context) : null;
         // always created, even if NTCP2 is not enabled, because ratchet needs it
         _xdhThread = new X25519KeyFactory(context);
         _msgIDBloomXor = _context.random().nextLong(I2NPMessage.MAX_ID_VALUE);
@@ -221,16 +218,6 @@ public class TransportManager implements TransportEventListener {
         _context.router().rebuildRouterInfo();
     }
 
-    /**
-     *  Hook for pluggable transport creation.
-     *
-     *  @return null if both NTCP1 and SSU are disabled
-     *  @since 0.9.16
-     */
-    DHSessionKeyBuilder.Factory getDHFactory() {
-        return _dhThread;
-    }
-
     /**
      *  Factory for making X25519 key pairs.
      *  @since 0.9.46
@@ -263,7 +250,7 @@ public class TransportManager implements TransportEventListener {
             initializeAddress(udp);
         }
         if (isNTCPEnabled(_context)) {
-            Transport ntcp = new NTCPTransport(_context, null, _xdhThread);
+            Transport ntcp = new NTCPTransport(_context, _xdhThread);
             addTransport(ntcp);
             initializeAddress(ntcp);
             if (udp != null) {
@@ -435,8 +422,6 @@ public class TransportManager implements TransportEventListener {
     }
 
     synchronized void startListening() {
-        if (_dhThread != null && _dhThread.getState() == Thread.State.NEW)
-            _dhThread.start();
         if (_xdhThread != null && _xdhThread.getState() == Thread.State.NEW)
             _xdhThread.start();
         // For now, only start UPnP if we have no publicly-routable addresses
@@ -504,8 +489,6 @@ public class TransportManager implements TransportEventListener {
      */
     synchronized void shutdown() {
         stopListening();
-        if (_dhThread != null)
-            _dhThread.shutdown();
         if (_xdhThread != null)
             _xdhThread.shutdown();
         Addresses.clearCaches();

router/java/src/net/i2p/router/transport/crypto/DHSessionKeyBuilder.java

@@ -1,620 +0,0 @@
-package net.i2p.router.transport.crypto;
-
-/*
- * free (adj.): unencumbered; not under the control of others
- * Written by jrandom in 2003 and released into the public domain 
- * with no warranty of any kind, either expressed or implied.  
- * It probably won't  make your computer catch on fire, or eat 
- * your children, but it might.  Use at your own risk.
- *
- */
-
-//import java.io.InputStream;
-//import java.io.OutputStream;
-import java.math.BigInteger;
-import java.security.InvalidKeyException;
-import java.util.concurrent.LinkedBlockingQueue;
-
-import net.i2p.I2PAppContext;
-import net.i2p.I2PException;
-import net.i2p.crypto.CryptoConstants;
-import net.i2p.crypto.SHA256Generator;
-import net.i2p.crypto.SigUtil;
-import net.i2p.data.ByteArray;
-//import net.i2p.data.DataHelper;
-import net.i2p.data.SessionKey;
-import net.i2p.util.I2PThread;
-import net.i2p.util.Log;
-import net.i2p.util.NativeBigInteger;
-import net.i2p.util.RandomSource;
-import net.i2p.util.SystemVersion;
-
-/**
- * Generate a new session key through a diffie hellman exchange.  This uses the
- * constants defined in CryptoConstants, which causes the exchange to create a 
- * 256 bit session key.
- *
- * This class precalcs a set of values on its own thread.
- * Whenever the pool has
- * less than the minimum, it fills it up again to the max.  There is a delay after 
- * each precalculation so that the CPU isn't hosed during startup.  
- * These three parameters are controlled by java environmental variables and 
- * can be adjusted via:
- *  -Dcrypto.dh.precalc.min=40 -Dcrypto.dh.precalc.max=100 -Dcrypto.dh.precalc.delay=60000
- *
- * (delay is milliseconds)
- *
- * To disable precalculation, set min to 0
- *
- * @since 0.9 moved from net.i2p.crypto
- *
- * @author jrandom
- */
-public class DHSessionKeyBuilder {
-
-    // the data of importance
-    private final BigInteger _myPrivateValue;
-    private final BigInteger _myPublicValue;
-    private BigInteger _peerValue;
-    private SessionKey _sessionKey;
-    private final ByteArray _extraExchangedBytes; // bytes after the session key from the DH exchange
-
-    private final static String PROP_DH_PRECALC_MIN = "crypto.dh.precalc.min";
-    private final static String PROP_DH_PRECALC_MAX = "crypto.dh.precalc.max";
-    private final static String PROP_DH_PRECALC_DELAY = "crypto.dh.precalc.delay";
-    private final static int DEFAULT_DH_PRECALC_MIN = 20;
-    private final static int DEFAULT_DH_PRECALC_MAX = 60;
-    private final static int DEFAULT_DH_PRECALC_DELAY = 25;
-
-    /**
-     * Create a new public/private value pair for the DH exchange.
-     * Only for internal use and unit tests.
-     * Others should get instances from PrecalcRunner.getBuilder()
-     */
-    DHSessionKeyBuilder() {
-        this(I2PAppContext.getGlobalContext());
-    }
-
-    /**
-     * Create a new public/private value pair for the DH exchange.
-     * Only for internal use and unit tests.
-     * Others should get instances from PrecalcRunner.getBuilder()
-     */
-    DHSessionKeyBuilder(I2PAppContext ctx) {
-        _myPrivateValue = new NativeBigInteger(ctx.keyGenerator().getElGamalExponentSize(), ctx.random());
-        _myPublicValue = CryptoConstants.elgg.modPow(_myPrivateValue, CryptoConstants.elgp);
-        _extraExchangedBytes = new ByteArray();
-    }
-    
-    /**
-     * Conduct a DH exchange over the streams, returning the resulting data.
-     *
-     * unused
-     * @return exchanged data
-     * @throws IOException if there is an error (but does not close the streams
-     */
-/****
-    public static DHSessionKeyBuilder exchangeKeys(InputStream in, OutputStream out) throws IOException {
-        DHSessionKeyBuilder builder = new DHSessionKeyBuilder();
-        
-        // send: X
-        writeBigI(out, builder.getMyPublicValue());
-        
-        // read: Y
-        BigInteger Y = readBigI(in);
-        if (Y == null) return null;
-        try {
-            builder.setPeerPublicValue(Y);
-            return builder;
-        } catch (InvalidPublicParameterException ippe) {
-            if (_log.shouldLog(Log.ERROR))
-                _log.error("Key exchange failed (hostile peer?)", ippe);
-            return null;
-        }
-    }
-****/
-    
-    /**
-     * unused
-     */
-/****
-    private static BigInteger readBigI(InputStream in) throws IOException {
-        byte Y[] = new byte[256];
-        int read = DataHelper.read(in, Y);
-        if (read != 256) {
-            return null;
-        }
-        return new NativeBigInteger(1, Y);
-    }
-****/
-    
-    /**
-     * Write out the integer as a 256 byte value.  This left pads with 0s so 
-     * to keep in 2s complement, and if it is already 257 bytes (due to
-     * the sign bit) ignore that first byte.
-     *
-     * unused
-     */
-/****
-    private static void writeBigI(OutputStream out, BigInteger val) throws IOException {
-        byte x[] = val.toByteArray();
-        for (int i = x.length; i < 256; i++) 
-            out.write(0);
-        if (x.length == 257)
-            out.write(x, 1, 256);
-        else if (x.length == 256)
-            out.write(x);
-        else if (x.length > 257)
-            throw new IllegalArgumentException("Value is too large!  length="+x.length);
-        
-        out.flush();
-    }
-****/
-    
-    /**
-     * Retrieve the private value used by the local participant in the DH exchange
-     * unused
-     */
-/*
-    public BigInteger getMyPrivateValue() {
-        return _myPrivateValue;
-    }
-*/
-
-    /**
-     * Retrieve the public value used by the local participant in the DH exchange,
-     */
-    public BigInteger getMyPublicValue() {
-        return _myPublicValue;
-    }
-
-    /**
-     * Return a 256 byte representation of our public key, with leading 0s 
-     * if necessary.
-     *
-     */
-    public byte[] getMyPublicValueBytes() {
-        return toByteArray(getMyPublicValue());
-    }
-    
-    /**
-     *  @return exactly 256 bytes
-     *  @throws IllegalArgumentException if requires more than 256 bytes
-     */
-    private static final byte[] toByteArray(BigInteger bi) {
-        try {
-            return SigUtil.rectify(bi, 256);
-        } catch (InvalidKeyException ike) {
-            throw new IllegalArgumentException(ike);
-        }
-    }
-
-    /**
-     * Specify the value given by the peer for use in the session key negotiation
-     * @throws IllegalStateException if already set
-     */
-    public synchronized void setPeerPublicValue(BigInteger peerVal) throws InvalidPublicParameterException {
-        if (_peerValue != null) {
-            if (!_peerValue.equals(peerVal))
-                throw new IllegalStateException();
-            return;
-        }
-        validatePublic(peerVal);
-        _peerValue = peerVal;
-    }
-
-    /**
-     *  @param val 256 bytes
-     */
-    public void setPeerPublicValue(byte val[]) throws InvalidPublicParameterException {
-        if (val.length != 256)
-            throw new IllegalArgumentException("Peer public value must be exactly 256 bytes");
-        setPeerPublicValue(new NativeBigInteger(1, val));
-    }
-
-    public synchronized BigInteger getPeerPublicValue() {
-        return _peerValue;
-    }
-
-    /**
-     * Return a 256 byte representation of his public key, with leading 0s 
-     * if necessary.
-     *
-     */
-    public byte[] getPeerPublicValueBytes() {
-        return toByteArray(getPeerPublicValue());
-    }
-
-    /**
-     * Retrieve the session key, calculating it if necessary (and if possible).
-     *
-     * @return session key exchanged, or null if the exchange is not complete
-     */
-    public synchronized SessionKey getSessionKey() {
-        if (_sessionKey != null) return _sessionKey;
-        if (_peerValue != null) {
-            _sessionKey = calculateSessionKey(_myPrivateValue, _peerValue);
-        } else {
-            //System.err.println("Not ready yet.. privateValue and peerValue must be set ("
-            //                   + (_myPrivateValue != null ? "set" : "null") + ","
-            //                   + (_peerValue != null ? "set" : "null") + ")");
-        }
-        return _sessionKey;
-    }
-
-    /**
-     * Retrieve the extra bytes beyond the session key resulting from the DH exchange.
-     * If there aren't enough bytes (with all of them being consumed by the 32 byte key),
-     * the SHA256 of the key itself is used - but that won't ever happen.
-     *
-     * Used only by UDP. getData() will be non-null and have at least 32 bytes after call to getSessionKey()
-     *
-     * @return non-null (but rv.getData() may be null)
-     */
-    public ByteArray getExtraBytes() {
-        return _extraExchangedBytes;
-    }
-
-    /**
-     * Calculate a session key based on the private value and the public peer value.
-     *
-     * This is the first 32 bytes of the exchanged key (nominally 256 bytes),
-     * EXCEPT that the first byte will be zero if the most significant bit was a 1
-     * (Java BigInteger.toByteArray() format)
-     *
-     * Side effect - sets extraExchangedBytes to the next 32 bytes.
-     */
-    private final SessionKey calculateSessionKey(BigInteger myPrivateValue, BigInteger publicPeerValue) {
-        long start = System.currentTimeMillis();
-        SessionKey key = new SessionKey();
-        BigInteger exchangedKey = publicPeerValue.modPow(myPrivateValue, CryptoConstants.elgp);
-        // surprise! leading zero byte half the time!
-        // probably was a mistake, too late now...
-        byte buf[] = exchangedKey.toByteArray();
-        byte val[] = new byte[SessionKey.KEYSIZE_BYTES];
-        if (buf.length < 2 * SessionKey.KEYSIZE_BYTES) {
-            // UDP requires at least 32 bytes in _extraExchangedBytes for the mac key
-            // Won't ever happen, typ buf is 256 or 257 bytes
-            System.arraycopy(buf, 0, val, 0, Math.min(buf.length, SessionKey.KEYSIZE_BYTES));
-            byte remaining[] = new byte[SessionKey.KEYSIZE_BYTES];  // == Hash.HASH_LENGTH
-            // non-caching version
-            SHA256Generator.getInstance().calculateHash(buf, 0, buf.length, remaining, 0);
-            _extraExchangedBytes.setData(remaining);
-            //if (_log.shouldLog(Log.DEBUG))
-            //    _log.debug("Storing " + remaining.length + " bytes from the DH exchange by SHA256 the session key");
-        } else {
-            // Will always be here, typ buf is 256 or 257 bytes
-            System.arraycopy(buf, 0, val, 0, SessionKey.KEYSIZE_BYTES);
-            // feed the extra bytes into the PRNG
-            RandomSource.getInstance().harvester().feedEntropy("DH", buf, val.length, buf.length-val.length); 
-            byte remaining[] = new byte[buf.length - val.length];
-            System.arraycopy(buf, val.length, remaining, 0, remaining.length);
-            _extraExchangedBytes.setData(remaining);
-            //if (_log.shouldLog(Log.DEBUG))
-            //    _log.debug("Storing " + remaining.length + " bytes from the end of the DH exchange");
-        }
-        key.setData(val);
-        long end = System.currentTimeMillis();
-        long diff = end - start;
-        
-        I2PAppContext.getGlobalContext().statManager().addRateData("crypto.dhCalculateSessionTime", diff);
-        //if (diff > 1000) {
-        //    if (_log.shouldLog(Log.WARN)) _log.warn("Generating session key took too long (" + diff + " ms");
-        //} else {
-        //    if (_log.shouldLog(Log.DEBUG)) _log.debug("Generating session key " + diff + " ms");
-        //}
-        return key;
-    }
-    
-    /**
-     * rfc2631:
-     *  The following algorithm MAY be used to validate a received public key y.
-     *
-     *  1. Verify that y lies within the interval [2,p-1]. If it does not,
-     *     the key is invalid.
-     *  2. Compute y^q mod p. If the result == 1, the key is valid.
-     *     Otherwise the key is invalid.
-     */
-    private static final void validatePublic(BigInteger publicValue) throws InvalidPublicParameterException {
-        int cmp = publicValue.compareTo(NativeBigInteger.ONE);
-        if (cmp <= 0) 
-            throw new InvalidPublicParameterException("Public value is below two: " + publicValue.toString());
-        
-        cmp = publicValue.compareTo(CryptoConstants.elgp);
-        if (cmp >= 0) 
-            throw new InvalidPublicParameterException("Public value is above p-1: " + publicValue.toString());
-        
-        // todo: 
-        // whatever validation needs to be done to mirror the rfc's part 2 (we don't have a q, so can't do
-        // if (NativeBigInteger.ONE.compareTo(publicValue.modPow(q, CryptoConstants.elgp)) != 0)
-        //   throw new InvalidPublicParameterException("Invalid public value with y^q mod p != 1");
-        // 
-    }
-
-    /*
-    private static void testValidation() {
-        NativeBigInteger bi = new NativeBigInteger("-3416069082912684797963255430346582466254460710249795973742848334283491150671563023437888953432878859472362439146158925287289114133666004165938814597775594104058593692562989626922979416277152479694258099203456493995467386903611666213773085025718340335205240293383622352894862685806192183268523899615405287022135356656720938278415659792084974076416864813957028335830794117802560169423133816961503981757298122040391506600117301607823659479051969827845787626261515313227076880722069706394405554113103165334903531980102626092646197079218895216346725765704256096661045699444128316078549709132753443706200863682650825635513");
-        try { 
-            validatePublic(bi);
-            System.err.println("valid?!");
-        } catch (InvalidPublicParameterException ippe) {
-            System.err.println("Ok, invalid.  cool");
-        }
-        
-        byte val[] = bi.toByteArray();
-        System.out.println("Len: " + val.length + " first is ok? " + ( (val[0] & 0x80) == 1) 
-                           + "\n" + DataHelper.toString(val, 64));
-        NativeBigInteger bi2 = new NativeBigInteger(1, val);
-        try {
-            validatePublic(bi2);
-            System.out.println("valid");
-        } catch (InvalidPublicParameterException ippe) {
-            System.out.println("invalid");
-        }
-    }
-    */
-    
-/******
-    public static void main(String args[]) {
-        //if (true) { testValidation(); return; }
-        
-        RandomSource.getInstance().nextBoolean(); // warm it up
-        try {
-            Thread.sleep(20 * 1000);
-        } catch (InterruptedException ie) { // nop
-        }
-        I2PAppContext ctx = new I2PAppContext();
-        _log.debug("\n\n\n\nBegin test\n");
-        long negTime = 0;
-        try {
-            for (int i = 0; i < 5; i++) {
-                long startNeg = System.currentTimeMillis();
-                DHSessionKeyBuilder builder1 = new DHSessionKeyBuilder();
-                DHSessionKeyBuilder builder2 = new DHSessionKeyBuilder();
-                BigInteger pub1 = builder1.getMyPublicValue();
-                builder2.setPeerPublicValue(pub1);
-                BigInteger pub2 = builder2.getMyPublicValue();
-                builder1.setPeerPublicValue(pub2);
-                SessionKey key1 = builder1.getSessionKey();
-                SessionKey key2 = builder2.getSessionKey();
-                long endNeg = System.currentTimeMillis();
-                negTime += endNeg - startNeg;
-
-                if (!key1.equals(key2))
-                    _log.error("**ERROR: Keys do not match");
-                else
-                    _log.debug("**Success: Keys match");
-
-                byte iv[] = new byte[16];
-                RandomSource.getInstance().nextBytes(iv);
-                String origVal = "1234567890123456"; // 16 bytes max using AESEngine
-                byte enc[] = new byte[16];
-                byte dec[] = new byte[16];
-                ctx.aes().encrypt(origVal.getBytes(), 0, enc, 0, key1, iv, 16);
-                ctx.aes().decrypt(enc, 0, dec, 0, key2, iv, 16);
-                String tranVal = new String(dec);
-                if (origVal.equals(tranVal))
-                    _log.debug("**Success: D(E(val)) == val");
-                else
-                    _log.error("**ERROR: D(E(val)) != val [val=(" + tranVal + "), origVal=(" + origVal + ")");
-            }
-        } catch (InvalidPublicParameterException ippe) {
-            _log.error("Invalid dh", ippe);
-        }
-        _log.debug("Negotiation time for 5 runs: " + negTime + " @ " + negTime / 5l + "ms each");
-        try {
-            Thread.sleep(2000);
-        } catch (InterruptedException ie) { // nop
-        }
-    }
-******/
-
-    /**
-     * @since 0.9
-     */
-    public interface Factory {
-        /**
-         * Construct a new DH key builder
-         * or pulls a prebuilt one from the queue.
-         */
-        public DHSessionKeyBuilder getBuilder();
-
-        /**
-         * Return an unused DH key builder
-         * to be put back onto the queue for reuse.
-         *
-         * @param builder must not have a peerPublicValue set
-         * @since 0.9.16
-         */
-        public void returnUnused(DHSessionKeyBuilder builder);
-    }
-
-    /**
-     *  Try to keep DH pairs at the ready.
-     *  It's important to do this in a separate thread, because if we run out,
-     *  the pairs are generated in the NTCP Pumper thread,
-     *  and it can fall behind.
-     */
-    public static class PrecalcRunner extends I2PThread implements Factory {
-        private final I2PAppContext _context;
-        private final Log _log;
-        private final int _minSize;
-        private final int _maxSize;
-        private final int _calcDelay;
-        private final LinkedBlockingQueue<DHSessionKeyBuilder> _builders;
-        private volatile boolean _isRunning;
-
-        /** check periodically whether we have less than the minimum */
-        private long _checkDelay = 10 * 1000;
-
-        public PrecalcRunner(I2PAppContext ctx) {
-            super("DH Precalc");
-            _context = ctx;
-            _log = ctx.logManager().getLog(DHSessionKeyBuilder.class);
-            ctx.statManager().createRateStat("crypto.dhGeneratePublicTime", "How long it takes to create x and X", "Encryption", new long[] { 60*60*1000 });
-            ctx.statManager().createRateStat("crypto.dhCalculateSessionTime", "How long it takes to create the session key", "Encryption", new long[] { 60*60*1000 });        
-            ctx.statManager().createRateStat("crypto.DHUsed", "Need a DH from the queue", "Encryption", new long[] { 60*60*1000 });
-            ctx.statManager().createRateStat("crypto.DHReused", "Unused DH requeued", "Encryption", new long[] { 60*60*1000 });
-            ctx.statManager().createRateStat("crypto.DHEmpty", "DH queue empty", "Encryption", new long[] { 60*60*1000 });
-
-            // add to the defaults for every 128MB of RAM, up to 512MB
-            long maxMemory = SystemVersion.getMaxMemory();
-            int factor = (int) Math.max(1l, Math.min(4l, 1 + (maxMemory / (128*1024*1024l))));
-            if (SystemVersion.isSlow())
-                factor *= 2;
-            int defaultMin = DEFAULT_DH_PRECALC_MIN * factor;
-            int defaultMax = DEFAULT_DH_PRECALC_MAX * factor;
-            _minSize = ctx.getProperty(PROP_DH_PRECALC_MIN, defaultMin);
-            _maxSize = ctx.getProperty(PROP_DH_PRECALC_MAX, defaultMax);
-            _calcDelay = ctx.getProperty(PROP_DH_PRECALC_DELAY, DEFAULT_DH_PRECALC_DELAY);
-
-            if (_log.shouldLog(Log.DEBUG))
-                _log.debug("DH Precalc (minimum: " + _minSize + " max: " + _maxSize + ", delay: "
-                           + _calcDelay + ")");
-            _builders = new LinkedBlockingQueue<DHSessionKeyBuilder>(_maxSize);
-            if (!SystemVersion.isWindows())
-                setPriority(Thread.NORM_PRIORITY - 1);
-        }
-        
-        /**
-         *  Note that this stops the singleton precalc thread.
-         *  You don't want to do this if there are multiple routers in the JVM.
-         *  Fix this if you care. See Router.shutdown().
-         *  @since 0.8.8
-         */
-        public void shutdown() {
-            _isRunning = false;
-            this.interrupt();
-            _builders.clear();
-        }
-
-        public void run() {
-            try {
-                run2();
-            } catch (IllegalStateException ise) {
-                if (_isRunning)
-                    throw ise;
-                // else ignore, thread can be slow to shutdown on Android,
-                // PRNG gets stopped first and throws ISE
-            }
-        }
-
-        private void run2() {
-            _isRunning = true;
-            while (_isRunning) {
-                //long start = System.currentTimeMillis();
-                int startSize = getSize();
-                // Adjust delay
-                if (startSize <= (_minSize * 2 / 3) && _checkDelay > 1000)
-                    _checkDelay -= 1000;
-                else if (startSize > (_minSize * 3 / 2) && _checkDelay < 60*1000)
-                    _checkDelay += 1000;
-                if (startSize < _minSize) {
-                    // fill all the way up, do the check here so we don't
-                    // throw away one when full in addValues()
-                    while (getSize() < _maxSize && _isRunning) {
-                        long curStart = System.currentTimeMillis();
-                        if (!addBuilder(precalc()))
-                            break;
-                        long curCalc = System.currentTimeMillis() - curStart;
-                        // for some relief...
-                        if (!interrupted()) {
-                            try {
-                                Thread.sleep(Math.min(200, Math.max(10, _calcDelay + (curCalc * 3))));
-                            } catch (InterruptedException ie) {}
-                        }
-                    }
-                }
-                //long end = System.currentTimeMillis();
-                //int numCalc = curSize - startSize;
-                //if (numCalc > 0) {
-                //    if (_log.shouldLog(Log.DEBUG))
-                //        _log.debug("Precalced " + numCalc + " to " + curSize + " in "
-                //                   + (end - start - CALC_DELAY * numCalc) + "ms (not counting "
-                //                   + (CALC_DELAY * numCalc) + "ms relief).  now sleeping");
-                //}
-                if (!_isRunning)
-                    break;
-                try {
-                    Thread.sleep(_checkDelay);
-                } catch (InterruptedException ie) { // nop
-                }
-            }
-        }
-
-        /**
-         * Construct a new DH key builder
-         * or pulls a prebuilt one from the queue.
-         *
-         * @since 0.9 moved from DHSKB
-         */
-        public DHSessionKeyBuilder getBuilder() {
-            _context.statManager().addRateData("crypto.DHUsed", 1);
-            DHSessionKeyBuilder builder = _builders.poll();
-            if (builder == null) {
-                if (_log.shouldLog(Log.INFO)) _log.info("No more builders, creating one now");
-                _context.statManager().addRateData("crypto.DHEmpty", 1);
-                builder = precalc();
-                // stop sleeping, wake up, make some more
-                this.interrupt();
-            }
-            return builder;
-        }
-
-        private DHSessionKeyBuilder precalc() {
-            long start = System.currentTimeMillis();
-            DHSessionKeyBuilder builder = new DHSessionKeyBuilder(_context);
-            long end = System.currentTimeMillis();
-            long diff = end - start;
-            _context.statManager().addRateData("crypto.dhGeneratePublicTime", diff);
-            if (diff > 1000) {
-                if (_log.shouldLog(Log.WARN))
-                    _log.warn("Took more than a second (" + diff + "ms) to generate local DH value");
-            } else {
-                if (_log.shouldLog(Log.DEBUG)) _log.debug("Took " + diff + "ms to generate local DH value");
-            }
-            return builder;
-        }
-
-        /**
-         * Return an unused DH key builder
-         * to be put back onto the queue for reuse.
-         *
-         * @param builder must not have a peerPublicValue set
-         * @since 0.9.16
-         */
-        public void returnUnused(DHSessionKeyBuilder builder) {
-/*
-            if (builder.getPeerPublicValue() != null) {
-                _log.error("builder returned used", new Exception());
-                return;
-            }
-            if (_builders.offer(builder))
-                _context.statManager().addRateData("crypto.DHReused", 1);
-*/
-        }
-
-        /** @return true if successful, false if full */
-        private final boolean addBuilder(DHSessionKeyBuilder builder) {
-            return _builders.offer(builder);
-        }
-
-        private final int getSize() {
-            return _builders.size();
-        }
-
-    }
-    
-    public static class InvalidPublicParameterException extends I2PException {
-        public InvalidPublicParameterException() {
-            super();
-        }
-        public InvalidPublicParameterException(String msg) {
-            super(msg);
-        }
-        /** @since 0.9.35 */
-        public InvalidPublicParameterException(String msg, Throwable t) {
-            super(msg, t);
-        }
-    }
-}

router/java/src/net/i2p/router/transport/ntcp/InboundEstablishState.java

@@ -31,7 +31,6 @@ import net.i2p.data.router.RouterInfo;
 import net.i2p.router.Router;
 import net.i2p.router.RouterContext;
 import net.i2p.router.networkdb.kademlia.FloodfillNetworkDatabaseFacade;
-import net.i2p.router.transport.crypto.DHSessionKeyBuilder;
 import static net.i2p.router.transport.ntcp.OutboundNTCP2State.*;
 import net.i2p.util.Addresses;
 import net.i2p.util.ByteArrayStream;

router/java/src/net/i2p/router/transport/ntcp/NTCPTransport.java

@@ -50,7 +50,6 @@ import net.i2p.router.transport.TransportImpl;
 import net.i2p.router.transport.TransportManager;
 import net.i2p.router.transport.TransportUtil;
 import static net.i2p.router.transport.TransportUtil.IPv6Config.*;
-import net.i2p.router.transport.crypto.DHSessionKeyBuilder;
 import net.i2p.router.transport.crypto.X25519KeyFactory;
 import net.i2p.router.transport.udp.UDPTransport;
 import net.i2p.router.util.DecayingHashSet;
@@ -146,10 +145,9 @@ public class NTCPTransport extends TransportImpl {
     private final String _b64Ntcp2StaticIV;
 
     /**
-     *  @param dh unused, ignored
      *  @param xdh null to disable NTCP2
      */
-    public NTCPTransport(RouterContext ctx, DHSessionKeyBuilder.Factory dh, X25519KeyFactory xdh) {
+    public NTCPTransport(RouterContext ctx, X25519KeyFactory xdh) {
         super(ctx);
         _xdhFactory = xdh;
         _log = ctx.logManager().getLog(getClass());

router/java/src/net/i2p/router/transport/udp/EstablishmentManager.java

@@ -40,7 +40,6 @@ import net.i2p.router.OutNetMessage;
 import net.i2p.router.Router;
 import net.i2p.router.RouterContext;
 import net.i2p.router.transport.TransportUtil;
-import net.i2p.router.transport.crypto.DHSessionKeyBuilder;
 import static net.i2p.router.transport.udp.InboundEstablishState.InboundState.*;
 import static net.i2p.router.transport.udp.OutboundEstablishState.OutboundState.*;
 import static net.i2p.router.transport.udp.OutboundEstablishState2.IntroState.*;

router/java/test/junit/net/i2p/router/transport/crypto/DHSessionKeyBuilderTest.java

@@ -1,50 +0,0 @@
-package net.i2p.router.transport.crypto;
-
-/*
- * free (adj.): unencumbered; not under the control of others
- * Written by jrandom in 2003 and released into the public domain 
- * with no warranty of any kind, either expressed or implied.  
- * It probably won't  make your computer catch on fire, or eat 
- * your children, but it might.  Use at your own risk.
- *
- */
-
-import java.math.BigInteger;
-
-import junit.framework.TestCase;
-import net.i2p.I2PAppContext;
-import net.i2p.data.DataHelper;
-import net.i2p.data.SessionKey;
-import net.i2p.util.RandomSource;
-
-public class DHSessionKeyBuilderTest extends TestCase {
-    public void testDHSessionKeyBuilder(){
-        I2PAppContext ctx = new I2PAppContext();
-        for (int i = 0; i < 5; i++) {
-            DHSessionKeyBuilder builder1 = new DHSessionKeyBuilder();
-            DHSessionKeyBuilder builder2 = new DHSessionKeyBuilder();
-            BigInteger pub1 = builder1.getMyPublicValue();
-            BigInteger pub2 = builder2.getMyPublicValue();
-            try {
-                builder2.setPeerPublicValue(pub1);
-                builder1.setPeerPublicValue(pub2);
-            } catch (DHSessionKeyBuilder.InvalidPublicParameterException ippe) {
-                assertTrue(ippe.getMessage(), true);
-            }
-            SessionKey key1 = builder1.getSessionKey();
-            SessionKey key2 = builder2.getSessionKey();
-
-            assertEquals(key1, key2);
-
-            byte iv[] = new byte[16];
-            RandomSource.getInstance().nextBytes(iv);
-            String origVal = "1234567890123456"; // 16 bytes max using AESEngine
-            byte enc[] = new byte[16];
-            byte dec[] = new byte[16];
-            ctx.aes().encrypt(DataHelper.getASCII(origVal), 0, enc, 0, key1, iv, 16);
-            ctx.aes().decrypt(enc, 0, dec, 0, key2, iv, 16);
-            String tranVal = new String(dec);
-            assertEquals(origVal, tranVal);
-        }
-    }
-}