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Commit ee466789 authored by zzz's avatar zzz
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Crypto: RatchetTagSet using SparseArray

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router/java/src/net/i2p/router/crypto/ratchet/RatchetTagSet.java 0 → 100644
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package net.i2p.router.crypto.ratchet;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import com.southernstorm.noise.protocol.HandshakeState;
import net.i2p.I2PAppContext;
import net.i2p.crypto.HKDF;
import net.i2p.crypto.TagSetHandle;
import net.i2p.data.Base64;
import net.i2p.data.SessionKey;
/**
* A tagset class for one direction, either inbound or outbound.
*
* For outbound, uses very little memory. Tags and keys are generated on demand.
* See proposal 144.
*
* For inbound, generates the tags in advance, maintaining minSize lookahead.
* Keys are generated as required.
*
* Caller must synch on all methods.
*
* @since 0.9.44
*/
class RatchetTagSet implements TagSetHandle {
private final SessionTagListener _lsnr;
private final SessionKey _key;
private final HandshakeState _state;
// We use object for tags because we must do indexOfValueByValue()
private final SparseArray<RatchetSessionTag> _sessionTags;
// We use byte[] for key to save space, because we don't need indexOfValueByValue()
private final SparseArray<byte[]> _sessionKeys;
private final HKDF hkdf;
private final long _date;
private final int _id;
private final int _originalSize;
private final int _maxSize;
private boolean _acked;
private final byte[] _nextRootKey;
private final byte[] _sesstag_ck;
private final byte[] _sesstag_constant;
private final byte[] _symmkey_ck;
private final byte[] _symmkey_constant;
private int _lastTag = -1;
private int _lastKey = -1;
private static final String INFO_1 = "KDFDHRatchetStep";
private static final String INFO_2 = "TagAndKeyGenKeys";
private static final String INFO_3 = "STInitialization";
private static final String INFO_4 = "SessionTagKeyGen";
private static final String INFO_5 = "SymmetricRatchet";
private static final byte[] ZEROLEN = new byte[0];
private static final int TAGLEN = 8;
/**
* Outbound Tagset
*
* @param date For outbound: creation time
*/
public RatchetTagSet(HKDF hkdf, SessionKey rootKey, SessionKey data,
long date, int id) {
this(hkdf, null, null, rootKey, data, date, id, false, 0, 0);
}
/**
* Inbound NSR Tagset
*
* @param date For inbound: when the TagSet will expire
*/
public RatchetTagSet(HKDF hkdf, SessionTagListener lsnr, HandshakeState state, SessionKey rootKey, SessionKey data,
long date, int id, int minSize, int maxSize) {
this(hkdf, lsnr, state, rootKey, data, date, id, true, minSize, maxSize);
}
/**
* Inbound ES Tagset
*
* @param date For inbound: when the TagSet will expire
*/
public RatchetTagSet(HKDF hkdf, SessionTagListener lsnr, SessionKey rootKey, SessionKey data,
long date, int id, int minSize, int maxSize) {
this(hkdf, lsnr, null, rootKey, data, date, id, true, minSize, maxSize);
}
/**
* @param date For inbound: when the TagSet will expire; for outbound: creation time
*/
private RatchetTagSet(HKDF hkdf, SessionTagListener lsnr, HandshakeState state, SessionKey rootKey, SessionKey data,
long date, int id, boolean isInbound, int minSize, int maxSize) {
_lsnr = lsnr;
_state = state;
_key = rootKey;
_date = date;
_id = id;
_originalSize = minSize;
_maxSize = maxSize;
_nextRootKey = new byte[32];
byte[] ck = new byte[32];
_sesstag_ck = new byte[32];
_sesstag_constant = new byte[32];
_symmkey_ck = new byte[32];
_symmkey_constant = ZEROLEN;
this.hkdf = hkdf;
hkdf.calculate(rootKey.getData(), data.getData(), INFO_1, _nextRootKey, ck, 0);
hkdf.calculate(ck, ZEROLEN, INFO_2, _sesstag_ck, _symmkey_ck, 0);
hkdf.calculate(_sesstag_ck, ZEROLEN, INFO_3, _sesstag_ck, _sesstag_constant, 0);
if (isInbound) {
_sessionTags = new SparseArray<RatchetSessionTag>(minSize);
if (state == null)
_sessionKeys = new SparseArray<byte[]>(minSize);
else
_sessionKeys = null;
for (int i = 0; i < minSize; i++) {
storeNextTag();
}
} else {
_sessionTags = null;
_sessionKeys = null;
}
System.out.println("DH INIT, rootKey = " + rootKey.toBase64() +
" data = " + data.toBase64());
}
public void clear() {
if (_sessionTags != null)
_sessionTags.clear();
if (_sessionKeys != null)
_sessionKeys.clear();
}
/**
* The identifier for the session..
* Not used for cryptographic operations after setup.
*/
public SessionKey getAssociatedKey() {
return _key;
}
/**
* For inbound NSR only, else null.
* MUST be cloned before processing NSR.
*/
public HandshakeState getHandshakeState() {
return _state;
}
/**
* For inbound: when the TagSet will expire; for outbound: creation time
*/
public long getDate() {
return _date;
}
/** for debugging */
public int getOriginalSize() {
return 0;
}
public int size() {
return _sessionTags != null ? _sessionTags.size() : 0;
}
/**
* tags still available
* inbound only
* testing only
*/
public List<RatchetSessionTag> getTags() {
if (_sessionTags == null)
return Collections.emptyList();
int sz = _sessionTags.size();
List<RatchetSessionTag> rv = new ArrayList<RatchetSessionTag>(sz);
for (int i = 0; i < sz; i++) {
rv.add(_sessionTags.valueAt(i));
}
return rv;
}
/**
* first tag still available, or null
* inbound only
* testing only
*/
public RatchetSessionTag getFirstTag() {
if (_sessionTags == null)
throw new IllegalStateException("Outbound tagset");
if (_sessionTags.size() <= 0)
return null;
return _sessionTags.valueAt(0);
}
/**
* inbound only
* @return associated SessionKey or null if not found.
*/
public SessionKeyAndNonce consume(RatchetSessionTag tag) {
if (_sessionTags == null)
throw new IllegalStateException("Outbound tagset");
// linear search for tag
// == not equals
int idx = _sessionTags.indexOfValueByValue(tag);
if (idx < 0) {
System.out.println("Tag not found " + Base64.encode(tag.getData()));
System.out.println("Remaining tags: " + getTags());
return null;
}
int tagnum = _sessionTags.keyAt(idx);
_sessionTags.removeAt(idx);
// now get the key
int kidx = _sessionKeys.indexOfKey(tagnum);
if (kidx >= 0) {
// already calculated
byte[] rv = _sessionKeys.valueAt(kidx);
_sessionKeys.removeAt(kidx);
addTags(tagnum);
return new SessionKeyAndNonce(rv, tagnum);
} else if (tagnum > _lastKey) {
// if there's any gaps, catch up and store
for (int i = _lastKey + 1; i < tagnum; i++) {
//System.out.println("Fill in key gap at " + i);
_sessionKeys.put(i, consumeNextKey().getData());
}
SessionKeyAndNonce rv = consumeNextKey();
addTags(tagnum);
return rv;
} else {
// dup or some other error
System.out.println("No key found for tag " + Base64.encode(tag.getData()) + " at index " + idx +
" tagnum = " + tagnum + " lastkey = " + _lastKey);
return null;
}
}
private void addTags(int usedTagNumber) {
// add as many as we need to maintain minSize from the tag used
int remaining = _lastTag - usedTagNumber;
int toAdd = _originalSize - remaining;
if (toAdd > 0) {
//System.out.println("Extending tags by " + toAdd);
for (int i = 0; i < toAdd; i++) {
storeNextTag();
}
}
// trim if too big
int toTrim = _sessionTags.size() - _maxSize;
if (toTrim > 0) {
System.out.println("Trimming tags by " + toTrim);
for (int i = 0; i < toTrim; i++) {
int tagnum = _sessionTags.keyAt(i);
int kidx = _sessionKeys.indexOfKey(tagnum);
if (kidx >= 0)
_sessionKeys.removeAt(kidx);
if (_lsnr != null)
_lsnr.expireTag(_sessionTags.valueAt(i), this);
}
_sessionTags.removeAtRange(0, toTrim);
}
}
private void storeNextTag() {
RatchetSessionTag tag = consumeNext();
_sessionTags.put(_lastTag, tag);
if (_lsnr != null)
_lsnr.addTag(tag, this);
}
/**
* For outbound only.
* Call before consumeNextKey();
*
* @return a tag or null
*/
public RatchetSessionTag consumeNext() {
byte[] tmp = new byte[32];
hkdf.calculate(_sesstag_ck, _sesstag_constant, INFO_4, _sesstag_ck, tmp, 0);
byte[] tag = new byte[TAGLEN];
System.arraycopy(tmp, 0, tag, 0, TAGLEN);
_lastTag++;
return new RatchetSessionTag(tag);
}
/**
* For outbound only.
* Call after consumeNextTag();
*
* @return a key and nonce, non-null
*/
public SessionKeyAndNonce consumeNextKey() {
byte[] key = new byte[32];
hkdf.calculate(_symmkey_ck, _symmkey_constant, INFO_5, _symmkey_ck, key, 0);
_lastKey++;
return new SessionKeyAndNonce(key, _lastKey);
}
/**
* For outbound only.
*/
public void setAcked() { _acked = true; }
/**
* For outbound only.
*/
public boolean getAcked() { return _acked; }
/** for debugging */
public int getID() {
return _id;
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder(256);
buf.append("TagSet #").append(_id).append(" created: ").append(new Date(_date));
int sz = size();
buf.append(" Size: ").append(sz);
buf.append('/').append(getOriginalSize());
buf.append(" Acked? ").append(_acked);
for (int i = 0; i < sz; i++) {
int n = _sessionTags.keyAt(i);
RatchetSessionTag tag = _sessionTags.valueAt(i);
byte[] key = _sessionKeys.get(n);
buf.append("\n " + n + '\t' + Base64.encode(tag.getData()));
if (key != null)
buf.append('\t' + Base64.encode(key));
else
buf.append("\tdeferred");
}
return buf.toString();
}
/****
public static void main(String[] args) {
SessionKey k1 = new SessionKey(new byte[32]);
SessionKey k2 = new SessionKey(new byte[32]);
System.out.println("Send test");
HKDF hkdf = new HKDF(I2PAppContext.getGlobalContext());
RatchetTagSet rts = new RatchetTagSet(hkdf, k1, k2, 0, 0);
System.out.println("TAGNUM\tTAG\t\tKEY");
for (int i = 0; i < 20; i++) {
RatchetSessionTag tag = rts.consumeNext();
SessionKey key = rts.consumeNextKey();
System.out.println(i + "\t" + Base64.encode(tag.getData()) + '\t' + Base64.encode(key.getData()));
}
System.out.println("Size now: " + rts.size());
System.out.println("");
System.out.println("Receive test in-order");
rts = new RatchetTagSet(hkdf, null, k1, k2, 0, 0, 10, 50);
System.out.println("Size now: " + rts.size());
List<RatchetSessionTag> tags = rts.getTags();
int j = 0;
System.out.println("TAGNUM\tTAG\t\tKEY");
for (RatchetSessionTag tag : tags) {
SessionKey key = rts.consume(tag);
if (key != null)
System.out.println(j++ + "\t" + Base64.encode(tag.getData()) + '\t' + Base64.encode(key.getData()));
else
System.out.println(j++ + "\t" + Base64.encode(tag.getData()) + "\t NOT FOUND");
}
for (int i = 11; i <= 20; i++) {
RatchetSessionTag tag = rts.getFirstTag();
SessionKey key = rts.consume(tag);
if (key != null)
System.out.println(i + "\t" + Base64.encode(tag.getData()) + '\t' + Base64.encode(key.getData()));
else
System.out.println(i + "\t" + Base64.encode(tag.getData()) + "\t NOT FOUND");
}
System.out.println("Size now: " + rts.size());
System.out.println("");
System.out.println("Receive test out of order");
rts = new RatchetTagSet(hkdf, null, k1, k2, 0, 0, 10, 50);
System.out.println("Size now: " + rts.size());
tags = rts.getTags();
List<RatchetSessionTag> origtags = new ArrayList<RatchetSessionTag>(tags);
Collections.shuffle(tags);
System.out.println("TAGNUM\tTAG\t\tKEY");
for (RatchetSessionTag tag : tags) {
int idx = origtags.indexOf(tag);
SessionKey key = rts.consume(tag);
if (key != null) {
System.out.println(idx + "\t" + Base64.encode(tag.getData()) + '\t' + Base64.encode(key.getData()));
//System.out.println("Remaining tags: " + rts.getTags());
} else {
System.out.println(idx + "\t" + Base64.encode(tag.getData()) + "\t NOT FOUND");
}
}
for (int i = 11; i <= 20; i++) {
RatchetSessionTag tag = rts.getFirstTag();
SessionKey key = rts.consume(tag);
if (key != null)
System.out.println(i + "\t" + Base64.encode(tag.getData()) + '\t' + Base64.encode(key.getData()));
else
System.out.println(i + "\t" + Base64.encode(tag.getData()) + "\t NOT FOUND");
}
System.out.println("Size now: " + rts.size());
System.out.println(rts.toString());
}
****/
}
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