/*
* Copyright by the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.bitcoinj.wallet;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.protobuf.ByteString;
import org.bitcoinj.core.BloomFilter;
import org.bitcoinj.core.ECKey;
import org.bitcoinj.core.NetworkParameters;
import org.bitcoinj.core.Utils;
import org.bitcoinj.crypto.DeterministicKey;
import org.bitcoinj.crypto.KeyCrypter;
import org.bitcoinj.script.Script;
import org.bitcoinj.script.ScriptBuilder;
import java.security.SecureRandom;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.annotation.Nullable;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.Lists.newArrayList;
/**
* <p>A multi-signature keychain using synchronized HD keys (a.k.a HDM)</p>
* <p>This keychain keeps track of following keychains that follow the account key of this keychain.
* You can get P2SH addresses to receive coins to from this chain. The threshold - sigsRequiredToSpend
* specifies how many signatures required to spend transactions for this married keychain. This value should not exceed
* total number of keys involved (one followed key plus number of following keys), otherwise IllegalArgumentException
* will be thrown.</p>
* <p>IMPORTANT: As of Bitcoin Core 0.9 all multisig transactions which require more than 3 public keys are non-standard
* and such spends won't be processed by peers with default settings, essentially making such transactions almost
* nonspendable</p>
* <p>This method will throw an IllegalStateException, if the keychain is already married or already has leaf keys
* issued.</p>
*/
public class MarriedKeyChain extends DeterministicKeyChain {
// The map holds P2SH redeem script and corresponding ECKeys issued by this KeyChainGroup (including lookahead)
// mapped to redeem script hashes.
private LinkedHashMap<ByteString, RedeemData> marriedKeysRedeemData = new LinkedHashMap<ByteString, RedeemData>();
private List<DeterministicKeyChain> followingKeyChains;
/** Builds a {@link MarriedKeyChain} */
public static class Builder<T extends Builder<T>> extends DeterministicKeyChain.Builder<T> {
private List<DeterministicKey> followingKeys;
private int threshold;
protected Builder() {
}
public T followingKeys(List<DeterministicKey> followingKeys) {
this.followingKeys = followingKeys;
return self();
}
public T followingKeys(DeterministicKey followingKey, DeterministicKey ...followingKeys) {
this.followingKeys = Lists.asList(followingKey, followingKeys);
return self();
}
/**
* Threshold, or <code>(followingKeys.size() + 1) / 2 + 1)</code> (majority) if unspecified.</p>
* <p>IMPORTANT: As of Bitcoin Core 0.9 all multisig transactions which require more than 3 public keys are non-standard
* and such spends won't be processed by peers with default settings, essentially making such transactions almost
* nonspendable</p>
*/
public T threshold(int threshold) {
this.threshold = threshold;
return self();
}
@Override
public MarriedKeyChain build() {
checkState(random != null || entropy != null || seed != null || watchingKey!= null, "Must provide either entropy or random or seed or watchingKey");
checkNotNull(followingKeys, "followingKeys must be provided");
MarriedKeyChain chain;
if (threshold == 0)
threshold = (followingKeys.size() + 1) / 2 + 1;
if (random != null) {
chain = new MarriedKeyChain(random, bits, getPassphrase(), seedCreationTimeSecs);
} else if (entropy != null) {
chain = new MarriedKeyChain(entropy, getPassphrase(), seedCreationTimeSecs);
} else if (seed != null) {
seed.setCreationTimeSeconds(seedCreationTimeSecs);
chain = new MarriedKeyChain(seed);
} else {
watchingKey.setCreationTimeSeconds(seedCreationTimeSecs);
chain = new MarriedKeyChain(watchingKey);
}
chain.addFollowingAccountKeys(followingKeys, threshold);
return chain;
}
}
public static Builder<?> builder() {
return new Builder();
}
// Protobuf deserialization constructors
MarriedKeyChain(DeterministicKey accountKey) {
super(accountKey, false);
}
MarriedKeyChain(DeterministicSeed seed, KeyCrypter crypter) {
super(seed, crypter);
}
// Builder constructors
private MarriedKeyChain(SecureRandom random, int bits, String passphrase, long seedCreationTimeSecs) {
super(random, bits, passphrase, seedCreationTimeSecs);
}
private MarriedKeyChain(byte[] entropy, String passphrase, long seedCreationTimeSecs) {
super(entropy, passphrase, seedCreationTimeSecs);
}
private MarriedKeyChain(DeterministicSeed seed) {
super(seed);
}
void setFollowingKeyChains(List<DeterministicKeyChain> followingKeyChains) {
checkArgument(!followingKeyChains.isEmpty());
this.followingKeyChains = followingKeyChains;
}
@Override
public boolean isMarried() {
return true;
}
/** Create a new married key and return the matching output script */
@Override
public Script freshOutputScript(KeyPurpose purpose) {
DeterministicKey followedKey = getKey(purpose);
ImmutableList.Builder<ECKey> keys = ImmutableList.<ECKey>builder().add(followedKey);
for (DeterministicKeyChain keyChain : followingKeyChains) {
DeterministicKey followingKey = keyChain.getKey(purpose);
checkState(followedKey.getChildNumber().equals(followingKey.getChildNumber()), "Following keychains should be in sync");
keys.add(followingKey);
}
List<ECKey> marriedKeys = keys.build();
Script redeemScript = ScriptBuilder.createRedeemScript(sigsRequiredToSpend, marriedKeys);
return ScriptBuilder.createP2SHOutputScript(redeemScript);
}
private List<ECKey> getMarriedKeysWithFollowed(DeterministicKey followedKey) {
ImmutableList.Builder<ECKey> keys = ImmutableList.builder();
for (DeterministicKeyChain keyChain : followingKeyChains) {
keyChain.maybeLookAhead();
keys.add(keyChain.getKeyByPath(followedKey.getPath()));
}
keys.add(followedKey);
return keys.build();
}
/** Get the redeem data for a key in this married chain */
@Override
public RedeemData getRedeemData(DeterministicKey followedKey) {
List<ECKey> marriedKeys = getMarriedKeysWithFollowed(followedKey);
Script redeemScript = ScriptBuilder.createRedeemScript(sigsRequiredToSpend, marriedKeys);
return RedeemData.of(marriedKeys, redeemScript);
}
private void addFollowingAccountKeys(List<DeterministicKey> followingAccountKeys, int sigsRequiredToSpend) {
checkArgument(sigsRequiredToSpend <= followingAccountKeys.size() + 1, "Multisig threshold can't exceed total number of keys");
checkState(numLeafKeysIssued() == 0, "Active keychain already has keys in use");
checkState(followingKeyChains == null);
List<DeterministicKeyChain> followingKeyChains = Lists.newArrayList();
for (DeterministicKey key : followingAccountKeys) {
checkArgument(key.getPath().size() == getAccountPath().size(), "Following keys have to be account keys");
DeterministicKeyChain chain = DeterministicKeyChain.watchAndFollow(key);
if (lookaheadSize >= 0)
chain.setLookaheadSize(lookaheadSize);
if (lookaheadThreshold >= 0)
chain.setLookaheadThreshold(lookaheadThreshold);
followingKeyChains.add(chain);
}
this.sigsRequiredToSpend = sigsRequiredToSpend;
this.followingKeyChains = followingKeyChains;
}
@Override
public void setLookaheadSize(int lookaheadSize) {
lock.lock();
try {
super.setLookaheadSize(lookaheadSize);
if (followingKeyChains != null) {
for (DeterministicKeyChain followingChain : followingKeyChains) {
followingChain.setLookaheadSize(lookaheadSize);
}
}
} finally {
lock.unlock();
}
}
@Override
public List<Protos.Key> serializeToProtobuf() {
List<Protos.Key> result = newArrayList();
lock.lock();
try {
for (DeterministicKeyChain chain : followingKeyChains) {
result.addAll(chain.serializeMyselfToProtobuf());
}
result.addAll(serializeMyselfToProtobuf());
} finally {
lock.unlock();
}
return result;
}
@Override
protected void formatAddresses(boolean includePrivateKeys, NetworkParameters params, StringBuilder builder2) {
for (DeterministicKeyChain followingChain : followingKeyChains)
builder2.append("Following chain: ").append(followingChain.getWatchingKey().serializePubB58(params))
.append('\n');
builder2.append('\n');
for (RedeemData redeemData : marriedKeysRedeemData.values())
formatScript(ScriptBuilder.createP2SHOutputScript(redeemData.redeemScript), builder2, params);
}
private void formatScript(Script script, StringBuilder builder, NetworkParameters params) {
builder.append(" addr:");
builder.append(script.getToAddress(params));
builder.append(" hash160:");
builder.append(Utils.HEX.encode(script.getPubKeyHash()));
if (script.getCreationTimeSeconds() > 0)
builder.append(" creationTimeSeconds:").append(script.getCreationTimeSeconds());
builder.append('\n');
}
@Override
public void maybeLookAheadScripts() {
super.maybeLookAheadScripts();
int numLeafKeys = getLeafKeys().size();
checkState(marriedKeysRedeemData.size() <= numLeafKeys, "Number of scripts is greater than number of leaf keys");
if (marriedKeysRedeemData.size() == numLeafKeys)
return;
maybeLookAhead();
for (DeterministicKey followedKey : getLeafKeys()) {
RedeemData redeemData = getRedeemData(followedKey);
Script scriptPubKey = ScriptBuilder.createP2SHOutputScript(redeemData.redeemScript);
marriedKeysRedeemData.put(ByteString.copyFrom(scriptPubKey.getPubKeyHash()), redeemData);
}
}
@Nullable
@Override
public RedeemData findRedeemDataByScriptHash(ByteString bytes) {
return marriedKeysRedeemData.get(bytes);
}
@Override
public BloomFilter getFilter(int size, double falsePositiveRate, long tweak) {
lock.lock();
BloomFilter filter;
try {
filter = new BloomFilter(size, falsePositiveRate, tweak);
for (Map.Entry<ByteString, RedeemData> entry : marriedKeysRedeemData.entrySet()) {
filter.insert(entry.getKey().toByteArray());
filter.insert(entry.getValue().redeemScript.getProgram());
}
} finally {
lock.unlock();
}
return filter;
}
@Override
public int numBloomFilterEntries() {
maybeLookAhead();
return getLeafKeys().size() * 2;
}
}