@Override
public DeterministicKeyChain toDecrypted(KeyParameter aesKey) {
checkState(getKeyCrypter() != null, "Key chain not encrypted");
checkState(seed != null, "Can't decrypt a watching chain");
checkState(seed.isEncrypted());
String passphrase = DEFAULT_PASSPHRASE_FOR_MNEMONIC; // FIXME allow non-empty passphrase
DeterministicSeed decSeed = seed.decrypt(getKeyCrypter(), passphrase, aesKey);
DeterministicKeyChain chain = new DeterministicKeyChain(decSeed);
// Now double check that the keys match to catch the case where the key is wrong but padding
// didn't catch it.
if (!chain.getWatchingKey().getPubKeyPoint().equals(getWatchingKey().getPubKeyPoint()))
throw new KeyCrypterException("Provided AES key is wrong");
chain.lookaheadSize = lookaheadSize;
// Now copy the (pubkey only) leaf keys across to avoid rederiving them. The private key bytes
// are missing
// anyway so there's nothing to decrypt.
for (ECKey eckey : basicKeyChain.getKeys()) {
DeterministicKey key = (DeterministicKey) eckey;
if (key.getPath().size() != 3) continue; // Not a leaf key.
checkState(key.isEncrypted());
DeterministicKey parent =
chain.hierarchy.get(checkNotNull(key.getParent()).getPath(), false, false);
// Clone the key to the new decrypted hierarchy.
key = new DeterministicKey(key.getPubOnly(), parent);
chain.hierarchy.putKey(key);
chain.basicKeyChain.importKey(key);
}
chain.issuedExternalKeys = issuedExternalKeys;
chain.issuedInternalKeys = issuedInternalKeys;
return chain;
}
/**
* Pre-generate enough keys to reach the lookahead size, but only if there are more than the
* lookaheadThreshold to be generated, so that the Bloom filter does not have to be regenerated
* that often.
*
* <p>The returned mutable list of keys must be inserted into the basic key chain.
*/
private List<DeterministicKey> maybeLookAhead(
DeterministicKey parent, int issued, int lookaheadSize, int lookaheadThreshold) {
checkState(lock.isHeldByCurrentThread());
final int numChildren = hierarchy.getNumChildren(parent.getPath());
final int needed = issued + lookaheadSize + lookaheadThreshold - numChildren;
if (needed <= lookaheadThreshold) return new ArrayList<DeterministicKey>();
log.info(
"{} keys needed for {} = {} issued + {} lookahead size + {} lookahead threshold - {} num children",
needed,
parent.getPathAsString(),
issued,
lookaheadSize,
lookaheadThreshold,
numChildren);
List<DeterministicKey> result = new ArrayList<DeterministicKey>(needed);
long now = System.currentTimeMillis();
int nextChild = numChildren;
for (int i = 0; i < needed; i++) {
DeterministicKey key = HDKeyDerivation.deriveThisOrNextChildKey(parent, nextChild);
key = key.getPubOnly();
hierarchy.putKey(key);
result.add(key);
nextChild = key.getChildNumber().num() + 1;
}
log.info("Took {} msec", System.currentTimeMillis() - now);
return result;
}
// For use in encryption.
private DeterministicKeyChain(
KeyCrypter crypter, KeyParameter aesKey, DeterministicKeyChain chain) {
// Can't encrypt a watching chain.
checkNotNull(chain.rootKey);
checkNotNull(chain.seed);
checkArgument(!chain.rootKey.isEncrypted(), "Chain already encrypted");
this.issuedExternalKeys = chain.issuedExternalKeys;
this.issuedInternalKeys = chain.issuedInternalKeys;
this.lookaheadSize = chain.lookaheadSize;
this.lookaheadThreshold = chain.lookaheadThreshold;
this.seed = chain.seed.encrypt(crypter, aesKey);
basicKeyChain = new BasicKeyChain(crypter);
// The first number is the "account number" but we don't use that feature.
rootKey = chain.rootKey.encrypt(crypter, aesKey, null);
hierarchy = new DeterministicHierarchy(rootKey);
basicKeyChain.importKey(rootKey);
DeterministicKey account = encryptNonLeaf(aesKey, chain, rootKey, ACCOUNT_ZERO_PATH);
externalKey = encryptNonLeaf(aesKey, chain, account, EXTERNAL_PATH);
internalKey = encryptNonLeaf(aesKey, chain, account, INTERNAL_PATH);
// Now copy the (pubkey only) leaf keys across to avoid rederiving them. The private key bytes
// are missing
// anyway so there's nothing to encrypt.
for (ECKey eckey : chain.basicKeyChain.getKeys()) {
DeterministicKey key = (DeterministicKey) eckey;
if (key.getPath().size() != 3) continue; // Not a leaf key.
DeterministicKey parent =
hierarchy.get(checkNotNull(key.getParent()).getPath(), false, false);
// Clone the key to the new encrypted hierarchy.
key = new DeterministicKey(key.getPubOnly(), parent);
hierarchy.putKey(key);
basicKeyChain.importKey(key);
}
}
