/** Create a program that satisfies an OP_CHECKMULTISIG program. */
public static Script createMultiSigInputScript(List<TransactionSignature> signatures) {
List<byte[]> sigs = new ArrayList<byte[]>(signatures.size());
for (TransactionSignature signature : signatures) {
sigs.add(signature.encodeToPeercoin());
}
return createMultiSigInputScriptBytes(sigs, null);
}
/**
* Create a program that satisfies a pay-to-script hashed OP_CHECKMULTISIG program. If given
* signature list is null, incomplete scriptSig will be created with OP_0 instead of signatures
*/
public static Script createP2SHMultiSigInputScript(
@Nullable List<TransactionSignature> signatures, Script multisigProgram) {
List<byte[]> sigs = new ArrayList<byte[]>();
if (signatures == null) {
// create correct number of empty signatures
int numSigs = multisigProgram.getNumberOfSignaturesRequiredToSpend();
for (int i = 0; i < numSigs; i++) sigs.add(new byte[] {});
} else {
for (TransactionSignature signature : signatures) {
sigs.add(signature.encodeToPeercoin());
}
}
return createMultiSigInputScriptBytes(sigs, multisigProgram.getProgram());
}
@Override
public boolean signInputs(ProposedTransaction propTx, KeyBag keyBag) {
Transaction tx = propTx.partialTx;
int numInputs = tx.getInputs().size();
for (int i = 0; i < numInputs; i++) {
TransactionInput txIn = tx.getInput(i);
if (txIn.getConnectedOutput() == null) {
log.warn("Missing connected output, assuming input {} is already signed.", i);
continue;
}
try {
// We assume if its already signed, its hopefully got a SIGHASH type that will not
// invalidate when
// we sign missing pieces (to check this would require either assuming any signatures are
// signing
// standard output types or a way to get processed signatures out of script execution)
txIn.getScriptSig().correctlySpends(tx, i, txIn.getConnectedOutput().getScriptPubKey());
log.warn(
"Input {} already correctly spends output, assuming SIGHASH type used will be safe and skipping signing.",
i);
continue;
} catch (ScriptException e) {
// Expected.
}
RedeemData redeemData = txIn.getConnectedRedeemData(keyBag);
Script scriptPubKey = txIn.getConnectedOutput().getScriptPubKey();
// For P2SH inputs we need to share derivation path of the signing key with other signers, so
// that they
// use correct key to calculate their signatures.
// Married keys all have the same derivation path, so we can safely just take first one here.
ECKey pubKey = redeemData.keys.get(0);
if (pubKey instanceof DeterministicKey)
propTx.keyPaths.put(scriptPubKey, (((DeterministicKey) pubKey).getPath()));
ECKey key;
// locate private key in redeem data. For pay-to-address and pay-to-key inputs RedeemData will
// always contain
// only one key (with private bytes). For P2SH inputs RedeemData will contain multiple keys,
// one of which MAY
// have private bytes
if (redeemData == null || (key = redeemData.getFullKey()) == null) {
log.warn("No local key found for input {}", i);
continue;
}
Script inputScript = txIn.getScriptSig();
// script here would be either a standard CHECKSIG program for pay-to-address or pay-to-pubkey
// inputs or
// a CHECKMULTISIG program for P2SH inputs
byte[] script = redeemData.redeemScript.getProgram();
try {
TransactionSignature signature =
tx.calculateSignature(i, key, script, Transaction.SigHash.ALL, false);
// at this point we have incomplete inputScript with OP_0 in place of one or more
// signatures. We already
// have calculated the signature using the local key and now need to insert it in the
// correct place
// within inputScript. For pay-to-address and pay-to-key script there is only one signature
// and it always
// goes first in an inputScript (sigIndex = 0). In P2SH input scripts we need to figure out
// our relative
// position relative to other signers. Since we don't have that information at this point,
// and since
// we always run first, we have to depend on the other signers rearranging the signatures as
// needed.
// Therefore, always place as first signature.
int sigIndex = 0;
inputScript =
scriptPubKey.getScriptSigWithSignature(
inputScript, signature.encodeToPeercoin(), sigIndex);
txIn.setScriptSig(inputScript);
} catch (ECKey.KeyIsEncryptedException e) {
throw e;
} catch (ECKey.MissingPrivateKeyException e) {
log.warn("No private key in keypair for input {}", i);
}
}
return true;
}
/**
* Creates a scriptSig that can redeem a pay-to-pubkey output. If given signature is null,
* incomplete scriptSig will be created with OP_0 instead of signature
*/
public static Script createInputScript(@Nullable TransactionSignature signature) {
byte[] sigBytes = signature != null ? signature.encodeToPeercoin() : new byte[] {};
return new ScriptBuilder().data(sigBytes).build();
}
