/**
* Creates a program that requires at least N of the given keys to sign, using OP_CHECKMULTISIG.
*/
public static Script createMultiSigOutputScript(int threshold, List<ECKey> pubkeys) {
checkArgument(threshold > 0);
checkArgument(threshold <= pubkeys.size());
checkArgument(pubkeys.size() <= 16); // That's the max we can represent with a single opcode.
ScriptBuilder builder = new ScriptBuilder();
builder.smallNum(threshold);
for (ECKey key : pubkeys) {
builder.data(key.getPubKey());
}
builder.smallNum(pubkeys.size());
builder.op(OP_CHECKMULTISIG);
return builder.build();
}
/**
* Create a program that satisfies an OP_CHECKMULTISIG program, using pre-encoded signatures.
* Optionally, appends the script program bytes if spending a P2SH output.
*/
public static Script createMultiSigInputScriptBytes(
List<byte[]> signatures, @Nullable byte[] multisigProgramBytes) {
checkArgument(signatures.size() <= 16);
ScriptBuilder builder = new ScriptBuilder();
builder.smallNum(
0); // Work around a bug in CHECKMULTISIG that is now a required part of the protocol.
for (byte[] signature : signatures) builder.data(signature);
if (multisigProgramBytes != null) builder.data(multisigProgramBytes);
return builder.build();
}
