This is what you need to do to create a wallet where you manage 1 key
and other parties manage the 2 other keys:
NetworkParameters params = TestNet3Params.get();
DeterministicKey followingKey1 =
DeterministicKey.deserializeB58("tpubSuppliedByThirdParty1", params);
DeterministicKey followingKey2 =
DeterministicKey.deserializeB58("tpubSuppliedByThirdParty2", params);
MarriedKeyChain chain = MarriedKeyChain.builder()
.random(new SecureRandom())
.followingKeys(followingKey1, followingKey2)
.threshold(2).build();
wallet.addAndActivateHDChain(chain);
wallet..freshReceiveAddress(); // Returns a p2sh address starting with "2"
If you don't have a third party to provide the extended pubkeys yet,
you can generate them yourself (for testing purposes):
DeterministicKeyChain keyChain1 = new DeterministicKeyChain(new SecureRandom());
String tpubSuppliedByThirdParty1 =
keyChain.getWatchingKey().serializePubB58(params);
Once you have funds on your wallet, you can spend them by doing:
// Generate a partially signed tx
Wallet.SendRequest req = Wallet.SendRequest.to(new Address(params,
"destinationAddress"), Coin.MILLICOIN);
req.missingSigsMode = Wallet.MissingSigsMode.USE_OP_ZERO;
wallet.completeTx(req);
Transaction tx = req.tx;
// Send the tx to sign to the other party offilne. The other party
will give you:
byte[] signatureByThirdParty = ....
ECKey thirdPartyPubKey = ...
// Then complete the partially signed tx
TransactionInput txIn = tx.getInputs().get(0); // This example assumes
just 1 input
Script inputScript = txIn.getScriptSig();
List<ScriptChunk> chunks = inputScript.getChunks();
byte[] program = chunks.get(chunks.size() - 1).data;
Script redeemScript = new Script(program);
Sha256Hash sighash = tx.hashForSignature(0, redeemScript,
Transaction.SigHash.ALL, false);
ECKey.ECDSASignature sig =
ECKey.ECDSASignature.decodeFromDER(signatureByThirdParty));
TransactionSignature txSig = new TransactionSignature(sig,
Transaction.SigHash.ALL, false);
byte[] txSigEncoded = txSig.encodeToBitcoin();
int sigIndex = inputScript.getSigInsertionIndex(sighash, thirdPartyPubKey);
inputScript = ScriptBuilder.updateScriptWithSignature(inputScript,
txSig.encodeToBitcoin(), sigIndex, 1, 1);
txIn.setScriptSig(inputScript);
--
Oscar Guindzberg
On Thu, Dec 29, 2016 at 8:20 AM, Álvaro Castro-Castilla
<[email protected]> wrote:
> I apologize for all this noise.
>
> That last error might be cause by calling broadcast(), instead of
> future().get(). Now the broadcast gets stuck and .get() blocks forever.
>
> I would appreciate any help on this :)
>
> Thank you!!
>
>
>
> On Thursday, December 29, 2016 at 11:51:14 AM UTC+1, Álvaro Castro-Castilla
> wrote:
>>
>> I think one reason was failure to call .broadcast() on the
>> BroadcastTransaction.
>>
>> Now I get 'bad-txns-inputs-duplicate' exception. The only input I add to
>> the transaction (since this part is missing from the documentation) is the
>> only one I get from the getUnspents() list from the wallet.
>>
>> The idea is to send the funds from my wallet to this multisig contract. Is
>> this the correct approach?
>>
>> Thank you!
>>
>>
>>
>> On Thursday, December 29, 2016 at 12:29:05 AM UTC+1, Álvaro
>> Castro-Castilla wrote:
>>>
>>> Hi!
>>>
>>> I'm new to Bitcoinj. I'm trying to figure out the following:
>>> I want to create a wallet from where I can spend only with the input of
>>> 2-of-3 keys (a multisig).
>>>
>>> There are these two different texts in the documentation I've been
>>> reading:
>>>
>>>
>>> https://bitcoinj.github.io/working-with-contracts#creating-multi-signature-outputs
>>> and
>>>
>>> https://bitcoinj.github.io/working-with-the-wallet#marriedmulti-signature-wallets-and-pluggable-signers
>>>
>>> The first is better documented, and I've been giving it a try. I managed
>>> to:
>>> 1) Create a wallet
>>> 2) Send test bitcoins to the wallet (and check that the btc arrives)
>>> 3) Create a multisig contract with the previous transaction as input
>>> (from getUnspents), and the output being what is described in "Working with
>>> contracts"
>>>
>>> However, I can still spend the funds from the wallet, as if there was no
>>> 2-of-3 contract there. What am I missing? Or is it required to do the
>>> "married wallets" approach that is described in less detail in the other
>>> section?
>>>
>>> Thank you!
>
> --
> You received this message because you are subscribed to the Google Groups
> "bitcoinj" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> For more options, visit https://groups.google.com/d/optout.
--
Oscar Guindzberg
--
You received this message because you are subscribed to the Google Groups
"bitcoinj" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
