MultiChain Developer Q&A - Recent questions tagged signing

signing message gets different result from bitcoin core

Wed, 06 Nov 2019 23:04:45 +0000

Dear multichain,

I need to understand better the sign message algorithm.
I have the following scenario in a bitcoin-compatible Multichain setting:

address: 1PYdSSwsXgJe1MGMzkeXCdshxjMfDP64wi
pvkey: L4PW5JZVpLkNmCKNUSjji3Fpd29s3ci8onwyhvGody4e633Th6vT

signmessage "1PYdSSwsXgJe1MGMzkeXCdshxjMfDP64wi" "message_to_sign"

signature: IC8PmdB4gwxfszrCS0JWPgq/sKt9F+FXtfnZl0eMExNULfcF7rXX7LnGczQ3VaK5pBJQsbn/MGSH/GII+/99zUQ=

I can check the result

verifymessage "1PYdSSwsXgJe1MGMzkeXCdshxjMfDP64wi" "IC8PmdB4gwxfszrCS0JWPgq/sKt9F+FXtfnZl0eMExNULfcF7rXX7LnGczQ3VaK5pBJQsbn/MGSH/GII+/99zUQ=" "message_to_sign"

true

Everything works fine but using bitcoin core I get a different result (I used this online tool https://reinproject.org/bitcoin-signature-tool/#sign) :

-----BEGIN BITCOIN SIGNED MESSAGE-----
message_to_sign
-----BEGIN SIGNATURE-----
1PYdSSwsXgJe1MGMzkeXCdshxjMfDP64wi
IDvDfON3ikxMOXOoOuOl50ZZ517CWqBDcniGMqBH187CVwS3fxXj8WzK13n1QDbov33vyBhs5To8TqdjqWsjxVs=
-----END BITCOIN SIGNED MESSAGE-----

Could you help me understanding this point?

I have a basic send transaction I need to sign

Tue, 20 Aug 2019 19:21:29 +0000

When using send to move an asset between addresses, is it possible to sign the successful transaction? If so, is there an example? Which parameters do I need?

Block-signing key off-node

Fri, 07 Sep 2018 13:30:26 +0000

A high level of security is essential for private keys. Fortunately, it is possible to sign transactions with keys that are stored on a HSM. However, is the same also possible for signing blocks, as part of the multichain 'mining' process?

Manually signing a transaction with multiple inputs

Fri, 31 Aug 2018 04:59:51 +0000

Hi,

After referencing the discussion thread from https://www.multichain.com/qa/1923/manually-sign-a-raw-transaction, I've been using daanporon's method for signing multichain transactions using javascript, as provided here: https://gist.github.com/daanporon/28087f042fb83507f5dc9389119a0508

However, his method only works for transactions that have a single input, as he is only signing transaction.vin[0]. So I encountered a problem when trying to sign a transaction with 2 inputs.

I tried to modify his implementation to sign all the inputs. I assumed it's similar to bitcoin, so I used the answer from this thread as reference: https://bitcoin.stackexchange.com/questions/41209/how-to-sign-a-transaction-with-multiple-inputs

Basically, my algorithm is:

For each vin

Remove the scriptSig from all other vins
Set this vin.scriptSig = OP_DUP+OP_HASH160+pubkeyhash+OP_EQUAL_VERIFY+OP_CHECKSIG (to mimic the output of the prevtx; this is what daan's code already does)
Generate the hash from this new version of the transaction
Sign the hash and store the signature in a separate array (so that it doesnt get lost when the next vin is processed)

After all vins are processed, I copy the generated signatures from the separate array in the last step to their respective vins.

However, when I try this approach with my transaction which has two inputs, the transaction is still invalid (raises ConnectInputs error when sending it). I compared it to the equivalent output of signrawtransaction using the multichain API, and found that the scriptSig of vin #0 is wrong, but the scriptSig of vin#1 is correct. Both vins reference prevtx that are sent to the same address and I'm signing them using the same private key.

Given that I'm getting one of the signatures right, I'm assuming I'm kind of on the right track, but maybe I'm just missing a step or two somewhere?

Would anyone be able to advice if the approach I'm using is incorrect, or how else I can update it? (Actually, I'm hoping daanporon would be able to comment as well if he sees this - or anyone who can help)

Windows executable signing

Tue, 26 Sep 2017 08:34:08 +0000

Would it be possible for the next release to request that all windows executables are signed?

I required them to be signed else i cannot run them from within another console application. I have an application that monitors applications and restarts them in case the server crashes or a particular application crashes for an unknown reason.

I cannot restart/start multichaind in this instance, i have to do it manually at the moment , i am getting untrusted publisher messages when i try to automate this process.

Example of external signing of a transaction

Mon, 03 Oct 2016 10:23:27 +0000

Hi Multichain Team,

Do we have an example which shows external signing of a transaction before passing to sendrawtransaction api?

I have a B2C scenario where I am thinking of having multiple addresses at one node for different customers but in watch only mode. And keeping the the private key of the customer on the app side which will externally sign the transaction and pass it to node.