hayeah / qtumsign

qtum message signing example in JS

qtum message signing in qtum

This example produces the same signed message as that returned by the signmessage command.

First, import the keypair we'll be using for the example:

# pubkey: qUbxboqjBRp96j3La8D1RYkyqx5uQbJPoW
qcli importprivkey cMbgxCJrTYUqgcmiC1berh5DFrtY1KeU4PXZ6NZxgenniF1mXCRk

Using the cli to sign "hello world":

qcli signmessage qUbxboqjBRp96j3La8D1RYkyqx5uQbJPoW "hello world"

HzWV5Pkukar3MRJ7Q6zuwISJSISEIYAGYLf4rOULZopLTtO61ak/HBaFxQlY7+QP1Wa4r9sLLvZ5ATJ3UGOAzh8=

And to verify it:

qcli verifymessage qUbxboqjBRp96j3La8D1RYkyqx5uQbJPoW \
  "HzWV5Pkukar3MRJ7Q6zuwISJSISEIYAGYLf4rOULZopLTtO61ak/HBaFxQlY7+QP1Wa4r9sLLvZ5ATJ3UGOAzh8=" \
  "hello world"

true

Running index.js should yield the same signature bytes:

msg hash: 33fd9f69e51a562f5457e71dcf14bd723cdc9134bae6cdef5891baa8386ebb5c
sig base64: HzWV5Pkukar3MRJ7Q6zuwISJSISEIYAGYLf4rOULZopLTtO61ak/HBaFxQlY7+QP1Wa4r9sLLvZ5ATJ3UGOAzh8=
sig hex: 1f3595e4f92e91aaf731127b43aceec0848948848421800660b7f8ace50b668a4b4ed3bad5a93f1c1685c50958efe40fd566b8afdb0b2ef679013277506380ce1f

The signature is actually consisted of three parts:

V: 1f
R: 3595e4f92e91aaf731127b43aceec0848948848421800660b7f8ace50b668a4b
S: 4ed3bad5a93f1c1685c50958efe40fd566b8afdb0b2ef679013277506380ce1f

Where V is the version string.

For example how the signer is recovered:

Solidity Contract

JS Calling Solidity Contract