Evmos keplr message verifier

Verify messages signed with signArbitrary using evmos addresses

Installation

yarn add @hanchon/evmos-keplr-message-verifier

Usage

Sign a message using keplr

const chainId = 'evmos_9001-2'
const message = 'something'
const address = 'evmos13f4uur7qw3yd87v3ujdle0xtzcjnskywdrnjhp'
const signature = await window.keplr.signArbitrary(
    chainId,
    address,
    message,
)

Verify the message

// Address, message and signature are the same as the previous step
const pubKey = 'A/o4Mu4lzmuWORZPfLfDJIhuFJu2Dwq/ytZBAM1mXNGs'
const validSignature = verifyKeplrSignature(address, pubKey, message, signature)
// if validSignature === true, the message was signed by that address

Note: the pubKey of the current connected address can be obtained using:

await window.keplr.enable(chainId)
const offlineSigner = window.getOfflineSigner(chainId)
const wallets = await offlineSigner.getAccounts()
const pubKey = Buffer.from(wallets[0].pubkey).toString('base64')

Why?

Using keplr to sign with signArbitraty using Evmos it will sign the message using the keccak_256 hashing algorithm, but when validating the message it's using the cosmos' default so it'll return always invalid signer.

Known issues

The serializer is breaking for even length string and it's failing to validate the signer