Ability To Sign Arbitrary Strings

[claytantor]

When attempting to create an identity JWT for the wallet, which could be used for a backend, there is no way to sign the jwt payload. Using signTransaction returns an empty string.

Given a common JWT payload:

const payload = {
            "pk": ledgerAccount.publicKey,
            "sub": ledgerAccount.address,
            "exp": exp,
            "iat": d.getTime()
        }

and a ledger sign implementation with HID transport...

  // secp256k1 is the default curve used by XRP
  const signPayload = async (
    payload,
    accountIndex = 0, // change that to get details of accounts at different indexes
    keyIndex = 0, 
    ledgerTransport) => 
  {
    let transport = ledgerTransport
    if (!transport) {
      transport = await getLedgerTransport()
      if (!transport) {
        return undefined
      }
    }

    const xrp = new AppXrp(transport)
    console.log("sign payload", payload);

    try {
      const bip32Path = `44'/144'/${accountIndex}'/0/${keyIndex}`;
      const txe = encode(payload);
      const signedPayload = await xrp.signTransaction(bip32Path, txe);
      console.log("signTransaction signedPayload", signedPayload);
      return { signedPayload, bip32Path }
    } 
    catch (error) {
      if (error instanceof Error) {
        console.error(error)
        return
        // handleError(error)
      }
      return undefined
    }  
  }

an empty result is returned for the signed body.

{
    "signedPayload": "",
    "bip32Path": "44'/144'/0'/0/0"
}