Node crypto sign/verify

signer.js

const crypto = require('crypto')
const fs = require('fs')

function sign(plainText) {
    const sign = crypto.createSign('RSA-SHA512')
    sign.update(Buffer.from(plainText, 'utf8'))
    signature = sign.sign(
        {
            key: fs.readFileSync('./salesforce_private.key', 'utf8'), 
            padding:crypto.constants.RSA_PKCS1_PSS_PADDING
        }
    ).toString('base64')

    return signature;
}

function verify(signature, originMsg) {
    const verify = crypto.createVerify('RSA-SHA512')
    verify.update(Buffer.from(originMsg, 'utf8'))
    verifyRes = verify.verify(
        {
            key: fs.readFileSync('./salesforce_public.key', 'utf8'), 
            padding:crypto.constants.RSA_PKCS1_PSS_PADDING}, 
            Buffer.from(signature, 'base64')
    )

    return verifyRes;
}

const plainText = "reports50";

let s = sign(plainText);
console.log(s);

let results = verify(s, plainText);
console.log(results);