Convert AWS IAM credentials to AWS SMTP credentials

.js

const crypto = require("crypto");

const secretAccessKey = ""; // AWS_ACCESS_KEY_SECRET
const regionName = "us-east-1";

// Assuming you've already set up your SES Policy on your IAM User:
// {
//   "Version": "2012-10-17",
//   "Statement": [
//     {
//       "Effect":"Allow",
//       "Action":["ses:SendEmail", "ses:SendRawEmail"],
//       "Resource":"*"
//     }
//   ]
// }

const date = "11111111";
const service = "ses";
const terminal = "aws4_request";
const message = "SendRawEmail";
const versionInBytes = [4]; // Signature Version 4

const kDate = sign(date, "AWS4" + secretAccessKey);
const kRegion = sign(regionName, kDate);
const kService = sign(service, kRegion);
const kTerminal = sign(terminal, kService);
const kMessage = sign(message, kTerminal);

const signatureAndVersion = Buffer.from([...versionInBytes, ...kMessage]);
const smtpPassword = signatureAndVersion.toString("base64");

console.log(smtpPassword);

function sign(string, key) {
  const hmac = crypto.createHmac("sha256", key);
  hmac.update(string);
  return hmac.digest();
}