JSEncypt to nodejs crypto and back

test.js

const JSEncrypt = require('node-jsencrypt');
const crypto = require('crypto');

const text = ' Some text ÜÄ';

const privateKey = `
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
`.trim();

const publicKey = `
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDlOJu6TyygqxfWT7eLtGDwajtN
FOb9I5XRb6khyfD1Yt3YiCgQWMNW649887VGJiGr/L5i2osbl8C9+WJTeucF+S76
xFxdU6jE0NQ+Z+zEdhUTooNRaY5nZiu5PgDB0ED/ZKBUSLKL7eibMxZtMlUDHjm4
gwQco1KRMDSmXSMkDwIDAQAB
-----END PUBLIC KEY-----
`.trim();

const jsEncryptEncrypt = (message) => {
  const crypt1 = new JSEncrypt();
  crypt1.setKey(publicKey);
  const encrypted = crypt1.encrypt(message);
  return encrypted;
};

const jsEncryptDecrypt = (message) => {
  const crypt2 = new JSEncrypt();
  crypt2.setKey(privateKey);
  const decrypted = crypt2.decrypt(message);
  return decrypted;
};

const privateKeyObj = crypto.createPrivateKey(privateKey);
const publicKeyObj = crypto.createPublicKey(publicKey);

const pad = (buf, length) => {
  const missingLength = length - buf.length;
  const randomNumber = 0xff;
  const ps = Buffer.allocUnsafe(missingLength - 3).fill(randomNumber);
  return Buffer.concat([Buffer.from([0x00, 0x02]), ps, Buffer.from([0x00]), buf]);
};

const unpad = (buf) => {
  const prefixLength = 2;
  const paddingEndIndex = buf.indexOf(0, prefixLength - 1);
  return buf.slice(paddingEndIndex + 1);
};

const nodejsEncrypt = (message) => {
  const paddedMessage = pad(Buffer.from(message, 'utf-8'), 128);
  const result = crypto.publicEncrypt(
    { key: publicKeyObj, padding: crypto.constants.RSA_NO_PADDING },
    paddedMessage,
  );
  return result.toString('base64');
};

const nodejsDecrypt = (message) => {
  const result = crypto.privateDecrypt(
    { key: privateKeyObj, padding: crypto.constants.RSA_NO_PADDING },
    Buffer.from(message, 'base64'),
  );

  return unpad(result).toString('utf-8');
};

const TEST_CASES = [
  [jsEncryptEncrypt, jsEncryptDecrypt, 'jsencrypt-jsencrypt'],
  [nodejsEncrypt, jsEncryptDecrypt, 'nodejs-jsencrypt'],
  [jsEncryptEncrypt, nodejsDecrypt, 'jsencrypt-nodejs'],
  [nodejsEncrypt, nodejsDecrypt, 'nodejs-nodejs'],
];

for (const [encrypt, decrypt, name] of TEST_CASES) {
  console.log();
  console.log('<<<<<', name, '>>>>>');
  const encrypted = encrypt(text);
  console.log('encrypted', encrypted);
  const decrypted = decrypt(encrypted);
  console.log('decrypted', decrypted);

  if (text !== decrypted) {
    console.log('FAIL');
  } else {
    console.log('PASS');
  }
}