Sample code for 30+ languages & platforms
React Native Requires Chilkat v11.0.0+

Generate RSA Key and Export to PKCS1 / PKCS8

See more RSA Examples

_LANGUAGE_ example code showing how to generate an RSA public/private key and save to PKCS1 and PKCS8 format files. In a PKCS1 or PKCS8 formatted file, the key is stored in binary ASN.1 format (and ASN.1 is itself written according to DER -- Distinguished Encoding Rules). A PEM file simply contains the binary ASN.1 base64 encoded and delimited by BEGIN/END lines. PKCS1 format files are never encrypted. PKCS8 can be encrypted or unencrypted. Public keys are never encrypted (there is no need). Private keys *should* always be encrypted - unless perhaps the unencrypted private key is obtained and itself stored in some sort of secure place.

Chilkat React Native Downloads

React Native
import { PrivateKey, PublicKey, Rsa } from '@chilkat/react-native'

function chilkatExample() {
  // This example assumes the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  const rsa = new Rsa();

  // Generate a 2048-bit key.  Chilkat RSA supports
  // key sizes ranging from 512 bits to 8192 bits.
  const privKey = new PrivateKey();
  try {
    rsa.genKey(2048, privKey);
  } catch {
    console.log(rsa.lastErrorText);
    return;
  }

  // Get the public key
  const pubKey = new PublicKey();
  privKey.toPublicKey(pubKey);

  // Get the public key as a PKCS8 PEM string
  const pubKeyPem = pubKey.getPem(false);
  console.log(pubKeyPem);

  // Get the public key in PKCS8 format, in a Base64 encoded string.
  const pubKeyPkcs8Base64 = pubKey.getEncoded(false, 'base64');
  console.log(pubKeyPkcs8Base64);

  // Get the public key in PKCS1 format, in a Base64 encoded string.
  const pubKeyPkcs1Base64 = pubKey.getEncoded(true, 'base64');
  console.log(pubKeyPkcs1Base64);

  // Get the private key in a PKCS8 PEM string.
  const privKeyPem = privKey.getPkcs8Pem();
  console.log(privKeyPem);

  // Get the private key in a PKCS8 encrypted PEM string.
  const privKeyEncPem = privKey.getPkcs8EncryptedPem('myPassword');
  console.log(privKeyEncPem);

  // Get the private key in PKCS1 Base64 format
  const privKeyPkcs1Base64 = privKey.getPkcs1ENC('base64');
  console.log(privKeyPkcs1Base64);

  // Get the private key in PKCS8 Base64 format
  const privKeyPkcs8Base64 = privKey.getPkcs8ENC('base64');
  console.log(privKeyPkcs8Base64);

  // Save to PKCS1 / PKCS8 / PEM files...

  // Save the public key to PKCS8 binary DER
  pubKey.saveDerFile(false, 'pubKey_pkcs8.der');

  // Save the public key to PKCS1 binary DER
  pubKey.saveDerFile(true, 'pubKey_pkcs1.der');

  // Save the private key to unencrypted binary PKCS1 DER.
  // Note: PKCS1 is never found in an encrypted format. 
  privKey.savePkcs1File('privKey_pkcs1.der');

  // Save the private key to unencrypted binary PKCS8
  privKey.savePkcs8File('privKey_pkcs8.der');

  // Save the private key to encrypted binary PKCS8
  privKey.savePkcs8EncryptedFile('myPassword', 'privKey_enc_pkcs8.der');

  // Save the private key to unencrypted PKCS8 PEM
  privKey.savePkcs8PemFile('privKey.pem');

  // Save the private key to encrypted PKCS8 PEM
  privKey.savePkcs8EncryptedPemFile('myPassword', 'privKey_enc.pem');
}