Java

Get RSA Public Key in JWK Format (JSON Web Key)

See more JSON Web Signatures (JWS) Examples

Demonstrates how to get an RSA public key in JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    // Note: This example requires Chilkat v9.5.0.66 or later.

    // Load a PEM file into memory.
    CkStringBuilder sbPem = new CkStringBuilder();
    success = sbPem.LoadFile("qa_data/pem/rsa_public.pem","utf-8");
    if (success != true) {
        System.out.println("Failed to load PEM file.");
        return;
        }

    // Load the PEM into a public key object.
    CkPublicKey pubKey = new CkPublicKey();
    success = pubKey.LoadFromString(sbPem.getAsString());
    if (success != true) {
        System.out.println(pubKey.lastErrorText());
        return;
        }

    // Get the public key in JWK format:
    String jwk = pubKey.getJwk();

    // The GetJwk method will return the JWK in the most compact JSON format possible,
    // as a single line with no extra whitespace.  To get a more human-readable JWK (for this example),
    // load into a Chilkat JSON object and emit non-compact:

    CkJsonObject json = new CkJsonObject();
    json.Load(jwk);
    json.put_EmitCompact(false);
    System.out.println("RSA Public Key in JWK format:");
    System.out.println(json.emit());

    // Sample output:
    // { 
    //   "kty": "RSA",
    //   "n": "33TqqLR3eeUmDtHS89qF3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA04DDnEFGAf-kDQiNSe2ZtqC7bnIc8-KSG_qOGQIVaay4Ucr6ovDkykO5Hxn7OU7sJp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwFwnxCsU5-UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUEf0YN3_Q0auBkdbDR_ES2PbgKTJdkjc_rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1WSw",
    //   "e": "AQAB"
    // }

    // Additional information can be added like this:
    json.AppendString("use","enc");
    json.AppendString("kid","123ABC");

    // Now examine the JSON:
    System.out.println(json.emit());

    // { 
    //   "kty": "RSA",
    //   "n": "33TqqLR3eeUmDtHS89qF3p4MP7Wfqt2Zjj3lZjLjjCGDvwr9cJNlNDiuKboODgUiT4ZdPWbOiMAfDcDzlOxA04DDnEFGAf-kDQiNSe2ZtqC7bnIc8-KSG_qOGQIVaay4Ucr6ovDkykO5Hxn7OU7sJp9TP9H0JH8zMQA6YzijYH9LsupTerrY3U6zyihVEDXXOv08vBHk50BMFJbE9iwFwnxCsU5-UZUZYw87Uu0n4LPFS9BT8tUIvAfnRXIEWCha3KbFWmdZQZlyrFw0buUEf0YN3_Q0auBkdbDR_ES2PbgKTJdkjc_rEeM0TxvOUf7HuUNOhrtAVEN1D5uuxE1WSw",
    //   "e": "AQAB",
    //   "use": "enc",
    //   "kid": "123ABC"
    // }
  }
}