Java

Encrypt with Chilkat, Decrypt with OpenSSL

See more OpenSSL Examples

Demonstrates how to RSA encrypt a string using Chilkat, and then shows the corresponding OpenSSL command to RSA decrypt. The OpenSSL command to decrypt is as follows:

openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

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;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    CkRsa rsa = new CkRsa();

    //  Note: RSA encryption uses the public key.  
    //  RSA decryption uses the private key.
    //  The reason is that the public key can be freely provided to anybody.  This allows anybody
    //  to send an encrypted message to the private key owner, and only the private key owner 
    //  can decrypt.
    CkPublicKey key = new CkPublicKey();

    //  Load an RSA public key from a PEM file:
    success = key.LoadFromFile("qa_data/pem/VP_Public.pem");
    if (success == false) {
        System.out.println(key.lastErrorText());
        return;
        }

    //  Load the public key into the RSA object.
    success = rsa.UsePublicKey(key);
    if (success == false) {
        System.out.println(rsa.lastErrorText());
        return;
        }

    String strToEncrypt = "00000000;XYZ2-3BHQ-ABCD-MMVV;6MY1-GHJK-9LRR;0";

    //  The LittleEndian property is false by default, but it is set here
    //  anyway to show that LittleEndian byte ordering is required for OpenSSL compatibility.
    rsa.put_LittleEndian(false);

    boolean usePrivateKey = false;
    CkByteData encryptedBytes = new CkByteData();
    success = rsa.EncryptString(strToEncrypt,usePrivateKey,encryptedBytes);
    if (rsa.get_LastMethodSuccess() == false) {
        System.out.println(rsa.lastErrorText());
        return;
        }

    //  The OpenSSL command to decrypt would be this:
    //  openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

    CkFileAccess fac = new CkFileAccess();
    success = fac.WriteEntireFile("qa_output/rsa_encrypted.bin",encryptedBytes);
    if (success == false) {
        System.out.println(fac.lastErrorText());
        return;
        }

    System.out.println("RSA Encryption Succeeded.");
  }
}