(Java) RSA Encrypt RSA/ECB/OAEPWithSHA1AndMGF1Padding

Demonstrates how to RSA encrypt using RSA/ECB/OAEPWithSHA1AndMGF1Padding. Also demonstrates RSA/ECB/OAEPWithSHA-256AndMGF1Padding. Both of these terms are from Java's JCE. Note: In this context, "ECB" doesn't actually mean anything. It's a symmetric cipher mode that doesn't apply (or make sense) in this context.

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

    CkRsa rsa = new CkRsa();

    // First load a public key object with a public key.
    // In this case, we'll load it from a file.
    CkPublicKey pubkey = new CkPublicKey();
    boolean success = pubkey.LoadFromFile("qa_data/pem/rsa_public.pem");
    if (success != true) {
        System.out.println(pubkey.lastErrorText());
        return;
        }

    // RSA encryption is limited to small amounts of data. The limit
    // is typically a few hundred bytes and is based on the key size and
    // padding (OAEP vs. PKCS1_5).  RSA encryption is typically used for
    // encrypting hashes or symmetric (bulk encryption algorithm) secret keys.
    String plainText = "Time is an illusion. Lunchtime doubly so.";

    // Import the public key to be used for encrypting.
    success = rsa.ImportPublicKeyObj(pubkey);

    // To get OAEP padding, set the OaepPadding property:
    rsa.put_OaepPadding(true);

    // To use SHA1 or SHA-256, set the OaepHash property
    rsa.put_OaepHash("sha256");
    // for SHA1 --
    rsa.put_OaepHash("sha1");

    // Indicate we'll want hex output
    rsa.put_EncodingMode("hex");

    // Encrypt..
    boolean usePrivateKey = false;
    String encryptedStr = rsa.encryptStringENC(plainText,usePrivateKey);
    System.out.println(encryptedStr);

    // -------------------------------------------------
    // Now decrypt with the matching private key.
    CkRsa rsa2 = new CkRsa();

    CkPrivateKey privKey = new CkPrivateKey();
    success = privKey.LoadEncryptedPem("qa_data/pem/rsa_passwd.pem","passwd");
    if (success != true) {
        System.out.println(privKey.lastErrorText());
        return;
        }

    success = rsa2.ImportPrivateKeyObj(privKey);

    // Make sure we have the same settings used for encryption.
    rsa2.put_OaepPadding(true);
    rsa2.put_EncodingMode("hex");
    rsa2.put_OaepHash("sha1");

    String originalStr = rsa2.decryptStringENC(encryptedStr,true);

    System.out.println(originalStr);
  }
}