org.cryptacular.generator.KeyPairGenerator Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of cryptacular Show documentation
The spectacular complement to the Bouncy Castle crypto API for Java.
There is a newer version: 1.2.7
/* See LICENSE for licensing and NOTICE for copyright. */
package org.cryptacular.generator;

import java.security.InvalidAlgorithmParameterException;
import java.security.KeyPair;
import java.security.SecureRandom;
import org.bouncycastle.jce.spec.ECNamedCurveGenParameterSpec;

/**
 * Static factory that generates various types of asymmetric key pairs.
 *
 * @author  Middleware Services
 */
public final class KeyPairGenerator
{

  /** Private constructor of static factory. */
  private KeyPairGenerator() {}


  /**
   * Generates a DSA key pair.
   *
   * @param  random  Random source required for key generation.
   * @param  bitLength  Desired key size in bits.
   *
   * @return  DSA key pair of desired size.
   */
  public static KeyPair generateDSA(final SecureRandom random, final int bitLength)
  {
    final org.bouncycastle.jcajce.provider.asymmetric.dsa.KeyPairGeneratorSpi generator =
      new org.bouncycastle.jcajce.provider.asymmetric.dsa.KeyPairGeneratorSpi();
    generator.initialize(bitLength, random);
    return generator.generateKeyPair();
  }


  /**
   * Generates a RSA key pair.
   *
   * @param  random  Random source required for key generation.
   * @param  bitLength  Desired key size in bits.
   *
   * @return  RSA key pair of desired size.
   */
  public static KeyPair generateRSA(final SecureRandom random, final int bitLength)
  {
    final org.bouncycastle.jcajce.provider.asymmetric.rsa.KeyPairGeneratorSpi generator =
      new org.bouncycastle.jcajce.provider.asymmetric.rsa.KeyPairGeneratorSpi();
    generator.initialize(bitLength, random);
    return generator.generateKeyPair();
  }


  /**
   * Generates a EC key pair.
   *
   * @param  random  Random source required for key generation.
   * @param  bitLength  Desired key size in bits.
   *
   * @return  EC key pair of desired size.
   */
  public static KeyPair generateEC(final SecureRandom random, final int bitLength)
  {
    final org.bouncycastle.jcajce.provider.asymmetric.ec.KeyPairGeneratorSpi.EC generator =
      new org.bouncycastle.jcajce.provider.asymmetric.ec.KeyPairGeneratorSpi.EC();
    generator.initialize(bitLength, random);
    return generator.generateKeyPair();
  }


  /**
   * Generates a EC key pair.
   *
   * @param  random  Random source required for key generation.
   * @param  namedCurve  Well-known elliptic curve name that includes domain parameters including key size.
   *
   * @return  EC key pair according to named curve.
   */
  public static KeyPair generateEC(final SecureRandom random, final String namedCurve)
  {
    final org.bouncycastle.jcajce.provider.asymmetric.ec.KeyPairGeneratorSpi.EC generator =
      new org.bouncycastle.jcajce.provider.asymmetric.ec.KeyPairGeneratorSpi.EC();
    try {
      generator.initialize(new ECNamedCurveGenParameterSpec(namedCurve), random);
    } catch (InvalidAlgorithmParameterException e) {
      throw new IllegalArgumentException("Invalid EC curve " + namedCurve, e);
    }
    return generator.generateKeyPair();
  }
}