org.bouncycastle.pqc.crypto.cmce.CMCEKEMGenerator Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of bcprov-ext-debug-jdk18on Show documentation

The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for Java 1.8 and later with debug enabled.

The newest version!

package org.bouncycastle.pqc.crypto.cmce;

import java.security.SecureRandom;

import org.bouncycastle.crypto.EncapsulatedSecretGenerator;
import org.bouncycastle.crypto.SecretWithEncapsulation;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.pqc.crypto.util.SecretWithEncapsulationImpl;

public class CMCEKEMGenerator
    implements EncapsulatedSecretGenerator
{
    // the source of randomness
    private final SecureRandom sr;

    public CMCEKEMGenerator(SecureRandom random)
    {
        this.sr = random;
    }

    public SecretWithEncapsulation generateEncapsulated(AsymmetricKeyParameter recipientKey)
    {
        CMCEPublicKeyParameters key = (CMCEPublicKeyParameters)recipientKey;
        CMCEEngine engine = key.getParameters().getEngine();

        return generateEncapsulated(recipientKey, engine.getDefaultSessionKeySize());
    }

    public SecretWithEncapsulation generateEncapsulated(AsymmetricKeyParameter recipientKey, int sessionKeySizeInBits)
    {
        CMCEPublicKeyParameters key = (CMCEPublicKeyParameters)recipientKey;
        CMCEEngine engine = key.getParameters().getEngine();
        byte[] cipher_text = new byte[engine.getCipherTextSize()];
        byte[] sessionKey = new byte[sessionKeySizeInBits / 8];     // document as 32 - l/8  - Section 2.5.2
        engine.kem_enc(cipher_text, sessionKey, key.getPublicKey(), sr);
        return new SecretWithEncapsulationImpl(sessionKey, cipher_text);
    }
}