org.bouncycastle.jcajce.provider.symmetric.TLSKDF 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.jcajce.provider.symmetric;

import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;

import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.crypto.Mac;
import org.bouncycastle.crypto.digests.SHA256Digest;
import org.bouncycastle.crypto.digests.SHA384Digest;
import org.bouncycastle.crypto.digests.SHA512Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.util.DigestFactory;
import org.bouncycastle.jcajce.provider.config.ConfigurableProvider;
import org.bouncycastle.jcajce.provider.symmetric.util.BaseSecretKeyFactory;
import org.bouncycastle.jcajce.provider.util.AlgorithmProvider;
import org.bouncycastle.jcajce.spec.TLSKeyMaterialSpec;
import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.Strings;

public class TLSKDF
{
    public static class TLSKeyMaterialFactory
        extends BaseSecretKeyFactory
    {
        protected TLSKeyMaterialFactory(String algName)
        {
            super(algName, null);
        }
    }

    public static final class TLS10
        extends TLSKeyMaterialFactory
    {
        public TLS10()
        {
            super("TLS10KDF");
        }

        protected SecretKey engineGenerateSecret(
            KeySpec keySpec)
        throws InvalidKeySpecException
        {
            if (keySpec instanceof TLSKeyMaterialSpec)
            {
                return new SecretKeySpec(PRF_legacy((TLSKeyMaterialSpec)keySpec), algName);
            }

            throw new InvalidKeySpecException("Invalid KeySpec");
        }
    }

    public static final class TLS11
        extends TLSKeyMaterialFactory
    {
        public TLS11()
        {
            super("TLS11KDF");
        }

        protected SecretKey engineGenerateSecret(
            KeySpec keySpec)
        throws InvalidKeySpecException
        {
            if (keySpec instanceof TLSKeyMaterialSpec)
            {
                return new SecretKeySpec(PRF_legacy((TLSKeyMaterialSpec)keySpec), algName);
            }

            throw new InvalidKeySpecException("Invalid KeySpec");
        }
    }

    private static byte[] PRF_legacy(TLSKeyMaterialSpec parameters)
    {
        Mac md5Hmac = new HMac(DigestFactory.createMD5());
        Mac sha1HMac = new HMac(DigestFactory.createSHA1());

        byte[] label = Strings.toByteArray(parameters.getLabel());
        byte[] labelSeed = Arrays.concatenate(label, parameters.getSeed());
        byte[] secret = parameters.getSecret();

        int s_half = (secret.length + 1) / 2;
        byte[] s1 = new byte[s_half];
        byte[] s2 = new byte[s_half];
        System.arraycopy(secret, 0, s1, 0, s_half);
        System.arraycopy(secret, secret.length - s_half, s2, 0, s_half);

        int size = parameters.getLength();
        byte[] b1 = new byte[size];
        byte[] b2 = new byte[size];

        hmac_hash(md5Hmac, s1, labelSeed, b1);
        hmac_hash(sha1HMac, s2, labelSeed, b2);

        for (int i = 0; i < size; i++)
        {
            b1[i] ^= b2[i];
        }
        return b1;
    }

    public static class TLS12
        extends TLSKeyMaterialFactory
    {
        private final Mac prf;

        protected TLS12(String algName, Mac prf)
        {
            super(algName);
            this.prf = prf;
        }

        protected SecretKey engineGenerateSecret(
            KeySpec keySpec)
        throws InvalidKeySpecException
        {
            if (keySpec instanceof TLSKeyMaterialSpec)
            {
                return new SecretKeySpec(PRF((TLSKeyMaterialSpec)keySpec, prf), algName);
            }

            throw new InvalidKeySpecException("Invalid KeySpec");
        }

        private byte[] PRF(TLSKeyMaterialSpec parameters, Mac prf)
        {
            byte[] label = Strings.toByteArray(parameters.getLabel());
            byte[] labelSeed = Arrays.concatenate(label, parameters.getSeed());
            byte[] secret = parameters.getSecret();

            byte[] buf = new byte[parameters.getLength()];

            hmac_hash(prf, secret, labelSeed, buf);

            return buf;
        }
    }

    public static final class TLS12withSHA256
        extends TLS12
    {
        public TLS12withSHA256()
        {
            super("TLS12withSHA256KDF", new HMac(SHA256Digest.newInstance()));
        }
    }

    public static final class TLS12withSHA384
        extends TLS12
    {
        public TLS12withSHA384()
        {
            super("TLS12withSHA384KDF", new HMac(new SHA384Digest()));
        }
    }

    public static final class TLS12withSHA512
        extends TLS12
    {
        public TLS12withSHA512()
        {
            super("TLS12withSHA512KDF", new HMac(new SHA512Digest()));
        }
    }

    private static void hmac_hash(Mac mac, byte[] secret, byte[] seed, byte[] out)
    {
        mac.init(new KeyParameter(secret));
        byte[] a = seed;
        int size = mac.getMacSize();
        int iterations = (out.length + size - 1) / size;
        byte[] buf = new byte[mac.getMacSize()];
        byte[] buf2 = new byte[mac.getMacSize()];
        for (int i = 0; i < iterations; i++)
        {
            mac.update(a, 0, a.length);
            mac.doFinal(buf, 0);
            a = buf;
            mac.update(a, 0, a.length);
            mac.update(seed, 0, seed.length);
            mac.doFinal(buf2, 0);
            System.arraycopy(buf2, 0, out, (size * i), Math.min(size, out.length - (size * i)));
        }
    }

    public static class Mappings
        extends AlgorithmProvider
    {
        private static final String PREFIX = TLSKDF.class.getName();

        public Mappings()
        {
        }

        public void configure(ConfigurableProvider provider)
        {
            provider.addAlgorithm("SecretKeyFactory.TLS10KDF", PREFIX + "$TLS10");
            provider.addAlgorithm("SecretKeyFactory.TLS11KDF", PREFIX + "$TLS11");
            provider.addAlgorithm("SecretKeyFactory.TLS12WITHSHA256KDF", PREFIX + "$TLS12withSHA256");
            provider.addAlgorithm("SecretKeyFactory.TLS12WITHSHA384KDF", PREFIX + "$TLS12withSHA384");
            provider.addAlgorithm("SecretKeyFactory.TLS12WITHSHA512KDF", PREFIX + "$TLS12withSHA512");
        }
    }
}