/*

 * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package com.oracle.security.ucrypto;

import java.util.Set;

import java.util.Arrays;

import java.util.concurrent.ConcurrentSkipListSet;

import java.lang.ref.*;

import java.math.BigInteger;

import java.security.*;

import java.security.interfaces.*;

import java.security.spec.*;

/**

 * Wrapper class for native keys needed for using ucrypto APIs.

 * This class currently supports native RSA private/public keys.

 *

 */

abstract class NativeKey implements Key {

    private static final long serialVersionUID = 6812507588904302830L;

    private final int numComponents;

    NativeKey(int numComponents) {

        this.numComponents = numComponents;

    }

    abstract long value();

    int length() {

        return numComponents;

    }

    public String getAlgorithm() { return "RSA"; }

    public String getFormat() { return "RAW"; }

    public byte[] getEncoded() {

        // not used; so not generated

        return null;

    }

    private native static void nativeFree(long id, int numComponents);

    static byte[] getMagnitude(BigInteger bi) {

        byte[] b = bi.toByteArray();

        if ((b.length > 1) && (b[0] == 0)) {

            int n = b.length - 1;

            byte[] newarray = new byte[n];

            System.arraycopy(b, 1, newarray, 0, n);

            b = newarray;

        }

        return b;

    }

    static final class RSAPrivate extends NativeKey implements RSAPrivateKey {

        private static final long serialVersionUID = 1622705588904302831L;

        private final RSAPrivateKeySpec keySpec;

        private final long keyId;

        RSAPrivate(KeySpec keySpec) throws InvalidKeySpecException {

            super(2);

            long pKey = 0L;

            if (keySpec instanceof RSAPrivateKeySpec) {

                RSAPrivateKeySpec ks = (RSAPrivateKeySpec) keySpec;

                BigInteger mod = ks.getModulus();

                BigInteger privateExp =  ks.getPrivateExponent();

                pKey = nativeInit(NativeKey.getMagnitude(mod),

                                  NativeKey.getMagnitude(privateExp));

            } else {

                throw new InvalidKeySpecException("Only supports RSAPrivateKeySpec." +

                    " Received: " + keySpec.getClass().getName());

            }

            if (pKey == 0L) {

                throw new UcryptoException("Error constructing RSA PrivateKey");

            }

            // track native resource clean up

            new KeyRef(this, pKey);

            this.keySpec = (RSAPrivateKeySpec) keySpec;

            this.keyId = pKey;

        }

        long value() { return keyId; }

        public BigInteger getModulus() { return keySpec.getModulus(); };

        public BigInteger getPrivateExponent() { return keySpec.getPrivateExponent(); };

        private native static long nativeInit(byte[] mod, byte[] privExp);

    }

    static final class RSAPrivateCrt extends NativeKey implements RSAPrivateCrtKey {

        private static final long serialVersionUID = 6812507588904302831L;

        private final RSAPrivateCrtKeySpec keySpec;

        private final long keyId;

        RSAPrivateCrt(KeySpec keySpec) throws InvalidKeySpecException {

            super(8);

            long pKey = 0L;

            if (keySpec instanceof RSAPrivateCrtKeySpec) {

                RSAPrivateCrtKeySpec ks = (RSAPrivateCrtKeySpec) keySpec;

                BigInteger mod = ks.getModulus();

                BigInteger publicExp =  ks.getPublicExponent();

                BigInteger privateExp =  ks.getPrivateExponent();

                BigInteger primeP = ks.getPrimeP();

                BigInteger primeQ = ks.getPrimeQ();

                BigInteger primeExpP = ks.getPrimeExponentP();

                BigInteger primeExpQ = ks.getPrimeExponentQ();

                BigInteger crtCoeff = ks.getCrtCoefficient();

                pKey = nativeInit(NativeKey.getMagnitude(mod),

                                  NativeKey.getMagnitude(publicExp),

                                  NativeKey.getMagnitude(privateExp),

                                  NativeKey.getMagnitude(primeP),

                                  NativeKey.getMagnitude(primeQ),

                                  NativeKey.getMagnitude(primeExpP),

                                  NativeKey.getMagnitude(primeExpQ),

                                  NativeKey.getMagnitude(crtCoeff));

            } else {

                throw new InvalidKeySpecException("Only supports RSAPrivateCrtKeySpec."

                    + " Received: " + keySpec.getClass().getName());

            }

            if (pKey == 0L) {

                throw new UcryptoException("Error constructing RSA PrivateCrtKey");

            }

            // track native resource clean up

            new KeyRef(this, pKey);

            this.keySpec = (RSAPrivateCrtKeySpec) keySpec;

            this.keyId = pKey;

        }

        long value() { return keyId; }

        public BigInteger getModulus() { return keySpec.getModulus(); };

        public BigInteger getPublicExponent() { return keySpec.getPublicExponent(); };

        public BigInteger getPrivateExponent() { return keySpec.getPrivateExponent(); };

        public BigInteger getPrimeP() { return keySpec.getPrimeP(); };

        public BigInteger getPrimeQ() { return keySpec.getPrimeQ(); };

        public BigInteger getPrimeExponentP() { return keySpec.getPrimeExponentP(); };

        public BigInteger getPrimeExponentQ() { return keySpec.getPrimeExponentQ(); };

        public BigInteger getCrtCoefficient() { return keySpec.getCrtCoefficient(); };

        private native static long nativeInit(byte[] mod, byte[] pubExp, byte[] privExp,

                                      byte[] p, byte[] q,

                                      byte[] expP, byte[] expQ, byte[] crtCoeff);

    }

    static final class RSAPublic extends NativeKey implements RSAPublicKey {

        private static final long serialVersionUID = 6812507588904302832L;

        private final RSAPublicKeySpec keySpec;

        private final long keyId;

        RSAPublic(KeySpec keySpec) throws InvalidKeySpecException {

            super(2);

            long pKey = 0L;

            if (keySpec instanceof RSAPublicKeySpec) {

                RSAPublicKeySpec ks = (RSAPublicKeySpec) keySpec;

                BigInteger mod = ks.getModulus();

                BigInteger publicExp = ks.getPublicExponent();

                pKey = nativeInit(NativeKey.getMagnitude(mod),

                                  NativeKey.getMagnitude(publicExp));

            } else {

                throw new InvalidKeySpecException("Only supports RSAPublicKeySpec." +

                    " Received: " + keySpec.getClass().getName());

            }

            if (pKey == 0L) {

                throw new UcryptoException("Error constructing RSA PublicKey");

            }

            // track native resource clean up

            new KeyRef(this, pKey);

            this.keySpec = (RSAPublicKeySpec) keySpec;

            this.keyId = pKey;

        }

        long value() { return keyId; }

        public BigInteger getModulus() { return keySpec.getModulus(); };

        public BigInteger getPublicExponent() { return keySpec.getPublicExponent(); };

        private native static long nativeInit(byte[] mod, byte[] pubExp);

    }

    // internal class for native resource cleanup

    private static class KeyRef extends PhantomReference<NativeKey>

        implements Comparable<KeyRef> {

        private static ReferenceQueue<NativeKey> refQueue =

            new ReferenceQueue<NativeKey>();

        // Needed to keep these references from being GC'ed until when their

        // referents are GC'ed so we can do post-mortem processing

        private static Set<KeyRef> refList =

            new ConcurrentSkipListSet<KeyRef>();

        private final long id;

        private final int length;

        private static void drainRefQueueBounded() {

            while (true) {

                KeyRef next = (KeyRef) refQueue.poll();

                if (next == null) break;

                next.dispose();

            }

        }

        KeyRef(NativeKey nk, long id) {

            super(nk, refQueue);

            this.id = id;

            this.length = nk.length();

            refList.add(this);

            UcryptoProvider.debug("Resource: track NativeKey " + this.id);

            drainRefQueueBounded();

        }

        public int compareTo(KeyRef other) {

            if (this.id == other.id) {

                return 0;

            } else {

                return (this.id < other.id) ? -1 : 1;

            }

        }

        void dispose() {

            refList.remove(this);

            UcryptoProvider.debug("Resource: free NativeKey " + this.id);

            try {

                NativeKey.nativeFree(id, length);

            } finally {

                this.clear();

            }

        }

    }

}