/*

 * Copyright (c) 2018, 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.

 *

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.security.*;

import java.security.spec.*;

import java.security.interfaces.*;

import java.util.ArrayList;

import java.util.List;

/*

 * @test

 * @bug 8146293

 * @summary Known Answer Tests based on NIST 186-3 at:

 * @compile SigRecord.java

 * @run main/othervm TestSigGenPSS

 */

public class TestSigGenPSS {

    private static final String[] testFiles = {

        "SigGenPSS_186-3.txt", "SigGenPSS_186-3_TruncatedSHAs.txt"

    };

    static final class MyKnownRandomSrc extends SecureRandom {

        final byte[] srcBytes;

        int numBytes;

        MyKnownRandomSrc(String srcString) {

            this.srcBytes = SigRecord.toByteArray(srcString);

            this.numBytes = this.srcBytes.length;

        }

        @Override

        public void nextBytes(byte[] bytes) {

            if (bytes.length > numBytes) {

                throw new RuntimeException("Not enough bytes, need "

                    + bytes.length + ", got " + numBytes);

            }

            System.arraycopy(this.srcBytes, this.srcBytes.length - numBytes, bytes, 0, bytes.length);

            numBytes -= bytes.length;

        }

    }

    public static void main(String[] args) throws Exception {

        //for (Provider provider : Security.getProviders()) {

        Provider p = Security.getProvider("SunRsaSign");

        Signature sig;

        try {

            sig = Signature.getInstance("RSASSA-PSS", p);

        } catch (NoSuchAlgorithmException e) {

            System.out.println("Skip testing RSASSA-PSS" +

                " due to no support");

            return;

        }

        boolean success = true;

        for (String f : testFiles) {

            System.out.println("[INPUT FILE " + f + "]");

            try {

                success &= runTest(SigRecord.read(f), sig);

            } catch (IOException e) {

                System.out.println("Unexpected exception: " + e);

                e.printStackTrace(System.out);

                success = false;

            }

        }

        if (!success) {

            throw new RuntimeException("One or more test failed");

        }

        System.out.println("Test passed");

    }

    /*

     * Run all the tests in the data list with specified algorithm

     */

    static boolean runTest(List<SigRecord> records, Signature sig) throws Exception {

        boolean success = true;

        KeyFactory kf = KeyFactory.getInstance("RSA", sig.getProvider());

        for (SigRecord sr : records) {

            System.out.println("==Testing Record : " + sr + "==");

            PrivateKey privKey = kf.generatePrivate(sr.privKeySpec);

            PublicKey pubKey = kf.generatePublic(sr.pubKeySpec);

            success &= check(sig, privKey, pubKey, sr.testVectors);

            System.out.println("==Done==");

        }

        return success;

    }

    /*

     * Generate the signature, check against known values and verify.

     */

    static boolean check(Signature sig, PrivateKey privKey, PublicKey pubKey,

        List<SigRecord.SigVector> vectors) throws Exception {

        boolean success = true;

        for (SigRecord.SigVector v : vectors) {

            System.out.println("\tAgainst " + v.mdAlg);

            byte[] msgBytes = SigRecord.toByteArray(v.msg);

            byte[] expSigBytes = SigRecord.toByteArray(v.sig);

            MyKnownRandomSrc saltSrc = new MyKnownRandomSrc(v.salt);

            sig.initSign(privKey, saltSrc);

            PSSParameterSpec params = new PSSParameterSpec(v.mdAlg, "MGF1",

                new MGF1ParameterSpec(v.mdAlg), saltSrc.numBytes, 1);

            sig.setParameter(params);

            sig.update(msgBytes);

            byte[] actualSigBytes = sig.sign();

            // Check if the supplied salt bytes are used up

            if (saltSrc.numBytes != 0) {

                throw new RuntimeException("Error: salt length mismatch! "

                    + saltSrc.numBytes + " bytes leftover");

            }

            success &= MessageDigest.isEqual(actualSigBytes, expSigBytes);

            if (!success) {

                System.out.println("\tFailed:");

                System.out.println("\tSHAALG       = " + v.mdAlg);

                System.out.println("\tMsg          = " + v.msg);

                System.out.println("\tSalt          = " + v.salt);

                System.out.println("\tExpected Sig = " + v.sig);

                System.out.println("\tActual Sig   = " + SigRecord.toHexString(actualSigBytes));

            } else {

                System.out.println("\t" + v.mdAlg + " Test Vector Passed");

            }

        }

        return success;

    }

}