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import jdk.test.lib.RandomFactory;

/*

 * @test

 * @key randomness

 * @summary This test validates signature verification

 *          Signature.verify(byte[], int, int). The test uses RandomFactory to

 *          get random set of clear text data to sign. After the signature

 *          generation, the test tries to verify signature with the above API

 *          and passing in different signature offset (0, 33, 66, 99).

 * @library /test/lib

 * @build jdk.test.lib.RandomFactory

 * @run main Offsets SUN NONEwithDSA

 * @run main Offsets SUN SHA1withDSA

 * @run main Offsets SUN SHA224withDSA

 * @run main Offsets SUN SHA256withDSA

 */

public class Offsets {

    private final int size;

    private final byte[] cleartext;

    private final PublicKey pubkey;

    private final Signature signature;

    private final byte[] signed;

    private Offsets(Signature signature, PublicKey pubkey, PrivateKey privkey,

            int size, byte[] cleartext) throws InvalidKeyException,

                SignatureException {

        this.pubkey = pubkey;

        this.signature = signature;

        this.size = size;

        this.cleartext = cleartext;

        signature.initSign(privkey);

        signature.update(cleartext, 0, size);

        signed = signature.sign();

    }

    int getDataSize() {

        return size;

    }

    int getSignatureLength() {

        return signed.length;

    }

    byte[] shiftSignData(int offset) {

        byte[] testSignData = new byte[offset + signed.length];

        System.arraycopy(signed, 0, testSignData, offset,

                signed.length);

        return testSignData;

    }

    boolean verifySignature(byte[] sigData, int sigOffset, int sigLength,

            int updateOffset, int updateLength)

        signature.initVerify(pubkey);

        signature.update(cleartext, updateOffset, updateLength);

        return signature.verify(sigData, sigOffset, sigLength);

    }

    static Offsets init(String provider, String algorithm)

            throws NoSuchAlgorithmException, NoSuchProviderException,

            InvalidKeyException, SignatureException {

        // fill the cleartext data with random bytes

        byte[] cleartext = new byte[100];

        RandomFactory.getRandom().nextBytes(cleartext);

        // NONEwith requires input to be of 20 bytes

        int size = algorithm.contains("NONEwith") ? 20 : 100;

        // create signature instance

        Signature signature = Signature.getInstance(algorithm, provider);

        String keyAlgo;

        int keySize = 2048;

        if (algorithm.contains("RSA")) {

            keyAlgo = "RSA";

        } else if (algorithm.contains("ECDSA")) {

            keyAlgo = "EC";

            keySize = 256;

        } else if (algorithm.contains("DSA")) {

            keyAlgo = "DSA";

            if (algorithm.startsWith("SHAwith") ||

                    algorithm.startsWith("SHA1with")) {

                keySize = 1024;

            }

        } else {

            throw new RuntimeException("Test doesn't support this signature "

                    + "algorithm: " + algorithm);

        }

        KeyPairGenerator kpg = KeyPairGenerator.getInstance(keyAlgo, provider);

        kpg.initialize(keySize);

        KeyPair kp = kpg.generateKeyPair();

        PublicKey pubkey = kp.getPublic();

        PrivateKey privkey = kp.getPrivate();

        return new Offsets(signature, pubkey, privkey, size, cleartext);

    }

    public static void main(String[] args) throws NoSuchAlgorithmException,

            InvalidKeyException, SignatureException {

        if (args.length < 2) {

            throw new RuntimeException("Wrong parameters");

        }

        boolean result = true;

        try {

            Offsets test = init(args[0], args[1]);

            // We are trying 3 different offsets, data size has nothing to do

            // with signature length

            for (int chunk = 3; chunk > 0; chunk--) {

                int signOffset = test.getDataSize() / chunk;

                System.out.println("Running test with offset " + signOffset);

                byte[] signData = test.shiftSignData(signOffset);

                boolean success = test.verifySignature(signData, signOffset,

                        test.getSignatureLength(), 0, test.getDataSize());

                if (success) {

                    System.out.println("Successfully verified with offset "

                            + signOffset);

                } else {

                    System.out.println("Verification failed with offset "

                            + signOffset);

                    result = false;

                }

            }

            // save signature to offset 0

            byte[] signData = test.shiftSignData(0);

            // Negative tests

            // Test signature offset 0.

            // Wrong test data will be passed to update,

            // so signature verification should fail.

            for (int chunk = 3; chunk > 0; chunk--) {

                int dataOffset = (test.getDataSize() - 1) / chunk;

                boolean success;

                try {

                    success = test.verifySignature(signData, 0,

                            test.getSignatureLength(), dataOffset,

                            (test.getDataSize() - dataOffset));

                } catch (SignatureException e) {

                    // Since we are trying different data size, it can throw

                    // SignatureException

                    success = false;

                }

                if (!success) {

                    System.out.println("Signature verification failed "

                            + "as expected, with data offset " + dataOffset

                            + " and length "

                            + (test.getDataSize() - dataOffset));

                } else {

                    System.out.println("Signature verification "

                            + "should not succeed, with data offset "

                            + dataOffset + " and length "

                            + (test.getDataSize() - dataOffset));

                    result = false;

                }

            }

            // Tests with manipulating offset and length

            result &= Offsets.checkFailure(test, signData, -1,

                    test.getSignatureLength());

            result &= Offsets.checkFailure(test, signData, 0,

                    test.getSignatureLength() - 1);

            result &= Offsets.checkFailure(test, signData,

                    test.getSignatureLength() + 1, test.getSignatureLength());

            result &= Offsets.checkFailure(test, signData, 0,

                    test.getSignatureLength() + 1);

            result &= Offsets.checkFailure(test, signData, 0, 0);

            result &= Offsets.checkFailure(test, signData, 0, -1);

            result &= Offsets.checkFailure(test, signData,

                    2147483646, test.getSignatureLength());

            result &= Offsets.checkFailure(test, null, 0,

                    test.getSignatureLength());

        } catch (NoSuchProviderException nspe) {

            System.out.println("No such provider: " + nspe);

        }

        if (!result) {

            throw new RuntimeException("Some test cases failed");

        }

    }

    static boolean checkFailure(Offsets test, byte[] signData, int offset,

            int length) {

        boolean success;

        try {

            success = test.verifySignature(signData, offset, length, 0,

                    test.getDataSize());

        } catch (IllegalArgumentException | SignatureException e) {

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

            success = false;

        } catch (InvalidKeyException e) {

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

            return false;

        }

        if (!success) {

            System.out.println("Signature verification failed as expected, "

                    + "with signature offset " + offset + " and length "

                    + length);

            return true;

        } else {

            System.out.println("Signature verification should not succeed, "

                    + "with signature offset " + offset + " and length "

                    + length);

            return false;

        }

    }

}