package org.bouncycastle.jce.provider.test;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.security.Key;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.asn1.cryptopro.CryptoProObjectIdentifiers;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.encoders.Hex;
import org.bouncycastle.util.test.SimpleTest;

/**
 * basic test class for the GOST28147 cipher
 */
public class GOST28147Test
    extends SimpleTest
{
    static String[] cipherTests =
    {
        "256",
        "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
        "4e6f77206973207468652074696d6520666f7220616c6c20",
        "281630d0d5770030068c252d841e84149ccc1912052dbc02",

        "256",
        "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
        "4e6f77206973207468652074696d65208a920c6ed1a804f5",
        "88e543dfc04dc4f764fa7b624741cec07de49b007bf36065"
    };

    public String getName()
    {
        return "GOST28147";
    }

    public void testECB(
        int         strength,
        byte[]      keyBytes,
        byte[]      input,
        byte[]      output)
        throws Exception
    {
        Key                     key;
        Cipher                  in, out;
        CipherInputStream       cIn;
        CipherOutputStream      cOut;
        ByteArrayInputStream    bIn;
        ByteArrayOutputStream   bOut;

        key = new SecretKeySpec(keyBytes, "GOST28147");

        in = Cipher.getInstance("GOST28147/ECB/NoPadding", "BC");
        out = Cipher.getInstance("GOST28147/ECB/NoPadding", "BC");
        out.init(Cipher.ENCRYPT_MODE, key);
        in.init(Cipher.DECRYPT_MODE, key);

        //
        // encryption pass
        //
        bOut = new ByteArrayOutputStream();

        cOut = new CipherOutputStream(bOut, out);

        for (int i = 0; i != input.length / 2; i++)
        {
            cOut.write(input[i]);
        }
        cOut.write(input, input.length / 2, input.length - input.length / 2);
        cOut.close();

        byte[]    bytes;

        bytes = bOut.toByteArray();

        if (!areEqual(bytes, output))
        {
            fail("GOST28147 failed encryption - expected " + new String(Hex.encode(output)) + " got " + new String(Hex.encode(bytes)));
        }

        //
        // decryption pass
        //
        bIn = new ByteArrayInputStream(bytes);

        cIn = new CipherInputStream(bIn, in);

        DataInputStream dIn = new DataInputStream(cIn);

        bytes = new byte[input.length];

        for (int i = 0; i != input.length / 2; i++)
        {
            bytes[i] = (byte)dIn.read();
        }
        dIn.readFully(bytes, input.length / 2, bytes.length - input.length / 2);

        if (!areEqual(bytes, input))
        {
            fail("GOST28147 failed decryption - expected " + new String(Hex.encode(input)) + " got " + new String(Hex.encode(bytes)));
        }
    }

    public void testCFB(
        int         strength,
        byte[]      keyBytes,
        byte[]      input,
        byte[]      output)
        throws Exception
    {
        Key                     key;
        Cipher                  in, out;
        CipherInputStream       cIn;
        CipherOutputStream      cOut;
        ByteArrayInputStream    bIn;
        ByteArrayOutputStream   bOut;

        key = new SecretKeySpec(keyBytes, "GOST28147");

        in = Cipher.getInstance("GOST28147/CFB8/NoPadding", "BC");
        out = Cipher.getInstance("GOST28147/CFB8/NoPadding", "BC");
        byte[] iv = {1,2,3,4,5,6,7,8};
        
        out.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
        in.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));

        //
        // encryption pass
        //
        bOut = new ByteArrayOutputStream();

        cOut = new CipherOutputStream(bOut, out);

        for (int i = 0; i != input.length / 2; i++)
        {
            cOut.write(input[i]);
        }
        cOut.write(input, input.length / 2, input.length - input.length / 2);
        cOut.close();

        byte[]    bytes;

        bytes = bOut.toByteArray();

        if (!areEqual(bytes, output))
        {
            fail("GOST28147 failed encryption - expected " + new String(Hex.encode(output)) + " got " + new String(Hex.encode(bytes)));
        }

        //
        // decryption pass
        //
        bIn = new ByteArrayInputStream(bytes);

        cIn = new CipherInputStream(bIn, in);

        DataInputStream dIn = new DataInputStream(cIn);

        bytes = new byte[input.length];

        for (int i = 0; i != input.length / 2; i++)
        {
            bytes[i] = (byte)dIn.read();
        }
        dIn.readFully(bytes, input.length / 2, bytes.length - input.length / 2);

        if (!areEqual(bytes, input))
        {
            fail("GOST28147 failed decryption - expected " + new String(Hex.encode(input)) + " got " + new String(Hex.encode(bytes)));
        }
    }

    private void oidTest()
    {
        String[] oids = {
                CryptoProObjectIdentifiers.gostR28147_gcfb.getId(),
        };
        
        String[] names = {
            "GOST28147/GCFB/NoPadding"
        };
        
        try
        {
            
            byte[]          data = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
            IvParameterSpec ivSpec = new IvParameterSpec(new byte[8]);
            
            for (int i = 0; i != oids.length; i++)
            {
                Cipher c1 = Cipher.getInstance(oids[i], "BC");
                Cipher c2 = Cipher.getInstance(names[i], "BC");
                KeyGenerator kg = KeyGenerator.getInstance(oids[i], "BC");
                
                SecretKey k = kg.generateKey();
                
                c1.init(Cipher.ENCRYPT_MODE, k, ivSpec);
                c2.init(Cipher.DECRYPT_MODE, k, ivSpec);

                byte[] result = c2.doFinal(c1.doFinal(data));

                if (!areEqual(data, result))
                {
                    fail("failed OID test");
                }
            }
        }
        catch (Exception ex)
        {
            fail("failed exception " + ex.toString(), ex);
        }
    }
    
        public void performTest() 
            throws Exception
        {
            for (int i = 0; i != cipherTests.length; i += 8)
            {
                testECB(Integer.parseInt(cipherTests[i]),
                                Hex.decode(cipherTests[i + 1]),
                                Hex.decode(cipherTests[i + 2]),
                                Hex.decode(cipherTests[i + 3]));

                testCFB(Integer.parseInt(cipherTests[i + 4]),
                                Hex.decode(cipherTests[i + 4 + 1]),
                                Hex.decode(cipherTests[i + 4 + 2]),
                                Hex.decode(cipherTests[i + 4 + 3]));

                oidTest();
            }

            Mac mac = Mac.getInstance("GOST28147MAC", "BC");

            mac.init(new SecretKeySpec(Hex.decode("0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"), "GOST28147"));

            if (!Arrays.areEqual(Hex.decode("1b69996e"), mac.doFinal(Hex.decode("4e6f77206973207468652074696d6520666f7220616c6c20"))))
            {
                fail("mac test failed.");
            }
        }

        public static void main(
            String[]    args)
        {
            Security.addProvider(new BouncyCastleProvider());

            runTest(new GOST28147Test());
        }
    }