/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.internal.net.eap.statemachine;

import static android.net.eap.EapSessionConfig.EapMethodConfig.EAP_TYPE_MSCHAP_V2;

import static com.android.internal.net.eap.message.EapMessage.EAP_CODE_REQUEST;
import static com.android.internal.net.eap.message.EapTestMessageDefinitions.EAP_MSCHAP_V2_CHALLENGE_RESPONSE;
import static com.android.internal.net.eap.message.EapTestMessageDefinitions.ID_INT;
import static com.android.internal.net.eap.message.EapTestMessageDefinitions.MSCHAP_V2_AUTHENTICATOR_CHALLENGE;
import static com.android.internal.net.eap.message.EapTestMessageDefinitions.MSCHAP_V2_ID_INT;
import static com.android.internal.net.eap.message.EapTestMessageDefinitions.MSCHAP_V2_PEER_CHALLENGE;
import static com.android.internal.net.eap.message.mschapv2.EapMsChapV2PacketDefinitions.SERVER_NAME_BYTES;
import static com.android.internal.net.eap.message.mschapv2.EapMsChapV2TypeData.EapMsChapV2ChallengeRequest.TYPE_DATA_HEADER_SIZE;
import static com.android.internal.net.eap.message.mschapv2.EapMsChapV2TypeData.EapMsChapV2ChallengeRequest.VALUE_SIZE;

import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import com.android.internal.net.eap.EapResult;
import com.android.internal.net.eap.EapResult.EapError;
import com.android.internal.net.eap.EapResult.EapResponse;
import com.android.internal.net.eap.exceptions.mschapv2.EapMsChapV2ParsingException;
import com.android.internal.net.eap.message.EapData;
import com.android.internal.net.eap.message.EapMessage;
import com.android.internal.net.eap.message.mschapv2.EapMsChapV2TypeData.EapMsChapV2ChallengeRequest;
import com.android.internal.net.eap.message.mschapv2.EapMsChapV2TypeData.EapMsChapV2TypeDataDecoder.DecodeResult;
import com.android.internal.net.eap.statemachine.EapMsChapV2MethodStateMachine.ValidateAuthenticatorState;

import org.junit.Before;
import org.junit.Test;

public class EapMsChapV2ChallengeStateTest extends EapMsChapV2StateTest {
    @Before
    @Override
    public void setUp() {
        super.setUp();

        mStateMachine.transitionTo(mStateMachine.new ChallengeState());
    }

    @Test
    public void testProcessChallenge() throws Exception {
        EapData eapData = new EapData(EAP_TYPE_MSCHAP_V2, DUMMY_TYPE_DATA);
        EapMessage eapMessage = new EapMessage(EAP_CODE_REQUEST, ID_INT, eapData);

        EapMsChapV2ChallengeRequest challengeRequest =
                new EapMsChapV2ChallengeRequest(
                        MSCHAP_V2_ID_INT,
                        TYPE_DATA_HEADER_SIZE + VALUE_SIZE + SERVER_NAME_BYTES.length,
                        MSCHAP_V2_AUTHENTICATOR_CHALLENGE,
                        SERVER_NAME_BYTES);
        doReturn(new DecodeResult<>(challengeRequest))
                .when(mMockTypeDataDecoder)
                .decodeChallengeRequest(any(String.class), eq(DUMMY_TYPE_DATA));

        doAnswer(invocation -> {
            byte[] dst = invocation.getArgument(0);
            System.arraycopy(MSCHAP_V2_PEER_CHALLENGE, 0, dst, 0, MSCHAP_V2_PEER_CHALLENGE.length);
            return null;
        }).when(mMockSecureRandom).nextBytes(eq(new byte[MSCHAP_V2_PEER_CHALLENGE.length]));

        EapResult result = mStateMachine.process(eapMessage);
        EapResponse eapResponse = (EapResponse) result;
        assertArrayEquals(EAP_MSCHAP_V2_CHALLENGE_RESPONSE, eapResponse.packet);
        assertTrue(mStateMachine.getState() instanceof ValidateAuthenticatorState);
        verify(mMockSecureRandom).nextBytes(any(byte[].class));
        verify(mMockTypeDataDecoder).decodeChallengeRequest(any(String.class), eq(DUMMY_TYPE_DATA));
    }

    @Test
    public void testIncorrectTypeData() throws Exception {
        EapData eapData = new EapData(EAP_TYPE_MSCHAP_V2, DUMMY_TYPE_DATA);
        EapMessage eapMessage = new EapMessage(EAP_CODE_REQUEST, ID_INT, eapData);

        when(mMockTypeDataDecoder.decodeChallengeRequest(any(String.class), eq(DUMMY_TYPE_DATA)))
                .thenReturn(
                        new DecodeResult<>(
                                new EapError(
                                        new EapMsChapV2ParsingException("incorrect type data"))));

        EapResult result = mStateMachine.process(eapMessage);
        EapError eapError = (EapError) result;
        assertTrue(eapError.cause instanceof EapMsChapV2ParsingException);
        verify(mMockTypeDataDecoder).decodeChallengeRequest(any(String.class), eq(DUMMY_TYPE_DATA));
    }
}