// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename       : Dump.cs
// Author(s)      : Rebecca Wallander <sakcheen+github@gmail.com>
//
// --[ Description ] ----------------------------------------------------------
//
//     SCSI read commands related to Content Scrambling System.
//
// --[ License ] --------------------------------------------------------------
//
//     Permission is hereby granted, free of charge, to any person obtaining a
//     copy of this software and associated documentation files (the
//     "Software"), to deal in the Software without restriction, including
//     without limitation the rights to use, copy, modify, merge, publish,
//     distribute, sublicense, and/or sell copies of the Software, and to
//     permit persons to whom the Software is furnished to do so, subject to
//     the following conditions:
//
//     The above copyright notice and this permission notice shall be included
//     in all copies or substantial portions of the Software.
//
//     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
//     OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
//     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
//     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
//     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
//     TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
//     SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
// ----------------------------------------------------------------------------
// Copyright © 2020-2023 Rebecca Wallander
// ****************************************************************************/

using System;
using System.Linq;
using Aaru.Console;
using Aaru.Decoders.DVD;
using Aaru.Devices;

namespace Aaru.Decryption.DVD
{
    public sealed class Dump
    {
        const    byte   KEY_SIZE       = 5;
        const    byte   CHALLENGE_SIZE = 2 * KEY_SIZE;
        readonly Device _dev;

        public Dump(Device dev)
        {
            _dev   = dev;
            BusKey = Array.Empty<byte>();
            Agid   = 0;
        }

        public byte   Agid   { get; private set; }
        public byte[] BusKey { get; private set; }

        /// <summary>Returns the Authentication Success Flag of the logical unit.</summary>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        /// <param name="buffer">Buffer where the Authentication Success Flag will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        public bool ReadAsf(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, uint timeout,
                            out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[8];

            cdb[0]  = (byte)ScsiCommands.ReportKey;
            cdb[7]  = (byte)keyClass;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((byte)CssReportKeyFormat.Asf ^ ((Agid & 0x03) << 6));

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "REPORT ASF (AGID: {1}, Sense: {2}, Last Error: {3}) took {0} ms.", duration,
                                       Agid, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Returns the Regional Playback Control State of the logical unit.</summary>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        /// <param name="buffer">Buffer where the Regional Playback Control State will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        public bool ReadRpc(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, uint timeout,
                            out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[8];

            cdb[0]  = (byte)ScsiCommands.ReportKey;
            cdb[7]  = (byte)keyClass;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((byte)CssReportKeyFormat.RpcState ^ ((Agid & 0x03) << 6));

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "REPORT ASF (AGID: {1}, Sense: {2}, Last Error: {3}) took {0} ms.", duration,
                                       Agid, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Invalidates an Authentication Grant ID.</summary>
        /// <param name="buffer">Buffer where the Regional Playback Control State will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        public bool InvalidateAgid(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, uint timeout,
                                   out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = Array.Empty<byte>();

            cdb[0]  = (byte)ScsiCommands.ReportKey;
            cdb[7]  = (byte)keyClass;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((byte)CssReportKeyFormat.InvalidateAgid ^ ((Agid & 0x03) << 6));

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "INVALIDATE AGID (AGID: {1}, Sense: {2}, Last Error: {3}) took {0} ms.",
                                       duration, Agid, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Returns a valid Authentication Grant ID for CSS/CPPM.</summary>
        /// <param name="buffer">Buffer where the Regional Playback Control State will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        public bool ReportAgidCssCppm(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, uint timeout,
                                      out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[8];

            cdb[0]  = (byte)ScsiCommands.ReportKey;
            cdb[7]  = (byte)keyClass;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((byte)CssReportKeyFormat.AgidForCssCppm ^ ((Agid & 0x03) << 6));

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "REPORT AGID CSS/CPPM (AGID: {1}, Sense: {2}, Last Error: {3}) took {0} ms.",
                                       duration, Agid, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Returns KEY1 from the logical unit.</summary>
        /// <param name="buffer">Buffer where the Regional Playback Control State will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        public bool ReportKey1(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, uint timeout,
                               out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[12];

            cdb[0]  = (byte)ScsiCommands.ReportKey;
            cdb[7]  = (byte)keyClass;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((byte)CssReportKeyFormat.Key1 ^ ((Agid & 0x03) << 6));

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "REPORT KEY1 (AGID: {1}, Sense: {2}, Last Error: {3}) took {0} ms.", duration,
                                       Agid, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Returns the challenge from the logical unit.</summary>
        /// <param name="buffer">Buffer where the Regional Playback Control State will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        public bool ReportChallenge(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, uint timeout,
                                    out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[16];

            cdb[0]  = (byte)ScsiCommands.ReportKey;
            cdb[7]  = (byte)keyClass;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((byte)CssReportKeyFormat.ChallengeKey ^ ((Agid & 0x03) << 6));

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "REPORT CHALLENGE (AGID: {1}, Sense: {2}, Last Error: {3}) took {0} ms.",
                                       duration, Agid, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Send a challenge to the logical unit.</summary>
        /// <param name="buffer">Buffer where the Regional Playback Control State will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="challengeKey">The challenge; can be any 10 bytes.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        public bool SendChallenge(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass,
                                  byte[] challengeKey, uint timeout, out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[16];

            cdb[0]     = (byte)ScsiCommands.SendKey;
            cdb[7]     = (byte)keyClass;
            cdb[8]     = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]     = (byte)(buffer.Length & 0xFF);
            cdb[10]    = (byte)((byte)CssSendKeyFormat.ChallengeKey ^ ((Agid & 0x03) << 6));
            buffer[0]  = (byte)(((buffer.Length - 2) & 0xFF00) >> 8);
            buffer[1]  = (byte)((buffer.Length - 2) & 0xFF);
            buffer[4]  = challengeKey[9];
            buffer[5]  = challengeKey[8];
            buffer[6]  = challengeKey[7];
            buffer[7]  = challengeKey[6];
            buffer[8]  = challengeKey[5];
            buffer[9]  = challengeKey[4];
            buffer[10] = challengeKey[3];
            buffer[11] = challengeKey[2];
            buffer[12] = challengeKey[1];
            buffer[13] = challengeKey[0];

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.Out, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "SEND CHALLENGE (AGID: {1}, Challenge {2}, Sense: {3}, Last Error: {4}) took {0} ms.",
                                       duration, Agid, challengeKey, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Send KEY2 to the logical unit.</summary>
        /// <param name="buffer">Buffer where the Regional Playback Control State will be stored.</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="key2">The KEY2 message.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        public bool SendKey2(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, byte[] key2,
                             uint timeout, out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[12];

            cdb[0]    = (byte)ScsiCommands.SendKey;
            cdb[7]    = (byte)keyClass;
            cdb[8]    = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]    = (byte)(buffer.Length & 0xFF);
            cdb[10]   = (byte)((byte)CssSendKeyFormat.Key2 ^ ((Agid & 0x03) << 6));
            buffer[0] = (byte)(((buffer.Length - 2) & 0xFF00) >> 8);
            buffer[1] = (byte)((buffer.Length - 2) & 0xFF);
            buffer[4] = key2[4];
            buffer[5] = key2[3];
            buffer[6] = key2[2];
            buffer[7] = key2[1];
            buffer[8] = key2[0];

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.Out, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device",
                                       "SEND CHALLENGE (AGID: {1}, KEY2 {2}, Sense: {3}, Last Error: {4}) took {0} ms.",
                                       duration, Agid, key2, sense, _dev.LastError);

            return sense;
        }

        /// <summary>Returns the encrypted disc key of the MMC logical unit</summary>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        /// <param name="buffer">Buffer where the bus key will be stored</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        public bool ReadDiscKey(out byte[] buffer, out byte[] senseBuffer, uint timeout, out double duration)
        {
            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[2052];

            cdb[0]  = (byte)ScsiCommands.ReadDiscStructure;
            cdb[1]  = (byte)MmcDiscStructureMediaType.Dvd & 0x0F;
            cdb[6]  = 0;
            cdb[7]  = (byte)MmcDiscStructureFormat.DiscKey;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((Agid & 0x03) << 6);

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            return sense;
        }

        /// <summary>Returns the bus key of the MMC logical unit</summary>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        /// <param name="buffer">Buffer where the bus key will be stored</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="protectionType">The type of protection the logical unit reports</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        public bool ReadBusKey(out byte[] buffer, out byte[] senseBuffer, CopyrightType protectionType, uint timeout,
                               out double duration)
        {
            duration    = 0;
            buffer      = Array.Empty<byte>();
            senseBuffer = new byte[64];

            bool   sense     = false;
            byte[] challenge = new byte[CHALLENGE_SIZE];
            byte[] key1      = new byte[KEY_SIZE];
            byte   variant   = 0;

            for(byte i = 0; i < 4; i++)
            {
                // Invalidate AGID to reset any previous drive communications
                Agid = i;

                sense = InvalidateAgid(out buffer, out senseBuffer, DvdCssKeyClass.DvdCssCppmOrCprm, timeout,
                                       out duration);

                // Get AGID
                if(protectionType == CopyrightType.CSS)
                {
                    sense = ReportAgidCssCppm(out buffer, out senseBuffer, DvdCssKeyClass.DvdCssCppmOrCprm, timeout,
                                              out duration);
                }

                if(protectionType == CopyrightType.CPRM)
                {
                    throw new NotImplementedException();
                }

                if(!sense)
                {
                    Agid = (byte)(buffer[7] >> 6);

                    break;
                }
            }

            if(sense)
            {
                return true;
            }

            for(byte i = 0; i < CHALLENGE_SIZE; i++)
                challenge[i] = i;

            sense = SendChallenge(out buffer, out senseBuffer, DvdCssKeyClass.DvdCssCppmOrCprm, challenge, timeout,
                                  out duration);

            if(sense)
            {
                return true;
            }

            sense = ReportKey1(out buffer, out senseBuffer, DvdCssKeyClass.DvdCssCppmOrCprm, timeout, out duration);

            if(sense)
            {
                return true;
            }

            for(byte i = 0; i < KEY_SIZE; i++)
                key1[i] = buffer[8 - i];

            for(byte i = 0; i < 32; i++)
            {
                CSS.EncryptKey(DvdCssKeyType.Key1, i, challenge, out byte[] keyCheck);

                if(key1.SequenceEqual(keyCheck))
                {
                    variant = i;

                    break;
                }

                if(i >= 31)
                {
                    senseBuffer = Array.Empty<byte>();

                    return true;
                }
            }

            sense = ReportChallenge(out buffer, out senseBuffer, DvdCssKeyClass.DvdCssCppmOrCprm, timeout,
                                    out duration);

            if(sense)
            {
                return true;
            }

            for(byte i = 0; i < CHALLENGE_SIZE; i++)
                challenge[i] = buffer[13 - i];

            CSS.EncryptKey(DvdCssKeyType.Key2, variant, challenge, out byte[] key2);

            sense = SendKey2(out buffer, out senseBuffer, DvdCssKeyClass.DvdCssCppmOrCprm, key2, timeout, out duration);

            if(sense)
            {
                return true;
            }

            key1.CopyTo(challenge, 0);
            key2.CopyTo(challenge, key1.Length);
            CSS.EncryptKey(DvdCssKeyType.BusKey, variant, challenge, out buffer);

            BusKey = buffer;

            return false;
        }

        /// <summary>Reads a title key for a sector on the disc.</summary>
        /// <param name="buffer">Buffer where the bus key will be stored</param>
        /// <param name="senseBuffer">Sense buffer.</param>
        /// <param name="keyClass">Key class.</param>
        /// <param name="address">The sector address to get the key for.</param>
        /// <param name="timeout">Timeout in seconds.</param>
        /// <param name="duration">Duration in milliseconds it took for the device to execute the command.</param>
        /// <returns><c>true</c> if the command failed and <paramref name="senseBuffer" /> contains the sense buffer.</returns>
        public bool ReadTitleKey(out byte[] buffer, out byte[] senseBuffer, DvdCssKeyClass keyClass, ulong address,
                                 uint timeout, out double duration)
        {
            // We need to be in a bus key state to read title keys. Only CSS has title keys.
            ReadBusKey(out buffer, out senseBuffer, CopyrightType.CSS, timeout, out duration);

            BusKey = buffer;

            senseBuffer = new byte[64];
            byte[] cdb = new byte[12];
            buffer = new byte[12];

            cdb[0]  = (byte)ScsiCommands.ReportKey;
            cdb[2]  = (byte)((address & 0xFF000000) >> 24);
            cdb[3]  = (byte)((address & 0xFF0000)   >> 16);
            cdb[4]  = (byte)((address & 0xFF00)     >> 8);
            cdb[5]  = (byte)(address & 0xFF);
            cdb[7]  = (byte)keyClass;
            cdb[8]  = (byte)((buffer.Length & 0xFF00) >> 8);
            cdb[9]  = (byte)(buffer.Length & 0xFF);
            cdb[10] = (byte)((byte)CssReportKeyFormat.TitleKey ^ ((Agid & 0x03) << 6));

            _dev.SendScsiCommand(cdb, ref buffer, out senseBuffer, timeout, ScsiDirection.In, out duration,
                                 out bool sense);

            AaruConsole.DebugWriteLine("SCSI Device", "GET TITLE KEY (AGID: {1}, LBA: {2}, Sense: {3}) took {0} ms.",
                                       duration, Agid, address, sense);

            return sense;
        }
    }
}