NDecrypt/NDecrypt.Core/DecryptArgs.cs

using System;
using System.IO;
using SabreTools.Hashing;
using SabreTools.IO.Encryption;
using SabreTools.IO.Extensions;

namespace NDecrypt.Core
{
    public class DecryptArgs
    {
        #region Common Fields

        /// <summary>
        /// Represents if all of the keys have been initialized properly
        /// </summary>
        public bool? IsReady { get; private set; }

        #endregion

        #region DS-Specific Fields

        /// <summary>
        /// Blowfish Table
        /// </summary>
        public byte[] NitroEncryptionData { get; private set; } = [];

        #endregion

        #region 3DS-Specific Fields

        /// <summary>
        /// AES Hardware Constant
        /// </summary>
        public byte[] AESHardwareConstant { get; private set; } = [];

        /// <summary>
        /// KeyX 0x18 (New 3DS 9.3)
        /// </summary>
        public byte[] KeyX0x18 { get; private set; } = [];

        /// <summary>
        /// Dev KeyX 0x18 (New 3DS 9.3)
        /// </summary>
        public byte[] DevKeyX0x18 { get; private set; } = [];

        /// <summary>
        /// KeyX 0x1B (New 3DS 9.6)
        /// </summary>
        public byte[] KeyX0x1B { get; private set; } = [];

        /// <summary>
        /// Dev KeyX 0x1B New 3DS 9.6)
        /// </summary>
        public byte[] DevKeyX0x1B { get; private set; } = [];

        /// <summary>
        /// KeyX 0x25 (> 7.x)
        /// </summary>
        public byte[] KeyX0x25 { get; private set; } = [];

        /// <summary>
        /// Dev KeyX 0x25 (> 7.x)
        /// </summary>
        public byte[] DevKeyX0x25 { get; private set; } = [];

        /// <summary>
        /// KeyX 0x2C (< 6.x)
        /// </summary>
        public byte[] KeyX0x2C { get; private set; } = [];

        /// <summary>
        /// Dev KeyX 0x2C (< 6.x)
        /// </summary>
        public byte[] DevKeyX0x2C { get; private set; } = [];

        #endregion

        #region Internal Test Values

        /// <summary>
        /// Expected hash for NitroEncryptionData
        /// </summary>
        private static readonly byte[] ExpectedNitroSha512Hash =
        [
            0x1A, 0xD6, 0x40, 0x21, 0xFC, 0x3D, 0x1A, 0x9A,
            0x9B, 0xC0, 0x88, 0x8E, 0x2E, 0x68, 0xDE, 0x4E,
            0x8A, 0x60, 0x6B, 0x86, 0x63, 0x22, 0xD2, 0xC7,
            0xC6, 0xD7, 0xD6, 0xCE, 0x65, 0xF5, 0xBA, 0xA7,
            0xEA, 0x69, 0x63, 0x7E, 0xC9, 0xE4, 0x57, 0x7B,
            0x01, 0xFD, 0xCE, 0xC2, 0x26, 0x3B, 0xD9, 0x0D,
            0x84, 0x57, 0xC2, 0x00, 0xB8, 0x56, 0x9F, 0xE5,
            0x56, 0xDA, 0x8D, 0xDE, 0x84, 0xB8, 0x8E, 0xE4,
        ];

        /// <summary>
        /// Initial value for key validation tests
        /// </summary>
        private static readonly byte[] TestIV =
        [
            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
            0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
        ];

        /// <summary>
        /// Pattern to use for key validation tests
        /// </summary>
        private static readonly byte[] TestPattern =
        [
            0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08,
            0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
            0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08,
            0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
            0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08,
            0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
            0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08,
            0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
        ];

        /// <summary>
        /// Expected output value for KeyX0x18
        /// </summary>
        private static readonly byte[] ExpectedKeyX0x18 =
        [
            0x06, 0xF1, 0xB2, 0x3B, 0x12, 0xAD, 0x80, 0xC1,
            0x13, 0xC6, 0x18, 0x3D, 0x27, 0xB8, 0xB9, 0x95,
            0x49, 0x73, 0x59, 0x82, 0xEF, 0xFE, 0x16, 0x48,
            0x91, 0x2A, 0x89, 0x55, 0x9A, 0xDC, 0x3C, 0xA0,
            0x84, 0x46, 0x14, 0xE0, 0x16, 0x59, 0x8E, 0x4F,
            0xC2, 0x6C, 0x52, 0xA4, 0x7D, 0xAD, 0x4F, 0x23,
            0xF1, 0xC6, 0x99, 0x44, 0x39, 0xB7, 0x42, 0xF0,
            0x1F, 0xBB, 0x02, 0xF6, 0x0A, 0x8A, 0xC2, 0x9A,
        ];

        /// <summary>
        /// Expected output value for DevKeyX0x18
        /// </summary>
        private static readonly byte[] ExpectedDevKeyX0x18 =
        [
            0x99, 0x6E, 0x3C, 0x54, 0x97, 0x3C, 0xEA, 0xE8,
            0xBA, 0xAE, 0x18, 0x5C, 0x93, 0x27, 0x65, 0x50,
            0xF6, 0x6D, 0x67, 0xD7, 0xEF, 0xBD, 0x7C, 0xCB,
            0x8A, 0xC1, 0x1A, 0x54, 0xFC, 0x3B, 0x8B, 0x3A,
            0x0E, 0xE5, 0xEF, 0x27, 0x4A, 0x73, 0x7E, 0x0A,
            0x2E, 0x2E, 0x9D, 0xAF, 0x6C, 0x03, 0xF2, 0x91,
            0xC4, 0xFA, 0x73, 0xFD, 0x6B, 0xA0, 0x07, 0xD4,
            0x75, 0x5B, 0x6F, 0x2E, 0x8B, 0x68, 0x4C, 0xD1,
        ];

        /// <summary>
        /// Expected output value for KeyX0x1B
        /// </summary>
        private static readonly byte[] ExpectedKeyX0x1B =
        [
            0x0A, 0xE4, 0x79, 0x02, 0x1B, 0xFA, 0x25, 0x4B,
            0x2D, 0x92, 0x4F, 0xA8, 0x41, 0x59, 0xCE, 0x10,
            0x09, 0xE6, 0x08, 0x61, 0x23, 0xC7, 0xD2, 0x30,
            0x84, 0x37, 0xD5, 0x49, 0x42, 0x94, 0xB2, 0x70,
            0x6A, 0xF3, 0x75, 0xB0, 0x1F, 0x4F, 0xA1, 0xCE,
            0x03, 0xA2, 0x6A, 0x19, 0x5D, 0x32, 0x0D, 0xB5,
            0x79, 0xCD, 0xFD, 0xF0, 0xDE, 0x49, 0x26, 0x2D,
            0x29, 0x36, 0x30, 0x69, 0x8B, 0x45, 0xE1, 0xFC,
        ];

        /// <summary>
        /// Expected output value for DevKeyX0x1B
        /// </summary>
        private static readonly byte[] ExpectedDevKeyX0x1B =
        [
            0x16, 0x4F, 0xD9, 0x58, 0xC9, 0x20, 0xB3, 0xED,
            0xC4, 0xEB, 0x57, 0x39, 0x10, 0xEF, 0xA8, 0xCC,
            0xE5, 0x49, 0xBF, 0x52, 0x10, 0xA9, 0xCC, 0xE1,
            0x65, 0x3B, 0x2D, 0x51, 0x45, 0xFB, 0x60, 0x52,
            0x3E, 0x29, 0xEB, 0xEB, 0x3F, 0xF2, 0x76, 0x08,
            0x00, 0x05, 0x7F, 0x64, 0x29, 0x4A, 0x17, 0x22,
            0x56, 0x7F, 0x49, 0x94, 0x1A, 0x8C, 0x56, 0x35,
            0x38, 0xBE, 0xA4, 0x2E, 0x58, 0xD3, 0x81, 0x8C,
        ];

        /// <summary>
        /// Expected output value for KeyX0x25
        /// </summary>
        private static readonly byte[] ExpectedKeyX0x25 =
        [
            0x37, 0xBC, 0x73, 0xD6, 0xEE, 0x73, 0xE0, 0x94,
            0x42, 0x84, 0x74, 0xE5, 0xD8, 0xFB, 0x5F, 0x65,
            0xF4, 0xCF, 0x2E, 0xC1, 0x43, 0x48, 0x6C, 0xAA,
            0xC8, 0xF9, 0x96, 0xE6, 0x33, 0xDD, 0xE7, 0xBF,
            0xD2, 0x21, 0x89, 0x39, 0x13, 0xD1, 0xEC, 0xCA,
            0x1D, 0x5D, 0x1F, 0x77, 0x95, 0xD2, 0x8B, 0x27,
            0x92, 0x79, 0xC5, 0x1D, 0x72, 0xA7, 0x28, 0x57,
            0x41, 0x0E, 0x46, 0xB8, 0x80, 0x7B, 0x7C, 0x0D,
        ];

        /// <summary>
        /// Expected output value for DevKeyX0x25
        /// </summary>
        private static readonly byte[] ExpectedDevKeyX0x25 =
        [
            0x71, 0x65, 0x30, 0xF2, 0x68, 0xEC, 0x65, 0x0A,
            0x8C, 0x9E, 0xC5, 0x5A, 0xFA, 0x37, 0x8E, 0xDA,
            0x7B, 0x58, 0x3B, 0x66, 0x7C, 0x9D, 0x16, 0xD9,
            0x2D, 0x8F, 0xCF, 0x04, 0x66, 0x7F, 0x27, 0x41,
            0xBF, 0x5F, 0x1E, 0x11, 0x4C, 0xD6, 0xB9, 0x0A,
            0xC5, 0x42, 0xCF, 0x2B, 0x87, 0x6B, 0xD4, 0x72,
            0x4D, 0x9C, 0x29, 0x2E, 0xF8, 0xB0, 0x6F, 0x22,
            0x35, 0x5B, 0x96, 0x83, 0xD1, 0xE4, 0x5E, 0xDB,
        ];

        /// <summary>
        /// Expected output value for KeyX0x2C
        /// </summary>
        private static readonly byte[] ExpectedKeyX0x2C =
        [
            0xAE, 0x44, 0x20, 0xDB, 0xA5, 0x96, 0xDC, 0xF3,
            0xD8, 0x23, 0x9E, 0x3C, 0x44, 0x73, 0x3D, 0xCD,
            0x07, 0xD5, 0xF8, 0xD0, 0xC6, 0xB3, 0x5A, 0x80,
            0xB5, 0x5A, 0x55, 0x30, 0x5D, 0x4A, 0xBE, 0x61,
            0xBF, 0xEF, 0x64, 0x17, 0x28, 0xD6, 0x26, 0x52,
            0x42, 0x4D, 0x8F, 0x1C, 0xBC, 0x63, 0xD3, 0x91,
            0x7D, 0xA6, 0x4F, 0xAF, 0x26, 0x38, 0x60, 0xEE,
            0x79, 0x92, 0x2F, 0xD8, 0xCA, 0x4E, 0xE7, 0xEC,
        ];

        /// <summary>
        /// Expected output value for DevKeyX0x2C
        /// </summary>
        private static readonly byte[] ExpectedDevKeyX0x2C =
        [
            0x5F, 0x73, 0xD5, 0x9A, 0x67, 0xFF, 0x8C, 0x12,
            0x31, 0x58, 0x0B, 0x58, 0x46, 0xFE, 0x05, 0x16,
            0x92, 0xE4, 0x84, 0x06, 0x18, 0x9B, 0x58, 0x91,
            0xE7, 0xF8, 0xCD, 0xA9, 0x95, 0xAC, 0x07, 0xCD,
            0x43, 0x20, 0x7A, 0x8C, 0xCC, 0xAB, 0x48, 0x50,
            0x29, 0x2F, 0x96, 0x73, 0xB0, 0xD9, 0xE5, 0xCB,
            0xE6, 0x9A, 0x0D, 0xF7, 0xD0, 0x1E, 0xC2, 0xEC,
            0xC1, 0xE2, 0x8E, 0xEE, 0x89, 0xB9, 0xB1, 0x97,
        ];

        #endregion

        /// <summary>
        /// Setup all of the necessary constants
        /// </summary>
        /// <param name="keyfile">Path to the keyfile</param>
        public DecryptArgs(string? config)
        {
            if (config is null || !File.Exists(config))
            {
                IsReady = false;
                return;
            }

            // Try to read the configuration file
            var configObj = Configuration.Create(config);
            if (configObj is null)
            {
                IsReady = false;
                return;
            }

            // Set the fields from the configuration
            NitroEncryptionData = configObj.NitroEncryptionData.FromHexString() ?? [];
            AESHardwareConstant = configObj.AESHardwareConstant.FromHexString() ?? [];
            KeyX0x18 = configObj.KeyX0x18.FromHexString() ?? [];
            KeyX0x1B = configObj.KeyX0x1B.FromHexString() ?? [];
            KeyX0x25 = configObj.KeyX0x25.FromHexString() ?? [];
            KeyX0x2C = configObj.KeyX0x2C.FromHexString() ?? [];
            DevKeyX0x18 = configObj.DevKeyX0x18.FromHexString() ?? [];
            DevKeyX0x1B = configObj.DevKeyX0x1B.FromHexString() ?? [];
            DevKeyX0x25 = configObj.DevKeyX0x25.FromHexString() ?? [];
            DevKeyX0x2C = configObj.DevKeyX0x2C.FromHexString() ?? [];

            IsReady = true;
            ValidateKeys();
        }

        /// <summary>
        /// Validate that all keys provided are going to be valid
        /// </summary>
        /// <remarks>Does not know what the keys are, just the result</remarks>
        private void ValidateKeys()
        {
            // NitroEncryptionData
            if (NitroEncryptionData.Length > 0)
            {
                byte[]? actual = HashTool.GetByteArrayHashArray(NitroEncryptionData, HashType.SHA512);
                if (actual is null || !actual.EqualsExactly(ExpectedNitroSha512Hash))
                {
                    Console.WriteLine($"NitroEncryptionData invalid value, disabling...");
                    NitroEncryptionData = [];
                }
            }

            // KeyX0x18
            if (KeyX0x18.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(KeyX0x18, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedKeyX0x18))
                {
                    Console.WriteLine($"KeyX0x18 invalid value, disabling...");
                    KeyX0x18 = [];
                }
            }

            // DevKeyX0x18
            if (DevKeyX0x18.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(DevKeyX0x18, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedDevKeyX0x18))
                {
                    Console.WriteLine($"DevKeyX0x18 invalid value, disabling...");
                    DevKeyX0x18 = [];
                }
            }

            // KeyX0x1B
            if (KeyX0x1B.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(KeyX0x1B, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedKeyX0x1B))
                {
                    Console.WriteLine($"KeyX0x1B invalid value, disabling...");
                    KeyX0x1B = [];
                }
            }

            // DevKeyX0x1B
            if (DevKeyX0x1B.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(DevKeyX0x1B, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedDevKeyX0x1B))
                {
                    Console.WriteLine($"DevKeyX0x1B invalid value, disabling...");
                    DevKeyX0x1B = [];
                }
            }

            // KeyX0x25
            if (KeyX0x25.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(KeyX0x25, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedKeyX0x25))
                {
                    Console.WriteLine($"KeyX0x25 invalid value, disabling...");
                    KeyX0x25 = [];
                }
            }

            // DevKeyX0x25
            if (DevKeyX0x25.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(DevKeyX0x25, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedDevKeyX0x25))
                {
                    Console.WriteLine($"DevKeyX0x25 invalid value, disabling...");
                    DevKeyX0x25 = [];
                }
            }

            // KeyX0x2C
            if (KeyX0x2C.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(KeyX0x2C, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedKeyX0x2C))
                {
                    Console.WriteLine($"KeyX0x2C invalid value, disabling...");
                    KeyX0x2C = [];
                }
            }

            // DevKeyX0x2C
            if (DevKeyX0x2C.Length > 0)
            {
                var cipher = AESCTR.CreateEncryptionCipher(DevKeyX0x2C, TestIV);
                byte[] actual = cipher.ProcessBytes(TestPattern);
                if (!actual.EqualsExactly(ExpectedDevKeyX0x2C))
                {
                    Console.WriteLine($"DevKeyX0x2C invalid value, disabling...");
                    DevKeyX0x2C = [];
                }
            }
        }
    }
}