img2ffu/Img2Ffu.Library/Reader/Data/Store.cs

/*
 * Copyright (c) Gustave Monce and Contributors
 * 
 * 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.
 */
using Img2Ffu.Reader.Enums;
using Img2Ffu.Reader.Structs;
using System.Text;

namespace Img2Ffu.Reader.Data
{
    public class Store
    {
        public StoreHeader StoreHeader;
        public uint CompressionAlgorithm;
        public StoreHeaderV2 StoreHeaderV2;
        public string DevicePath = ""; // Device path has no NUL at then end (V2 only)
        public readonly List<ValidationDescriptor> ValidationDescriptor = [];
        public readonly List<WriteDescriptor> WriteDescriptors = [];
        public readonly List<string> PlatformIDs = [];
        public byte[] Padding = [];
        public readonly FFUVersion FFUVersion;

        public Store(Stream stream)
        {
            StoreHeader = stream.ReadStructure<StoreHeader>();

            int lastFinding = 0;
            for (int i = 0; i < StoreHeader.PlatformId.Length; i++)
            {
                if (StoreHeader.PlatformId[i] == '\0')
                {
                    if (i == lastFinding)
                    {
                        break;
                    }

                    ASCIIEncoding asciiEncoding = new();
                    string PlatformID = asciiEncoding.GetString(StoreHeader.PlatformId[lastFinding..i]);
                    PlatformIDs.Add(PlatformID);
                    lastFinding = i + 1;
                }
            }

            FFUVersion = GetFFUVersion();

            switch (FFUVersion)
            {
                case FFUVersion.V2:
                    {
                        StoreHeaderV2 = stream.ReadStructure<StoreHeaderV2>();
                        Span<byte> stringBytes = new byte[StoreHeaderV2.DevicePathLength * 2];
                        _ = stream.Read(stringBytes);
                        UnicodeEncoding unicodeEncoding = new();
                        DevicePath = unicodeEncoding.GetString(stringBytes);
                        break;
                    }
                case FFUVersion.V1_COMPRESSED:
                    {
                        using BinaryReader binaryReader = new(stream, Encoding.ASCII, true);
                        CompressionAlgorithm = binaryReader.ReadUInt32();
                        break;
                    }
            }

            for (uint i = 0; i < StoreHeader.ValidateDescriptorCount; i++)
            {
                ValidationDescriptor.Add(new ValidationDescriptor(stream));
            }

            for (uint i = 0; i < StoreHeader.WriteDescriptorCount; i++)
            {
                WriteDescriptors.Add(new WriteDescriptor(stream, FFUVersion));
            }

            long Position = stream.Position;
            if (Position % StoreHeader.BlockSize > 0)
            {
                long paddingSize = StoreHeader.BlockSize - (Position % StoreHeader.BlockSize);
                Padding = new byte[paddingSize];
                _ = stream.Read(Padding);
            }
        }

        public override string ToString()
        {
            return $"{{StoreHeader: {StoreHeader}, StoreHeaderV2: {StoreHeaderV2}, DevicePath: {DevicePath}}}";
        }

        private FFUVersion GetFFUVersion()
        {
            return (StoreHeader.MajorVersion, StoreHeader.FullFlashMajorVersion) switch
            {
                (1, 2) => FFUVersion.V1,
                (1, 3) => FFUVersion.V1_COMPRESSED,
                (2, 2) => FFUVersion.V2,
                _ => throw new InvalidDataException($"Unsupported FFU Store Format! MajorVersion: {StoreHeader.MajorVersion} FullFlashMajorVersion: {StoreHeader.FullFlashMajorVersion}"),
            };
        }
    }
}