Implement model, reader, wrapper for valve SKU sis files.

SabreTools.Serialization.Test/Readers/SkuSisTests.cs

@@ -0,0 +1,73 @@
+using System.IO;
+using System.Linq;
+using SabreTools.Serialization.Readers;
+using Xunit;
+
+namespace SabreTools.Serialization.Test.Readers
+{
+    public class SkuSisTests
+    {
+        [Fact]
+        public void NullArray_Null()
+        {
+            byte[]? data = null;
+            int offset = 0;
+            var deserializer = new SkuSis();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyArray_Null()
+        {
+            byte[]? data = [];
+            int offset = 0;
+            var deserializer = new SkuSis();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidArray_Null()
+        {
+            byte[]? data = [.. Enumerable.Repeat<byte>(0xFF, 1024)];
+            int offset = 0;
+            var deserializer = new SkuSis();
+
+            var actual = deserializer.Deserialize(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void NullStream_Null()
+        {
+            Stream? data = null;
+            var deserializer = new SkuSis();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyStream_Null()
+        {
+            Stream? data = new MemoryStream([]);
+            var deserializer = new SkuSis();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidStream_Null()
+        {
+            Stream? data = new MemoryStream([.. Enumerable.Repeat<byte>(0xFF, 1024)]);
+            var deserializer = new SkuSis();
+
+            var actual = deserializer.Deserialize(data);
+            Assert.Null(actual);
+        }
+    }
+}

SabreTools.Serialization.Test/Wrappers/SkuSisTests.cs

@@ -0,0 +1,61 @@
+using System.IO;
+using System.Linq;
+using SabreTools.Serialization.Wrappers;
+using Xunit;
+
+namespace SabreTools.Serialization.Test.Wrappers
+{
+    public class SkuSisTests
+    {
+        [Fact]
+        public void NullArray_Null()
+        {
+            byte[]? data = null;
+            int offset = 0;
+            var actual = SkuSis.Create(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyArray_Null()
+        {
+            byte[]? data = [];
+            int offset = 0;
+            var actual = SkuSis.Create(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidArray_Null()
+        {
+            byte[]? data = [.. Enumerable.Repeat<byte>(0xFF, 1024)];
+            int offset = 0;
+            var actual = SkuSis.Create(data, offset);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void NullStream_Null()
+        {
+            Stream? data = null;
+            var actual = SkuSis.Create(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void EmptyStream_Null()
+        {
+            Stream? data = new MemoryStream([]);
+            var actual = SkuSis.Create(data);
+            Assert.Null(actual);
+        }
+
+        [Fact]
+        public void InvalidStream_Null()
+        {
+            Stream? data = new MemoryStream([.. Enumerable.Repeat<byte>(0xFF, 1024)]);
+            var actual = SkuSis.Create(data);
+            Assert.Null(actual);
+        }
+    }
+}

SabreTools.Serialization/Models/VDF/Constants.cs

@@ -0,0 +1,19 @@
+namespace SabreTools.Data.Models.VDF
+{
+    public static class Constants
+    {
+        /// <summary>
+        /// Top-level item (and thus also first 5 bytes) of Steam2 (sis/sim/sid) retail installers
+        /// </summary>
+        public static readonly byte[] Steam2SisSignatureBytes = [0x22, 0x53, 0x4B, 0x55, 0x22]; // "SKU"
+
+        public static readonly string Steam2SisSignatureString = "\"SKU\"";
+
+        /// <summary>
+        /// Top-level item (and thus also first 5 bytes) of Steam3 (sis/csm/csd) retail installers
+        /// </summary>
+        public static readonly byte[] Steam3SisSignatureBytes = [0x22, 0x73, 0x6B, 0x75, 0x22]; // "sku"
+
+        public static readonly string Steam3SisSignatureString = "\"sku\"";
+    }
+}

SabreTools.Serialization/Models/VDF/File.cs

@@ -0,0 +1,25 @@
+using Newtonsoft.Json.Linq;
+
+namespace SabreTools.Data.Models.VDF
+{
+    /// <summary>
+    /// Valve Data File
+    /// </summary>
+    /// <remarks>
+    /// Valve's json-like format, used for a variety of things across Steam.
+    /// </remarks>
+    /// <see href="https://github.com/ValveResourceFormat/ValveKeyValue"/>
+    /// <see href="https://developer.valvesoftware.com/wiki/VDF"/>
+    public class File
+    {   
+        /// <summary>
+        /// A byte array representing the signature/top level item.
+        /// </summary>
+        public byte[]? Signature { get; set; }
+
+        /// <summary>
+        /// A JSON Object representing the VDF structure.
+        /// </summary>
+        public JObject? VDFObject { get; set; }
+    }
+}

SabreTools.Serialization/Readers/SkuSis.cs

@@ -0,0 +1,114 @@
+using System;
+using System.IO;
+using SabreTools.IO.Extensions;
+using File = SabreTools.Data.Models.VDF.File;
+using static SabreTools.Data.Models.VDF.Constants;
+using System.Text;
+using Newtonsoft.Json.Linq;
+
+namespace SabreTools.Serialization.Readers
+{
+    /// <remarks>
+    /// The VDF file format was used for a very wide scope of functions on steam. At the moment, VDF file support is 
+    /// only needed when it comes to parsing retail sku sis files, so the current parser is only aimed at supporting
+    /// these files, as they're overall very consistent, and trying to test every usage of VDF files would be extremely
+    /// time-consuming for little benefit. If parsing other usages of VDF files ever becomes necessary, this should be
+    /// replaced with a general-purpose VDF parser.
+    /// Most observations about sku sis files described here probably also apply to VDF files.
+    /// </remarks>
+    public class SkuSis : BaseBinaryReader<File>
+    {
+        /// <inheritdoc/>
+        public override File? Deserialize(Stream? data)
+        {
+            // If the data is invalid
+            if (data == null || !data.CanRead)
+                return null;
+
+            try
+            {
+                // Cache the current offset
+                long initialOffset = data.Position;
+
+                // Check if file contains the top level sku value, otherwise return null
+                var signatureBytes = data.ReadBytes(5);
+                if (!signatureBytes.EqualsExactly(Steam2SisSignatureBytes)
+                    && !signatureBytes.EqualsExactly(Steam3SisSignatureBytes))
+                    return null;
+
+                data.SeekIfPossible(initialOffset, SeekOrigin.Begin);
+
+                var skuSis = ParseSkuSis(data);
+                if (skuSis == null)
+                    return null;
+
+                if (skuSis.VDFObject == null)
+                    return null;
+
+                skuSis.Signature = signatureBytes;
+
+                return skuSis;
+            }
+            catch
+            {
+                // Ignore the actual error
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Parse a Stream into a Header
+        /// </summary>
+        /// <param name="data">Stream to parse</param>
+        /// <returns>Filled Header on success, null on error</returns>
+        public static File? ParseSkuSis(Stream data)
+        {
+            var obj = new File();
+
+            string json = "{\n"; // Sku sis files have no surrounding curly braces, which json doesn't allow
+            string delimiter = "\"\t\t\""; // KVPs are always quoted, and are delimited by two tabs
+            string? line;
+            var reader = new StreamReader(data, Encoding.ASCII);
+
+            while (!reader.EndOfStream)
+            {
+                line = reader.ReadLine();
+                if (line == null)
+                    continue;
+
+                // Curly braces are always on their own lines
+                if (line.Contains("{"))
+                {
+                    json += "{\n";
+                    continue;
+                }
+                else if (line.Contains("}"))
+                {
+                    json += line;
+                    json += ",\n";
+                    continue;
+                }
+
+                int index = line.IndexOf(delimiter, StringComparison.Ordinal);
+
+                // If the delimiter isn't found, this is the start of an object with multiple KVPs and the next line 
+                // will be an opening curly brace line.
+                if (index <= -1) 
+                {
+                    json += line;
+                    json += ": ";
+                }
+                else // If the delimiter is found, it's just a normal KVP
+                {
+                    json += line.Replace(delimiter, "\": \"");
+                    json += ",\n";
+                }
+            }
+
+            json += "\n}";
+            obj.VDFObject = JObject.Parse(json);
+
+            return obj;
+        }
+    }
+}

SabreTools.Serialization/WrapperFactory.cs

@@ -53,6 +53,7 @@ public static class WrapperFactory
                 WrapperType.SecuROMDFA => SecuROMDFA.Create(data),
                 WrapperType.SevenZip => SevenZip.Create(data),
                 WrapperType.Skeleton => Skeleton.Create(data),
+                WrapperType.SkuSis => SkuSis.Create(data),
                 WrapperType.SFFS => SFFS.Create(data),
                 WrapperType.SGA => SGA.Create(data),
                 WrapperType.TapeArchive => TapeArchive.Create(data),
@@ -671,6 +672,15 @@ public static WrapperType GetFileType(byte[]? magic, string? extension)
                 return WrapperType.SFFS;
 
             #endregion
+
+            #region SkuSis
+
+            // TODO: add description
+            if (magic.StartsWith(Data.Models.VDF.Constants.Steam2SisSignatureBytes) 
+                || magic.StartsWith(Data.Models.VDF.Constants.Steam3SisSignatureBytes))
+                return WrapperType.SkuSis;
+
+            #endregion
 
             #region SGA