Implement NcaReader from FS 17.0.0

src/LibHac/Fs/QueryRangeInfo.cs

@@ -19,6 +19,7 @@ public struct QueryRangeInfo
         AesCtrKeyType |= other.AesCtrKeyType;
         SpeedEmulationType |= other.SpeedEmulationType;
     }
+}
 
 [Flags]
 public enum AesCtrKeyTypeFlag
@@ -27,4 +28,3 @@ public struct QueryRangeInfo
     InternalKeyForHardwareAes = 1 << 1,
     ExternalKeyForHardwareAes = 1 << 2
 }
-}

src/LibHac/FsSystem/AesCtrCounterExtendedStorage.cs

@@ -404,8 +404,8 @@ public class AesCtrCounterExtendedStorage : IStorage
                 Unsafe.SkipInit(out QueryRangeInfo info);
                 info.Clear();
                 info.AesCtrKeyType = (int)(_decryptor.Get.HasExternalDecryptionKey()
-                    ? QueryRangeInfo.AesCtrKeyTypeFlag.ExternalKeyForHardwareAes
+                    ? AesCtrKeyTypeFlag.ExternalKeyForHardwareAes
-                    : QueryRangeInfo.AesCtrKeyTypeFlag.InternalKeyForHardwareAes);
+                    : AesCtrKeyTypeFlag.InternalKeyForHardwareAes);
 
                 outInfo.Merge(in info);
 

src/LibHac/FsSystem/AesCtrStorage.cs

@@ -215,7 +215,7 @@ public class AesCtrStorage : IStorage
 
                 Unsafe.SkipInit(out QueryRangeInfo info);
                 info.Clear();
-                info.AesCtrKeyType = (int)QueryRangeInfo.AesCtrKeyTypeFlag.InternalKeyForSoftwareAes;
+                info.AesCtrKeyType = (int)AesCtrKeyTypeFlag.InternalKeyForSoftwareAes;
 
                 outInfo.Merge(in info);
 

src/LibHac/FsSystem/BucketTree.cs

@@ -128,7 +128,7 @@ file struct StorageNode
 /// <remarks>Based on nnSdk 16.2.0 (FS 16.0.0)</remarks>
 public partial class BucketTree : IDisposable
 {
-    private const uint Signature = 0x52544B42; // BKTR
+    public const uint Signature = 0x52544B42; // BKTR
     private const int MaxVersion = 1;
 
     private const int NodeSizeMin = 1024;

src/LibHac/FsSystem/CompressionCommon.cs

@@ -10,7 +10,14 @@ public enum CompressionType : byte
     Unknown = 4
 }
 
-public delegate Result DecompressorFunction(Span<byte> destination, ReadOnlySpan<byte> source);
+public ref struct DecompressionTask
+{
+    public Span<byte> Destination;
+    public ReadOnlySpan<byte> Source;
+}
+
+public delegate Result DecompressorFunction(DecompressionTask task);
+
 public delegate DecompressorFunction GetDecompressorFunction(CompressionType compressionType);
 
 public static class CompressionTypeUtility

src/LibHac/FsSystem/IAesCtrDecryptor.cs

@@ -0,0 +1,13 @@
+using System;
+using LibHac.Fs;
+using LibHac.Spl;
+
+namespace LibHac.FsSystem;
+
+public interface IAesCtrDecryptor : IDisposable
+{
+    Result Decrypt(Span<byte> destination, ReadOnlySpan<byte> iv, ReadOnlySpan<byte> source);
+    void PrioritizeSw();
+    void SetExternalKeySource(in Spl.AccessKey keySource);
+    AesCtrKeyTypeFlag GetKeyTypeFlag();
+}

src/LibHac/FsSystem/NcaHeader.cs

@@ -1,12 +1,51 @@
 using System;
+using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using LibHac.Common;
 using LibHac.Common.FixedArrays;
+using LibHac.Crypto;
 using LibHac.Fs;
+using LibHac.Util;
+using static LibHac.FsSystem.Anonymous;
 
 namespace LibHac.FsSystem;
 
+file static class Anonymous
+{
+    public static bool IsZero<T>(ReadOnlySpan<T> value) where T : unmanaged
+    {
+        ReadOnlySpan<byte> valueBytes = MemoryMarshal.Cast<T, byte>(value);
+        Span<byte> zero = stackalloc byte[valueBytes.Length];
+        zero.Clear();
+
+        return CryptoUtil.IsSameBytes(valueBytes, zero, valueBytes.Length);
+    }
+
+    public static bool IsZero<T>(in T value) where T : unmanaged
+    {
+        ReadOnlySpan<byte> valueBytes = SpanHelpers.AsReadOnlyByteSpan(in value);
+        Span<byte> zero = stackalloc byte[Unsafe.SizeOf<T>()];
+        zero.Clear();
+
+        return CryptoUtil.IsSameBytes(valueBytes, zero, Unsafe.SizeOf<T>());
+    }
+
+    public static bool IsZero<T>(in T value, int startOffset) where T : unmanaged
+    {
+        ReadOnlySpan<byte> valueBytes = SpanHelpers.AsReadOnlyByteSpan(in value).Slice(startOffset);
+        Span<byte> zero = stackalloc byte[Unsafe.SizeOf<T>() - startOffset];
+        zero.Clear();
+
+        return CryptoUtil.IsSameBytes(valueBytes, zero, Unsafe.SizeOf<T>() - startOffset);
+    }
+
+    public static bool IsIncluded<T>(T value, T min, T max) where T : IComparisonOperators<T, T, bool>
+    {
+        return min <= value && value <= max;
+    }
+}
+
 /// <summary>
 /// The structure used as the header for an NCA file.
 /// </summary>
@@ -96,6 +135,76 @@ public struct NcaHeader
     public static uint ByteToSector(ulong byteIndex) => (uint)(byteIndex >> SectorShift);
 
     public readonly byte GetProperKeyGeneration() => Math.Max(KeyGeneration1, KeyGeneration2);
+
+    public readonly Result Verify()
+    {
+        const uint magicBodyMask = 0xFFFFFF;
+        const uint magicVersionMask = 0xFF000000;
+        const uint magicBodyValue = 0x41434E; // NCA
+        const uint magicVersionMax = 0x33000000; // \0\0\03
+
+        if ((Magic & magicBodyMask) != magicBodyValue || (Magic & magicVersionMask) > magicVersionMax)
+            return ResultFs.InvalidNcaHeader.Log();
+
+        if (!IsIncluded((int)DistributionTypeValue, (int)DistributionType.Download, (int)DistributionType.GameCard))
+            return ResultFs.InvalidNcaHeader.Log();
+
+        if (!IsIncluded((int)ContentTypeValue, (int)ContentType.Program, (int)ContentType.PublicData))
+            return ResultFs.InvalidNcaHeader.Log();
+
+        if (KeyAreaEncryptionKeyIndex >= NcaCryptoConfiguration.KeyAreaEncryptionKeyIndexCount &&
+            KeyAreaEncryptionKeyIndex != NcaCryptoConfiguration.KeyAreaEncryptionKeyIndexZeroKey)
+        {
+            return ResultFs.InvalidNcaHeader.Log();
+        }
+
+        if (ProgramId == 0)
+            return ResultFs.InvalidNcaHeader.Log();
+
+        if (SdkAddonVersion == 0)
+            return ResultFs.InvalidNcaHeader.Log();
+
+        if (!IsZero(in Reserved222))
+            return ResultFs.InvalidNcaHeader.Log();
+
+        if (!IsZero(in Reserved224))
+            return ResultFs.InvalidNcaHeader.Log();
+
+        long es = long.MaxValue;
+
+        for (int i = 0; i < FsCountMax; i++)
+        {
+            if (FsInfos[i].StartSector != 0 || FsInfos[i].EndSector != 0)
+            {
+                if (es == long.MaxValue)
+                    es = FsInfos[i].EndSector;
+
+                if (es < FsInfos[i].EndSector || FsInfos[i].StartSector >= FsInfos[i].EndSector)
+                    return ResultFs.InvalidNcaHeader.Log();
+
+                es = FsInfos[i].StartSector;
+
+                if (FsInfos[i].HashSectors != ByteToSector(0x200))
+                    return ResultFs.InvalidNcaHeader.Log();
+            }
+            else if (FsInfos[i].HashSectors != 0)
+            {
+                return ResultFs.InvalidNcaHeader.Log();
+            }
+
+            if (FsInfos[i].Reserved != 0)
+                return ResultFs.InvalidNcaHeader.Log();
+        }
+
+        const int offset = (int)DecryptionKey.Count * Aes.KeySize128;
+        if (!IsZero(EncryptedKeys[..][offset..]))
+            return ResultFs.InvalidNcaHeader.Log();
+
+        if (!IsZero(EncryptedKeys[offset..]))
+            return ResultFs.InvalidNcaHeader.Log();
+
+        return Result.Success;
+    }
 }
 
 public struct NcaPatchInfo
@@ -107,8 +216,15 @@ public struct NcaPatchInfo
     public long AesCtrExSize;
     public Array16<byte> AesCtrExHeader;
 
-    public readonly bool HasIndirectTable() => IndirectSize != 0;
+    public readonly bool HasIndirectTable()
-    public readonly bool HasAesCtrExTable() => AesCtrExSize != 0;
+    {
+        return Unsafe.As<Array16<byte>, uint>(ref Unsafe.AsRef(in IndirectHeader)) == BucketTree.Signature;
+    }
+
+    public readonly bool HasAesCtrExTable()
+    {
+        return Unsafe.As<Array16<byte>, uint>(ref Unsafe.AsRef(in AesCtrExHeader)) == BucketTree.Signature;
+    }
 }
 
 public struct NcaSparseInfo
@@ -129,6 +245,11 @@ public struct NcaSparseInfo
         sparseUpperIv.Generation = GetGeneration();
         return sparseUpperIv;
     }
+
+    public readonly bool HasSparseTable()
+    {
+        return Unsafe.As<Array16<byte>, uint>(ref Unsafe.AsRef(in MetaHeader)) == BucketTree.Signature;
+    }
 }
 
 public struct NcaCompressionInfo
@@ -219,7 +340,8 @@ public struct NcaFsHeader
     public enum MetaDataHashType : byte
     {
         None = 0,
-        HierarchicalIntegrity = 1
+        HierarchicalIntegrity = 1,
+        HierarchicalIntegritySha3 = 2
     }
 
     public struct Region
@@ -240,10 +362,45 @@ public struct NcaFsHeader
             public int BlockSize;
             public int LayerCount;
             public Array5<Region> LayerRegions;
+
+            public readonly Result Verify()
+            {
+                if (IsZero(in MasterHash))
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                if (BlockSize <= 0 || !BitUtil.IsPowerOfTwo(BlockSize))
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                if (LayerCount != 2)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                long currentOffset = 0;
+
+                for (int i = 0; i < LayerCount; i++)
+                {
+                    if (currentOffset > LayerRegions[i].Offset)
+                        return ResultFs.InvalidNcaFsHeader.Log();
+
+                    if (LayerRegions[i].Size <= 0)
+                        return ResultFs.InvalidNcaFsHeader.Log();
+
+                    currentOffset = LayerRegions[i].Offset + LayerRegions[i].Size;
+                }
+
+                for (int i = LayerCount; i < 5; i++)
+                {
+                    if (!IsZero(in LayerRegions[i]))
+                        return ResultFs.InvalidNcaFsHeader.Log();
+                }
+
+                return Result.Success;
+            }
         }
 
         public struct IntegrityMetaInfo
         {
+            public const int HashSize = Sha256Generator.HashSize;
+
             public uint Magic;
             public uint Version;
             public uint MasterHashSize;
@@ -269,7 +426,192 @@ public struct NcaFsHeader
                     public Array32<byte> Value;
                 }
             }
+
+            public readonly Result Verify()
+            {
+                if (Magic != HierarchicalIntegrityVerificationStorage.IntegrityVerificationStorageMagic)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                if (Version != HierarchicalIntegrityVerificationStorage.IntegrityVerificationStorageVersion)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                if (MasterHashSize != HashSize)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                if (!IsIncluded(LevelHashInfo.MaxLayers, Constants.IntegrityMinLayerCount, Constants.IntegrityMaxLayerCount))
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                long currentOffset = 0;
+
+                for (int i = 0; i < LevelHashInfo.MaxLayers - 1; i++)
+                {
+                    ref readonly InfoLevelHash.HierarchicalIntegrityVerificationLevelInformation layer = ref LevelHashInfo.Layers[i];
+
+                    if (layer.OrderBlock <= 0)
+                        return ResultFs.InvalidNcaFsHeader.Log();
+
+                    if (currentOffset > layer.Offset || !Alignment.IsAligned(layer.Offset.Get(), (ulong)(1 << layer.OrderBlock)))
+                        return ResultFs.InvalidNcaFsHeader.Log();
+
+                    if (layer.Size <= 0)
+                        return ResultFs.InvalidNcaFsHeader.Log();
+
+                    if (!IsZero<byte>(layer.Reserved))
+                        return ResultFs.InvalidNcaFsHeader.Log();
+
+                    currentOffset = layer.Offset + layer.Size;
                 }
+
+                for (int i = LevelHashInfo.MaxLayers - 1; i < 6; i++)
+                {
+                    if (!IsZero(in LevelHashInfo.Layers[i]))
+                        return ResultFs.InvalidNcaFsHeader.Log();
+                }
+
+                return Result.Success;
+            }
+        }
+    }
+
+    public Result Verify()
+    {
+        if (Version != 2)
+            return ResultFs.InvalidNcaFsHeader.Log();
+
+        if (!IsIncluded((int)FsTypeValue, (int)FsType.RomFs, (int)FsType.PartitionFs))
+            return ResultFs.InvalidNcaFsHeader.Log();
+
+        if (!IsIncluded((int)HashTypeValue, (int)HashType.None, (int)HashType.HierarchicalIntegritySha3Hash) || HashTypeValue == HashType.AutoSha3)
+            return ResultFs.InvalidNcaFsHeader.Log();
+
+        if (!IsIncluded((int)EncryptionTypeValue, (int)EncryptionType.None, (int)EncryptionType.AesCtrExSkipLayerHash))
+            return ResultFs.InvalidNcaFsHeader.Log();
+
+        if (!IsIncluded((int)MetaDataHashTypeValue, (int)MetaDataHashType.None, (int)MetaDataHashType.HierarchicalIntegritySha3))
+            return ResultFs.InvalidNcaFsHeader.Log();
+
+        if (!IsZero(in Reserved))
+            return ResultFs.InvalidNcaFsHeader.Log();
+
+        switch (HashTypeValue)
+        {
+            case HashType.HierarchicalSha256Hash:
+            case HashType.HierarchicalSha3256Hash:
+            {
+                Result res = HashDataValue.HierarchicalSha256.Verify();
+                if (res.IsFailure()) return res.Miss();
+
+                if (!IsZero(in HashDataValue, Unsafe.SizeOf<HashData.HierarchicalSha256Data>()))
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                break;
+            }
+            case HashType.HierarchicalIntegrityHash:
+            case HashType.HierarchicalIntegritySha3Hash:
+            {
+                Result res = HashDataValue.IntegrityMeta.Verify();
+                if (res.IsFailure()) return res.Miss();
+
+                if (!IsZero(in HashDataValue, Unsafe.SizeOf<HashData.IntegrityMetaInfo>()))
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                break;
+            }
+            default:
+            {
+                if (!IsZero(in HashDataValue))
+                    return ResultFs.InvalidNcaFsHeader.Log();
+
+                break;
+            }
+        }
+
+        if (EncryptionTypeValue == EncryptionType.AesCtrEx || EncryptionTypeValue == EncryptionType.AesCtrExSkipLayerHash)
+        {
+            if (PatchInfo.IndirectOffset < 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (PatchInfo.IndirectSize <= 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (IsZero(in PatchInfo.IndirectHeader))
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (PatchInfo.AesCtrExOffset < 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (MetaDataHashTypeValue == MetaDataHashType.None)
+            {
+                if (PatchInfo.AesCtrExSize <= 0)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+            }
+            else if (PatchInfo.IndirectOffset == 0)
+            {
+                if (PatchInfo.AesCtrExSize != 0)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+            }
+            else if (PatchInfo.AesCtrExSize <= 0)
+            {
+                return ResultFs.InvalidNcaFsHeader.Log();
+            }
+
+            if (IsZero(in PatchInfo.AesCtrExHeader))
+                return ResultFs.InvalidNcaFsHeader.Log();
+        }
+        else if (EncryptionTypeValue != EncryptionType.None && !IsZero(in PatchInfo))
+        {
+            return ResultFs.InvalidNcaFsHeader.Log();
+        }
+
+        if (EncryptionTypeValue != EncryptionType.AesCtr
+            && EncryptionTypeValue != EncryptionType.AesCtrEx
+            && EncryptionTypeValue != EncryptionType.AesCtrSkipLayerHash
+            && EncryptionTypeValue != EncryptionType.AesCtrExSkipLayerHash
+            && !IsZero(in AesCtrUpperIv))
+        {
+            return ResultFs.InvalidNcaFsHeader.Log();
+        }
+
+        if (SparseInfo.Generation != 0)
+        {
+            if (SparseInfo.MetaOffset < 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (SparseInfo.MetaSize < 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (SparseInfo.PhysicalOffset < 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (!IsZero(SparseInfo.Reserved))
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            var header = SpanHelpers.AsStruct<BucketTree.Header>(SparseInfo.MetaHeader);
+            Result res = header.Verify();
+            if (res.IsFailure()) return res.Miss();
+        }
+        else if (!IsZero(in SparseInfo))
+        {
+            return ResultFs.InvalidNcaFsHeader.Log();
+        }
+
+        if (MetaDataHashTypeValue != MetaDataHashType.None)
+        {
+            if (MetaDataHashDataInfo.Offset <= 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            if (MetaDataHashDataInfo.Size <= 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+        }
+        else if (!IsZero(MetaDataHashDataInfo))
+        {
+            return ResultFs.InvalidNcaFsHeader.Log();
+        }
+
+        if (!IsZero(Padding))
+            return ResultFs.InvalidNcaFsHeader.Log();
+
+        return Result.Success;
     }
 
     public readonly Result GetHashTargetOffset(out long outOffset)

src/LibHac/FsSystem/NcaReader17.cs

@@ -0,0 +1,454 @@
+using System;
+using System.Runtime.CompilerServices;
+using LibHac.Common;
+using LibHac.Crypto;
+using LibHac.Diag;
+using LibHac.Fs;
+using LibHac.Spl;
+
+namespace LibHac.FsSystem;
+
+/// <summary>
+/// Handles reading information from an NCA's header.
+/// </summary>
+/// <remarks>Based on nnSdk 17.5.0 (FS 17.0.0)</remarks>
+public class NcaReader17 : IDisposable
+{
+    private RuntimeNcaHeader _header;
+    private SharedRef<IStorage> _bodyStorage;
+    private SharedRef<IStorage> _headerStorage;
+    private SharedRef<IAesCtrDecryptor> _aesCtrDecryptor;
+    private GetDecompressorFunction _getDecompressorFunc;
+    private IHash256GeneratorFactorySelector _hashGeneratorFactorySelector;
+
+    public NcaReader17(in RuntimeNcaHeader runtimeNcaHeader, ref readonly SharedRef<IStorage> notVerifiedHeaderStorage,
+        ref readonly SharedRef<IStorage> bodyStorage, ref readonly SharedRef<IAesCtrDecryptor> aesCtrDecryptor,
+        in NcaCompressionConfiguration compressionConfig, IHash256GeneratorFactorySelector hashGeneratorFactorySelector)
+    {
+        Assert.SdkRequiresNotNull(in notVerifiedHeaderStorage);
+        Assert.SdkRequiresNotNull(in bodyStorage);
+        Assert.SdkRequiresNotNull(hashGeneratorFactorySelector);
+
+        _header = runtimeNcaHeader;
+
+        _headerStorage = SharedRef<IStorage>.CreateCopy(in notVerifiedHeaderStorage);
+        _bodyStorage = SharedRef<IStorage>.CreateCopy(in bodyStorage);
+        _aesCtrDecryptor = SharedRef<IAesCtrDecryptor>.CreateCopy(in aesCtrDecryptor);
+
+        _getDecompressorFunc = compressionConfig.GetDecompressorFunc;
+        _hashGeneratorFactorySelector = hashGeneratorFactorySelector;
+    }
+
+    public void Dispose()
+    {
+        _bodyStorage.Destroy();
+        _headerStorage.Destroy();
+        _aesCtrDecryptor.Destroy();
+    }
+
+    public Result ReadHeader(out NcaFsHeader outHeader, int index)
+    {
+        UnsafeHelpers.SkipParamInit(out outHeader);
+
+        Assert.SdkRequiresInRange(index, 0, NcaHeader.FsCountMax);
+
+        long offset = _header.FsHeadersOffset + Unsafe.SizeOf<NcaFsHeader>() * (long)index;
+        return _headerStorage.Get.Read(offset, SpanHelpers.AsByteSpan(ref outHeader)).Ret();
+    }
+
+    public Result GetHeaderSign2(Span<byte> outBuffer)
+    {
+        Assert.SdkRequiresGreaterEqual((uint)outBuffer.Length, _header.Header2SignInfo.Size);
+
+        return _headerStorage.Get
+            .Read(_header.Header2SignInfo.Size, outBuffer.Slice(0, (int)_header.Header2SignInfo.Size)).Ret();
+    }
+
+    public void GetHeaderSign2TargetHash(Span<byte> outBuffer)
+    {
+        Assert.SdkRequiresEqual(outBuffer.Length, Unsafe.SizeOf<Hash>());
+
+        _header.Header2SignInfo.Hash.Value[..].CopyTo(outBuffer);
+    }
+
+    public SharedRef<IStorage> GetSharedBodyStorage()
+    {
+        Assert.SdkRequiresNotNull(_bodyStorage);
+
+        return SharedRef<IStorage>.CreateCopy(in _bodyStorage);
+    }
+
+    public NcaHeader.DistributionType GetDistributionType()
+    {
+        return _header.DistributionType;
+    }
+
+    public NcaHeader.ContentType GetContentType()
+    {
+        return _header.ContentType;
+    }
+
+    public byte GetKeyGeneration()
+    {
+        return _header.KeyGeneration;
+    }
+
+    public ulong GetProgramId()
+    {
+        return _header.ProgramId;
+    }
+
+    public void GetRightsId(Span<byte> outBuffer)
+    {
+        Assert.SdkRequiresGreaterEqual(outBuffer.Length, NcaHeader.RightsIdSize);
+
+        _header.RightsId[..].CopyTo(outBuffer);
+    }
+
+    public bool HasFsInfo(int index)
+    {
+        Assert.SdkRequiresInRange(index, 0, NcaHeader.FsCountMax);
+        return _header.FsInfos[index].StartSector != 0 || _header.FsInfos[index].EndSector != 0;
+    }
+
+    public void GetFsHeaderHash(out Hash outHash, int index)
+    {
+        Assert.SdkRequiresInRange(index, 0, NcaHeader.FsCountMax);
+        outHash = _header.FsInfos[index].Hash;
+    }
+
+    public void GetFsInfo(out NcaHeader.FsInfo outFsInfo, int index)
+    {
+        Assert.SdkRequiresInRange(index, 0, NcaHeader.FsCountMax);
+
+        outFsInfo = new NcaHeader.FsInfo
+        {
+            StartSector = _header.FsInfos[index].StartSector,
+            EndSector = _header.FsInfos[index].EndSector,
+            HashSectors = _header.FsInfos[index].HashSectors,
+            Reserved = 0
+        };
+    }
+
+    public ulong GetFsOffset(int index)
+    {
+        Assert.SdkRequiresInRange(index, 0, NcaHeader.FsCountMax);
+
+        return NcaHeader.SectorToByte(_header.FsInfos[index].StartSector);
+    }
+
+    public ulong GetFsEndOffset(int index)
+    {
+        Assert.SdkRequiresInRange(index, 0, NcaHeader.FsCountMax);
+
+        return NcaHeader.SectorToByte(_header.FsInfos[index].EndSector);
+    }
+
+    public ulong GetFsSize(int index)
+    {
+        Assert.SdkRequiresInRange(index, 0, NcaHeader.FsCountMax);
+
+        return NcaHeader.SectorToByte(_header.FsInfos[index].EndSector - _header.FsInfos[index].StartSector);
+    }
+
+    public void PrioritizeSwAes()
+    {
+        if (_aesCtrDecryptor.HasValue)
+        {
+            _aesCtrDecryptor.Get.PrioritizeSw();
+        }
+    }
+
+    public void SetExternalDecryptionKey(in AccessKey keySource)
+    {
+        if (_aesCtrDecryptor.HasValue)
+        {
+            _aesCtrDecryptor.Get.SetExternalKeySource(in keySource);
+        }
+    }
+
+    public RuntimeNcaHeader GetHeader()
+    {
+        return _header;
+    }
+
+    public SharedRef<IAesCtrDecryptor> GetDecryptor()
+    {
+        return SharedRef<IAesCtrDecryptor>.CreateCopy(in _aesCtrDecryptor);
+    }
+
+    public GetDecompressorFunction GetDecompressor()
+    {
+        Assert.SdkRequiresNotNull(_getDecompressorFunc);
+        return _getDecompressorFunc;
+    }
+
+    public IHash256GeneratorFactorySelector GetHashGeneratorFactorySelector()
+    {
+        Assert.SdkRequiresNotNull(_hashGeneratorFactorySelector);
+        return _hashGeneratorFactorySelector;
+    }
+
+    public Result Verify()
+    {
+        Assert.SdkRequiresNotNull(_bodyStorage);
+
+        for (int fsIndex = 0; fsIndex < NcaHeader.FsCountMax; fsIndex++)
+        {
+            var reader = new NcaFsHeaderReader17();
+            if (HasFsInfo(fsIndex))
+            {
+                Result res = reader.Initialize(this, fsIndex);
+                if (res.IsFailure()) return res.Miss();
+
+                res = reader.Verify(_header.ContentType);
+                if (res.IsFailure()) return res.Miss();
+            }
+            else
+            {
+                Result res = ReadHeader(out NcaFsHeader header, fsIndex);
+                if (res.IsFailure()) return res.Miss();
+
+                NcaFsHeader zero = default;
+                if (!CryptoUtil.IsSameBytes(SpanHelpers.AsReadOnlyByteSpan(in header),
+                    SpanHelpers.AsReadOnlyByteSpan(in zero), Unsafe.SizeOf<NcaFsHeader>()))
+                {
+                    return ResultFs.InvalidNcaFsHeader.Log();
+                }
+            }
+        }
+
+        return Result.Success;
+    }
+}
+
+/// <summary>
+/// Handles reading information from the <see cref="NcaFsHeader"/> of a file system inside an NCA file.
+/// </summary>
+/// <remarks>Based on nnSdk 17.5.0 (FS 17.0.0)</remarks>
+public class NcaFsHeaderReader17
+{
+    private NcaFsHeader _header;
+    private int _fsIndex;
+
+    public NcaFsHeaderReader17()
+    {
+        _fsIndex = -1;
+    }
+
+    public bool IsInitialized()
+    {
+        return _fsIndex >= 0;
+    }
+
+    public Result Initialize(NcaReader17 reader, int index)
+    {
+        _fsIndex = -1;
+
+        Result res = reader.ReadHeader(out _header, index);
+        if (res.IsFailure()) return res.Miss();
+
+        Unsafe.SkipInit(out Hash hash);
+        IHash256GeneratorFactory generator = reader.GetHashGeneratorFactorySelector().GetFactory(HashAlgorithmType.Sha2);
+        generator.GenerateHash(hash.Value, SpanHelpers.AsReadOnlyByteSpan(in _header));
+
+        reader.GetFsHeaderHash(out Hash fsHeaderHash, index);
+
+        if (!CryptoUtil.IsSameBytes(fsHeaderHash.Value, hash.Value, Unsafe.SizeOf<Hash>()))
+        {
+            return ResultFs.NcaFsHeaderHashVerificationFailed.Log();
+        }
+
+        _fsIndex = index;
+        return Result.Success;
+    }
+
+    public ref readonly NcaFsHeader.HashData GetHashData()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return ref _header.HashDataValue;
+    }
+
+    public ushort GetVersion()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.Version;
+    }
+
+    public int GetFsIndex()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _fsIndex;
+    }
+
+    public NcaFsHeader.FsType GetFsType()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.FsTypeValue;
+    }
+
+    public NcaFsHeader.HashType GetHashType()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.HashTypeValue;
+    }
+
+    public NcaFsHeader.EncryptionType GetEncryptionType()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.EncryptionTypeValue;
+    }
+
+    public NcaFsHeader.MetaDataHashType GetPatchMetaHashType()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.MetaDataHashTypeValue;
+    }
+
+    public NcaFsHeader.MetaDataHashType GetSparseMetaHashType()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.MetaDataHashTypeValue;
+    }
+
+    public Result GetHashTargetOffset(out long outOffset)
+    {
+        Assert.SdkRequires(IsInitialized());
+
+        Result res = _header.GetHashTargetOffset(out outOffset);
+        if (res.IsFailure()) return res.Miss();
+
+        return Result.Success;
+    }
+
+    public bool IsSkipLayerHashEncryption()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.IsSkipLayerHashEncryption();
+    }
+
+    public ref readonly NcaPatchInfo GetPatchInfo()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return ref _header.PatchInfo;
+    }
+
+    public NcaAesCtrUpperIv GetAesCtrUpperIv()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.AesCtrUpperIv;
+    }
+
+    public bool ExistsSparseLayer()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.SparseInfo.Generation != 0;
+    }
+
+    public ref readonly NcaSparseInfo GetSparseInfo()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return ref _header.SparseInfo;
+    }
+
+    public bool ExistsCompressionLayer()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.CompressionInfo.TableOffset != 0 && _header.CompressionInfo.TableSize != 0;
+    }
+
+    public ref readonly NcaCompressionInfo GetCompressionInfo()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return ref _header.CompressionInfo;
+    }
+
+    public bool ExistsPatchMetaHashLayer()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.MetaDataHashDataInfo.Size != 0 && GetPatchInfo().HasIndirectTable();
+    }
+
+    public bool ExistsSparseMetaHashLayer()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return _header.MetaDataHashDataInfo.Size != 0 && ExistsSparseLayer();
+    }
+
+    public ref readonly NcaMetaDataHashDataInfo GetPatchMetaDataHashDataInfo()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return ref _header.MetaDataHashDataInfo;
+    }
+
+    public ref readonly NcaMetaDataHashDataInfo GetSparseMetaDataHashDataInfo()
+    {
+        Assert.SdkRequires(IsInitialized());
+        return ref _header.MetaDataHashDataInfo;
+    }
+
+    public void GetRawData(Span<byte> outBuffer)
+    {
+        Assert.SdkRequires(IsInitialized());
+        Assert.SdkRequiresLessEqual(Unsafe.SizeOf<NcaFsHeader>(), outBuffer.Length);
+
+        SpanHelpers.AsReadOnlyByteSpan(in _header).CopyTo(outBuffer);
+    }
+
+    public Result Verify(NcaHeader.ContentType contentType)
+    {
+        Assert.SdkRequires(IsInitialized());
+        Assert.SdkRequiresWithinMinMax((int)contentType, (int)NcaHeader.ContentType.Program, (int)NcaHeader.ContentType.PublicData);
+
+        Result res = _header.Verify();
+        if (res.IsFailure()) return res.Miss();
+
+        const uint programSecureValue = 1;
+        const uint dataSecureValue = 2;
+        const uint htmlDocumentSecureValue = 4;
+        const uint legalInformationSecureValue = 5;
+
+        // Mask out the program index part of the secure value
+        uint secureValue = _header.AesCtrUpperIv.SecureValue & 0xFFFFFF;
+
+        if (GetEncryptionType() == NcaFsHeader.EncryptionType.None)
+        {
+            if (secureValue != 0)
+                return ResultFs.InvalidNcaFsHeader.Log();
+
+            return Result.Success;
+        }
+
+        switch (contentType)
+        {
+            case NcaHeader.ContentType.Program:
+                switch (_fsIndex)
+                {
+                    case 0:
+                        if (secureValue != programSecureValue)
+                            return ResultFs.InvalidNcaFsHeader.Log();
+                        break;
+                    case 1:
+                        if (secureValue != dataSecureValue)
+                            return ResultFs.InvalidNcaFsHeader.Log();
+                        break;
+                    default:
+                        if (secureValue != 0)
+                            return ResultFs.InvalidNcaFsHeader.Log();
+                        break;
+                }
+
+                break;
+            case NcaHeader.ContentType.Manual:
+                if (secureValue != htmlDocumentSecureValue && secureValue != legalInformationSecureValue)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+                break;
+            default:
+                if (secureValue != 0)
+                    return ResultFs.InvalidNcaFsHeader.Log();
+                break;
+        }
+
+        return Result.Success;
+    }
+}

src/LibHac/FsSystem/RuntimeNcaHeader.cs

@@ -0,0 +1,49 @@
+using System;
+using LibHac.Common.FixedArrays;
+
+namespace LibHac.FsSystem;
+
+public struct RuntimeKeySourceInfo
+{
+    public uint Offset;
+    public uint Size;
+    public Hash Hash;
+}
+
+public struct RuntimeNcaHeader
+{
+    public struct FsInfo
+    {
+        public uint StartSector;
+        public uint EndSector;
+        public uint HashSectors;
+        public Hash Hash;
+    }
+
+    public struct SignInfo
+    {
+        public uint Offset;
+        public uint Size;
+        public Hash Hash;
+    }
+
+    public NcaHeader.DistributionType DistributionType;
+    public NcaHeader.ContentType ContentType;
+    public byte KeyGeneration;
+    public ulong ProgramId;
+    public Array16<byte> RightsId;
+    public uint FsHeadersOffset;
+    public Array4<FsInfo> FsInfos;
+    public SignInfo Header2SignInfo;
+    public RuntimeKeySourceInfo KeySourceInfo;
+
+    public static Result CheckUnsupportedVersion(uint magicValue)
+    {
+        throw new NotImplementedException();
+    }
+
+    public Result InitializeCommonForV3(in NcaHeader header, IHash256GeneratorFactorySelector hashGeneratorFactorySelector)
+    {
+        throw new NotImplementedException();
+    }
+}