public static IStorage OpenStorage(this Nca nca, NcaSectionType type, IntegrityCheckLevel integrityCheckLevel,
bool openRaw)
{
if (openRaw)
{
return(nca.OpenRawStorage(type));
}
return(nca.OpenStorage(type, integrityCheckLevel));
}
public static IStorage OpenStorage(this Nca nca, int index, IntegrityCheckLevel integrityCheckLevel,
bool openRaw)
{
if (openRaw)
{
return(nca.OpenRawStorage(index));
}
return(nca.OpenStorage(index, integrityCheckLevel));
}
public IStorage OpenRawStorageWithPatch(Nca patchNca, int index)
{
IStorage patchStorage = patchNca.OpenRawStorage(index);
IStorage baseStorage = SectionExists(index) ? OpenRawStorage(index) : new NullStorage();
NcaFsHeader header = patchNca.Header.GetFsHeader(index);
NcaFsPatchInfo patchInfo = header.GetPatchInfo();
if (patchInfo.RelocationTreeSize == 0)
{
return(patchStorage);
}
IStorage relocationTableStorage = patchStorage.Slice(patchInfo.RelocationTreeOffset, patchInfo.RelocationTreeSize);
return(new IndirectStorage(relocationTableStorage, true, baseStorage, patchStorage));
}
private static Validity ValidateCtrExDecryption(Nca nca, int index)
{
// The encryption subsection table in an AesCtrEx-encrypted partition contains the length of the entire partition.
// The encryption table is always located immediately following the partition data, so the offset value of the encryption
// table located in the NCA header should be the same as the size read from the encryption table.
Debug.Assert(nca.CanOpenSection(index));
NcaFsPatchInfo header = nca.Header.GetFsHeader(index).GetPatchInfo();
IStorage decryptedStorage = nca.OpenRawStorage(index);
Span <byte> buffer = stackalloc byte[sizeof(long)];
decryptedStorage.Read(header.EncryptionTreeOffset + 8, buffer).ThrowIfFailure();
long readDataSize = BinaryPrimitives.ReadInt64LittleEndian(buffer);
if (header.EncryptionTreeOffset != readDataSize)
{
return(Validity.Invalid);
}
return(Validity.Valid);
}
public IStorage OpenRawStorageWithPatch(Nca patchNca, int index)
{
IStorage patchStorage = patchNca.OpenRawStorage(index);
IStorage baseStorage = SectionExists(index) ? OpenRawStorage(index) : new NullStorage();
patchStorage.GetSize(out long patchSize).ThrowIfFailure();
baseStorage.GetSize(out long baseSize).ThrowIfFailure();
NcaFsHeader header = patchNca.Header.GetFsHeader(index);
NcaFsPatchInfo patchInfo = header.GetPatchInfo();
if (patchInfo.RelocationTreeSize == 0)
{
return(patchStorage);
}
var treeHeader = new BucketTree.Header();
patchInfo.RelocationTreeHeader.CopyTo(SpanHelpers.AsByteSpan(ref treeHeader));
long nodeStorageSize = IndirectStorage.QueryNodeStorageSize(treeHeader.EntryCount);
long entryStorageSize = IndirectStorage.QueryEntryStorageSize(treeHeader.EntryCount);
var relocationTableStorage = new SubStorage(patchStorage, patchInfo.RelocationTreeOffset, patchInfo.RelocationTreeSize);
var cachedTableStorage = new CachedStorage(relocationTableStorage, IndirectStorage.NodeSize, 4, true);
var tableNodeStorage = new SubStorage(cachedTableStorage, 0, nodeStorageSize);
var tableEntryStorage = new SubStorage(cachedTableStorage, nodeStorageSize, entryStorageSize);
var storage = new IndirectStorage();
storage.Initialize(tableNodeStorage, tableEntryStorage, treeHeader.EntryCount).ThrowIfFailure();
storage.SetStorage(0, baseStorage, 0, baseSize);
storage.SetStorage(1, patchStorage, 0, patchSize);
return(storage);
}
public static Validity ValidateSectionMasterHash(this Nca nca, int index)
{
if (!nca.SectionExists(index))
{
throw new ArgumentException(nameof(index), Messages.NcaSectionMissing);
}
if (!nca.CanOpenSection(index))
{
return(Validity.MissingKey);
}
NcaFsHeader header = nca.Header.GetFsHeader(index);
// The base data is needed to validate the hash, so use a trick involving the AES-CTR extended
// encryption table to check if the decryption is invalid.
// todo: If the patch replaces the data checked by the master hash, use that directly
if (header.IsPatchSection())
{
if (header.EncryptionType != NcaEncryptionType.AesCtrEx)
{
return(Validity.Unchecked);
}
Validity ctrExValidity = ValidateCtrExDecryption(nca, index);
return(ctrExValidity == Validity.Invalid ? Validity.Invalid : Validity.Unchecked);
}
byte[] expectedHash;
long offset;
long size;
switch (header.HashType)
{
case NcaHashType.Ivfc:
NcaFsIntegrityInfoIvfc ivfcInfo = header.GetIntegrityInfoIvfc();
expectedHash = ivfcInfo.MasterHash.ToArray();
offset = ivfcInfo.GetLevelOffset(0);
size = 1 << ivfcInfo.GetLevelBlockSize(0);
break;
case NcaHashType.Sha256:
NcaFsIntegrityInfoSha256 sha256Info = header.GetIntegrityInfoSha256();
expectedHash = sha256Info.MasterHash.ToArray();
offset = sha256Info.GetLevelOffset(0);
size = sha256Info.GetLevelSize(0);
break;
default:
return(Validity.Unchecked);
}
IStorage storage = nca.OpenRawStorage(index);
var data = new byte[size];
storage.Read(offset, data).ThrowIfFailure();
var actualHash = new byte[Sha256.DigestSize];
Sha256.GenerateSha256Hash(data, actualHash);
if (Utilities.ArraysEqual(expectedHash, actualHash))
{
return(Validity.Valid);
}
return(Validity.Invalid);
}