Always use an all-zeros key for AES-XTS file systems (#2561)

This commit is contained in:
Alex Barney 2021-08-17 10:46:52 -07:00 committed by GitHub
parent 680d3ed198
commit cd4530f29c
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 65 additions and 0 deletions

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@ -0,0 +1,62 @@
using LibHac;
using LibHac.Common;
using LibHac.Fs;
using LibHac.Fs.Fsa;
using LibHac.FsSrv.FsCreator;
using LibHac.FsSystem;
namespace Ryujinx.HLE.FileSystem
{
public class EncryptedFileSystemCreator : IEncryptedFileSystemCreator
{
public EncryptedFileSystemCreator() { }
public Result Create(out ReferenceCountedDisposable<IFileSystem> encryptedFileSystem, ReferenceCountedDisposable<IFileSystem> baseFileSystem,
EncryptedFsKeyId keyId, in EncryptionSeed encryptionSeed)
{
UnsafeHelpers.SkipParamInit(out encryptedFileSystem);
if (keyId < EncryptedFsKeyId.Save || keyId > EncryptedFsKeyId.CustomStorage)
{
return ResultFs.InvalidArgument.Log();
}
// Force all-zero keys for now since people can open the emulator with different keys or sd seeds sometimes
var fs = new AesXtsFileSystem(baseFileSystem, new byte[0x32], 0x4000);
var aesFileSystem = new ReferenceCountedDisposable<IFileSystem>(fs);
// This wrapper will handle deleting files that were created with different keys
var wrappedFs = new ChangedEncryptionHandlingFileSystem(aesFileSystem);
encryptedFileSystem = new ReferenceCountedDisposable<IFileSystem>(wrappedFs);
return Result.Success;
}
}
public class ChangedEncryptionHandlingFileSystem : ForwardingFileSystem
{
public ChangedEncryptionHandlingFileSystem(ReferenceCountedDisposable<IFileSystem> baseFileSystem) : base(baseFileSystem) { }
protected override Result DoOpenFile(out IFile file, U8Span path, OpenMode mode)
{
UnsafeHelpers.SkipParamInit(out file);
try
{
return base.DoOpenFile(out file, path, mode);
}
catch (HorizonResultException ex)
{
if (ResultFs.AesXtsFileHeaderInvalidKeys.Includes(ex.ResultValue))
{
Result rc = DeleteFile(path);
if (rc.IsFailure()) return rc;
return base.DoOpenFile(out file, path, mode);
}
throw;
}
}
}
}

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@ -178,6 +178,9 @@ namespace Ryujinx.HLE.FileSystem
DefaultFsServerObjects fsServerObjects = DefaultFsServerObjects.GetDefaultEmulatedCreators(serverBaseFs, KeySet, fsServer); DefaultFsServerObjects fsServerObjects = DefaultFsServerObjects.GetDefaultEmulatedCreators(serverBaseFs, KeySet, fsServer);
// Use our own encrypted fs creator that always uses all-zero keys
fsServerObjects.FsCreators.EncryptedFileSystemCreator = new EncryptedFileSystemCreator();
GameCard = fsServerObjects.GameCard; GameCard = fsServerObjects.GameCard;
SdCard = fsServerObjects.SdCard; SdCard = fsServerObjects.SdCard;