Implement support for parsing/interacting with NCAs. (#942)

* fs: implement support for interacting with ncas.

* spl: extend to use virtual keyslots

libraries/libstratosphere/source/fssystem/fssystem_integrity_romfs_storage.cpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+
+namespace ams::fssystem {
+
+    Result IntegrityRomFsStorage::Initialize(save::HierarchicalIntegrityVerificationInformation level_hash_info, Hash master_hash, save::HierarchicalIntegrityVerificationStorage::HierarchicalStorageInformation storage_info, IBufferManager *bm) {
+        /* Validate preconditions. */
+        AMS_ASSERT(bm != nullptr);
+
+        /* Set master hash. */
+        this->master_hash = master_hash;
+        this->master_hash_storage = std::make_unique<fs::MemoryStorage>(std::addressof(this->master_hash), sizeof(Hash));
+        R_UNLESS(this->master_hash_storage != nullptr, fs::ResultAllocationFailureInIntegrityRomFsStorageA());
+
+        /* Set the master hash storage. */
+        storage_info[0] = fs::SubStorage(this->master_hash_storage.get(), 0, sizeof(Hash));
+
+        /* Set buffers. */
+        for (size_t i = 0; i < util::size(this->buffers.buffers); ++i) {
+            this->buffers.buffers[i] = bm;
+        }
+
+        /* Initialize our integrity storage. */
+        return this->integrity_storage.Initialize(level_hash_info, storage_info, std::addressof(this->buffers), std::addressof(this->mutex), fs::StorageType_RomFs);
+    }
+
+    void IntegrityRomFsStorage::Finalize() {
+        this->integrity_storage.Finalize();
+    }
+
+}