libs: begin adding capacity for doing crypto on generic os (using externally-preset keys)

libraries/libvapours/source/crypto/impl/crypto_xts_mode_impl.arch.generic.cpp

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 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 <vapours.hpp>
+#include "crypto_update_impl.hpp"
+
+namespace ams::crypto::impl {
+
+    size_t XtsModeImpl::UpdateGeneric(void *dst, size_t dst_size, const void *src, size_t src_size) {
+        AMS_ASSERT(m_state == State_Initialized || m_state == State_Processing);
+
+        return UpdateImpl<void>(this, dst, dst_size, src, src_size);
+    }
+
+    size_t XtsModeImpl::ProcessBlocksGeneric(u8 *dst, const u8 *src, size_t num_blocks) {
+        size_t processed = BlockSize * (num_blocks - 1);
+
+        if (m_state == State_Processing) {
+            this->ProcessBlock(dst, m_last_block);
+            dst       += BlockSize;
+            processed += BlockSize;
+        }
+
+        while ((--num_blocks) > 0) {
+            this->ProcessBlock(dst, src);
+            dst += BlockSize;
+            src += BlockSize;
+        }
+
+        std::memcpy(m_last_block, src, BlockSize);
+
+        m_state = State_Processing;
+
+        return processed;
+    }
+
+    template<> size_t XtsModeImpl::Update<AesEncryptor128>(void *dst, size_t dst_size, const void *src, size_t src_size) { return this->UpdateGeneric(dst, dst_size, src, src_size); }
+    template<> size_t XtsModeImpl::Update<AesEncryptor192>(void *dst, size_t dst_size, const void *src, size_t src_size) { return this->UpdateGeneric(dst, dst_size, src, src_size); }
+    template<> size_t XtsModeImpl::Update<AesEncryptor256>(void *dst, size_t dst_size, const void *src, size_t src_size) { return this->UpdateGeneric(dst, dst_size, src, src_size); }
+
+    template<> size_t XtsModeImpl::Update<AesDecryptor128>(void *dst, size_t dst_size, const void *src, size_t src_size) { return this->UpdateGeneric(dst, dst_size, src, src_size); }
+    template<> size_t XtsModeImpl::Update<AesDecryptor192>(void *dst, size_t dst_size, const void *src, size_t src_size) { return this->UpdateGeneric(dst, dst_size, src, src_size); }
+    template<> size_t XtsModeImpl::Update<AesDecryptor256>(void *dst, size_t dst_size, const void *src, size_t src_size) { return this->UpdateGeneric(dst, dst_size, src, src_size); }
+
+}