fs: utilities for hac2l to print gc headers

libraries/libvapours/include/vapours/crypto/crypto_ccm_decryptor.hpp

@@ -0,0 +1,58 @@
+/*
+ * 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/>.
+ */
+
+#pragma once
+#include <vapours/common.hpp>
+#include <vapours/assert.hpp>
+#include <vapours/util.hpp>
+#include <vapours/crypto/impl/crypto_ccm_mode_impl.hpp>
+
+namespace ams::crypto {
+
+    template<typename BlockCipher>
+    class CcmDecryptor {
+        NON_COPYABLE(CcmDecryptor);
+        NON_MOVEABLE(CcmDecryptor);
+        private:
+            using Impl = impl::CcmModeImpl<BlockCipher>;
+        public:
+            static constexpr size_t KeySize      = Impl::KeySize;
+            static constexpr size_t BlockSize    = Impl::BlockSize;
+            static constexpr size_t MaxMacSize   = BlockSize;
+            static constexpr size_t MaxNonceSize = 13;
+        private:
+            Impl m_impl;
+        public:
+            CcmDecryptor() { /* ... */ }
+
+            void Initialize(const BlockCipher *cipher, const void *nonce, size_t nonce_size, s64 aad_size, s64 data_size, size_t mac_size) {
+                m_impl.Initialize(cipher, nonce, nonce_size, aad_size, data_size, mac_size);
+            }
+
+            size_t Update(void *dst, size_t dst_size, const void *src, size_t src_size) {
+                return m_impl.UpdateDecryption(dst, dst_size, src, src_size);
+            }
+
+            void UpdateAad(const void *aad, size_t aad_size) {
+                return m_impl.UpdateAad(aad, aad_size);
+            }
+
+            void GetMac(void *dst, size_t dst_size) {
+                return m_impl.GetMac(dst, dst_size);
+            }
+    };
+
+}