crypto: implement RSA-2048-PSS

libraries/libvapours/include/vapours/crypto/impl/crypto_hash_function.hpp

@@ -0,0 +1,37 @@
+/*
+ * 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/>.
+ */
+
+#pragma once
+#include <vapours/common.hpp>
+#include <vapours/assert.hpp>
+#include <vapours/util.hpp>
+#include <vapours/crypto/crypto_memory_compare.hpp>
+#include <vapours/crypto/crypto_memory_clear.hpp>
+
+namespace ams::crypto::impl {
+
+    /* TODO: C++20
+        template<typename T>
+        concept HashFunction = requires(T &t, const void *cv, void *v, size_t sz) {
+            { T::HashSize      } -> std::same_as<size_t>;
+            { T::BlockSize     } -> std::same_as<size_t>;
+            { t.Initialize()   } -> std::same_as<void>;
+            { t.Update(cv, sz) } -> std::same_as<void>;
+            { t.GetHash(v, sz) } -> std::same_as<void>;
+        };
+    */
+
+}