crypto: implement RSA-2048-PSS

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

@@ -0,0 +1,60 @@
+/*
+ * 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/impl/crypto_bignum.hpp>
+
+namespace ams::crypto {
+
+    template<size_t ModulusSize, size_t ExponentSize>
+    class RsaCalculator {
+        NON_COPYABLE(RsaCalculator);
+        NON_MOVEABLE(RsaCalculator);
+        public:
+            static constexpr inline size_t RequiredWorkBufferSize = 0x10 * ModulusSize;
+        private:
+            impl::StaticBigNum<ModulusSize * BITSIZEOF(u8)> modulus;
+            impl::StaticBigNum<ExponentSize * BITSIZEOF(u8)> exponent;
+        public:
+            RsaCalculator() { /* ... */ }
+            ~RsaCalculator() { this->exponent.ClearToZero(); }
+
+            bool Initialize(const void *mod, size_t mod_size, const void *exp, size_t exp_size) {
+                if (!this->modulus.Import(mod, mod_size) || this->modulus.IsZero()) {
+                    return false;
+                }
+                if (!this->exponent.Import(exp, exp_size) || this->exponent.IsZero()) {
+                    return false;
+                }
+                return true;
+            }
+
+            bool ExpMod(void *dst, const void *src, size_t size, void *work_buf, size_t work_buf_size) {
+                AMS_ASSERT(work_buf_size >= RequiredWorkBufferSize);
+
+                return this->modulus.ExpMod(dst, src, size, this->exponent, static_cast<u32 *>(work_buf), work_buf_size);
+            }
+
+            bool ExpMod(void *dst, const void *src, size_t size) {
+                u32 work_buf[RequiredWorkBufferSize / sizeof(u32)];
+                return this->ExpMod(dst, src, size, work_buf, sizeof(work_buf));
+            }
+    };
+
+}