/*
 * Copyright (c) 2018-2019 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 <switch.h>
#include <stratosphere.hpp>

#include "spl_types.hpp"

class SecureMonitorWrapper {
    public:
        static constexpr size_t MaxAesKeyslots = 6;
        static constexpr size_t MaxAesKeyslotsDeprecated = 4;
    private:
        const void *keyslot_owners[MaxAesKeyslots] = {};
        BootReasonValue boot_reason = {};
        bool boot_reason_set = false;
    private:
        static size_t GetMaxKeyslots() {
            return (GetRuntimeFirmwareVersion() >= FirmwareVersion_600) ? MaxAesKeyslots : MaxAesKeyslotsDeprecated;
        }
    private:
        BootReasonValue GetBootReason() const {
            return this->boot_reason;
        }
        bool IsBootReasonSet() const {
            return this->boot_reason_set;
        }
        static Result ConvertToSplResult(SmcResult result);
    private:
        static void InitializeCtrDrbg();
        static void InitializeSeEvents();
        static void InitializeDeviceAddressSpace();
    public:
        static void Initialize();
    private:
        Result GenerateRandomBytesInternal(void *out, size_t size);
        void WaitSeOperationComplete();
        SmcResult WaitCheckStatus(AsyncOperationKey op_key);
        SmcResult WaitGetResult(void *out_buf, size_t out_buf_size, AsyncOperationKey op_key);
        Result ValidateAesKeyslot(u32 keyslot, const void *owner);
        SmcResult DecryptAesBlock(u32 keyslot, void *dst, const void *src);
        Result ImportSecureExpModKey(const void *src, size_t src_size, const AccessKey &access_key, const KeySource &key_source, u32 option);
        Result SecureExpMod(void *out, size_t out_size, const void *base, size_t base_size, const void *mod, size_t mod_size, u32 option);
    public:
        /* General. */
        Result GetConfig(u64 *out, SplConfigItem which);
        Result ExpMod(void *out, size_t out_size, const void *base, size_t base_size, const void *exp, size_t exp_size, const void *mod, size_t mod_size);
        Result SetConfig(SplConfigItem which, u64 value);
        Result GenerateRandomBytes(void *out, size_t size);
        Result IsDevelopment(bool *out);
        Result SetBootReason(BootReasonValue boot_reason);
        Result GetBootReason(BootReasonValue *out);

        /* Crypto. */
        Result GenerateAesKek(AccessKey *out_access_key, const KeySource &key_source, u32 generation, u32 option);
        Result LoadAesKey(u32 keyslot, const void *owner, const AccessKey &access_key, const KeySource &key_source);
        Result GenerateAesKey(AesKey *out_key, const AccessKey &access_key, const KeySource &key_source);
        Result DecryptAesKey(AesKey *out_key, const KeySource &key_source, u32 generation, u32 option);
        Result CryptAesCtr(void *dst, size_t dst_size, u32 keyslot, const void *owner, const void *src, size_t src_size, const IvCtr &iv_ctr);
        Result ComputeCmac(Cmac *out_cmac, u32 keyslot, const void *owner, const void *data, size_t size);
        Result AllocateAesKeyslot(u32 *out_keyslot, const void *owner);
        Result FreeAesKeyslot(u32 keyslot, const void *owner);

        /* RSA. */
        Result DecryptRsaPrivateKey(void *dst, size_t dst_size, const void *src, size_t src_size, const AccessKey &access_key, const KeySource &key_source, u32 option);

        /* SSL */
        Result ImportSslKey(const void *src, size_t src_size, const AccessKey &access_key, const KeySource &key_source);
        Result SslExpMod(void *out, size_t out_size, const void *base, size_t base_size, const void *mod, size_t mod_size);

        /* ES */
        Result ImportEsKey(const void *src, size_t src_size, const AccessKey &access_key, const KeySource &key_source, u32 option);
        Result ImportDrmKey(const void *src, size_t src_size, const AccessKey &access_key, const KeySource &key_source);
        Result DrmExpMod(void *out, size_t out_size, const void *base, size_t base_size, const void *mod, size_t mod_size);

        /* Helper. */
        Result FreeAesKeyslots(const void *owner);
        Handle GetAesKeyslotAvailableEventHandle();
    private:
        class ScopedAesKeyslot {
            private:
                SecureMonitorWrapper *secmon_wrapper;
                u32 slot;
                bool has_slot;
            public:
                ScopedAesKeyslot(SecureMonitorWrapper *sw) : secmon_wrapper(sw), slot(0), has_slot(false) {
                    /* ... */
                }
                ~ScopedAesKeyslot() {
                    if (has_slot) {
                        this->secmon_wrapper->FreeAesKeyslot(slot, this);
                    }
                }

                u32 GetKeyslot() const {
                    return this->slot;
                }

                Result Allocate() {
                    Result rc = this->secmon_wrapper->AllocateAesKeyslot(&this->slot, this);
                    if (R_SUCCEEDED(rc)) {
                        this->has_slot = true;
                    }
                    return rc;
                }
        };
};