/*
 * SPDX-FileCopyrightText: 2020 Foundation Devices, Inc. <hello@foundationdevices.com>
 * SPDX-License-Identifier: GPL-3.0-or-later
 */
#ifndef _SECURE_ELEMENT_H_
#define _SECURE_ELEMENT_H_

#include <stdbool.h>

// Status/Error Codes that occur in 4-byte groups. See page 50, table 9-3.
#define SE_COMMAND_OK			0x00
#define SE_CHECKMAC_FAIL		0x01
#define SE_PARSE_ERROR			0x03
#define SE_ECC_FAULT			0x05
#define SE_SELFTEST_ERROR		0x07
#define SE_EXEC_ERROR			0x0f
#define SE_AFTER_WAKE			0x11
#define SE_WATCHDOG_EXPIRE		0xEE
#define SE_COMM_ERROR			0xFF

#if 0
// break on any error: not helpful since some are normal
# define ERR(msg)            BREAKPOINT;
# define ERRV(val, msg)       BREAKPOINT;
#else
# define ERR(msg)
# define ERRV(val, msg)
#endif

// Opcodes from table 9-4, page 51
//
typedef enum {
    OP_CheckMac = 0x28, OP_Counter = 0x24, OP_DeriveKey = 0x1C, OP_ECDH = 0x43,
    OP_GenDig = 0x15, OP_GenKey = 0x40, OP_Info = 0x30,
    OP_Lock = 0x17, OP_MAC = 0x08, OP_Nonce = 0x16,
    OP_PrivWrite = 0x46, OP_Random = 0x1B, OP_Read = 0x02, OP_Sign = 0x41,
    OP_SHA = 0x47, OP_UpdateExtra = 0x20, OP_Verify = 0x45, OP_Write = 0x12,
    OP_AES = 0x51,
    OP_KDF = 0x56,
    OP_SecureBoot = 0x80,
    OP_SelftTest = 0x77,
} seopcode_t;

extern const char *copyright_msg;

extern void se_setup(void);
extern void se_reset_chip(void);
extern void se_keep_alive(void);
extern int  se_wake(void);
extern void se_idle(void);
extern void se_sleep(void);
extern void se_crc16_chain(uint8_t length, const uint8_t *data, uint8_t crc[2]);
extern void se_write(seopcode_t opcode, uint8_t p1, uint16_t p2, uint8_t *data, uint8_t data_len);
extern int  se_read(uint8_t *data, uint8_t len);
extern int  se_read1(void);
extern int  se_read_data_slot(int slot_num, uint8_t *data, int len);
extern int  se_config_read(uint8_t *config);
extern int  se_pair_unlock(void);
extern int  se_checkmac(uint8_t keynum, const uint8_t *secret);
extern int  se_checkmac_hard(uint8_t keynum, const uint8_t *secret);
extern int  se_gendig_slot(int slot_num, const uint8_t *slot_contents, uint8_t *digest);
extern bool se_is_correct_tempkey(const uint8_t *expected_tempkey);
extern int  se_pick_nonce(uint8_t *num_in, uint8_t *tempkey);
extern int  se_encrypted_read(int data_slot, int read_kn, const uint8_t *read_key, uint8_t *data, int len);
extern int  se_encrypted_write(int data_slot, int write_kn, const uint8_t *write_key, const uint8_t *data, int len);
extern int  se_get_counter(uint32_t *result, uint8_t counter_number);
extern int  se_add_counter(uint32_t *result, uint8_t counter_number, int incr);
extern int  se_gendig_counter(int counter_num, const uint32_t expected_value, uint8_t digest[32]);

extern uint8_t se_show_error(void);

#endif /* _SECURE_ELEMENT_H_ */