blob: eb2fd985c968aa138d7a191ca8c2ac18e8aa47c7 [file] [log] [blame]
// Copyright lowRISC contributors.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0
#ifndef OPENTITAN_SW_DEVICE_SILICON_CREATOR_LIB_SIGVERIFY_MOD_EXP_IBEX_H_
#define OPENTITAN_SW_DEVICE_SILICON_CREATOR_LIB_SIGVERIFY_MOD_EXP_IBEX_H_
#include <stdbool.h>
#include <stdint.h>
#include "sw/device/silicon_creator/lib/error.h"
#include "sw/device/silicon_creator/lib/sigverify/rsa_key.h"
#ifdef __cplusplus
extern "C" {
#endif // __cplusplus
/**
* Computes the modular exponentiation of an RSA signature on Ibex.
*
* Given an RSA public key and sig, this function computes sig^e mod n using
* Montgomery multiplication, where
* - sig is an RSA signature,
* - e and n are the exponent and the modulus of the key, respectively.
*
* The key exponent is always 65537; no other exponents are supported.
*
* @param key An RSA public key.
* @param sig Buffer that holds the signature, little-endian.
* @param result Buffer to write the result to, little-endian.
* @return The result of the operation.
*/
rom_error_t sigverify_mod_exp_ibex(const sigverify_rsa_key_t *key,
const sigverify_rsa_buffer_t *sig,
sigverify_rsa_buffer_t *result);
#ifdef __cplusplus
} // extern "C"
#endif // __cplusplus
#endif // OPENTITAN_SW_DEVICE_SILICON_CREATOR_LIB_SIGVERIFY_MOD_EXP_IBEX_H_