kopia lustrzana https://github.com/espressif/esp-idf
230 wiersze
6.5 KiB
C
230 wiersze
6.5 KiB
C
/*
|
|
* Multi-precision integer library
|
|
* ESP32 H4 hardware accelerated parts based on mbedTLS implementation
|
|
*
|
|
* SPDX-FileCopyrightText: The Mbed TLS Contributors
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* SPDX-FileContributor: 2016-2022 Espressif Systems (Shanghai) CO LTD
|
|
*/
|
|
#include <string.h>
|
|
#include <sys/param.h>
|
|
#include "soc/hwcrypto_periph.h"
|
|
#include "esp_private/periph_ctrl.h"
|
|
#include "mbedtls/bignum.h"
|
|
#include "bignum_impl.h"
|
|
#include "soc/system_reg.h"
|
|
#include "soc/periph_defs.h"
|
|
#include "esp_crypto_lock.h"
|
|
|
|
|
|
size_t esp_mpi_hardware_words(size_t words)
|
|
{
|
|
return words;
|
|
}
|
|
|
|
void esp_mpi_enable_hardware_hw_op( void )
|
|
{
|
|
esp_crypto_mpi_lock_acquire();
|
|
|
|
/* Enable RSA hardware */
|
|
periph_module_enable(PERIPH_RSA_MODULE);
|
|
|
|
REG_CLR_BIT(SYSTEM_RSA_PD_CTRL_REG, SYSTEM_RSA_MEM_PD);
|
|
|
|
while (REG_READ(RSA_QUERY_CLEAN_REG) != 1) {
|
|
}
|
|
// Note: from enabling RSA clock to here takes about 1.3us
|
|
|
|
REG_WRITE(RSA_INTERRUPT_REG, 0);
|
|
}
|
|
|
|
void esp_mpi_disable_hardware_hw_op( void )
|
|
{
|
|
REG_SET_BIT(SYSTEM_RSA_PD_CTRL_REG, SYSTEM_RSA_MEM_PD);
|
|
|
|
/* Disable RSA hardware */
|
|
periph_module_disable(PERIPH_RSA_MODULE);
|
|
|
|
esp_crypto_mpi_lock_release();
|
|
}
|
|
|
|
void esp_mpi_interrupt_enable( bool enable )
|
|
{
|
|
REG_WRITE(RSA_INTERRUPT_REG, enable);
|
|
}
|
|
|
|
void esp_mpi_interrupt_clear( void )
|
|
{
|
|
REG_WRITE(RSA_CLEAR_INTERRUPT_REG, 1);
|
|
}
|
|
|
|
/* Copy mbedTLS MPI bignum 'mpi' to hardware memory block at 'mem_base'.
|
|
|
|
If num_words is higher than the number of words in the bignum then
|
|
these additional words will be zeroed in the memory buffer.
|
|
*/
|
|
static inline void mpi_to_mem_block(uint32_t mem_base, const mbedtls_mpi *mpi, size_t num_words)
|
|
{
|
|
uint32_t *pbase = (uint32_t *)mem_base;
|
|
uint32_t copy_words = MIN(num_words, mpi->MBEDTLS_PRIVATE(n));
|
|
|
|
/* Copy MPI data to memory block registers */
|
|
for (int i = 0; i < copy_words; i++) {
|
|
pbase[i] = mpi->MBEDTLS_PRIVATE(p)[i];
|
|
}
|
|
|
|
/* Zero any remaining memory block data */
|
|
for (int i = copy_words; i < num_words; i++) {
|
|
pbase[i] = 0;
|
|
}
|
|
}
|
|
|
|
/* Read mbedTLS MPI bignum back from hardware memory block.
|
|
|
|
Reads num_words words from block.
|
|
*/
|
|
static inline void mem_block_to_mpi(mbedtls_mpi *x, uint32_t mem_base, int num_words)
|
|
{
|
|
|
|
/* Copy data from memory block registers */
|
|
const size_t REG_WIDTH = sizeof(uint32_t);
|
|
for (size_t i = 0; i < num_words; i++) {
|
|
x->MBEDTLS_PRIVATE(p)[i] = REG_READ(mem_base + (i * REG_WIDTH));
|
|
}
|
|
/* Zero any remaining limbs in the bignum, if the buffer is bigger
|
|
than num_words */
|
|
for (size_t i = num_words; i < x->MBEDTLS_PRIVATE(n); i++) {
|
|
x->MBEDTLS_PRIVATE(p)[i] = 0;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/* Begin an RSA operation. op_reg specifies which 'START' register
|
|
to write to.
|
|
*/
|
|
static inline void start_op(uint32_t op_reg)
|
|
{
|
|
/* Clear interrupt status */
|
|
REG_WRITE(RSA_CLEAR_INTERRUPT_REG, 1);
|
|
|
|
/* Note: above REG_WRITE includes a memw, so we know any writes
|
|
to the memory blocks are also complete. */
|
|
|
|
REG_WRITE(op_reg, 1);
|
|
}
|
|
|
|
/* Wait for an RSA operation to complete.
|
|
*/
|
|
static inline void wait_op_complete(void)
|
|
{
|
|
while (REG_READ(RSA_QUERY_INTERRUPT_REG) != 1)
|
|
{ }
|
|
|
|
/* clear the interrupt */
|
|
REG_WRITE(RSA_CLEAR_INTERRUPT_REG, 1);
|
|
}
|
|
|
|
|
|
/* Read result from last MPI operation */
|
|
void esp_mpi_read_result_hw_op(mbedtls_mpi *Z, size_t z_words)
|
|
{
|
|
wait_op_complete();
|
|
mem_block_to_mpi(Z, RSA_MEM_Z_BLOCK_BASE, z_words);
|
|
}
|
|
|
|
|
|
/* Z = (X * Y) mod M
|
|
|
|
Not an mbedTLS function
|
|
*/
|
|
void esp_mpi_mul_mpi_mod_hw_op(const mbedtls_mpi *X, const mbedtls_mpi *Y, const mbedtls_mpi *M, const mbedtls_mpi *Rinv, mbedtls_mpi_uint Mprime, size_t num_words)
|
|
{
|
|
REG_WRITE(RSA_LENGTH_REG, (num_words - 1));
|
|
|
|
/* Load M, X, Rinv, Mprime (Mprime is mod 2^32) */
|
|
mpi_to_mem_block(RSA_MEM_X_BLOCK_BASE, X, num_words);
|
|
mpi_to_mem_block(RSA_MEM_Y_BLOCK_BASE, Y, num_words);
|
|
mpi_to_mem_block(RSA_MEM_M_BLOCK_BASE, M, num_words);
|
|
mpi_to_mem_block(RSA_MEM_RB_BLOCK_BASE, Rinv, num_words);
|
|
REG_WRITE(RSA_M_DASH_REG, Mprime);
|
|
|
|
start_op(RSA_MOD_MULT_START_REG);
|
|
}
|
|
|
|
/* Z = (X ^ Y) mod M
|
|
*/
|
|
void esp_mpi_exp_mpi_mod_hw_op(const mbedtls_mpi *X, const mbedtls_mpi *Y, const mbedtls_mpi *M, const mbedtls_mpi *Rinv, mbedtls_mpi_uint Mprime, size_t num_words)
|
|
{
|
|
size_t y_bits = mbedtls_mpi_bitlen(Y);
|
|
|
|
REG_WRITE(RSA_LENGTH_REG, (num_words - 1));
|
|
|
|
/* Load M, X, Rinv, Mprime (Mprime is mod 2^32) */
|
|
mpi_to_mem_block(RSA_MEM_X_BLOCK_BASE, X, num_words);
|
|
mpi_to_mem_block(RSA_MEM_Y_BLOCK_BASE, Y, num_words);
|
|
mpi_to_mem_block(RSA_MEM_M_BLOCK_BASE, M, num_words);
|
|
mpi_to_mem_block(RSA_MEM_RB_BLOCK_BASE, Rinv, num_words);
|
|
REG_WRITE(RSA_M_DASH_REG, Mprime);
|
|
|
|
/* Enable acceleration options */
|
|
REG_WRITE(RSA_CONSTANT_TIME_REG, 0);
|
|
REG_WRITE(RSA_SEARCH_ENABLE_REG, 1);
|
|
REG_WRITE(RSA_SEARCH_POS_REG, y_bits - 1);
|
|
|
|
/* Execute first stage montgomery multiplication */
|
|
start_op(RSA_MODEXP_START_REG);
|
|
|
|
REG_WRITE(RSA_SEARCH_ENABLE_REG, 0);
|
|
}
|
|
|
|
|
|
/* Z = X * Y */
|
|
void esp_mpi_mul_mpi_hw_op(const mbedtls_mpi *X, const mbedtls_mpi *Y, size_t num_words)
|
|
{
|
|
/* Copy X (right-extended) & Y (left-extended) to memory block */
|
|
mpi_to_mem_block(RSA_MEM_X_BLOCK_BASE, X, num_words);
|
|
mpi_to_mem_block(RSA_MEM_Z_BLOCK_BASE + num_words * 4, Y, num_words);
|
|
/* NB: as Y is left-extended, we don't zero the bottom words_mult words of Y block.
|
|
This is OK for now because zeroing is done by hardware when we do esp_mpi_acquire_hardware().
|
|
*/
|
|
REG_WRITE(RSA_LENGTH_REG, (num_words * 2 - 1));
|
|
start_op(RSA_MULT_START_REG);
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* @brief Special-case of (X * Y), where we use hardware montgomery mod
|
|
multiplication to calculate result where either A or B are >2048 bits so
|
|
can't use the standard multiplication method.
|
|
*
|
|
*/
|
|
void esp_mpi_mult_mpi_failover_mod_mult_hw_op(const mbedtls_mpi *X, const mbedtls_mpi *Y, size_t num_words)
|
|
{
|
|
/* M = 2^num_words - 1, so block is entirely FF */
|
|
for (int i = 0; i < num_words; i++) {
|
|
REG_WRITE(RSA_MEM_M_BLOCK_BASE + i * 4, UINT32_MAX);
|
|
}
|
|
|
|
/* Mprime = 1 */
|
|
REG_WRITE(RSA_M_DASH_REG, 1);
|
|
REG_WRITE(RSA_LENGTH_REG, num_words - 1);
|
|
|
|
/* Load X & Y */
|
|
mpi_to_mem_block(RSA_MEM_X_BLOCK_BASE, X, num_words);
|
|
mpi_to_mem_block(RSA_MEM_Y_BLOCK_BASE, Y, num_words);
|
|
|
|
/* Rinv = 1, write first word */
|
|
REG_WRITE(RSA_MEM_RB_BLOCK_BASE, 1);
|
|
|
|
/* Zero out rest of the Rinv words */
|
|
for (int i = 1; i < num_words; i++) {
|
|
REG_WRITE(RSA_MEM_RB_BLOCK_BASE + i * 4, 0);
|
|
}
|
|
|
|
start_op(RSA_MOD_MULT_START_REG);
|
|
}
|