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optimize hardware encryption when using ECC certificate

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This commit is contained in:
xutao 2020-11-17 17:50:05 +08:00
parent bea8c46ba6
commit c4352192a4
1 changed files with 122 additions and 66 deletions
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188
components/mbedtls/port/esp_bignum.c
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@ -63,29 +63,6 @@ static const __attribute__((unused)) char *TAG = "bignum";
#define ciL (sizeof(mbedtls_mpi_uint)) /* chars in limb */
#define biL (ciL << 3) /* bits in limb */
#if defined(CONFIG_MBEDTLS_MPI_USE_INTERRUPT)
static SemaphoreHandle_t op_complete_sem;
static IRAM_ATTR void rsa_complete_isr(void *arg)
{
BaseType_t higher_woken;
DPORT_REG_WRITE(RSA_INTERRUPT_REG, 1);
xSemaphoreGiveFromISR(op_complete_sem, &higher_woken);
if (higher_woken) {
portYIELD_FROM_ISR();
}
}
static void rsa_isr_initialise()
{
if (op_complete_sem == NULL) {
op_complete_sem = xSemaphoreCreateBinary();
esp_intr_alloc(ETS_RSA_INTR_SOURCE, 0, rsa_complete_isr, NULL, NULL);
}
}
#endif /* CONFIG_MBEDTLS_MPI_USE_INTERRUPT */
static _lock_t mpi_lock;
void esp_mpi_acquire_hardware( void )
@ -100,9 +77,6 @@ void esp_mpi_acquire_hardware( void )
while(DPORT_REG_READ(RSA_CLEAN_REG) != 1);
// Note: from enabling RSA clock to here takes about 1.3us
#ifdef CONFIG_MBEDTLS_MPI_USE_INTERRUPT
rsa_isr_initialise();
#endif
}
void esp_mpi_release_hardware( void )
@ -267,19 +241,12 @@ static inline void start_op(uint32_t op_reg)
*/
static inline void wait_op_complete(uint32_t op_reg)
{
#ifdef CONFIG_MBEDTLS_MPI_USE_INTERRUPT
if (!xSemaphoreTake(op_complete_sem, 2000 / portTICK_PERIOD_MS)) {
ESP_LOGE(TAG, "Timed out waiting for RSA operation (op_reg 0x%x int_reg 0x%x)",
op_reg, DPORT_REG_READ(RSA_INTERRUPT_REG));
abort(); /* indicates a fundamental problem with driver */
}
#else
while(DPORT_REG_READ(RSA_INTERRUPT_REG) != 1)
{ }
/* clear the interrupt */
DPORT_REG_WRITE(RSA_INTERRUPT_REG, 1);
#endif
}
@ -338,14 +305,129 @@ int esp_mpi_mul_mpi_mod(mbedtls_mpi *Z, const mbedtls_mpi *X, const mbedtls_mpi
#if defined(MBEDTLS_MPI_EXP_MOD_ALT)
static int mont(mbedtls_mpi* Z, const mbedtls_mpi* X, const mbedtls_mpi* Y, const mbedtls_mpi* M,
mbedtls_mpi_uint Mprime,
size_t hw_words,
bool again)
{
// Note Z may be the same pointer as X or Y
int ret = 0;
// montgomery mult prepare
if (again == false) {
mpi_to_mem_block(RSA_MEM_M_BLOCK_BASE, M, hw_words);
DPORT_REG_WRITE(RSA_M_DASH_REG, Mprime);
DPORT_REG_WRITE(RSA_MULT_MODE_REG, hw_words / 16 - 1);
}
mpi_to_mem_block(RSA_MEM_X_BLOCK_BASE, X, hw_words);
mpi_to_mem_block(RSA_MEM_RB_BLOCK_BASE, Y, hw_words);
start_op(RSA_MULT_START_REG);
Z->s = 1;
MBEDTLS_MPI_CHK( mbedtls_mpi_grow(Z, hw_words) );
wait_op_complete(RSA_MULT_START_REG);
/* Read back the result */
mem_block_to_mpi(Z, RSA_MEM_Z_BLOCK_BASE, hw_words);
/* from HAC 14.36 - 3. If Z >= M then Z = Z - M */
if (mbedtls_mpi_cmp_mpi(Z, M) >= 0) {
MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(Z, Z, M));
}
cleanup:
return ret;
}
/*
* Sliding-window exponentiation: Z = X^Y mod M (HAC 14.85)
* Return the most significant one-bit.
*
* _Rinv is optional pre-calculated version of Rinv (via calculate_rinv()).
*
* (See RSA Accelerator section in Technical Reference for more about Mprime, Rinv)
*
*/
static size_t mbedtls_mpi_msb( const mbedtls_mpi* X )
{
int i, j;
if (X != NULL && X->n != 0) {
for (i = X->n - 1; i >= 0; i--) {
if (X->p[i] != 0) {
for (j = biL - 1; j >= 0; j--) {
if ((X->p[i] & (1 << j)) != 0) {
return (i * biL) + j;
}
}
}
}
}
return 0;
}
/*
* Montgomery exponentiation: Z = X ^ Y mod M (HAC 14.94)
*/
static int mpi_montgomery_exp_calc( mbedtls_mpi* Z, const mbedtls_mpi* X, const mbedtls_mpi* Y, const mbedtls_mpi* M,
mbedtls_mpi* Rinv,
size_t hw_words,
mbedtls_mpi_uint Mprime )
{
int ret = 0;
mbedtls_mpi X_, one;
mbedtls_mpi_init(&X_);
mbedtls_mpi_init(&one);
if( ( ( ret = mbedtls_mpi_grow(&one, hw_words) ) != 0 ) ||
( ( ret = mbedtls_mpi_set_bit(&one, 0, 1) ) != 0 ) ) {
goto cleanup2;
}
// Algorithm from HAC 14.94
{
// 0 determine t (highest bit set in y)
int t = mbedtls_mpi_msb(Y);
esp_mpi_acquire_hardware();
// 1.1 x_ = mont(x, R^2 mod m)
// = mont(x, rb)
MBEDTLS_MPI_CHK( mont(&X_, X, Rinv, M, Mprime, hw_words, false) );
// 1.2 z = R mod m
// now z = R mod m = Mont (R^2 mod m, 1) mod M (as Mont(x) = X&R^-1 mod M)
MBEDTLS_MPI_CHK( mont(Z, Rinv, &one, M, Mprime, hw_words, true) );
// 2 for i from t down to 0
for (int i = t; i >= 0; i--) {
// 2.1 z = mont(z,z)
if (i != t) { // skip on the first iteration as is still unity
MBEDTLS_MPI_CHK( mont(Z, Z, Z, M, Mprime, hw_words, true) );
}
// 2.2 if y[i] = 1 then z = mont(A, x_)
if (mbedtls_mpi_get_bit(Y, i)) {
MBEDTLS_MPI_CHK( mont(Z, Z, &X_, M, Mprime, hw_words, true) );
}
}
// 3 z = Mont(z, 1)
MBEDTLS_MPI_CHK( mont(Z, Z, &one, M, Mprime, hw_words, true) );
}
cleanup:
mbedtls_mpi_free(&X_);
mbedtls_mpi_free(&one);
esp_mpi_release_hardware();
return ret;
cleanup2:
mbedtls_mpi_free(&one);
return ret;
}
int mbedtls_mpi_exp_mod( mbedtls_mpi* Z, const mbedtls_mpi* X, const mbedtls_mpi* Y, const mbedtls_mpi* M, mbedtls_mpi* _Rinv )
{
int ret = 0;
@ -392,31 +474,7 @@ int mbedtls_mpi_exp_mod( mbedtls_mpi* Z, const mbedtls_mpi* X, const mbedtls_mpi
Mprime = modular_inverse(M);
esp_mpi_acquire_hardware();
/* "mode" register loaded with number of 512-bit blocks, minus 1 */
DPORT_REG_WRITE(RSA_MODEXP_MODE_REG, (hw_words / 16) - 1);
/* Load M, X, Rinv, M-prime (M-prime is mod 2^32) */
mpi_to_mem_block(RSA_MEM_X_BLOCK_BASE, X, hw_words);
mpi_to_mem_block(RSA_MEM_Y_BLOCK_BASE, Y, hw_words);
mpi_to_mem_block(RSA_MEM_M_BLOCK_BASE, M, hw_words);
mpi_to_mem_block(RSA_MEM_RB_BLOCK_BASE, Rinv, hw_words);
DPORT_REG_WRITE(RSA_M_DASH_REG, Mprime);
start_op(RSA_START_MODEXP_REG);
/* X ^ Y may actually be shorter than M, but unlikely when used for crypto */
if ((ret = mbedtls_mpi_grow(Z, m_words)) != 0) {
esp_mpi_release_hardware();
goto cleanup;
}
wait_op_complete(RSA_START_MODEXP_REG);
mem_block_to_mpi(Z, RSA_MEM_Z_BLOCK_BASE, m_words);
esp_mpi_release_hardware();
MBEDTLS_MPI_CHK( mpi_montgomery_exp_calc(Z, X, Y, M, Rinv, hw_words, Mprime) );
// Compensate for negative X
if (X->s == -1 && (Y->p[0] & 1) != 0) {
Z->s = -1;
@ -458,7 +516,7 @@ static int modular_multiply_finish(mbedtls_mpi *Z, const mbedtls_mpi *X, const m
mpi_to_mem_block(RSA_MEM_X_BLOCK_BASE, Y, hw_words);
start_op(RSA_MULT_START_REG);
Z->s = 1;
MBEDTLS_MPI_CHK( mbedtls_mpi_grow(Z, z_words) );
wait_op_complete(RSA_MULT_START_REG);
@ -509,6 +567,9 @@ int mbedtls_mpi_mul_mpi( mbedtls_mpi *Z, const mbedtls_mpi *X, const mbedtls_mpi
return ret;
}
/* Grow Z to result size early, avoid interim allocations */
MBEDTLS_MPI_CHK( mbedtls_mpi_grow(Z, z_words) );
/* If either factor is over 2048 bits, we can't use the standard hardware multiplier
(it assumes result is double longest factor, and result is max 4096 bits.)
@ -553,8 +614,6 @@ int mbedtls_mpi_mul_mpi( mbedtls_mpi *Z, const mbedtls_mpi *X, const mbedtls_mpi
start_op(RSA_MULT_START_REG);
MBEDTLS_MPI_CHK( mbedtls_mpi_grow(Z, z_words) );
wait_op_complete(RSA_MULT_START_REG);
/* Read back the result */
@ -661,9 +720,6 @@ static int mpi_mult_mpi_overlong(mbedtls_mpi *Z, const mbedtls_mpi *X, const mbe
};
mbedtls_mpi_init(&Ztemp);
/* Grow Z to result size early, avoid interim allocations */
mbedtls_mpi_grow(Z, z_words);
/* Get result Ztemp = Yp * X (need temporary variable Ztemp) */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi(&Ztemp, X, &Yp) );