esp-idf/components/mbedtls/port/ecdsa/ecdsa_alt.c
Mahavir Jain f434d21f4a fix(ecdsa): remove unused k_mode from the ECDSA HAL/LL API
For ESP32-H2 case, the hardware k mode is always enforced through
efuse settings (done in startup code).

For ESP32-P4 case, the software k mode is not supported in the peripheral
itself and code was redundant.
2023-11-17 07:13:53 +00:00

514 lines
18 KiB
C

/*
* SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <string.h>
#include "hal/ecdsa_ll.h"
#include "hal/ecdsa_hal.h"
#include "esp_crypto_lock.h"
#include "esp_efuse.h"
#include "esp_private/esp_crypto_lock_internal.h"
#include "mbedtls/error.h"
#include "mbedtls/ecdsa.h"
#include "mbedtls/asn1write.h"
#include "mbedtls/platform_util.h"
#include "ecdsa/ecdsa_alt.h"
#define ECDSA_KEY_MAGIC (short) 0xECD5A
#define ECDSA_SHA_LEN 32
#define MAX_ECDSA_COMPONENT_LEN 32
__attribute__((unused)) static const char *TAG = "ecdsa_alt";
static void esp_ecdsa_acquire_hardware(void)
{
esp_crypto_ecdsa_lock_acquire();
ECDSA_RCC_ATOMIC() {
ecdsa_ll_enable_bus_clock(true);
ecdsa_ll_reset_register();
}
}
static void esp_ecdsa_release_hardware(void)
{
ECDSA_RCC_ATOMIC() {
ecdsa_ll_enable_bus_clock(false);
}
esp_crypto_ecdsa_lock_release();
}
static void ecdsa_be_to_le(const uint8_t* be_point, uint8_t *le_point, uint8_t len)
{
/* When the size is 24 bytes, it should be padded with 0 bytes*/
memset(le_point, 0x0, 32);
for(int i = 0; i < len; i++) {
le_point[i] = be_point[len - i - 1];
}
}
#ifdef SOC_ECDSA_SUPPORT_EXPORT_PUBKEY
int esp_ecdsa_load_pubkey(mbedtls_ecp_keypair *keypair, int efuse_blk)
{
int ret = -1;
if (efuse_blk < EFUSE_BLK_KEY0 || efuse_blk >= EFUSE_BLK_KEY_MAX) {
ESP_LOGE(TAG, "Invalid efuse block selected");
return ret;
}
ecdsa_curve_t curve;
esp_efuse_block_t blk;
uint16_t len;
uint8_t zeroes[MAX_ECDSA_COMPONENT_LEN] = {0};
uint8_t qx_le[MAX_ECDSA_COMPONENT_LEN];
uint8_t qy_le[MAX_ECDSA_COMPONENT_LEN];
if (keypair->MBEDTLS_PRIVATE(grp).id == MBEDTLS_ECP_DP_SECP192R1) {
curve = ECDSA_CURVE_SECP192R1;
len = 24;
} else if (keypair->MBEDTLS_PRIVATE(grp).id == MBEDTLS_ECP_DP_SECP256R1) {
curve = ECDSA_CURVE_SECP256R1;
len = 32;
} else {
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
if (!esp_efuse_find_purpose(ESP_EFUSE_KEY_PURPOSE_ECDSA_KEY, &blk)) {
ESP_LOGE(TAG, "No efuse block with purpose ECDSA_KEY found");
return MBEDTLS_ERR_ECP_INVALID_KEY;
}
ecdsa_hal_config_t conf = {
.mode = ECDSA_MODE_EXPORT_PUBKEY,
.curve = curve,
.use_km_key = 0, //TODO: IDF-7992
.efuse_key_blk = efuse_blk,
};
esp_ecdsa_acquire_hardware();
do {
ecdsa_hal_export_pubkey(&conf, qx_le, qy_le, len);
} while (!memcmp(qx_le, zeroes, len) || !memcmp(qy_le, zeroes, len));
esp_ecdsa_release_hardware();
MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary_le(&(keypair->MBEDTLS_PRIVATE(Q).MBEDTLS_PRIVATE(X)), qx_le, len));
MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary_le(&(keypair->MBEDTLS_PRIVATE(Q).MBEDTLS_PRIVATE(Y)), qy_le, len));
MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&(keypair->MBEDTLS_PRIVATE(Q).MBEDTLS_PRIVATE(Z)), 1));
return 0;
cleanup:
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
#endif /* SOC_ECDSA_SUPPORT_EXPORT_PUBKEY */
#ifdef CONFIG_MBEDTLS_HARDWARE_ECDSA_SIGN
int esp_ecdsa_privkey_load_mpi(mbedtls_mpi *key, int efuse_blk)
{
if (!key) {
ESP_LOGE(TAG, "Invalid memory");
return -1;
}
if (efuse_blk < EFUSE_BLK_KEY0 || efuse_blk >= EFUSE_BLK_KEY_MAX) {
ESP_LOGE(TAG, "Invalid efuse block");
return -1;
}
mbedtls_mpi_init(key);
/* We use the mbedtls_mpi struct to pass our own context to hardware ECDSA peripheral
* MPI struct expects `s` to be either 1 or -1, by setting it to 0xECD5A, we ensure that it does
* not collide with a valid MPI. This is done to differentiate between using the private key stored in efuse
* or using the private key provided by software
*
* `n` is used to store the efuse block which should be used as key
*/
key->MBEDTLS_PRIVATE(s) = ECDSA_KEY_MAGIC;
key->MBEDTLS_PRIVATE(n) = efuse_blk;
key->MBEDTLS_PRIVATE(p) = NULL;
return 0;
}
int esp_ecdsa_privkey_load_pk_context(mbedtls_pk_context *key_ctx, int efuse_blk)
{
const mbedtls_pk_info_t *pk_info;
mbedtls_ecp_keypair *keypair;
if (!key_ctx) {
ESP_LOGE(TAG, "Invalid memory");
return -1;
}
if (efuse_blk < EFUSE_BLK_KEY0 || efuse_blk >= EFUSE_BLK_KEY_MAX) {
ESP_LOGE(TAG, "Invalid efuse block");
return -1;
}
mbedtls_pk_init(key_ctx);
pk_info = mbedtls_pk_info_from_type(MBEDTLS_PK_ECDSA);
mbedtls_pk_setup(key_ctx, pk_info);
keypair = mbedtls_pk_ec(*key_ctx);
return esp_ecdsa_privkey_load_mpi(&(keypair->MBEDTLS_PRIVATE(d)), efuse_blk);
}
int esp_ecdsa_set_pk_context(mbedtls_pk_context *key_ctx, esp_ecdsa_pk_conf_t *conf)
{
int ret = -1;
if (!key_ctx) {
ESP_LOGE(TAG, "mbedtls_pk_context cannot be NULL");
return ret;
}
if (!conf) {
ESP_LOGE(TAG, "esp_ecdsa_pk_conf_t cannot be NULL");
return ret;
}
if (conf->grp_id != MBEDTLS_ECP_DP_SECP192R1 && conf->grp_id != MBEDTLS_ECP_DP_SECP256R1) {
ESP_LOGE(TAG, "Invalid EC curve group id mentioned in esp_ecdsa_pk_conf_t");
return ret;
}
if ((ret = esp_ecdsa_privkey_load_pk_context(key_ctx, conf->efuse_block)) != 0) {
ESP_LOGE(TAG, "Loading private key context failed, esp_ecdsa_privkey_load_pk_context() returned %d", ret);
return ret;
}
mbedtls_ecp_keypair *keypair = mbedtls_pk_ec(*key_ctx);
if ((ret = mbedtls_ecp_group_load(&(keypair->MBEDTLS_PRIVATE(grp)), conf->grp_id)) != 0) {
ESP_LOGE(TAG, "Loading ecp group failed, mbedtls_pk_ec() returned %d", ret);
return ret;
}
#ifdef SOC_ECDSA_SUPPORT_EXPORT_PUBKEY
if (conf->load_pubkey) {
if ((ret = esp_ecdsa_load_pubkey(keypair, conf->efuse_block)) != 0) {
ESP_LOGE(TAG, "Loading public key context failed, esp_ecdsa_load_pubkey() returned %d", ret);
return ret;
}
}
#endif
return 0;
}
static int esp_ecdsa_sign(mbedtls_ecp_group *grp, mbedtls_mpi* r, mbedtls_mpi* s,
const mbedtls_mpi *d, const unsigned char* msg, size_t msg_len)
{
ecdsa_curve_t curve;
esp_efuse_block_t blk;
uint16_t len;
uint8_t zeroes[MAX_ECDSA_COMPONENT_LEN] = {0};
uint8_t sha_le[ECDSA_SHA_LEN];
uint8_t r_le[MAX_ECDSA_COMPONENT_LEN];
uint8_t s_le[MAX_ECDSA_COMPONENT_LEN];
if (!grp || !r || !s || !d || !msg) {
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
if (msg_len != ECDSA_SHA_LEN) {
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
if (grp->id == MBEDTLS_ECP_DP_SECP192R1) {
curve = ECDSA_CURVE_SECP192R1;
len = 24;
} else if (grp->id == MBEDTLS_ECP_DP_SECP256R1) {
curve = ECDSA_CURVE_SECP256R1;
len = 32;
} else {
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
if (!esp_efuse_find_purpose(ESP_EFUSE_KEY_PURPOSE_ECDSA_KEY, &blk)) {
ESP_LOGE(TAG, "No efuse block with purpose ECDSA_KEY found");
return MBEDTLS_ERR_ECP_INVALID_KEY;
}
ecdsa_be_to_le(msg, sha_le, len);
esp_ecdsa_acquire_hardware();
do {
ecdsa_hal_config_t conf = {
.mode = ECDSA_MODE_SIGN_GEN,
.curve = curve,
.sha_mode = ECDSA_Z_USER_PROVIDED,
.efuse_key_blk = d->MBEDTLS_PRIVATE(n),
.use_km_key = 0, //TODO: IDF-7992
};
ecdsa_hal_gen_signature(&conf, sha_le, r_le, s_le, len);
} while (!memcmp(r_le, zeroes, len) || !memcmp(s_le, zeroes, len));
esp_ecdsa_release_hardware();
mbedtls_mpi_read_binary_le(r, r_le, len);
mbedtls_mpi_read_binary_le(s, s_le, len);
return 0;
}
/*
* Compute ECDSA signature of a hashed message;
*/
extern int __real_mbedtls_ecdsa_sign(mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
int __wrap_mbedtls_ecdsa_sign(mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
int __wrap_mbedtls_ecdsa_sign(mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
{
/*
* Check `d` whether it contains the hardware key
*/
if (d->MBEDTLS_PRIVATE(s) == ECDSA_KEY_MAGIC) {
// Use hardware ECDSA peripheral
return esp_ecdsa_sign(grp, r, s, d, buf, blen);
} else {
return __real_mbedtls_ecdsa_sign(grp, r, s, d, buf, blen, f_rng, p_rng);
}
}
extern int __real_mbedtls_ecdsa_sign_restartable(mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
int (*f_rng_blind)(void *, unsigned char *, size_t), void *p_rng_blind,
mbedtls_ecdsa_restart_ctx *rs_ctx);
int __wrap_mbedtls_ecdsa_sign_restartable(mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
int (*f_rng_blind)(void *, unsigned char *, size_t), void *p_rng_blind,
mbedtls_ecdsa_restart_ctx *rs_ctx);
int __wrap_mbedtls_ecdsa_sign_restartable(mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
int (*f_rng_blind)(void *, unsigned char *, size_t), void *p_rng_blind,
mbedtls_ecdsa_restart_ctx *rs_ctx)
{
/*
* Check `d` whether it contains the hardware key
*/
if (d->MBEDTLS_PRIVATE(s) == ECDSA_KEY_MAGIC) {
// Use hardware ECDSA peripheral
return esp_ecdsa_sign(grp, r, s, d, buf, blen);
} else {
return __real_mbedtls_ecdsa_sign_restartable(grp, r, s, d, buf, blen, f_rng, p_rng, f_rng_blind, p_rng_blind, rs_ctx);
}
}
int __real_mbedtls_ecdsa_write_signature_restartable(mbedtls_ecdsa_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t sig_size, size_t *slen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
mbedtls_ecdsa_restart_ctx *rs_ctx);
int __wrap_mbedtls_ecdsa_write_signature_restartable(mbedtls_ecdsa_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t sig_size, size_t *slen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
mbedtls_ecdsa_restart_ctx *rs_ctx);
/*
* Convert a signature (given by context) to ASN.1
*/
static int ecdsa_signature_to_asn1(const mbedtls_mpi *r, const mbedtls_mpi *s,
unsigned char *sig, size_t sig_size,
size_t *slen)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char buf[MBEDTLS_ECDSA_MAX_LEN] = { 0 };
// Setting the pointer p to the end of the buffer as the functions used afterwards write in backwards manner in the given buffer.
unsigned char *p = buf + sizeof(buf);
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_mpi(&p, buf, s));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_mpi(&p, buf, r));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&p, buf, len));
MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&p, buf,
MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE));
if (len > sig_size) {
return MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL;
}
memcpy(sig, p, len);
*slen = len;
return 0;
}
int __wrap_mbedtls_ecdsa_write_signature_restartable(mbedtls_ecdsa_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t sig_size, size_t *slen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
mbedtls_ecdsa_restart_ctx *rs_ctx)
{
if (ctx->MBEDTLS_PRIVATE(d).MBEDTLS_PRIVATE(s) != ECDSA_KEY_MAGIC) {
return __real_mbedtls_ecdsa_write_signature_restartable(ctx, md_alg, hash, hlen, sig, sig_size, slen, f_rng, p_rng, rs_ctx);
}
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_mpi r, s;
mbedtls_mpi_init(&r);
mbedtls_mpi_init(&s);
/*
* Check `d` whether it contains the hardware key
*/
if (ctx->MBEDTLS_PRIVATE(d).MBEDTLS_PRIVATE(s) == ECDSA_KEY_MAGIC) {
// Use hardware ECDSA peripheral
MBEDTLS_MPI_CHK(esp_ecdsa_sign(&ctx->MBEDTLS_PRIVATE(grp), &r, &s, &ctx->MBEDTLS_PRIVATE(d), hash, hlen));
}
MBEDTLS_MPI_CHK(ecdsa_signature_to_asn1(&r, &s, sig, sig_size, slen));
cleanup:
mbedtls_mpi_free(&r);
mbedtls_mpi_free(&s);
return ret;
}
int __wrap_mbedtls_ecdsa_write_signature(mbedtls_ecdsa_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t sig_size, size_t *slen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng);
int __wrap_mbedtls_ecdsa_write_signature(mbedtls_ecdsa_context *ctx,
mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hlen,
unsigned char *sig, size_t sig_size, size_t *slen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng)
{
return __wrap_mbedtls_ecdsa_write_signature_restartable(
ctx, md_alg, hash, hlen, sig, sig_size, slen,
f_rng, p_rng, NULL);
}
#endif /* CONFIG_MBEDTLS_HARDWARE_ECDSA_SIGN */
#ifdef CONFIG_MBEDTLS_HARDWARE_ECDSA_VERIFY
static int esp_ecdsa_verify(mbedtls_ecp_group *grp,
const unsigned char *buf, size_t blen,
const mbedtls_ecp_point *Q,
const mbedtls_mpi *r,
const mbedtls_mpi *s)
{
ecdsa_curve_t curve;
uint16_t len;
uint8_t r_le[MAX_ECDSA_COMPONENT_LEN];
uint8_t s_le[MAX_ECDSA_COMPONENT_LEN];
uint8_t qx_le[MAX_ECDSA_COMPONENT_LEN];
uint8_t qy_le[MAX_ECDSA_COMPONENT_LEN];
uint8_t sha_le[ECDSA_SHA_LEN];
if (!grp || !buf || !Q || !r || !s) {
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
if (blen != ECDSA_SHA_LEN) {
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
if (grp->id == MBEDTLS_ECP_DP_SECP192R1) {
curve = ECDSA_CURVE_SECP192R1;
len = 24;
} else if (grp->id == MBEDTLS_ECP_DP_SECP256R1) {
curve = ECDSA_CURVE_SECP256R1;
len = 32;
} else {
return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
}
if (mbedtls_mpi_cmp_int(r, 1) < 0 || mbedtls_mpi_cmp_mpi(r, &grp->N) >= 0 ||
mbedtls_mpi_cmp_int(s, 1) < 0 || mbedtls_mpi_cmp_mpi(s, &grp->N) >= 0 )
{
return MBEDTLS_ERR_ECP_VERIFY_FAILED;
}
ecdsa_be_to_le(buf, sha_le, len);
mbedtls_mpi_write_binary_le(&Q->MBEDTLS_PRIVATE(X), qx_le, len);
mbedtls_mpi_write_binary_le(&Q->MBEDTLS_PRIVATE(Y), qy_le, len);
mbedtls_mpi_write_binary_le(r, r_le, len);
mbedtls_mpi_write_binary_le(s, s_le, len);
esp_ecdsa_acquire_hardware();
ecdsa_hal_config_t conf = {
.mode = ECDSA_MODE_SIGN_VERIFY,
.curve = curve,
.sha_mode = ECDSA_Z_USER_PROVIDED,
};
int ret = ecdsa_hal_verify_signature(&conf, sha_le, r_le, s_le, qx_le, qy_le, len);
esp_ecdsa_release_hardware();
if (ret != 0) {
return MBEDTLS_ERR_ECP_VERIFY_FAILED;
}
return ret;
}
/*
* Verify ECDSA signature of hashed message
*/
extern int __real_mbedtls_ecdsa_verify(mbedtls_ecp_group *grp,
const unsigned char *buf, size_t blen,
const mbedtls_ecp_point *Q,
const mbedtls_mpi *r,
const mbedtls_mpi *s);
int __wrap_mbedtls_ecdsa_verify(mbedtls_ecp_group *grp,
const unsigned char *buf, size_t blen,
const mbedtls_ecp_point *Q,
const mbedtls_mpi *r,
const mbedtls_mpi *s);
int __wrap_mbedtls_ecdsa_verify(mbedtls_ecp_group *grp,
const unsigned char *buf, size_t blen,
const mbedtls_ecp_point *Q,
const mbedtls_mpi *r,
const mbedtls_mpi *s)
{
if (grp->id == MBEDTLS_ECP_DP_SECP192R1 || grp->id == MBEDTLS_ECP_DP_SECP256R1) {
return esp_ecdsa_verify(grp, buf, blen, Q, r, s);
} else {
return __real_mbedtls_ecdsa_verify(grp, buf, blen, Q, r, s);
}
}
#endif /* CONFIG_MBEDTLS_HARDWARE_ECDSA_VERIFY */