Merge branch 'bugfix/sae_pk_improvements' into 'master'

wpa_supplicant: fixes in mbedtls porting to parse compressed EC public key and remove unnecessary code

See merge request espressif/esp-idf!23440
This commit is contained in:
Jiang Jiang Jian 2023-05-04 16:06:51 +08:00
commit 39e93a95a3
3 changed files with 14 additions and 265 deletions

View File

@ -317,7 +317,7 @@ typedef struct {
uint32_t transition_disable:1; /**< Whether to enable transition disable feature */
uint32_t reserved:26; /**< Reserved for future feature set */
wifi_sae_pwe_method_t sae_pwe_h2e; /**< Configuration for SAE PWE derivation method */
wifi_sae_pk_mode_t sae_pk_mode; /**< SAE-PK mode */
wifi_sae_pk_mode_t sae_pk_mode; /**< Configuration for SAE-PK (Public Key) Authentication method */
uint8_t failure_retry_cnt; /**< Number of connection retries station will do before moving to next AP. scan_method should be set as WIFI_ALL_CHANNEL_SCAN to use this config.
Note: Enabling this may cause connection time to increase incase best AP doesn't behave properly. */
uint32_t he_dcm_set:1; /**< Whether DCM max.constellation for transmission and reception is set. */

@ -1 +1 @@
Subproject commit 6292339dd1f262ec0bf9bb058758dbf02e1e0505
Subproject commit 4b8a58a5ddc673b460602ec4267611c4d08a6eeb

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@ -1222,273 +1222,22 @@ cleanup:
return sh_secret;
}
static int crypto_ec_key_load_group_from_der_params(mbedtls_asn1_buf *params, mbedtls_ecp_group *group)
{
if (params == NULL) {
return -1;
}
mbedtls_ecp_group_id grp_id;
if (params->tag == MBEDTLS_ASN1_OID) {
if (mbedtls_oid_get_ec_grp(params, &grp_id) != 0) {
return -1;
}
} else {
return -1;
}
if (group->id != MBEDTLS_ECP_DP_NONE && group->id != grp_id) {
return -1;
}
if (mbedtls_ecp_group_load(group, grp_id) != 0) {
return -1;
}
return 0;
}
static bool crypto_ec_key_is_compressed(const u8 *der, size_t der_len)
{
size_t len;
size_t prime_len;
const unsigned char *end = der + der_len;
const unsigned char *p;
*(const unsigned char **)&p = der;
if (mbedtls_asn1_get_tag((unsigned char **)&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE) != 0) {
return false;
}
end = p + len;
mbedtls_asn1_buf alg_oid;
mbedtls_asn1_buf params;
memset(&params, 0, sizeof(mbedtls_asn1_buf));
if (mbedtls_asn1_get_alg((unsigned char **)&p, end, &alg_oid, &params) != 0) {
return false;
}
if (mbedtls_asn1_get_bitstring_null((unsigned char **)&p, end, &len) != 0) {
return false;
}
mbedtls_ecp_group *group = os_malloc(sizeof(mbedtls_ecp_group));
if (!group) {
return false;
}
mbedtls_ecp_group_init(group);
if (crypto_ec_key_load_group_from_der_params(&params, group) != 0) {
goto _err;
}
prime_len = mbedtls_mpi_size(&group->P);
if (mbedtls_ecp_get_type(group) == MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS
&& (end - p) == 1+prime_len
&& (*p == 0x02 || *p == 0x03)) {
mbedtls_ecp_group_free(group);
os_free(group);
return true;
}
_err:
mbedtls_ecp_group_free(group);
os_free(group);
return false;
}
/* See https://github.com/Mbed-TLS/mbedtls/pull/6282 and https://github.com/mwarning/mbedtls_ecp_compression for more details*/
static struct crypto_ec_key* crypto_ec_key_parse_compressed_pub(const u8 *der, size_t der_len)
{
mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
const mbedtls_pk_info_t *pk_info;
mbedtls_pk_context *pkey = NULL;
int ret;
size_t len;
size_t prime_len;
const unsigned char *end = der + der_len;
const unsigned char *p;
*(const unsigned char **)&p = der;
int parity_bit;
if ((ret = mbedtls_asn1_get_tag((unsigned char **)&p, end, &len,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
return NULL;
}
end = p + len;
mbedtls_asn1_buf alg_oid;
mbedtls_asn1_buf params;
memset(&params, 0, sizeof(mbedtls_asn1_buf));
if ((ret = mbedtls_asn1_get_alg((unsigned char **)&p, end, &alg_oid, &params)) != 0) {
return NULL;
}
if (mbedtls_oid_get_pk_alg(&alg_oid, &pk_alg) != 0) {
return NULL;
}
if ((ret = mbedtls_asn1_get_bitstring_null((unsigned char **)&p, end, &len)) != 0) {
return NULL;
}
if (p + len != end) {
return NULL;
}
if ((pk_info = mbedtls_pk_info_from_type(pk_alg)) == NULL) {
return NULL;
}
if (!(pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH)) {
return NULL;
}
mbedtls_ecp_group *group = os_malloc(sizeof(mbedtls_ecp_group));
if (!group) {
return NULL;
}
mbedtls_ecp_group_init(group);
if ((ret = crypto_ec_key_load_group_from_der_params(&params, group)) != 0) {
mbedtls_ecp_group_free(group);
os_free(group);
return NULL;
}
/* Check prerequisite p = 3 mod 4 */
if (mbedtls_mpi_get_bit(&group->P, 0) != 1 ||
mbedtls_mpi_get_bit(&group->P, 1) != 1) {
mbedtls_ecp_group_free(group);
os_free(group);
return NULL;
}
prime_len = mbedtls_mpi_size(&group->P);
unsigned char *new_der = os_malloc(sizeof(unsigned char)*(der_len+prime_len));
if (!new_der) {
mbedtls_ecp_group_free(group);
os_free(group);
return NULL;
}
os_memcpy(new_der, der, der_len);
int offset = p - (unsigned char *)der ;
unsigned char *key_start = (unsigned char *)new_der + offset;
unsigned int new_der_len = der_len + prime_len;
mbedtls_mpi y;
mbedtls_mpi x;
mbedtls_mpi n;
mbedtls_mpi_init(&y);
mbedtls_mpi_init(&x);
mbedtls_mpi_init(&n);
MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&x, key_start + 1, prime_len));
parity_bit = key_start[0] & 1;
/* w = y^2 = x^3 + ax + b
* y = sqrt(w) = w^((p+1)/4) mod p (for prime p where p = 3 mod 4)
* use y to store intermediate results*/
/* y = x^2 */
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&y, &x, &x));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&y, &y, &group->P));
/* y = x^2 + a */
if (group->A.MBEDTLS_PRIVATE(p) == NULL) {
MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&n, -3));
MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&y, &y, &n));
} else {
MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&y, &y, &group->A));
}
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&y, &y, &group->P));
/* y = x^3 + ax */
MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&y, &y, &x));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&y, &y, &group->P));
/* y = x^3 + ax + b */
MBEDTLS_MPI_CHK(mbedtls_mpi_add_mpi(&y, &y, &group->B));
MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&y, &y, &group->P));
/* n = P + 1 */
MBEDTLS_MPI_CHK(mbedtls_mpi_add_int(&n, &group->P, 1));
/* n = (P + 1) / 4 */
MBEDTLS_MPI_CHK(mbedtls_mpi_shift_r(&n, 2));
/* y ^ ((P + 1) / 4) (mod p) */
MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&y, &y, &n, &group->P, NULL));
/* check parity bit match or else invert Y */
/* This quick inversion implementation is valid because Y != 0 for all
* Short Weierstrass curves supported by mbedtls, as each supported curve
* has an order that is a large prime, so each supported curve does not
* have any point of order 2, and a point with Y == 0 would be of order 2 */
if (mbedtls_mpi_get_bit(&y, 0) != parity_bit) {
/* y = p - y */
MBEDTLS_MPI_CHK(mbedtls_mpi_sub_mpi(&y, &group->P, &y));
}
/* y => output */
ret = mbedtls_mpi_write_binary(&y, key_start + 1 + prime_len, prime_len);
key_start[0] = 0x04;
pkey = os_zalloc(sizeof(*pkey));
if (!pkey) {
goto cleanup;
}
mbedtls_pk_init(pkey);
mbedtls_pk_setup(pkey, pk_info);
mbedtls_ecp_group_copy(&mbedtls_pk_ec(*pkey)->MBEDTLS_PRIVATE(grp), (const mbedtls_ecp_group *)group);
if ((ret = mbedtls_ecp_point_read_binary(group, &mbedtls_pk_ec(*pkey)->MBEDTLS_PRIVATE(Q),
(const unsigned char *)key_start, (new_der + new_der_len - key_start))) == 0) {
ret = mbedtls_ecp_check_pubkey(&mbedtls_pk_ec(*pkey)->MBEDTLS_PRIVATE(grp), &mbedtls_pk_ec(*pkey)->MBEDTLS_PRIVATE(Q));
}
if (ret < 0) {
wpa_printf(MSG_ERROR, "failed to parse ec public key");
mbedtls_ecp_group_free(group);
os_free(group);
os_free(new_der);
mbedtls_pk_free(pkey);
os_free(pkey);
return NULL;
}
cleanup:
mbedtls_mpi_free(&y);
mbedtls_mpi_free(&x);
mbedtls_mpi_free(&n);
mbedtls_ecp_group_free(group);
os_free(group);
os_free(new_der);
return (struct crypto_ec_key *)pkey;
}
struct crypto_ec_key *crypto_ec_key_parse_pub(const u8 *der, size_t der_len)
{
mbedtls_pk_context *pkey = NULL;
int ret;
mbedtls_pk_context *pkey = os_zalloc(sizeof(*pkey));
if (crypto_ec_key_is_compressed(der, der_len)) {
pkey = (mbedtls_pk_context *)crypto_ec_key_parse_compressed_pub(der, der_len);
if (!pkey) {
wpa_printf(MSG_ERROR, "failed to parse ec public key");
return NULL;
}
} else {
wpa_printf(MSG_ERROR, "failed to parse ec public key. expected compressed format");
if (!pkey) {
return NULL;
}
mbedtls_pk_init(pkey);
ret = mbedtls_pk_parse_public_key(pkey, der, der_len);
if (ret < 0) {
wpa_printf(MSG_ERROR, "failed to parse ec public key");
os_free(pkey);
return NULL;
}
return (struct crypto_ec_key *)pkey;