psa: remove bits_is_sloppy parameter from mbedtls_ecc_group_from_psa()
Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/psa_crypto_ecp.c b/library/psa_crypto_ecp.c
index 3f2ec23..20ef29c 100644
--- a/library/psa_crypto_ecp.c
+++ b/library/psa_crypto_ecp.c
@@ -41,6 +41,7 @@
psa_status_t status;
mbedtls_ecp_keypair *ecp = NULL;
size_t curve_bytes = data_length;
+ size_t curve_bits_check;
int explicit_bits = (curve_bits != 0);
if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type) &&
@@ -84,7 +85,7 @@
/* Load the group. */
grp_id = mbedtls_ecc_group_from_psa(PSA_KEY_TYPE_ECC_GET_FAMILY(type),
- curve_bits, !explicit_bits);
+ curve_bits);
if (grp_id == MBEDTLS_ECP_DP_NONE) {
/* We can't distinguish between a nonsensical family/size combination
* (which would warrant PSA_ERROR_INVALID_ARGUMENT) and a
@@ -96,6 +97,17 @@
goto exit;
}
+ /* Get the exact number of bits which are necessary for this key. This is
+ * used to validate the "curve_bits" input parameter (only in case it was
+ * provided).
+ * Note: we intentionally ignore the return value of mbedtls_ecc_group_to_psa()
+ * because we are only interested in the curve's bit size. */
+ mbedtls_ecc_group_to_psa(grp_id, &curve_bits_check);
+ if (explicit_bits && (curve_bits_check != curve_bits)) {
+ status = PSA_ERROR_NOT_SUPPORTED;
+ goto exit;
+ }
+
status = mbedtls_to_psa_error(
mbedtls_ecp_group_load(&ecp->grp, grp_id));
if (status != PSA_SUCCESS) {
@@ -285,7 +297,7 @@
psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY(
attributes->core.type);
mbedtls_ecp_group_id grp_id =
- mbedtls_ecc_group_from_psa(curve, attributes->core.bits, 0);
+ mbedtls_ecc_group_from_psa(curve, attributes->core.bits);
const mbedtls_ecp_curve_info *curve_info =
mbedtls_ecp_curve_info_from_grp_id(grp_id);