pk: fix alg selection in mbedtls_pk_sign_ext() for opaque keys
This commit also fixes pk_psa_wrap_sign_ext() setting the RSA padding
mode so that mbedtls_pk_get_psa_attributes() correctly guesses
the PSA alg to be used.
Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/pk.c b/library/pk.c
index 7aee940..8a5124f 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -1188,9 +1188,32 @@
}
if (mbedtls_pk_get_type(ctx) == MBEDTLS_PK_OPAQUE) {
+ psa_key_attributes_t key_attr = PSA_KEY_ATTRIBUTES_INIT;
+ psa_algorithm_t psa_alg, psa_enrollment_alg, sign_alg;
psa_status_t status;
- status = psa_sign_hash(ctx->priv_id, PSA_ALG_RSA_PSS(psa_md_alg),
+ status = psa_get_key_attributes(ctx->priv_id, &key_attr);
+ if (status != PSA_SUCCESS) {
+ return PSA_PK_RSA_TO_MBEDTLS_ERR(status);
+ }
+ psa_alg = psa_get_key_algorithm(&key_attr);
+ psa_enrollment_alg = psa_get_key_enrollment_algorithm(&key_attr);
+ psa_reset_key_attributes(&key_attr);
+
+ /* Since we're PK type is MBEDTLS_PK_RSASSA_PSS at least one between
+ * alg and enrollment alg should be of type RSA_PSS. */
+ if (PSA_ALG_IS_RSA_PSS(psa_alg)) {
+ sign_alg = psa_alg;
+ } else if (PSA_ALG_IS_RSA_PSS(psa_enrollment_alg)) {
+ sign_alg = psa_enrollment_alg;
+ } else {
+ /* The opaque key has no RSA PSS algorithm associated. */
+ return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+ }
+ /* Adjust the hashing algorithm. */
+ sign_alg = (sign_alg & ~PSA_ALG_HASH_MASK) | PSA_ALG_GET_HASH(psa_md_alg);
+
+ status = psa_sign_hash(ctx->priv_id, sign_alg,
hash, hash_len,
sig, sig_size, sig_len);
return PSA_PK_RSA_TO_MBEDTLS_ERR(status);