commit e77307738d04c712a702988a72a51ffcc7167031
author Valerio Setti <valerio.setti@nordicsemi.no> Wed Jun 21 16:58:40 2023 +0200
committer Valerio Setti <valerio.setti@nordicsemi.no> Thu Jun 29 14:33:26 2023 +0200
tree 3054fb2c435bd94f269cdf9de745e2650b8bc1d0
parent ed7d6af67026cf7b89a9e1a24087f8f75ce8f955

pk_wrap: add support for ECDSA verify for opaque keys

This commit also add tests to verify the functionality

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>

library/pk_wrap.c

diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 75904c4..4f7094a 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -781,6 +781,36 @@
     return ret;
 }
 
+static int ecdsa_verify_wrap_opaque(mbedtls_pk_context *pk,
+                                    mbedtls_md_type_t md_alg,
+                                    const unsigned char *hash, size_t hash_len,
+                                    const unsigned char *sig, size_t sig_len)
+{
+    (void) md_alg;
+    unsigned char key[MBEDTLS_PK_MAX_EC_PUBKEY_RAW_LEN];
+    size_t key_len;
+    psa_key_attributes_t key_attr = PSA_KEY_ATTRIBUTES_INIT;
+    psa_ecc_family_t curve;
+    size_t curve_bits;
+    psa_status_t status;
+
+    status = psa_get_key_attributes(pk->priv_id, &key_attr);
+    if (status != PSA_SUCCESS) {
+        return PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
+    }
+    curve = PSA_KEY_TYPE_ECC_GET_FAMILY(psa_get_key_type(&key_attr));
+    curve_bits = psa_get_key_bits(&key_attr);
+    psa_reset_key_attributes(&key_attr);
+
+    status = psa_export_public_key(pk->priv_id, key, sizeof(key), &key_len);
+    if (status != PSA_SUCCESS) {
+        return PSA_PK_ECDSA_TO_MBEDTLS_ERR(status);
+    }
+
+    return ecdsa_verify_psa(key, key_len, curve, curve_bits,
+                            hash, hash_len, sig, sig_len);
+}
+
 #if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
 static int ecdsa_verify_wrap(mbedtls_pk_context *pk,
                              mbedtls_md_type_t md_alg,
@@ -1757,7 +1787,7 @@
     "Opaque",
     pk_opaque_get_bitlen,
     pk_opaque_ecdsa_can_do,
-    NULL, /* verify - will be done later */
+    ecdsa_verify_wrap_opaque,
     ecdsa_sign_wrap_opaque,
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     NULL, /* restartable verify - not relevant */

tests/suites/test_suite_pk.function

diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 4074e13..a204841 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -223,8 +223,6 @@
     mbedtls_pk_init(&pk2);
     USE_PSA_INIT();
 
-    TEST_ASSERT(psa_crypto_init() == PSA_SUCCESS);
-
     TEST_ASSERT(mbedtls_pk_setup_opaque(&pk, MBEDTLS_SVC_KEY_ID_INIT) ==
                 MBEDTLS_ERR_PK_BAD_INPUT_DATA);
 
@@ -261,10 +259,11 @@
     }
 
     /* unsupported operations: verify, decrypt, encrypt */
-    TEST_ASSERT(mbedtls_pk_verify(&pk, md_alg,
-                                  b1, sizeof(b1), b2, sizeof(b2))
-                == MBEDTLS_ERR_PK_TYPE_MISMATCH);
-    if (key_is_rsa == 0) {
+    if (key_is_rsa == 1) {
+        TEST_ASSERT(mbedtls_pk_verify(&pk, md_alg,
+                                      b1, sizeof(b1), b2, sizeof(b2))
+                    == MBEDTLS_ERR_PK_TYPE_MISMATCH);
+    } else {
         TEST_ASSERT(mbedtls_pk_decrypt(&pk, b1, sizeof(b1),
                                        b2, &len, sizeof(b2),
                                        NULL, NULL)
@@ -1367,6 +1366,11 @@
     TEST_ASSERT(mbedtls_pk_sign(&pk, MBEDTLS_MD_SHA256,
                                 hash, sizeof(hash), sig, sizeof(sig), &sig_len,
                                 NULL, NULL) == 0);
+    /* Only opaque EC keys support verification. */
+    if (PSA_KEY_TYPE_IS_ECC_KEY_PAIR(psa_type_arg)) {
+        TEST_ASSERT(mbedtls_pk_verify(&pk, MBEDTLS_MD_SHA256,
+                                      hash, sizeof(hash), sig, sig_len) == 0);
+    }
 
     /* Export underlying public key for re-importing in a psa context. */
 #if defined(MBEDTLS_PK_WRITE_C)