Validate EC_PARAMS for EdDSA keys

Signed-off-by: Jakub Jelen <jjelen@redhat.com>

diff --git a/lib/gnutls.asn b/lib/gnutls.asn
index b3adae054d9e78fd14d364ec71d1fa97eb3d8ba8..aca39fd2966806f03b9a346903344adc8bf45efd 100644 (file)
--- a/lib/gnutls.asn
+++ b/lib/gnutls.asn
@@ -90,6 +90,14 @@ DHParameter ::= SEQUENCE {
   privateValueLength  INTEGER OPTIONAL 
 }
 
+-- From PKCS #11 3.0
+pkcs-11-ec-Parameters ::= CHOICE {
+  --ecParameters   ECParameters,
+  oId              OBJECT IDENTIFIER,
+  --implicitlyCA   NULL,
+  curveName        PrintableString
+}
+
 -- ECC from RFC5480
 ECParameters ::= CHOICE {
   namedCurve         OBJECT IDENTIFIER

diff --git a/lib/gnutls_asn1_tab.c b/lib/gnutls_asn1_tab.c
index f5c88e1abf7a7a7f1f9b0a6781b167f79d972b08..0f566195598bb9f48244838fcf442778ba38728d 100644 (file)
--- a/lib/gnutls_asn1_tab.c
+++ b/lib/gnutls_asn1_tab.c
@@ -58,6 +58,9 @@ const asn1_static_node gnutls_asn1_tab[] = {
   { "prime", 1073741827, NULL },
   { "base", 1073741827, NULL },
   { "privateValueLength", 16387, NULL },
+  { "pkcs-11-ec-Parameters", 1610612754, NULL },
+  { "oId", 1073741836, NULL },
+  { "curveName", 31, NULL },
   { "ECParameters", 1610612754, NULL },
   { "namedCurve", 12, NULL },
   { "ECPrivateKey", 1610612741, NULL },

diff --git a/lib/pubkey.c b/lib/pubkey.c
index 50214b2991db2349b859b3a4c5c09618a4d2711c..de95a04c3758850d035c1de9b011f52132fb1463 100644 (file)
--- a/lib/pubkey.c
+++ b/lib/pubkey.c
@@ -362,6 +362,111 @@ gnutls_pubkey_get_preferred_hash_algorithm(gnutls_pubkey_t key,
 
 #ifdef ENABLE_PKCS11
 
+/* The EC_PARAMS attribute can contain either printable string with curve name
+ * or OID defined in RFC 8410 */
+static int
+gnutls_pubkey_parse_ecc_eddsa_params(const gnutls_datum_t *parameters,
+                                    gnutls_ecc_curve_t *outcurve)
+{
+       gnutls_ecc_curve_t curve = GNUTLS_ECC_CURVE_INVALID;
+       ASN1_TYPE asn1 = ASN1_TYPE_EMPTY;
+       unsigned int etype = ASN1_ETYPE_INVALID;
+       char str[MAX_OID_SIZE];
+       int str_size;
+       int ret;
+
+       ret = asn1_create_element(_gnutls_get_gnutls_asn(),
+                                 "GNUTLS.pkcs-11-ec-Parameters", &asn1);
+       if (ret != ASN1_SUCCESS) {
+               gnutls_assert();
+               return _gnutls_asn2err(ret);
+       }
+
+       ret = asn1_der_decoding(&asn1, parameters->data, parameters->size,
+                               NULL);
+       if (ret != ASN1_SUCCESS) {
+               gnutls_assert();
+               ret = _gnutls_asn2err(ret);
+               goto cleanup;
+       }
+
+       /* Read the type of choice.
+        */
+       str_size = sizeof(str) - 1;
+       ret = asn1_read_value(asn1, "", str, &str_size);
+       if (ret != ASN1_SUCCESS) {
+               gnutls_assert();
+               ret = _gnutls_asn2err(ret);
+               goto cleanup;
+       }
+       str[str_size] = 0;
+
+       /* Convert the choice to enum type */
+       if (strcmp(str, "oId") == 0) {
+               etype = ASN1_ETYPE_OBJECT_ID;
+       } else if (strcmp(str, "curveName") == 0) {
+               etype = ASN1_ETYPE_PRINTABLE_STRING;
+       }
+
+       str_size = sizeof(str) - 1;
+       switch (etype) {
+       case ASN1_ETYPE_OBJECT_ID:
+               ret = asn1_read_value(asn1, "oId", str, &str_size);
+               if (ret != ASN1_SUCCESS) {
+                       gnutls_assert();
+                       ret = _gnutls_asn2err(ret);
+                       break;
+               }
+
+               curve = gnutls_oid_to_ecc_curve(str);
+               if (curve != GNUTLS_ECC_CURVE_ED25519 &&
+                   curve != GNUTLS_ECC_CURVE_ED448) {
+                       _gnutls_debug_log("Curve %s is not supported for EdDSA\n", str);
+                       gnutls_assert();
+                       curve = GNUTLS_ECC_CURVE_INVALID;
+                       ret = GNUTLS_E_ECC_UNSUPPORTED_CURVE;
+                       break;
+               }
+
+               ret = GNUTLS_E_SUCCESS;
+               break;
+
+       case ASN1_ETYPE_PRINTABLE_STRING:
+               ret = asn1_read_value(asn1, "curveName", str, &str_size);
+               if (ret != ASN1_SUCCESS) {
+                       gnutls_assert();
+                       ret = _gnutls_asn2err(ret);
+                       break;
+               }
+
+               if (str_size == strlen("edwards25519") &&
+                   strncmp(str, "edwards25519", str_size) == 0) {
+                       curve = GNUTLS_ECC_CURVE_ED25519;
+                       ret = GNUTLS_E_SUCCESS;
+                       break;
+               } else if (str_size == strlen("edwards448") &&
+                          strncmp(str, "edwards448", str_size) == 0) {
+                       curve = GNUTLS_ECC_CURVE_ED448;
+                       ret = GNUTLS_E_SUCCESS;
+                       break;
+               }
+               /* FALLTHROUGH */
+
+       default:
+               /* Neither of CHOICEs found. Fail */
+               gnutls_assert();
+               ret = GNUTLS_E_ECC_UNSUPPORTED_CURVE;
+               curve = GNUTLS_ECC_CURVE_INVALID;
+               break;
+       }
+
+
+      cleanup:
+       asn1_delete_structure(&asn1);
+       *outcurve = curve;
+       return ret;
+}
+
 
 static int
 gnutls_pubkey_import_ecc_eddsa(gnutls_pubkey_t key,
@@ -369,10 +474,14 @@ gnutls_pubkey_import_ecc_eddsa(gnutls_pubkey_t key,
                               const gnutls_datum_t * ecpoint)
 {
        int ret;
+
+       gnutls_ecc_curve_t curve = GNUTLS_ECC_CURVE_INVALID;
        gnutls_datum_t raw_point = {NULL, 0};
 
-       /* TODO handle parameters containing curve name to figure
-        * out if it is Ed25519, Ed448 or even something else */
+       ret = gnutls_pubkey_parse_ecc_eddsa_params(parameters, &curve);
+       if (ret < 0) {
+               return gnutls_assert_val(ret);
+       }
 
        ret = _gnutls_x509_decode_string(ASN1_ETYPE_OCTET_STRING,
                                         ecpoint->data, ecpoint->size,
@@ -382,8 +491,7 @@ gnutls_pubkey_import_ecc_eddsa(gnutls_pubkey_t key,
                gnutls_free(raw_point.data);
                return ret;
        }
-       ret = gnutls_pubkey_import_ecc_raw(key, GNUTLS_ECC_CURVE_ED25519,
-                                          &raw_point, NULL);
+       ret = gnutls_pubkey_import_ecc_raw(key, curve, &raw_point, NULL);
 
        gnutls_free(raw_point.data);
        return ret;