Implement support for ec point compression query

OpenSSL TLS code needs to know if the EC public key is in compressed or uncompressed representation, for peer keys. Add support to return this information from public keys. Signed-off-by: Simo Sorce <[email protected]>
simo5 · Sep 27, 2024 · feea088 · feea088
1 parent 3bb0fa5
commit feea088
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Showing 3 changed files with 29 additions and 1 deletion.
diff --git a/src/keymgmt.c b/src/keymgmt.c
@@ -1640,6 +1640,18 @@ static int p11prov_ec_get_params(void *keydata, OSSL_PARAM params[])
             memcpy(p->data, pub_key->pValue, pub_key->ulValueLen);
         }
     }
+    p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT);
+    if (p) {
+        bool compressed = p11prov_obj_get_ec_compressed(key);
+        if (compressed) {
+            ret = OSSL_PARAM_set_utf8_string(p, "compressed");
+        } else {
+            ret = OSSL_PARAM_set_utf8_string(p, "uncompressed");
+        }
+        if (ret != RET_OSSL_OK) {
+            return ret;
+        }
+    }
 
     return RET_OSSL_OK;
 }
@@ -1655,10 +1667,11 @@ static const OSSL_PARAM *p11prov_ec_gettable_params(void *provctx)
         OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_PUB_X, NULL, 0),
         OSSL_PARAM_BN(OSSL_PKEY_PARAM_EC_PUB_Y, NULL, 0),
         OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_ENCODED_PUBLIC_KEY, NULL, 0),
+        OSSL_PARAM_utf8_string(OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT, NULL,
+                               0),
         /*
          * OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAM
          * OSSL_PKEY_PARAM_EC_ENCODING
-         * OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT
          * OSSL_PKEY_PARAM_EC_FIELD_TYPE
          * OSSL_PKEY_PARAM_EC_P
          * OSSL_PKEY_PARAM_EC_A

diff --git a/src/objects.c b/src/objects.c
@@ -1728,6 +1728,20 @@ const char *p11prov_obj_get_ec_group_name(P11PROV_OBJ *obj)
     return (const char *)attr->pValue;
 }
 
+bool p11prov_obj_get_ec_compressed(P11PROV_OBJ *obj)
+{
+    CK_ATTRIBUTE *pub_key;
+    uint8_t *buf;
+
+    pub_key = p11prov_obj_get_attr(obj, CKA_P11PROV_PUB_KEY);
+    if (!pub_key) {
+        return false;
+    }
+    buf = pub_key->pValue;
+
+    return (buf[0] & 0x01) == 0x01;
+}
+
 static int ossl_param_construct_bn(P11PROV_CTX *provctx, OSSL_PARAM *param,
                                    const char *key, const BIGNUM *val)
 {

diff --git a/src/objects.h b/src/objects.h
@@ -52,6 +52,7 @@ CK_RV p11prov_obj_set_attributes(P11PROV_CTX *ctx, P11PROV_SESSION *session,
                                  P11PROV_OBJ *obj, CK_ATTRIBUTE *template,
                                  CK_ULONG tsize);
 const char *p11prov_obj_get_ec_group_name(P11PROV_OBJ *obj);
+bool p11prov_obj_get_ec_compressed(P11PROV_OBJ *obj);
 int p11prov_obj_export_public_key(P11PROV_OBJ *obj, CK_KEY_TYPE key_type,
                                   bool search_related, OSSL_CALLBACK *cb_fn,
                                   void *cb_arg);