fix: make keypair generation async to avoid blocking the event loop

generate_keypair() used synchronous subprocess.run() which blocked
the NiceGUI event loop during wg genkey/pubkey calls. This caused
WebSocket disconnects, page reloads, and the config dialog never
appearing after device creation.

Switched to asyncio.create_subprocess_exec so the event loop stays
responsive while waiting for the wg CLI.

tests/e2e/test_devices.py

@@ -1,6 +1,6 @@
 """End-to-end tests for device management UI using NiceGUI's User fixture."""
 
-from unittest.mock import patch
+from unittest.mock import AsyncMock, patch
 
 import pytest
 from nicegui.testing import User
@@ -25,7 +25,7 @@ async def _login(user: User):
 @pytest.mark.parametrize("user", [{"storage": {}}], indirect=True)
 async def test_add_device_via_ui(user: User, test_user: UserModel):
     """Test the full flow: login → devices → add device → see it in table."""
-    with patch("wiregui.pages.devices.generate_keypair", return_value=(FAKE_PRIVATE_KEY, FAKE_PUBLIC_KEY)), \
+    with patch("wiregui.pages.devices.generate_keypair", new_callable=AsyncMock, return_value=(FAKE_PRIVATE_KEY, FAKE_PUBLIC_KEY)), \
          patch("wiregui.pages.devices.generate_preshared_key", return_value="cHJlc2hhcmVkMDAwMDAwMDAwMDAwMDAwMDAwMDAwMDA="):
 
         await _login(user)

tests/test_utils.py

@@ -103,7 +103,7 @@ def test_build_client_config_no_psk():
 # --- Crypto (only if wg is installed) ---
 
 
-def test_generate_keypair():
+async def test_generate_keypair():
     """Test keypair generation — requires `wg` CLI to be installed."""
     try:
         subprocess.run(["wg", "--version"], capture_output=True, check=True)
@@ -112,7 +112,7 @@ def test_generate_keypair():
 
     from wiregui.utils.crypto import generate_keypair, generate_preshared_key
 
-    priv, pub = generate_keypair()
+    priv, pub = await generate_keypair()
     assert len(priv) == 44  # base64-encoded 32 bytes
     assert len(pub) == 44
 

wiregui/api/v0/devices.py

@@ -54,7 +54,7 @@ async def create_device(
     settings = get_settings()
     owner_id = body.user_id if (body.user_id and current_user.role == "admin") else current_user.id
 
-    _private_key, public_key = generate_keypair()
+    _private_key, public_key = await generate_keypair()
     psk = generate_preshared_key()
     ipv4 = await allocate_ipv4(session, settings.wg_ipv4_network)
     ipv6 = await allocate_ipv6(session, settings.wg_ipv6_network)

wiregui/auth/seed.py

@@ -51,7 +51,7 @@ async def ensure_server_keypair() -> None:
             return  # already have keys
 
         try:
-            private_key, public_key = generate_keypair()
+            private_key, public_key = await generate_keypair()
             config.server_private_key = private_key
             config.server_public_key = public_key
             session.add(config)

wiregui/pages/admin/devices.py

@@ -88,7 +88,7 @@ async def admin_devices_page():
 
         try:
             settings = get_settings()
-            private_key, public_key = generate_keypair()
+            private_key, public_key = await generate_keypair()
             psk = generate_preshared_key()
 
             async with async_session() as session:

wiregui/pages/devices.py

@@ -72,7 +72,7 @@ async def devices_page():
 
         try:
             settings = get_settings()
-            private_key, public_key = generate_keypair()
+            private_key, public_key = await generate_keypair()
             psk = generate_preshared_key()
 
             async with async_session() as session:

wiregui/utils/crypto.py

@@ -1,28 +1,37 @@
 """WireGuard key generation and encryption utilities."""
 
+import asyncio
 import base64
 import os
-import subprocess
 
 
-def generate_private_key() -> str:
+async def generate_private_key() -> str:
     """Generate a WireGuard private key using `wg genkey`."""
-    result = subprocess.run(["wg", "genkey"], capture_output=True, text=True, check=True)
-    return result.stdout.strip()
-
-
-def derive_public_key(private_key: str) -> str:
-    """Derive a WireGuard public key from a private key using `wg pubkey`."""
-    result = subprocess.run(
-        ["wg", "pubkey"], input=private_key, capture_output=True, text=True, check=True
+    proc = await asyncio.create_subprocess_exec(
+        "wg", "genkey", stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE,
     )
-    return result.stdout.strip()
+    stdout, _ = await proc.communicate()
+    if proc.returncode != 0:
+        raise RuntimeError("wg genkey failed")
+    return stdout.decode().strip()
 
 
-def generate_keypair() -> tuple[str, str]:
+async def derive_public_key(private_key: str) -> str:
+    """Derive a WireGuard public key from a private key using `wg pubkey`."""
+    proc = await asyncio.create_subprocess_exec(
+        "wg", "pubkey", stdin=asyncio.subprocess.PIPE,
+        stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE,
+    )
+    stdout, _ = await proc.communicate(input=private_key.encode())
+    if proc.returncode != 0:
+        raise RuntimeError("wg pubkey failed")
+    return stdout.decode().strip()
+
+
+async def generate_keypair() -> tuple[str, str]:
     """Generate a WireGuard keypair. Returns (private_key, public_key)."""
-    private_key = generate_private_key()
-    public_key = derive_public_key(private_key)
+    private_key = await generate_private_key()
+    public_key = await derive_public_key(private_key)
     return private_key, public_key