bpo-32502: Discard 64-bit (and other invalid) hardware addresses (#5254)

1 files changed, 10 insertions, 6 deletions

diff --git a/Lib/uuid.py b/Lib/uuid.py
index b7433cb..ef7b3b5 100644
--- a/Lib/uuid.py
+++ b/Lib/uuid.py
@@ -656,7 +656,12 @@ def _random_getnode():
 
 _node = None
 
-def getnode():
+_NODE_GETTERS_WIN32 = [_windll_getnode, _netbios_getnode, _ipconfig_getnode]
+
+_NODE_GETTERS_UNIX = [_unix_getnode, _ifconfig_getnode, _ip_getnode,
+                      _arp_getnode, _lanscan_getnode, _netstat_getnode]
+
+def getnode(*, getters=None):
     """Get the hardware address as a 48-bit positive integer.
 
     The first time this runs, it may launch a separate program, which could
@@ -669,19 +674,18 @@ def getnode():
         return _node
 
     if sys.platform == 'win32':
-        getters = [_windll_getnode, _netbios_getnode, _ipconfig_getnode]
+        getters = _NODE_GETTERS_WIN32
     else:
-        getters = [_unix_getnode, _ifconfig_getnode, _ip_getnode,
-                   _arp_getnode, _lanscan_getnode, _netstat_getnode]
+        getters = _NODE_GETTERS_UNIX
 
     for getter in getters + [_random_getnode]:
         try:
             _node = getter()
         except:
             continue
-        if _node is not None:
+        if (_node is not None) and (0 <= _node < (1 << 48)):
             return _node
-    assert False, '_random_getnode() returned None'
+    assert False, '_random_getnode() returned invalid value: {}'.format(_node)
 
 
 _last_timestamp = None