Share logic for checking key line validity

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/admin_views.py

@@ -45,6 +45,21 @@ KNOWN_HOSTS_FILE = os.path.expanduser('~/.ssh/known_hosts')
 RSA_KEY_FILE = os.path.expanduser('~/.ssh/id_rsa.pub')
 
 
+def is_key_line(key):
+    """
+    Checks whether this line looks like a valid known_hosts line.
+    """
+    if not key:
+        return False
+    if key[0] == '#':
+        return False
+    return (
+        ' ssh-rsa ' in key
+        or ' ecdsa-sha2-nistp256 ' in key
+        or ' ssh-ed25519 ' in key
+    )
+
+
 @staff_member_required
 def report(request):
     """
@@ -214,7 +229,8 @@ def get_host_keys():
         result = []
         with open(KNOWN_HOSTS_FILE, 'r') as handle:
             for line in handle:
-                if ' ssh-rsa ' in line or ' ecdsa-sha2-nistp256 ' in line:
+                line = line.strip()
+                if is_key_line(line):
                     result.append(parse_hosts_line(line))
     except IOError:
         return []
@@ -293,9 +309,8 @@ def add_host_key(request):
             )
             keys = []
             for key in output.splitlines():
-                if (' ssh-rsa ' not in key
-                        and ' ecdsa-sha2-nistp256 ' not in key
-                        and ' ssh-ed25519 ' not in key):
+                key = key.strip()
+                if not is_key_line(key):
                     continue
                 keys.append(key)
                 host, keytype, fingerprint = parse_hosts_line(key)