derivepassphrase.git

Fix character set subtraction logic
Parent 407bbdd
Marco Ricci

Marco Ricci commited on 2024-06-08 19:06:56
Zeige 2 geänderte Dateien mit 22 Einfügungen und 5 Löschungen. 

Use a static method, and treat both the original character set and the
subtracted character set as sets (i.e. no repetitions allowed).
src/derivepassphrase/__init__.py
Zeige Datei @ 1e5d605
... ... 
@@ -305,27 +305,35 @@ class Vault:
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             ret = client.sign(key, cls._UUID)
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         return ret
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+    @staticmethod
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     def _subtract(
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-        self, charset: bytes | bytearray, allowed: bytes | bytearray,
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+        charset: bytes | bytearray, allowed: bytes | bytearray,
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     ) -> bytearray:
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         """Remove the characters in charset from allowed.
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         This preserves the relative order of characters in `allowed`.
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         Args:
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-            charset: Characters to remove.
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-            allowed: Character set to remove the other characters from.
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+            charset:
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+                Characters to remove.  Must not contain duplicate
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+                characters.
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+            allowed:
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+                Character set to remove the other characters from.  Must
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+                not contain duplicate characters.
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         Returns:
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-            The pruned character set.
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+            The pruned "allowed" character set.
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         Raises:
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-            ValueError: `charset` contained duplicate characters.
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+            ValueError:
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+                `allowed` or `charset` contained duplicate characters.
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         """
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         allowed = (allowed if isinstance(allowed, bytearray)
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                    else bytearray(allowed))
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         assert_type(allowed, bytearray)
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+        if len(frozenset(allowed)) != len(allowed):
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+            raise ValueError('duplicate characters in set')
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         if len(frozenset(charset)) != len(charset):
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             raise ValueError('duplicate characters in set')
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         for c in charset:
tests/test_passphrase_generating.py
Zeige Datei @ 1e5d605
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@@ -113,3 +113,12 @@ def test_220_very_limited_character_set():
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     generated = Vault(phrase=b'', length=24, lower=0, upper=0,
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                       space=0, symbol=0).generate('testing')
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     assert b'763252593304946694588866' == generated
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+
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+def test_300_character_set_subtraction():
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+    assert Vault._subtract(b'be', b'abcdef') == bytearray(b'acdf')
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+
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+def test_301_character_set_subtraction_duplicate():
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+    with pytest.raises(ValueError, match='duplicate characters'):
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+        Vault._subtract(b'abcdef', b'aabbccddeeff')
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+    with pytest.raises(ValueError, match='duplicate characters'):
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+        Vault._subtract(b'aabbccddeeff', b'abcdef')
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