Handle oversized base62 values

ksuid/ksuid.py

@@ -48,7 +48,13 @@ class Ksuid:
     @classmethod
     def from_base62(cls: type[SelfT], data: str) -> SelfT:
         """initializes Ksuid from base62 encoding"""
-        return cls.from_bytes(int.to_bytes(int(base62.decode(data)), cls.BYTES_LENGTH, "big"))
+        decoded = int(base62.decode(data))
+        try:
+            value = int.to_bytes(decoded, cls.BYTES_LENGTH, "big")
+        except OverflowError as exc:
+            byte_length = (decoded.bit_length() + 7) // 8
+            raise ByteArrayLengthException(f"Incorrect value length {byte_length}") from exc
+        return cls.from_bytes(value)
 
     @classmethod
     def from_bytes(cls: type[SelfT], value: bytes) -> SelfT:

tests/test_ksuid.py

@@ -72,6 +72,12 @@ def test_to_from_base62():
     assert ksuid == ksuid_from_base62
 
 
+@pytest.mark.parametrize("ksuid_cls", [Ksuid, KsuidMs])
+def test_from_base62_rejects_oversized_value(ksuid_cls):
+    with pytest.raises(ByteArrayLengthException):
+        ksuid_cls.from_base62("z" * ksuid_cls.BASE62_LENGTH)
+
+
 def test_eq_with_non_ksuid_does_not_raise():
     ksuid = Ksuid.from_bytes(bytes(Ksuid.BYTES_LENGTH))