diff options
Diffstat (limited to 'lib/python3.11/site-packages/itsdangerous/encoding.py')
| -rw-r--r-- | lib/python3.11/site-packages/itsdangerous/encoding.py | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/lib/python3.11/site-packages/itsdangerous/encoding.py b/lib/python3.11/site-packages/itsdangerous/encoding.py new file mode 100644 index 0000000..edb04d1 --- /dev/null +++ b/lib/python3.11/site-packages/itsdangerous/encoding.py @@ -0,0 +1,54 @@ +import base64 +import string +import struct +import typing as _t + +from .exc import BadData + +_t_str_bytes = _t.Union[str, bytes] + + +def want_bytes( + s: _t_str_bytes, encoding: str = "utf-8", errors: str = "strict" +) -> bytes: + if isinstance(s, str): + s = s.encode(encoding, errors) + + return s + + +def base64_encode(string: _t_str_bytes) -> bytes: + """Base64 encode a string of bytes or text. The resulting bytes are + safe to use in URLs. + """ + string = want_bytes(string) + return base64.urlsafe_b64encode(string).rstrip(b"=") + + +def base64_decode(string: _t_str_bytes) -> bytes: + """Base64 decode a URL-safe string of bytes or text. The result is + bytes. + """ + string = want_bytes(string, encoding="ascii", errors="ignore") + string += b"=" * (-len(string) % 4) + + try: + return base64.urlsafe_b64decode(string) + except (TypeError, ValueError) as e: + raise BadData("Invalid base64-encoded data") from e + + +# The alphabet used by base64.urlsafe_* +_base64_alphabet = f"{string.ascii_letters}{string.digits}-_=".encode("ascii") + +_int64_struct = struct.Struct(">Q") +_int_to_bytes = _int64_struct.pack +_bytes_to_int = _t.cast("_t.Callable[[bytes], _t.Tuple[int]]", _int64_struct.unpack) + + +def int_to_bytes(num: int) -> bytes: + return _int_to_bytes(num).lstrip(b"\x00") + + +def bytes_to_int(bytestr: bytes) -> int: + return _bytes_to_int(bytestr.rjust(8, b"\x00"))[0] |
