forked from s434650/CatOrNot
50 lines
1.2 KiB
Python
50 lines
1.2 KiB
Python
import base64
|
|
import string
|
|
import struct
|
|
|
|
from ._compat import text_type
|
|
from .exc import BadData
|
|
|
|
|
|
def want_bytes(s, encoding="utf-8", errors="strict"):
|
|
if isinstance(s, text_type):
|
|
s = s.encode(encoding, errors)
|
|
return s
|
|
|
|
|
|
def base64_encode(string):
|
|
"""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):
|
|
"""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):
|
|
raise BadData("Invalid base64-encoded data")
|
|
|
|
|
|
# The alphabet used by base64.urlsafe_*
|
|
_base64_alphabet = (string.ascii_letters + string.digits + "-_=").encode("ascii")
|
|
|
|
_int64_struct = struct.Struct(">Q")
|
|
_int_to_bytes = _int64_struct.pack
|
|
_bytes_to_int = _int64_struct.unpack
|
|
|
|
|
|
def int_to_bytes(num):
|
|
return _int_to_bytes(num).lstrip(b"\x00")
|
|
|
|
|
|
def bytes_to_int(bytestr):
|
|
return _bytes_to_int(bytestr.rjust(8, b"\x00"))[0]
|