1  import base64
 2  import os
 3  import string
 4  
 5  charset = string.ascii_uppercase + string.ascii_lowercase + string.digits + "+/"
 6  
 7  
 8  def base64encode(data: bytes) -> str:
 9      bits = "".join([bin(c)[2:].rjust(8, '0') for c in data]) + "0" * ((3 - len(data)) % 3 * 2)
10      chunks = [bits[i * 6:(i + 1) * 6] for i in range(len(bits) // 6)]
11      return "".join([charset[int(c, 2)] for c in chunks]) + "=" * ((3 - len(data)) % 3)
12  
13  
14  def base64decode(data: str) -> bytes:
15      padding = data.count("=")
16      data = data.strip("=")
17      bits = "".join([bin(charset.index(c))[2:].rjust(6, '0') for c in data])
18      if padding:
19          bits = bits[:-padding * 2]
20      return bytes([int(bits[i * 8:(i + 1) * 8], 2) for i in range(len(bits) // 8)])
21  
22  
23  def test(inp: bytes, enc: callable, enc2: callable, dec: callable):
24      print("Input:", inp)
25      my = enc(inp)
26      print("My Output:", my)
27      correct = enc2(inp).decode()
28      print("Correct Output:", correct)
29      if my == correct:
30          dec = dec(my)
31          print("Decoded:", dec)
32          print(dec == inp)
33      else:
34          print(False)
35  
36  
37  test(os.urandom(385), base64encode, base64.b64encode, base64decode)