【編程】Python3 使用自定義編碼字符表解密Base64數據

前言

Python提供了“base64”模塊用於編碼、解碼Base64數據。
但是並不是所有的Base64數據都會使用默認的字符表進行編碼，所以這里對Python下實現自定義編碼字符表解密Base64數據做一個簡要記錄。（關於Base64內部實現等相關內容可以參考這篇文章）

Python2.7

# -*- coding: utf-8
import base64
import string

STANDARD_ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
CUSTOM_ALPHABET = 'JXaYOjSNTet1dDrHsVlc0m5EknG7Ko6qibhFBuyzQUwxWCp4ZLf23gAvMR8PI9+/'
ENCODE_TRANS = string.maketrans(STANDARD_ALPHABET, CUSTOM_ALPHABET)
DECODE_TRANS = string.maketrans(CUSTOM_ALPHABET, STANDARD_ALPHABET)

def encode(input):
    return base64.b64encode(input).translate(ENCODE_TRANS)

def decode(input):
    return base64.b64decode(input.translate(DECODE_TRANS))

enstr = encode("123")
print enstr #dcT2

destr = decode(enstr)
print destr #123

Python3.8

# -*- coding: utf-8
import base64

STANDARD_ALPHABET = b'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
CUSTOM_ALPHABET = b'JXaYOjSNTet1dDrHsVlc0m5EknG7Ko6qibhFBuyzQUwxWCp4ZLf23gAvMR8PI9+/'
ENCODE_TRANS = bytes.maketrans(STANDARD_ALPHABET, CUSTOM_ALPHABET)
DECODE_TRANS = bytes.maketrans(CUSTOM_ALPHABET, STANDARD_ALPHABET)

def encode(input):
  return base64.b64encode(input).translate(ENCODE_TRANS)

def decode(input):
  return base64.b64decode(input.translate(DECODE_TRANS))

enstr = encode("123".encode())
print(enstr.decode()) #dcT2

destr = decode(enstr)
print(destr.decode()) #123

參考鏈接：

https://bbs.khcloud.net/?thread-285.htm