python實現AES加密、解密

AES加密方式有五種：ECB, CBC, CTR, CFB, OFB

從安全性角度推薦CBC加密方法，本文介紹了CBC,ECB兩種加密方法的python實現

python 在 Windows下使用AES時要安裝的是pycryptodome 模塊   pip install pycryptodome 

python 在 Linux下使用AES時要安裝的是pycrypto模塊   pip install pycrypto 

CBC加密需要一個十六位的key(密鑰)和一個十六位iv(偏移量)

ECB加密不需要iv

AES CBC 加密的python實現

from Crypto.Cipher import AES
from binascii import b2a_hex, a2b_hex


# 如果text不足16位的倍數就用空格補足為16位
def add_to_16(text):
    if len(text.encode('utf-8')) % 16:
        add = 16 - (len(text.encode('utf-8')) % 16)
    else:
        add = 0
    text = text + ('\0' * add)
    return text.encode('utf-8')


# 加密函數
def encrypt(text):
    key = '9999999999999999'.encode('utf-8')
    mode = AES.MODE_CBC
    iv = b'qqqqqqqqqqqqqqqq'
    text = add_to_16(text)
    cryptos = AES.new(key, mode, iv)
    cipher_text = cryptos.encrypt(text)
    # 因為AES加密后的字符串不一定是ascii字符集的，輸出保存可能存在問題，所以這里轉為16進制字符串
    return b2a_hex(cipher_text)


# 解密后，去掉補足的空格用strip() 去掉
def decrypt(text):
    key = '9999999999999999'.encode('utf-8')
    iv = b'qqqqqqqqqqqqqqqq'
    mode = AES.MODE_CBC
    cryptos = AES.new(key, mode, iv)
    plain_text = cryptos.decrypt(a2b_hex(text))
    return bytes.decode(plain_text).rstrip('\0')


if __name__ == '__main__':
    e = encrypt("hello world")  # 加密
    d = decrypt(e)  # 解密
    print("加密:", e)
    print("解密:", d)

AES ECB加密的python實現

"""
ECB沒有偏移量
"""
from Crypto.Cipher import AES
from binascii import b2a_hex, a2b_hex


def add_to_16(text):
    if len(text.encode('utf-8')) % 16:
        add = 16 - (len(text.encode('utf-8')) % 16)
    else:
        add = 0
    text = text + ('\0' * add)
    return text.encode('utf-8')


# 加密函數
def encrypt(text):
    key = '9999999999999999'.encode('utf-8')
    mode = AES.MODE_ECB
    text = add_to_16(text)
    cryptos = AES.new(key, mode)

    cipher_text = cryptos.encrypt(text)
    return b2a_hex(cipher_text)


# 解密后，去掉補足的空格用strip() 去掉
def decrypt(text):
    key = '9999999999999999'.encode('utf-8')
    mode = AES.MODE_ECB
    cryptor = AES.new(key, mode)
    plain_text = cryptor.decrypt(a2b_hex(text))
    return bytes.decode(plain_text).rstrip('\0')


if __name__ == '__main__':
    e = encrypt("hello world")  # 加密
    d = decrypt(e)  # 解密
    print("加密:", e)
    print("解密:", d)