15. 加密服务

15.1. hashlib

该模块实现了许多不同安全散列和消息摘要算法的通用接口。

# 导入
In [1]: import hashlib

# 支持的算法
In [6]: hashlib.algorithms_available
Out[6]:
{'DSA',
'DSA-SHA',
'MD4',
'MD5',
'RIPEMD160',
'SHA',
'SHA1',
'SHA224',
'SHA256',
'SHA384',
'SHA512',
'blake2b',
'blake2s',
'dsaEncryption',
'dsaWithSHA',
'ecdsa-with-SHA1',
'md4',
'md5',
'ripemd160',
'sha',
'sha1',
'sha224',
'sha256',
'sha384',
'sha3_224',
'sha3_256',
'sha3_384',
'sha3_512',
'sha512',
'shake_128',
'shake_256',
'whirlpool'}

# 获取数字签名
In [5]:  hashlib.sha224(b"Nobody inspects the spammish repetition").hexdigest()
Out[5]: 'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'

# 使用string构造，并签名数据。
In [12]: h = hashlib.new("sha224")

#  m.update(a); m.update(b) 相当于 m.update(a+b).
In [13]: h.update(b"Nobody inspects the spammish repetition")

In [15]: h.hexdigest()
Out[15]: 'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'

# blake2b数字签名
In [18]: from hashlib import blake2b

In [19]: items = [b'hello',b' ',b'world']

In [20]: h=blake2b()

In [21]: for item in items:
    ...:     h.update(item)
    ...:

In [22]: h.hexdigest()
Out[22]: '021ced8799296ceca557832ab941a50b4a11f83478cf141f51f933f653ab9fbcc05a037cddbed06e309bf334942c4e58cdf1a46e237911ccd7fcf9787cbc7fd0'

15.2. hmac

实现了hmac算法。

提供了new,update,digest,hexdigest方法，使用起来和hashlib基本一样。

15.3. secrets

用于生成适合于管理密码，账户认证，安全令牌和相关机密等数据的密码强的随机数。

# 生成令牌数
In [23]: import secrets

In [24]: secrets.token_hex(8)
Out[24]: 'fc7a82326d332952'

# 生成8位的字母数字密码

In [27]: import random

In [28]: import string
    ...: alphabet = string.ascii_letters + string.digits
    ...: password = ''.join(random.choice(alphabet) for i in range(8))
    ...:

In [29]: password
Out[29]: 'U4M4K62h'

# 生成指定复杂度的密码
import string
alphabet = string.ascii_letters + string.digits
while True:
    password = ''.join(choice(alphabet) for i in range(10))
    if (any(c.islower() for c in password)
            and any(c.isupper() for c in password)
            and sum(c.isdigit() for c in password) >= 3):
        break