Python 密码加盐和加胡椒

Question

我目前正在创建一个 class 来处理与密码相关的功能（散列和验证）。我在这方面的知识很基础。

经过一些研究，我很明显应该使用一个已经很好的哈希库。我选择了bycrypt。还建议我应该为每个密码使用唯一的盐，以及不存储在数据库中的全局胡椒。我的代码运行没问题，可以正常工作。

我的问题是，我是否正确地添加了密码？现在我首先用 sha256 加密密码，然后我运行用独特的盐对其进行加密。我读过 sha256 不是为密码散列而设计的，因此在我们的情况下它不安全，但我应该使用什么来代替它？作为不了解密码散列的人这样安全吗，还是我应该更改一些内容？

编辑： 如果我的代码太长，这是我质疑的浓缩部分：

import bycrypt
import hashlib
import hmac

password = "vEryC0mPl3X!!!"

PEPPER = "randompepperstring"
salt = bycrypt.gensalt()

peppered_password = hmac.new(PEPPER.encode("utf-8"), password.encode("utf-8"), hashlib.sha256).hexdigest()
salted_peppered_password = bycrypt.hashpw(peppered_password.encode("utf-8"), salt)
heashed_password = salted_peppered_password.decode("utf-8")

完整代码：

from bcrypt import hashpw, checkpw, gensalt
from hashlib import sha256
from hmac import new

class EmailNotFoundError(Exception):
    pass

class PasswordError(Exception):
    pass

class PasswordLengthError(PasswordError):
    pass

class PasswordNotComplexError(PasswordError):
    pass

class PasswordManager:

    PEPPER = "randompepperstring"

    def _GenerateSalt() -> bytes:
        return gensalt()

    def _PepperPassword(password: str) -> str:
        return new(PasswordManager.PEPPER.encode("utf-8"), password.encode("utf-8"), sha256).hexdigest()

    def _SaltPassword(password: str, salt: bytes) -> bytes:
        password_bytes = password.encode('utf-8')
        return hashpw(password_bytes, salt)

    def _GetPasswordOfEmail(email: str) -> str:
        # hashed_pw is for testing purposes currently
        # result should come from and sql select, eg: SELECT CASE WHEN COUNT(1) > 0 THEN HashedPassword ELSE NULL END AS [HashedPassword] FROM Users WHERE Email LIKE email
        # result will select SQL NULL if no e-mail is found, which becomes a None in Python
        result = hashed_pw
        if result == None:
            raise EmailNotFoundError("The provided e-mail address does not exist in our database.")
        return result.encode("utf-8")

    def _ValidPasswordFormat(password: str) -> None:
        if 8 > len(password) >= 72:
            raise PasswordLengthError(f"The password should be between 8 and 72 characters long. The provided password '{password}' is {len(password)} characters long.")
        if not any(map(str.isdigit, password)):
            raise PasswordNotComplexError("The password contains no numbers. The password should contain at least 1 number, symbol, uppercase letter and lowercase letter.")
        if not any(map(str.islower, password)):
            raise PasswordNotComplexError("The password contains no lowercase letters. The password should contain at least 1 number, symbol, uppercase letter and lowercase letter.")
        if not any(map(str.isupper, password)):
            raise PasswordNotComplexError("The password contains no uppercase letters. The password should contain at least 1 number, symbol, uppercase letter and lowercase letter.")
        if not any(char in '!"#$%&\'()*+,-./:;<=>?@[\]^_`{|}~' for char in password):
            raise PasswordNotComplexError("The password contains no symbols (for example ! or * or = ...). The password should contain at least 1 number, symbol, uppercase letter and lowercase letter.")

    def HashPassword(password: str) -> str:

        PasswordManager._ValidPasswordFormat(password)
        salt =  PasswordManager._GenerateSalt()
        peppered_password = PasswordManager._PepperPassword(password)
        salted_peppered_password = PasswordManager._SaltPassword(peppered_password, salt)
        return salted_peppered_password.decode("utf-8")

    def VerifyLogin(email: str, input_password: str) -> bool:

        stored_password = PasswordManager._GetPasswordOfEmail(email)
        return checkpw(PasswordManager._PepperPassword(input_password).encode('utf-8'), stored_password)

# TESTING
hashed_pw = PasswordManager.HashPassword("vEryC0mPl3X!!!")
print(PasswordManager.VerifyLogin("john@gmail.com", "vEryC0mPl3X!!!"))
print(PasswordManager.VerifyLogin("john@gmail.com", "not"))
print(PasswordManager.VerifyLogin("john@gmail.com", "good"))
print(PasswordManager.VerifyLogin("john@gmail.com", "at all"))

Answer 1

据我所知，你做的是对的。

I've read that sha256 is not made for password hashing so it is not secure

这意味着，您不应使用 SHA256 散列密码并将其存储在数据库中。

不代表不能用来做辣椒

我在这里可以推荐的一点是不要使用普通的 SHA-256，而是使用胡椒的组合。也许像该密码的 SHA-256 + MD-5 或 SHA-1 的一部分。

如果您使用更高的哈希算法，则需要更多的计算。假设您可能会添加更多功能，例如不应使用旧密码或类似于旧密码，更多的计算会被浪费。

Python 密码加盐和加胡椒

Python Password Salting and Peppering

python

security

passwords

hash

salt