Python密码学Fernet AES加密换行符，缩进，回车

Question

我必须使用密钥对字符串进行加密并将加密的对象存储为字符串，因为它必须牢固，因此我决定使用提供aes加密的模块“密码学” https://pypi.org/project/cryptography/

如您所见，我制作了一系列函数来轻松使用Fernet加密，但是由于某些原因，它无法处理反斜杠，换行符，缩进和回车符，因此产生的解密与原始字符串不同，此处的测试字符串为"t\\n\\t"

from cryptography.fernet import Fernet
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
import base64

def encrypt_string(string_, password, f = None):
    if f is None:
        f = get_fernet_(password)
    try:
        return str(f.encrypt(string_.encode()))[2:- 1]
    except:
        return None

def decrypt_string(string_, password, f = None):
    if f is None:
        f = get_fernet_(password)
    try:
        return str(f.decrypt(string_.encode()))[2:- 1]
    except:
        return None

def get_fernet_(password):
    if password and isinstance(password,str):
        kdf = PBKDF2HMAC(algorithm = hashes.SHA256(),
                         length = 32,
                         salt = password.encode(),
                         iterations = 100000,
                         backend = default_backend())
        key = base64.urlsafe_b64encode(kdf.derive(password.encode()))
        f = Fernet(key)
        return f

def test_encryption(s = "text", password = "key"):
    my_f = get_fernet_(password)
    s2 = encrypt_string(s, password)
    s3 = decrypt_string(s2, password)
    s4 = encrypt_string(s, password, my_f)
    s5 = decrypt_string(s4, password, my_f)
    if s == s3 and s == s5:
        return True
    return False

print (test_encryption("text"))
True

print (test_encryption("t\n\t"))
False

如果有人可以提供针对此特定代码的解决方案或可以满足我需要的其他加密算法

Answer 1

问题是您试图使用str文字而不是bytes.decode()方法将bytes对象转换为string ：

from cryptography.fernet import Fernet

# Im just using a random key for simplicity
key = Fernet.generate_key()
f = Fernet(key)

mystr = 'hi\tthere'

enc = f.encrypt(mystr.encode()) # str.encode() creates a bytes object
dec = f.decrypt(enc)

str(dec)
# "b'hi\\tthere'"
# This is NOT the same, use decode

mystr==str(dec[2:-1]) # returns False
mystr==dec.decode() # returns True

dec.decode()
# 'hi\tthere'