Python中的RSA加密和解密

I need help using RSA encryption and decryption in Python.

我需要在Python中使用RSA加密和解密的帮助。

I am creating a private/public key pair, encrypting a message with keys and writing message to a file. Then I am reading ciphertext from file and decrypting text using key.

我正在创建一个私钥/公钥对，用密钥加密消息并将消息写入文件。然后我正在从文件中读取密文并使用密钥解密文本。

I am having trouble with the decryption portion. As you can see in my code below, when I put in decrypted = key.decrypt(message) that the program works, yet the decrypted message is encrypted again. It seems like it is not reading the ciphertext from the file.

我在解密部分遇到问题。正如您在下面的代码中所看到的，当我输入decrypted = key.decrypt（message）程序正常工作时，解密的消息再次被加密。好像它不是从文件中读取密文。

Can anyone help me write this code so decryption reads ciphertext from file and then uses key to decrypt ciphertext?

任何人都可以帮我写这段代码，所以解密从文件中读取密文，然后使用密钥解密密文？

import Crypto
from Crypto.PublicKey import RSA
from Crypto import Random

random_generator = Random.new().read
key = RSA.generate(1024, random_generator) #generate public and private keys

publickey = key.publickey # pub key export for exchange

encrypted = publickey.encrypt('encrypt this message', 32)
#message to encrypt is in the above line 'encrypt this message'

print 'encrypted message:', encrypted #ciphertext

f = open ('encryption.txt', 'w'w)
f.write(str(encrypted)) #write ciphertext to file
f.close()

#decrypted code below

f = open ('encryption.txt', 'r')
message = f.read()

decrypted = key.decrypt(message)

print 'decrypted', decrypted

f = open ('encryption.txt', 'w')
f.write(str(message))
f.write(str(decrypted))
f.close()

3 个解决方案

#1

In order to make it work you need to convert key from str to tuple before decryption(ast.literal_eval function). Here is fixed code:

为了使其工作，您需要在解密之前将密钥从str转换为元组（ast.literal_eval函数）。这是固定代码：

import Crypto
from Crypto.PublicKey import RSA
from Crypto import Random
import ast

random_generator = Random.new().read
key = RSA.generate(1024, random_generator) #generate pub and priv key

publickey = key.publickey() # pub key export for exchange

encrypted = publickey.encrypt('encrypt this message', 32)
#message to encrypt is in the above line 'encrypt this message'

print 'encrypted message:', encrypted #ciphertext
f = open ('encryption.txt', 'w')
f.write(str(encrypted)) #write ciphertext to file
f.close()

#decrypted code below

f = open('encryption.txt', 'r')
message = f.read()


decrypted = key.decrypt(ast.literal_eval(str(encrypted)))

print 'decrypted', decrypted

f = open ('encryption.txt', 'w')
f.write(str(message))
f.write(str(decrypted))
f.close()

#2

# coding: utf-8
from __future__ import unicode_literals
import base64
import os

import six
from Crypto import Random
from Crypto.PublicKey import RSA


class PublicKeyFileExists(Exception): pass


class RSAEncryption(object):
    PRIVATE_KEY_FILE_PATH = None
    PUBLIC_KEY_FILE_PATH = None

    def encrypt(self, message):
        public_key = self._get_public_key()
        public_key_object = RSA.importKey(public_key)
        random_phrase = 'M'
        encrypted_message = public_key_object.encrypt(self._to_format_for_encrypt(message), random_phrase)[0]
        # use base64 for save encrypted_message in database without problems with encoding
        return base64.b64encode(encrypted_message)

    def decrypt(self, encoded_encrypted_message):
        encrypted_message = base64.b64decode(encoded_encrypted_message)
        private_key = self._get_private_key()
        private_key_object = RSA.importKey(private_key)
        decrypted_message = private_key_object.decrypt(encrypted_message)
        return six.text_type(decrypted_message, encoding='utf8')

    def generate_keys(self):
        """Be careful rewrite your keys"""
        random_generator = Random.new().read
        key = RSA.generate(1024, random_generator)
        private, public = key.exportKey(), key.publickey().exportKey()

        if os.path.isfile(self.PUBLIC_KEY_FILE_PATH):
            raise PublicKeyFileExists('Файл с публичным ключом существует. Удалите ключ')
        self.create_directories()

        with open(self.PRIVATE_KEY_FILE_PATH, 'w') as private_file:
            private_file.write(private)
        with open(self.PUBLIC_KEY_FILE_PATH, 'w') as public_file:
            public_file.write(public)
        return private, public

    def create_directories(self, for_private_key=True):
        public_key_path = self.PUBLIC_KEY_FILE_PATH.rsplit('/', 1)
        if not os.path.exists(public_key_path):
            os.makedirs(public_key_path)
        if for_private_key:
            private_key_path = self.PRIVATE_KEY_FILE_PATH.rsplit('/', 1)
            if not os.path.exists(private_key_path):
                os.makedirs(private_key_path)

    def _get_public_key(self):
        """run generate_keys() before get keys """
        with open(self.PUBLIC_KEY_FILE_PATH, 'r') as _file:
            return _file.read()

    def _get_private_key(self):
        """run generate_keys() before get keys """
        with open(self.PRIVATE_KEY_FILE_PATH, 'r') as _file:
            return _file.read()

    def _to_format_for_encrypt(value):
        if isinstance(value, int):
            return six.binary_type(value)
        for str_type in six.string_types:
            if isinstance(value, str_type):
                return value.encode('utf8')
        if isinstance(value, six.binary_type):
            return value

And use

并使用

KEYS_DIRECTORY = settings.SURVEY_DIR_WITH_ENCRYPTED_KEYS

class TestingEncryption(RSAEncryption):
    PRIVATE_KEY_FILE_PATH = KEYS_DIRECTORY + 'private.key'
    PUBLIC_KEY_FILE_PATH = KEYS_DIRECTORY + 'public.key'


# django/flask
from django.core.files import File

class ProductionEncryption(RSAEncryption):
    PUBLIC_KEY_FILE_PATH = settings.SURVEY_DIR_WITH_ENCRYPTED_KEYS + 'public.key'

    def _get_private_key(self):
        """run generate_keys() before get keys """
        from corportal.utils import global_elements
        private_key = global_elements.request.FILES.get('private_key')
        if private_key:
            private_key_file = File(private_key)
            return private_key_file.read()

message = 'Hello мой friend'
encrypted_mes = ProductionEncryption().encrypt(message)
decrypted_mes = ProductionEncryption().decrypt(message)

#3

from Crypto.Cipher import DES

des = DES.new('01234567', DES.MODE_ECB)
text = "abcdefgh8"
leno = len(text)
if leno % 8 != 0:
    for i in range(0, 8 -leno%8):
        text += " "

cipher_text = des.encrypt(text)

des.decrypt(cipher_text)

In above code basically, you can encrypte your text with a password like "01234567" and decrypte it again with that password. It is simple. The only caution is, your text length should be power of 8, so there is a little for loop that adds enough space to make your text's length divisible by 8. Thats it.

基本上，在上面的代码中，您可以使用密码“01234567”加密文本，并使用该密码再次解密。很简单。唯一要注意的是，你的文本长度应该是8的幂，所以有一个小的for循环，增加了足够的空间，使你的文本的长度可以被8整除。这就是它。