用Crypto++加密，用Python.CRYPTO解密

Question

我正在做一个项目，它使用Crypto++来加密一些数据。

下面是我的Crypto++代码：

string plain = "Text123", encoded, cipher;
string pkey = "...";

StringSource ss1(pkey, true);
RSA::PublicKey publicKey;
PEM_Load(ss, publicKey);
RSAES_OAEP_SHA_Encryptor e(publicKey);

StringSource ss2(plain, true,
    new PK_EncryptorFilter(prng, e,
        new StringSink(cipher)
    ) 
); 

StringSource ss3(cipher, true,
    new Base64Encoder(
        new StringSink(encoded)
    )
);
cout << encoded;

我正试着用Python解密加密信息。以下是我的Python代码：

from Crypto.PublicKey import RSA
from base64 import b64decode  

cipher_text = "[THE OUTPUT OF C++]"
rsakey = RSA.importKey(open("private.txt", "r").read())
raw_cipher_data = b64decode(cipher_text)
decrypted = rsakey.decrypt(raw_cipher_data)

但是我得到了一些无法阅读的字符。

为什么我会得到不可读的字符？有人能帮我这个忙吗？

提前谢谢。

Answer 1

以下是在C++中加密明文和在Python中解密明文的完整工作示例：

先决条件

您已生成 key pair (reference).

• 您有最新版本的crypto++ (我使用的是8.2.0)，并且您已经应用了PEM补丁(reference).

• 你有一个最新版本的pycryptodome (我用的是3.9.8)。pycryptodome是不再维护的pycrypto包(reference).

的临时替代品

加密

你的C++做了正确的事情。为了完整起见，我使用必要的头包含和公钥的反序列化扩展了您的代码：

#include <cryptopp/base64.h>
#include <cryptopp/files.h>
#include <cryptopp/filters.h>
#include <cryptopp/osrng.h>
#include <cryptopp/pem.h>
#include <cryptopp/rng.h>
#include <cryptopp/rsa.h>

#include <iostream>

int main(int argc, char **argv) {

  CryptoPP::AutoSeededRandomPool prng{};

  std::string plain{"Text123"};

  /**
   * Read public key in PEM format.
   */
  CryptoPP::FileSource fs{"public.pem", /*pumpAll=*/true};
  CryptoPP::RSA::PublicKey publicKey{};
  PEM_Load(fs, publicKey);

  std::string encrypted{};

  /**
   * Pump plain text through RSA encryption scheme with OAEP/SHA1 padding.
   *
   * In general, manual memory allocations should be avoided. However,
   * the CryptoPP API expects us to allocate memory for each transformer and
   * then pass the pointer to the next transformer, which then takes ownership
   * of the pointer and will free it. This design obviously predates
   * modern C++ smart pointers, which should be preferred when possible.
   */
  CryptoPP::RSAES_OAEP_SHA_Encryptor cipher{publicKey};
  auto *encoder{
      new CryptoPP::Base64Encoder{new CryptoPP::StringSink{encrypted}}};
  auto *encryptor{new CryptoPP::PK_EncryptorFilter{prng, cipher, encoder}};
  CryptoPP::StringSource ss{plain, /*pumpAll=*/true, encryptor};

  std::cout << encrypted;

  return 0;
}

解密

在Python代码中，您没有指定填充方案。由于您的C++代码使用OAEP/SHA1填充，因此您还必须在Python代码中指定此填充方案：

from base64 import b64decode

from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_OAEP
from Crypto.Hash import SHA1

rsa_key = None
encrypted = None

with open("key.pem", "r") as f:
  rsa_key = RSA.importKey(f.read())

with open("encrypted", "r") as f:
  encrypted = b64decode(f.read())

cipher = PKCS1_OAEP.new(rsa_key, hashAlgo=SHA1)
decrypted = cipher.decrypt(encrypted)

print(decrypted)