使用bouncycastle在C#中使用cryptodome解密在python中加密的RSA数据会给出不正确的错误块

Question

我正在使用以下函数在PHP中加密RSA数据：

function RSAEncrypt($text){
$priv_key=file_get_contents("privateKey.key");
//$passphrase is required if your key is encoded (suggested)
$priv_key_res = openssl_get_privatekey($priv_key);

if(!openssl_private_encrypt($text,$crypttext,$priv_key_res)){
echo "Error: " . openssl_error_string ();
}
return $crypttext;
}

我使用以下函数在 C# 中解码它：

public static string RSADecrypt(string b64cipher, string pemcert) {
byte[] bytesCypherText = Convert.FromBase64String(b64cipher);
Org.BouncyCastle.X509.X509Certificate cert = (Org.BouncyCastle.X509.X509Certificate)new Org.BouncyCastle.OpenSsl.PemReader(new StringReader(pemcert)).ReadObject();
var decryptEngine = new Pkcs1Encoding(new RsaEngine());
//var decryptEngine = new OaepEncoding(new RsaEngine());
decryptEngine.Init(false, cert.GetPublicKey());
string decrypted = Encoding.UTF8.GetString(decryptEngine.ProcessBlock(bytesCypherText, 0, bytesCypherText.Length));
return decrypted;
}

我想用python替换PHP函数，并尝试了以下方法：

from Cryptodome.PublicKey import RSA
from Cryptodome.Cipher import PKCS1_OAEP, AES, PKCS1_v1_5
import base64
from Cryptodome import Random
from Cryptodome.Random import get_random_bytes
import hashlib
def encrypt_private_key(a_message):
with open("privateKey.key", 'r') as f:
private_key = RSA.importKey(f.read())
#encryptor = PKCS1_OAEP.new(private_key)
encryptor= PKCS1_v1_5.new(private_key)
encrypted_msg = encryptor.encrypt(a_message.encode())
encoded_encrypted_msg = base64.b64encode(encrypted_msg)
return encoded_encrypted_msg

但是，在解码时出现以下错误：

InvalidCipherTextException: block incorrect
at byte[] Org.BouncyCastle.Crypto.Encodings.Pkcs1Encoding.DecodeBlock
(byte[] input, int inOff, int inLen) at string RSADecrypt (string
b64cipher, string pemcert)

如果我尝试使用PKCS1_OAEP(在python和c#中，请参阅注释代码(，则会出现数据错误的异常。

不知道我错过了什么

Answer 1

经过一些研究，似乎python lirary不允许进行私钥加密，因为它不是标准操作，但是就我而言，我仍然想这样做，并在此处使用了代码： https://www.php2python.com/wiki/function.openssl-private-encrypt/

from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.serialization import load_pem_private_key
def openssl_private_encrypt(data):
"""Encrypt data with RSA private key.
This is a rewrite of the function from PHP, using cryptography
FFI bindings to the OpenSSL library. Private key encryption is
non-standard operation and Python packages either don't offer
it at all, or it's incompatible with the PHP version.
The backend argument MUST be the OpenSSL cryptography backend.
"""
# usage
key = load_pem_private_key(open("key.pem").read().encode(
'ascii'), None, backend=default_backend())
backend = default_backend()
length = backend._lib.EVP_PKEY_size(key._evp_pkey)
buffer = backend._ffi.new('unsigned char[]', length)
result = backend._lib.RSA_private_encrypt(
len(data), data, buffer,
backend._lib.EVP_PKEY_get1_RSA(key._evp_pkey),
backend._lib.RSA_PKCS1_PADDING)
backend.openssl_assert(result == length)
res = backend._ffi.buffer(buffer)[:]
print(res)
return base64.b64encode(backend._ffi.buffer(buffer)[:]).decode()