RSA加密和解密使用2个文件

Question

所以我创建了 2 个文件，一个用于加密，另一个用于解密。我能够加密文本，但在解密时出现错误（见问题底部）。我能够导出 Private_key.pem、public_key.pem 甚至是 secret.txt 文件。我可以在我的 decrypt.py 脚本中读取 private_key.pem，但它会出错。我相信脚本认为它使用的 private_key 不正确。我知道这是错误的，因为我生成了公钥和私钥，使用公钥加密并使用私钥解密。如果有人能对此有所了解，将不胜感激。

加密.py

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

from Crypto.PublicKey.pubkey import pubkey

def privKEY():
    private_key = RSA.generate(4096)
    return private_key

def pubKey():
    public_Key = privKEY().publickey()
    return public_Key

def convertPrivKey():
    private_pem = privKEY().exportKey().decode()
    with open('private_pem.pem','w') as pr:
        pr.write(private_pem)
    return private_pem

def convertPubKey():
    public_pem = pubKey().exportKey().decode()
    with open('public_pem.pem','w') as pu:
        pu.write(public_pem)
    return public_pem

def encrypt():
    privKEY()
    pubKey()
    convertPrivKey()
    convertPubKey()
    message = 'Testing RSA Encryption'
    message = message.encode()
    pu_key = RSA.importKey(open('public_pem.pem','r').read())
    print(pu_key)
    cipher = PKCS1_OAEP.new(pu_key)
    cipher_text = cipher.encrypt(message)
    with open('secret.txt','w') as f:
        f.write(str(cipher_text))
encrypt()

解密.py

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

def load_secure_file():
    return open('secret.txt','r').read()

def pr_key_read():
    pr_key = RSA.importKey(open('private_pem.pem','r').read())
    return pr_key

def decrypt():
    encrypted_text = load_secure_file()
    pr_key = pr_key_read()
    decrypt = PKCS1_OAEP.new(pr_key)
    decrypted_message = decrypt.decrypt(encrypted_text)
    return decrypted_message
decrypt()

错误：

PS Y:\Python\RSA> & C:/Anaconda/python.exe y:/Python/RSA/decrypt.py
Traceback (most recent call last):
  File "y:/Python/RSA/decrypt.py", line 19, in <module>
    decrypt()
  File "y:/Python/RSA/decrypt.py", line 17, in decrypt
    decrypted_message = decrypt.decrypt(encrypted_text)
  File "C:\Anaconda\lib\site-packages\Crypto\Cipher\PKCS1_OAEP.py", line 195, in decrypt
    raise ValueError("Ciphertext with incorrect length.")
ValueError: Ciphertext with incorrect length.

新错误：

Traceback (most recent call last):
  File "y:/Python/RSA/decrypt.py", line 19, in <module>
    decrypt()
  File "y:/Python/RSA/decrypt.py", line 14, in decrypt
    encrypted_text = load_secure_file()
  File "y:/Python/RSA/decrypt.py", line 7, in load_secure_file
    return open('secret.txt','r').read()
  File "C:\Anaconda\lib\encodings\cp1252.py", line 23, in decode
    return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x8d in position 30: character maps to <undefined>

Answer 1

Topaco 是对的：您实际上是在生成 四个 密钥对，丢弃前两个，从第三个写入私钥，从第四个写入公钥。这些键不匹配，因此不起作用。您应该生成 一个 密钥对并使用 那个 对的私有和公共部分。以下稍微简化的代码对我有用：

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

# privKEY,pubKey
private_key = RSA.generate(2048) # shortened for testing
public_key = private_key.publickey()
# 'convert' really store
with open('private.pem','w') as pr:
  pr.write(private_key.exportKey().decode())
with open('public.pem','w') as pu:
  pu.write(public_key.exportKey().decode())

# encrypt
message = 'Testing RSA'.encode()
pu_key = RSA.importKey(open('public.pem','r').read())
ciphertext = PKCS1_OAEP.new(pu_key).encrypt(message)
with open('secret.txt','wb') as f:
  f.write(ciphertext)

# decrypt
ciphertext = open('secret.txt','rb').read()
pr_key = RSA.importKey(open('private.pem','r').read())
decrypted = PKCS1_OAEP.new(pr_key).decrypt(ciphertext)
print(decrypted)

-->
b'Testing RSA'

这仅适用于有限数据量的警告仍然存在。