为什么 PyCrypto 不允许使用私有编码和使用 public 密钥解码来验证发件人身份

Question

我一直在研究 PyCrypto 库，目的是制作一个像这样工作的系统：

为发送方和接收方创建一个 RSA 密钥集和一个单独的 AES 密钥
发件人：
1. 使用 ECB 加密模式 ECB
2. 使用发件人私钥加密 AES 密钥
3. 将自己的名字连接到最后一步的结果
4. 使用接收方 public 密钥
5. 将第 1 步和第 4 步的结果合并为 1 条消息并将其发送给接收方
和接收器
1. 将消息拆分为实际消息和双重加密密钥（其中还包含发件人姓名）
2. 使用自己的私钥解密双重加密的密钥
3. 使用发件人的姓名检索发件人public 密钥
4. 使用发件人 public 密钥解密 AES 密钥
5. 使用 AES 密钥解密消息

但是我在双重加密方面遇到了问题。问题是当使用私钥加密时，我无法使用 public 密钥解密某些内容。我知道这是因为 ARS 不应该向后工作，但我想这样做是为了向接收者验证发送者的身份。我不知道该怎么做。

这是当前代码（我知道它很乱，我是 python 的初学者，对加密完全陌生）：

from Crypto import Random
from Crypto.PublicKey import RSA
from Crypto.Cipher import AES, PKCS1_OAEP
from termcolor import colored
import base64, os


def generate_keys_rsa():
    modulus_length = 256*4
    privatekey = RSA.generate(modulus_length, Random.new().read)
    publickey = privatekey.publickey()
    return privatekey, publickey


def encrypt_message_rsa(a_message, publickey):
    encryptor = PKCS1_OAEP.new(publickey)
    encrypted_msg = encryptor.encrypt(a_message)
    encoded_encrypted_msg = base64.b64encode(encrypted_msg)
    return encoded_encrypted_msg


def decrypt_message_rsa(encoded_encrypted_msg, privatekey):
    decoded_msg = base64.b64decode(encoded_encrypted_msg)
    decryptor = PKCS1_OAEP.new(privatekey)
    decoded_decrypted_msg = decryptor.decrypt(decoded_msg)
    return decoded_decrypted_msg


def generate_key_aes():
    aes_key_length = 32
    secret_key = os.urandom(aes_key_length)
    encoded_secret_key = base64.b64encode(secret_key)
    return encoded_secret_key


def encrypt_message_aes(private_msg, encoded_secret_key, padding_character):
    secret_key = base64.b64decode(encoded_secret_key)
    cipher = AES.new(secret_key, AES.MODE_ECB)
    padded_private_msg = private_msg + (padding_character * ((16 - len(private_msg)) % 16))
    encrypted_msg = cipher.encrypt(padded_private_msg.encode("utf-8"))
    encoded_encrypted_msg = base64.b64encode(encrypted_msg)
    return encoded_encrypted_msg


def decrypt_message_aes(encoded_encrypted_msg, encoded_secret_key, padding_character):
    secret_key = base64.b64decode(encoded_secret_key)
    cipher = AES.new(secret_key, AES.MODE_ECB)
    encrypted_msg = base64.b64decode(encoded_encrypted_msg)
    decrypted_msg = cipher.decrypt(encrypted_msg)
    unpadded_private_msg = decrypted_msg.rstrip(padding_character)
    return unpadded_private_msg.decode("ascii")


#         PROCESS         #
# 'rec' means 'received'  #
# 'enc' means 'encrypted' #
# 'dec' means 'decrypted' #
# 'pad' means 'padding'   #
# 'div' means 'division'  #
#         PROCESS         #

raw_txt = input("Message to send: ")
txt = str(raw_txt)

pad_char = "{"
div_char = "|"

# ASSEMBLY #
privatekey0_RSA , publickey0_RSA = generate_keys_rsa()
privatekey1_RSA , publickey1_RSA = generate_keys_rsa()
key_AES = generate_key_aes()

enc_txt = encrypt_message_aes(txt, key_AES, pad_char)
enc_key = encrypt_message_rsa(key_AES, privatekey0_RSA)

msg = (
        pad_char.encode("utf-8") +
        div_char.encode("utf-8") +
        enc_txt +
        div_char.encode("utf-8") +
        enc_key
)

# DISASSEMBLY #
rec_pad = msg[: 1]
rec_div = chr(msg[1])
rec_enc_txt = msg[2: (msg[2:].find(rec_div.encode("utf-8")) + 2)]
rec_enc_key = msg[(msg[2:].find(rec_div.encode("utf-8")) + 3):]
rec_dec_key = decrypt_message_rsa(rec_enc_key, publickey0_RSA)
rec_dec_txt = decrypt_message_aes(rec_enc_txt, rec_dec_key, rec_pad)

# RESULT LOG #
print()
print(colored("Total message: ", "blue", None, ["bold"]), "%s" % msg)
print()
print(colored(" Original key_AES: ", "blue", None, ["bold"]), "%s - (%d)" % (key_AES, len(key_AES)))
print(colored("Encrypted key_AES: ", "blue", None, ["bold"]), "%s - (%d)" % (enc_key, len(enc_key)))
print(colored("Decrypted key_AES: ", "blue", None, ["bold"]), "%s - (%d)" % (rec_dec_key, len(rec_dec_key)))
print(colored("Decrypted key_AES == Original key_AES: ", "blue", None, ["bold"]), colored("%s" % (rec_dec_key == key_AES), "green" if (rec_dec_key == key_AES) else "red", None, ["bold"]))
print()
print(colored(" Original text: ", "blue", None, ["bold"]), "%s - (%d)" % (txt, len(txt)))
print(colored("Encrypted text: ", "blue", None, ["bold"]), "%s - (%d)" % (enc_txt, len(enc_txt)))
print(colored("Decrypted text: ", "blue", None, ["bold"]), "%s - (%d)" % (rec_dec_txt, len(rec_dec_txt)))
print(colored("Decrypted text == Original text: ", "blue", None, ["bold"]), colored("%s" % (rec_dec_txt == txt), "green" if (rec_dec_txt == txt) else "red", None, ["bold"]))

那么，您知道向后使用 ARS 的解决方案，还是验证发件人身份的替代方法吗？

Answer 1

an alternative way of verifying the senders identity

会不会是 digital signature? It is supported by PyCryptodome and uses RSA.

为什么 PyCrypto 不允许使用私有编码和使用 public 密钥解码来验证发件人身份

Why doesn't PyCrypto allow for encoding with the private and decoding with the public key to verify the sendersidentity

python

encryption

aes

pycrypto

encryption-asymmetric