Python之RSA加密 解密 签名 验证

from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
from Crypto.Signature import PKCS1_v1_5 as Signature_pkcs1_v1_5
from Crypto.Hash import SHA256
from base64 import b64encode, b64decode
 
# 生成RSA密钥对
key = RSA.generate(2048)
public_key = key.publickey()
 
# 加密
def encrypt(text):
    cipher = Cipher_pkcs1_v1_5.new(public_key)
    return b64encode(cipher.encrypt(text.encode('utf-8'))).decode('utf-8')
 
# 解密
def decrypt(text):
    cipher = Cipher_pkcs1_v1_5.new(key)
    return cipher.decrypt(b64decode(text.encode('utf-8')), b'').decode('utf-8')
 
# 签名
def sign(text):
    h = SHA256.new()
    h.update(text.encode('utf-8'))
    signer = Signature_pkcs1_v1_5.new(key)
    return b64encode(signer.sign(h)).decode('utf-8')
 
# 验证签名
def verify(text, signature):
    h = SHA256.new()
    h.update(text.encode('utf-8'))
    verifier = Signature_pkcs1_v1_5.new(public_key)
    return verifier.verify(h, b64decode(signature.encode('utf-8')))
 
# 使用示例
plaintext = "Hello, World!"
encrypted = encrypt(plaintext)
decrypted = decrypt(encrypted)
signed_data = sign(plaintext)
print(f"Original: {plaintext}")
print(f"Encrypted: {encrypted}")
print(f"Decrypted: {decrypted}")
print(f"Signed: {signed_data}")
assert verify(plaintext, signed_data), "Signature verification failed"
print("Signature verified successfully")

这段代码展示了如何使用PyCrypto库进行RSA加密、解密、签名和验证。首先生成了一个2048位的RSA密钥对，然后提供了encrypt、decrypt、sign和verify函数来执行这些操作。最后，我们用一个示例来展示如何使用这些函数。