RSApython代码

RSA（Rivest-Shamir-Adleman）是一种非对称加密算法，广泛用于数据加密和数字签名。在Python中，你可以使用`cryptography`库来实现RSA。以下是一个简单的RSA密码学生成密钥对、加密和解密的示例：

from cryptography.hazmat.primitives import serialization, hashes
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives.asymmetric.padding import OAEP, PKCS1v15

# 生成RSA密钥对
def generate_rsa_keys():
    private_key = rsa.generate_private_key(
        public_exponent=65537,
        key_size=2048,
        backend=serialization.default_backend()
    )
    public_key = private_key.public_key()
    return private_key, public_key

# 保存密钥对
def save_keys(private_key, filename="private.pem", public_key=None, filename_public="public.pem"):
    if public_key is None:
        public_key = private_key.public_key()
    with open(filename, "wb") as f:
        private_key_bytes = private_key.private_bytes(
            encoding=serialization.Encoding.PEM,
            format=serialization.PrivateFormat.PKCS8,
            encryption_algorithm=serialization.NoEncryption()
        )
        f.write(private_key_bytes)
    with open(filename_public, "wb") as f:
        public_key_bytes = public_key.public_bytes(
            encoding=serialization.Encoding.PEM,
            format=serialization.PublicFormat.SubjectPublicKeyInfo
        )
        f.write(public_key_bytes)

# 加载密钥对
def load_keys(filename="private.pem", filename_public="public.pem"):
    with open(filename, "rb") as f:
        private_key = serialization.load_pem_private_key(
            data=f.read(),
            password=None,
            backend=serialization.default_backend()
        )
    with open(filename_public, "rb") as f:
        public_key = serialization.load_pem_public_key(
            data=f.read(),
            backend=serialization.default_backend()
        )
    return private_key, public_key

# 加密数据
def encrypt(message, public_key):
    ciphertext = public_key.encrypt(
        message.encode(),
        padding=OAEP(
            mgf=padding.MGF1(algorithm=hashes.SHA256()),
            algorithm=hashes.SHA256(),
            label=None
        )
    )
    return ciphertext

# 解密数据
def decrypt(ciphertext, private_key):
    plaintext = private_key.decrypt(
        ciphertext,
        padding=PKCS1v15()
    )
    return plaintext.decode()

# 示例
private_key, public_key = generate_rsa_keys()
save_keys(private_key, public_key=public_key)
loaded_private_key, loaded_public_key = load_keys()
encrypted_message = encrypt("Hello, RSA!", loaded_public_key)
decrypted_message = decrypt(encrypted_message, loaded_private_key)

print("Original message:", message)
print("Encrypted message:", encrypted_message.hex())
print("Decrypted message:", decrypted_message)