from cryptography.fernet import Fernet

# 生成密钥
key = Fernet.generate_key()

# 创建Fernet对象
fernet = Fernet(key)

# 加密明文
plaintext = b"Hello, world!"
ciphertext = fernet.encrypt(plaintext)
print("密文：", ciphertext)

# 解密密文
decrypted_text = fernet.decrypt(ciphertext)
print("明文：", decrypted_text.decode())

from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.backends import default_backend

# 生成密钥对
private_key = rsa.generate_private_key(
    public_exponent=65537,
    key_size=2048,
    backend=default_backend()
)
public_key = private_key.public_key()

# 将密钥序列化为PEM格式
private_pem = private_key.private_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PrivateFormat.PKCS8,
    encryption_algorithm=serialization.NoEncryption()
)
public_pem = public_key.public_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PublicFormat.SubjectPublicKeyInfo
)

# 加密明文
plaintext = b"Hello, world!"
ciphertext = public_key.encrypt(
    plaintext,
    padding.OAEP(
        mgf=padding.MGF1(algorithm=hashes.SHA256()),
        algorithm=hashes.SHA256(),
        label=None
    )
)
print("密文：", ciphertext)

# 解密密文
decrypted_text = private_key.decrypt(
    ciphertext,
    padding.OAEP(
        mgf=padding.MGF1(algorithm=hashes.SHA256()),
        algorithm=hashes.SHA256(),
        label=None
    )
)
print("明文：", decrypted_text.decode())