Python之代码片段-AES加解密

pip install pycryptodome

import base64
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad


class AESCipher:
    """AES加解密类（字符串）"""
    def __init__(self, key, iv):
        """
        初始化
        :param key: 密钥（16/24/32字节对应的AES-128/192/256）
        """
        # 确保密钥长度是16、24或32字节
        if isinstance(key, str):
            key = key.encode('utf-8')
        if len(key) not in [16, 24, 32]:
            raise ValueError("密钥长度必须是16、24或32字节")
        self.key = key
        self.iv = iv.encode('utf-8')

    def encrypt(self, text):
        """
        加密字符串
        :param text: 要加密的字符串
        :return: base64编码的密文字符串
        """
        result = None
        try:
            # 字符串转字节
            if isinstance(text, str):
                text = text.encode('utf-8')
            # 创建CBC模式加密器（使用固定IV，实际使用建议随机生成）
            cipher = AES.new(self.key, AES.MODE_CBC, self.iv)
            # 加密并返回base64
            encrypted = cipher.encrypt(pad(text, AES.block_size))
            result = base64.b64encode(encrypted).decode('utf-8')
        except Exception as e:
            print(f"加密失败: {str(e)}")
        return result

    def decrypt(self, text):
        """
        解密字符串
        :param text: base64编码的密文字符串
        :return: 解密后的明文字符串
        """
        result = None
        try:
            # base64解码
            encrypted = base64.b64decode(text)
            # 创建解密器
            cipher = AES.new(self.key, AES.MODE_CBC, self.iv)
            # 解密并去除填充
            decrypted = unpad(cipher.decrypt(encrypted), AES.block_size)
            result = decrypted.decode('utf-8')
        except Exception as e:
            print(f"解密失败: {str(e)}")
        return result


# KEY 和 IV 长度固定；内容可变
KEY = "99999999999999999999999999999999"
IV = "123456789012345x"
aes_cipher = AESCipher(KEY, IV)

# 使用示例
if __name__ == "__main__":
    # 加密
    plain = "Hello World"
    encrypted_text = aes_cipher.encrypt(plain)
    print(f"原文: {plain}")
    print(f"加密: {encrypted_text}")

    # 解密
    decrypted_text = aes_cipher.decrypt(encrypted_text)
    print(f"解密: {decrypted_text}")