86 lines
2.9 KiB
Python
86 lines
2.9 KiB
Python
from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
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from cryptography.hazmat.backends import default_backend
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from cryptography.hazmat.primitives import padding
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class MyAES:
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def __init__(self, key: str, iv: str):
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self.key: bytes = bytes.fromhex(key)
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self.iv: bytes = bytes.fromhex(iv)
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def decrypt(self, ciphertext: str):
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cipher: bytes = bytes.fromhex(ciphertext)
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plain: bytes = MyAES.aes_decrypt(cipher, self.key, self.iv)
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try:
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return plain.decode('utf-8')
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except UnicodeDecodeError as e:
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# 返回原始字节的十六进制表示作为备选
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return plain.hex()
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def encrypt(self, original_text: str):
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plaintext: byte = original_text.encode('utf-8')
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ciphertext: byte = MyAES.aes_encrypt(plaintext, self.key, self.iv)
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return ciphertext.hex()
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@staticmethod
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def aes_decrypt(ciphertext: bytes, key: bytes, iv: bytes) -> bytes:
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"""
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使用AES-256-CBC算法解密数据
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参数
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- ciphertext: 待解密的密文字节串
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- key: 256位（32字节）的密钥字节串
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- iv: 初始化向量字节串（必须为16字节）
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返回：
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- 解密后的明文字节串
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"""
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# 验证输入参数长度
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if len(key) != 32:
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raise ValueError('AES-256密钥必须是32字节长度')
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if len(iv) != 16:
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raise ValueError('AES-CBC的IV必须是16字节长度')
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# 创建AES-CBC解密器
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cipher = Cipher(algorithms.AES(key), modes.CBC(iv), backend=default_backend())
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decryptor = cipher.decryptor()
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try:
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# 执行解密并移除PKCS#7填充
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plaintext = decryptor.update(ciphertext) + decryptor.finalize()
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return plaintext
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except Exception as e:
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print(f"解密失败：{e}")
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return b''
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@staticmethod
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def aes_encrypt(plaintext: bytes, key: bytes, iv: bytes) -> bytes:
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"""
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AES-256-CBC 加密
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参数
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plaintext: 要加密的密文
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key: 32字节的密钥
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iv: 16字节的初始化向量
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返回：
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加密后的密文
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"""
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# 检查密钥和IV的长度
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if len(key) != 32:
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raise ValueError("密钥必须是32字节（AES-256）")
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if len(iv) != 16:
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raise ValueError("IV必须是16字节")
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# 创建加密器
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cipher = Cipher(
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algorithms.AES(key),
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modes.CBC(iv),
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backend=default_backend()
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)
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encryptor = cipher.encryptor()
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# 添加PKCS7填充
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padder = padding.PKCS7(128).padder()
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padded_data = padder.update(plaintext) + padder.finalize()
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# 加密数据
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ciphertext = encryptor.update(padded_data) + encryptor.finalize()
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return ciphertext
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