def file_decrypt(encrypted_filepath, key_encrypted, iv_encrypted):
"""
对文件进行解密
:param encrypted_file_path: 加密文件的路径
:param key_encrypted: 加密的密钥
:param iv_encrypted: 加密的iv
:return: 解密后文件路径, 解密后文件的md5
"""
# 先用server的私钥对key和iv进行解密
key = RSA.Decrypto(key_encrypted, client_d, client_n)
iv = RSA.Decrypto(iv_encrypted, client_d, client_n)
# 打开并读取加密文件
encrypted_file = open(encrypted_filepath, 'rb')
encrypted_filedata = encrypted_file.read().decode('latin')
# 去掉.crypted后缀
origin_filepath = ".".join(encrypted_filepath.split('.')[:-1])
# 将解密后的内容写入新文件
origin_file = open(origin_filepath, 'wb')
origin_file.write(
DES.des_cbc_decrypt(encrypted_filedata, libnum.n2s(key),
libnum.n2s(iv)).encode('latin'))
# 关闭文件指针
encrypted_file.close()
origin_file.close()
# 计算解密后文件的md5消息摘要
origin_file_digest = get_file_md5(origin_filepath)
return origin_filepath, origin_file_digest
def file_encrypt(filepath):
"""
对文件进行DES-CBC加密,并用RSA加密key和iv
:param filepath: 原文件路径
:return: 加密文件路径, 原文件md5值, 加密后的key, 加密后的iv
"""
# 随机生成key和iv
key, iv = get_des_param()
# 打开原文件
origin_file = open(filepath, 'rb')
origin_filedata = origin_file.read().decode('latin')
# 计算原文件的消息摘要
origin_digest = md5(origin_filedata)
# 加密后文件的地址(统一加上.encrypted后缀)
encrypted_filepath = filepath + ".encrypted"
# 写入加密文件
encrypted_file = open(encrypted_filepath, 'wb')
encrypted_file.write(
DES.des_cbc_encrypt(origin_filedata, key, iv).encode('latin'))
# 关闭文件
origin_file.close()
encrypted_file.close()
# 用client的公钥对key和iv进行加密
key_encrypted = RSA.Encrypt(libnum.s2n(key), server_e, server_n)
iv_encrypted = RSA.Encrypt(libnum.s2n(iv), server_e, server_n)
return encrypted_filepath, origin_digest, key_encrypted, iv_encrypted
def transfer_encrypt(message):
"""
对分组传输的每一个分组进行des_cbc加密,且每次使用不同的key和iv
:param message: 被加密的分组
:return: key,iv,cipher
"""
key, iv = get_des_param()
cipher = DES.des_cbc_encrypt(message, key, iv, 'b')
# 用server的公钥对key和iv进行加密
key_encrypted = RSA.Encrypt(libnum.s2n(key), server_e, server_n)
iv_encrypted = RSA.Encrypt(libnum.s2n(iv), server_e, server_n)
return key_encrypted, iv_encrypted, cipher
def transfer_decrypt(cipehr, key_encrypted, iv_encrypted):
"""
对接收到的每一个分组进行解密
:param cipehr: 收到的加密分组
:param key_encrypted: 收到的加密过的key
:param iv_encrypted: 收到的加密过的iv
:return: 明文
"""
# 先用client的私钥对key和iv进行解密
key = RSA.Decrypto(key_encrypted, client_d, client_n)
iv = RSA.Decrypto(iv_encrypted, client_d, client_n)
# 用key和iv对收到的密文分组解密
message = DES.des_cbc_decrypt(cipehr, libnum.n2s(key), libnum.n2s(iv), 'b')
return message