文件加密程序

1．　　对指定的文本文件进行加密（应判断其是否已经加密，若已加密则结束该步骤，否则提示输入加密口令，对文件进行加密）；

2．　　加密解密方法：输入一个6字符的密钥，将文件数据和密钥进行异或运算。不足6字节的部分，和密钥相应的位进行运算。加密解密方法一样。

3、加密解密后，将数据重新写入文件。

-an encrypted document. For the specified text file encryption (should judge whether encryption, encrypted if it is the end of the steps Otherwise suggest the import of encryption password, encryption of documents); 2. Encryption and decryption : Admission of a six key characters, data and documents will be key for XOR operation. 600 bytes of, and the corresponding key bits operation. Encryption and decryption of the same. 3, encryption, decryption, the data will be re-incorporated.