Thread: Reading a file with Courier New characters

  1. #1
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    Unhappy Reading a file with Courier New characters

    Hi to who ever can help...

    I am busy writing an encryption engine that reads a file programmed using VHDL and encrypting it. My problem is that the file uses characters. I managed to find these characters in Word document under Courier New symbols. My encryption engine works on 8 bytes blocks, meaning that I read 8 bytes, encrypt them and save them to the output file. If I read the file using a char variable, the file is not read at all. If I use an int variable it reads and encrypt the file but I am not sure that the encryption operation is then correct because the manipulation of the data now deals with 8 integers and not 8 char characters... Any suggestions? Does anyone know how long are these characters? Can I read them as integers and then convert them to single chars? If yes then how long is an int variable in Visual C++? Any help will be really appreciated!!!

    Thanks, Noam.
    Last edited by Noam; 07-07-2006 at 03:52 AM. Reason: Correction...

  2. #2
    and the hat of int overfl Salem's Avatar
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    > meaning that I read 8 bytes, encrypt them and save them to the output file
    If you're doing
    FILE *fp = fopen("file","rb");

    And to read the file
    unsigned char buff[8];
    fread( buff, 8, 1, fp );

    Then there is nothing to worry about. Any half-decent encryption shouldn't give a monkeys what the data in the file is.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

  3. #3
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    Thanks for the replay!!! I actualy managed to work it through!!!
    I have a new problem though with the fputc function...
    It seemes like there is a slip protocol that addes "stuffing" bytes to the saved message. Is there any way around it? If not are you familiar with the slip protocol - If I knew when a stuffing byte is added I could ignore it on the other side....

    Thanks again, Noam.

  4. #4
    and the hat of int overfl Salem's Avatar
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    Why would the protocol matter?
    Whatever gets added by the protocol to "wrap" up the message going out should be removed when the message is received.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

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