Hi devendra, it's not necessary to wrap around the characters in caeser cipher by taking a modulus like you pointed out, there are many variants of it. Anyways my actual problem is that the encrypted data is not being written into the file whereas if I don't make a call to the encrypt function then the contents are written perfectly to the files.
On 5:25pm, Fri 30-Jan-2015 devendra.aaru <[email protected]> wrote: > On Fri, Jan 30, 2015 at 6:48 AM, Kunal Baweja <[email protected]> > wrote: > >> Yeah I was trying something similar only but with a much simpler Caeser >> cipher function of my own written as below: >> >> void encrypt(char *data, char *encrypted, size_t size) >> { >> unsigned int i; >> for(i=0;i<(unsigned int)size;i++) >> encrypted[i] = data[i] + 3; >> > > This is not caesar's cipher. If your buffer contains alphabets then only > you can apply caesar cipher. > > It should be something like > > encrypted[i] = (data[i] - 3) % 26; > > > >> printk(KERN_INFO "%s",encrypted); >> return; >> } >> >> So in the given code wherever u see the calls to *wrapfs_encrypt*, I >> have replaced with my simpler encryption function. >> >> But I am not able to figure out why calling this function creates a >> problem, the printk() statement inside the function shows me the correctly >> encrypted contents but the file is still blank. >> >> Thanks >> >> *Kunal Baweja* >> >> Undergraduate B.E. (Hons.) Computer Science >> Birla Institute Of Technology & Science, Pilani >> K.K. Birla Goa Campus >> +91 9049655665 >> >> On Fri, Jan 30, 2015 at 4:03 PM, Saket Sinha <[email protected]> >> wrote: >> >>> HI, >>> >>> Kindly refer the following link that implements a minimal encryption >>> over wrapfs. >>> https://github.com/piekill/wrapfs >>> >>> Go through the wrapfs_encrypt in wrapfs_readpage and wrapfs_decrypt in >>> wrapfs_writepage. >>> >>> Regards, >>> Saket Sinha >>> >>> On Fri, Jan 30, 2015 at 3:56 PM, Kunal Baweja <[email protected]> >>> wrote: >>> >>>> Hi, >>>> I am currently working on implementing a simple encrypted file system >>>> using a stackable file system WrapFS <http://wrapfs.filesystems.org/>. >>>> In order to do so, as I read in the WrapFS mailing list >>>> <http://www.fsl.cs.sunysb.edu/pipermail/wrapfs/2011-November/000058.html> >>>> one needs to implement address space operations, which I have done and >>>> posted on my github at this link >>>> <https://github.com/bawejakunal/wrapfs-addresspace-operations/blob/master/mmap.c> >>>> and it works fine. But now when I am trying to modify the data before being >>>> written in wrapfs_lower() function I get a blank output in files written >>>> out. >>>> Please guide where am I going wrong in modifying the data to be written >>>> and what could be the best way to decrypt it ? >>>> >>>> Thanks >>>> >>>> *Kunal Baweja* >>>> >>>> Undergraduate B.E. (Hons.) Computer Science >>>> Birla Institute Of Technology & Science, Pilani >>>> K.K. Birla Goa Campus >>>> +91 9049655665 >>>> >>>> _______________________________________________ >>>> Kernelnewbies mailing list >>>> [email protected] >>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >>>> >>>> >>> >> >> _______________________________________________ >> Kernelnewbies mailing list >> [email protected] >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> >>
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