[PATCH] using crypto API in WEP

Pedro Ramalhais ramalhais at serrado.net
Wed May 26 23:38:38 EDT 2004

Hi Jouni!
Attached is a patch to add support for using the kernel's crypto API.
I am aware of the (small?) performance penalty in going through the data
twice, but i didn't see any difference transferring at 600K/s.
The decryption implementation is somewhat unusual. Instead of decrypting
the encrypted data, calculating the CRC32, encrypting the CRC32 and
comparing with the received ICV, i do the following: decrypt the
encrypted data and the ICV, calculate the CRC32 on the unencrypted data
and compare it with the unencrypted ICV. I did it this way because the
code looked simpler. I had some doubts about the security implications
of this alteration and talked about it with one of my university
teachers, and as far as i understood there are no problems in doing
this. Anyway the code can be easily modified to do it the usual way.
I have only tested this code with the ipw2100 driver (it uses hostap for
the WEP part).
I hope this patch is of any utility for making one more step into having
hostap in the official kernel source.

Pedro Ramalhais <ramalhais at serrado.net>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: hostap-CVS.WEP_CRYPTO_API.patch
Type: text/x-patch
Size: 5325 bytes
Desc: not available
Url : http://lists.shmoo.com/pipermail/hostap/attachments/20040527/62498f30/attachment.bin 

More information about the HostAP mailing list