On Thu, Mar 22, 2007 at 01:13:59AM +0100, Nicolas Boullis wrote:

First of all, sorry to bother you. I thought I'd rather ask my question 
to a list dedicated to the crypto API, but only found 
linux-crypto@vger.kernel.org that appears to be dead...

Actually that list is alive and well.

I'm working on a linux driver for some hardware MPEG decompression 
boards (see dxr3.sourceforge.net). Those cards have an on-board i2c 
serial EEPROM, and I'd like to compute a hash of the EEPROM's content, 
to mach different card models.

Since it's i2c-based, it can't be memory-mapped, so I think I have to 
first read it into a buffer in kernel memory. But the I have some 
trouble to compute the hash.

It seemed to work correctly, while I used the crypto_digest functions + 
a direct call to the dis_update function of the underlying algorith, 
although it was somewhat hackish...

It still seems to work allocating a crypto_hash transform and then using 
the underlying digest algorith functions, but looks even more hackish.


SO my question is: is there a non-hackish way to compute the hash of a 
kernel buffer? (I thought I'd use md5 but a different one would be as 
fine.)

As long as your kernel buffer is malloced, you can turn it into an
sg list with sg_set_buf.

Once the async interface is in place, it might make sense to convert
all remaining sync users to use an address-based interface instead
of scatter lists.

Cheers,
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