Re: [PATCH] keys, trusted: select TPM2 hash algorithm

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

n Mon, Oct 26, 2015 at 07:44:39AM +0200, Jarkko Sakkinen wrote:
> On Sun, Oct 25, 2015 at 03:21:31PM -0400, Mimi Zohar wrote:
> > On Sat, 2015-10-24 at 15:42 +0300, Jarkko Sakkinen wrote:
> > > Added 'hashalg=' option for selecting the hash algorithm.
> > > 
> > > Currently available options are:
> > > 
> > > * sha1
> > > * sha256
> > > * sha384
> > > * sha512
> > > * sm3_256
> > 
> > Please consider using crypto/hash_info.c: hash_algo_name[], which
> > already define the algorithm string names.  Use
> > include/crypto/hash_info.c to include a reference to this array.
> 
> It wold work for me. I did ad-hoc because first example that I looked
> at was EcryptFS.
> 
> I need to add sm3_256 to that array.
> 
> I've found three different ways to write it:
> 
> * sm3256 (various google hits)
> * sm3-256 (various google hits)
> * sm3_256 (TPM 2.0 Structures specification)
> 
> Maybe the second option would be the most appropriate?
> 
> > Boot command line options should be prefixed with the subsystem name.
> > So instead of hashalg, please use tpm_hashalg.  The boot command line
> > option needs to be documented in Documentation/kernel-parameters.txt.
> 
> I see. My commit message is clearly inadequate. It's an option for the
> keyring syscalls.

BTW, in IMA I see you have the hash algorithm as a boot parameter. I
guess it makes sense there because it works implicitly in the
background?

Sealing a trusted key is an explicit operation. That's why I thought
it'd be better to have it as an option for the syscall. Does this logic
make sense to your or not?

> > Mimi

PS. Hey one more thing: this was supposed to be RFC, forgot to add
--subject-prefix="PATCH RFC". Sorry about that.

> /Jarkko

/Jarkko