Re: [PATCH 6/6] ima-evm-utils: define a basic hash_info.h file

[Mimi Zohar <zohar@linux.ibm.com>]

On Wed, 2020-07-15 at 14:58 -0300, Bruno Meneguele wrote:
> Hi Mimi,
> 
> On Mon, Jul 06, 2020 at 10:26:31PM -0400, Mimi Zohar wrote:
> > Some older system kernel header packages don't necessarily include
> > hash_info.h.
> > 
> > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
> > ---
> >  src/Makefile.am   |  2 +-
> >  src/hash_info.gen | 43 +++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 44 insertions(+), 1 deletion(-)
> > 
> > diff --git a/src/Makefile.am b/src/Makefile.am
> > index 36652427a8ec..9bbff5034ef4 100644
> > --- a/src/Makefile.am
> > +++ b/src/Makefile.am
> > @@ -34,5 +34,5 @@ endif
> >  
> >  AM_CPPFLAGS = -I$(top_srcdir) -include config.h
> >  
> > -CLEANFILES = hash_info.h
> > +CLEANFILES = hash_info.h tmp_hash_info.h
> >  DISTCLEANFILES = @DISTCLEANFILES@
> > diff --git a/src/hash_info.gen b/src/hash_info.gen
> > index 54532ca5b847..5f7a97fb3117 100755
> > --- a/src/hash_info.gen
> > +++ b/src/hash_info.gen
> > @@ -18,11 +18,54 @@ KERNEL_HEADERS=$1
> >  HASH_INFO_H=uapi/linux/hash_info.h
> >  HASH_INFO=$KERNEL_HEADERS/include/$HASH_INFO_H
> >  
> > +TMPHASHINFO="./tmp_hash_info.h"
> > +gen_hashinfo() {
> > +cat << __EOF__ >$TMPHASHINFO
> > +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
> > +/*
> > + * Hash Info: Hash algorithms information
> > + *
> > + * Copyright (c) 2013 Dmitry Kasatkin <d.kasatkin@samsung.com>
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms of the GNU General Public License as published by the Free
> > + * Software Foundation; either version 2 of the License, or (at your option)
> > + * any later version.
> > + *
> > + */
> > +
> > +enum hash_algo {
> > +	HASH_ALGO_MD4,
> > +	HASH_ALGO_MD5,
> > +	HASH_ALGO_SHA1,
> > +	HASH_ALGO_RIPE_MD_160,
> > +	HASH_ALGO_SHA256,
> > +	HASH_ALGO_SHA384,
> > +	HASH_ALGO_SHA512,
> > +	HASH_ALGO_SHA224,
> > +	HASH_ALGO_RIPE_MD_128,
> > +	HASH_ALGO_RIPE_MD_256,
> > +	HASH_ALGO_RIPE_MD_320,
> > +	HASH_ALGO_WP_256,
> > +	HASH_ALGO_WP_384,
> > +	HASH_ALGO_WP_512,
> > +	HASH_ALGO_TGR_128,
> > +	HASH_ALGO_TGR_160,
> > +	HASH_ALGO_TGR_192,
> > +	HASH_ALGO_SM3_256,
> > +	HASH_ALGO__LAST
> > +};
> > +__EOF__
> 
> Just a minor point on HASH_ALGO_SM3_256:
> 
> The old kernels that didn't export hash_info.h uapi didn't support
> HASH_ALGO_SM3_256 as well. Wouldn't it be better to also not include it
> in the tmp_hash_info considering it'll be used only by those running
> older kernels without SM3 support?
> 
> Keeping it won't cause any issues though. So I'm fine with it either
> way.

I was debating which version to use, but couldn't decide.

For distros that probably is true, but I'm not sure about embedded.
 Commit ceecb28d3b52 ("ima-evm-utils: add SM3 to pkey_hash_algo
algorithm list") updated pkey_hash_algo[].

As it doesn't hurt, let's just keep it.

Mimi