Re: [PATCH v8 08/22] protectors: Add key protectors framework

[Gary Lin]

On Wed, Jan 17, 2024 at 05:58:25AM +0300, Vladimir 'phcoder' Serbinenko wrote:
> Any strong reason to have it in kernel? It doesn't seem to be
> necessary in non-crypto cases. Separate module or cryptodisk looks
> like better places
> 
I have no strong opinion about the location as long as it works.
Will move the key protector to cryptodisk since it's the only user currently.

Gary Lin

> On Tue, Jan 16, 2024 at 12:22 PM Gary Lin via Grub-devel
> <grub-devel@gnu.org> wrote:
> >
> > From: Hernan Gatta <hegatta@linux.microsoft.com>
> >
> > A key protector encapsulates functionality to retrieve an unlocking key
> > for a fully-encrypted disk from a specific source. A key protector
> > module registers itself with the key protectors framework when it is
> > loaded and unregisters when unloaded. Additionally, a key protector may
> > accept parameters that describe how it should operate.
> >
> > The key protectors framework, besides offering registration and
> > unregistration functions, also offers a one-stop routine for finding and
> > invoking a key protector by name. If a key protector with the specified
> > name exists and if an unlocking key is successfully retrieved by it, the
> > function returns to the caller the retrieved key and its length.
> >
> > Signed-off-by: Hernan Gatta <hegatta@linux.microsoft.com>
> > Signed-off-by: Gary Lin <glin@suse.com>
> > ---
> >  grub-core/Makefile.am       |  1 +
> >  grub-core/Makefile.core.def |  1 +
> >  grub-core/kern/protectors.c | 75 +++++++++++++++++++++++++++++++++++++
> >  include/grub/protector.h    | 48 ++++++++++++++++++++++++
> >  4 files changed, 125 insertions(+)
> >  create mode 100644 grub-core/kern/protectors.c
> >  create mode 100644 include/grub/protector.h
> >
> > diff --git a/grub-core/Makefile.am b/grub-core/Makefile.am
> > index f18550c1c..af21fc72d 100644
> > --- a/grub-core/Makefile.am
> > +++ b/grub-core/Makefile.am
> > @@ -90,6 +90,7 @@ endif
> >  KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/mm.h
> >  KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/parser.h
> >  KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/partition.h
> > +KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/protector.h
> >  KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/stack_protector.h
> >  KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/term.h
> >  KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/time.h
> > diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> > index c9d81b56a..70d5e0e00 100644
> > --- a/grub-core/Makefile.core.def
> > +++ b/grub-core/Makefile.core.def
> > @@ -149,6 +149,7 @@ kernel = {
> >    common = kern/misc.c;
> >    common = kern/parser.c;
> >    common = kern/partition.c;
> > +  common = kern/protectors.c;
> >    common = kern/rescue_parser.c;
> >    common = kern/rescue_reader.c;
> >    common = kern/term.c;
> > diff --git a/grub-core/kern/protectors.c b/grub-core/kern/protectors.c
> > new file mode 100644
> > index 000000000..5ee059565
> > --- /dev/null
> > +++ b/grub-core/kern/protectors.c
> > @@ -0,0 +1,75 @@
> > +/*
> > + *  GRUB  --  GRand Unified Bootloader
> > + *  Copyright (C) 2022 Microsoft Corporation
> > + *
> > + *  GRUB 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 3 of the License, or
> > + *  (at your option) any later version.
> > + *
> > + *  GRUB is distributed in the hope that it will be useful,
> > + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + *  GNU General Public License for more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include <grub/list.h>
> > +#include <grub/misc.h>
> > +#include <grub/mm.h>
> > +#include <grub/protector.h>
> > +
> > +struct grub_key_protector *grub_key_protectors = NULL;
> > +
> > +grub_err_t
> > +grub_key_protector_register (struct grub_key_protector *protector)
> > +{
> > +  if (protector == NULL || protector->name == NULL || 
> > grub_strlen(protector->name) == 0)
> > +    return GRUB_ERR_BAD_ARGUMENT;
> > +
> > +  if (grub_key_protectors &&
> > +      grub_named_list_find (GRUB_AS_NAMED_LIST (grub_key_protectors),
> > +                           protector->name))
> > +    return GRUB_ERR_BAD_ARGUMENT;
> > +
> > +  grub_list_push (GRUB_AS_LIST_P (&grub_key_protectors),
> > +                 GRUB_AS_LIST (protector));
> > +
> > +  return GRUB_ERR_NONE;
> > +}
> > +
> > +grub_err_t
> > +grub_key_protector_unregister (struct grub_key_protector *protector)
> > +{
> > +  if (protector == NULL)
> > +    return GRUB_ERR_BAD_ARGUMENT;
> > +
> > +  grub_list_remove (GRUB_AS_LIST (protector));
> > +
> > +  return GRUB_ERR_NONE;
> > +}
> > +
> > +grub_err_t
> > +grub_key_protector_recover_key (const char *protector, grub_uint8_t **key,
> > +                               grub_size_t *key_size)
> > +{
> > +  struct grub_key_protector *kp = NULL;
> > +
> > +  if (grub_key_protectors == NULL)
> > +    return GRUB_ERR_OUT_OF_RANGE;
> > +
> > +  if (protector == NULL || grub_strlen (protector) == 0)
> > +    return GRUB_ERR_BAD_ARGUMENT;
> > +
> > +  kp = grub_named_list_find (GRUB_AS_NAMED_LIST (grub_key_protectors),
> > +                            protector);
> > +  if (kp == NULL)
> > +    return grub_error (GRUB_ERR_OUT_OF_RANGE,
> > +                      N_("A key protector with name '%s' could not be 
> > found. "
> > +                         "Is the name spelled correctly and is the "
> > +                         "corresponding module loaded?"), protector);
> > +
> > +  return kp->recover_key (key, key_size);
> > +}
> > diff --git a/include/grub/protector.h b/include/grub/protector.h
> > new file mode 100644
> > index 000000000..3d9f69bce
> > --- /dev/null
> > +++ b/include/grub/protector.h
> > @@ -0,0 +1,48 @@
> > +/*
> > + *  GRUB  --  GRand Unified Bootloader
> > + *  Copyright (C) 2022 Microsoft Corporation
> > + *
> > + *  GRUB 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 3 of the License, or
> > + *  (at your option) any later version.
> > + *
> > + *  GRUB is distributed in the hope that it will be useful,
> > + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + *  GNU General Public License for more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#ifndef GRUB_PROTECTOR_HEADER
> > +#define GRUB_PROTECTOR_HEADER 1
> > +
> > +#include <grub/err.h>
> > +#include <grub/types.h>
> > +
> > +struct grub_key_protector
> > +{
> > +  struct grub_key_protector *next;
> > +  struct grub_key_protector **prev;
> > +
> > +  const char *name;
> > +
> > +  grub_err_t (*recover_key) (grub_uint8_t **key, grub_size_t *key_size);
> > +};
> > +
> > +extern struct grub_key_protector *EXPORT_VAR (grub_key_protectors);
> > +
> > +grub_err_t
> > +EXPORT_FUNC (grub_key_protector_register) (struct grub_key_protector 
> > *protector);
> > +
> > +grub_err_t
> > +EXPORT_FUNC (grub_key_protector_unregister) (struct grub_key_protector 
> > *protector);
> > +
> > +grub_err_t
> > +EXPORT_FUNC (grub_key_protector_recover_key) (const char *protector,
> > +                                             grub_uint8_t **key,
> > +                                             grub_size_t *key_size);
> > +
> > +#endif /* ! GRUB_PROTECTOR_HEADER */
> > --
> > 2.35.3
> >
> >
> > _______________________________________________
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> > Grub-devel@gnu.org
> > https://lists.gnu.org/mailman/listinfo/grub-devel
> 
> 
> 
> -- 
> Regards
> Vladimir 'phcoder' Serbinenko