On Tue, 2019-01-15 at 17:56 -0800, Dan Williams wrote:
> Some comments below...
> 
> On Mon, Jan 14, 2019 at 12:06 PM Dave Jiang <dave.ji...@intel.com> wrote:
> > 
> > Add API call for triggering sysfs knob to update the security for a DIMM
> > in libndctl. Also add the ndctl "update-passphrase" to trigger the
> > operation.
> > 
> > Signed-off-by: Dave Jiang <dave.ji...@intel.com>
> > ---
> >  Documentation/ndctl/Makefile.am                 |    4
> >  Documentation/ndctl/ndctl-enable-passphrase.txt |   42 ++
> >  Documentation/ndctl/ndctl-update-passphrase.txt |   38 ++
> >  configure.ac                                    |   19 +
> >  ndctl.spec.in                                   |    2
> >  ndctl/Makefile.am                               |    3
> >  ndctl/builtin.h                                 |    2
> >  ndctl/dimm.c                                    |   94 +++++-
> >  ndctl/lib/Makefile.am                           |    8
> >  ndctl/lib/dimm.c                                |   39 ++
> >  ndctl/lib/keys.c                                |  390 
> > +++++++++++++++++++++++
> >  ndctl/lib/libndctl.sym                          |    4
> >  ndctl/libndctl.h                                |   35 ++
> >  ndctl/ndctl.c                                   |    2
> >  14 files changed, 669 insertions(+), 13 deletions(-)
> >  create mode 100644 Documentation/ndctl/ndctl-enable-passphrase.txt
> >  create mode 100644 Documentation/ndctl/ndctl-update-passphrase.txt
> >  create mode 100644 ndctl/lib/keys.c
> > 
> > diff --git a/Documentation/ndctl/Makefile.am 
> > b/Documentation/ndctl/Makefile.am
> > index a30b139b..7ad6666b 100644
> > --- a/Documentation/ndctl/Makefile.am
> > +++ b/Documentation/ndctl/Makefile.am
> > @@ -47,7 +47,9 @@ man1_MANS = \
> >         ndctl-inject-smart.1 \
> >         ndctl-update-firmware.1 \
> >         ndctl-list.1 \
> > -       ndctl-monitor.1
> > +       ndctl-monitor.1 \
> > +       ndctl-enable-passphrase.1 \
> > +       ndctl-update-passphrase.1
> > 
> >  CLEANFILES = $(man1_MANS)
> > 
> > diff --git a/Documentation/ndctl/ndctl-enable-passphrase.txt 
> > b/Documentation/ndctl/ndctl-enable-passphrase.txt
> > new file mode 100644
> > index 00000000..c14a206c
> > --- /dev/null
> > +++ b/Documentation/ndctl/ndctl-enable-passphrase.txt
> > @@ -0,0 +1,42 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +ndctl-enable-passphrase(1)
> > +==========================
> > +
> > +NAME
> > +----
> > +ndctl-enable-passphrase - enable the security passphrase for a NVDIMM
> 
> *an NVDIMM
> 
> > +
> > +SYNOPSIS
> > +--------
> > +[verse]
> > +'ndctl enable-passphrase' <dimm> [<options>]
> 
> Is this true, there are no other required options besides the nmem
> device? No support for more than one nmem at a time?
> 
> > +
> > +DESCRIPTION
> > +-----------
> > +Provide a command to enable the security passphrase for the NVDIMM.
> 
> No need to say "Provide a command" that's assumed for a man page named
> after a binary.
> 
> So I'd say "Enable the security passphrase for one or more NVDIMMs.
> 
> > +It is expected that the master key has already been loaded into the user
> 
> Without listing the key-id as a required parameter it's not clear what
> the usage should be.
> 
> > +key ring. The encrypted key blobs will be created in /etc/nvdimm directory
> 
> Is this stale, should be /etc/ndctl/keys, right? Given the directory
> is changeable by the build system this source file should be built
> with the key directory as a variable.
> 
> > +with the file name of "nvdimm-<hostname>-<dimm unique id>.blob".
> 
> That's quite a bit to type out? Is there a command to discover this
> file name, or can we provide a short-hand?

I also noticed the actual file created was of the format:

  "nvdimm-<dimm unique id>-<hostname>.blob"

One of them should be made consistent with the other..

> 
> > +
> > +The command will fail if the nvdimm key is already in the user key ring 
> > and/or
> > +the key blob already resides in /etc/nvdimm.
> 
> I feel like this is missing a create-passphrase step, and/or that
> there needs to be an example in the man page. The man page should show
> sohow to create the pre-requisite material, or reference another
> command that will handle the details. I don't think the user interface
> should ever expose "nvdimm-<hostname>-<dimm unique id>.blob" as
> something the user needs to type... if at all possible. Maybe a global
> "set-kek" command to write out the key-encryption-key to a
> configuration file that enable-passphrase can consult by default
> rather than require it to be passed to every enable-passphrase
> invocation?
> 
> > Do not touch the /etc/nvdimm
> > +directory and let ndctl manage the keys, unless you know what you are 
> > doing.
> 
> I think the "unless you know what you are doing." sentiment goes
> without saying for a man page. If anything I'd ship a README file in
> /etc/ndctl/keys if you're worried about manual edits to that
> directory.
> 
> > +
> > +OPTIONS
> > +-------
> > +<dimm>::
> > +include::xable-dimm-options.txt[]
> > +
> > +-m::
> > +--master=::
> > +       Key name for the master key used to seal the NVDIMM security keys.
> > +       The format would be <key_type>:<master_key_name>
> > +       i.e.: trusted:master-nvdimm
> 
> "master" is ambiguous when we have master passphrases and master keys.
> Let's call it the KEK (key-encryption-key) and reserve "master" for
> "master passphrase".
> 
> > +-p::
> > +--key-path=::
> > +       Path to where key related files resides. This parameter is optional
> > +       and the default is set to /etc/ndctl/keys.
> 
> Is this flexibility needed? Seems like something that can be omitted
> unless/until a need arises.
> 
> > +
> > +include::../copyright.txt[]
> > diff --git a/Documentation/ndctl/ndctl-update-passphrase.txt 
> > b/Documentation/ndctl/ndctl-update-passphrase.txt
> > new file mode 100644
> > index 00000000..dd6e4e4e
> > --- /dev/null
> > +++ b/Documentation/ndctl/ndctl-update-passphrase.txt
> > @@ -0,0 +1,38 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +ndctl-update-passphrase(1)
> > +==========================
> > +
> > +NAME
> > +----
> > +ndctl-update-passphrase - update the security passphrase for a NVDIMM
> 
> *an NVDIMM
> 
> > +
> > +SYNOPSIS
> > +--------
> > +[verse]
> > +'ndctl update-passphrase' <dimm> [<options>]
> 
> Same comment about required options.
> 
> > +
> > +DESCRIPTION
> > +-----------
> > +Provide a command to update the security key for NVDIMM.
> 
> Same comment about "Provide a command"
> 
> > +It is expected that the current and the new (if new master key is desired)
> > +master key has already been loaded into the user key ring. The new 
> > encrypted
> > +key blobs will be created in /etc/nvdimm directory
> > +with the file name of "nvdimm-<hostname>-<dimm unique id>.blob".
> > +
> > +OPTIONS
> > +-------
> > +<dimm>::
> > +include::xable-dimm-options.txt[]
> > +
> > +-m::
> > +--master::
> > +       New key name for the master key to seal the new nvdimm key, or the
> > +       existing master key name. i.e trusted:master-key.
> > +
> > +-p::
> > +--key-path=::
> > +       Path to where key related files resides. This parameter is optional
> > +       and the default is set to /etc/ndctl/keys.
> 
> Same comment about an example and the need for key-path.
> 
> > +
> > +include::../copyright.txt[]
> > diff --git a/configure.ac b/configure.ac
> > index aa07ec7b..22efc871 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -154,6 +154,7 @@ fi
> >  AC_SUBST([systemd_unitdir])
> >  AM_CONDITIONAL([ENABLE_SYSTEMD_UNITS], [test "x$with_systemd" = "xyes"])
> > 
> > +
> >  ndctl_monitorconfdir=${sysconfdir}/ndctl
> >  ndctl_monitorconf=monitor.conf
> >  AC_SUBST([ndctl_monitorconfdir])
> > @@ -161,6 +162,24 @@ AC_SUBST([ndctl_monitorconf])
> >  AC_DEFINE_UNQUOTED(NDCTL_CONF_FILE, 
> > ["$ndctl_monitorconfdir/$ndctl_monitorconf"],
> >         [default ndctl monitor conf path])
> > 
> > +AC_ARG_WITH([keyutils],
> > +           AS_HELP_STRING([--with-keyutils],
> > +                       [Enable keyutils functionality (security).  
> > @<:@default=yes@:>@]), [], [with_keyutils=yes])
> > +
> > +if test "x$with_keyutils" = "xyes"; then
> > +       AC_CHECK_HEADERS([keyutils.h],,[
> > +               AC_MSG_ERROR([keyutils.h not found, consider installing
> > +                             keyutils-libs-devel.])
> > +               ])
> > +fi
> > +AS_IF([test "x$with_keyutils" = "xyes"],
> > +       [AC_DEFINE([ENABLE_KEYUTILS], [1], [Enable keyutils support])])
> > +AM_CONDITIONAL([ENABLE_KEYUTILS], [test "x$with_keyutils" = "xyes"])
> > +ndctl_keysdir=${sysconfdir}/ndctl/keys
> > +AC_SUBST([ndctl_keysdir])
> > +AC_DEFINE_UNQUOTED(NDCTL_KEYS_DIR, ["$ndctl_keysdir"],
> > +       [default ndctl keys path])
> 
> My bad, apparently AC_DEFINE_UNQUOTED falls over if $ndctl_keysdir is
> made up of components that need further expansion. Instead add
> NDCTL_KEYS_DIR to the new autogenerated ndctl/config.h file. See this
> pending patch where I killed off AC_DEFINE_UNQUOTED usage:
> https://patchwork.kernel.org/patch/10763963/
> 
> > +
> >  my_CFLAGS="\
> >  -Wall \
> >  -Wchar-subscripts \
> > diff --git a/ndctl.spec.in b/ndctl.spec.in
> > index 26396d4a..66466db6 100644
> > --- a/ndctl.spec.in
> > +++ b/ndctl.spec.in
> > @@ -21,6 +21,7 @@ BuildRequires:        pkgconfig(uuid)
> >  BuildRequires: pkgconfig(json-c)
> >  BuildRequires: pkgconfig(bash-completion)
> >  BuildRequires: pkgconfig(systemd)
> > +BuildRequires: keyutils-libs-devel
> > 
> >  %description
> >  Utility library for managing the "libnvdimm" subsystem.  The "libnvdimm"
> > @@ -119,6 +120,7 @@ make check
> >  %{bashcompdir}/
> >  %{_sysconfdir}/ndctl/monitor.conf
> >  %{_unitdir}/ndctl-monitor.service
> > +%{_sysconfdir}/ndctl/keys/
> > 
> >  %files -n daxctl
> >  %defattr(-,root,root)
> > diff --git a/ndctl/Makefile.am b/ndctl/Makefile.am
> > index ff01e068..120941a4 100644
> > --- a/ndctl/Makefile.am
> > +++ b/ndctl/Makefile.am
> > @@ -30,7 +30,8 @@ ndctl_LDADD =\
> >         ../libutil.a \
> >         $(UUID_LIBS) \
> >         $(KMOD_LIBS) \
> > -       $(JSON_LIBS)
> > +       $(JSON_LIBS) \
> > +       -lkeyutils
> 
> This should be conditional on whether ndctl was built with keyutils support.
> 
> ...reading ahead in the patch I don't think ndctl actually has a
> direct dependency on keyutils, right? It's abstracted behind the
> libndctl routines, so do we need this?
> 
> [..]
> > diff --git a/ndctl/lib/dimm.c b/ndctl/lib/dimm.c
> > index e03135d9..b64c9568 100644
> > --- a/ndctl/lib/dimm.c
> > +++ b/ndctl/lib/dimm.c
> > @@ -624,3 +624,42 @@ NDCTL_EXPORT int ndctl_dimm_get_security(struct 
> > ndctl_dimm *dimm,
> > 
> >         return 0;
> >  }
> > +
> > +NDCTL_EXPORT bool ndctl_dimm_security_supported(struct ndctl_dimm *dimm)
> > +{
> > +       enum nd_security_state state;
> > +       int rc;
> > +
> > +       rc = ndctl_dimm_get_security(dimm, &state);
> > +       if (rc < 0)
> > +               return false;
> > +
> > +       if (state == ND_SECURITY_UNSUPPORTED)
> > +               return false;
> > +
> > +       return true;
> > +}
> 
> I think the need for this goes away when ndctl_dimm_get_security()
> returns the state directly.
> 
> [..]
> > diff --git a/ndctl/ndctl.c b/ndctl/ndctl.c
> > index b01594e0..9d109b34 100644
> > --- a/ndctl/ndctl.c
> > +++ b/ndctl/ndctl.c
> > @@ -88,6 +88,8 @@ static struct cmd_struct commands[] = {
> >         { "inject-smart", { cmd_inject_smart } },
> >         { "wait-scrub", { cmd_wait_scrub } },
> >         { "start-scrub", { cmd_start_scrub } },
> > +       { "enable-passphrase", { cmd_passphrase_setup } },
> 
> Maybe call the command setup-passphrase. All the other enable commands
> are just toggling dynamic state, this one is creating persistent
> key-material.
> 
> > +       { "update-passphrase", { cmd_passphrase_update } },
> >         { "list", { cmd_list } },
> >         { "monitor", { cmd_monitor } },
> >         { "help", { cmd_help } },
> > 

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