[PATCH v4 10/11] mkeficapsule: Add support for generating empty capsules
Sughosh Ganu
sughosh.ganu at linaro.org
Fri Feb 11 14:27:03 CET 2022
On Thu, 10 Feb 2022 at 06:57, AKASHI Takahiro
<takahiro.akashi at linaro.org> wrote:
>
> On Wed, Feb 09, 2022 at 12:05:06PM +0900, AKASHI Takahiro wrote:
> > Hi Sughosh,
> >
> > On Mon, Feb 07, 2022 at 11:50:00PM +0530, Sughosh Ganu wrote:
> > > The Dependable Boot specification describes the structure of the
> >
> > What is this specification? Please specify the link to the doc.
> >
> > > firmware accept and revert capsules. These are empty capsules which
> > > are used for signalling the acceptance or rejection of the updated
> > > firmware by the OS. Add support for generating these empty capsules.
> > >
> > > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> > > ---
> > >
> > > Changes since V3:
> > > * Add related documentation for empty capsules in the mkeficapsule man
> > > page.
> > > * Add separate usage for empty capsules, with corresponding valid
> > > options.
> > > * Use ternary operators where possible.
> > > * Put a exclusivity check for the empty capsule options.
> > >
> > > doc/mkeficapsule.1 | 23 +++++++-
> > > tools/eficapsule.h | 8 +++
> > > tools/mkeficapsule.c | 131 ++++++++++++++++++++++++++++++++++++-------
> > > 3 files changed, 139 insertions(+), 23 deletions(-)
> > >
> > > diff --git a/doc/mkeficapsule.1 b/doc/mkeficapsule.1
> > > index 8babb27ee8..75fc15906a 100644
> > > --- a/doc/mkeficapsule.1
> > > +++ b/doc/mkeficapsule.1
> > > @@ -8,7 +8,7 @@ mkeficapsule \- Generate EFI capsule file for U-Boot
> > >
> > > .SH SYNOPSIS
> > > .B mkeficapsule
> > > -.RI [ options "] " image-blob " " capsule-file
> > > +.RI [ options ] " " [ image-blob ] " " capsule-file
> >
> > With this formatting, "capsule-file" will get italic.
>
> oops, I meant to say "roman."
>
> > => .RI [ options "] [" image-blob "] " capsule-file
> >
> > Right?
> >
> > Furthermore, I think we can describe the command syntax of the two
> > different cases (normal or empty capsule) more specifically.
> >
> > >
> > > .SH "DESCRIPTION"
> > > .B mkeficapsule
> > > @@ -23,8 +23,13 @@ Optionally, a capsule file can be signed with a given private key.
> > > In this case, the update will be authenticated by verifying the signature
> > > before applying.
> > >
> > > +Additionally, an empty capsule file can be generated for acceptance or
> > > +rejection of firmware images by a governing component like an Operating
> > > +System. The empty capsules do not require an image-blob input file.
> > > +
> > > +
> > > .B mkeficapsule
> > > -takes any type of image files, including:
> > > +takes any type of image files when generating non empty capsules, including:
> > > .TP
> > > .I raw image
> > > format is a single binary blob of any type of firmware.
> > > @@ -43,7 +48,7 @@ specify a guid for the FMP driver.
> > > .SH "OPTIONS"
> > > One of
> > > .BR --fit ", " --raw " or " --guid
> > > -option must be specified.
> > > +option must be specified for non empty capsules.
> > >
> > > .TP
> > > .BR -f ", " --fit
> > > @@ -69,6 +74,18 @@ Specify an image index
> > > .BI "-I\fR,\fB --instance " instance
> > > Specify a hardware instance
> > >
> > > +.PP
> > > +For generation of firmware accept empty capsule
> > > +.BR --guid
> > > +is mandatory
> >
> > I don't still understand why we need GUID for accept empty capsule.
> > We should have only one choice, whether all the new firmware be
> > permanently applied or completely reverted.
> >
> > That's A/B update, isn't it?
> >
> > > +.TP
> > > +.BI "-A\fR,\fB --fw-accept "
> > > +Generate a firmware acceptance empty capsule
> > > +
> > > +.TP
> > > +.BI "-R\fR,\fB --fw-revert "
> > > +Generate a firmware revert empty capsule
> > > +
> > > .TP
> > > .BR -h ", " --help
> > > Print a help message
> > > diff --git a/tools/eficapsule.h b/tools/eficapsule.h
> > > index 8c1560bb06..6001952bdc 100644
> > > --- a/tools/eficapsule.h
> > > +++ b/tools/eficapsule.h
> > > @@ -50,6 +50,14 @@ typedef struct {
> > > EFI_GUID(0x4aafd29d, 0x68df, 0x49ee, 0x8a, 0xa9, \
> > > 0x34, 0x7d, 0x37, 0x56, 0x65, 0xa7)
> > >
> > > +#define FW_ACCEPT_OS_GUID \
> > > + EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \
> > > + 0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8)
> > > +
> > > +#define FW_REVERT_OS_GUID \
> > > + EFI_GUID(0xacd58b4b, 0xc0e8, 0x475f, 0x99, 0xb5, \
> > > + 0x6b, 0x3f, 0x7e, 0x07, 0xaa, 0xf0)
> > > +
> > > /* flags */
> > > #define CAPSULE_FLAGS_PERSIST_ACROSS_RESET 0x00010000
> > >
> > > diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c
> > > index 161affdd15..e5dbec3a92 100644
> > > --- a/tools/mkeficapsule.c
> > > +++ b/tools/mkeficapsule.c
> > > @@ -29,6 +29,7 @@
> > > #include "eficapsule.h"
> > >
> > > static const char *tool_name = "mkeficapsule";
> > > +unsigned char accept_fw_capsule, revert_fw_capsule, empty_capsule;
> >
> > Bool? but those variables are redundant.
> >
> > As Ilias suggested, introducing a new enum type here can
> > simplify the code in the following code.
> > enum {
> > CAPSULE_NORMAL_BLOB = 0,
> > CAPSULE_ACCEPT,
> > CAPSULE_REVERT,
> > } capsule_type;
> >
> >
> > >
> > > efi_guid_t efi_guid_fm_capsule = EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID;
> > > efi_guid_t efi_guid_image_type_uboot_fit =
> > > @@ -38,9 +39,9 @@ efi_guid_t efi_guid_image_type_uboot_raw =
> > > efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID;
> > >
> > > #ifdef CONFIG_TOOLS_LIBCRYPTO
> >
> > Please rebase your patch to my v10 or later.
> > I have already removed the dependency on openssl library.
> >
> > > -static const char *opts_short = "frg:i:I:v:p:c:m:dh";
> > > +static const char *opts_short = "frg:i:I:v:p:c:m:dhAR";
> > > #else
> > > -static const char *opts_short = "frg:i:I:v:h";
> > > +static const char *opts_short = "frg:i:I:v:hAR";
> > > #endif
> > >
> > > static struct option options[] = {
> > > @@ -55,28 +56,50 @@ static struct option options[] = {
> > > {"monotonic-count", required_argument, NULL, 'm'},
> > > {"dump-sig", no_argument, NULL, 'd'},
> > > #endif
> > > + {"fw-accept", no_argument, NULL, 'A'},
> > > + {"fw-revert", no_argument, NULL, 'R'},
> > > {"help", no_argument, NULL, 'h'},
> > > {NULL, 0, NULL, 0},
> > > };
> > >
> > > static void print_usage(void)
> > > {
> > > - fprintf(stderr, "Usage: %s [options] <image blob> <output file>\n"
> > > - "Options:\n"
> > > -
> > > - "\t-f, --fit FIT image type\n"
> > > - "\t-r, --raw raw image type\n"
> > > - "\t-g, --guid <guid string> guid for image blob type\n"
> > > - "\t-i, --index <index> update image index\n"
> > > - "\t-I, --instance <instance> update hardware instance\n"
> > > + if (empty_capsule) {
> > > + if (accept_fw_capsule) {
> > > + fprintf(stderr, "Usage: %s [options] <output file>\n",
> > > + tool_name);
> > > + fprintf(stderr, "Options:\n"
> > > + "\t-A, --fw-accept firmware accept capsule\n"
> > > + "\t-g, --guid <guid string> guid for image blob type\n"
> >
> > While I doubt the necessity of "--guid,"
> > why not accept "-f" or "-r" as a guid of image blob type?
> > (It seems that your actual code does.)
> >
> > > + "\t-h, --help print a help message\n"
> > > + );
> > > + } else {
> > > + fprintf(stderr, "Usage: %s [options] <output file>\n",
> > > + tool_name);
> > > + fprintf(stderr, "Options:\n"
> > > + "\t-R, --fw-revert firmware revert capsule\n"
> > > + "\t-h, --help print a help message\n"
> > > + );
> > > + }
> > > + } else {
> > > + fprintf(stderr, "Usage: %s [options] <image blob> <output file>\n",
> > > + tool_name);
> > > + fprintf(stderr, "Options:\n"
> > > + "\t-f, --fit FIT image type\n"
> > > + "\t-r, --raw raw image type\n"
> > > + "\t-g, --guid <guid string> guid for image blob type\n"
> > > + "\t-i, --index <index> update image index\n"
> > > + "\t-I, --instance <instance> update hardware instance\n"
> > > #ifdef CONFIG_TOOLS_LIBCRYPTO
> > > - "\t-p, --private-key <privkey file> private key file\n"
> > > - "\t-c, --certificate <cert file> signer's certificate file\n"
> > > - "\t-m, --monotonic-count <count> monotonic count\n"
> > > - "\t-d, --dump_sig dump signature (*.p7)\n"
> > > + "\t-p, --private-key <privkey file> private key file\n"
> > > + "\t-c, --certificate <cert file> signer's certificate file\n"
> > > + "\t-m, --monotonic-count <count> monotonic count\n"
> > > + "\t-d, --dump_sig dump signature (*.p7)\n"
> > > #endif
> > > - "\t-h, --help print a help message\n",
> > > - tool_name);
> > > + "\t-A, --fw-accept firmware accept capsule\n"
> > > + "\t-R, --fw-revert firmware revert capsule\n"
> > > + "\t-h, --help print a help message\n");
> > > + }
> > > }
> > >
> > > /**
> > > @@ -598,6 +621,50 @@ void convert_uuid_to_guid(unsigned char *buf)
> > > buf[7] = c;
> > > }
> > >
> > > +static int create_empty_capsule(char *path, efi_guid_t *guid, bool fw_accept)
> > > +{
> > > + struct efi_capsule_header header;
> > > + FILE *f = NULL;
> > > + int ret = -1;
> > > + efi_guid_t fw_accept_guid = FW_ACCEPT_OS_GUID;
> > > + efi_guid_t fw_revert_guid = FW_REVERT_OS_GUID;
> > > + efi_guid_t payload, capsule_guid;
> > > +
> > > + f = fopen(path, "w");
> > > + if (!f) {
> > > + fprintf(stderr, "cannot open %s\n", path);
> > > + goto err;
> > > + }
> > > +
> > > + capsule_guid = fw_accept ? fw_accept_guid : fw_revert_guid;
> > > +
> > > + memcpy(&header.capsule_guid, &capsule_guid, sizeof(efi_guid_t));
> > > + header.header_size = sizeof(header);
> > > + header.flags = 0;
> > > +
> > > + header.capsule_image_size = fw_accept ?
> > > + sizeof(header) + sizeof(efi_guid_t) : sizeof(header);
> > > +
> > > + if (write_capsule_file(f, &header, sizeof(header),
> > > + "Capsule header"))
> > > + goto err;
> > > +
> > > + if (fw_accept) {
> > > + memcpy(&payload, guid, sizeof(efi_guid_t));
> > > + if (write_capsule_file(f, &payload, sizeof(payload),
> > > + "FW Accept Capsule Payload"))
> > > + goto err;
> > > + }
> > > +
> > > + ret = 0;
> > > +
> > > +err:
> > > + if (f)
> > > + fclose(f);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > /**
> > > * main - main entry function of mkeficapsule
> > > * @argc: Number of arguments
> > > @@ -625,6 +692,8 @@ int main(int argc, char **argv)
> > > mcount = 0;
> > > privkey_file = NULL;
> > > cert_file = NULL;
> > > + accept_fw_capsule = 0;
> > > + revert_fw_capsule = 0;
> > > dump_sig = 0;
> > > for (;;) {
> > > c = getopt_long(argc, argv, opts_short, options, &idx);
> > > @@ -691,22 +760,44 @@ int main(int argc, char **argv)
> > > dump_sig = 1;
> > > break;
> > > #endif /* CONFIG_TOOLS_LIBCRYPTO */
> > > + case 'A':
> > > + accept_fw_capsule = 1;
> > > + break;
> > > + case 'R':
> > > + revert_fw_capsule = 1;
> > > + break;
> > > case 'h':
> > > print_usage();
> > > exit(EXIT_SUCCESS);
> > > }
> > > }
> > >
> > > + if (accept_fw_capsule && revert_fw_capsule) {
> > > + fprintf(stderr,
> > > + "Select either of Accept or Revert capsule generation\n");
> > > + exit(EXIT_FAILURE);
> > > + }
> > > +
> > > + empty_capsule = (accept_fw_capsule || revert_fw_capsule);
> > > +
> > > /* check necessary parameters */
> > > - if ((argc != optind + 2) || !guid ||
> > > - ((privkey_file && !cert_file) ||
> > > + if ((!empty_capsule && argc != optind + 2) ||
> > > + (empty_capsule && argc != optind + 1) ||
> > > + (!revert_fw_capsule && !guid) || ((privkey_file && !cert_file) ||
> > > (!privkey_file && cert_file))) {
> >
> > Well, the error condition looks complicated due to mixing two cases
> > and can be hard to maintain in the future. How about
> > if (!empty_capsule &&
> > ((argc != optind + 2) || !guid ||
> > ((privkey_file && !cert_file) ||
> > (!privkey_file && cert_file))) ||
> > empty_capsule &&
> > ((argc != optind + 1) ||
> > (accept_fw_capsule && revert_fw_capsule) ||
> > (accept_fw_capsule && !guid)) # arguable as mentioned above
> > (revert_fw_capsule && guid))
> > ...
>
> I've got one concern here; Can we sign an empty capsule file?
> I think we should.
> If so, the help message (by print_usage()) doesn't reflect it.
We do have plans to sign the empty capsule, although it is not being
added currently. I will keep this on my Todo list. Hope that is fine.
Thanks.
-sughosh
>
> -Takahiro Akashi
>
> >
> > > print_usage();
> > > exit(EXIT_FAILURE);
> > > }
> > >
> > > - if (create_fwbin(argv[argc - 1], argv[argc - 2], guid, index, instance,
> > > - mcount, privkey_file, cert_file) < 0) {
> > > + if (empty_capsule) {
> > > + if (create_empty_capsule(argv[argc - 1], guid,
> > > + accept_fw_capsule ? 1 : 0) < 0) {
> >
> > The third argument can be simplified to "accept_fw_capsule".
> >
> > -Takahiro Akashi
> >
> > > + fprintf(stderr, "Creating empty capsule failed\n");
> > > + exit(EXIT_FAILURE);
> > > + }
> > > + } else if (create_fwbin(argv[argc - 1], argv[argc - 2], guid,
> > > + index, instance, mcount, privkey_file,
> > > + cert_file) < 0) {
> > > fprintf(stderr, "Creating firmware capsule failed\n");
> > > exit(EXIT_FAILURE);
> > > }
> > > --
> > > 2.17.1
> > >
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