From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Alastair D'Silva Date: Mon, 6 Jul 2020 13:33:04 +1000 Subject: [PATCH] grub-install: support embedding x509 certificates To support verification of appended signatures, we need a way to embed the necessary public keys. Existing appended signature schemes in the Linux kernel use X.509 certificates, so allow certificates to be embedded in the grub core image in the same way as PGP keys. Signed-off-by: Alastair D'Silva Signed-off-by: Daniel Axtens --- grub-core/commands/pgp.c | 2 +- util/grub-install-common.c | 23 ++++++++++++++++++++++- util/grub-mkimage.c | 15 +++++++++++++-- util/mkimage.c | 38 ++++++++++++++++++++++++++++++++++++-- include/grub/kernel.h | 4 +++- include/grub/util/install.h | 7 +++++-- 6 files changed, 80 insertions(+), 9 deletions(-) diff --git a/grub-core/commands/pgp.c b/grub-core/commands/pgp.c index 355a43844..b81ac0ae4 100644 --- a/grub-core/commands/pgp.c +++ b/grub-core/commands/pgp.c @@ -944,7 +944,7 @@ GRUB_MOD_INIT(pgp) grub_memset (&pseudo_file, 0, sizeof (pseudo_file)); /* Not an ELF module, skip. */ - if (header->type != OBJ_TYPE_PUBKEY) + if (header->type != OBJ_TYPE_GPG_PUBKEY) continue; pseudo_file.fs = &pseudo_fs; diff --git a/util/grub-install-common.c b/util/grub-install-common.c index a74fee16e..c603f5b30 100644 --- a/util/grub-install-common.c +++ b/util/grub-install-common.c @@ -460,6 +460,8 @@ static char **pubkeys; static size_t npubkeys; static char *sbat; static int disable_shim_lock; +static char **x509keys; +static size_t nx509keys; static grub_compression_t compression; static size_t appsig_size; @@ -501,6 +503,12 @@ grub_install_parse (int key, char *arg) case GRUB_INSTALL_OPTIONS_DISABLE_SHIM_LOCK: disable_shim_lock = 1; return 1; + case 'x': + x509keys = xrealloc (x509keys, + sizeof (x509keys[0]) + * (nx509keys + 1)); + x509keys[nx509keys++] = xstrdup (arg); + return 1; case GRUB_INSTALL_OPTIONS_VERBOSITY: verbosity++; @@ -627,6 +635,9 @@ grub_install_make_image_wrap_file (const char *dir, const char *prefix, for (pk = pubkeys; pk < pubkeys + npubkeys; pk++) slen += 20 + grub_strlen (*pk); + for (pk = x509keys; pk < x509keys + nx509keys; pk++) + slen += 10 + grub_strlen (*pk); + for (md = modules.entries; *md; md++) { slen += 10 + grub_strlen (*md); @@ -655,6 +666,14 @@ grub_install_make_image_wrap_file (const char *dir, const char *prefix, *p++ = ' '; } + for (pk = x509keys; pk < x509keys + nx509keys; pk++) + { + p = grub_stpcpy (p, "--x509 '"); + p = grub_stpcpy (p, *pk); + *p++ = '\''; + *p++ = ' '; + } + for (md = modules.entries; *md; md++) { *p++ = '\''; @@ -684,7 +703,9 @@ grub_install_make_image_wrap_file (const char *dir, const char *prefix, grub_install_generate_image (dir, prefix, fp, outname, modules.entries, memdisk_path, - pubkeys, npubkeys, config_path, tgt, + pubkeys, npubkeys, + x509keys, nx509keys, + config_path, tgt, note, appsig_size, compression, dtb, sbat, disable_shim_lock); while (dc--) diff --git a/util/grub-mkimage.c b/util/grub-mkimage.c index 8a5331054..e1f111278 100644 --- a/util/grub-mkimage.c +++ b/util/grub-mkimage.c @@ -75,7 +75,8 @@ static struct argp_option options[] = { /* TRANSLATORS: "embed" is a verb (command description). "*/ {"config", 'c', N_("FILE"), 0, N_("embed FILE as an early config"), 0}, /* TRANSLATORS: "embed" is a verb (command description). "*/ - {"pubkey", 'k', N_("FILE"), 0, N_("embed FILE as public key for signature checking"), 0}, + {"pubkey", 'k', N_("FILE"), 0, N_("embed FILE as public key for PGP signature checking"), 0}, + {"x509", 'x', N_("FILE"), 0, N_("embed FILE as an x509 certificate for appended signature checking"), 0}, /* TRANSLATORS: NOTE is a name of segment. */ {"note", 'n', 0, 0, N_("add NOTE segment for CHRP IEEE1275"), 0}, {"output", 'o', N_("FILE"), 0, N_("output a generated image to FILE [default=stdout]"), 0}, @@ -124,6 +125,8 @@ struct arguments char *dtb; char **pubkeys; size_t npubkeys; + char **x509keys; + size_t nx509keys; char *font; char *config; char *sbat; @@ -206,6 +209,13 @@ argp_parser (int key, char *arg, struct argp_state *state) arguments->pubkeys[arguments->npubkeys++] = xstrdup (arg); break; + case 'x': + arguments->x509keys = xrealloc (arguments->x509keys, + sizeof (arguments->x509keys[0]) + * (arguments->nx509keys + 1)); + arguments->x509keys[arguments->nx509keys++] = xstrdup (arg); + break; + case 'c': if (arguments->config) free (arguments->config); @@ -332,7 +342,8 @@ main (int argc, char *argv[]) grub_install_generate_image (arguments.dir, arguments.prefix, fp, arguments.output, arguments.modules, arguments.memdisk, arguments.pubkeys, - arguments.npubkeys, arguments.config, + arguments.npubkeys, arguments.x509keys, + arguments.nx509keys, arguments.config, arguments.image_target, arguments.note, arguments.appsig_size, arguments.comp, arguments.dtb, arguments.sbat, diff --git a/util/mkimage.c b/util/mkimage.c index bab122760..8319e8dfb 100644 --- a/util/mkimage.c +++ b/util/mkimage.c @@ -867,7 +867,8 @@ void grub_install_generate_image (const char *dir, const char *prefix, FILE *out, const char *outname, char *mods[], char *memdisk_path, char **pubkey_paths, - size_t npubkeys, char *config_path, + size_t npubkeys, char **x509key_paths, + size_t nx509keys, char *config_path, const struct grub_install_image_target_desc *image_target, int note, size_t appsig_size, grub_compression_t comp, const char *dtb_path, const char *sbat_path, @@ -913,6 +914,19 @@ grub_install_generate_image (const char *dir, const char *prefix, } } + { + size_t i; + for (i = 0; i < nx509keys; i++) + { + size_t curs; + curs = ALIGN_ADDR (grub_util_get_image_size (x509key_paths[i])); + grub_util_info ("the size of x509 public key %u is 0x%" + GRUB_HOST_PRIxLONG_LONG, + (unsigned) i, (unsigned long long) curs); + total_module_size += curs + sizeof (struct grub_module_header); + } + } + if (memdisk_path) { memdisk_size = ALIGN_UP(grub_util_get_image_size (memdisk_path), 512); @@ -1034,7 +1048,7 @@ grub_install_generate_image (const char *dir, const char *prefix, curs = grub_util_get_image_size (pubkey_paths[i]); header = (struct grub_module_header *) (kernel_img + offset); - header->type = grub_host_to_target32 (OBJ_TYPE_PUBKEY); + header->type = grub_host_to_target32 (OBJ_TYPE_GPG_PUBKEY); header->size = grub_host_to_target32 (curs + sizeof (*header)); offset += sizeof (*header); @@ -1043,6 +1057,26 @@ grub_install_generate_image (const char *dir, const char *prefix, } } + { + size_t i; + for (i = 0; i < nx509keys; i++) + { + size_t curs; + struct grub_module_header *header; + + curs = grub_util_get_image_size (x509key_paths[i]); + + header = (struct grub_module_header *) (kernel_img + offset); + header->type = grub_host_to_target32 (OBJ_TYPE_X509_PUBKEY); + header->size = grub_host_to_target32 (curs + sizeof (*header)); + offset += sizeof (*header); + + grub_util_load_image (x509key_paths[i], kernel_img + offset); + offset += ALIGN_ADDR (curs); + } + } + + if (memdisk_path) { struct grub_module_header *header; diff --git a/include/grub/kernel.h b/include/grub/kernel.h index 55849777e..98edc0863 100644 --- a/include/grub/kernel.h +++ b/include/grub/kernel.h @@ -30,7 +30,9 @@ enum OBJ_TYPE_PREFIX, OBJ_TYPE_PUBKEY, OBJ_TYPE_DTB, - OBJ_TYPE_DISABLE_SHIM_LOCK + OBJ_TYPE_DISABLE_SHIM_LOCK, + OBJ_TYPE_GPG_PUBKEY, + OBJ_TYPE_X509_PUBKEY, }; /* The module header. */ diff --git a/include/grub/util/install.h b/include/grub/util/install.h index cf4531e02..51f3b13ac 100644 --- a/include/grub/util/install.h +++ b/include/grub/util/install.h @@ -67,6 +67,8 @@ N_("SBAT metadata"), 0 }, \ { "disable-shim-lock", GRUB_INSTALL_OPTIONS_DISABLE_SHIM_LOCK, 0, 0, \ N_("disable shim_lock verifier"), 0 }, \ + { "x509key", 'x', N_("FILE"), 0, \ + N_("embed FILE as an x509 certificate for signature checking"), 0}, \ { "appended-signature-size", GRUB_INSTALL_OPTIONS_APPENDED_SIGNATURE_SIZE,\ "SIZE", 0, N_("Add a note segment reserving SIZE bytes for an appended signature"), \ 1}, \ @@ -188,8 +190,9 @@ void grub_install_generate_image (const char *dir, const char *prefix, FILE *out, const char *outname, char *mods[], - char *memdisk_path, char **pubkey_paths, - size_t npubkeys, + char *memdisk_path, + char **pubkey_paths, size_t npubkeys, + char **x509key_paths, size_t nx509keys, char *config_path, const struct grub_install_image_target_desc *image_target, int note, size_t appsig_size,