grub2/0016-grub-install-support-embedding-x509-certificates.patch

From a0e17ba00ac128759d40e2bfc751716f45542ac0 Mon Sep 17 00:00:00 2001
From: Alastair D'Silva <alastair@d-silva.org>
Date: Mon, 6 Jul 2020 13:33:04 +1000
Subject: [PATCH 16/23] 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 <alastair@d-silva.org>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
 grub-core/commands/pgp.c    |  2 +-
 include/grub/kernel.h       |  3 ++-
 include/grub/util/install.h |  7 +++++--
 util/grub-install-common.c  | 22 +++++++++++++++++++-
 util/grub-mkimage.c         | 15 ++++++++++++--
 util/mkimage.c              | 41 ++++++++++++++++++++++++++++++++++---
 6 files changed, 80 insertions(+), 10 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/include/grub/kernel.h b/include/grub/kernel.h
index abbca5ea3..d3aafc884 100644
--- a/include/grub/kernel.h
+++ b/include/grub/kernel.h
@@ -28,7 +28,8 @@ enum
   OBJ_TYPE_MEMDISK,
   OBJ_TYPE_CONFIG,
   OBJ_TYPE_PREFIX,
-  OBJ_TYPE_PUBKEY,
+  OBJ_TYPE_GPG_PUBKEY,
+  OBJ_TYPE_X509_PUBKEY,
   OBJ_TYPE_DTB,
   OBJ_TYPE_DISABLE_SHIM_LOCK
 };
diff --git a/include/grub/util/install.h b/include/grub/util/install.h
index 0b2e8a06d..c241a2a40 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},                                                                 \
@@ -189,8 +191,9 @@ 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,
diff --git a/util/grub-install-common.c b/util/grub-install-common.c
index 954df20eb..44296afa0 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++ = '\'';
@@ -683,7 +702,8 @@ 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 d01eaeb84..7d61ef3ea 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,
diff --git a/util/mkimage.c b/util/mkimage.c
index d2cb33883..5a8021a21 100644
--- a/util/mkimage.c
+++ b/util/mkimage.c
@@ -866,8 +866,10 @@ init_pe_section(const struct grub_install_image_target_desc *image_target,
 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,
+			     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, grub_compression_t comp,
 			     const char *dtb_path, const char *sbat_path, 
@@ -913,6 +915,19 @@ 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 +1049,7 @@ 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 +1058,26 @@ 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;
-- 
2.31.1