From d3a5e812c5da935eba5bb283792cf820ffc85ac6 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg59@google.com>
Date: Thu, 29 Nov 2018 11:28:08 -0800
Subject: [PATCH] verifiers: Verify commands executed by grub

Pass all commands executed by GRUB to the verifiers layer. Most verifiers will
ignore this, but some (such as the TPM verifier) want to be able to measure and
log each command executed in order to ensure that the boot state is as expected.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/script/execute.c | 27 ++++++++++++++++++++++++---
 include/grub/verify.h      |  1 +
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c
index a8502d907..ee299fd0e 100644
--- a/grub-core/script/execute.c
+++ b/grub-core/script/execute.c
@@ -27,6 +27,7 @@
 #include <grub/normal.h>
 #include <grub/extcmd.h>
 #include <grub/i18n.h>
+#include <grub/verify.h>
 
 /* Max digits for a char is 3 (0xFF is 255), similarly for an int it
    is sizeof (int) * 3, and one extra for a possible -ve sign.  */
@@ -929,8 +930,9 @@ grub_script_execute_cmdline (struct grub_script_cmd *cmd)
   grub_err_t ret = 0;
   grub_script_function_t func = 0;
   char errnobuf[18];
-  char *cmdname;
-  int argc;
+  char *cmdname, *cmdstring;
+  int argc, offset = 0, cmdlen = 0;
+  unsigned int i;
   char **args;
   int invert;
   struct grub_script_argv argv = { 0, 0, 0 };
@@ -939,6 +941,26 @@ grub_script_execute_cmdline (struct grub_script_cmd *cmd)
   if (grub_script_arglist_to_argv (cmdline->arglist, &argv) || ! argv.args[0])
     return grub_errno;
 
+  for (i = 0; i < argv.argc; i++)
+    {
+      cmdlen += grub_strlen (argv.args[i]) + 1;
+    }
+
+  cmdstring = grub_malloc (cmdlen);
+  if (!cmdstring)
+    {
+      return grub_error (GRUB_ERR_OUT_OF_MEMORY,
+			 N_("cannot allocate command buffer"));
+    }
+
+  for (i = 0; i < argv.argc; i++)
+    {
+      offset += grub_snprintf (cmdstring + offset, cmdlen - offset, "%s ",
+			       argv.args[i]);
+    }
+  cmdstring[cmdlen - 1] = '\0';
+  grub_verify_string (cmdstring, GRUB_VERIFY_COMMAND);
+  grub_free (cmdstring);
   invert = 0;
   argc = argv.argc - 1;
   args = argv.args + 1;
@@ -1163,4 +1185,3 @@ grub_script_execute (struct grub_script *script)
 
   return grub_script_execute_cmd (script->cmd);
 }
-
diff --git a/include/grub/verify.h b/include/grub/verify.h
index 3d8f3e1a4..ea0491433 100644
--- a/include/grub/verify.h
+++ b/include/grub/verify.h
@@ -34,6 +34,7 @@ enum grub_verify_string_type
   {
     GRUB_VERIFY_KERNEL_CMDLINE,
     GRUB_VERIFY_MODULE_CMDLINE,
+    GRUB_VERIFY_COMMAND,
   };
 
 struct grub_file_verifier