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>

diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c
index a8502d90711153adf6c09294ca9c1a049ba8d69f..ee299fd0ea65b433765803d46e00d255031b3a91 100644 (file)
--- 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 3d8f3e1a475e2d31afeb9c20ec52a348e073e3a7..ea049143368e7c3ee41d3906e0dd16aa09838a6b 100644 (file)
--- 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