[PATCH v2 02/10] tpm2_key_protector: Add 'tpm2_dump_pcr' command

[Gary Lin]

The user may need to inspect the TPM 2.0 PCR values with the GRUB shell,
so the new 'tpm2_dump_pcr' command is added to print all PCRs of the
specified bank.

Signed-off-by: Gary Lin <glin@suse.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
---
 .../commands/tpm2_key_protector/module.c      | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/grub-core/commands/tpm2_key_protector/module.c 
b/grub-core/commands/tpm2_key_protector/module.c
index d5e530f77..0a5d81e4c 100644
--- a/grub-core/commands/tpm2_key_protector/module.c
+++ b/grub-core/commands/tpm2_key_protector/module.c
@@ -160,6 +160,8 @@ static grub_extcmd_t tpm2_protector_init_cmd;
 static grub_extcmd_t tpm2_protector_clear_cmd;
 static tpm2_protector_context_t tpm2_protector_ctx = {0};
 
+static grub_command_t tpm2_dump_pcr_cmd;
+
 static grub_err_t
 tpm2_protector_srk_read_file (const char *filepath, void **buffer, grub_size_t 
*buffer_size)
 {
@@ -1315,6 +1317,33 @@ static struct grub_key_protector tpm2_key_protector =
     .recover_key = tpm2_protector_recover_key
   };
 
+static grub_err_t
+tpm2_dump_pcr (grub_command_t cmd __attribute__((__unused__)),
+              int argc, char *argv[])
+{
+  TPM_ALG_ID_t pcr_bank;
+
+  if (argc == 0)
+    pcr_bank = TPM_ALG_SHA256;
+  else if (grub_strcmp (argv[0], "sha1") == 0)
+    pcr_bank = TPM_ALG_SHA1;
+  else if (grub_strcmp (argv[0], "sha256") == 0)
+    pcr_bank = TPM_ALG_SHA256;
+  else if (grub_strcmp (argv[0], "sha384") == 0)
+    pcr_bank = TPM_ALG_SHA384;
+  else if (grub_strcmp (argv[0], "sha512") == 0)
+    pcr_bank = TPM_ALG_SHA512;
+  else
+    {
+      grub_printf ("Unknown PCR bank\n");
+      return GRUB_ERR_BAD_ARGUMENT;
+    }
+
+  tpm2_protector_dump_pcr (pcr_bank);
+
+  return GRUB_ERR_NONE;
+}
+
 GRUB_MOD_INIT (tpm2_key_protector)
 {
   tpm2_protector_init_cmd =
@@ -1336,6 +1365,10 @@ GRUB_MOD_INIT (tpm2_key_protector)
                          N_("Clear the TPM2 key protector if previously 
initialized."),
                          NULL);
   grub_key_protector_register (&tpm2_key_protector);
+
+  tpm2_dump_pcr_cmd =
+    grub_register_command ("tpm2_dump_pcr", tpm2_dump_pcr, N_("Dump TPM2 
PCRs"),
+                          N_("Print all PCRs of the specified TPM 2.0 bank"));
 }
 
 GRUB_MOD_FINI (tpm2_key_protector)
@@ -1345,4 +1378,6 @@ GRUB_MOD_FINI (tpm2_key_protector)
   grub_key_protector_unregister (&tpm2_key_protector);
   grub_unregister_extcmd (tpm2_protector_clear_cmd);
   grub_unregister_extcmd (tpm2_protector_init_cmd);
+
+  grub_unregister_command (tpm2_dump_pcr_cmd);
 }
-- 
2.43.0