[PATCH 4/7] tss2: Implement grub_tcg2_cap_pcr() for ieee1275

[Gary Lin via Grub-devel <grub-devel@gnu.org>]

This commit implements grub_tcg2_cap_pcr() for ieee1275 with the
firmware function, 2hash-ext-log, to extend the target PCR with a
SEPARATOR event and record the event into the TPM event log.

To avoid duplicate code, ibmvtpm_2hash_ext_log() is moved to tcg2.c
and exported as a global function.

Signed-off-by: Gary Lin <glin@suse.com>
---
 grub-core/commands/ieee1275/ibmvtpm.c | 52 ++-------------------
 grub-core/lib/ieee1275/tcg2.c         | 66 +++++++++++++++++++++++++++
 include/grub/ieee1275/tpm.h           |  5 ++
 3 files changed, 74 insertions(+), 49 deletions(-)

diff --git a/grub-core/commands/ieee1275/ibmvtpm.c b/grub-core/commands/ieee1275/ibmvtpm.c
index 4958b04a9..d0ddc06b0 100644
--- a/grub-core/commands/ieee1275/ibmvtpm.c
+++ b/grub-core/commands/ieee1275/ibmvtpm.c
@@ -27,52 +27,6 @@
 #include <grub/mm.h>
 #include <grub/misc.h>
 
-static int
-ibmvtpm_2hash_ext_log (grub_uint8_t pcrindex,
-		       grub_uint32_t eventtype,
-		       const char *description,
-		       grub_size_t description_size,
-		       void *buf, grub_size_t size)
-{
-  struct tpm_2hash_ext_log
-  {
-    struct grub_ieee1275_common_hdr common;
-    grub_ieee1275_cell_t method;
-    grub_ieee1275_cell_t ihandle;
-    grub_ieee1275_cell_t size;
-    grub_ieee1275_cell_t buf;
-    grub_ieee1275_cell_t description_size;
-    grub_ieee1275_cell_t description;
-    grub_ieee1275_cell_t eventtype;
-    grub_ieee1275_cell_t pcrindex;
-    grub_ieee1275_cell_t catch_result;
-    grub_ieee1275_cell_t rc;
-  };
-  struct tpm_2hash_ext_log args;
-
-  INIT_IEEE1275_COMMON (&args.common, "call-method", 8, 2);
-  args.method = (grub_ieee1275_cell_t) "2hash-ext-log";
-  args.ihandle = grub_ieee1275_tpm_ihandle;
-  args.pcrindex = pcrindex;
-  args.eventtype = eventtype;
-  args.description = (grub_ieee1275_cell_t) description;
-  args.description_size = description_size;
-  args.buf = (grub_ieee1275_cell_t) buf;
-  args.size = (grub_ieee1275_cell_t) size;
-
-  if (IEEE1275_CALL_ENTRY_FN (&args) == -1)
-    return -1;
-
-  /*
-   * catch_result is set if firmware does not support 2hash-ext-log
-   * rc is GRUB_IEEE1275_CELL_FALSE (0) on failure
-   */
-  if ((args.catch_result) || args.rc == GRUB_IEEE1275_CELL_FALSE)
-    return -1;
-
-  return 0;
-}
-
 static grub_err_t
 tpm2_log_event (unsigned char *buf, grub_size_t size, grub_uint8_t pcr,
 		const char *description)
@@ -80,9 +34,9 @@ tpm2_log_event (unsigned char *buf, grub_size_t size, grub_uint8_t pcr,
   static int error_displayed = 0;
   int rc;
 
-  rc = ibmvtpm_2hash_ext_log (pcr, EV_IPL,
-			      description, grub_strlen(description) + 1,
-			      buf, size);
+  rc = grub_ieee1275_ibmvtpm_2hash_ext_log (pcr, EV_IPL,
+					    description, grub_strlen(description) + 1,
+					    buf, size);
   if (rc && !error_displayed)
     {
       error_displayed++;
diff --git a/grub-core/lib/ieee1275/tcg2.c b/grub-core/lib/ieee1275/tcg2.c
index 40161c2f9..945a3469b 100644
--- a/grub-core/lib/ieee1275/tcg2.c
+++ b/grub-core/lib/ieee1275/tcg2.c
@@ -56,6 +56,52 @@ grub_ieee1275_tpm_init (void)
   return GRUB_ERR_NONE;
 }
 
+int
+grub_ieee1275_ibmvtpm_2hash_ext_log (grub_uint8_t pcrindex,
+				     grub_uint32_t eventtype,
+				     const char *description,
+				     grub_size_t description_size,
+				     void *buf, grub_size_t size)
+{
+  struct tpm_2hash_ext_log
+  {
+    struct grub_ieee1275_common_hdr common;
+    grub_ieee1275_cell_t method;
+    grub_ieee1275_cell_t ihandle;
+    grub_ieee1275_cell_t size;
+    grub_ieee1275_cell_t buf;
+    grub_ieee1275_cell_t description_size;
+    grub_ieee1275_cell_t description;
+    grub_ieee1275_cell_t eventtype;
+    grub_ieee1275_cell_t pcrindex;
+    grub_ieee1275_cell_t catch_result;
+    grub_ieee1275_cell_t rc;
+  };
+  struct tpm_2hash_ext_log args;
+
+  INIT_IEEE1275_COMMON (&args.common, "call-method", 8, 2);
+  args.method = (grub_ieee1275_cell_t) "2hash-ext-log";
+  args.ihandle = grub_ieee1275_tpm_ihandle;
+  args.pcrindex = pcrindex;
+  args.eventtype = eventtype;
+  args.description = (grub_ieee1275_cell_t) description;
+  args.description_size = description_size;
+  args.buf = (grub_ieee1275_cell_t) buf;
+  args.size = (grub_ieee1275_cell_t) size;
+
+  if (IEEE1275_CALL_ENTRY_FN (&args) == -1)
+    return -1;
+
+  /*
+   * catch_result is set if firmware does not support 2hash-ext-log
+   * rc is GRUB_IEEE1275_CELL_FALSE (0) on failure
+   */
+  if ((args.catch_result) || args.rc == GRUB_IEEE1275_CELL_FALSE)
+    return -1;
+
+  return 0;
+}
+
 grub_err_t
 grub_tcg2_get_max_output_size (grub_size_t *size)
 {
@@ -155,3 +201,23 @@ grub_tcg2_submit_command (grub_size_t input_size,
 
   return GRUB_ERR_NONE;
 }
+
+grub_err_t
+grub_tcg2_cap_pcr (grub_uint8_t pcr)
+{
+  grub_uint8_t separator[4] = {0};
+  static int error_displayed = 0;
+  int rc;
+
+  rc = grub_ieee1275_ibmvtpm_2hash_ext_log (pcr, EV_SEPARATOR,
+					    separator, sizeof(separator),
+					    separator, sizeof(separator));
+  if (rc && !error_displayed)
+    {
+      error_displayed++;
+      return grub_error (GRUB_ERR_BAD_DEVICE,
+			 "2HASH-EXT-LOG failed: Firmware is likely too old.\n");
+    }
+
+  return GRUB_ERR_NONE;
+}
diff --git a/include/grub/ieee1275/tpm.h b/include/grub/ieee1275/tpm.h
index fe5cb4713..01065071b 100644
--- a/include/grub/ieee1275/tpm.h
+++ b/include/grub/ieee1275/tpm.h
@@ -27,4 +27,9 @@ extern grub_ieee1275_ihandle_t grub_ieee1275_tpm_ihandle;
 
 extern grub_err_t grub_ieee1275_tpm_init (void);
 
+extern int grub_ieee1275_ibmvtpm_2hash_ext_log (grub_uint8_t pcrindex,
+						grub_uint32_t eventtype,
+						const char *description,
+						grub_size_t description_size,
+						void *buf, grub_size_t size);
 #endif
-- 
2.43.0


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