From: Stefan Berger <stef...@linux.ibm.com>
Add support for trusted boot using a vTPM 2.0 on the IBM IEEE1275
PowerPC platform. With this patch grub now measures text and binary data
into the TPM's PCRs 8 and 9 in the same way as the x86_64 platform
does.
This patch requires Daniel Axtens's patches for claiming more memory.
Cc: Eric Snowberg <eric.snowb...@oracle.com>
Signed-off-by: Stefan Berger <stef...@linux.ibm.com>
---
docs/grub.texi | 3 +-
grub-core/Makefile.core.def | 7 ++
grub-core/commands/ieee1275/ibmvtpm.c | 160 ++++++++++++++++++++++++++
include/grub/ieee1275/ieee1275.h | 1 +
4 files changed, 170 insertions(+), 1 deletion(-)
create mode 100644 grub-core/commands/ieee1275/ibmvtpm.c
diff --git a/docs/grub.texi b/docs/grub.texi
index f8b4b3b21..23d2f2d90 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -6023,7 +6023,8 @@ tpm module is loaded. As such it is recommended that the
tpm module be built
into @file{core.img} in order to avoid a potential gap in measurement between
@file{core.img} being loaded and the tpm module being loaded.
-Measured boot is currently only supported on EFI platforms.
+Measured boot is currently only supported on EFI and IBM IEEE1275 PowerPC
+platforms.
@node Lockdown
@section Lockdown when booting on a secure setup
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 8022e1c0a..e6ac50704 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -1118,6 +1118,13 @@ module = {
enable = powerpc_ieee1275;
};
+module = {
+ name = tpm;
+ common = commands/tpm.c;
+ ieee1275 = commands/ieee1275/ibmvtpm.c;
+ enable = powerpc_ieee1275;
+};
+
module = {
name = terminal;
common = commands/terminal.c;
diff --git a/grub-core/commands/ieee1275/ibmvtpm.c
b/grub-core/commands/ieee1275/ibmvtpm.c
new file mode 100644
index 000000000..1762f51f2
--- /dev/null
+++ b/grub-core/commands/ieee1275/ibmvtpm.c
@@ -0,0 +1,160 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2021 Free Software Foundation, Inc.
+ * Copyright (C) 2021 IBM Corporation
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * IBM vTPM support code.
+ */
+
+#include <grub/err.h>
+#include <grub/types.h>
+#include <grub/tpm.h>
+#include <grub/ieee1275/ieee1275.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+
+static grub_ieee1275_ihandle_t tpm_ihandle;
+static grub_uint8_t tpm_version;
+
+static void
+tpm_get_tpm_version (void)
+{
+ grub_ieee1275_phandle_t vtpm;
+ char buffer[20];
+
+ if (!grub_ieee1275_finddevice ("/vdevice/vtpm", &vtpm) &&
+ !grub_ieee1275_get_property (vtpm, "compatible", buffer,
+ sizeof (buffer), NULL) &&
+ !grub_strcmp (buffer, "IBM,vtpm20"))
+ tpm_version = 2;
+}
+
+static grub_ieee1275_ihandle_t
+tpm_init (void)
+{
+ static int init_called = 0;
+
+ if (!init_called)
+ {
+ if (grub_ieee1275_open ("/vdevice/vtpm", &tpm_ihandle) < 0)
+ tpm_ihandle = GRUB_IEEE1275_IHANDLE_INVALID;
+
+ tpm_get_tpm_version ();
+
+ init_called = 1;
+ }
+
+ return tpm_ihandle;
+}
+
+static grub_err_t
+tpm_handle_find (grub_ieee1275_ihandle_t *tpm_handle)
+{
+ *tpm_handle = tpm_init ();
+ if (*tpm_handle == GRUB_IEEE1275_IHANDLE_INVALID)
+ return GRUB_ERR_UNKNOWN_DEVICE;
+
+ return GRUB_ERR_NONE;
+}
+
+static int
+ibmvtpm_2hash_ext_log (grub_uint32_t ihandle,
+ 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;
+ }
+ args;
+
+ INIT_IEEE1275_COMMON (&args.common, "call-method", 8, 2);
+ args.method = (grub_ieee1275_cell_t) "2hash-ext-log";
+ args.ihandle = 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 TRUE (-1) on success
+ */
+ if ((args.catch_result) || args.rc == GRUB_IEEE1275_CELL_FALSE)
+ return -1;
+
+ return 0;
+}
+
+static grub_err_t
+tpm2_log_event (grub_ieee1275_ihandle_t tpm_handle, unsigned char *buf,
+ grub_size_t size, grub_uint8_t pcr,
+ const char *description)
+{
+ static int error_displayed = 0;
+ int err;
+
+ err = ibmvtpm_2hash_ext_log (tpm_handle,
+ pcr, EV_IPL,
+ description,
+ grub_strlen(description) + 1,
+ buf, size);
+ if (err && !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;
+}
+
+grub_err_t
+grub_tpm_measure (unsigned char *buf, grub_size_t size, grub_uint8_t pcr,
+ const char *description)
+{
+ grub_ieee1275_ihandle_t tpm_handle;
+
+ /* Absence of a TPM isn't a failure. */
+ if (tpm_handle_find (&tpm_handle) != GRUB_ERR_NONE)
+ return GRUB_ERR_NONE;
+
+ grub_dprintf ("tpm", "log_event, pcr = %d, size = 0x%" PRIxGRUB_SIZE ",
%s\n",
+ pcr, size, description);
+
+ if (tpm_version == 2)
+ return tpm2_log_event (tpm_handle, buf, size, pcr, description);
+
+ return GRUB_ERR_NONE;
+}
diff --git a/include/grub/ieee1275/ieee1275.h b/include/grub/ieee1275/ieee1275.h
index c5402dc1c..c81b00bc5 100644
--- a/include/grub/ieee1275/ieee1275.h
+++ b/include/grub/ieee1275/ieee1275.h
@@ -25,6 +25,7 @@
#include <grub/machine/ieee1275.h>
#define GRUB_IEEE1275_CELL_INVALID ((grub_ieee1275_cell_t) -1)
+#define GRUB_IEEE1275_CELL_FALSE ((grub_ieee1275_cell_t) 0)
struct grub_ieee1275_mem_region
{
--
2.25.1
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