efi_loader: add SMBIOS table measurement
TCG PC Client Platform Firmware Profile Specification
requires to measure the SMBIOS table that contains static
configuration information (e.g. Platform Manufacturer
Enterprise Number assigned by IANA, platform model number,
Vendor and Device IDs for each SMBIOS table).
The device- and environment-dependent information such as
serial number is cleared to zero or space character for
the measurement.
Existing smbios_string() function returns pointer to the string
with const qualifier, but exisintg use case is updating version
string and const qualifier must be removed.
This commit removes const qualifier from smbios_string()
return value and reuses to clear the strings for the measurement.
This commit also fixes the following compiler warning:
lib/smbios-parser.c:59:39: warning: cast to pointer from integer of
different size [-Wint-to-pointer-cast]
const struct smbios_header *header = (struct smbios_header *)entry->struct_table_address;
Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index f6d65a6..d0433ea 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -308,6 +308,8 @@
extern const efi_guid_t efi_guid_firmware_management_protocol;
/* GUID for the ESRT */
extern const efi_guid_t efi_esrt_guid;
+/* GUID of the SMBIOS table */
+extern const efi_guid_t smbios_guid;
extern char __efi_runtime_start[], __efi_runtime_stop[];
extern char __efi_runtime_rel_start[], __efi_runtime_rel_stop[];
diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h
index 8f02d4f..ca66695 100644
--- a/include/efi_tcg2.h
+++ b/include/efi_tcg2.h
@@ -210,6 +210,21 @@
u8 variable_data[1];
};
+/**
+ * struct tdUEFI_HANDOFF_TABLE_POINTERS2 - event log structure of SMBOIS tables
+ * @table_description_size: size of table description
+ * @table_description: table description
+ * @number_of_tables: number of uefi configuration table
+ * @table_entry: uefi configuration table entry
+ */
+#define SMBIOS_HANDOFF_TABLE_DESC "SmbiosTable"
+struct smbios_handoff_table_pointers2 {
+ u8 table_description_size;
+ u8 table_description[sizeof(SMBIOS_HANDOFF_TABLE_DESC)];
+ u64 number_of_tables;
+ struct efi_configuration_table table_entry[];
+} __packed;
+
struct efi_tcg2_protocol {
efi_status_t (EFIAPI * get_capability)(struct efi_tcg2_protocol *this,
struct efi_tcg2_boot_service_capability *capability);
diff --git a/include/smbios.h b/include/smbios.h
index aa6b6f3..acfcbfe 100644
--- a/include/smbios.h
+++ b/include/smbios.h
@@ -260,9 +260,9 @@
*
* @header: pointer to struct smbios_header
* @index: string index
- * @return: NULL or a valid const char pointer
+ * @return: NULL or a valid char pointer
*/
-const char *smbios_string(const struct smbios_header *header, int index);
+char *smbios_string(const struct smbios_header *header, int index);
/**
* smbios_update_version() - Update the version string
@@ -292,4 +292,17 @@
*/
int smbios_update_version_full(void *smbios_tab, const char *version);
+/**
+ * smbios_prepare_measurement() - Update smbios table for the measurement
+ *
+ * TCG specification requires to measure static configuration information.
+ * This function clear the device dependent parameters such as
+ * serial number for the measurement.
+ *
+ * @entry: pointer to a struct smbios_entry
+ * @header: pointer to a struct smbios_header
+ */
+void smbios_prepare_measurement(const struct smbios_entry *entry,
+ struct smbios_header *header);
+
#endif /* _SMBIOS_H_ */
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index 06633e9..52f71c0 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -312,6 +312,7 @@
select SHA384
select SHA512
select HASH
+ select SMBIOS_PARSER
help
Provide a EFI_TCG2_PROTOCOL implementation using the TPM hardware
of the platform.
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 352c2db..973134b 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -86,6 +86,8 @@
/* GUIDs of the Load File and Load File2 protocols */
const efi_guid_t efi_guid_load_file_protocol = EFI_LOAD_FILE_PROTOCOL_GUID;
const efi_guid_t efi_guid_load_file2_protocol = EFI_LOAD_FILE2_PROTOCOL_GUID;
+/* GUID of the SMBIOS table */
+const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
static efi_status_t EFIAPI efi_disconnect_controller(
efi_handle_t controller_handle,
diff --git a/lib/efi_loader/efi_smbios.c b/lib/efi_loader/efi_smbios.c
index 2eb4cb1..fc0b233 100644
--- a/lib/efi_loader/efi_smbios.c
+++ b/lib/efi_loader/efi_smbios.c
@@ -13,8 +13,6 @@
#include <mapmem.h>
#include <smbios.h>
-static const efi_guid_t smbios_guid = SMBIOS_TABLE_GUID;
-
/*
* Install the SMBIOS table as a configuration table.
*
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index b6f8f99..da589d0 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -15,6 +15,7 @@
#include <efi_tcg2.h>
#include <log.h>
#include <malloc.h>
+#include <smbios.h>
#include <version_string.h>
#include <tpm-v2.h>
#include <u-boot/hash-checksum.h>
@@ -1453,6 +1454,81 @@
}
/**
+ * tcg2_measure_smbios() - measure smbios table
+ *
+ * @dev: TPM device
+ * @entry: pointer to the smbios_entry structure
+ *
+ * Return: status code
+ */
+static efi_status_t
+tcg2_measure_smbios(struct udevice *dev,
+ const struct smbios_entry *entry)
+{
+ efi_status_t ret;
+ struct smbios_header *smbios_copy;
+ struct smbios_handoff_table_pointers2 *event = NULL;
+ u32 event_size;
+
+ /*
+ * TCG PC Client PFP Spec says
+ * "SMBIOS structures that contain static configuration information
+ * (e.g. Platform Manufacturer Enterprise Number assigned by IANA,
+ * platform model number, Vendor and Device IDs for each SMBIOS table)
+ * that is relevant to the security of the platform MUST be measured".
+ * Device dependent parameters such as serial number are cleared to
+ * zero or spaces for the measurement.
+ */
+ event_size = sizeof(struct smbios_handoff_table_pointers2) +
+ FIELD_SIZEOF(struct efi_configuration_table, guid) +
+ entry->struct_table_length;
+ event = calloc(1, event_size);
+ if (!event) {
+ ret = EFI_OUT_OF_RESOURCES;
+ goto out;
+ }
+
+ event->table_description_size = sizeof(SMBIOS_HANDOFF_TABLE_DESC);
+ memcpy(event->table_description, SMBIOS_HANDOFF_TABLE_DESC,
+ sizeof(SMBIOS_HANDOFF_TABLE_DESC));
+ put_unaligned_le64(1, &event->number_of_tables);
+ guidcpy(&event->table_entry[0].guid, &smbios_guid);
+ smbios_copy = (struct smbios_header *)((uintptr_t)&event->table_entry[0].table);
+ memcpy(&event->table_entry[0].table,
+ (void *)((uintptr_t)entry->struct_table_address),
+ entry->struct_table_length);
+
+ smbios_prepare_measurement(entry, smbios_copy);
+
+ ret = tcg2_measure_event(dev, 1, EV_EFI_HANDOFF_TABLES2, event_size,
+ (u8 *)event);
+ if (ret != EFI_SUCCESS)
+ goto out;
+
+out:
+ free(event);
+
+ return ret;
+}
+
+/**
+ * find_smbios_table() - find smbios table
+ *
+ * Return: pointer to the smbios table
+ */
+static void *find_smbios_table(void)
+{
+ u32 i;
+
+ for (i = 0; i < systab.nr_tables; i++) {
+ if (!guidcmp(&smbios_guid, &systab.tables[i].guid))
+ return systab.tables[i].table;
+ }
+
+ return NULL;
+}
+
+/**
* efi_tcg2_measure_efi_app_invocation() - measure efi app invocation
*
* Return: status code
@@ -1463,6 +1539,7 @@
u32 pcr_index;
struct udevice *dev;
u32 event = 0;
+ struct smbios_entry *entry;
if (tcg2_efi_app_invoked)
return EFI_SUCCESS;
@@ -1481,6 +1558,13 @@
if (ret != EFI_SUCCESS)
goto out;
+ entry = (struct smbios_entry *)find_smbios_table();
+ if (entry) {
+ ret = tcg2_measure_smbios(dev, entry);
+ if (ret != EFI_SUCCESS)
+ goto out;
+ }
+
for (pcr_index = 0; pcr_index <= 7; pcr_index++) {
ret = tcg2_measure_event(dev, pcr_index, EV_SEPARATOR,
sizeof(event), (u8 *)&event);
diff --git a/lib/smbios-parser.c b/lib/smbios-parser.c
index 34203f9..2b93929 100644
--- a/lib/smbios-parser.c
+++ b/lib/smbios-parser.c
@@ -39,10 +39,8 @@
return entry;
}
-static const struct smbios_header *next_header(const struct smbios_header *curr)
+static u8 *find_next_header(u8 *pos)
{
- u8 *pos = ((u8 *)curr) + curr->length;
-
/* search for _double_ NULL bytes */
while (!((*pos == 0) && (*(pos + 1) == 0)))
pos++;
@@ -50,13 +48,27 @@
/* step behind the double NULL bytes */
pos += 2;
- return (struct smbios_header *)pos;
+ return pos;
+}
+
+static struct smbios_header *get_next_header(struct smbios_header *curr)
+{
+ u8 *pos = ((u8 *)curr) + curr->length;
+
+ return (struct smbios_header *)find_next_header(pos);
+}
+
+static const struct smbios_header *next_header(const struct smbios_header *curr)
+{
+ u8 *pos = ((u8 *)curr) + curr->length;
+
+ return (struct smbios_header *)find_next_header(pos);
}
const struct smbios_header *smbios_header(const struct smbios_entry *entry, int type)
{
const unsigned int num_header = entry->struct_count;
- const struct smbios_header *header = (struct smbios_header *)entry->struct_table_address;
+ const struct smbios_header *header = (struct smbios_header *)((uintptr_t)entry->struct_table_address);
for (unsigned int i = 0; i < num_header; i++) {
if (header->type == type)
@@ -68,8 +80,8 @@
return NULL;
}
-static const char *string_from_smbios_table(const struct smbios_header *header,
- int idx)
+static char *string_from_smbios_table(const struct smbios_header *header,
+ int idx)
{
unsigned int i = 1;
u8 *pos;
@@ -86,10 +98,10 @@
pos++;
}
- return (const char *)pos;
+ return (char *)pos;
}
-const char *smbios_string(const struct smbios_header *header, int index)
+char *smbios_string(const struct smbios_header *header, int index)
{
if (!header)
return NULL;
@@ -109,7 +121,7 @@
if (!hdr)
return log_msg_ret("tab", -ENOENT);
bios = (struct smbios_type0 *)hdr;
- ptr = (char *)smbios_string(hdr, bios->bios_ver);
+ ptr = smbios_string(hdr, bios->bios_ver);
if (!ptr)
return log_msg_ret("str", -ENOMEDIUM);
@@ -132,3 +144,123 @@
return 0;
}
+
+struct smbios_filter_param {
+ u32 offset;
+ u32 size;
+ bool is_string;
+};
+
+struct smbios_filter_table {
+ int type;
+ struct smbios_filter_param *params;
+ u32 count;
+};
+
+struct smbios_filter_param smbios_type1_filter_params[] = {
+ {offsetof(struct smbios_type1, serial_number),
+ FIELD_SIZEOF(struct smbios_type1, serial_number), true},
+ {offsetof(struct smbios_type1, uuid),
+ FIELD_SIZEOF(struct smbios_type1, uuid), false},
+ {offsetof(struct smbios_type1, wakeup_type),
+ FIELD_SIZEOF(struct smbios_type1, wakeup_type), false},
+};
+
+struct smbios_filter_param smbios_type2_filter_params[] = {
+ {offsetof(struct smbios_type2, serial_number),
+ FIELD_SIZEOF(struct smbios_type2, serial_number), true},
+ {offsetof(struct smbios_type2, chassis_location),
+ FIELD_SIZEOF(struct smbios_type2, chassis_location), false},
+};
+
+struct smbios_filter_param smbios_type3_filter_params[] = {
+ {offsetof(struct smbios_type3, serial_number),
+ FIELD_SIZEOF(struct smbios_type3, serial_number), true},
+ {offsetof(struct smbios_type3, asset_tag_number),
+ FIELD_SIZEOF(struct smbios_type3, asset_tag_number), true},
+};
+
+struct smbios_filter_param smbios_type4_filter_params[] = {
+ {offsetof(struct smbios_type4, serial_number),
+ FIELD_SIZEOF(struct smbios_type4, serial_number), true},
+ {offsetof(struct smbios_type4, asset_tag),
+ FIELD_SIZEOF(struct smbios_type4, asset_tag), true},
+ {offsetof(struct smbios_type4, part_number),
+ FIELD_SIZEOF(struct smbios_type4, part_number), true},
+ {offsetof(struct smbios_type4, core_count),
+ FIELD_SIZEOF(struct smbios_type4, core_count), false},
+ {offsetof(struct smbios_type4, core_enabled),
+ FIELD_SIZEOF(struct smbios_type4, core_enabled), false},
+ {offsetof(struct smbios_type4, thread_count),
+ FIELD_SIZEOF(struct smbios_type4, thread_count), false},
+ {offsetof(struct smbios_type4, core_count2),
+ FIELD_SIZEOF(struct smbios_type4, core_count2), false},
+ {offsetof(struct smbios_type4, core_enabled2),
+ FIELD_SIZEOF(struct smbios_type4, core_enabled2), false},
+ {offsetof(struct smbios_type4, thread_count2),
+ FIELD_SIZEOF(struct smbios_type4, thread_count2), false},
+ {offsetof(struct smbios_type4, voltage),
+ FIELD_SIZEOF(struct smbios_type4, voltage), false},
+};
+
+struct smbios_filter_table smbios_filter_tables[] = {
+ {SMBIOS_SYSTEM_INFORMATION, smbios_type1_filter_params,
+ ARRAY_SIZE(smbios_type1_filter_params)},
+ {SMBIOS_BOARD_INFORMATION, smbios_type2_filter_params,
+ ARRAY_SIZE(smbios_type2_filter_params)},
+ {SMBIOS_SYSTEM_ENCLOSURE, smbios_type3_filter_params,
+ ARRAY_SIZE(smbios_type3_filter_params)},
+ {SMBIOS_PROCESSOR_INFORMATION, smbios_type4_filter_params,
+ ARRAY_SIZE(smbios_type4_filter_params)},
+};
+
+static void clear_smbios_table(struct smbios_header *header,
+ struct smbios_filter_param *filter,
+ u32 count)
+{
+ u32 i;
+ char *str;
+ u8 string_id;
+
+ for (i = 0; i < count; i++) {
+ if (filter[i].is_string) {
+ string_id = *((u8 *)header + filter[i].offset);
+ if (string_id == 0) /* string is empty */
+ continue;
+
+ str = smbios_string(header, string_id);
+ if (!str)
+ continue;
+
+ /* string is cleared to space, keep '\0' terminator */
+ memset(str, ' ', strlen(str));
+
+ } else {
+ memset((void *)((u8 *)header + filter[i].offset),
+ 0, filter[i].size);
+ }
+ }
+}
+
+void smbios_prepare_measurement(const struct smbios_entry *entry,
+ struct smbios_header *smbios_copy)
+{
+ u32 i, j;
+ struct smbios_header *header;
+
+ for (i = 0; i < ARRAY_SIZE(smbios_filter_tables); i++) {
+ header = smbios_copy;
+ for (j = 0; j < entry->struct_count; j++) {
+ if (header->type == smbios_filter_tables[i].type)
+ break;
+
+ header = get_next_header(header);
+ }
+ if (j >= entry->struct_count)
+ continue;
+
+ clear_smbios_table(header,
+ smbios_filter_tables[i].params,
+ smbios_filter_tables[i].count);
+ }
+}