According to the TCG specifications measurements or hashes of the BIOS
code and data are extended into TPM PCRS and a log is kept in an ACPI
table of these extensions for later validation if desired. This patch
exports the values in the ACPI table through a security-fs seq_file.
Signed-off-by: Seiji Munetoh <[email protected]>
Signed-off-by: Stefan Berger <[email protected]>
Signed-off-by: Reiner Sailer <sailer
Signed-off-by: Kylene Hall <[email protected]>
---
diff -uprbBN --exclude='*.o' --exclude='*.ko' --exclude='*.orig' --exclude='*.rej' --exclude='.*' --exclude='*~' --exclude='tpm_logical*' --exclude=Kconfig linux-2.6.15-rc2/drivers/char/tpm/Makefile linux-2.6.15-rc1/drivers/char/tpm/Makefile
--- linux-2.6.15-rc2/drivers/char/tpm/Makefile 2005-11-19 21:25:03.000000000 -0600
+++ linux-2.6.15-rc1/drivers/char/tpm/Makefile 2005-11-21 10:45:36.000000000 -0600
@@ -2,6 +2,9 @@
# Makefile for the kernel tpm device drivers.
#
obj-$(CONFIG_TCG_TPM) += tpm.o
+ifdef CONFIG_ACPI
+ obj-$(CONFIG_TCG_TPM) += tpm_bios.o
+endif
obj-$(CONFIG_TCG_NSC) += tpm_nsc.o
obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o
obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o
diff -uprbBN --exclude='*.o' --exclude='*.ko' --exclude='*.orig' --exclude='*.rej' --exclude='.*' --exclude='*~' --exclude='tpm_logical*' --exclude=Kconfig linux-2.6.15-rc2/drivers/char/tpm/tpm_bios.c linux-2.6.15-rc1/drivers/char/tpm/tpm_bios.c
diff -uprbBN --exclude='*.o' --exclude='*.ko' --exclude='*.orig' --exclude='*.rej' --exclude='.*' --exclude='*~' --exclude='tpm_logical*' --exclude=Kconfig linux-2.6.15-rc2/drivers/char/tpm/tpm.c linux-2.6.15-rc1/drivers/char/tpm/tpm.c
--- linux-2.6.15-rc2/drivers/char/tpm/tpm.c 2005-11-19 21:25:03.000000000 -0600
+++ linux-2.6.15-rc1/drivers/char/tpm/tpm.c 2005-11-21 16:57:45.000000000 -0600
@@ -466,6 +556,7 @@ void tpm_remove_hardware(struct device *
kfree(chip->vendor->miscdev.name);
sysfs_remove_group(&dev->kobj, chip->vendor->attr_group);
+ tpm_bios_log_teardown(chip->bios_dir);
dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES ] &=
~(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
@@ -593,6 +684,8 @@ dev_num_search_complete:
sysfs_create_group(&dev->kobj, chip->vendor->attr_group);
+ chip->bios_dir = tpm_bios_log_setup(devname);
+
return 0;
}
EXPORT_SYMBOL_GPL(tpm_register_hardware);
diff -uprbBN --exclude='*.o' --exclude='*.ko' --exclude='*.orig' --exclude='*.rej' --exclude='.*' --exclude='*~' --exclude='tpm_logical*' --exclude=Kconfig linux-2.6.15-rc2/drivers/char/tpm/tpm.h linux-2.6.15-rc1/drivers/char/tpm/tpm.h
--- linux-2.6.15-rc2/drivers/char/tpm/tpm.h 2005-11-19 21:25:03.000000000 -0600
+++ linux-2.6.15-rc1/drivers/char/tpm/tpm.h 2005-11-22 10:40:16.000000000 -0600
@@ -82,6 +85,8 @@ struct tpm_chip {
struct tpm_vendor_specific *vendor;
+ struct dentry **bios_dir;
+
struct list_head list;
};
@@ -107,3 +112,16 @@ extern ssize_t tpm_read(struct file *, c
extern void tpm_remove_hardware(struct device *);
extern int tpm_pm_suspend(struct device *, pm_message_t);
extern int tpm_pm_resume(struct device *);
+
+#ifdef CONFIG_ACPI
+extern struct dentry** tpm_bios_log_setup(char*);
+extern void tpm_bios_log_teardown(struct dentry**);
+#else
+static inline struct dentry* tpm_bios_log_setup(char* name)
+{
+ return NULL;
+}
+static inline void tpm_bios_log_teardown(struct dentry** dir)
+{
+}
+#endif
--- linux-2.6.15-rc2/drivers/char/tpm/tpm_bios.c 1969-12-31 18:00:00.000000000 -0600
+++ linux-2.6.15-rc1/drivers/char/tpm/tpm_bios.c 2005-11-22 13:50:27.000000000 -0600
@@ -0,0 +1,504 @@
+/*
+ * Copyright (C) 2005 IBM Corporation
+ *
+ * Authors:
+ * Seiji Munetoh <[email protected]>
+ * Stefan Berger <[email protected]>
+ * Reiner Sailer <[email protected]>
+ * Kylene Hall <[email protected]>
+ *
+ * Access to the eventlog extended by the TCG BIOS of PC platform
+ *
+ * This program 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
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/seq_file.h>
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <acpi/acpi.h>
+#include <acpi/actypes.h>
+#include <acpi/actbl.h>
+#include "tpm.h"
+
+#define TCG_EVENT_NAME_LEN_MAX 255
+#define MAX_TEXT_EVENT 1000 /* Max event string length */
+#define ACPI_TCPA_SIG "TCPA" /* 0x41504354 /'TCPA' */
+
+struct acpi_tcpa {
+ struct acpi_table_header hdr;
+ u16 reserved;
+ u32 log_max_len __attribute__ ((packed));
+ u32 log_start_addr __attribute__ ((packed));
+};
+
+struct tcpa_event {
+ u32 pcr_index;
+ u32 event_type;
+ u8 pcr_value[20]; /* SHA1 */
+ u32 event_size;
+ u8 event_data[0];
+};
+
+enum tcpa_event_types {
+ PREBOOT = 0,
+ POST_CODE,
+ UNUSED,
+ NO_ACTION,
+ SEPARATOR,
+ ACTION,
+ EVENT_TAG,
+ SCRTM_CONTENTS,
+ SCRTM_VERSION,
+ CPU_MICROCODE,
+ PLATFORM_CONFIG_FLAGS,
+ TABLE_OF_DEVICES,
+ COMPACT_HASH,
+ IPL,
+ IPL_PARTITION_DATA,
+ NONHOST_CODE,
+ NONHOST_CONFIG,
+ NONHOST_INFO,
+};
+
+static const char* tcpa_event_type_strings[] = {
+ "PREBOOT",
+ "POST CODE",
+ "",
+ "NO ACTION",
+ "SEPARATOR",
+ "ACTION",
+ "EVENT TAG",
+ "S-CRTM Contents",
+ "S-CRTM Version",
+ "CPU Microcode",
+ "Platform Config Flags",
+ "Table of Devices",
+ "Compact Hash",
+ "IPL",
+ "IPL Partition Data",
+ "Non-Host Code",
+ "Non-Host Config",
+ "Non-Host Info"
+};
+
+enum tcpa_pc_event_ids {
+ SMBIOS = 1,
+ BIS_CERT,
+ POST_BIOS_ROM,
+ ESCD,
+ CMOS,
+ NVRAM,
+ OPTION_ROM_EXEC,
+ OPTION_ROM_CONFIG,
+ OPTION_ROM_MICROCODE,
+ S_CRTM_VERSION,
+ S_CRTM_CONTENTS,
+ POST_CONTENTS,
+};
+
+static const char* tcpa_pc_event_id_strings[] = {
+ ""
+ "SMBIOS",
+ "BIS Certificate",
+ "POST BIOS ",
+ "ESCD ",
+ "CMOS",
+ "NVRAM",
+ "Option ROM",
+ "Option ROM config",
+ "Option ROM microcode",
+ "S-CRTM Version",
+ "S-CRTM Contents",
+ "S-CRTM POST Contents"
+
+};
+
+/* (Binary) bios measurement buffer */
+static void *tcg_eventlog;
+static void *tcg_eventlog_addr_limit; /* MAX */
+
+/* returns pointer to start of pos. entry of tcg log */
+static void *tpm_bios_measurements_start(struct seq_file *m, loff_t * pos)
+{
+ loff_t i;
+ void *addr = tcg_eventlog;
+ struct tcpa_event *event;
+
+ /* read over *pos measurements */
+ for (i = 0; i < *pos; i++) {
+ event = (struct tcpa_event *) addr;
+
+ if ((addr + sizeof(struct tcpa_event)) <
+ tcg_eventlog_addr_limit) {
+ if (event->event_type == 0 && event->event_size == 0)
+ return NULL;
+ addr +=
+ sizeof(struct tcpa_event) + event->event_size;
+ }
+ }
+
+ /* now check if current entry is valid */
+ if ((addr + sizeof(struct tcpa_event)) >= tcg_eventlog_addr_limit)
+ return NULL;
+
+ event = (struct tcpa_event *) addr;
+
+ if ((event->event_type == 0 && event->event_size == 0) ||
+ ((addr + sizeof(struct tcpa_event) + event->event_size) >=
+ tcg_eventlog_addr_limit))
+ return NULL;
+
+ return addr;
+}
+
+static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
+ loff_t * pos)
+{
+ struct tcpa_event *event = (struct tcpa_event *) v;
+
+ v += sizeof(struct tcpa_event) + event->event_size;
+
+ /* now check if current entry is valid */
+ if ((v + sizeof(struct tcpa_event)) >= tcg_eventlog_addr_limit)
+ return NULL;
+
+ event = (struct tcpa_event *) v;
+
+ if (event->event_type == 0 && event->event_size == 0)
+ return NULL;
+
+ if ((event->event_type == 0 && event->event_size == 0) ||
+ ((v + sizeof(struct tcpa_event) + event->event_size) >=
+ tcg_eventlog_addr_limit))
+ return NULL;
+
+ (*pos)++;
+ return v;
+}
+
+static void tpm_bios_measurements_stop(struct seq_file *m, void *v)
+{
+}
+
+static int get_event_name(char* dest, struct tcpa_event *event, unsigned char* event_entry )
+{
+ const char *name = "";
+ char data[40] = "";
+ int i, n_len = 0, d_len = 0;
+ u32 event_id, event_data_size;
+
+ switch(event->event_type) {
+ case PREBOOT:
+ case POST_CODE:
+ case UNUSED:
+ case NO_ACTION:
+ case SCRTM_CONTENTS:
+ case SCRTM_VERSION:
+ case CPU_MICROCODE:
+ case PLATFORM_CONFIG_FLAGS:
+ case TABLE_OF_DEVICES:
+ case COMPACT_HASH:
+ case IPL:
+ case IPL_PARTITION_DATA:
+ case NONHOST_CODE:
+ case NONHOST_CONFIG:
+ case NONHOST_INFO:
+ name = tcpa_event_type_strings[event->event_type];
+ n_len = strlen(name);
+ break;
+ case SEPARATOR:
+ case ACTION:
+ if (MAX_TEXT_EVENT > event->event_size) {
+ name = event_entry;
+ n_len = event->event_size;
+ }
+ break;
+ case EVENT_TAG:
+ event_id = be32_to_cpu(event_entry);
+ event_data_size = be32_to_cpu(&event_entry[4]);
+
+ /* ToDo Row data -> Base64 */
+
+ switch (event_id) {
+ case SMBIOS:
+ case BIS_CERT:
+ case CMOS:
+ case NVRAM:
+ case OPTION_ROM_EXEC:
+ case OPTION_ROM_CONFIG:
+ case OPTION_ROM_MICROCODE:
+ case S_CRTM_VERSION:
+ case S_CRTM_CONTENTS:
+ case POST_CONTENTS:
+ name = tcpa_pc_event_id_strings[event_id];
+ n_len = strlen(name);
+ break;
+ case POST_BIOS_ROM:
+ case ESCD:
+ name = tcpa_pc_event_id_strings[event_id];
+ n_len = strlen(name);
+ for (i = 0; i < 20; i++)
+ d_len += sprintf(data, "%02x", event_entry[8 + i]);
+ break;
+ default:
+ break;
+ }
+ default:
+ break;
+ }
+
+ return snprintf( dest, MAX_TEXT_EVENT, "[%.*s%.*s]", n_len, name, d_len, data );
+
+}
+
+static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v)
+{
+
+ char *eventname;
+ char data[4];
+ u32 help;
+ int i, len;
+ struct tcpa_event *event = (struct tcpa_event *) v;
+ unsigned char *event_entry =
+ (unsigned char *) (v + sizeof(struct tcpa_event));
+
+ eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
+ if (!eventname) {
+ printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
+ __func__);
+ return -EFAULT;
+ }
+
+ /* 1st: PCR used is in little-endian format (4 bytes) */
+ help = le32_to_cpu(event->pcr_index);
+ memcpy(data, &help, 4);
+ for (i = 0; i < 4; i++)
+ seq_putc(m, data[i]);
+
+ /* 2nd: SHA1 (20 bytes) */
+ for (i = 0; i < 20; i++)
+ seq_putc(m, event->pcr_value[i]);
+
+ /* 3rd: event type identifier (4 bytes) */
+ help = le32_to_cpu(event->event_type);
+ memcpy(data, &help, 4);
+ for (i = 0; i < 4; i++)
+ seq_putc(m, data[i]);
+
+ len = 0;
+
+ len += get_event_name(eventname, event, event_entry);
+
+ /* 4th: filename <= 255 + \'0' delimiter */
+ if (len > TCG_EVENT_NAME_LEN_MAX)
+ len = TCG_EVENT_NAME_LEN_MAX;
+
+ for (i = 0; i < len; i++)
+ seq_putc(m, eventname[i]);
+
+ /* 5th: delimiter */
+ seq_putc(m, '\0');
+
+ return 0;
+}
+
+static int tpm_bios_measurements_release(struct inode *inode,
+ struct file *file)
+{
+ if (tcg_eventlog) {
+ kfree(tcg_eventlog);
+ tcg_eventlog = NULL;
+ }
+ return seq_release(inode, file);
+}
+
+static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
+{
+ int len = 0;
+ int i;
+ char *eventname;
+
+ struct tcpa_event *event = (struct tcpa_event *) v;
+ unsigned char *event_entry =
+ (unsigned char *) (v + sizeof(struct tcpa_event));
+
+ eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
+ if (!eventname) {
+ printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
+ __func__);
+ return -EFAULT;
+ }
+
+ seq_printf(m, "%2d ", event->pcr_index);
+
+ /* 2nd: SHA1 */
+ for (i = 0; i < 20; i++)
+ seq_printf(m, "%02x", event->pcr_value[i]);
+
+ /* 3rd: event type identifier */
+ seq_printf(m, " %02x", event->event_type);
+
+ len += get_event_name(eventname, event, event_entry);
+
+ /* 4th: eventname <= max + \'0' delimiter */
+ seq_printf(m, " %s\n", eventname);
+
+ return 0;
+}
+
+static struct seq_operations tpm_ascii_b_measurments_seqops = {
+ .start = tpm_bios_measurements_start,
+ .next = tpm_bios_measurements_next,
+ .stop = tpm_bios_measurements_stop,
+ .show = tpm_ascii_bios_measurements_show
+};
+
+static struct seq_operations tpm_binary_b_measurments_seqops = {
+ .start = tpm_bios_measurements_start,
+ .next = tpm_bios_measurements_next,
+ .stop = tpm_bios_measurements_stop,
+ .show = tpm_binary_bios_measurements_show
+};
+
+/* read binary bios log */
+static int read_log(void)
+{
+ struct acpi_tcpa *buff;
+ acpi_status status;
+ void *virt;
+
+ if (tcg_eventlog != NULL) {
+ printk(KERN_ERR
+ "%s: ERROR - Eventlog already initialized\n",
+ __func__);
+ return -EFAULT;
+ }
+
+ /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
+ status = acpi_get_firmware_table(ACPI_TCPA_SIG, 1,
+ ACPI_LOGICAL_ADDRESSING,
+ (struct acpi_table_header **)
+ &buff);
+
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_ERR "%s: ERROR - Could not get TCPA table\n",
+ __func__);
+ return -EIO;
+ }
+
+ if (buff->log_max_len == 0) {
+ printk(KERN_ERR "%s: ERROR - TCPA log area empty\n",
+ __func__);
+ return -EIO;
+ }
+
+ /* malloc EventLog space */
+ tcg_eventlog = kmalloc(buff->log_max_len, GFP_KERNEL);
+ if (!tcg_eventlog) {
+ printk
+ ("%s: ERROR - Not enough Memory for BIOS measurements\n",
+ __func__);
+ return -EFAULT;
+ }
+
+ tcg_eventlog_addr_limit = tcg_eventlog + buff->log_max_len;
+
+ acpi_os_map_memory(buff->log_start_addr, buff->log_max_len, &virt);
+
+ memcpy((void *) tcg_eventlog, virt, buff->log_max_len);
+
+ acpi_os_unmap_memory(virt, buff->log_max_len);
+ return 0;
+}
+
+static int tpm_ascii_bios_measurements_open(struct inode *inode,
+ struct file *file)
+{
+ int err;
+
+ if ((err = read_log()))
+ return err;
+
+ /* now register seq file */
+ return seq_open(file, &tpm_ascii_b_measurments_seqops);
+}
+
+struct file_operations tpm_ascii_bios_measurements_ops = {
+ .open = tpm_ascii_bios_measurements_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tpm_bios_measurements_release,
+};
+
+static int tpm_binary_bios_measurements_open(struct inode *inode,
+ struct file *file)
+{
+ int err;
+
+ if ((err = read_log()))
+ return err;
+
+ /* now register seq file */
+ return seq_open(file, &tpm_binary_b_measurments_seqops);
+}
+
+struct file_operations tpm_binary_bios_measurements_ops = {
+ .open = tpm_binary_bios_measurements_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tpm_bios_measurements_release,
+};
+
+struct dentry **tpm_bios_log_setup(char *name)
+{
+ struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
+
+ tpm_dir = securityfs_create_dir(name, NULL);
+ if (!tpm_dir)
+ goto out;
+
+ bin_file =
+ securityfs_create_file("binary_bios_measurements",
+ S_IRUSR | S_IRGRP, tpm_dir, NULL,
+ &tpm_binary_bios_measurements_ops);
+ if (!bin_file)
+ goto out_tpm;
+
+ ascii_file =
+ securityfs_create_file("ascii_bios_measurements",
+ S_IRUSR | S_IRGRP, tpm_dir, NULL,
+ &tpm_ascii_bios_measurements_ops);
+ if (!ascii_file)
+ goto out_bin;
+
+ ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
+ if (!ret)
+ goto out_ascii;
+
+ ret[0] = ascii_file;
+ ret[1] = bin_file;
+ ret[2] = tpm_dir;
+
+ return ret;
+
+out_ascii:
+ securityfs_remove(ascii_file);
+out_bin:
+ securityfs_remove(bin_file);
+out_tpm:
+ securityfs_remove(tpm_dir);
+out:
+ return NULL;
+}
+
+void tpm_bios_log_teardown(struct dentry **lst)
+{
+ int i;
+
+ for (i = 0; i < 3; i++)
+ securityfs_remove(lst[i]);
+}
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