Commit 55a82ab3 authored by Kylene Jo Hall's avatar Kylene Jo Hall Committed by Linus Torvalds
Browse files

[PATCH] tpm: add bios measurement log



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: default avatarSeiji Munetoh <munetoh@jp.ibm.com>
Signed-off-by: default avatarStefan Berger <stefanb@us.ibm.com>
Signed-off-by: default avatarReiner Sailer <sailer@us.ibm.com>
Signed-off-by: default avatarKylene Hall <kjhall@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 485a6435
......@@ -204,11 +204,13 @@ acpi_os_map_memory(acpi_physical_address phys, acpi_size size,
return AE_OK;
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);
void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
{
iounmap(virt);
}
EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);
#ifdef ACPI_FUTURE_USAGE
acpi_status
......
......@@ -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
......@@ -466,6 +466,7 @@ void tpm_remove_hardware(struct device *dev)
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 +594,8 @@ int tpm_register_hardware(struct device *dev, struct tpm_vendor_specific *entry)
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);
......
......@@ -82,6 +82,8 @@ struct tpm_chip {
struct tpm_vendor_specific *vendor;
struct dentry **bios_dir;
struct list_head list;
};
......@@ -107,3 +109,16 @@ extern ssize_t tpm_read(struct file *, char __user *, size_t, loff_t *);
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
/*
* Copyright (C) 2005 IBM Corporation
*
* Authors:
* Seiji Munetoh <munetoh@jp.ibm.com>
* Stefan Berger <stefanb@us.ibm.com>
* Reiner Sailer <sailer@watson.ibm.com>
* Kylene Hall <kjhall@us.ibm.com>
*
* 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 <linux/module.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 = 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 = 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 = 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 = 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 -ENOMEM;
}
/* 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 = 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 -ENOMEM;
}
tcg_eventlog_addr_limit = tcg_eventlog + buff->log_max_len;
acpi_os_map_memory(buff->log_start_addr, buff->log_max_len, &virt);
memcpy(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;
}
EXPORT_SYMBOL_GPL(tpm_bios_log_setup);
void tpm_bios_log_teardown(struct dentry **lst)
{
int i;
for (i = 0; i < 3; i++)
securityfs_remove(lst[i]);
}
EXPORT_SYMBOL_GPL(tpm_bios_log_teardown);
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