[RFC][Patch 6/6] integrity: TPM internal kernel interface
From: Mimi Zohar
Date: Thu Mar 08 2007 - 10:52:52 EST
Index: linux-2.6.21-rc3-mm2/drivers/char/tpm/tpm.c
===================================================================
--- linux-2.6.21-rc3-mm2.orig/drivers/char/tpm/tpm.c
+++ linux-2.6.21-rc3-mm2/drivers/char/tpm/tpm.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2004,2007 IBM Corporation
*
* Authors:
* Leendert van Doorn <leendert@xxxxxxxxxxxxxx>
@@ -25,6 +25,12 @@
#include <linux/poll.h>
#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/crypto.h>
+#include <linux/fs.h>
+#include <asm/scatterlist.h>
#include "tpm.h"
enum tpm_const {
@@ -47,6 +53,8 @@ enum tpm_duration {
static LIST_HEAD(tpm_chip_list);
static DEFINE_SPINLOCK(driver_lock);
static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
+#define TPM_CHIP_NUM_MASK 0x0000ffff
+#define TPM_CHIP_TYPE_SHIFT 16
/*
* Array with one entry per ordinal defining the maximum amount
@@ -363,7 +371,7 @@ EXPORT_SYMBOL_GPL(tpm_calc_ordinal_durat
/*
* Internal kernel interface to transmit TPM commands
*/
-static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
+ssize_t tpm_transmit(struct tpm_chip *chip, char *buf,
size_t bufsiz)
{
ssize_t rc;
@@ -422,6 +430,7 @@ out:
up(&chip->tpm_mutex);
return rc;
}
+EXPORT_SYMBOL_GPL(tpm_transmit);
#define TPM_DIGEST_SIZE 20
#define TPM_ERROR_SIZE 10
@@ -665,6 +674,7 @@ ssize_t tpm_show_temp_deactivated(struct
}
EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
+#define READ_PCR_RESULT_SIZE 30
static const u8 pcrread[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 14, /* length */
@@ -713,6 +723,93 @@ out:
}
EXPORT_SYMBOL_GPL(tpm_show_pcrs);
+static struct tpm_chip* tpm_chip_lookup(int chip_num, int chip_typ)
+{
+ struct tpm_chip *pos;
+
+ spin_lock(&driver_lock);
+ list_for_each_entry(pos, &tpm_chip_list, list)
+ if ((chip_num == TPM_ANY_NUM ||
+ pos->dev_num == chip_num ) &&
+ (chip_typ == TPM_ANY_TYPE)){
+ spin_unlock(&driver_lock);
+ return pos;
+ }
+
+ spin_unlock(&driver_lock);
+ return NULL;
+}
+
+/*
+ * Return 0 on success. On error pass along error code.
+ * chip_id Upper 2 bytes equal ANY, HW_ONLY or SW_ONLY
+ * Lower 2 bytes equal tpm idx # or AN&
+ * res_buf must fit a TPM_PCR (20 bytes) or NULL if you don't care
+ */
+int tpm_pcr_read( u32 chip_id, int pcr_idx, u8* res_buf, int res_buf_size )
+{
+ u8 data[READ_PCR_RESULT_SIZE];
+ int rc;
+ __be32 index;
+ int chip_num = chip_id & TPM_CHIP_NUM_MASK;
+ struct tpm_chip* chip;
+
+ if ( res_buf && res_buf_size < TPM_DIGEST_SIZE )
+ return -ENOSPC;
+
+ if ( (chip = tpm_chip_lookup( chip_num,
+ chip_id >> TPM_CHIP_TYPE_SHIFT ) ) == NULL )
+ return -ENODEV;
+
+ memcpy(data, pcrread, sizeof(pcrread));
+ index = cpu_to_be32(pcr_idx);
+ memcpy(data + 10, &index, 4);
+ if ((rc = tpm_transmit(chip, data, sizeof(data))) > 0 )
+ rc = be32_to_cpu(*((u32*)(data+6)));
+
+ if ( rc == 0 && res_buf )
+ memcpy(res_buf, data+10, TPM_DIGEST_SIZE);
+
+ return rc;
+
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_read);
+
+#define EXTEND_PCR_SIZE 34
+static const u8 pcrextend[] = {
+ 0, 193, /* TPM_TAG_RQU_COMMAND */
+ 0, 0, 0, 34, /* length */
+ 0, 0, 0, 20, /* TPM_ORD_Extend */
+ 0, 0, 0, 0 /* PCR index */
+};
+
+/*
+ * Return 0 on success. On error pass along error code.
+ * chip_id Upper 2 bytes equal ANY, HW_ONLY or SW_ONLY
+ * Lower 2 bytes equal tpm idx # or ANY
+ */
+int tpm_pcr_extend(u32 chip_id, int pcr_idx, const u8* hash)
+{
+ u8 data[EXTEND_PCR_SIZE];
+ int rc;
+ __be32 index;
+ int chip_num = chip_id & TPM_CHIP_NUM_MASK;
+ struct tpm_chip* chip;
+
+ if ( (chip = tpm_chip_lookup( chip_num,
+ chip_id >> TPM_CHIP_TYPE_SHIFT )) == NULL )
+ return -ENODEV;
+
+ memcpy(data, pcrextend, sizeof(pcrextend));
+ index = cpu_to_be32(pcr_idx);
+ memcpy(data + 10, &index, 4);
+ memcpy( data + 14, hash, TPM_DIGEST_SIZE );
+ if ((rc = tpm_transmit(chip, data, sizeof(data))) > 0 )
+ rc = be32_to_cpu(*((u32*)(data+6)));
+ return rc;
+}
+EXPORT_SYMBOL_GPL(tpm_pcr_extend);
+
#define READ_PUBEK_RESULT_SIZE 314
static const u8 readpubek[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
@@ -944,13 +1041,13 @@ int tpm_release(struct inode *inode, str
spin_lock(&driver_lock);
file->private_data = NULL;
+ spin_unlock(&driver_lock);
chip->num_opens--;
del_singleshot_timer_sync(&chip->user_read_timer);
flush_scheduled_work();
atomic_set(&chip->data_pending, 0);
put_device(chip->dev);
kfree(chip->data_buffer);
- spin_unlock(&driver_lock);
return 0;
}
EXPORT_SYMBOL_GPL(tpm_release);
Index: linux-2.6.21-rc3-mm2/drivers/char/tpm/tpm.h
===================================================================
--- linux-2.6.21-rc3-mm2.orig/drivers/char/tpm/tpm.h
+++ linux-2.6.21-rc3-mm2/drivers/char/tpm/tpm.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2004, 2007 IBM Corporation
*
* Authors:
* Leendert van Doorn <leendert@xxxxxxxxxxxxxx>
@@ -25,6 +25,7 @@
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/io.h>
+#include <linux/tpm.h>
enum tpm_timeout {
TPM_TIMEOUT = 5, /* msecs */
Index: linux-2.6.21-rc3-mm2/include/linux/tpm.h
===================================================================
--- /dev/null
+++ linux-2.6.21-rc3-mm2/include/linux/tpm.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2004,2007 IBM Corporation
+ *
+ * Authors:
+ * Leendert van Doorn <leendert@xxxxxxxxxxxxxx>
+ * Dave Safford <safford@xxxxxxxxxxxxxx>
+ * Reiner Sailer <sailer@xxxxxxxxxxxxxx>
+ * Kylene Hall <kjhall@xxxxxxxxxx>
+ *
+ * Maintained by: <tpmdd_devel@xxxxxxxxxxxxxxxxxxxxx>
+ *
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * 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, version 2 of the
+ * License.
+ *
+ */
+#ifndef __LINUX_TPM_H__
+#define __LINUX_TPM_H__
+
+#define CONFIG_TCG_TPM 1
+#define PCI_DEVICE_ID_AMD_8111_LPC 0x7468
+
+/*
+ * Chip type is one of these values in the upper two bytes of chip_id
+ */
+enum tpm_chip_type {
+ TPM_HW_TYPE = 0x0,
+ TPM_SW_TYPE = 0x1,
+ TPM_ANY_TYPE = 0xFFFF,
+};
+
+/*
+ * Chip num is this value or a valid tpm idx in lower two bytes of chip_id
+ */
+enum tpm_chip_num {
+ TPM_ANY_NUM = 0xFFFF,
+};
+
+
+#ifdef CONFIG_TCG_TPM
+extern int tpm_pcr_read(u32 chip_id, int pcr_idx, u8* res_buf, int res_buf_size);
+extern int tpm_pcr_extend(u32 chip_id, int pcr_idx, const u8* hash);
+#else
+static inline int tpm_pcr_read(u32 chip_id, int pcr_idx, u8* res_buf,
+ int res_buf_size)
+{
+ return -1;
+}
+
+static inline int tpm_pcr_extend(u32 chip_id, int pcr_idx, const u8* hash)
+{
+ return -1;
+}
+#endif
+#endif
+
-
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