diff options
| -rw-r--r-- | drivers/char/tpm/tpm.c | 129 | ||||
| -rw-r--r-- | drivers/char/tpm/tpm.h | 18 | ||||
| -rw-r--r-- | include/linux/tpm.h | 35 |
3 files changed, 163 insertions, 19 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 9b9eb76..62a5682 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -661,28 +661,125 @@ ssize_t tpm_show_temp_deactivated(struct device * dev, } EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated); -static const u8 pcrread[] = { - 0, 193, /* TPM_TAG_RQU_COMMAND */ - 0, 0, 0, 14, /* length */ - 0, 0, 0, 21, /* TPM_ORD_PcrRead */ - 0, 0, 0, 0 /* PCR index */ +/* + * tpm_chip_find_get - return tpm_chip for given chip number + */ +static struct tpm_chip *tpm_chip_find_get(int chip_num) +{ + struct tpm_chip *pos; + + rcu_read_lock(); + list_for_each_entry_rcu(pos, &tpm_chip_list, list) { + if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num) + continue; + + if (try_module_get(pos->dev->driver->owner)) + break; + } + rcu_read_unlock(); + return pos; +} + +#define TPM_ORDINAL_PCRREAD cpu_to_be32(21) +#define READ_PCR_RESULT_SIZE 30 +static struct tpm_input_header pcrread_header = { + .tag = TPM_TAG_RQU_COMMAND, + .length = cpu_to_be32(14), + .ordinal = TPM_ORDINAL_PCRREAD +}; + +int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf) +{ + int rc; + struct tpm_cmd_t cmd; + + cmd.header.in = pcrread_header; + cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx); + BUILD_BUG_ON(cmd.header.in.length > READ_PCR_RESULT_SIZE); + rc = transmit_cmd(chip, &cmd, cmd.header.in.length, + "attempting to read a pcr value"); + + if (rc == 0) + memcpy(res_buf, cmd.params.pcrread_out.pcr_result, + TPM_DIGEST_SIZE); + return rc; +} + +/** + * tpm_pcr_read - read a pcr value + * @chip_num: tpm idx # or ANY + * @pcr_idx: pcr idx to retrieve + * @res_buf: TPM_PCR value + * size of res_buf is 20 bytes (or NULL if you don't care) + * + * The TPM driver should be built-in, but for whatever reason it + * isn't, protect against the chip disappearing, by incrementing + * the module usage count. + */ +int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf) +{ + struct tpm_chip *chip; + int rc; + + chip = tpm_chip_find_get(chip_num); + if (chip == NULL) + return -ENODEV; + rc = __tpm_pcr_read(chip, pcr_idx, res_buf); + module_put(chip->dev->driver->owner); + return rc; +} +EXPORT_SYMBOL_GPL(tpm_pcr_read); + +/** + * tpm_pcr_extend - extend pcr value with hash + * @chip_num: tpm idx # or AN& + * @pcr_idx: pcr idx to extend + * @hash: hash value used to extend pcr value + * + * The TPM driver should be built-in, but for whatever reason it + * isn't, protect against the chip disappearing, by incrementing + * the module usage count. + */ +#define TPM_ORD_PCR_EXTEND cpu_to_be32(20) +#define EXTEND_PCR_SIZE 34 +static struct tpm_input_header pcrextend_header = { + .tag = TPM_TAG_RQU_COMMAND, + .length = cpu_to_be32(34), + .ordinal = TPM_ORD_PCR_EXTEND }; +int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) +{ + struct tpm_cmd_t cmd; + int rc; + struct tpm_chip *chip; + + chip = tpm_chip_find_get(chip_num); + if (chip == NULL) + return -ENODEV; + + cmd.header.in = pcrextend_header; + BUILD_BUG_ON(be32_to_cpu(cmd.header.in.length) > EXTEND_PCR_SIZE); + cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx); + memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE); + rc = transmit_cmd(chip, &cmd, cmd.header.in.length, + "attempting extend a PCR value"); + + module_put(chip->dev->driver->owner); + return rc; +} +EXPORT_SYMBOL_GPL(tpm_pcr_extend); + ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr, char *buf) { cap_t cap; - u8 *data; + u8 digest[TPM_DIGEST_SIZE]; ssize_t rc; int i, j, num_pcrs; - __be32 index; char *str = buf; struct tpm_chip *chip = dev_get_drvdata(dev); - data = kzalloc(TPM_INTERNAL_RESULT_SIZE, GFP_KERNEL); - if (!data) - return -ENOMEM; - rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap, "attempting to determine the number of PCRS"); if (rc) @@ -690,20 +787,14 @@ ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr, num_pcrs = be32_to_cpu(cap.num_pcrs); for (i = 0; i < num_pcrs; i++) { - memcpy(data, pcrread, sizeof(pcrread)); - index = cpu_to_be32(i); - memcpy(data + 10, &index, 4); - rc = transmit_cmd(chip, (struct tpm_cmd_t *)data, - TPM_INTERNAL_RESULT_SIZE, - "attempting to read a PCR"); + rc = __tpm_pcr_read(chip, i, digest); if (rc) break; str += sprintf(str, "PCR-%02d: ", i); for (j = 0; j < TPM_DIGEST_SIZE; j++) - str += sprintf(str, "%02X ", *(data + 10 + j)); + str += sprintf(str, "%02X ", digest[j]); str += sprintf(str, "\n"); } - kfree(data); return str - buf; } EXPORT_SYMBOL_GPL(tpm_show_pcrs); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index d64f6b7..8e00b4d 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -26,6 +26,7 @@ #include <linux/miscdevice.h> #include <linux/platform_device.h> #include <linux/io.h> +#include <linux/tpm.h> enum tpm_timeout { TPM_TIMEOUT = 5, /* msecs */ @@ -234,11 +235,28 @@ typedef union { struct tpm_output_header out; } tpm_cmd_header; +#define TPM_DIGEST_SIZE 20 +struct tpm_pcrread_out { + u8 pcr_result[TPM_DIGEST_SIZE]; +}__attribute__((packed)); + +struct tpm_pcrread_in { + __be32 pcr_idx; +}__attribute__((packed)); + +struct tpm_pcrextend_in { + __be32 pcr_idx; + u8 hash[TPM_DIGEST_SIZE]; +}__attribute__((packed)); + typedef union { struct tpm_getcap_params_out getcap_out; struct tpm_readpubek_params_out readpubek_out; u8 readpubek_out_buffer[sizeof(struct tpm_readpubek_params_out)]; struct tpm_getcap_params_in getcap_in; + struct tpm_pcrread_in pcrread_in; + struct tpm_pcrread_out pcrread_out; + struct tpm_pcrextend_in pcrextend_in; } tpm_cmd_params; struct tpm_cmd_t { diff --git a/include/linux/tpm.h b/include/linux/tpm.h new file mode 100644 index 0000000..3338b3f --- /dev/null +++ b/include/linux/tpm.h @@ -0,0 +1,35 @@ +/* + * Copyright (C) 2004,2007,2008 IBM Corporation + * + * Authors: + * Leendert van Doorn <leendert@watson.ibm.com> + * Dave Safford <safford@watson.ibm.com> + * Reiner Sailer <sailer@watson.ibm.com> + * Kylene Hall <kjhall@us.ibm.com> + * Debora Velarde <dvelarde@us.ibm.com> + * + * Maintained by: <tpmdd_devel@lists.sourceforge.net> + * + * 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__ + +/* + * Chip num is this value or a valid tpm idx + */ +#define TPM_ANY_NUM 0xFFFF + +#if defined(CONFIG_TCG_TPM) + +extern int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf); +extern int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash); +#endif +#endif |