diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/char/tpm/tpm-sysfs.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c new file mode 100644 index 000000000..54c71473a --- /dev/null +++ b/drivers/char/tpm/tpm-sysfs.c @@ -0,0 +1,529 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2004 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> + * + * Copyright (C) 2013 Obsidian Research Corp + * Jason Gunthorpe <jgunthorpe@obsidianresearch.com> + * + * sysfs filesystem inspection interface to the TPM + */ +#include <linux/device.h> +#include "tpm.h" + +struct tpm_readpubek_out { + u8 algorithm[4]; + u8 encscheme[2]; + u8 sigscheme[2]; + __be32 paramsize; + u8 parameters[12]; + __be32 keysize; + u8 modulus[256]; + u8 checksum[20]; +} __packed; + +#define READ_PUBEK_RESULT_MIN_BODY_SIZE (28 + 256) +#define TPM_ORD_READPUBEK 124 + +static ssize_t pubek_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_buf tpm_buf; + struct tpm_readpubek_out *out; + int i; + char *str = buf; + struct tpm_chip *chip = to_tpm_chip(dev); + char anti_replay[20]; + + memset(&anti_replay, 0, sizeof(anti_replay)); + + if (tpm_try_get_ops(chip)) + return 0; + + if (tpm_buf_init(&tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK)) + goto out_ops; + + tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay)); + + if (tpm_transmit_cmd(chip, &tpm_buf, READ_PUBEK_RESULT_MIN_BODY_SIZE, + "attempting to read the PUBEK")) + goto out_buf; + + out = (struct tpm_readpubek_out *)&tpm_buf.data[10]; + str += + sprintf(str, + "Algorithm: %4ph\n" + "Encscheme: %2ph\n" + "Sigscheme: %2ph\n" + "Parameters: %12ph\n" + "Modulus length: %d\n" + "Modulus:\n", + out->algorithm, + out->encscheme, + out->sigscheme, + out->parameters, + be32_to_cpu(out->keysize)); + + for (i = 0; i < 256; i += 16) + str += sprintf(str, "%16ph\n", &out->modulus[i]); + +out_buf: + tpm_buf_destroy(&tpm_buf); +out_ops: + tpm_put_ops(chip); + return str - buf; +} +static DEVICE_ATTR_RO(pubek); + +static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + cap_t cap; + u8 digest[TPM_DIGEST_SIZE]; + u32 i, j, num_pcrs; + char *str = buf; + struct tpm_chip *chip = to_tpm_chip(dev); + + if (tpm_try_get_ops(chip)) + return 0; + + if (tpm1_getcap(chip, TPM_CAP_PROP_PCR, &cap, + "attempting to determine the number of PCRS", + sizeof(cap.num_pcrs))) { + tpm_put_ops(chip); + return 0; + } + + num_pcrs = be32_to_cpu(cap.num_pcrs); + for (i = 0; i < num_pcrs; i++) { + if (tpm1_pcr_read(chip, i, digest)) { + str = buf; + break; + } + str += sprintf(str, "PCR-%02d: ", i); + for (j = 0; j < TPM_DIGEST_SIZE; j++) + str += sprintf(str, "%02X ", digest[j]); + str += sprintf(str, "\n"); + } + tpm_put_ops(chip); + return str - buf; +} +static DEVICE_ATTR_RO(pcrs); + +static ssize_t enabled_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + ssize_t rc = 0; + cap_t cap; + + if (tpm_try_get_ops(chip)) + return 0; + + if (tpm1_getcap(chip, TPM_CAP_FLAG_PERM, &cap, + "attempting to determine the permanent enabled state", + sizeof(cap.perm_flags))) + goto out_ops; + + rc = sprintf(buf, "%d\n", !cap.perm_flags.disable); +out_ops: + tpm_put_ops(chip); + return rc; +} +static DEVICE_ATTR_RO(enabled); + +static ssize_t active_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + ssize_t rc = 0; + cap_t cap; + + if (tpm_try_get_ops(chip)) + return 0; + + if (tpm1_getcap(chip, TPM_CAP_FLAG_PERM, &cap, + "attempting to determine the permanent active state", + sizeof(cap.perm_flags))) + goto out_ops; + + rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated); +out_ops: + tpm_put_ops(chip); + return rc; +} +static DEVICE_ATTR_RO(active); + +static ssize_t owned_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + ssize_t rc = 0; + cap_t cap; + + if (tpm_try_get_ops(chip)) + return 0; + + if (tpm1_getcap(to_tpm_chip(dev), TPM_CAP_PROP_OWNER, &cap, + "attempting to determine the owner state", + sizeof(cap.owned))) + goto out_ops; + + rc = sprintf(buf, "%d\n", cap.owned); +out_ops: + tpm_put_ops(chip); + return rc; +} +static DEVICE_ATTR_RO(owned); + +static ssize_t temp_deactivated_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + ssize_t rc = 0; + cap_t cap; + + if (tpm_try_get_ops(chip)) + return 0; + + if (tpm1_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_VOL, &cap, + "attempting to determine the temporary state", + sizeof(cap.stclear_flags))) + goto out_ops; + + rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated); +out_ops: + tpm_put_ops(chip); + return rc; +} +static DEVICE_ATTR_RO(temp_deactivated); + +static ssize_t caps_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + struct tpm1_version *version; + ssize_t rc = 0; + char *str = buf; + cap_t cap; + + if (tpm_try_get_ops(chip)) + return 0; + + if (tpm1_getcap(chip, TPM_CAP_PROP_MANUFACTURER, &cap, + "attempting to determine the manufacturer", + sizeof(cap.manufacturer_id))) + goto out_ops; + + str += sprintf(str, "Manufacturer: 0x%x\n", + be32_to_cpu(cap.manufacturer_id)); + + /* TPM 1.2 */ + if (!tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap, + "attempting to determine the 1.2 version", + sizeof(cap.version2))) { + version = &cap.version2.version; + goto out_print; + } + + /* TPM 1.1 */ + if (tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap, + "attempting to determine the 1.1 version", + sizeof(cap.version1))) { + goto out_ops; + } + + version = &cap.version1; + +out_print: + str += sprintf(str, + "TCG version: %d.%d\nFirmware version: %d.%d\n", + version->major, version->minor, + version->rev_major, version->rev_minor); + + rc = str - buf; + +out_ops: + tpm_put_ops(chip); + return rc; +} +static DEVICE_ATTR_RO(caps); + +static ssize_t cancel_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + + if (tpm_try_get_ops(chip)) + return 0; + + chip->ops->cancel(chip); + tpm_put_ops(chip); + return count; +} +static DEVICE_ATTR_WO(cancel); + +static ssize_t durations_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + + if (chip->duration[TPM_LONG] == 0) + return 0; + + return sprintf(buf, "%d %d %d [%s]\n", + jiffies_to_usecs(chip->duration[TPM_SHORT]), + jiffies_to_usecs(chip->duration[TPM_MEDIUM]), + jiffies_to_usecs(chip->duration[TPM_LONG]), + chip->duration_adjusted + ? "adjusted" : "original"); +} +static DEVICE_ATTR_RO(durations); + +static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + + return sprintf(buf, "%d %d %d %d [%s]\n", + jiffies_to_usecs(chip->timeout_a), + jiffies_to_usecs(chip->timeout_b), + jiffies_to_usecs(chip->timeout_c), + jiffies_to_usecs(chip->timeout_d), + chip->timeout_adjusted + ? "adjusted" : "original"); +} +static DEVICE_ATTR_RO(timeouts); + +static ssize_t tpm_version_major_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tpm_chip *chip = to_tpm_chip(dev); + + return sprintf(buf, "%s\n", chip->flags & TPM_CHIP_FLAG_TPM2 + ? "2" : "1"); +} +static DEVICE_ATTR_RO(tpm_version_major); + +static struct attribute *tpm1_dev_attrs[] = { + &dev_attr_pubek.attr, + &dev_attr_pcrs.attr, + &dev_attr_enabled.attr, + &dev_attr_active.attr, + &dev_attr_owned.attr, + &dev_attr_temp_deactivated.attr, + &dev_attr_caps.attr, + &dev_attr_cancel.attr, + &dev_attr_durations.attr, + &dev_attr_timeouts.attr, + &dev_attr_tpm_version_major.attr, + NULL, +}; + +static struct attribute *tpm2_dev_attrs[] = { + &dev_attr_tpm_version_major.attr, + NULL +}; + +static const struct attribute_group tpm1_dev_group = { + .attrs = tpm1_dev_attrs, +}; + +static const struct attribute_group tpm2_dev_group = { + .attrs = tpm2_dev_attrs, +}; + +struct tpm_pcr_attr { + int alg_id; + int pcr; + struct device_attribute attr; +}; + +#define to_tpm_pcr_attr(a) container_of(a, struct tpm_pcr_attr, attr) + +static ssize_t pcr_value_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct tpm_pcr_attr *ha = to_tpm_pcr_attr(attr); + struct tpm_chip *chip = to_tpm_chip(dev); + struct tpm_digest digest; + int i; + int digest_size = 0; + int rc; + char *str = buf; + + for (i = 0; i < chip->nr_allocated_banks; i++) + if (ha->alg_id == chip->allocated_banks[i].alg_id) + digest_size = chip->allocated_banks[i].digest_size; + /* should never happen */ + if (!digest_size) + return -EINVAL; + + digest.alg_id = ha->alg_id; + rc = tpm_pcr_read(chip, ha->pcr, &digest); + if (rc) + return rc; + for (i = 0; i < digest_size; i++) + str += sprintf(str, "%02X", digest.digest[i]); + str += sprintf(str, "\n"); + + return str - buf; +} + +/* + * The following set of defines represents all the magic to build + * the per hash attribute groups for displaying each bank of PCRs. + * The only slight problem with this approach is that every PCR is + * hard coded to be present, so you don't know if an PCR is missing + * until a cat of the file returns -EINVAL + * + * Also note you must ignore checkpatch warnings in this macro + * code. This is deep macro magic that checkpatch.pl doesn't + * understand. + */ + +/* Note, this must match TPM2_PLATFORM_PCR which is fixed at 24. */ +#define _TPM_HELPER(_alg, _hash, F) \ + F(_alg, _hash, 0) \ + F(_alg, _hash, 1) \ + F(_alg, _hash, 2) \ + F(_alg, _hash, 3) \ + F(_alg, _hash, 4) \ + F(_alg, _hash, 5) \ + F(_alg, _hash, 6) \ + F(_alg, _hash, 7) \ + F(_alg, _hash, 8) \ + F(_alg, _hash, 9) \ + F(_alg, _hash, 10) \ + F(_alg, _hash, 11) \ + F(_alg, _hash, 12) \ + F(_alg, _hash, 13) \ + F(_alg, _hash, 14) \ + F(_alg, _hash, 15) \ + F(_alg, _hash, 16) \ + F(_alg, _hash, 17) \ + F(_alg, _hash, 18) \ + F(_alg, _hash, 19) \ + F(_alg, _hash, 20) \ + F(_alg, _hash, 21) \ + F(_alg, _hash, 22) \ + F(_alg, _hash, 23) + +/* ignore checkpatch warning about trailing ; in macro. */ +#define PCR_ATTR(_alg, _hash, _pcr) \ + static struct tpm_pcr_attr dev_attr_pcr_##_hash##_##_pcr = { \ + .alg_id = _alg, \ + .pcr = _pcr, \ + .attr = { \ + .attr = { \ + .name = __stringify(_pcr), \ + .mode = 0444 \ + }, \ + .show = pcr_value_show \ + } \ + }; + +#define PCR_ATTRS(_alg, _hash) \ + _TPM_HELPER(_alg, _hash, PCR_ATTR) + +/* ignore checkpatch warning about trailing , in macro. */ +#define PCR_ATTR_VAL(_alg, _hash, _pcr) \ + &dev_attr_pcr_##_hash##_##_pcr.attr.attr, + +#define PCR_ATTR_GROUP_ARRAY(_alg, _hash) \ + static struct attribute *pcr_group_attrs_##_hash[] = { \ + _TPM_HELPER(_alg, _hash, PCR_ATTR_VAL) \ + NULL \ + } + +#define PCR_ATTR_GROUP(_alg, _hash) \ + static struct attribute_group pcr_group_##_hash = { \ + .name = "pcr-" __stringify(_hash), \ + .attrs = pcr_group_attrs_##_hash \ + } + +#define PCR_ATTR_BUILD(_alg, _hash) \ + PCR_ATTRS(_alg, _hash) \ + PCR_ATTR_GROUP_ARRAY(_alg, _hash); \ + PCR_ATTR_GROUP(_alg, _hash) +/* + * End of macro structure to build an attribute group containing 24 + * PCR value files for each supported hash algorithm + */ + +/* + * The next set of macros implements the cleverness for each hash to + * build a static attribute group called pcr_group_<hash> which can be + * added to chip->groups[]. + * + * The first argument is the TPM algorithm id and the second is the + * hash used as both the suffix and the group name. Note: the group + * name is a directory in the top level tpm class with the name + * pcr-<hash>, so it must not clash with any other names already + * in the sysfs directory. + */ +PCR_ATTR_BUILD(TPM_ALG_SHA1, sha1); +PCR_ATTR_BUILD(TPM_ALG_SHA256, sha256); +PCR_ATTR_BUILD(TPM_ALG_SHA384, sha384); +PCR_ATTR_BUILD(TPM_ALG_SHA512, sha512); +PCR_ATTR_BUILD(TPM_ALG_SM3_256, sm3); + + +void tpm_sysfs_add_device(struct tpm_chip *chip) +{ + int i; + + WARN_ON(chip->groups_cnt != 0); + + if (tpm_is_firmware_upgrade(chip)) + return; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) + chip->groups[chip->groups_cnt++] = &tpm2_dev_group; + else + chip->groups[chip->groups_cnt++] = &tpm1_dev_group; + + /* add one group for each bank hash */ + for (i = 0; i < chip->nr_allocated_banks; i++) { + switch (chip->allocated_banks[i].alg_id) { + case TPM_ALG_SHA1: + chip->groups[chip->groups_cnt++] = &pcr_group_sha1; + break; + case TPM_ALG_SHA256: + chip->groups[chip->groups_cnt++] = &pcr_group_sha256; + break; + case TPM_ALG_SHA384: + chip->groups[chip->groups_cnt++] = &pcr_group_sha384; + break; + case TPM_ALG_SHA512: + chip->groups[chip->groups_cnt++] = &pcr_group_sha512; + break; + case TPM_ALG_SM3_256: + chip->groups[chip->groups_cnt++] = &pcr_group_sm3; + break; + default: + /* + * If triggers, send a patch to add both a + * PCR_ATTR_BUILD() macro above for the + * missing algorithm as well as an additional + * case in this switch statement. + */ + dev_err(&chip->dev, + "TPM with unsupported bank algorithm 0x%04x", + chip->allocated_banks[i].alg_id); + break; + } + } + + /* + * This will only trigger if someone has added an additional + * hash to the tpm_algorithms enum without incrementing + * TPM_MAX_HASHES. + */ + WARN_ON(chip->groups_cnt > TPM_MAX_HASHES + 1); +} |