diff options
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/Kconfig | 11 | ||||
| -rw-r--r-- | samples/Makefile | 1 | ||||
| -rw-r--r-- | samples/tsm-mr/Makefile | 2 | ||||
| -rw-r--r-- | samples/tsm-mr/tsm_mr_sample.c | 131 |
4 files changed, 145 insertions, 0 deletions
diff --git a/samples/Kconfig b/samples/Kconfig index 09011be2391a..6ade17cb16b4 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -184,6 +184,17 @@ config SAMPLE_TIMER bool "Timer sample" depends on CC_CAN_LINK && HEADERS_INSTALL +config SAMPLE_TSM_MR + tristate "TSM measurement sample" + select TSM_MEASUREMENTS + select VIRT_DRIVERS + help + Build a sample module that emulates MRs (Measurement Registers) and + exposes them to user mode applications through the TSM sysfs + interface (/sys/class/misc/tsm_mr_sample/emulated_mr/). + + The module name will be tsm-mr-sample when built as a module. + config SAMPLE_UHID bool "UHID sample" depends on CC_CAN_LINK && HEADERS_INSTALL diff --git a/samples/Makefile b/samples/Makefile index bf6e6fca5410..c95bac31851c 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -43,3 +43,4 @@ obj-$(CONFIG_SAMPLES_RUST) += rust/ obj-$(CONFIG_SAMPLE_DAMON_WSSE) += damon/ obj-$(CONFIG_SAMPLE_DAMON_PRCL) += damon/ obj-$(CONFIG_SAMPLE_HUNG_TASK) += hung_task/ +obj-$(CONFIG_SAMPLE_TSM_MR) += tsm-mr/ diff --git a/samples/tsm-mr/Makefile b/samples/tsm-mr/Makefile new file mode 100644 index 000000000000..587c3947b3a7 --- /dev/null +++ b/samples/tsm-mr/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_SAMPLE_TSM_MR) += tsm_mr_sample.o diff --git a/samples/tsm-mr/tsm_mr_sample.c b/samples/tsm-mr/tsm_mr_sample.c new file mode 100644 index 000000000000..a2c652148639 --- /dev/null +++ b/samples/tsm-mr/tsm_mr_sample.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2024-2005 Intel Corporation. All rights reserved. */ + +#define pr_fmt(x) KBUILD_MODNAME ": " x + +#include <linux/module.h> +#include <linux/tsm-mr.h> +#include <linux/miscdevice.h> +#include <crypto/hash.h> + +static struct { + u8 static_mr[SHA384_DIGEST_SIZE]; + u8 config_mr[SHA512_DIGEST_SIZE]; + u8 rtmr0[SHA256_DIGEST_SIZE]; + u8 rtmr1[SHA384_DIGEST_SIZE]; + u8 report_digest[SHA512_DIGEST_SIZE]; +} sample_report = { + .static_mr = "static_mr", + .config_mr = "config_mr", + .rtmr0 = "rtmr0", + .rtmr1 = "rtmr1", +}; + +static int sample_report_refresh(const struct tsm_measurements *tm) +{ + struct crypto_shash *tfm; + int rc; + + tfm = crypto_alloc_shash(hash_algo_name[HASH_ALGO_SHA512], 0, 0); + if (IS_ERR(tfm)) { + pr_err("crypto_alloc_shash failed: %ld\n", PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + + rc = crypto_shash_tfm_digest(tfm, (u8 *)&sample_report, + offsetof(typeof(sample_report), + report_digest), + sample_report.report_digest); + crypto_free_shash(tfm); + if (rc) + pr_err("crypto_shash_tfm_digest failed: %d\n", rc); + return rc; +} + +static int sample_report_extend_mr(const struct tsm_measurements *tm, + const struct tsm_measurement_register *mr, + const u8 *data) +{ + SHASH_DESC_ON_STACK(desc, 0); + int rc; + + desc->tfm = crypto_alloc_shash(hash_algo_name[mr->mr_hash], 0, 0); + if (IS_ERR(desc->tfm)) { + pr_err("crypto_alloc_shash failed: %ld\n", PTR_ERR(desc->tfm)); + return PTR_ERR(desc->tfm); + } + + rc = crypto_shash_init(desc); + if (!rc) + rc = crypto_shash_update(desc, mr->mr_value, mr->mr_size); + if (!rc) + rc = crypto_shash_finup(desc, data, mr->mr_size, mr->mr_value); + crypto_free_shash(desc->tfm); + if (rc) + pr_err("SHA calculation failed: %d\n", rc); + return rc; +} + +#define MR_(mr, hash) .mr_value = &sample_report.mr, TSM_MR_(mr, hash) +static const struct tsm_measurement_register sample_mrs[] = { + /* static MR, read-only */ + { MR_(static_mr, SHA384) }, + /* config MR, read-only */ + { MR_(config_mr, SHA512) | TSM_MR_F_NOHASH }, + /* RTMR, direct extension prohibited */ + { MR_(rtmr0, SHA256) | TSM_MR_F_LIVE }, + /* RTMR, direct extension allowed */ + { MR_(rtmr1, SHA384) | TSM_MR_F_RTMR }, + /* RTMR, crypto agile, alaised to rtmr0 and rtmr1, respectively */ + { .mr_value = &sample_report.rtmr0, + TSM_MR_(rtmr_crypto_agile, SHA256) | TSM_MR_F_RTMR }, + { .mr_value = &sample_report.rtmr1, + TSM_MR_(rtmr_crypto_agile, SHA384) | TSM_MR_F_RTMR }, + /* sha512 digest of the whole structure */ + { MR_(report_digest, SHA512) | TSM_MR_F_LIVE }, +}; +#undef MR_ + +static struct tsm_measurements sample_tm = { + .mrs = sample_mrs, + .nr_mrs = ARRAY_SIZE(sample_mrs), + .refresh = sample_report_refresh, + .write = sample_report_extend_mr, +}; + +static const struct attribute_group *sample_groups[] = { + NULL, + NULL, +}; + +static struct miscdevice sample_misc_dev = { + .name = KBUILD_MODNAME, + .minor = MISC_DYNAMIC_MINOR, + .groups = sample_groups, +}; + +static int __init tsm_mr_sample_init(void) +{ + int rc; + + sample_groups[0] = tsm_mr_create_attribute_group(&sample_tm); + if (IS_ERR(sample_groups[0])) + return PTR_ERR(sample_groups[0]); + + rc = misc_register(&sample_misc_dev); + if (rc) + tsm_mr_free_attribute_group(sample_groups[0]); + return rc; +} + +static void __exit tsm_mr_sample_exit(void) +{ + misc_deregister(&sample_misc_dev); + tsm_mr_free_attribute_group(sample_groups[0]); +} + +module_init(tsm_mr_sample_init); +module_exit(tsm_mr_sample_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Sample module using tsm-mr to expose emulated MRs"); |