/* * Copyright (c) 2020-2021, Arm Limited. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #include #include #include #include #include #include #include #include #include /* Running Event Log Pointer */ static uint8_t *log_ptr; /* Pointer to the first byte past end of the Event Log buffer */ static uintptr_t log_end; /* Pointer to event_log_metadata_t */ static const event_log_metadata_t *plat_metadata_ptr; /* TCG_EfiSpecIdEvent */ static const id_event_headers_t id_event_header = { .header = { .pcr_index = PCR_0, .event_type = EV_NO_ACTION, .digest = {0}, .event_size = (uint32_t)(sizeof(id_event_struct_t) + (sizeof(id_event_algorithm_size_t) * HASH_ALG_COUNT)) }, .struct_header = { .signature = TCG_ID_EVENT_SIGNATURE_03, .platform_class = PLATFORM_CLASS_CLIENT, .spec_version_minor = TCG_SPEC_VERSION_MINOR_TPM2, .spec_version_major = TCG_SPEC_VERSION_MAJOR_TPM2, .spec_errata = TCG_SPEC_ERRATA_TPM2, .uintn_size = (uint8_t)(sizeof(unsigned int) / sizeof(uint32_t)), .number_of_algorithms = HASH_ALG_COUNT } }; static const event2_header_t locality_event_header = { /* * All EV_NO_ACTION events SHALL set * TCG_PCR_EVENT2.pcrIndex = 0, unless otherwise specified */ .pcr_index = PCR_0, /* * All EV_NO_ACTION events SHALL set * TCG_PCR_EVENT2.eventType = 03h */ .event_type = EV_NO_ACTION, /* * All EV_NO_ACTION events SHALL set TCG_PCR_EVENT2.digests to all * 0x00's for each allocated Hash algorithm */ .digests = { .count = HASH_ALG_COUNT } }; /* * Record a measurement as a TCG_PCR_EVENT2 event * * @param[in] hash Pointer to hash data of TCG_DIGEST_SIZE bytes * @param[in] metadata_ptr Pointer to event_log_metadata_t structure * * There must be room for storing this new event into the event log buffer. */ static void event_log_record(const uint8_t *hash, const event_log_metadata_t *metadata_ptr) { void *ptr = log_ptr; uint32_t name_len; assert(hash != NULL); assert(metadata_ptr != NULL); assert(metadata_ptr->name != NULL); /* event_log_init() must have been called prior to this. */ assert(log_ptr != NULL); name_len = (uint32_t)strlen(metadata_ptr->name) + 1U; /* Check for space in Event Log buffer */ assert(((uintptr_t)ptr + (uint32_t)EVENT2_HDR_SIZE + name_len) < log_end); /* * As per TCG specifications, firmware components that are measured * into PCR[0] must be logged in the event log using the event type * EV_POST_CODE. */ /* TCG_PCR_EVENT2.PCRIndex */ ((event2_header_t *)ptr)->pcr_index = metadata_ptr->pcr; /* TCG_PCR_EVENT2.EventType */ ((event2_header_t *)ptr)->event_type = EV_POST_CODE; /* TCG_PCR_EVENT2.Digests.Count */ ptr = (uint8_t *)ptr + offsetof(event2_header_t, digests); ((tpml_digest_values *)ptr)->count = HASH_ALG_COUNT; /* TCG_PCR_EVENT2.Digests[] */ ptr = (uint8_t *)((uintptr_t)ptr + offsetof(tpml_digest_values, digests)); /* TCG_PCR_EVENT2.Digests[].AlgorithmId */ ((tpmt_ha *)ptr)->algorithm_id = TPM_ALG_ID; /* TCG_PCR_EVENT2.Digests[].Digest[] */ ptr = (uint8_t *)((uintptr_t)ptr + offsetof(tpmt_ha, digest)); /* Copy digest */ (void)memcpy(ptr, (const void *)hash, TCG_DIGEST_SIZE); /* TCG_PCR_EVENT2.EventSize */ ptr = (uint8_t *)((uintptr_t)ptr + TCG_DIGEST_SIZE); ((event2_data_t *)ptr)->event_size = name_len; /* Copy event data to TCG_PCR_EVENT2.Event */ (void)memcpy((void *)(((event2_data_t *)ptr)->event), (const void *)metadata_ptr->name, name_len); /* End of event data */ log_ptr = (uint8_t *)((uintptr_t)ptr + offsetof(event2_data_t, event) + name_len); } /* * Initialise Event Log global variables, used during the recording * of various payload measurements into the Event Log buffer * * @param[in] event_log_start Base address of Event Log buffer * @param[in] event_log_finish End address of Event Log buffer, * it is a first byte past end of the * buffer */ void event_log_init(uint8_t *event_log_start, uint8_t *event_log_finish) { assert(event_log_start != NULL); assert(event_log_finish > event_log_start); log_ptr = event_log_start; log_end = (uintptr_t)event_log_finish; /* Get pointer to platform's event_log_metadata_t structure */ plat_metadata_ptr = plat_event_log_get_metadata(); assert(plat_metadata_ptr != NULL); } /* * Initialises Event Log by writing Specification ID and * Startup Locality events */ void event_log_write_header(void) { const char locality_signature[] = TCG_STARTUP_LOCALITY_SIGNATURE; void *ptr = log_ptr; /* event_log_init() must have been called prior to this. */ assert(log_ptr != NULL); /* * Add Specification ID Event first * * Copy TCG_EfiSpecIDEventStruct structure header */ (void)memcpy(ptr, (const void *)&id_event_header, sizeof(id_event_header)); ptr = (uint8_t *)((uintptr_t)ptr + sizeof(id_event_header)); /* TCG_EfiSpecIdEventAlgorithmSize structure */ ((id_event_algorithm_size_t *)ptr)->algorithm_id = TPM_ALG_ID; ((id_event_algorithm_size_t *)ptr)->digest_size = TCG_DIGEST_SIZE; ptr = (uint8_t *)((uintptr_t)ptr + sizeof(id_event_algorithm_size_t)); /* * TCG_EfiSpecIDEventStruct.vendorInfoSize * No vendor data */ ((id_event_struct_data_t *)ptr)->vendor_info_size = 0; ptr = (uint8_t *)((uintptr_t)ptr + offsetof(id_event_struct_data_t, vendor_info)); /* * The Startup Locality event should be placed in the log before * any event which extends PCR[0]. * * Ref. TCG PC Client Platform Firmware Profile 9.4.5.3 */ /* Copy Startup Locality Event Header */ (void)memcpy(ptr, (const void *)&locality_event_header, sizeof(locality_event_header)); ptr = (uint8_t *)((uintptr_t)ptr + sizeof(locality_event_header)); /* TCG_PCR_EVENT2.Digests[].AlgorithmId */ ((tpmt_ha *)ptr)->algorithm_id = TPM_ALG_ID; /* TCG_PCR_EVENT2.Digests[].Digest[] */ (void)memset(&((tpmt_ha *)ptr)->digest, 0, TPM_ALG_ID); ptr = (uint8_t *)((uintptr_t)ptr + offsetof(tpmt_ha, digest) + TCG_DIGEST_SIZE); /* TCG_PCR_EVENT2.EventSize */ ((event2_data_t *)ptr)->event_size = (uint32_t)sizeof(startup_locality_event_t); ptr = (uint8_t *)((uintptr_t)ptr + offsetof(event2_data_t, event)); /* TCG_EfiStartupLocalityEvent.Signature */ (void)memcpy(ptr, (const void *)locality_signature, sizeof(TCG_STARTUP_LOCALITY_SIGNATURE)); /* * TCG_EfiStartupLocalityEvent.StartupLocality = 0: * the platform's boot firmware */ ((startup_locality_event_t *)ptr)->startup_locality = 0U; log_ptr = (uint8_t *)((uintptr_t)ptr + sizeof(startup_locality_event_t)); } /* * Calculate and write hash of image, configuration data, etc. * to Event Log. * * @param[in] data_base Address of data * @param[in] data_size Size of data * @param[in] data_id Data ID * @return: * 0 = success * < 0 = error */ int event_log_measure_and_record(uintptr_t data_base, uint32_t data_size, uint32_t data_id) { unsigned char hash_data[MBEDTLS_MD_MAX_SIZE]; int rc; const event_log_metadata_t *metadata_ptr = plat_metadata_ptr; /* Get the metadata associated with this image. */ while ((metadata_ptr->id != INVALID_ID) && (metadata_ptr->id != data_id)) { metadata_ptr++; } assert(metadata_ptr->id != INVALID_ID); /* Calculate hash */ rc = crypto_mod_calc_hash((unsigned int)MBEDTLS_MD_ID, (void *)data_base, data_size, hash_data); if (rc != 0) { return rc; } event_log_record(hash_data, metadata_ptr); return 0; } /* * Get current Event Log buffer size i.e. used space of Event Log buffer * * @param[in] event_log_start Base Pointer to Event Log buffer * * @return: current Size of Event Log buffer */ size_t event_log_get_cur_size(uint8_t *event_log_start) { assert(event_log_start != NULL); assert(log_ptr >= event_log_start); return (size_t)((uintptr_t)log_ptr - (uintptr_t)event_log_start); }