// SPDX-License-Identifier: GPL-2.0+ /* * Defines APIs that allow an OS to interact with UEFI firmware to query * information about the device. * https://trustedcomputinggroup.org/resource/tcg-efi-protocol-specification/ * * Copyright (c) 2020, Linaro Limited */ #define LOG_CATEGORY LOGC_EFI #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** * struct event_log_buffer - internal eventlog management structure * * @buffer: eventlog buffer * @final_buffer: finalevent config table buffer * @pos: current position of 'buffer' * @final_pos: current position of 'final_buffer' * @get_event_called: true if GetEventLog has been invoked at least once * @ebs_called: true if ExitBootServices has been invoked * @truncated: true if the 'buffer' is truncated */ struct event_log_buffer { void *buffer; void *final_buffer; size_t pos; /* eventlog position */ size_t final_pos; /* final events config table position */ size_t last_event_size; bool get_event_called; bool ebs_called; bool truncated; }; static struct event_log_buffer event_log; static bool tcg2_efi_app_invoked; /* * When requesting TPM2_CAP_TPM_PROPERTIES the value is on a standard offset. * Since the current tpm2_get_capability() response buffers starts at * 'union tpmu_capabilities data' of 'struct tpms_capability_data', calculate * the response size and offset once for all consumers */ #define TPM2_RESPONSE_BUFFER_SIZE (sizeof(struct tpms_capability_data) - \ offsetof(struct tpms_capability_data, data)) #define properties_offset (offsetof(struct tpml_tagged_tpm_property, tpm_property) + \ offsetof(struct tpms_tagged_property, value)) static const efi_guid_t efi_guid_tcg2_protocol = EFI_TCG2_PROTOCOL_GUID; static const efi_guid_t efi_guid_final_events = EFI_TCG2_FINAL_EVENTS_TABLE_GUID; struct variable_info { const u16 *name; bool accept_empty; u32 pcr_index; }; static struct variable_info secure_variables[] = { {u"SecureBoot", true, 7}, {u"PK", true, 7}, {u"KEK", true, 7}, {u"db", true, 7}, {u"dbx", true, 7}, {u"dbt", false, 7}, {u"dbr", false, 7}, {u"DeployedMode", false, 1}, {u"AuditMode", false, 1}, }; static bool is_tcg2_protocol_installed(void) { struct efi_handler *handler; efi_status_t ret; ret = efi_search_protocol(efi_root, &efi_guid_tcg2_protocol, &handler); return ret == EFI_SUCCESS; } /* tcg2_agile_log_append - Append an agile event to an eventlog * * @pcr_index: PCR index * @event_type: type of event added * @digest_list: list of digest algorithms to add * @size: size of event * @event: event to add * @log: log buffer to append the event * * @Return: status code */ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type, struct tpml_digest_values *digest_list, u32 size, u8 event[]) { void *log = (void *)((uintptr_t)event_log.buffer + event_log.pos); u32 event_size = size + tcg2_event_get_size(digest_list); struct efi_tcg2_final_events_table *final_event; efi_status_t ret = EFI_SUCCESS; /* if ExitBootServices hasn't been called update the normal log */ if (!event_log.ebs_called) { if (event_log.truncated || event_log.pos + event_size > TPM2_EVENT_LOG_SIZE) { event_log.truncated = true; return EFI_VOLUME_FULL; } tcg2_log_append(pcr_index, event_type, digest_list, size, event, log); event_log.pos += event_size; event_log.last_event_size = event_size; } if (!event_log.get_event_called) return ret; /* if GetEventLog has been called update FinalEventLog as well */ if (event_log.final_pos + event_size > TPM2_EVENT_LOG_SIZE) return EFI_VOLUME_FULL; log = (void *)((uintptr_t)event_log.final_buffer + event_log.final_pos); tcg2_log_append(pcr_index, event_type, digest_list, size, event, log); final_event = event_log.final_buffer; final_event->number_of_events++; event_log.final_pos += event_size; return ret; } /** * tpm2_get_max_command_size() - get the supported max command size * * @dev: TPM device * @max_command_size: output buffer for the size * * Return: 0 on success, -1 on error */ static int tpm2_get_max_command_size(struct udevice *dev, u16 *max_command_size) { u8 response[TPM2_RESPONSE_BUFFER_SIZE]; u32 ret; memset(response, 0, sizeof(response)); ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES, TPM2_PT_MAX_COMMAND_SIZE, response, 1); if (ret) return -1; *max_command_size = (uint16_t)get_unaligned_be32(response + properties_offset); return 0; } /** * tpm2_get_max_response_size() - get the supported max response size * * @dev: TPM device * @max_response_size: output buffer for the size * * Return: 0 on success, -1 on error */ static int tpm2_get_max_response_size(struct udevice *dev, u16 *max_response_size) { u8 response[TPM2_RESPONSE_BUFFER_SIZE]; u32 ret; memset(response, 0, sizeof(response)); ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES, TPM2_PT_MAX_RESPONSE_SIZE, response, 1); if (ret) return -1; *max_response_size = (uint16_t)get_unaligned_be32(response + properties_offset); return 0; } /** * tpm2_get_manufacturer_id() - get the manufacturer ID * * @dev: TPM device * @manufacturer_id: output buffer for the id * * Return: 0 on success, -1 on error */ static int tpm2_get_manufacturer_id(struct udevice *dev, u32 *manufacturer_id) { u8 response[TPM2_RESPONSE_BUFFER_SIZE]; u32 ret; memset(response, 0, sizeof(response)); ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES, TPM2_PT_MANUFACTURER, response, 1); if (ret) return -1; *manufacturer_id = get_unaligned_be32(response + properties_offset); return 0; } /** * efi_tcg2_get_capability() - protocol capability information and state information * * @this: TCG2 protocol instance * @capability: caller allocated memory with size field to the size of * the structure allocated * Return: status code */ static efi_status_t EFIAPI efi_tcg2_get_capability(struct efi_tcg2_protocol *this, struct efi_tcg2_boot_service_capability *capability) { struct udevice *dev; efi_status_t efi_ret; int ret; EFI_ENTRY("%p, %p", this, capability); if (!this || !capability) { efi_ret = EFI_INVALID_PARAMETER; goto out; } if (capability->size < BOOT_SERVICE_CAPABILITY_MIN) { capability->size = BOOT_SERVICE_CAPABILITY_MIN; efi_ret = EFI_BUFFER_TOO_SMALL; goto out; } if (capability->size < sizeof(*capability)) { capability->size = sizeof(*capability); efi_ret = EFI_BUFFER_TOO_SMALL; goto out; } capability->structure_version.major = 1; capability->structure_version.minor = 1; capability->protocol_version.major = 1; capability->protocol_version.minor = 1; efi_ret = tcg2_platform_get_tpm2(&dev); if (efi_ret != EFI_SUCCESS) { capability->supported_event_logs = 0; capability->hash_algorithm_bitmap = 0; capability->tpm_present_flag = false; capability->max_command_size = 0; capability->max_response_size = 0; capability->manufacturer_id = 0; capability->number_of_pcr_banks = 0; capability->active_pcr_banks = 0; efi_ret = EFI_SUCCESS; goto out; } /* We only allow a TPMv2 device to register the EFI protocol */ capability->supported_event_logs = TCG2_EVENT_LOG_FORMAT_TCG_2; capability->tpm_present_flag = true; /* Supported and active PCRs */ capability->hash_algorithm_bitmap = 0; capability->active_pcr_banks = 0; ret = tpm2_get_pcr_info(dev, &capability->hash_algorithm_bitmap, &capability->active_pcr_banks, &capability->number_of_pcr_banks); if (ret) { efi_ret = EFI_DEVICE_ERROR; goto out; } /* Max command size */ ret = tpm2_get_max_command_size(dev, &capability->max_command_size); if (ret) { efi_ret = EFI_DEVICE_ERROR; goto out; } /* Max response size */ ret = tpm2_get_max_response_size(dev, &capability->max_response_size); if (ret) { efi_ret = EFI_DEVICE_ERROR; goto out; } /* Manufacturer ID */ ret = tpm2_get_manufacturer_id(dev, &capability->manufacturer_id); if (ret) { efi_ret = EFI_DEVICE_ERROR; goto out; } return EFI_EXIT(EFI_SUCCESS); out: return EFI_EXIT(efi_ret); } /** * efi_tcg2_get_eventlog() - retrieve the the address of an event log and its * last entry * * @this: TCG2 protocol instance * @log_format: type of event log format * @event_log_location: pointer to the memory address of the event log * @event_log_last_entry: pointer to the address of the start of the last * entry in the event log in memory, if log contains * more than 1 entry * @event_log_truncated: set to true, if the Event Log is missing at i * least one entry * * Return: status code */ static efi_status_t EFIAPI efi_tcg2_get_eventlog(struct efi_tcg2_protocol *this, efi_tcg_event_log_format log_format, u64 *event_log_location, u64 *event_log_last_entry, bool *event_log_truncated) { efi_status_t ret = EFI_SUCCESS; struct udevice *dev; EFI_ENTRY("%p, %u, %p, %p, %p", this, log_format, event_log_location, event_log_last_entry, event_log_truncated); if (!this || !event_log_location || !event_log_last_entry || !event_log_truncated) { ret = EFI_INVALID_PARAMETER; goto out; } /* Only support TPMV2 */ if (log_format != TCG2_EVENT_LOG_FORMAT_TCG_2) { ret = EFI_INVALID_PARAMETER; goto out; } ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) { event_log_location = NULL; event_log_last_entry = NULL; *event_log_truncated = false; ret = EFI_SUCCESS; goto out; } *event_log_location = (uintptr_t)event_log.buffer; *event_log_last_entry = (uintptr_t)(event_log.buffer + event_log.pos - event_log.last_event_size); *event_log_truncated = event_log.truncated; event_log.get_event_called = true; out: return EFI_EXIT(ret); } /** * tcg2_hash_pe_image() - calculate PE/COFF image hash * * @efi: pointer to the EFI binary * @efi_size: size of @efi binary * @digest_list: list of digest algorithms to extend * * Return: status code */ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size, struct tpml_digest_values *digest_list) { WIN_CERTIFICATE *wincerts = NULL; size_t wincerts_len; struct efi_image_regions *regs = NULL; void *new_efi = NULL; u8 hash[TPM2_SHA512_DIGEST_SIZE]; struct udevice *dev; efi_status_t ret; u32 active; int i; new_efi = efi_prepare_aligned_image(efi, &efi_size); if (!new_efi) return EFI_OUT_OF_RESOURCES; if (!efi_image_parse(new_efi, efi_size, ®s, &wincerts, &wincerts_len)) { log_err("Parsing PE executable image failed\n"); ret = EFI_UNSUPPORTED; goto out; } ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) goto out; ret = tcg2_get_active_pcr_banks(dev, &active); if (ret != EFI_SUCCESS) { goto out; } digest_list->count = 0; for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); i++) { u16 hash_alg = tpm2_supported_algorithms[i]; if (!(active & tpm2_algorithm_to_mask(hash_alg))) continue; switch (hash_alg) { case TPM2_ALG_SHA1: hash_calculate("sha1", regs->reg, regs->num, hash); break; case TPM2_ALG_SHA256: hash_calculate("sha256", regs->reg, regs->num, hash); break; case TPM2_ALG_SHA384: hash_calculate("sha384", regs->reg, regs->num, hash); break; case TPM2_ALG_SHA512: hash_calculate("sha512", regs->reg, regs->num, hash); break; default: continue; } digest_list->digests[digest_list->count].hash_alg = hash_alg; memcpy(&digest_list->digests[digest_list->count].digest, hash, (u32)tpm2_algorithm_to_len(hash_alg)); digest_list->count++; } out: if (new_efi != efi) free(new_efi); free(regs); return ret; } /** * tcg2_measure_pe_image() - measure PE/COFF image * * @efi: pointer to the EFI binary * @efi_size: size of @efi binary * @handle: loaded image handle * @loaded_image: loaded image protocol * * Return: status code */ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size, struct efi_loaded_image_obj *handle, struct efi_loaded_image *loaded_image) { struct tpml_digest_values digest_list; efi_status_t ret; struct udevice *dev; u32 pcr_index, event_type, event_size; struct uefi_image_load_event *image_load_event; struct efi_device_path *device_path; u32 device_path_length; IMAGE_DOS_HEADER *dos; IMAGE_NT_HEADERS32 *nt; struct efi_handler *handler; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) return EFI_SECURITY_VIOLATION; switch (handle->image_type) { case IMAGE_SUBSYSTEM_EFI_APPLICATION: pcr_index = 4; event_type = EV_EFI_BOOT_SERVICES_APPLICATION; break; case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER: pcr_index = 2; event_type = EV_EFI_BOOT_SERVICES_DRIVER; break; case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER: pcr_index = 2; event_type = EV_EFI_RUNTIME_SERVICES_DRIVER; break; default: return EFI_UNSUPPORTED; } ret = tcg2_hash_pe_image(efi, efi_size, &digest_list); if (ret != EFI_SUCCESS) return ret; ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); if (ret != EFI_SUCCESS) return ret; ret = efi_search_protocol(&handle->header, &efi_guid_loaded_image_device_path, &handler); if (ret != EFI_SUCCESS) return ret; device_path = handler->protocol_interface; device_path_length = efi_dp_size(device_path); if (device_path_length > 0) { /* add end node size */ device_path_length += sizeof(struct efi_device_path); } event_size = sizeof(struct uefi_image_load_event) + device_path_length; image_load_event = calloc(1, event_size); if (!image_load_event) return EFI_OUT_OF_RESOURCES; image_load_event->image_location_in_memory = (uintptr_t)efi; image_load_event->image_length_in_memory = efi_size; image_load_event->length_of_device_path = device_path_length; dos = (IMAGE_DOS_HEADER *)efi; nt = (IMAGE_NT_HEADERS32 *)(efi + dos->e_lfanew); if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) { IMAGE_NT_HEADERS64 *nt64 = (IMAGE_NT_HEADERS64 *)nt; image_load_event->image_link_time_address = nt64->OptionalHeader.ImageBase; } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) { image_load_event->image_link_time_address = nt->OptionalHeader.ImageBase; } else { ret = EFI_INVALID_PARAMETER; goto out; } /* device_path_length might be zero */ memcpy(image_load_event->device_path, device_path, device_path_length); ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list, event_size, (u8 *)image_load_event); out: free(image_load_event); return ret; } /** * efi_tcg2_hash_log_extend_event() - extend and optionally log events * * @this: TCG2 protocol instance * @flags: bitmap providing additional information on the * operation * @data_to_hash: physical address of the start of the data buffer * to be hashed * @data_to_hash_len: the length in bytes of the buffer referenced by * data_to_hash * @efi_tcg_event: pointer to data buffer containing information * about the event * * Return: status code */ static efi_status_t EFIAPI efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags, u64 data_to_hash, u64 data_to_hash_len, struct efi_tcg2_event *efi_tcg_event) { struct udevice *dev; efi_status_t ret; u32 event_type, pcr_index, event_size; struct tpml_digest_values digest_list; EFI_ENTRY("%p, %llu, %llu, %llu, %p", this, flags, data_to_hash, data_to_hash_len, efi_tcg_event); if (!this || !data_to_hash || !efi_tcg_event) { ret = EFI_INVALID_PARAMETER; goto out; } ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) goto out; if (efi_tcg_event->size < efi_tcg_event->header.header_size + sizeof(u32)) { ret = EFI_INVALID_PARAMETER; goto out; } if (efi_tcg_event->header.pcr_index > EFI_TCG2_MAX_PCR_INDEX) { ret = EFI_INVALID_PARAMETER; goto out; } /* * if PE_COFF_IMAGE is set we need to make sure the image is not * corrupted, verify it and hash the PE/COFF image in accordance with * the procedure specified in "Calculating the PE Image Hash" * section of the "Windows Authenticode Portable Executable Signature * Format" */ if (flags & PE_COFF_IMAGE) { IMAGE_NT_HEADERS32 *nt; ret = efi_check_pe((void *)(uintptr_t)data_to_hash, data_to_hash_len, (void **)&nt); if (ret != EFI_SUCCESS) { log_err("Not a valid PE-COFF file\n"); ret = EFI_UNSUPPORTED; goto out; } ret = tcg2_hash_pe_image((void *)(uintptr_t)data_to_hash, data_to_hash_len, &digest_list); } else { ret = tcg2_create_digest(dev, (u8 *)(uintptr_t)data_to_hash, data_to_hash_len, &digest_list); } if (ret != EFI_SUCCESS) goto out; pcr_index = efi_tcg_event->header.pcr_index; event_type = efi_tcg_event->header.event_type; ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); if (ret != EFI_SUCCESS) goto out; if (flags & EFI_TCG2_EXTEND_ONLY) { if (event_log.truncated) ret = EFI_VOLUME_FULL; goto out; } /* * The efi_tcg_event size includes the size component and the * headersize */ event_size = efi_tcg_event->size - sizeof(efi_tcg_event->size) - efi_tcg_event->header.header_size; ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list, event_size, efi_tcg_event->event); out: return EFI_EXIT(ret); } /** * efi_tcg2_submit_command() - Send command to the TPM * * @this: TCG2 protocol instance * @input_param_block_size: size of the TPM input parameter block * @input_param_block: pointer to the TPM input parameter block * @output_param_block_size: size of the TPM output parameter block * @output_param_block: pointer to the TPM output parameter block * * Return: status code */ static efi_status_t EFIAPI efi_tcg2_submit_command(struct efi_tcg2_protocol *this, u32 input_param_block_size, u8 *input_param_block, u32 output_param_block_size, u8 *output_param_block) { struct udevice *dev; efi_status_t ret; u32 rc; size_t resp_buf_size = output_param_block_size; EFI_ENTRY("%p, %u, %p, %u, %p", this, input_param_block_size, input_param_block, output_param_block_size, output_param_block); if (!this || !input_param_block || !input_param_block_size) { ret = EFI_INVALID_PARAMETER; goto out; } ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) goto out; rc = tpm2_submit_command(dev, input_param_block, output_param_block, &resp_buf_size); if (rc) { ret = (rc == -ENOSPC) ? EFI_OUT_OF_RESOURCES : EFI_DEVICE_ERROR; goto out; } out: return EFI_EXIT(ret); } /** * efi_tcg2_get_active_pcr_banks() - returns the currently active PCR banks * * @this: TCG2 protocol instance * @active_pcr_banks: pointer for receiving the bitmap of currently * active PCR banks * * Return: status code */ static efi_status_t EFIAPI efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this, u32 *active_pcr_banks) { struct udevice *dev; efi_status_t ret; EFI_ENTRY("%p, %p", this, active_pcr_banks); if (!this || !active_pcr_banks) { ret = EFI_INVALID_PARAMETER; goto out; } ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) goto out; ret = tcg2_get_active_pcr_banks(dev, active_pcr_banks); out: return EFI_EXIT(ret); } /** * efi_tcg2_set_active_pcr_banks() - sets the currently active PCR banks * * @this: TCG2 protocol instance * @active_pcr_banks: bitmap of the requested active PCR banks * * Return: status code */ static efi_status_t EFIAPI efi_tcg2_set_active_pcr_banks(__maybe_unused struct efi_tcg2_protocol *this, u32 __maybe_unused active_pcr_banks) { return EFI_UNSUPPORTED; } /** * efi_tcg2_get_result_of_set_active_pcr_banks() - retrieve result for previous * set_active_pcr_banks() * * @this: TCG2 protocol instance * @operation_present: non-zero value to indicate a * set_active_pcr_banks operation was * invoked during last boot * @response: result value could be returned * * Return: status code */ static efi_status_t EFIAPI efi_tcg2_get_result_of_set_active_pcr_banks(__maybe_unused struct efi_tcg2_protocol *this, u32 __maybe_unused *operation_present, u32 __maybe_unused *response) { return EFI_UNSUPPORTED; } static const struct efi_tcg2_protocol efi_tcg2_protocol = { .get_capability = efi_tcg2_get_capability, .get_eventlog = efi_tcg2_get_eventlog, .hash_log_extend_event = efi_tcg2_hash_log_extend_event, .submit_command = efi_tcg2_submit_command, .get_active_pcr_banks = efi_tcg2_get_active_pcr_banks, .set_active_pcr_banks = efi_tcg2_set_active_pcr_banks, .get_result_of_set_active_pcr_banks = efi_tcg2_get_result_of_set_active_pcr_banks, }; /** * tcg2_uninit - remove the final event table and free efi memory on failures */ void tcg2_uninit(void) { efi_status_t ret; ret = efi_install_configuration_table(&efi_guid_final_events, NULL); if (ret != EFI_SUCCESS) log_err("Failed to delete final events config table\n"); efi_free_pool(event_log.buffer); event_log.buffer = NULL; efi_free_pool(event_log.final_buffer); event_log.final_buffer = NULL; if (!is_tcg2_protocol_installed()) return; ret = efi_uninstall_multiple_protocol_interfaces(efi_root, &efi_guid_tcg2_protocol, &efi_tcg2_protocol, NULL); if (ret != EFI_SUCCESS) log_err("Failed to remove EFI TCG2 protocol\n"); } /** * create_final_event() - Create the final event and install the config * defined by the TCG EFI spec */ static efi_status_t create_final_event(void) { struct efi_tcg2_final_events_table *final_event; efi_status_t ret; /* * All events generated after the invocation of * EFI_TCG2_GET_EVENT_LOGS need to be stored in an instance of an * EFI_CONFIGURATION_TABLE */ ret = efi_allocate_pool(EFI_ACPI_MEMORY_NVS, TPM2_EVENT_LOG_SIZE, &event_log.final_buffer); if (ret != EFI_SUCCESS) goto out; memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE); final_event = event_log.final_buffer; final_event->number_of_events = 0; final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION; event_log.final_pos = sizeof(*final_event); ret = efi_install_configuration_table(&efi_guid_final_events, final_event); if (ret != EFI_SUCCESS) { efi_free_pool(event_log.final_buffer); event_log.final_buffer = NULL; } out: return ret; } /** * measure_event() - common function to add event log and extend PCR * * @dev: TPM device * @pcr_index: PCR index * @event_type: type of event added * @size: event size * @event: event data * * Return: status code */ static efi_status_t measure_event(struct udevice *dev, u32 pcr_index, u32 event_type, u32 size, u8 event[]) { struct tpml_digest_values digest_list; efi_status_t ret; ret = tcg2_create_digest(dev, event, size, &digest_list); if (ret != EFI_SUCCESS) goto out; ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); if (ret != EFI_SUCCESS) goto out; ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list, size, event); out: return ret; } /** * efi_append_scrtm_version - Append an S-CRTM EV_S_CRTM_VERSION event on the * eventlog and extend the PCRs * * @dev: TPM device * * @Return: status code */ static efi_status_t efi_append_scrtm_version(struct udevice *dev) { efi_status_t ret; ret = measure_event(dev, 0, EV_S_CRTM_VERSION, strlen(version_string) + 1, (u8 *)version_string); return ret; } /** * efi_init_event_log() - initialize an eventlog * * Return: status code */ static efi_status_t efi_init_event_log(void) { /* * vendor_info_size is currently set to 0, we need to change the length * and allocate the flexible array member if this changes */ struct tcg2_event_log elog; struct udevice *dev; efi_status_t ret; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) return ret; ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, TPM2_EVENT_LOG_SIZE, (void **)&event_log.buffer); if (ret != EFI_SUCCESS) return ret; /* * initialize log area as 0xff so the OS can easily figure out the * last log entry */ memset(event_log.buffer, 0xff, TPM2_EVENT_LOG_SIZE); /* * The log header is defined to be in SHA1 event log entry format. * Setup event header */ event_log.pos = 0; event_log.last_event_size = 0; event_log.get_event_called = false; event_log.ebs_called = false; event_log.truncated = false; /* * Check if earlier firmware have passed any eventlog. Different * platforms can use different ways to do so. */ elog.log = event_log.buffer; elog.log_size = TPM2_EVENT_LOG_SIZE; ret = tcg2_log_prepare_buffer(dev, &elog, false); if (ret != EFI_SUCCESS) goto free_pool; event_log.pos = elog.log_position; /* * Add SCRTM version to the log if previous firmmware * doesn't pass an eventlog. */ if (!elog.found) { ret = efi_append_scrtm_version(dev); if (ret != EFI_SUCCESS) goto free_pool; } ret = create_final_event(); if (ret != EFI_SUCCESS) goto free_pool; return ret; free_pool: efi_free_pool(event_log.buffer); event_log.buffer = NULL; return ret; } /** * tcg2_measure_variable() - add variable event log and extend PCR * * @dev: TPM device * @pcr_index: PCR index * @event_type: type of event added * @var_name: variable name * @guid: guid * @data_size: variable data size * @data: variable data * * Return: status code */ static efi_status_t tcg2_measure_variable(struct udevice *dev, u32 pcr_index, u32 event_type, const u16 *var_name, const efi_guid_t *guid, efi_uintn_t data_size, u8 *data) { u32 event_size; efi_status_t ret; struct efi_tcg2_uefi_variable_data *event; event_size = sizeof(event->variable_name) + sizeof(event->unicode_name_length) + sizeof(event->variable_data_length) + (u16_strlen(var_name) * sizeof(u16)) + data_size; event = malloc(event_size); if (!event) return EFI_OUT_OF_RESOURCES; guidcpy(&event->variable_name, guid); event->unicode_name_length = u16_strlen(var_name); event->variable_data_length = data_size; memcpy(event->unicode_name, var_name, (event->unicode_name_length * sizeof(u16))); if (data) { memcpy((u16 *)event->unicode_name + event->unicode_name_length, data, data_size); } ret = measure_event(dev, pcr_index, event_type, event_size, (u8 *)event); free(event); return ret; } /** * tcg2_measure_boot_variable() - measure boot variables * * @dev: TPM device * * Return: status code */ static efi_status_t tcg2_measure_boot_variable(struct udevice *dev) { u16 *boot_order; u16 *boot_index; u16 var_name[] = u"BootOrder"; u16 boot_name[] = u"Boot####"; u8 *bootvar; efi_uintn_t var_data_size; u32 count, i; efi_status_t ret; boot_order = efi_get_var(var_name, &efi_global_variable_guid, &var_data_size); if (!boot_order) { /* If "BootOrder" is not defined, skip the boot variable measurement */ return EFI_SUCCESS; } ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2, var_name, &efi_global_variable_guid, var_data_size, (u8 *)boot_order); if (ret != EFI_SUCCESS) goto error; count = var_data_size / sizeof(*boot_order); boot_index = boot_order; for (i = 0; i < count; i++) { efi_create_indexed_name(boot_name, sizeof(boot_name), "Boot", *boot_index++); bootvar = efi_get_var(boot_name, &efi_global_variable_guid, &var_data_size); if (!bootvar) { log_debug("%ls not found\n", boot_name); continue; } ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2, boot_name, &efi_global_variable_guid, var_data_size, bootvar); free(bootvar); if (ret != EFI_SUCCESS) goto error; } error: free(boot_order); return ret; } /** * tcg2_measure_smbios() - measure smbios table * * @dev: TPM device * @entry: pointer to the smbios_entry structure * * Return: status code */ static efi_status_t tcg2_measure_smbios(struct udevice *dev, const struct smbios3_entry *entry) { efi_status_t ret; struct smbios_header *smbios_copy; struct smbios_handoff_table_pointers2 *event = NULL; u32 event_size; const char smbios3_anchor[] = "_SM3_"; /* We only support SMBIOS 3.0 Entry Point structure */ if (memcmp(entry->anchor, smbios3_anchor, sizeof(smbios3_anchor) - 1)) return EFI_UNSUPPORTED; /* * TCG PC Client PFP Spec says * "SMBIOS structures that contain static configuration information * (e.g. Platform Manufacturer Enterprise Number assigned by IANA, * platform model number, Vendor and Device IDs for each SMBIOS table) * that is relevant to the security of the platform MUST be measured". * Device dependent parameters such as serial number are cleared to * zero or spaces for the measurement. */ event_size = sizeof(struct smbios_handoff_table_pointers2) + FIELD_SIZEOF(struct efi_configuration_table, guid) + entry->table_maximum_size; event = calloc(1, event_size); if (!event) { ret = EFI_OUT_OF_RESOURCES; goto out; } event->table_description_size = sizeof(SMBIOS_HANDOFF_TABLE_DESC); memcpy(event->table_description, SMBIOS_HANDOFF_TABLE_DESC, sizeof(SMBIOS_HANDOFF_TABLE_DESC)); put_unaligned_le64(1, &event->number_of_tables); guidcpy(&event->table_entry[0].guid, &smbios3_guid); smbios_copy = (struct smbios_header *)((uintptr_t)&event->table_entry[0].table); memcpy(&event->table_entry[0].table, (void *)((uintptr_t)entry->struct_table_address), entry->table_maximum_size); smbios_prepare_measurement(entry, smbios_copy); ret = measure_event(dev, 1, EV_EFI_HANDOFF_TABLES2, event_size, (u8 *)event); if (ret != EFI_SUCCESS) goto out; out: free(event); return ret; } /** * tcg2_measure_gpt_table() - measure gpt table * * @dev: TPM device * @loaded_image: handle to the loaded image * * Return: status code */ static efi_status_t tcg2_measure_gpt_data(struct udevice *dev, struct efi_loaded_image_obj *loaded_image) { efi_status_t ret; efi_handle_t handle; struct efi_handler *dp_handler, *io_handler; struct efi_device_path *orig_device_path; struct efi_device_path *device_path; struct efi_device_path *dp; struct efi_block_io *block_io; struct efi_gpt_data *event = NULL; efi_guid_t null_guid = NULL_GUID; gpt_header *gpt_h; gpt_entry *entry = NULL; gpt_entry *gpt_e; u32 num_of_valid_entry = 0; u32 event_size; u32 i; u32 total_gpt_entry_size; ret = efi_search_protocol(&loaded_image->header, &efi_guid_loaded_image_device_path, &dp_handler); if (ret != EFI_SUCCESS) return ret; orig_device_path = dp_handler->protocol_interface; if (!orig_device_path) /* no device path, skip GPT measurement */ return EFI_SUCCESS; device_path = efi_dp_dup(orig_device_path); if (!device_path) return EFI_OUT_OF_RESOURCES; dp = search_gpt_dp_node(device_path); if (!dp) { /* no GPT device path node found, skip GPT measurement */ ret = EFI_SUCCESS; goto out1; } /* read GPT header */ dp->type = DEVICE_PATH_TYPE_END; dp->sub_type = DEVICE_PATH_SUB_TYPE_END; dp = device_path; ret = EFI_CALL(systab.boottime->locate_device_path(&efi_block_io_guid, &dp, &handle)); if (ret != EFI_SUCCESS) goto out1; ret = efi_search_protocol(handle, &efi_block_io_guid, &io_handler); if (ret != EFI_SUCCESS) goto out1; block_io = io_handler->protocol_interface; gpt_h = memalign(block_io->media->io_align, block_io->media->block_size); if (!gpt_h) { ret = EFI_OUT_OF_RESOURCES; goto out2; } ret = block_io->read_blocks(block_io, block_io->media->media_id, 1, block_io->media->block_size, gpt_h); if (ret != EFI_SUCCESS) goto out2; /* read GPT entry */ total_gpt_entry_size = gpt_h->num_partition_entries * gpt_h->sizeof_partition_entry; entry = memalign(block_io->media->io_align, total_gpt_entry_size); if (!entry) { ret = EFI_OUT_OF_RESOURCES; goto out2; } ret = block_io->read_blocks(block_io, block_io->media->media_id, gpt_h->partition_entry_lba, total_gpt_entry_size, entry); if (ret != EFI_SUCCESS) goto out2; /* count valid GPT entry */ gpt_e = entry; for (i = 0; i < gpt_h->num_partition_entries; i++) { if (guidcmp(&null_guid, &gpt_e->partition_type_guid)) num_of_valid_entry++; gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry); } /* prepare event data for measurement */ event_size = sizeof(struct efi_gpt_data) + (num_of_valid_entry * gpt_h->sizeof_partition_entry); event = calloc(1, event_size); if (!event) { ret = EFI_OUT_OF_RESOURCES; goto out2; } memcpy(event, gpt_h, sizeof(gpt_header)); put_unaligned_le64(num_of_valid_entry, &event->number_of_partitions); /* copy valid GPT entry */ gpt_e = entry; num_of_valid_entry = 0; for (i = 0; i < gpt_h->num_partition_entries; i++) { if (guidcmp(&null_guid, &gpt_e->partition_type_guid)) { memcpy((u8 *)event->partitions + (num_of_valid_entry * gpt_h->sizeof_partition_entry), gpt_e, gpt_h->sizeof_partition_entry); num_of_valid_entry++; } gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry); } ret = measure_event(dev, 5, EV_EFI_GPT_EVENT, event_size, (u8 *)event); out2: free(gpt_h); free(entry); free(event); out1: efi_free_pool(device_path); return ret; } /* Return the byte size of reserved map area in DTB or -1 upon error */ static ssize_t size_of_rsvmap(void *dtb) { struct fdt_reserve_entry e; ssize_t size_max; ssize_t size; u8 *rsvmap_base; rsvmap_base = (u8 *)dtb + fdt_off_mem_rsvmap(dtb); size_max = fdt_totalsize(dtb) - fdt_off_mem_rsvmap(dtb); size = 0; do { memcpy(&e, rsvmap_base + size, sizeof(e)); size += sizeof(e); if (size > size_max) return -1; } while (e.size); return size; } /** * efi_tcg2_measure_dtb() - measure DTB passed to the OS * * @dtb: pointer to the device tree blob * * Return: status code */ efi_status_t efi_tcg2_measure_dtb(void *dtb) { struct uefi_platform_firmware_blob2 *blob; struct fdt_header *header; sha256_context hash_ctx; struct udevice *dev; ssize_t rsvmap_size; efi_status_t ret; u32 event_size; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) return EFI_SECURITY_VIOLATION; rsvmap_size = size_of_rsvmap(dtb); if (rsvmap_size < 0) return EFI_SECURITY_VIOLATION; event_size = sizeof(*blob) + sizeof(EFI_DTB_EVENT_STRING) + SHA256_SUM_LEN; blob = calloc(1, event_size); if (!blob) return EFI_OUT_OF_RESOURCES; blob->blob_description_size = sizeof(EFI_DTB_EVENT_STRING); memcpy(blob->data, EFI_DTB_EVENT_STRING, blob->blob_description_size); /* Measure populated areas of the DTB */ header = dtb; sha256_starts(&hash_ctx); sha256_update(&hash_ctx, (u8 *)header, sizeof(struct fdt_header)); sha256_update(&hash_ctx, (u8 *)dtb + fdt_off_dt_struct(dtb), fdt_size_dt_strings(dtb)); sha256_update(&hash_ctx, (u8 *)dtb + fdt_off_dt_strings(dtb), fdt_size_dt_struct(dtb)); sha256_update(&hash_ctx, (u8 *)dtb + fdt_off_mem_rsvmap(dtb), rsvmap_size); sha256_finish(&hash_ctx, blob->data + blob->blob_description_size); ret = measure_event(dev, 0, EV_POST_CODE, event_size, (u8 *)blob); free(blob); return ret; } /** * efi_tcg2_measure_efi_app_invocation() - measure efi app invocation * * Return: status code */ efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *handle) { efi_status_t ret; u32 pcr_index; struct udevice *dev; u32 event = 0; struct smbios3_entry *entry; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; if (tcg2_efi_app_invoked) return EFI_SUCCESS; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) return EFI_SECURITY_VIOLATION; ret = tcg2_measure_boot_variable(dev); if (ret != EFI_SUCCESS) goto out; ret = measure_event(dev, 4, EV_EFI_ACTION, strlen(EFI_CALLING_EFI_APPLICATION), (u8 *)EFI_CALLING_EFI_APPLICATION); if (ret != EFI_SUCCESS) goto out; entry = efi_get_configuration_table(&smbios3_guid); if (entry) { ret = tcg2_measure_smbios(dev, entry); if (ret != EFI_SUCCESS) goto out; } ret = tcg2_measure_gpt_data(dev, handle); if (ret != EFI_SUCCESS) goto out; for (pcr_index = 0; pcr_index <= 7; pcr_index++) { ret = measure_event(dev, pcr_index, EV_SEPARATOR, sizeof(event), (u8 *)&event); if (ret != EFI_SUCCESS) goto out; } tcg2_efi_app_invoked = true; out: return ret; } /** * efi_tcg2_measure_efi_app_exit() - measure efi app exit * * Return: status code */ efi_status_t efi_tcg2_measure_efi_app_exit(void) { efi_status_t ret; struct udevice *dev; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) return ret; ret = measure_event(dev, 4, EV_EFI_ACTION, strlen(EFI_RETURNING_FROM_EFI_APPLICATION), (u8 *)EFI_RETURNING_FROM_EFI_APPLICATION); return ret; } /** * efi_tcg2_notify_exit_boot_services() - ExitBootService callback * * @event: callback event * @context: callback context */ static void EFIAPI efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context) { efi_status_t ret; struct udevice *dev; EFI_ENTRY("%p, %p", event, context); event_log.ebs_called = true; if (!is_tcg2_protocol_installed()) { ret = EFI_SUCCESS; goto out; } ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) goto out; ret = measure_event(dev, 5, EV_EFI_ACTION, strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION), (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION); if (ret != EFI_SUCCESS) goto out; ret = measure_event(dev, 5, EV_EFI_ACTION, strlen(EFI_EXIT_BOOT_SERVICES_SUCCEEDED), (u8 *)EFI_EXIT_BOOT_SERVICES_SUCCEEDED); out: EFI_EXIT(ret); } /** * efi_tcg2_notify_exit_boot_services_failed() * - notify ExitBootServices() is failed * * Return: status code */ efi_status_t efi_tcg2_notify_exit_boot_services_failed(void) { struct udevice *dev; efi_status_t ret; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) goto out; ret = measure_event(dev, 5, EV_EFI_ACTION, strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION), (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION); if (ret != EFI_SUCCESS) goto out; ret = measure_event(dev, 5, EV_EFI_ACTION, strlen(EFI_EXIT_BOOT_SERVICES_FAILED), (u8 *)EFI_EXIT_BOOT_SERVICES_FAILED); out: return ret; } /** * tcg2_measure_secure_boot_variable() - measure secure boot variables * * @dev: TPM device * * Return: status code */ static efi_status_t tcg2_measure_secure_boot_variable(struct udevice *dev) { u8 *data; efi_uintn_t data_size; u32 count, i; efi_status_t ret; u8 deployed_mode; efi_uintn_t size; u32 deployed_audit_pcr_index = 1; size = sizeof(deployed_mode); ret = efi_get_variable_int(u"DeployedMode", &efi_global_variable_guid, NULL, &size, &deployed_mode, NULL); if (ret != EFI_SUCCESS || !deployed_mode) deployed_audit_pcr_index = 7; count = ARRAY_SIZE(secure_variables); for (i = 0; i < count; i++) { const efi_guid_t *guid; guid = efi_auth_var_get_guid(secure_variables[i].name); data = efi_get_var(secure_variables[i].name, guid, &data_size); if (!data && !secure_variables[i].accept_empty) continue; if (u16_strcmp(u"DeployedMode", secure_variables[i].name)) secure_variables[i].pcr_index = deployed_audit_pcr_index; if (u16_strcmp(u"AuditMode", secure_variables[i].name)) secure_variables[i].pcr_index = deployed_audit_pcr_index; ret = tcg2_measure_variable(dev, secure_variables[i].pcr_index, EV_EFI_VARIABLE_DRIVER_CONFIG, secure_variables[i].name, guid, data_size, data); free(data); if (ret != EFI_SUCCESS) goto error; } error: return ret; } /** * efi_tcg2_do_initial_measurement() - do initial measurement * * Return: status code */ efi_status_t efi_tcg2_do_initial_measurement(void) { efi_status_t ret; struct udevice *dev; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) return EFI_SECURITY_VIOLATION; ret = tcg2_measure_secure_boot_variable(dev); if (ret != EFI_SUCCESS) goto out; out: return ret; } /** * efi_tcg2_register() - register EFI_TCG2_PROTOCOL * * If a TPM2 device is available, the TPM TCG2 Protocol is registered * * Return: status code */ efi_status_t efi_tcg2_register(void) { efi_status_t ret = EFI_SUCCESS; struct udevice *dev; struct efi_event *event; u32 err; ret = tcg2_platform_get_tpm2(&dev); if (ret != EFI_SUCCESS) { log_warning("Missing TPMv2 device for EFI_TCG_PROTOCOL\n"); return EFI_SUCCESS; } /* initialize the TPM as early as possible. */ err = tpm_auto_start(dev); if (err) { log_err("TPM startup failed\n"); goto fail; } ret = efi_init_event_log(); if (ret != EFI_SUCCESS) { tcg2_uninit(); goto fail; } ret = efi_install_multiple_protocol_interfaces(&efi_root, &efi_guid_tcg2_protocol, &efi_tcg2_protocol, NULL); if (ret != EFI_SUCCESS) { tcg2_uninit(); goto fail; } ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK, efi_tcg2_notify_exit_boot_services, NULL, NULL, &event); if (ret != EFI_SUCCESS) { tcg2_uninit(); goto fail; } return ret; fail: log_err("Cannot install EFI_TCG2_PROTOCOL\n"); return ret; }