// 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 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 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 digest_info { u16 hash_alg; u32 hash_mask; u16 hash_len; }; static const struct digest_info hash_algo_list[] = { { TPM2_ALG_SHA1, EFI_TCG2_BOOT_HASH_ALG_SHA1, TPM2_SHA1_DIGEST_SIZE, }, { TPM2_ALG_SHA256, EFI_TCG2_BOOT_HASH_ALG_SHA256, TPM2_SHA256_DIGEST_SIZE, }, { TPM2_ALG_SHA384, EFI_TCG2_BOOT_HASH_ALG_SHA384, TPM2_SHA384_DIGEST_SIZE, }, { TPM2_ALG_SHA512, EFI_TCG2_BOOT_HASH_ALG_SHA512, TPM2_SHA512_DIGEST_SIZE, }, }; static const u16 *secure_variables[] = { u"SecureBoot", u"PK", u"KEK", u"db", u"dbx", }; #define MAX_HASH_COUNT ARRAY_SIZE(hash_algo_list) /** * alg_to_mask - Get a TCG hash mask for algorithms * * @hash_alg: TCG defined algorithm * * @Return: TCG hashing algorithm bitmaps, 0 if the algorithm is not supported */ static u32 alg_to_mask(u16 hash_alg) { size_t i; for (i = 0; i < MAX_HASH_COUNT; i++) { if (hash_algo_list[i].hash_alg == hash_alg) return hash_algo_list[i].hash_mask; } return 0; } /** * alg_to_len - Get a TCG hash len for algorithms * * @hash_alg: TCG defined algorithm * * @Return: len of chosen algorithm, 0 if the algorithm is not supported */ static u16 alg_to_len(u16 hash_alg) { size_t i; for (i = 0; i < MAX_HASH_COUNT; i++) { if (hash_algo_list[i].hash_alg == hash_alg) return hash_algo_list[i].hash_len; } return 0; } static u32 tcg_event_final_size(struct tpml_digest_values *digest_list) { u32 len; size_t i; len = offsetof(struct tcg_pcr_event2, digests); len += offsetof(struct tpml_digest_values, digests); for (i = 0; i < digest_list->count; i++) { u16 hash_alg = digest_list->digests[i].hash_alg; len += offsetof(struct tpmt_ha, digest); len += alg_to_len(hash_alg); } len += sizeof(u32); /* tcg_pcr_event2 event_size*/ return len; } /* tcg2_pcr_extend - Extend PCRs for a TPM2 device for a given tpml_digest_values * * @dev: device * @digest_list: list of digest algorithms to extend * * @Return: status code */ static efi_status_t tcg2_pcr_extend(struct udevice *dev, u32 pcr_index, struct tpml_digest_values *digest_list) { u32 rc; size_t i; for (i = 0; i < digest_list->count; i++) { u32 alg = digest_list->digests[i].hash_alg; rc = tpm2_pcr_extend(dev, pcr_index, alg, (u8 *)&digest_list->digests[i].digest, alg_to_len(alg)); if (rc) { EFI_PRINT("Failed to extend PCR\n"); return EFI_DEVICE_ERROR; } } return EFI_SUCCESS; } /* tcg2_agile_log_append - Append an agile event to out 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 * * @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); size_t pos; size_t i; u32 event_size; if (event_log.get_event_called) log = (void *)((uintptr_t)event_log.final_buffer + event_log.final_pos); /* * size refers to the length of event[] only, we need to check against * the final tcg_pcr_event2 size */ event_size = size + tcg_event_final_size(digest_list); if (event_log.pos + event_size > TPM2_EVENT_LOG_SIZE || event_log.final_pos + event_size > TPM2_EVENT_LOG_SIZE) { event_log.truncated = true; return EFI_VOLUME_FULL; } put_unaligned_le32(pcr_index, log); pos = offsetof(struct tcg_pcr_event2, event_type); put_unaligned_le32(event_type, (void *)((uintptr_t)log + pos)); pos = offsetof(struct tcg_pcr_event2, digests); /* count */ put_unaligned_le32(digest_list->count, (void *)((uintptr_t)log + pos)); pos += offsetof(struct tpml_digest_values, digests); for (i = 0; i < digest_list->count; i++) { u16 hash_alg = digest_list->digests[i].hash_alg; u8 *digest = (u8 *)&digest_list->digests[i].digest; put_unaligned_le16(hash_alg, (void *)((uintptr_t)log + pos)); pos += offsetof(struct tpmt_ha, digest); memcpy((void *)((uintptr_t)log + pos), digest, alg_to_len(hash_alg)); pos += alg_to_len(hash_alg); } put_unaligned_le32(size, (void *)((uintptr_t)log + pos)); pos += sizeof(u32); /* tcg_pcr_event2 event_size*/ memcpy((void *)((uintptr_t)log + pos), event, size); pos += size; /* make sure the calculated buffer is what we checked against */ if (pos != event_size) return EFI_INVALID_PARAMETER; /* if GetEventLog hasn't been called update the normal log */ if (!event_log.get_event_called) { event_log.pos += pos; event_log.last_event_size = pos; } else { /* if GetEventLog has been called update config table log */ struct efi_tcg2_final_events_table *final_event; final_event = (struct efi_tcg2_final_events_table *)(event_log.final_buffer); final_event->number_of_events++; event_log.final_pos += pos; } return EFI_SUCCESS; } /** * platform_get_tpm_device() - retrieve TPM device * * This function retrieves the udevice implementing a TPM * * This function may be overridden if special initialization is needed. * * @dev: udevice * Return: status code */ __weak efi_status_t platform_get_tpm2_device(struct udevice **dev) { for_each_tpm_device(*dev) { /* Only support TPMv2 devices */ if (tpm_get_version(*dev) == TPM_V2) return EFI_SUCCESS; } return EFI_NOT_FOUND; } /** * 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; } /** * tpm2_get_num_pcr() - get the number of PCRs * * @dev: TPM device * @manufacturer_id: output buffer for the number * * Return: 0 on success, -1 on error */ static int tpm2_get_num_pcr(struct udevice *dev, u32 *num_pcr) { u8 response[TPM2_RESPONSE_BUFFER_SIZE]; u32 ret; memset(response, 0, sizeof(response)); ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES, TPM2_PT_PCR_COUNT, response, 1); if (ret) return -1; *num_pcr = get_unaligned_be32(response + properties_offset); if (*num_pcr > TPM2_MAX_PCRS) return -1; return 0; } /** * is_active_pcr() - Check if a supported algorithm is active * * @dev: TPM device * @selection: struct of PCR information * * Return: true if PCR is active */ static bool is_active_pcr(struct tpms_pcr_selection *selection) { int i; /* * check the pcr_select. If at least one of the PCRs supports the * algorithm add it on the active ones */ for (i = 0; i < selection->size_of_select; i++) { if (selection->pcr_select[i]) return true; } return false; } /** * tpm2_get_pcr_info() - get the supported, active PCRs and number of banks * * @dev: TPM device * @supported_pcr: bitmask with the algorithms supported * @active_pcr: bitmask with the active algorithms * @pcr_banks: number of PCR banks * * Return: 0 on success, -1 on error */ static int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, u32 *pcr_banks) { u8 response[TPM2_RESPONSE_BUFFER_SIZE]; struct tpml_pcr_selection pcrs; u32 ret, num_pcr; size_t i; int tpm_ret; *supported_pcr = 0; *active_pcr = 0; *pcr_banks = 0; memset(response, 0, sizeof(response)); ret = tpm2_get_capability(dev, TPM2_CAP_PCRS, 0, response, 1); if (ret) goto out; pcrs.count = get_unaligned_be32(response); /* * We only support 5 algorithms for now so check against that * instead of TPM2_NUM_PCR_BANKS */ if (pcrs.count > MAX_HASH_COUNT || pcrs.count < 1) goto out; tpm_ret = tpm2_get_num_pcr(dev, &num_pcr); if (tpm_ret) goto out; for (i = 0; i < pcrs.count; i++) { /* * Definition of TPMS_PCR_SELECTION Structure * hash: u16 * size_of_select: u8 * pcr_select: u8 array * * The offsets depend on the number of the device PCRs * so we have to calculate them based on that */ u32 hash_offset = offsetof(struct tpml_pcr_selection, selection) + i * offsetof(struct tpms_pcr_selection, pcr_select) + i * ((num_pcr + 7) / 8); u32 size_select_offset = hash_offset + offsetof(struct tpms_pcr_selection, size_of_select); u32 pcr_select_offset = hash_offset + offsetof(struct tpms_pcr_selection, pcr_select); pcrs.selection[i].hash = get_unaligned_be16(response + hash_offset); pcrs.selection[i].size_of_select = __get_unaligned_be(response + size_select_offset); if (pcrs.selection[i].size_of_select > TPM2_PCR_SELECT_MAX) goto out; /* copy the array of pcr_select */ memcpy(pcrs.selection[i].pcr_select, response + pcr_select_offset, pcrs.selection[i].size_of_select); } for (i = 0; i < pcrs.count; i++) { u32 hash_mask = alg_to_mask(pcrs.selection[i].hash); if (hash_mask) { *supported_pcr |= hash_mask; if (is_active_pcr(&pcrs.selection[i])) *active_pcr |= hash_mask; } else { EFI_PRINT("Unknown algorithm %x\n", pcrs.selection[i].hash); } } *pcr_banks = pcrs.count; return 0; out: return -1; } /** * __get_active_pcr_banks() - returns the currently active PCR banks * * @active_pcr_banks: pointer for receiving the bitmap of currently * active PCR banks * * Return: status code */ static efi_status_t __get_active_pcr_banks(u32 *active_pcr_banks) { struct udevice *dev; u32 active = 0, supported = 0, pcr_banks = 0; efi_status_t ret; int err; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) goto out; err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks); if (err) { ret = EFI_DEVICE_ERROR; goto out; } *active_pcr_banks = active; out: return ret; } /* tcg2_create_digest - create a list of digests of the supported PCR banks * for a given memory range * * @input: input memory * @length: length of buffer to calculate the digest * @digest_list: list of digests to fill in * * Return: status code */ static efi_status_t tcg2_create_digest(const u8 *input, u32 length, struct tpml_digest_values *digest_list) { sha1_context ctx; sha256_context ctx_256; sha512_context ctx_512; u8 final[TPM2_SHA512_DIGEST_SIZE]; efi_status_t ret; u32 active; size_t i; ret = __get_active_pcr_banks(&active); if (ret != EFI_SUCCESS) return ret; digest_list->count = 0; for (i = 0; i < MAX_HASH_COUNT; i++) { u16 hash_alg = hash_algo_list[i].hash_alg; if (!(active & alg_to_mask(hash_alg))) continue; switch (hash_alg) { case TPM2_ALG_SHA1: sha1_starts(&ctx); sha1_update(&ctx, input, length); sha1_finish(&ctx, final); break; case TPM2_ALG_SHA256: sha256_starts(&ctx_256); sha256_update(&ctx_256, input, length); sha256_finish(&ctx_256, final); break; case TPM2_ALG_SHA384: sha384_starts(&ctx_512); sha384_update(&ctx_512, input, length); sha384_finish(&ctx_512, final); break; case TPM2_ALG_SHA512: sha512_starts(&ctx_512); sha512_update(&ctx_512, input, length); sha512_finish(&ctx_512, final); break; default: EFI_PRINT("Unsupported algorithm %x\n", hash_alg); return EFI_INVALID_PARAMETER; } digest_list->digests[digest_list->count].hash_alg = hash_alg; memcpy(&digest_list->digests[digest_list->count].digest, final, (u32)alg_to_len(hash_alg)); digest_list->count++; } return EFI_SUCCESS; } /** * 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 = platform_get_tpm2_device(&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 = platform_get_tpm2_device(&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]; 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 = __get_active_pcr_banks(&active); if (ret != EFI_SUCCESS) { goto out; } digest_list->count = 0; for (i = 0; i < MAX_HASH_COUNT; i++) { u16 hash_alg = hash_algo_list[i].hash_alg; if (!(active & alg_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: EFI_PRINT("Unsupported algorithm %x\n", hash_alg); return EFI_INVALID_PARAMETER; } digest_list->digests[digest_list->count].hash_alg = hash_alg; memcpy(&digest_list->digests[digest_list->count].digest, hash, (u32)alg_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; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) return ret; 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 = platform_get_tpm2_device(&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((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(__maybe_unused struct efi_tcg2_protocol *this, u32 __maybe_unused input_param_block_size, u8 __maybe_unused *input_param_block, u32 __maybe_unused output_param_block_size, u8 __maybe_unused *output_param_block) { return EFI_UNSUPPORTED; } /** * 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) { efi_status_t ret; if (!this || !active_pcr_banks) { ret = EFI_INVALID_PARAMETER; goto out; } EFI_ENTRY("%p, %p", this, active_pcr_banks); ret = __get_active_pcr_banks(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, }; /** * create_specid_event() - Create the first event in the eventlog * * @dev: tpm device * @event_header: Pointer to the final event header * @event_size: final spec event size * * Return: status code */ static efi_status_t create_specid_event(struct udevice *dev, void *buffer, size_t *event_size) { struct tcg_efi_spec_id_event *spec_event; size_t spec_event_size; efi_status_t ret = EFI_DEVICE_ERROR; u32 active = 0, supported = 0, pcr_count = 0, alg_count = 0; int err; size_t i; /* * Create Spec event. This needs to be the first event in the log * according to the TCG EFI protocol spec */ /* Setup specID event data */ spec_event = (struct tcg_efi_spec_id_event *)buffer; memcpy(spec_event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03, sizeof(spec_event->signature)); put_unaligned_le32(0, &spec_event->platform_class); /* type client */ spec_event->spec_version_minor = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2; spec_event->spec_version_major = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2; spec_event->spec_errata = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2; spec_event->uintn_size = sizeof(efi_uintn_t) / sizeof(u32); err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_count); if (err) goto out; for (i = 0; i < pcr_count; i++) { u16 hash_alg = hash_algo_list[i].hash_alg; u16 hash_len = hash_algo_list[i].hash_len; if (active & alg_to_mask(hash_alg)) { put_unaligned_le16(hash_alg, &spec_event->digest_sizes[alg_count].algorithm_id); put_unaligned_le16(hash_len, &spec_event->digest_sizes[alg_count].digest_size); alg_count++; } } spec_event->number_of_algorithms = alg_count; if (spec_event->number_of_algorithms > MAX_HASH_COUNT || spec_event->number_of_algorithms < 1) goto out; /* * the size of the spec event and placement of vendor_info_size * depends on supported algoriths */ spec_event_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes) + spec_event->number_of_algorithms * sizeof(spec_event->digest_sizes[0]); /* no vendor info for us */ memset(buffer + spec_event_size, 0, 1); /* add a byte for vendor_info_size in the spec event */ spec_event_size += 1; *event_size = spec_event_size; return EFI_SUCCESS; out: return ret; } /** * 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; } /** * 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; } /** * efi_init_event_log() - initialize an eventlog */ 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 tcg_pcr_event *event_header = NULL; struct udevice *dev; size_t spec_event_size; efi_status_t ret; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) goto out; ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, TPM2_EVENT_LOG_SIZE, (void **)&event_log.buffer); if (ret != EFI_SUCCESS) goto out; /* * 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); event_log.pos = 0; event_log.last_event_size = 0; event_log.get_event_called = false; event_log.truncated = false; /* * The log header is defined to be in SHA1 event log entry format. * Setup event header */ event_header = (struct tcg_pcr_event *)event_log.buffer; put_unaligned_le32(0, &event_header->pcr_index); put_unaligned_le32(EV_NO_ACTION, &event_header->event_type); memset(&event_header->digest, 0, sizeof(event_header->digest)); ret = create_specid_event(dev, (void *)((uintptr_t)event_log.buffer + sizeof(*event_header)), &spec_event_size); if (ret != EFI_SUCCESS) goto free_pool; put_unaligned_le32(spec_event_size, &event_header->event_size); event_log.pos = spec_event_size + sizeof(*event_header); event_log.last_event_size = event_log.pos; ret = create_final_event(); if (ret != EFI_SUCCESS) goto free_pool; out: return ret; free_pool: efi_free_pool(event_log.buffer); event_log.buffer = NULL; return ret; } /** * tcg2_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 tcg2_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(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 = tcg2_measure_event(dev, 0, EV_S_CRTM_VERSION, strlen(version_string) + 1, (u8 *)version_string); 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 = tcg2_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[] = L"BootOrder"; u16 boot_name[] = L"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) { ret = EFI_NOT_FOUND; goto error; } 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_info("%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 smbios_entry *entry) { efi_status_t ret; struct smbios_header *smbios_copy; struct smbios_handoff_table_pointers2 *event = NULL; u32 event_size; /* * 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->struct_table_length; 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, &smbios_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->struct_table_length); smbios_prepare_measurement(entry, smbios_copy); ret = tcg2_measure_event(dev, 1, EV_EFI_HANDOFF_TABLES2, event_size, (u8 *)event); if (ret != EFI_SUCCESS) goto out; out: free(event); return ret; } /** * find_smbios_table() - find smbios table * * Return: pointer to the smbios table */ static void *find_smbios_table(void) { u32 i; for (i = 0; i < systab.nr_tables; i++) { if (!guidcmp(&smbios_guid, &systab.tables[i].guid)) return systab.tables[i].table; } return NULL; } /** * efi_tcg2_measure_efi_app_invocation() - measure efi app invocation * * Return: status code */ efi_status_t efi_tcg2_measure_efi_app_invocation(void) { efi_status_t ret; u32 pcr_index; struct udevice *dev; u32 event = 0; struct smbios_entry *entry; if (tcg2_efi_app_invoked) return EFI_SUCCESS; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) return ret; ret = tcg2_measure_boot_variable(dev); if (ret != EFI_SUCCESS) goto out; ret = tcg2_measure_event(dev, 4, EV_EFI_ACTION, strlen(EFI_CALLING_EFI_APPLICATION), (u8 *)EFI_CALLING_EFI_APPLICATION); if (ret != EFI_SUCCESS) goto out; entry = (struct smbios_entry *)find_smbios_table(); if (entry) { ret = tcg2_measure_smbios(dev, entry); if (ret != EFI_SUCCESS) goto out; } for (pcr_index = 0; pcr_index <= 7; pcr_index++) { ret = tcg2_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; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) return ret; ret = tcg2_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); ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) goto out; ret = tcg2_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 = tcg2_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; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) goto out; ret = tcg2_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 = tcg2_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; 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]); /* * According to the TCG2 PC Client PFP spec, "SecureBoot", * "PK", "KEK", "db" and "dbx" variables must be measured * even if they are empty. */ data = efi_get_var(secure_variables[i], guid, &data_size); ret = tcg2_measure_variable(dev, 7, EV_EFI_VARIABLE_DRIVER_CONFIG, secure_variables[i], guid, data_size, data); free(data); if (ret != EFI_SUCCESS) goto error; } /* * TCG2 PC Client PFP spec says "dbt" and "dbr" are * measured if present and not empty. */ data = efi_get_var(L"dbt", &efi_guid_image_security_database, &data_size); if (data) { ret = tcg2_measure_variable(dev, 7, EV_EFI_VARIABLE_DRIVER_CONFIG, L"dbt", &efi_guid_image_security_database, data_size, data); free(data); } data = efi_get_var(L"dbr", &efi_guid_image_security_database, &data_size); if (data) { ret = tcg2_measure_variable(dev, 7, EV_EFI_VARIABLE_DRIVER_CONFIG, L"dbr", &efi_guid_image_security_database, data_size, data); free(data); } error: return ret; } /** * efi_tcg2_register() - register EFI_TCG2_PROTOCOL * * If a TPM2 device is available, the TPM TCG2 Protocol is registered * * Return: An error status is only returned if adding the protocol fails. */ efi_status_t efi_tcg2_register(void) { efi_status_t ret = EFI_SUCCESS; struct udevice *dev; struct efi_event *event; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) { log_warning("Unable to find TPMv2 device\n"); return EFI_SUCCESS; } ret = efi_init_event_log(); if (ret != EFI_SUCCESS) goto fail; ret = efi_append_scrtm_version(dev); if (ret != EFI_SUCCESS) { tcg2_uninit(); goto fail; } ret = efi_add_protocol(efi_root, &efi_guid_tcg2_protocol, (void *)&efi_tcg2_protocol); 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; } ret = tcg2_measure_secure_boot_variable(dev); if (ret != EFI_SUCCESS) { tcg2_uninit(); goto fail; } return ret; fail: log_err("Cannot install EFI_TCG2_PROTOCOL\n"); /* * Return EFI_SUCCESS and don't stop the EFI subsystem. * That's done for 2 reasons * - If the protocol is not installed the PCRs won't be extended. So * someone later in the boot flow will notice that and take the * necessary actions. * - The TPM sandbox is limited and we won't be able to run any efi * related tests with TCG2 enabled */ return EFI_SUCCESS; }