// 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 #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 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, }, }; 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}, }; #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 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; } 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_pcr_read - Read PCRs for a TPM2 device for a given tpml_digest_values * * @dev: device * @pcr_index: PCR index * @digest_list: list of digest algorithms to extend * * @Return: status code */ static efi_status_t tcg2_pcr_read(struct udevice *dev, u32 pcr_index, struct tpml_digest_values *digest_list) { struct tpm_chip_priv *priv; unsigned int updates, pcr_select_min; u32 rc; size_t i; priv = dev_get_uclass_priv(dev); if (!priv) return EFI_DEVICE_ERROR; pcr_select_min = priv->pcr_select_min; 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; rc = tpm2_pcr_read(dev, pcr_index, pcr_select_min, hash_alg, digest, alg_to_len(hash_alg), &updates); if (rc) { EFI_PRINT("Failed to read PCR\n"); return EFI_DEVICE_ERROR; } } return EFI_SUCCESS; } /* put_event - 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 * */ static void put_event(u32 pcr_index, u32 event_type, struct tpml_digest_values *digest_list, u32 size, u8 event[], void *log) { size_t pos; size_t i; u32 event_size; /* * 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); 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 * This check should never fail. It checks the code above is * calculating the right length for the event we are adding */ if (pos != event_size) log_err("Appending to the EventLog failed\n"); } /* 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 + tcg_event_final_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; } put_event(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); put_event(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; } /** * 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; } /** * platform_get_eventlog() - retrieve the eventlog address and size * * This function retrieves the eventlog address and size if the underlying * firmware has done some measurements and passed them. * * This function may be overridden based on platform specific method of * passing the eventlog address and size. * * @dev: udevice * @addr: eventlog address * @sz: eventlog size * Return: status code */ __weak efi_status_t platform_get_eventlog(struct udevice *dev, u64 *addr, u32 *sz) { const u64 *basep; const u32 *sizep; basep = dev_read_prop(dev, "tpm_event_log_addr", NULL); if (!basep) return EFI_NOT_FOUND; *addr = be64_to_cpup((__force __be64 *)basep); sizep = dev_read_prop(dev, "tpm_event_log_size", NULL); if (!sizep) return EFI_NOT_FOUND; *sz = be32_to_cpup((__force __be32 *)sizep); if (*sz == 0) { log_debug("event log empty\n"); return EFI_NOT_FOUND; } return EFI_SUCCESS; } /** * 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: continue; } 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: continue; } 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; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; ret = platform_get_tpm2_device(&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 = 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(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 = platform_get_tpm2_device(&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) { 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, }; /** * parse_event_log_header() - Parse and verify the event log header fields * * @buffer: Pointer to the start of the eventlog * @size: Size of the eventlog * @pos: Return offset of the next event in buffer right * after the event header i.e specID * * Return: status code */ static efi_status_t parse_event_log_header(void *buffer, u32 size, u32 *pos) { struct tcg_pcr_event *event_header = (struct tcg_pcr_event *)buffer; int i = 0; if (size < sizeof(*event_header)) return EFI_COMPROMISED_DATA; if (get_unaligned_le32(&event_header->pcr_index) != 0 || get_unaligned_le32(&event_header->event_type) != EV_NO_ACTION) return EFI_COMPROMISED_DATA; for (i = 0; i < sizeof(event_header->digest); i++) { if (event_header->digest[i]) return EFI_COMPROMISED_DATA; } *pos += sizeof(*event_header); return EFI_SUCCESS; } /** * parse_specid_event() - Parse and verify the specID Event in the eventlog * * @dev: udevice * @buffer: Pointer to the start of the eventlog * @log_size: Size of the eventlog * @pos: [in] Offset of specID event in the eventlog buffer * [out] Return offset of the next event in the buffer * after the specID * @digest_list: list of digests in the event * * Return: status code * @pos Offset in the eventlog where the specID event ends * @digest_list: list of digests in the event */ static efi_status_t parse_specid_event(struct udevice *dev, void *buffer, u32 log_size, u32 *pos, struct tpml_digest_values *digest_list) { struct tcg_efi_spec_id_event *spec_event; struct tcg_pcr_event *event_header = (struct tcg_pcr_event *)buffer; size_t spec_event_size; u32 active = 0, supported = 0, pcr_count = 0, alg_count = 0; u32 spec_active = 0; u16 hash_alg; u8 vendor_sz; int err, i; if (*pos >= log_size || (*pos + sizeof(*spec_event)) > log_size) return EFI_COMPROMISED_DATA; /* Check specID event data */ spec_event = (struct tcg_efi_spec_id_event *)((uintptr_t)buffer + *pos); /* Check for signature */ if (memcmp(spec_event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03, sizeof(TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03))) { log_err("specID Event: Signature mismatch\n"); return EFI_COMPROMISED_DATA; } if (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) return EFI_COMPROMISED_DATA; if (spec_event->number_of_algorithms > MAX_HASH_COUNT || spec_event->number_of_algorithms < 1) { log_err("specID Event: Number of algorithms incorrect\n"); return EFI_COMPROMISED_DATA; } alg_count = spec_event->number_of_algorithms; err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_count); if (err) return EFI_DEVICE_ERROR; digest_list->count = 0; /* * We have to take care that the sequence of algorithms that we record * in digest_list matches the sequence in eventlog. */ for (i = 0; i < alg_count; i++) { hash_alg = get_unaligned_le16(&spec_event->digest_sizes[i].algorithm_id); if (!(supported & alg_to_mask(hash_alg))) { log_err("specID Event: Unsupported algorithm\n"); return EFI_COMPROMISED_DATA; } digest_list->digests[digest_list->count++].hash_alg = hash_alg; spec_active |= alg_to_mask(hash_alg); } /* * TCG specification expects the event log to have hashes for all * active PCR's */ if (spec_active != active) { /* * Previous stage bootloader should know all the active PCR's * and use them in the Eventlog. */ log_err("specID Event: All active hash alg not present\n"); return EFI_COMPROMISED_DATA; } /* * 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) + alg_count * sizeof(spec_event->digest_sizes[0]); if (*pos + spec_event_size >= log_size) return EFI_COMPROMISED_DATA; vendor_sz = *(uint8_t *)((uintptr_t)buffer + *pos + spec_event_size); spec_event_size += sizeof(vendor_sz) + vendor_sz; *pos += spec_event_size; if (get_unaligned_le32(&event_header->event_size) != spec_event_size) { log_err("specID event: header event size mismatch\n"); /* Right way to handle this can be to call SetActive PCR's */ return EFI_COMPROMISED_DATA; } return EFI_SUCCESS; } /** * tcg2_parse_event() - Parse the event in the eventlog * * @dev: udevice * @buffer: Pointer to the start of the eventlog * @log_size: Size of the eventlog * @offset: [in] Offset of the event in the eventlog buffer * [out] Return offset of the next event in the buffer * @digest_list: list of digests in the event * @pcr Index of the PCR in the event * * Return: status code */ static efi_status_t tcg2_parse_event(struct udevice *dev, void *buffer, u32 log_size, u32 *offset, struct tpml_digest_values *digest_list, u32 *pcr) { struct tcg_pcr_event2 *event = NULL; u32 count, size, event_size; size_t pos; event_size = tcg_event_final_size(digest_list); if (*offset >= log_size || *offset + event_size > log_size) { log_err("Event exceeds log size\n"); return EFI_COMPROMISED_DATA; } event = (struct tcg_pcr_event2 *)((uintptr_t)buffer + *offset); *pcr = get_unaligned_le32(&event->pcr_index); /* get the count */ count = get_unaligned_le32(&event->digests.count); if (count != digest_list->count) return EFI_COMPROMISED_DATA; pos = offsetof(struct tcg_pcr_event2, digests); pos += offsetof(struct tpml_digest_values, digests); for (int i = 0; i < digest_list->count; i++) { u16 alg; u16 hash_alg = digest_list->digests[i].hash_alg; u8 *digest = (u8 *)&digest_list->digests[i].digest; alg = get_unaligned_le16((void *)((uintptr_t)event + pos)); if (alg != hash_alg) return EFI_COMPROMISED_DATA; pos += offsetof(struct tpmt_ha, digest); memcpy(digest, (void *)((uintptr_t)event + pos), alg_to_len(hash_alg)); pos += alg_to_len(hash_alg); } size = get_unaligned_le32((void *)((uintptr_t)event + pos)); event_size += size; pos += sizeof(u32); /* tcg_pcr_event2 event_size*/ pos += size; /* make sure the calculated buffer is what we checked against */ if (pos != event_size) return EFI_COMPROMISED_DATA; if (pos > log_size) return EFI_COMPROMISED_DATA; *offset += pos; return EFI_SUCCESS; } /** * tcg2_get_fw_eventlog() - Get the eventlog address and size * * If the previous firmware has passed some eventlog, this function get it's * location and check for it's validity. * * @dev: udevice * @log_buffer: eventlog address * @log_sz: eventlog size * * Return: status code */ static efi_status_t tcg2_get_fw_eventlog(struct udevice *dev, void *log_buffer, size_t *log_sz) { struct tpml_digest_values digest_list; void *buffer; efi_status_t ret; u32 pcr, pos; u64 base; u32 sz; bool extend_pcr = false; int i; ret = platform_get_eventlog(dev, &base, &sz); if (ret != EFI_SUCCESS) return ret; if (sz > TPM2_EVENT_LOG_SIZE) return EFI_VOLUME_FULL; buffer = (void *)(uintptr_t)base; pos = 0; /* Parse the eventlog to check for its validity */ ret = parse_event_log_header(buffer, sz, &pos); if (ret) return ret; ret = parse_specid_event(dev, buffer, sz, &pos, &digest_list); if (ret) { log_err("Error parsing SPEC ID Event\n"); return ret; } ret = tcg2_pcr_read(dev, 0, &digest_list); if (ret) { log_err("Error reading PCR 0\n"); return ret; } /* * If PCR0 is 0, previous firmware didn't have the capability * to extend the PCR. In this scenario, extend the PCR as * the eventlog is parsed. */ for (i = 0; i < digest_list.count; i++) { u8 hash_buf[TPM2_SHA512_DIGEST_SIZE] = { 0 }; u16 hash_alg = digest_list.digests[i].hash_alg; if (!memcmp((u8 *)&digest_list.digests[i].digest, hash_buf, alg_to_len(hash_alg))) extend_pcr = true; } while (pos < sz) { ret = tcg2_parse_event(dev, buffer, sz, &pos, &digest_list, &pcr); if (ret) { log_err("Error parsing event\n"); return ret; } if (extend_pcr) { ret = tcg2_pcr_extend(dev, pcr, &digest_list); if (ret != EFI_SUCCESS) { log_err("Error in extending PCR\n"); return ret; } /* Clear the digest for next event */ 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; memset(digest, 0, alg_to_len(hash_alg)); } } } memcpy(log_buffer, buffer, sz); *log_sz = sz; return ret; } /** * 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; 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; } /** * 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; } /** * 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 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) 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_header = (struct tcg_pcr_event *)event_log.buffer; 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. */ ret = tcg2_get_fw_eventlog(dev, event_log.buffer, &event_log.pos); /* * If earlier firmware hasn't passed any eventlog, go ahead and * create the eventlog header. */ if (ret == EFI_NOT_FOUND) { 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; /* * Add SCRTM version to the log if previous firmmware * doesn't pass an eventlog. */ 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 = 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[] = 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 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; } /** * 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 = tcg2_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 = platform_get_tpm2_device(&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 = tcg2_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 smbios_entry *entry; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; if (tcg2_efi_app_invoked) return EFI_SUCCESS; ret = platform_get_tpm2_device(&dev); if (ret != EFI_SUCCESS) return EFI_SECURITY_VIOLATION; 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; } ret = tcg2_measure_gpt_data(dev, handle); 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; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; 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); event_log.ebs_called = true; if (!is_tcg2_protocol_installed()) { ret = EFI_SUCCESS; goto out; } 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; if (!is_tcg2_protocol_installed()) return EFI_SUCCESS; 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; 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 = platform_get_tpm2_device(&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 = platform_get_tpm2_device(&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; }