diff options
| -rw-r--r-- | include/efi_tcg2.h | 20 | ||||
| -rw-r--r-- | lib/efi_loader/efi_tcg2.c | 165 |
2 files changed, 185 insertions, 0 deletions
diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h index bcfb98168a..497ba3ce94 100644 --- a/include/efi_tcg2.h +++ b/include/efi_tcg2.h @@ -142,6 +142,26 @@ struct efi_tcg2_final_events_table { struct tcg_pcr_event2 event[]; }; +/** + * struct tdUEFI_VARIABLE_DATA - event log structure of UEFI variable + * @variable_name: The vendorGUID parameter in the + * GetVariable() API. + * @unicode_name_length: The length in CHAR16 of the Unicode name of + * the variable. + * @variable_data_length: The size of the variable data. + * @unicode_name: The CHAR16 unicode name of the variable + * without NULL-terminator. + * @variable_data: The data parameter of the efi variable + * in the GetVariable() API. + */ +struct efi_tcg2_uefi_variable_data { + efi_guid_t variable_name; + u64 unicode_name_length; + u64 variable_data_length; + u16 unicode_name[1]; + u8 variable_data[1]; +}; + struct efi_tcg2_protocol { efi_status_t (EFIAPI * get_capability)(struct efi_tcg2_protocol *this, struct efi_tcg2_boot_service_capability *capability); diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 1319a8b378..db3d6d7586 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -78,6 +78,19 @@ static const struct digest_info hash_algo_list[] = { }, }; +struct variable_info { + u16 *name; + const efi_guid_t *guid; +}; + +static struct variable_info secure_variables[] = { + {L"SecureBoot", &efi_global_variable_guid}, + {L"PK", &efi_global_variable_guid}, + {L"KEK", &efi_global_variable_guid}, + {L"db", &efi_guid_image_security_database}, + {L"dbx", &efi_guid_image_security_database}, +}; + #define MAX_HASH_COUNT ARRAY_SIZE(hash_algo_list) /** @@ -1265,6 +1278,39 @@ free_pool: } /** + * 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 * @@ -1295,6 +1341,118 @@ out: } /** + * 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, 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_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++) { + /* + * 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].name, + secure_variables[i].guid, + &data_size); + + ret = tcg2_measure_variable(dev, 7, + EV_EFI_VARIABLE_DRIVER_CONFIG, + secure_variables[i].name, + 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 @@ -1328,6 +1486,13 @@ efi_status_t efi_tcg2_register(void) tcg2_uninit(); goto fail; } + + ret = tcg2_measure_secure_boot_variable(dev); + if (ret != EFI_SUCCESS) { + tcg2_uninit(); + goto fail; + } + return ret; fail: |