diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/efi_loader/efi_variable.c | 231 |
1 files changed, 228 insertions, 3 deletions
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c index adb78470f2..fd5c41f830 100644 --- a/lib/efi_loader/efi_variable.c +++ b/lib/efi_loader/efi_variable.c @@ -16,8 +16,16 @@ #include <u-boot/crc.h> #include "../lib/crypto/pkcs7_parser.h" +enum efi_secure_mode { + EFI_MODE_SETUP, + EFI_MODE_USER, + EFI_MODE_AUDIT, + EFI_MODE_DEPLOYED, +}; + const efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID; static bool efi_secure_boot; +static int efi_secure_mode; #define READ_ONLY BIT(31) @@ -160,6 +168,210 @@ static const char *parse_attr(const char *str, u32 *attrp, u64 *timep) return str; } +static efi_status_t efi_set_variable_internal(u16 *variable_name, + const efi_guid_t *vendor, + u32 attributes, + efi_uintn_t data_size, + const void *data, + bool ro_check); + +/** + * efi_transfer_secure_state - handle a secure boot state transition + * @mode: new state + * + * Depending on @mode, secure boot related variables are updated. + * Those variables are *read-only* for users, efi_set_variable_internal() + * is called here. + * + * Return: EFI_SUCCESS on success, status code (negative) on error + */ +static efi_status_t efi_transfer_secure_state(enum efi_secure_mode mode) +{ + u32 attributes; + u8 val; + efi_status_t ret; + + debug("Secure state from %d to %d\n", efi_secure_mode, mode); + + attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS | + EFI_VARIABLE_RUNTIME_ACCESS; + if (mode == EFI_MODE_DEPLOYED) { + val = 1; + ret = efi_set_variable_internal(L"SecureBoot", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"SetupMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"AuditMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 1; + ret = efi_set_variable_internal(L"DeployedMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + + efi_secure_boot = true; + } else if (mode == EFI_MODE_AUDIT) { + ret = efi_set_variable_internal(L"PK", + &efi_global_variable_guid, + attributes, + 0, NULL, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"SecureBoot", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 1; + ret = efi_set_variable_internal(L"SetupMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 1; + ret = efi_set_variable_internal(L"AuditMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"DeployedMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + + efi_secure_boot = true; + } else if (mode == EFI_MODE_USER) { + val = 1; + ret = efi_set_variable_internal(L"SecureBoot", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"SetupMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"AuditMode", + &efi_global_variable_guid, + attributes, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"DeployedMode", + &efi_global_variable_guid, + attributes, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + + efi_secure_boot = true; + } else if (mode == EFI_MODE_SETUP) { + val = 0; + ret = efi_set_variable_internal(L"SecureBoot", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 1; + ret = efi_set_variable_internal(L"SetupMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"AuditMode", + &efi_global_variable_guid, + attributes, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + val = 0; + ret = efi_set_variable_internal(L"DeployedMode", + &efi_global_variable_guid, + attributes | READ_ONLY, + sizeof(val), &val, + false); + if (ret != EFI_SUCCESS) + goto err; + } else { + return EFI_INVALID_PARAMETER; + } + + return EFI_SUCCESS; + +err: + /* TODO: What action should be taken here? */ + printf("ERROR: Secure state transition failed\n"); + return ret; +} + +/** + * efi_init_secure_state - initialize secure boot state + * + * Return: EFI_SUCCESS on success, status code (negative) on error + */ +static efi_status_t efi_init_secure_state(void) +{ + efi_uintn_t size = 0; + efi_status_t ret; + + ret = EFI_CALL(efi_get_variable(L"PK", &efi_global_variable_guid, + NULL, &size, NULL)); + if (ret == EFI_BUFFER_TOO_SMALL && IS_ENABLED(CONFIG_EFI_SECURE_BOOT)) + ret = efi_transfer_secure_state(EFI_MODE_USER); + else + ret = efi_transfer_secure_state(EFI_MODE_SETUP); + + return ret; +} + /** * efi_secure_boot_enabled - return if secure boot is enabled or not * @@ -910,10 +1122,19 @@ efi_status_t EFIAPI efi_set_variable_common(u16 *variable_name, EFI_PRINT("setting: %s=%s\n", native_name, val); out: - if (env_set(native_name, val)) + if (env_set(native_name, val)) { ret = EFI_DEVICE_ERROR; - else + } else { + if ((u16_strcmp(variable_name, L"PK") == 0 && + guidcmp(vendor, &efi_global_variable_guid) == 0)) { + ret = efi_transfer_secure_state( + (delete ? EFI_MODE_SETUP : + EFI_MODE_USER)); + if (ret != EFI_SUCCESS) + goto err; + } ret = EFI_SUCCESS; + } err: free(native_name); @@ -1098,5 +1319,9 @@ void efi_variables_boot_exit_notify(void) */ efi_status_t efi_init_variables(void) { - return EFI_SUCCESS; + efi_status_t ret; + + ret = efi_init_secure_state(); + + return ret; } |