[PATCH v5 4/5] eficonfig: add UEFI Secure Boot Key enrollment interface
Etienne Carriere
etienne.carriere at linaro.org
Tue Oct 25 10:15:07 CEST 2022
Hello Kojima-san,
On Tue, 25 Oct 2022 at 05:17, Masahisa Kojima
<masahisa.kojima at linaro.org> wrote:
>
> This commit adds the menu-driven UEFI Secure Boot Key
> enrollment interface. User can enroll the PK, KEK, db
> and dbx by selecting EFI Signature Lists file.
> After the PK is enrolled, UEFI Secure Boot is enabled and
> EFI Signature Lists file must be signed by KEK or PK.
>
> Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
> ---
> No change since v4
>
> Changes in v4:
> - add CONFIG_EFI_MM_COMM_TEE dependency
> - fix error handling
>
> Changes in v3:
> - fix error handling
>
> Changes in v2:
> - allow to enroll .esl file
> - fix typos
> - add function comments
>
> cmd/Makefile | 5 +
> cmd/eficonfig.c | 3 +
> cmd/eficonfig_sbkey.c | 357 ++++++++++++++++++++++++++++++++++++++++++
> include/efi_config.h | 5 +
> 4 files changed, 370 insertions(+)
> create mode 100644 cmd/eficonfig_sbkey.c
>
> diff --git a/cmd/Makefile b/cmd/Makefile
> index c95e09d058..e43ef22e98 100644
> --- a/cmd/Makefile
> +++ b/cmd/Makefile
> @@ -66,6 +66,11 @@ obj-$(CONFIG_CMD_EEPROM) += eeprom.o
> obj-$(CONFIG_EFI) += efi.o
> obj-$(CONFIG_CMD_EFIDEBUG) += efidebug.o
> obj-$(CONFIG_CMD_EFICONFIG) += eficonfig.o
> +ifdef CONFIG_CMD_EFICONFIG
> +ifdef CONFIG_EFI_MM_COMM_TEE
> +obj-$(CONFIG_EFI_SECURE_BOOT) += eficonfig_sbkey.o
> +endif
> +endif
> obj-$(CONFIG_CMD_ELF) += elf.o
> obj-$(CONFIG_CMD_EROFS) += erofs.o
> obj-$(CONFIG_HUSH_PARSER) += exit.o
> diff --git a/cmd/eficonfig.c b/cmd/eficonfig.c
> index c765b795d0..0b643a046c 100644
> --- a/cmd/eficonfig.c
> +++ b/cmd/eficonfig.c
> @@ -2447,6 +2447,9 @@ static const struct eficonfig_item maintenance_menu_items[] = {
> {"Edit Boot Option", eficonfig_process_edit_boot_option},
> {"Change Boot Order", eficonfig_process_change_boot_order},
> {"Delete Boot Option", eficonfig_process_delete_boot_option},
> +#if (CONFIG_IS_ENABLED(EFI_SECURE_BOOT) && CONFIG_IS_ENABLED(EFI_MM_COMM_TEE))
> + {"Secure Boot Configuration", eficonfig_process_secure_boot_config},
> +#endif
> {"Quit", eficonfig_process_quit},
> };
>
> diff --git a/cmd/eficonfig_sbkey.c b/cmd/eficonfig_sbkey.c
> new file mode 100644
> index 0000000000..32a39eb7ba
> --- /dev/null
> +++ b/cmd/eficonfig_sbkey.c
> @@ -0,0 +1,357 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Menu-driven UEFI Secure Boot Key Maintenance
> + *
> + * Copyright (c) 2022 Masahisa Kojima, Linaro Limited
> + */
> +
> +#include <ansi.h>
> +#include <common.h>
> +#include <charset.h>
> +#include <hexdump.h>
> +#include <log.h>
> +#include <malloc.h>
> +#include <menu.h>
> +#include <efi_loader.h>
> +#include <efi_config.h>
> +#include <efi_variable.h>
> +#include <crypto/pkcs7_parser.h>
> +
> +enum efi_sbkey_signature_type {
> + SIG_TYPE_X509 = 0,
> + SIG_TYPE_HASH,
> + SIG_TYPE_CRL,
> + SIG_TYPE_RSA2048,
> +};
> +
> +struct eficonfig_sigtype_to_str {
> + efi_guid_t sig_type;
> + char *str;
> + enum efi_sbkey_signature_type type;
> +};
> +
> +static const struct eficonfig_sigtype_to_str sigtype_to_str[] = {
> + {EFI_CERT_X509_GUID, "X509", SIG_TYPE_X509},
> + {EFI_CERT_SHA256_GUID, "SHA256", SIG_TYPE_HASH},
> + {EFI_CERT_X509_SHA256_GUID, "X509_SHA256 CRL", SIG_TYPE_CRL},
> + {EFI_CERT_X509_SHA384_GUID, "X509_SHA384 CRL", SIG_TYPE_CRL},
> + {EFI_CERT_X509_SHA512_GUID, "X509_SHA512 CRL", SIG_TYPE_CRL},
> + /* U-Boot does not support the following signature types */
> +/* {EFI_CERT_RSA2048_GUID, "RSA2048", SIG_TYPE_RSA2048}, */
> +/* {EFI_CERT_RSA2048_SHA256_GUID, "RSA2048_SHA256", SIG_TYPE_RSA2048}, */
> +/* {EFI_CERT_SHA1_GUID, "SHA1", SIG_TYPE_HASH}, */
> +/* {EFI_CERT_RSA2048_SHA_GUID, "RSA2048_SHA", SIG_TYPE_RSA2048 }, */
> +/* {EFI_CERT_SHA224_GUID, "SHA224", SIG_TYPE_HASH}, */
> +/* {EFI_CERT_SHA384_GUID, "SHA384", SIG_TYPE_HASH}, */
> +/* {EFI_CERT_SHA512_GUID, "SHA512", SIG_TYPE_HASH}, */
> +};
> +
> +/**
> + * is_secureboot_enabled() - check UEFI Secure Boot is enabled
> + *
> + * Return: true when UEFI Secure Boot is enabled, false otherwise
> + */
> +static bool is_secureboot_enabled(void)
> +{
> + efi_status_t ret;
> + u8 secure_boot;
> + efi_uintn_t size;
> +
> + size = sizeof(secure_boot);
> + ret = efi_get_variable_int(u"SecureBoot", &efi_global_variable_guid,
> + NULL, &size, &secure_boot, NULL);
> +
> + return secure_boot == 1;
This should test 'ret{ against EFI_SUCCESS and EFI_NOT_FOUND.
I think the logic should be:
if (ret == EFI_SUCCESS) { return secure_boot == 1; }
else if (ret == EFI_NOT_FOUND) { return false; }
else { /* enforce secure bool policy on error */ return true; }
That said, there is the exported efi_secure_boot_enabled() that should
be reliable, i think.
> +}
> +
> +/**
> + * create_time_based_payload() - create payload for time based authenticate variable
> + *
> + * @db: pointer to the original signature database
> + * @new_db: pointer to the authenticated variable payload
> + * @size: pointer to payload size
> + * Return: status code
> + */
> +static efi_status_t create_time_based_payload(void *db, void **new_db, efi_uintn_t *size)
> +{
> + efi_status_t ret;
> + struct efi_time time;
> + efi_uintn_t total_size;
> + struct efi_variable_authentication_2 *auth;
> +
> + *new_db = NULL;
> +
> + /*
> + * SetVariable() call with EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS
> + * attribute requires EFI_VARIABLE_AUTHENTICATED_2 descriptor, prepare it
> + * without certificate data in it.
> + */
> + total_size = sizeof(struct efi_variable_authentication_2) + *size;
> +
> + auth = calloc(1, total_size);
> + if (!auth)
> + return EFI_OUT_OF_RESOURCES;
> +
> + ret = EFI_CALL((*efi_runtime_services.get_time)(&time, NULL));
> + if (ret != EFI_SUCCESS) {
> + free(auth);
> + return EFI_OUT_OF_RESOURCES;
> + }
> + time.pad1 = 0;
> + time.nanosecond = 0;
> + time.timezone = 0;
> + time.daylight = 0;
> + time.pad2 = 0;
> + memcpy(&auth->time_stamp, &time, sizeof(time));
> + auth->auth_info.hdr.dwLength = sizeof(struct win_certificate_uefi_guid);
> + auth->auth_info.hdr.wRevision = 0x0200;
Can use WIN_CERT_REVISION_2_0 from pe.h.
Regards,
etienne
> + auth->auth_info.hdr.wCertificateType = WIN_CERT_TYPE_EFI_GUID;
> + guidcpy(&auth->auth_info.cert_type, &efi_guid_cert_type_pkcs7);
> + if (db)
> + memcpy((u8 *)auth + sizeof(struct efi_variable_authentication_2), db, *size);
> +
> + *new_db = auth;
> + *size = total_size;
> +
> + return EFI_SUCCESS;
> +}
> +
> (snip)
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