diff mbox series

[v8,4/5] eficonfig: add UEFI Secure Boot Key enrollment interface

Message ID 20221110083054.11950-5-masahisa.kojima@linaro.org
State Superseded
Headers show
Series eficonfig: add UEFI Secure Boot key maintenance interface | expand

Commit Message

Masahisa Kojima Nov. 10, 2022, 8:30 a.m. UTC 
This commit adds the menu-driven UEFI Secure Boot Key
enrollment interface. User can enroll PK, KEK, db
and dbx by selecting file.
Only the signed EFI Signature List(s) with an authenticated
header, typically '.auth' file, is accepted.

To clear the PK, KEK, db and dbx, user needs to enroll the null key
signed by PK or KEK.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
---
Changes in v8:
- fix missing efi_file_close_int() call

Changes in v7:
- only accept .auth file.
- remove creating time based authenticated variable
- update commit message
- use efi_file_size()

Changes in v6:
- use efi_secure_boot_enabled()
- replace with WIN_CERT_REVISION_2_0 from pe.h
- call efi_build_signature_store() to check the valid EFI Signature List
- update comment

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 | 244 ++++++++++++++++++++++++++++++++++++++++++
 include/efi_config.h  |   5 +
 4 files changed, 257 insertions(+)
 create mode 100644 cmd/eficonfig_sbkey.c

Comments

Ilias Apalodimas Nov. 11, 2022, 12:33 p.m. UTC | #1 
Hello Kojima-san!

[...]

> +	file_info.current_path = calloc(1, EFICONFIG_FILE_PATH_BUF_SIZE);
> +	if (!file_info.current_path) {
> +		ret = EFI_OUT_OF_RESOURCES;
> +		goto out;
> +	}
> +
> +	ret = eficonfig_process_select_file(&file_info);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = efi_open_volume_int(file_info.current_volume, &root);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = efi_file_open_int(root, &f, file_info.current_path, EFI_FILE_MODE_READ, 0);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	ret = efi_file_size(f, &size);
> +	if (ret != EFI_SUCCESS)
> +		goto out;
> +
> +	buf = calloc(1, size);
> +	if (!buf) {
> +		ret = EFI_OUT_OF_RESOURCES;
> +		goto out;
> +	}
> +	if (size == 0) {
> +		eficonfig_print_msg("ERROR! File is empty.");
> +		goto out;
> +	}

This needs to move before the allocation and if (!size)

> +
> +	ret = efi_file_read_int(f, &size, buf);
> +	if (ret != EFI_SUCCESS) {
> +		eficonfig_print_msg("ERROR! Failed to read file.");
> +		goto out;
> +	}
> +	if (!file_have_auth_header(buf, size)) {
> +		eficonfig_print_msg("ERROR! Invalid file format. Only .auth variables is allowed.");
> +		ret = EFI_INVALID_PARAMETER;
> +		goto out;
> +	}
> +
> +	attr = EFI_VARIABLE_NON_VOLATILE |
> +	       EFI_VARIABLE_BOOTSERVICE_ACCESS |
> +	       EFI_VARIABLE_RUNTIME_ACCESS |
> +	       EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
> +
> +	/* PK can enroll only one certificate */
> +	if (u16_strcmp(data, u"PK")) {
> +		efi_uintn_t db_size = 0;
> +
> +		/* check the variable exists. If exists, add APPEND_WRITE attribute */
> +		ret = efi_get_variable_int(data, efi_auth_var_get_guid(data), NULL,
> +					   &db_size, NULL,  NULL);
> +		if (ret == EFI_BUFFER_TOO_SMALL)
> +			attr |= EFI_VARIABLE_APPEND_WRITE;
> +	}
> +
> +	ret = efi_set_variable_int((u16 *)data, efi_auth_var_get_guid((u16 *)data),
> +				   attr, size, buf, false);
> +	if (ret != EFI_SUCCESS)
> +		eficonfig_print_msg("ERROR! Failed to update signature database");
> +
> +out:
> +	free(file_info.current_path);
> +	free(buf);
> +	if (f)
> +		efi_file_close_int(f);
> +
> +	/* return to the parent menu */
> +	ret = (ret == EFI_ABORTED) ? EFI_NOT_READY : ret;

I assume we are changing the return message here because the upper layers
can't handle EFI_ABORTED?

> +
> +	return ret;
> +}
> +
> +static struct eficonfig_item key_config_menu_items[] = {
> +	{"Enroll New Key", eficonfig_process_enroll_key},
> +	{"Quit", eficonfig_process_quit},
> +};
> +
 
with the size changes 
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Masahisa Kojima Nov. 14, 2022, 12:49 a.m. UTC | #2 
Hi Ilias,

On Fri, 11 Nov 2022 at 21:33, Ilias Apalodimas
<ilias.apalodimas@linaro.org> wrote:
>
> Hello Kojima-san!
>
> [...]
>
> > +     file_info.current_path = calloc(1, EFICONFIG_FILE_PATH_BUF_SIZE);
> > +     if (!file_info.current_path) {
> > +             ret = EFI_OUT_OF_RESOURCES;
> > +             goto out;
> > +     }
> > +
> > +     ret = eficonfig_process_select_file(&file_info);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     ret = efi_open_volume_int(file_info.current_volume, &root);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     ret = efi_file_open_int(root, &f, file_info.current_path, EFI_FILE_MODE_READ, 0);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     ret = efi_file_size(f, &size);
> > +     if (ret != EFI_SUCCESS)
> > +             goto out;
> > +
> > +     buf = calloc(1, size);
> > +     if (!buf) {
> > +             ret = EFI_OUT_OF_RESOURCES;
> > +             goto out;
> > +     }
> > +     if (size == 0) {
> > +             eficonfig_print_msg("ERROR! File is empty.");
> > +             goto out;
> > +     }
>
> This needs to move before the allocation and if (!size)

OK.

>
> > +
> > +     ret = efi_file_read_int(f, &size, buf);
> > +     if (ret != EFI_SUCCESS) {
> > +             eficonfig_print_msg("ERROR! Failed to read file.");
> > +             goto out;
> > +     }
> > +     if (!file_have_auth_header(buf, size)) {
> > +             eficonfig_print_msg("ERROR! Invalid file format. Only .auth variables is allowed.");
> > +             ret = EFI_INVALID_PARAMETER;
> > +             goto out;
> > +     }
> > +
> > +     attr = EFI_VARIABLE_NON_VOLATILE |
> > +            EFI_VARIABLE_BOOTSERVICE_ACCESS |
> > +            EFI_VARIABLE_RUNTIME_ACCESS |
> > +            EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
> > +
> > +     /* PK can enroll only one certificate */
> > +     if (u16_strcmp(data, u"PK")) {
> > +             efi_uintn_t db_size = 0;
> > +
> > +             /* check the variable exists. If exists, add APPEND_WRITE attribute */
> > +             ret = efi_get_variable_int(data, efi_auth_var_get_guid(data), NULL,
> > +                                        &db_size, NULL,  NULL);
> > +             if (ret == EFI_BUFFER_TOO_SMALL)
> > +                     attr |= EFI_VARIABLE_APPEND_WRITE;
> > +     }
> > +
> > +     ret = efi_set_variable_int((u16 *)data, efi_auth_var_get_guid((u16 *)data),
> > +                                attr, size, buf, false);
> > +     if (ret != EFI_SUCCESS)
> > +             eficonfig_print_msg("ERROR! Failed to update signature database");
> > +
> > +out:
> > +     free(file_info.current_path);
> > +     free(buf);
> > +     if (f)
> > +             efi_file_close_int(f);
> > +
> > +     /* return to the parent menu */
> > +     ret = (ret == EFI_ABORTED) ? EFI_NOT_READY : ret;
>
> I assume we are changing the return message here because the upper layers
> can't handle EFI_ABORTED?

This return value change is tricky.
In eficonfig menu handling, EFI_ABORTED means "exit from the current
menu", it usually happens
by selecting "Quit" entry or pressing ESC key.
eficonfig menu implements a multi-layer menu, if the child menu
returns with EFI_ABORTED,
the parent menu also exit with EFI_ABORTED. This is why EFI_ABORTED is
changed to EFI_NOT_READY.
EFI_NOT_READY means that we stay in the current menu.

>
> > +
> > +     return ret;
> > +}
> > +
> > +static struct eficonfig_item key_config_menu_items[] = {
> > +     {"Enroll New Key", eficonfig_process_enroll_key},
> > +     {"Quit", eficonfig_process_quit},
> > +};
> > +
>
> with the size changes
> Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Thanks,
Masahisa Kojima

>
diff mbox series

Patch

diff --git a/cmd/Makefile b/cmd/Makefile
index 2444d116c0..0b6a96c1d9 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 12babb76c2..d79194794b 100644
--- a/cmd/eficonfig.c
+++ b/cmd/eficonfig.c
@@ -2435,6 +2435,9 @@  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..de1d1e8426
--- /dev/null
+++ b/cmd/eficonfig_sbkey.c
@@ -0,0 +1,244 @@ 
+// 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}, */
+};
+
+/**
+ * file_have_auth_header() - check file has EFI_VARIABLE_AUTHENTICATION_2 header
+ * @buf:	pointer to file
+ * @size:	file size
+ * Return:	true if file has auth header, false otherwise
+ */
+static bool file_have_auth_header(void *buf, efi_uintn_t size)
+{
+	struct efi_variable_authentication_2 *auth = buf;
+
+	if (auth->auth_info.hdr.wCertificateType != WIN_CERT_TYPE_EFI_GUID)
+		return false;
+
+	if (guidcmp(&auth->auth_info.cert_type, &efi_guid_cert_type_pkcs7))
+		return false;
+
+	return true;
+}
+
+/**
+ * eficonfig_process_enroll_key() - enroll key into signature database
+ *
+ * @data:	pointer to the data for each entry
+ * Return:	status code
+ */
+static efi_status_t eficonfig_process_enroll_key(void *data)
+{
+	u32 attr;
+	char *buf = NULL;
+	efi_uintn_t size;
+	efi_status_t ret;
+	struct efi_file_handle *root;
+	struct efi_file_handle *f = NULL;
+	struct eficonfig_select_file_info file_info;
+
+	file_info.current_path = calloc(1, EFICONFIG_FILE_PATH_BUF_SIZE);
+	if (!file_info.current_path) {
+		ret = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
+	ret = eficonfig_process_select_file(&file_info);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = efi_open_volume_int(file_info.current_volume, &root);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = efi_file_open_int(root, &f, file_info.current_path, EFI_FILE_MODE_READ, 0);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = efi_file_size(f, &size);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	buf = calloc(1, size);
+	if (!buf) {
+		ret = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+	if (size == 0) {
+		eficonfig_print_msg("ERROR! File is empty.");
+		goto out;
+	}
+
+	ret = efi_file_read_int(f, &size, buf);
+	if (ret != EFI_SUCCESS) {
+		eficonfig_print_msg("ERROR! Failed to read file.");
+		goto out;
+	}
+	if (!file_have_auth_header(buf, size)) {
+		eficonfig_print_msg("ERROR! Invalid file format. Only .auth variables is allowed.");
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	attr = EFI_VARIABLE_NON_VOLATILE |
+	       EFI_VARIABLE_BOOTSERVICE_ACCESS |
+	       EFI_VARIABLE_RUNTIME_ACCESS |
+	       EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS;
+
+	/* PK can enroll only one certificate */
+	if (u16_strcmp(data, u"PK")) {
+		efi_uintn_t db_size = 0;
+
+		/* check the variable exists. If exists, add APPEND_WRITE attribute */
+		ret = efi_get_variable_int(data, efi_auth_var_get_guid(data), NULL,
+					   &db_size, NULL,  NULL);
+		if (ret == EFI_BUFFER_TOO_SMALL)
+			attr |= EFI_VARIABLE_APPEND_WRITE;
+	}
+
+	ret = efi_set_variable_int((u16 *)data, efi_auth_var_get_guid((u16 *)data),
+				   attr, size, buf, false);
+	if (ret != EFI_SUCCESS)
+		eficonfig_print_msg("ERROR! Failed to update signature database");
+
+out:
+	free(file_info.current_path);
+	free(buf);
+	if (f)
+		efi_file_close_int(f);
+
+	/* return to the parent menu */
+	ret = (ret == EFI_ABORTED) ? EFI_NOT_READY : ret;
+
+	return ret;
+}
+
+static struct eficonfig_item key_config_menu_items[] = {
+	{"Enroll New Key", eficonfig_process_enroll_key},
+	{"Quit", eficonfig_process_quit},
+};
+
+/**
+ * eficonfig_process_set_secure_boot_key() - display the key configuration menu
+ *
+ * @data:	pointer to the data for each entry
+ * Return:	status code
+ */
+static efi_status_t eficonfig_process_set_secure_boot_key(void *data)
+{
+	u32 i;
+	efi_status_t ret;
+	char header_str[32];
+	struct efimenu *efi_menu;
+
+	for (i = 0; i < ARRAY_SIZE(key_config_menu_items); i++)
+		key_config_menu_items[i].data = data;
+
+	snprintf(header_str, sizeof(header_str), "  ** Configure %ls **", (u16 *)data);
+
+	while (1) {
+		efi_menu = eficonfig_create_fixed_menu(key_config_menu_items,
+						       ARRAY_SIZE(key_config_menu_items));
+
+		ret = eficonfig_process_common(efi_menu, header_str);
+		eficonfig_destroy(efi_menu);
+
+		if (ret == EFI_ABORTED)
+			break;
+	}
+
+	/* return to the parent menu */
+	ret = (ret == EFI_ABORTED) ? EFI_NOT_READY : ret;
+
+	return ret;
+}
+
+static const struct eficonfig_item secure_boot_menu_items[] = {
+	{"PK", eficonfig_process_set_secure_boot_key, u"PK"},
+	{"KEK", eficonfig_process_set_secure_boot_key, u"KEK"},
+	{"db", eficonfig_process_set_secure_boot_key, u"db"},
+	{"dbx", eficonfig_process_set_secure_boot_key, u"dbx"},
+	{"Quit", eficonfig_process_quit},
+};
+
+/**
+ * eficonfig_process_secure_boot_config() - display the key list menu
+ *
+ * @data:	pointer to the data for each entry
+ * Return:	status code
+ */
+efi_status_t eficonfig_process_secure_boot_config(void *data)
+{
+	efi_status_t ret;
+	struct efimenu *efi_menu;
+
+	while (1) {
+		char header_str[64];
+
+		snprintf(header_str, sizeof(header_str),
+			 "  ** UEFI Secure Boot Key Configuration (SecureBoot : %s) **",
+			 (efi_secure_boot_enabled() ? "ON" : "OFF"));
+
+		efi_menu = eficonfig_create_fixed_menu(secure_boot_menu_items,
+						       ARRAY_SIZE(secure_boot_menu_items));
+		if (!efi_menu) {
+			ret = EFI_OUT_OF_RESOURCES;
+			break;
+		}
+
+		ret = eficonfig_process_common(efi_menu, header_str);
+		eficonfig_destroy(efi_menu);
+
+		if (ret == EFI_ABORTED)
+			break;
+	}
+
+	/* return to the parent menu */
+	ret = (ret == EFI_ABORTED) ? EFI_NOT_READY : ret;
+
+	return ret;
+}
diff --git a/include/efi_config.h b/include/efi_config.h
index 064f2efe3f..7a02fc68ac 100644
--- a/include/efi_config.h
+++ b/include/efi_config.h
@@ -99,5 +99,10 @@  efi_status_t eficonfig_append_menu_entry(struct efimenu *efi_menu,
 					 char *title, eficonfig_entry_func func,
 					 void *data);
 efi_status_t eficonfig_append_quit_entry(struct efimenu *efi_menu);
+void *eficonfig_create_fixed_menu(const struct eficonfig_item *items, int count);
+
+#ifdef CONFIG_EFI_SECURE_BOOT
+efi_status_t eficonfig_process_secure_boot_config(void *data);
+#endif
 
 #endif