u-boot/cmd/eficonfig_sbkey.c
Masahisa Kojima ad50ca5019 eficonfig: EFI_VARIABLE_APPEND_WRITE is not set for null key
The signed null key with authenticated header is used to clear
the PK, KEK, db and dbx. When CONFIG_EFI_MM_COMM_TEE is enabled
(StMM and OP-TEE based RPMB storage is used as the EFI variable
storage), clearing KEK, db and dbx by enrolling a signed null
key does not work as expected if EFI_VARIABLE_APPEND_WRITE
attritube is set.

This commit checks the selected file is null key, then
EFI_VARIABLE_APPEND_WRITE attibute will not be used for the null key.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2022-12-20 16:06:48 +01:00

533 lines
13 KiB
C

// 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>
struct eficonfig_sig_data {
struct efi_signature_list *esl;
struct efi_signature_data *esd;
struct list_head list;
u16 *varname;
};
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;
}
/**
* file_is_null_key() - check the file is an authenticated and signed null key
*
* @auth: pointer to the file
* @size: file size
* @null_key: pointer to store the result
* Return: status code
*/
static efi_status_t file_is_null_key(struct efi_variable_authentication_2 *auth,
efi_uintn_t size, bool *null_key)
{
efi_uintn_t auth_size =
sizeof(auth->time_stamp) + auth->auth_info.hdr.dwLength;
if (size < auth_size)
return EFI_INVALID_PARAMETER;
*null_key = (size == auth_size);
return EFI_SUCCESS;
}
/**
* 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;
bool null_key = false;
struct efi_file_handle *f = NULL;
struct efi_device_path *full_dp = 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;
full_dp = eficonfig_create_device_path(file_info.dp_volume, file_info.current_path);
if (!full_dp) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
f = efi_file_from_path(full_dp);
if (!f) {
ret = EFI_NOT_FOUND;
goto out;
}
size = 0;
ret = EFI_CALL(f->getinfo(f, &efi_file_info_guid, &size, NULL));
if (ret != EFI_BUFFER_TOO_SMALL)
goto out;
buf = malloc(size);
if (!buf) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
ret = EFI_CALL(f->getinfo(f, &efi_file_info_guid, &size, buf));
if (ret != EFI_SUCCESS)
goto out;
size = ((struct efi_file_info *)buf)->file_size;
free(buf);
if (!size) {
eficonfig_print_msg("ERROR! File is empty.");
ret = EFI_INVALID_PARAMETER;
goto out;
}
buf = malloc(size);
if (!buf) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
ret = EFI_CALL(f->read(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;
}
ret = file_is_null_key((struct efi_variable_authentication_2 *)buf,
size, &null_key);
if (ret != EFI_SUCCESS) {
eficonfig_print_msg("ERROR! Invalid file format.");
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.
* The signed null key is used to clear KEK, db and dbx.
* EFI_VARIABLE_APPEND_WRITE attribute must not be set in these cases.
*/
if (u16_strcmp(data, u"PK") && !null_key) {
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);
efi_free_pool(full_dp);
if (f)
EFI_CALL(f->close(f));
/* return to the parent menu */
ret = (ret == EFI_ABORTED) ? EFI_NOT_READY : ret;
return ret;
}
/**
* eficonfig_process_show_siglist() - show signature list content
*
* @data: pointer to the data for each entry
* Return: status code
*/
static efi_status_t eficonfig_process_show_siglist(void *data)
{
u32 i;
struct eficonfig_sig_data *sg = data;
puts(ANSI_CURSOR_HIDE);
puts(ANSI_CLEAR_CONSOLE);
printf(ANSI_CURSOR_POSITION, 1, 1);
printf("\n ** Show Signature Database (%ls) **\n\n"
" Owner GUID:\n"
" %pUL\n",
sg->varname, sg->esd->signature_owner.b);
for (i = 0; i < ARRAY_SIZE(sigtype_to_str); i++) {
if (!guidcmp(&sg->esl->signature_type, &sigtype_to_str[i].sig_type)) {
printf(" Signature Type:\n"
" %s\n", sigtype_to_str[i].str);
switch (sigtype_to_str[i].type) {
case SIG_TYPE_X509:
{
struct x509_certificate *cert_tmp;
cert_tmp = x509_cert_parse(sg->esd->signature_data,
sg->esl->signature_size);
printf(" Subject:\n"
" %s\n"
" Issuer:\n"
" %s\n",
cert_tmp->subject, cert_tmp->issuer);
break;
}
case SIG_TYPE_CRL:
{
u32 hash_size = sg->esl->signature_size - sizeof(efi_guid_t) -
sizeof(struct efi_time);
struct efi_time *time =
(struct efi_time *)((u8 *)sg->esd->signature_data +
hash_size);
printf(" ToBeSignedHash:\n");
print_hex_dump(" ", DUMP_PREFIX_NONE, 16, 1,
sg->esd->signature_data, hash_size, false);
printf(" TimeOfRevocation:\n"
" %d-%d-%d %02d:%02d:%02d\n",
time->year, time->month, time->day,
time->hour, time->minute, time->second);
break;
}
case SIG_TYPE_HASH:
{
u32 hash_size = sg->esl->signature_size - sizeof(efi_guid_t);
printf(" Hash:\n");
print_hex_dump(" ", DUMP_PREFIX_NONE, 16, 1,
sg->esd->signature_data, hash_size, false);
break;
}
default:
eficonfig_print_msg("ERROR! Unsupported format.");
return EFI_INVALID_PARAMETER;
}
}
}
while (tstc())
getchar();
printf("\n\n Press any key to continue");
getchar();
return EFI_SUCCESS;
}
/**
* prepare_signature_list_menu() - create the signature list menu entry
*
* @efimenu: pointer to the efimenu structure
* @varname: pointer to the variable name
* @db: pointer to the variable raw data
* @db_size: variable data size
* @func: callback of each entry
* Return: status code
*/
static efi_status_t prepare_signature_list_menu(struct efimenu *efi_menu, void *varname,
void *db, efi_uintn_t db_size,
eficonfig_entry_func func)
{
u32 num = 0;
efi_uintn_t size;
struct eficonfig_sig_data *sg;
struct efi_signature_list *esl;
struct efi_signature_data *esd;
efi_status_t ret = EFI_SUCCESS;
INIT_LIST_HEAD(&efi_menu->list);
esl = db;
size = db_size;
while (size > 0) {
u32 remain;
esd = (struct efi_signature_data *)((u8 *)esl +
(sizeof(struct efi_signature_list) +
esl->signature_header_size));
remain = esl->signature_list_size - sizeof(struct efi_signature_list) -
esl->signature_header_size;
for (; remain > 0; remain -= esl->signature_size) {
char buf[37];
char *title;
if (num >= EFICONFIG_ENTRY_NUM_MAX - 1) {
ret = EFI_OUT_OF_RESOURCES;
goto out;
}
sg = calloc(1, sizeof(struct eficonfig_sig_data));
if (!sg) {
ret = EFI_OUT_OF_RESOURCES;
goto err;
}
snprintf(buf, sizeof(buf), "%pUL", &esd->signature_owner);
title = strdup(buf);
if (!title) {
free(sg);
ret = EFI_OUT_OF_RESOURCES;
goto err;
}
sg->esl = esl;
sg->esd = esd;
sg->varname = varname;
ret = eficonfig_append_menu_entry(efi_menu, title, func, sg);
if (ret != EFI_SUCCESS) {
free(sg);
free(title);
goto err;
}
esd = (struct efi_signature_data *)((u8 *)esd + esl->signature_size);
num++;
}
size -= esl->signature_list_size;
esl = (struct efi_signature_list *)((u8 *)esl + esl->signature_list_size);
}
out:
ret = eficonfig_append_quit_entry(efi_menu);
err:
return ret;
}
/**
* enumerate_and_show_signature_database() - enumerate and show the signature database
*
* @data: pointer to the data for each entry
* Return: status code
*/
static efi_status_t enumerate_and_show_signature_database(void *varname)
{
void *db;
char buf[50];
efi_status_t ret;
efi_uintn_t db_size;
struct efimenu *efi_menu;
struct list_head *pos, *n;
struct eficonfig_entry *entry;
db = efi_get_var(varname, efi_auth_var_get_guid(varname), &db_size);
if (!db) {
eficonfig_print_msg("There is no entry in the signature database.");
return EFI_NOT_FOUND;
}
efi_menu = calloc(1, sizeof(struct efimenu));
if (!efi_menu) {
free(db);
return EFI_OUT_OF_RESOURCES;
}
ret = prepare_signature_list_menu(efi_menu, varname, db, db_size,
eficonfig_process_show_siglist);
if (ret != EFI_SUCCESS)
goto out;
snprintf(buf, sizeof(buf), " ** Show Signature Database (%ls) **", (u16 *)varname);
ret = eficonfig_process_common(efi_menu, buf);
out:
list_for_each_safe(pos, n, &efi_menu->list) {
entry = list_entry(pos, struct eficonfig_entry, list);
free(entry->data);
}
eficonfig_destroy(efi_menu);
free(db);
return ret;
}
/**
* eficonfig_process_show_signature_database() - process show signature database
*
* @data: pointer to the data for each entry
* Return: status code
*/
static efi_status_t eficonfig_process_show_signature_database(void *data)
{
efi_status_t ret;
while (1) {
ret = enumerate_and_show_signature_database(data);
if (ret != EFI_SUCCESS && ret != EFI_NOT_READY)
break;
}
/* 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},
{"Show Signature Database", eficonfig_process_show_signature_database},
{"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;
}