request confirmation before booting an unsigned image
with a default timeout
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx>
---
commands/go.c | 9 +++++++--
common/Kconfig | 8 ++++++++
common/boot_verify.c | 47 ++++++++++++++++++++++++++++++++++++++++++++---
common/bootm.c | 6 ++++++
common/image-fit.c | 1 +
common/uimage.c | 1 +
include/boot_verify.h | 7 +++++++
7 files changed, 74 insertions(+), 5 deletions(-)
diff --git a/commands/go.c b/commands/go.c
index e0385a977..919bcddc7 100644
--- a/commands/go.c
+++ b/commands/go.c
@@ -38,8 +38,13 @@ static int do_go(int argc, char *argv[])
if (argc < 2)
return COMMAND_ERROR_USAGE;
- if (boot_get_verify_mode() < BOOT_VERIFY_AVAILABLE)
- return -ESECVIOLATION;
+ if (boot_get_verify_mode() < BOOT_VERIFY_AVAILABLE) {
+ int is_sec;
+
+ is_sec = boot_can_start_unsigned();
+ if (is_sec)
+ return is_sec;
+ }
if (!isdigit(*argv[1])) {
fd = open(argv[1], O_RDONLY);
diff --git a/common/Kconfig b/common/Kconfig
index 00e98e859..2588651ae 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -648,6 +648,14 @@ config BOOT_FORCE_SIGNED_IMAGES
are refused to boot. Effectively this means only Signed images can
be booted.
+config BOOT_FORCE_USER_SIGNED_IMAGES
+ bool
+ prompt "Force booting of signed images or confirm them"
+ depends on HAS_SECURE_BOOT
+ help
+ With this option enabled only signed images can be booted, unsigned images
+ need a user confirmation to boot.
+
config BLSPEC
depends on BLOCK
depends on FLEXIBLE_BOOTARGS
diff --git a/common/boot_verify.c b/common/boot_verify.c
index 9cbeb7a65..07ae07e16 100644
--- a/common/boot_verify.c
+++ b/common/boot_verify.c
@@ -1,9 +1,17 @@
+/*
+ * Copyright (c) 2016 Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>, Pengutronix
+ * Copyright (c) 2017 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx>
+ *
+ * Under GPLv2 Only
+ */
#include <common.h>
#include <boot_verify.h>
+#include <console_countdown.h>
#include <globalvar.h>
#include <magicvar.h>
#include <init.h>
+static unsigned int boot_verify_confirm_timeout = 10;
static enum boot_verify boot_verify_mode = BOOT_VERIFY_HASH;
enum boot_verify boot_get_verify_mode(void)
@@ -14,6 +22,7 @@ enum boot_verify boot_get_verify_mode(void)
/* keep it for the most secure to the less */
static const char * const boot_verify_names[] = {
[BOOT_VERIFY_SIGNATURE] = "signature",
+ [BOOT_VERIFY_SIGNATURE_USER] = "signature-user",
[BOOT_VERIFY_AVAILABLE] = "available",
[BOOT_VERIFY_HASH] = "hash",
[BOOT_VERIFY_NONE] = "none",
@@ -40,6 +49,29 @@ void boot_set_is_secure_mode(int (*fn)(void))
__is_secure_mode = fn;
}
+int boot_can_start_unsigned(void)
+{
+ int ret;
+ char c;
+ int timeout = boot_verify_confirm_timeout;
+
+ if (!is_secure_mode())
+ return 0;
+
+ if (boot_verify_mode != BOOT_VERIFY_SIGNATURE_USER)
+ return -ESECVIOLATION;
+
+ printf("Are you sure you wish to run an unsigned binary\n");
+ printf("in a secure environment?\n");
+ printf("press y to confirm\n");
+
+ ret = console_countdown(timeout, CONSOLE_COUNTDOWN_ANYKEY, &c);
+ if (ret != -EINTR)
+ return -ESECVIOLATION;
+
+ return c == 'y' ? 0 : -ESECVIOLATION;
+}
+
static int init_boot_verify(void)
{
int size;
@@ -47,16 +79,25 @@ static int init_boot_verify(void)
if (IS_ENABLED(CONFIG_BOOT_FORCE_SIGNED_IMAGES))
boot_verify_mode = BOOT_VERIFY_SIGNATURE;
- if (is_secure_mode())
- size = 1;
- else
+ if (is_secure_mode()) {
+ if (IS_ENABLED(CONFIG_BOOT_FORCE_USER_SIGNED_IMAGES))
+ size = 2;
+ else
+ size = 1;
+ } else {
size = ARRAY_SIZE(boot_verify_names);
+ }
globalvar_add_simple_enum("boot.verify", (unsigned int *)&boot_verify_mode,
boot_verify_names, size);
+ globalvar_add_simple_int("boot.verify_confirm_timeout",
+ &boot_verify_confirm_timeout, "%u");
+
return 0;
}
late_initcall(init_boot_verify);
BAREBOX_MAGICVAR_NAMED(global_boot_verify, global.boot.verify, "boot default verify level");
+BAREBOX_MAGICVAR_NAMED(global_boot_verify_confirm_timeout, global.boot.verify_confirm_timeout,
+ "Secure Boot Comfirm timeout in seconds before booting an unsigned image");
diff --git a/common/bootm.c b/common/bootm.c
index 1558f3c5d..73a3a99dd 100644
--- a/common/bootm.c
+++ b/common/bootm.c
@@ -579,6 +579,12 @@ int bootm_boot(struct bootm_data *bootm_data)
printf("Passing control to %s handler\n", handler->name);
}
+ if (!handler->is_secure_supported && is_secure_mode()) {
+ ret = boot_can_start_unsigned();
+ if (ret)
+ goto err_out;
+ }
+
ret = handler->bootm(data);
if (data->dryrun)
printf("Dryrun. Aborted\n");
diff --git a/common/image-fit.c b/common/image-fit.c
index 53f3173fc..0df735062 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -465,6 +465,7 @@ static int fit_config_verify_signature(struct fit_handle *handle, struct device_
case BOOT_VERIFY_HASH:
return 0;
case BOOT_VERIFY_SIGNATURE:
+ case BOOT_VERIFY_SIGNATURE_USER:
ret = -EINVAL;
break;
case BOOT_VERIFY_AVAILABLE:
diff --git a/common/uimage.c b/common/uimage.c
index d1947aa11..f25341c15 100644
--- a/common/uimage.c
+++ b/common/uimage.c
@@ -30,6 +30,7 @@
#include <rtc.h>
#include <filetype.h>
#include <memory.h>
+#include <bootm.h>
static inline int uimage_is_multi_image(struct uimage_handle *handle)
{
diff --git a/include/boot_verify.h b/include/boot_verify.h
index ee830bf5c..12dcfbfdc 100644
--- a/include/boot_verify.h
+++ b/include/boot_verify.h
@@ -3,6 +3,7 @@
enum boot_verify {
BOOT_VERIFY_SIGNATURE,
+ BOOT_VERIFY_SIGNATURE_USER,
BOOT_VERIFY_AVAILABLE,
BOOT_VERIFY_HASH,
BOOT_VERIFY_NONE,
@@ -19,10 +20,16 @@ static int inline is_secure_mode(void)
return 0;
}
+static int inline boot_can_start_unsigned(void)
+{
+ return 0;
+}
+
static void inline boot_set_is_secure_mode(int (*fn)(void)) {}
#else
enum boot_verify boot_get_verify_mode(void);
int is_secure_mode(void);
+int boot_can_start_unsigned(void);
void boot_set_is_secure_mode(int (*fn)(void));
#endif
--
2.11.0
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