Commit 87b0af9317cb4105f3f29cb0a4c28c7cd87ea65f added support for signing
auto-generated (mkimage -f auto) FIT. Unfortunately, this signs 'images'
subnodes but not 'configurations' ones. Following patch is a proposal to
support also 'configurations' signing + 'images' hashing, as an alternative to
'images' signing, with 'auto' FIT. For this purpose, a new optional argument is
added to mkimage '-r' option: any other better idea?
=====
>From 8c8c8f421d541cc2eccb50490a57e86b81dc8df2 Mon Sep 17 00:00:00 2001
From: Massimo Pegorer <massimo.pego...@vimar.com>
Date: Sat, 19 Nov 2022 16:25:58 +0100
Subject: [PATCH] mkimage: fit: Support signed conf 'auto' FITs
Extend support for signing in auto-generated FITs. Previously, it was
possible to sign 'images' subnodes in auto FIT, but not 'configurations'
subnodes. Consequently, usage with -K and -r options (i.e. write keys as
'required' in a .dtb file) resulted in adding a signature node with
required = "image" property in the dtb.
This patch allows usage of an optional argument with -r option to select
which subnodes, 'images' ones or 'configurations' ones, have to be signed
(in the second case 'images' subnodes are hashed): with '-r' or '-rimage'
the firsts are signed, while with '-rconf' the seconds; argument values
different than 'image' and 'conf' are invalid.
Example to write a key with required = "conf" attribute into a dtb file:
mkimage -f auto -rconf -d /dev/null -K <dtb-file> -o <algo> \
-g <key-name-hint> -k <path-to-key-file> <dummy-itb-file>
Signed-off-by: Massimo Pegorer <massimo.pego...@vimar.com>
---
tools/fit_image.c | 25 +++++++++++++++++--------
tools/mkimage.c | 18 ++++++++++++++----
2 files changed, 31 insertions(+), 12 deletions(-)
diff --git a/tools/fit_image.c b/tools/fit_image.c
index 923a9755b7..c78d83d509 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -199,19 +199,22 @@ static void get_basename(char *str, int size, const char
*fname)
}
/**
- * add_hash_node() - Add a hash or signature node
+ * add_hash_or_sign_node() - Add a hash or signature node
*
* @params: Image parameters
* @fdt: Device tree to add to (in sequential-write mode)
+ * @do_add_hash: true to add hash even if key name hint is provided
*
- * If there is a key name hint, try to sign the images. Otherwise, just add a
- * CRC.
+ * If do_add_hash is false (default) and there is a key name hint, try to add
+ * a sign node to parent. Otherwise, just add a CRC. Rationale: if conf have
+ * to be signed, image/dt have to be hashed even if there is a key name hint.
*
* Return: 0 on success, or -1 on failure
*/
-static int add_hash_node(struct image_tool_params *params, void *fdt)
+static int add_hash_or_sig_node(struct image_tool_params *params, void *fdt,
+ bool do_add_hash)
{
- if (params->keyname) {
+ if (!do_add_hash && params->keyname) {
if (!params->algo_name) {
fprintf(stderr,
"%s: Algorithm name must be specified\n",
@@ -269,7 +272,7 @@ static int fit_write_images(struct image_tool_params
*params, char *fdt)
ret = fdt_property_file(params, fdt, FIT_DATA_PROP, params->datafile);
if (ret)
return ret;
- ret = add_hash_node(params, fdt);
+ ret = add_hash_or_sig_node(params, fdt, (params->require_keys == 2));
if (ret)
return ret;
fdt_end_node(fdt);
@@ -294,7 +297,8 @@ static int fit_write_images(struct image_tool_params
*params, char *fdt)
genimg_get_arch_short_name(params->arch));
fdt_property_string(fdt, FIT_COMP_PROP,
genimg_get_comp_short_name(IH_COMP_NONE));
- ret = add_hash_node(params, fdt);
+ ret = add_hash_or_sig_node(params, fdt,
+ (params->require_keys == 2));
if (ret)
return ret;
fdt_end_node(fdt);
@@ -314,7 +318,8 @@ static int fit_write_images(struct image_tool_params
*params, char *fdt)
params->fit_ramdisk);
if (ret)
return ret;
- ret = add_hash_node(params, fdt);
+ ret = add_hash_or_sig_node(params, fdt,
+ (params->require_keys == 2));
if (ret)
return ret;
fdt_end_node(fdt);
@@ -366,6 +371,8 @@ static void fit_write_configs(struct image_tool_params
*params, char *fdt)
snprintf(str, sizeof(str), FIT_FDT_PROP "-%d", upto);
fdt_property_string(fdt, FIT_FDT_PROP, str);
+ if (params->require_keys == 2)
+ add_hash_or_sig_node(params, fdt, false);
fdt_end_node(fdt);
}
@@ -378,6 +385,8 @@ static void fit_write_configs(struct image_tool_params
*params, char *fdt)
if (params->fit_ramdisk)
fdt_property_string(fdt, FIT_RAMDISK_PROP,
FIT_RAMDISK_PROP "-1");
+ if (params->require_keys == 2)
+ add_hash_or_sig_node(params, fdt, false);
fdt_end_node(fdt);
}
diff --git a/tools/mkimage.c b/tools/mkimage.c
index 30c6df7708..4d4f128b54 100644
--- a/tools/mkimage.c
+++ b/tools/mkimage.c
@@ -125,7 +125,7 @@ static void usage(const char *msg)
" -c => add comment in signature node\n"
" -F => re-sign existing FIT image\n"
" -p => place external data at a static position\n"
- " -r => mark keys used as 'required' in dtb\n"
+ " -r => mark keys used as 'required' in dtb (-rconf
for 'auto' FIT with signed config)\n"
" -N => openssl engine to use for signing\n"
" -o => algorithm to use for signing\n");
#else
@@ -159,7 +159,7 @@ static int add_content(int type, const char *fname)
}
static const char optstring[] =
- "a:A:b:B:c:C:d:D:e:Ef:Fg:G:i:k:K:ln:N:o:O:p:qrR:stT:vVx";
+ "a:A:b:B:c:C:d:D:e:Ef:Fg:G:i:k:K:ln:N:o:O:p:qr::R:stT:vVx";
static const struct option longopts[] = {
{ "load-address", required_argument, NULL, 'a' },
@@ -187,7 +187,7 @@ static const struct option longopts[] = {
{ "os", required_argument, NULL, 'O' },
{ "position", required_argument, NULL, 'p' },
{ "quiet", no_argument, NULL, 'q' },
- { "key-required", no_argument, NULL, 'r' },
+ { "key-required", optional_argument, NULL, 'r' },
{ "secondary-config", required_argument, NULL, 'R' },
{ "no-copy", no_argument, NULL, 's' },
{ "touch", no_argument, NULL, 't' },
@@ -326,7 +326,12 @@ static void process_args(int argc, char **argv)
params.quiet = 1;
break;
case 'r':
- params.require_keys = 1;
+ if (!optarg || !strcmp(optarg, "image"))
+ params.require_keys = 1;
+ else if (!strcmp(optarg, "conf"))
+ params.require_keys = 2;
+ else
+ usage("Invalid key-required option argument");
break;
case 'R':
/*
@@ -370,6 +375,11 @@ static void process_args(int argc, char **argv)
if (optind < argc)
params.imagefile = argv[optind];
+ if (params.require_keys == 2)
+ if (!params.auto_its || !params.keyname || !params.algo_name)
+ usage("Auto FIT with signed config requires -f auto "
+ "-rconf -g <key name hint> -o <algorithm>");
+
/*
* For auto-generated FIT images we need to know the image type to put
* in the FIT, which is separate from the file's image type (which
--
2.34.1
