Hi,
The patch follows, as per discussion in email thread "Patch proposal
- mkimage: fit: Support signed conf 'auto' FITs". Let me know if you
prefer something to be changed, or patch to be split in several
commits.
I have updated the man page with description of the new feature and
examples. Also fixed some wrong or misleading information.
===
mkimage: fit: Support signed configurations in 'auto' FITs
Extend support for signing in auto-generated (-f auto) FIT. Previously,
it was possible to get signed 'images' subnodes in the FIT using
options -g and -o together with -f auto. This patch allows signing
'configurations' subnodes instead of 'images' ones (which are hashed),
using option -f auto-conf instead of -f auto. Adding also -K <dtb> and
-r options, will add public key to <dtb> file with required = "conf"
property.
Summary:
-f auto => FIT with crc32 images
-f auto -g ... -o ... => FIT with signed images
-f auto-conf -g ... -o ... => FIT with sha1 images and signed confs
Example: FIT with kernel, two device tree files, and signed
configurations; public key (needed to verify signatures) is
added to u-boot.dtb with required = "conf" property.
mkimage -f auto-conf -A arm -O linux -T kernel -C none -a 43e00000 \
-e 0 -d vmlinuz -b /path/to/first.dtb -b /path/to/second.dtb \
-k /folder/with/key-files -g keyname -o sha256,rsa4096 \
-K u-boot.dtb -r kernel.itb
Example: Add public key with required = "conf" property to u-boot.dtb
without needing to sign anything. This will also create a useless FIT
named unused.itb.
mkimage -f auto-conf -d /dev/null -k /folder/with/key-files \
-g keyname -o sha256,rsa4096 -K u-boot.dtb -r unused.itb
Signed-off-by: Massimo Pegorer <massimo.pego...@vimar.com>
---
doc/mkimage.1 | 119 ++++++++++++++++++++++++++++++++--------------
tools/fit_image.c | 75 +++++++++++++++++++----------
tools/imagetool.h | 10 +++-
tools/mkimage.c | 23 +++++++--
4 files changed, 160 insertions(+), 67 deletions(-)
diff --git a/doc/mkimage.1 b/doc/mkimage.1
index 353ea8b2f7..d8727ec73c 100644
--- a/doc/mkimage.1
+++ b/doc/mkimage.1
@@ -22,7 +22,8 @@ mkimage \- generate images for U-Boot
.SY mkimage
.RI [ option\~ .\|.\|.\&]
.BI \-f\~ image-tree-source-file\c
-.RB | auto
+.RB | auto\c
+.RB | auto-conf
.I image-file-name
.YS
.
@@ -296,9 +297,9 @@ FIT. See
for details on using external data.
.
.TP
-\fB\-f \fIimage-tree-source-file\fR | \fBauto
+\fB\-f \fIimage-tree-source-file\fR | \fBauto\fR | \fBauto-conf
.TQ
-\fB\-\-fit \fIimage-tree-source-file\fR | \fBauto
+\fB\-\-fit \fIimage-tree-source-file\fR | \fBauto\fR | \fBauto-conf
Image tree source file that describes the structure and contents of the
FIT image.
.IP
@@ -317,7 +318,25 @@ and
options may be used to specify the image to include in the FIT and its
attributes. No
.I image-tree-source-file
-is required.
+is required. The
+.BR \-g ,
+.BR \-o ,
+and
+.B \-k
+or
+.B \-G
+options may be used to get \(oqimages\(cq signed subnodes in the generated
+auto FIT. Instead, to get \(oqconfigurations\(cq signed subnodes and
+\(oqimages\(cq hashed subnodes, pass
+.BR "\-f auto-conf".
+In this case
+.BR \-g ,
+.BR \-o ,
+and
+.B \-k
+or
+.B \-G
+are mandatory options.
.
.TP
.B \-F
@@ -348,16 +367,16 @@ for use with signing, and a certificate
necessary when embedding it into another device tree using
.BR \-K .
.I name
-defaults to the value of the signature node's \(oqkey-name-hint\(cq property,
-but may be overridden using
-.BR \-g .
+is the value of the signature node's \(oqkey-name-hint\(cq property.
.
.TP
.BI \-G " key-file"
.TQ
.BI \-\-key\-file " key-file"
Specifies the private key file to use when signing. This option may be used
-instead of \-k.
+instead of \-k. Useful when the private key file basename does not match
+\(oqkey-name-hint\(cq value. But note that it may lead to unexpected results
+when used together with -K and/or -k options.
.
.TP
.BI \-K " key-destination"
@@ -373,49 +392,50 @@ CONFIG_OF_CONTROL in U-Boot.
.BI \-g " key-name-hint"
.TQ
.BI \-\-key\-name\-hint " key-name-hint"
-Overrides the signature node's \(oqkey-name-hint\(cq property. This is
-especially useful when signing an image with
-.BR "\-f auto" .
-This is the
-.I name
-part of the key. The directory part is set by
-.BR \-k .
-This option also indicates that the images included in the FIT should be
signed.
-If this option is specified, then
+Specifies the value of signature node \(oqkey-name-hint\(cq property for
+an automatically generated FIT image. It makes sense only when used with
+.B "\-f auto"
+or
+.BR "\-f auto-conf".
+This option also indicates that the images or configurations included in
+the FIT should be signed. If this option is specified, then
.B \-o
must be specified as well.
.
.TP
-.BI \-o " crypto" , checksum
+.BI \-o " checksum" , crypto
.TQ
-.BI \-\-algo " crypto" , checksum
-Specifies the algorithm to be used for signing a FIT image. The default is
-taken from the signature node's \(oqalgo\(cq property.
+.BI \-\-algo " checksum" , crypto
+Specifies the algorithm to be used for signing a FIT image, overriding value
+taken from the signature node \(oqalgo\(cq property in the
+.IR image-tree-source-file .
+It is mandatory for automatically generated FIT.
+.IP
The valid values for
-.I crypto
+.I checksum
are:
.RS
.IP
.TS
lb.
-rsa2048
-rsa3072
-rsa4096
-ecdsa256
+sha1
+sha256
+sha384
+sha512
.TE
.RE
.IP
The valid values for
-.I checksum
-are
+.I crypto
+are:
.RS
.IP
.TS
lb.
-sha1
-sha256
-sha384
-sha512
+rsa2048
+rsa3072
+rsa4096
+ecdsa256
.TE
.RE
.
@@ -423,9 +443,13 @@ sha512
.B \-r
.TQ
.B \-\-key\-required
-Specifies that keys used to sign the FIT are required. This means that they
-must be verified for the image to boot. Without this option, the verification
-will be optional (useful for testing but not for release).
+Specifies that keys used to sign the FIT are required. This means that images
+or configurations signatures must be verified before using them (i.e. to
+boot). Without this option, the verification will be optional (useful for
+testing but not for release). It makes sense only when used with
+.BR \-K.
+When both, images and configurations, are signed, \(oqrequired\(cq property
+value will be "conf".
.
.TP
.BI \-N " engine"
@@ -716,7 +740,7 @@ skipping those for which keys cannot be found. Also add a
comment.
.EE
.RE
.P
-Add public keys to u\-boot.dtb without needing a FIT to sign. This will also
+Add public key to u\-boot.dtb without needing a FIT to sign. This will also
create a FIT containing an images node with no data named unused.itb.
.RS
.P
@@ -726,6 +750,16 @@ create a FIT containing an images node with no data named
unused.itb.
.EE
.RE
.P
+Add public key with required = "conf" property to u\-boot.dtb without needing
+a FIT to sign. This will also create a useless FIT named unused.itb.
+.RS
+.P
+.EX
+\fBmkimage \-f auto-conf \-d /dev/null \-k /public/signing\-keys \-g dev \\
+ \-o sha256,rsa2048 \-K u\-boot.dtb -r unused.itb
+.EE
+.RE
+.P
Update an existing FIT image, signing it with additional keys.
Add corresponding public keys into u\-boot.dtb. This will resign all images
with keys that are available in the new directory. Images that request signing
@@ -768,6 +802,19 @@ file is required.
\-d vmlinuz \-k /secret/signing\-keys \-g dev \-o sha256,rsa2048
kernel.itb
.EE
.RE
+.P
+Create a FIT image containing a kernel and some device tree files, signing
+each configuration, using automatic mode. Moreover, the public key needed to
+verify signatures is added to u\-boot.dtb with required = "conf" property.
+.RS
+.P
+.EX
+\fBmkimage \-f auto-conf \-A arm \-O linux \-T kernel \-C none \-a 43e00000 \\
+ \-e 0 \-d vmlinuz \-b /path/to/file\-1.dtb \-b /path/to/file\-2.dtb \\
+ \-k /folder/with/signing\-keys \-g dev \-o sha256,rsa2048 \\
+ \-K u\-boot.dtb -r kernel.itb
+.EE
+.RE
.
.SH SEE ALSO
.BR dtc (1),
diff --git a/tools/fit_image.c b/tools/fit_image.c
index 923a9755b7..d15a377779 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -199,36 +199,59 @@ static void get_basename(char *str, int size, const char
*fname)
}
/**
- * add_hash_node() - Add a hash or signature node
+ * fit_add_hash_or_sign() - Add a hash or signature node
*
* @params: Image parameters
* @fdt: Device tree to add to (in sequential-write mode)
+ * @is_images_subnode: 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.
- *
- * Return: 0 on success, or -1 on failure
+ * 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.
*/
-static int add_hash_node(struct image_tool_params *params, void *fdt)
+static void fit_add_hash_or_sign(struct image_tool_params *params, void *fdt,
+ bool is_images_subnode)
{
- if (params->keyname) {
- if (!params->algo_name) {
- fprintf(stderr,
- "%s: Algorithm name must be specified\n",
- params->cmdname);
- return -1;
+ const char *hash_algo = "crc32";
+ bool do_hash = false;
+ bool do_sign = false;
+
+ switch (params->auto_fit) {
+ case AF_OFF:
+ break;
+ case AF_HASHED_IMG:
+ do_hash = is_images_subnode;
+ break;
+ case AF_SIGNED_IMG:
+ do_sign = is_images_subnode;
+ break;
+ case AF_SIGNED_CONF:
+ if (is_images_subnode) {
+ do_hash = true;
+ hash_algo = "sha1";
+ } else {
+ do_sign = true;
}
+ break;
+ default:
+ fprintf(stderr,
+ "%s: Unsupported auto FIT mode %u\n",
+ params->cmdname, params->auto_fit);
+ break;
+ }
+
+ if (do_hash) {
+ fdt_begin_node(fdt, FIT_HASH_NODENAME);
+ fdt_property_string(fdt, FIT_ALGO_PROP, hash_algo);
+ fdt_end_node(fdt);
+ }
- fdt_begin_node(fdt, "signature-1");
+ if (do_sign) {
+ fdt_begin_node(fdt, FIT_SIG_NODENAME);
fdt_property_string(fdt, FIT_ALGO_PROP, params->algo_name);
fdt_property_string(fdt, FIT_KEY_HINT, params->keyname);
- } else {
- fdt_begin_node(fdt, "hash-1");
- fdt_property_string(fdt, FIT_ALGO_PROP, "crc32");
+ fdt_end_node(fdt);
}
-
- fdt_end_node(fdt);
- return 0;
}
/**
@@ -269,9 +292,7 @@ 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);
- if (ret)
- return ret;
+ fit_add_hash_or_sign(params, fdt, true);
fdt_end_node(fdt);
/* Now the device tree files if available */
@@ -294,7 +315,7 @@ 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);
+ fit_add_hash_or_sign(params, fdt, true);
if (ret)
return ret;
fdt_end_node(fdt);
@@ -314,7 +335,7 @@ 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);
+ fit_add_hash_or_sign(params, fdt, true);
if (ret)
return ret;
fdt_end_node(fdt);
@@ -366,6 +387,7 @@ 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);
+ fit_add_hash_or_sign(params, fdt, false);
fdt_end_node(fdt);
}
@@ -378,6 +400,7 @@ 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");
+ fit_add_hash_or_sign(params, fdt, false);
fdt_end_node(fdt);
}
@@ -721,7 +744,7 @@ static int fit_handle_file(struct image_tool_params *params)
sprintf (tmpfile, "%s%s", params->imagefile, MKIMAGE_TMPFILE_SUFFIX);
/* We either compile the source file, or use the existing FIT image */
- if (params->auto_its) {
+ if (params->auto_fit) {
if (fit_build(params, tmpfile)) {
fprintf(stderr, "%s: failed to build FIT\n",
params->cmdname);
@@ -905,7 +928,7 @@ static int fit_extract_contents(void *ptr, struct
image_tool_params *params)
static int fit_check_params(struct image_tool_params *params)
{
- if (params->auto_its)
+ if (params->auto_fit)
return 0;
return ((params->dflag && params->fflag) ||
(params->fflag && params->lflag) ||
diff --git a/tools/imagetool.h b/tools/imagetool.h
index ca7c2e48ba..fdceea46c0 100644
--- a/tools/imagetool.h
+++ b/tools/imagetool.h
@@ -39,6 +39,14 @@ struct content_info {
const char *fname;
};
+/* FIT auto generation modes */
+enum af_mode {
+ AF_OFF = 0, /* Needs .its or existing FIT to be provided */
+ AF_HASHED_IMG, /* Auto FIT with crc32 hashed images subnodes */
+ AF_SIGNED_IMG, /* Auto FIT with signed images subnodes */
+ AF_SIGNED_CONF, /* Auto FIT with sha1 images and signed configs */
+};
+
/*
* This structure defines all such variables those are initialized by
* mkimage and dumpimage main core and need to be referred by image
@@ -79,7 +87,7 @@ struct image_tool_params {
int require_keys; /* 1 to mark signing keys as 'required' */
int file_size; /* Total size of output file */
int orig_file_size; /* Original size for file before padding */
- bool auto_its; /* Automatically create the .its file */
+ enum af_mode auto_fit; /* Automatically create the FIT */
int fit_image_type; /* Image type to put into the FIT */
char *fit_ramdisk; /* Ramdisk file to include */
struct content_info *content_head; /* List of files to include */
diff --git a/tools/mkimage.c b/tools/mkimage.c
index 30c6df7708..75b72420b9 100644
--- a/tools/mkimage.c
+++ b/tools/mkimage.c
@@ -104,7 +104,7 @@ static void usage(const char *msg)
" -v ==> verbose\n",
params.cmdname);
fprintf(stderr,
- " %s [-D dtc_options] [-f fit-image.its|-f auto|-F] [-b
<dtb> [-b <dtb>]] [-E] [-B size] [-i <ramdisk.cpio.gz>] fit-image\n"
+ " %s [-D dtc_options] [-f fit-image.its|-f auto|-f
auto-conf|-F] [-b <dtb> [-b <dtb>]] [-E] [-B size] [-i <ramdisk.cpio.gz>]
fit-image\n"
" <dtb> file is used with -f auto, it may occur
multiple times.\n",
params.cmdname);
fprintf(stderr,
@@ -271,7 +271,10 @@ static void process_args(int argc, char **argv)
break;
case 'f':
datafile = optarg;
- params.auto_its = !strcmp(datafile, "auto");
+ if (!strcmp(datafile, "auto"))
+ params.auto_fit = AF_HASHED_IMG;
+ else if (!strcmp(datafile, "auto-conf"))
+ params.auto_fit = AF_SIGNED_CONF;
/* fallthrough */
case 'F':
/*
@@ -283,6 +286,7 @@ static void process_args(int argc, char **argv)
break;
case 'g':
params.keyname = optarg;
+ break;
case 'G':
params.keyfile = optarg;
break;
@@ -370,6 +374,17 @@ static void process_args(int argc, char **argv)
if (optind < argc)
params.imagefile = argv[optind];
+ if (params.auto_fit == AF_SIGNED_CONF) {
+ if (!params.keyname || !params.algo_name)
+ usage("Auto FIT with signed configs requires -f
auto-conf "
+ "-g <key name hint> -o <algorithm>");
+ } else if (params.auto_fit == AF_HASHED_IMG && params.keyname) {
+ params.auto_fit = AF_SIGNED_IMG;
+ if (!params.algo_name)
+ usage("Auto FIT with signed images requires -f auto "
+ "-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
@@ -377,8 +392,8 @@ static void process_args(int argc, char **argv)
*/
if (params.type == IH_TYPE_FLATDT) {
params.fit_image_type = type ? type : IH_TYPE_KERNEL;
- /* For auto_its, datafile is always 'auto' */
- if (!params.auto_its)
+ /* For auto-FIT, datafile has to be provided with -d */
+ if (!params.auto_fit)
params.datafile = datafile;
else if (!params.datafile)
usage("Missing data file for auto-FIT (use -d)");
--
2.34.1
