blob: 5d907cfc42c66b3a4971bc00c24771a7420a9a2a [file] [log] [blame]
/*
* Copyright (c) 2013, Google Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#ifdef USE_HOSTCC
#include "mkimage.h"
#include <time.h>
#else
#include <common.h>
#include <malloc.h>
DECLARE_GLOBAL_DATA_PTR;
#endif /* !USE_HOSTCC*/
#include <image.h>
#include <rsa.h>
#define IMAGE_MAX_HASHED_NODES 100
struct image_sig_algo image_sig_algos[] = {
{
"sha1,rsa2048",
rsa_sign,
rsa_add_verify_data,
rsa_verify,
}
};
struct image_sig_algo *image_get_sig_algo(const char *name)
{
int i;
for (i = 0; i < ARRAY_SIZE(image_sig_algos); i++) {
if (!strcmp(image_sig_algos[i].name, name))
return &image_sig_algos[i];
}
return NULL;
}
/**
* fit_region_make_list() - Make a list of image regions
*
* Given a list of fdt_regions, create a list of image_regions. This is a
* simple conversion routine since the FDT and image code use different
* structures.
*
* @fit: FIT image
* @fdt_regions: Pointer to FDT regions
* @count: Number of FDT regions
* @region: Pointer to image regions, which must hold @count records. If
* region is NULL, then (except for an SPL build) the array will be
* allocated.
* @return: Pointer to image regions
*/
struct image_region *fit_region_make_list(const void *fit,
struct fdt_region *fdt_regions, int count,
struct image_region *region)
{
int i;
debug("Hash regions:\n");
debug("%10s %10s\n", "Offset", "Size");
/*
* Use malloc() except in SPL (to save code size). In SPL the caller
* must allocate the array.
*/
#ifndef CONFIG_SPL_BUILD
if (!region)
region = calloc(sizeof(*region), count);
#endif
if (!region)
return NULL;
for (i = 0; i < count; i++) {
debug("%10x %10x\n", fdt_regions[i].offset,
fdt_regions[i].size);
region[i].data = fit + fdt_regions[i].offset;
region[i].size = fdt_regions[i].size;
}
return region;
}
static int fit_image_setup_verify(struct image_sign_info *info,
const void *fit, int noffset, int required_keynode,
char **err_msgp)
{
char *algo_name;
if (fit_image_hash_get_algo(fit, noffset, &algo_name)) {
*err_msgp = "Can't get hash algo property";
return -1;
}
memset(info, '\0', sizeof(*info));
info->keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL);
info->fit = (void *)fit;
info->node_offset = noffset;
info->algo = image_get_sig_algo(algo_name);
info->fdt_blob = gd_fdt_blob();
info->required_keynode = required_keynode;
printf("%s:%s", algo_name, info->keyname);
if (!info->algo) {
*err_msgp = "Unknown signature algorithm";
return -1;
}
return 0;
}
int fit_image_check_sig(const void *fit, int noffset, const void *data,
size_t size, int required_keynode, char **err_msgp)
{
struct image_sign_info info;
struct image_region region;
uint8_t *fit_value;
int fit_value_len;
*err_msgp = NULL;
if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
err_msgp))
return -1;
if (fit_image_hash_get_value(fit, noffset, &fit_value,
&fit_value_len)) {
*err_msgp = "Can't get hash value property";
return -1;
}
region.data = data;
region.size = size;
if (info.algo->verify(&info, &region, 1, fit_value, fit_value_len)) {
*err_msgp = "Verification failed";
return -1;
}
return 0;
}
static int fit_image_verify_sig(const void *fit, int image_noffset,
const char *data, size_t size, const void *sig_blob,
int sig_offset)
{
int noffset;
char *err_msg = "";
int verified = 0;
int ret;
/* Process all hash subnodes of the component image node */
for (noffset = fdt_first_subnode(fit, image_noffset);
noffset >= 0;
noffset = fdt_next_subnode(fit, noffset)) {
const char *name = fit_get_name(fit, noffset, NULL);
if (!strncmp(name, FIT_SIG_NODENAME,
strlen(FIT_SIG_NODENAME))) {
ret = fit_image_check_sig(fit, noffset, data,
size, -1, &err_msg);
if (ret) {
puts("- ");
} else {
puts("+ ");
verified = 1;
break;
}
}
}
if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
err_msg = "Corrupted or truncated tree";
goto error;
}
return verified ? 0 : -EPERM;
error:
printf(" error!\n%s for '%s' hash node in '%s' image node\n",
err_msg, fit_get_name(fit, noffset, NULL),
fit_get_name(fit, image_noffset, NULL));
return -1;
}
int fit_image_verify_required_sigs(const void *fit, int image_noffset,
const char *data, size_t size, const void *sig_blob,
int *no_sigsp)
{
int verify_count = 0;
int noffset;
int sig_node;
/* Work out what we need to verify */
*no_sigsp = 1;
sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
if (sig_node < 0) {
debug("%s: No signature node found: %s\n", __func__,
fdt_strerror(sig_node));
return 0;
}
for (noffset = fdt_first_subnode(sig_blob, sig_node);
noffset >= 0;
noffset = fdt_next_subnode(sig_blob, noffset)) {
const char *required;
int ret;
required = fdt_getprop(sig_blob, noffset, "required", NULL);
if (!required || strcmp(required, "image"))
continue;
ret = fit_image_verify_sig(fit, image_noffset, data, size,
sig_blob, noffset);
if (ret) {
printf("Failed to verify required signature '%s'\n",
fit_get_name(sig_blob, noffset, NULL));
return ret;
}
verify_count++;
}
if (verify_count)
*no_sigsp = 0;
return 0;
}
int fit_config_check_sig(const void *fit, int noffset, int required_keynode,
char **err_msgp)
{
char * const exc_prop[] = {"data"};
const char *prop, *end, *name;
struct image_sign_info info;
const uint32_t *strings;
uint8_t *fit_value;
int fit_value_len;
int max_regions;
int i, prop_len;
char path[200];
int count;
debug("%s: fdt=%p, conf='%s', sig='%s'\n", __func__, gd_fdt_blob(),
fit_get_name(fit, noffset, NULL),
fit_get_name(gd_fdt_blob(), required_keynode, NULL));
*err_msgp = NULL;
if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
err_msgp))
return -1;
if (fit_image_hash_get_value(fit, noffset, &fit_value,
&fit_value_len)) {
*err_msgp = "Can't get hash value property";
return -1;
}
/* Count the number of strings in the property */
prop = fdt_getprop(fit, noffset, "hashed-nodes", &prop_len);
end = prop ? prop + prop_len : prop;
for (name = prop, count = 0; name < end; name++)
if (!*name)
count++;
if (!count) {
*err_msgp = "Can't get hashed-nodes property";
return -1;
}
/* Add a sanity check here since we are using the stack */
if (count > IMAGE_MAX_HASHED_NODES) {
*err_msgp = "Number of hashed nodes exceeds maximum";
return -1;
}
/* Create a list of node names from those strings */
char *node_inc[count];
debug("Hash nodes (%d):\n", count);
for (name = prop, i = 0; name < end; name += strlen(name) + 1, i++) {
debug(" '%s'\n", name);
node_inc[i] = (char *)name;
}
/*
* Each node can generate one region for each sub-node. Allow for
* 7 sub-nodes (hash@1, signature@1, etc.) and some extra.
*/
max_regions = 20 + count * 7;
struct fdt_region fdt_regions[max_regions];
/* Get a list of regions to hash */
count = fdt_find_regions(fit, node_inc, count,
exc_prop, ARRAY_SIZE(exc_prop),
fdt_regions, max_regions - 1,
path, sizeof(path), 0);
if (count < 0) {
*err_msgp = "Failed to hash configuration";
return -1;
}
if (count == 0) {
*err_msgp = "No data to hash";
return -1;
}
if (count >= max_regions - 1) {
*err_msgp = "Too many hash regions";
return -1;
}
/* Add the strings */
strings = fdt_getprop(fit, noffset, "hashed-strings", NULL);
if (strings) {
fdt_regions[count].offset = fdt_off_dt_strings(fit) +
fdt32_to_cpu(strings[0]);
fdt_regions[count].size = fdt32_to_cpu(strings[1]);
count++;
}
/* Allocate the region list on the stack */
struct image_region region[count];
fit_region_make_list(fit, fdt_regions, count, region);
if (info.algo->verify(&info, region, count, fit_value,
fit_value_len)) {
*err_msgp = "Verification failed";
return -1;
}
return 0;
}
static int fit_config_verify_sig(const void *fit, int conf_noffset,
const void *sig_blob, int sig_offset)
{
int noffset;
char *err_msg = "";
int verified = 0;
int ret;
/* Process all hash subnodes of the component conf node */
for (noffset = fdt_first_subnode(fit, conf_noffset);
noffset >= 0;
noffset = fdt_next_subnode(fit, noffset)) {
const char *name = fit_get_name(fit, noffset, NULL);
if (!strncmp(name, FIT_SIG_NODENAME,
strlen(FIT_SIG_NODENAME))) {
ret = fit_config_check_sig(fit, noffset, sig_offset,
&err_msg);
if (ret) {
puts("- ");
} else {
puts("+ ");
verified = 1;
break;
}
}
}
if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
err_msg = "Corrupted or truncated tree";
goto error;
}
return verified ? 0 : -EPERM;
error:
printf(" error!\n%s for '%s' hash node in '%s' config node\n",
err_msg, fit_get_name(fit, noffset, NULL),
fit_get_name(fit, conf_noffset, NULL));
return -1;
}
int fit_config_verify_required_sigs(const void *fit, int conf_noffset,
const void *sig_blob)
{
int noffset;
int sig_node;
/* Work out what we need to verify */
sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
if (sig_node < 0) {
debug("%s: No signature node found: %s\n", __func__,
fdt_strerror(sig_node));
return 0;
}
for (noffset = fdt_first_subnode(sig_blob, sig_node);
noffset >= 0;
noffset = fdt_next_subnode(sig_blob, noffset)) {
const char *required;
int ret;
required = fdt_getprop(sig_blob, noffset, "required", NULL);
if (!required || strcmp(required, "conf"))
continue;
ret = fit_config_verify_sig(fit, conf_noffset, sig_blob,
noffset);
if (ret) {
printf("Failed to verify required signature '%s'\n",
fit_get_name(sig_blob, noffset, NULL));
return ret;
}
}
return 0;
}
int fit_config_verify(const void *fit, int conf_noffset)
{
return !fit_config_verify_required_sigs(fit, conf_noffset,
gd_fdt_blob());
}