lib: rsa: decouple rsa from FIT image verification
Introduce new configuration, CONFIG_RSA_VERIFY which will decouple building
RSA functions from FIT verification and allow for adding a RSA-based
signature verification for other file formats, in particular PE file
for UEFI secure boot.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/image-fit-sig.c b/common/image-fit-sig.c
new file mode 100644
index 0000000..f6caeb0
--- /dev/null
+++ b/common/image-fit-sig.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2013, Google Inc.
+ */
+
+#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 <u-boot/rsa.h>
+#include <u-boot/rsa-checksum.h>
+
+#define IMAGE_MAX_HASHED_NODES 100
+
+#ifdef USE_HOSTCC
+void *host_blob;
+
+void image_set_host_blob(void *blob)
+{
+ host_blob = blob;
+}
+
+void *image_get_host_blob(void)
+{
+ return host_blob;
+}
+#endif
+
+/**
+ * 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;
+ const char *padding_name;
+
+ if (fdt_totalsize(fit) > CONFIG_FIT_SIGNATURE_MAX_SIZE) {
+ *err_msgp = "Total size too large";
+ return 1;
+ }
+
+ if (fit_image_hash_get_algo(fit, noffset, &algo_name)) {
+ *err_msgp = "Can't get hash algo property";
+ return -1;
+ }
+
+ padding_name = fdt_getprop(fit, noffset, "padding", NULL);
+ if (!padding_name)
+ padding_name = RSA_DEFAULT_PADDING_NAME;
+
+ memset(info, '\0', sizeof(*info));
+ info->keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL);
+ info->fit = (void *)fit;
+ info->node_offset = noffset;
+ info->name = algo_name;
+ info->checksum = image_get_checksum_algo(algo_name);
+ info->crypto = image_get_crypto_algo(algo_name);
+ info->padding = image_get_padding_algo(padding_name);
+ info->fdt_blob = gd_fdt_blob();
+ info->required_keynode = required_keynode;
+ printf("%s:%s", algo_name, info->keyname);
+
+ if (!info->checksum || !info->crypto || !info->padding) {
+ *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.crypto->verify(&info, ®ion, 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 */
+ fdt_for_each_subnode(noffset, fit, image_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;
+ }
+
+ fdt_for_each_subnode(noffset, sig_blob, sig_node) {
+ 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;
+ }
+
+ if (prop && prop_len > 0 && prop[prop_len - 1] != '\0') {
+ *err_msgp = "hashed-nodes property must be null-terminated";
+ 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) {
+ /*
+ * The strings region offset must be a static 0x0.
+ * This is set in tool/image-host.c
+ */
+ fdt_regions[count].offset = fdt_off_dt_strings(fit);
+ 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.crypto->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 */
+ fdt_for_each_subnode(noffset, fit, conf_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;
+ }
+
+ fdt_for_each_subnode(noffset, sig_blob, sig_node) {
+ 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());
+}