Add support for signing images using a new signature node. The process is handled by fdt_add_verification_data() which now takes parameters to provide the keys and related information.
Signed-off-by: Simon Glass sjg@chromium.org --- doc/uImage.FIT/sign-images.its | 42 +++++++++ include/image.h | 22 ++++- tools/fit_image.c | 2 +- tools/image-host.c | 181 +++++++++++++++++++++++++++++++++++++-- 4 files changed, 232 insertions(+), 15 deletions(-) create mode 100644 doc/uImage.FIT/sign-images.its
diff --git a/doc/uImage.FIT/sign-images.its b/doc/uImage.FIT/sign-images.its new file mode 100644 index 0000000..f69326a --- /dev/null +++ b/doc/uImage.FIT/sign-images.its @@ -0,0 +1,42 @@ +/dts-v1/; + +/ { + description = "Chrome OS kernel image with one or more FDT blobs"; + #address-cells = <1>; + + images { + kernel@1 { + data = /incbin/("test-kernel.bin"); + type = "kernel_noload"; + arch = "sandbox"; + os = "linux"; + compression = "none"; + load = <0x4>; + entry = <0x8>; + kernel-version = <1>; + signature@1 { + algo = "sha1,rsa2048"; + key-name-hint = "dev"; + }; + }; + fdt@1 { + description = "snow"; + data = /incbin/("sandbox-kernel.dtb"); + type = "flat_dt"; + arch = "sandbox"; + compression = "none"; + fdt-version = <1>; + signature@1 { + algo = "sha1,rsa2048"; + key-name-hint = "dev"; + }; + }; + }; + configurations { + default = "conf@1"; + conf@1 { + kernel = "kernel@1"; + fdt = "fdt@1"; + }; + }; +}; diff --git a/include/image.h b/include/image.h index 8c648dc..a1072c0 100644 --- a/include/image.h +++ b/include/image.h @@ -611,12 +611,26 @@ int fit_image_hash_get_ignore(const void *fit, int noffset, int *ignore); int fit_set_timestamp(void *fit, int noffset, time_t timestamp);
/** - * fit_add_verification_data() - Calculate and add hashes to FIT + * fit_add_verification_data() - add verification data to FIT image nodes * - * @fit: Fit image to process - * @return 0 if ok, <0 for error + * @keydir: Directory containing keys + * @kwydest: FDT blob to write public key information to + * @fit: Pointer to the FIT format image header + * @comment: Comment to add to signature nodes + * @require_keys: Mark all keys as 'required' + * + * Adds hash values for all component images in the FIT blob. + * Hashes are calculated for all component images which have hash subnodes + * with algorithm property set to one of the supported hash algorithms. + * + * Also add signatures if signature nodes are present. + * + * returns + * 0, on success + * libfdt error code, on failure */ -int fit_add_verification_data(void *fit); +int fit_add_verification_data(const char *keydir, void *keydest, void *fit, + const char *comment, int require_keys);
int fit_image_verify(const void *fit, int noffset); int fit_all_image_verify(const void *fit); diff --git a/tools/fit_image.c b/tools/fit_image.c index 8f51159..e0675d7 100644 --- a/tools/fit_image.c +++ b/tools/fit_image.c @@ -125,7 +125,7 @@ static int fit_handle_file (struct mkimage_params *params) }
/* set hashes for images in the blob */ - if (fit_add_verification_data(ptr)) { + if (fit_add_verification_data(NULL, NULL, ptr, NULL, 0)) { fprintf (stderr, "%s Can't add hashes to FIT blob", params->cmdname); unlink (tmpfile); diff --git a/tools/image-host.c b/tools/image-host.c index 4c589af..4196190 100644 --- a/tools/image-host.c +++ b/tools/image-host.c @@ -26,12 +26,8 @@ */
#include "mkimage.h" -#include <bootstage.h> #include <image.h> -#include <sha1.h> -#include <time.h> -#include <u-boot/crc.h> -#include <u-boot/md5.h> +#include <version.h>
/** * fit_set_hash_value - set hash value in requested has node @@ -113,9 +109,161 @@ static int fit_image_process_hash(void *fit, const char *image_name, }
/** - * fit_image_add_verification_data() - calculate/set hash data for image node + * fit_image_write_sig() - write the signature to a FIT * - * This adds hash values for a component image node. + * This writes the signature and signer data to the FIT. + * + * @fit: pointer to the FIT format image header + * @noffset: hash node offset + * @value: signature value to be set + * @value_len: signature value length + * @comment: Text comment to write (NULL for none) + * + * returns + * 0, on success + * -1, on failure + */ +static int fit_image_write_sig(void *fit, int noffset, uint8_t *value, + int value_len, const char *comment, const char *region_prop, + int region_proplen) +{ + int string_size; + int ret; + + /* + * Get the current string size, before we update the FIT and add + * more + */ + string_size = fdt_size_dt_strings(fit); + + ret = fdt_setprop(fit, noffset, FIT_VALUE_PROP, value, value_len); + ret |= fdt_setprop_string(fit, noffset, "signer-name", "mkimage"); + ret |= fdt_setprop_string(fit, noffset, "signer-version", + PLAIN_VERSION); + if (comment) + ret |= fdt_setprop_string(fit, noffset, "comment", comment); + ret |= fit_set_timestamp(fit, noffset, time(NULL)); + if (region_prop) { + uint32_t strdata[2]; + + ret |= fdt_setprop(fit, noffset, "hashed-nodes", + region_prop, region_proplen); + strdata[0] = 0; + strdata[1] = cpu_to_fdt32(string_size); + ret |= fdt_setprop(fit, noffset, "hashed-strings", strdata, + sizeof(strdata)); + } + + return ret; +} + +static int fit_image_setup_sig(struct image_sign_info *info, + const char *keydir, void *fit, const char *image_name, + int noffset, const char *require_keys) +{ + const char *node_name; + char *algo_name; + + node_name = fit_get_name(fit, noffset, NULL); + if (fit_image_hash_get_algo(fit, noffset, &algo_name)) { + printf("Can't get algo property for " + "'%s' signature node in '%s' image node\n", + node_name, image_name); + return -1; + } + + memset(info, '\0', sizeof(*info)); + info->keydir = keydir; + info->keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL); + info->fit = fit; + info->node_offset = noffset; + info->algo = image_get_sig_algo(algo_name); + info->require_keys = require_keys; + if (!info->algo) { + printf("Unsupported signature algorithm (%s) for " + "'%s' signature node in '%s' image node\n", + algo_name, node_name, image_name); + return -1; + } + + return 0; +} + +/** + * fit_image_process_sig- Process a single subnode of the images/ node + * + * Check each subnode and process accordingly. For signature nodes we + * generate a signed hash of the supplised data and store it in the node. + * + * @keydir: Directory containing keys to use for signing + * @keydest: Destination FDT blob to write public keys into + * @fit: pointer to the FIT format image header + * @image_name: name of image being processes (used to display errors) + * @noffset: subnode offset + * @data: data to process + * @size: size of data in bytes + * @comment: Comment to add to signature nodes + * @require_keys: Mark all keys as 'required' + * @return 0 if ok, -1 on error + */ +static int fit_image_process_sig(const char *keydir, void *keydest, + void *fit, const char *image_name, + int noffset, const void *data, size_t size, + const char *comment, int require_keys) +{ + struct image_sign_info info; + struct image_region region; + const char *node_name; + uint8_t *value; + uint value_len; + int ret; + + if (fit_image_setup_sig(&info, keydir, fit, image_name, noffset, + require_keys ? "image" : NULL)) + return -1; + + node_name = fit_get_name(fit, noffset, NULL); + region.data = data; + region.size = size; + ret = info.algo->sign(&info, ®ion, 1, &value, &value_len); + if (ret) { + printf("Failed to sign '%s' signature node in '%s'" + " image node: %d\n", + node_name, image_name, ret); + + /* We allow keys to be missing */ + if (ret == -ENOENT) + return 0; + return -1; + } + + if (fit_image_write_sig(fit, noffset, value, value_len, comment, + NULL, 0)) { + printf("Can't write signature for " + "'%s' signature node in '%s' image node\n", + node_name, image_name); + return -1; + } + free(value); + + /* Get keyname again, as FDT has changed and invalidated our pointer */ + info.keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL); + + /* Write the public key into the supplied FDT file */ + if (keydest && info.algo->add_verify_data(&info, keydest)) { + printf("Failed to add verification data for " + "'%s' signature node in '%s' image node\n", + node_name, image_name); + return -1; + } + + return 0; +} + +/** + * fit_image_add_verification_data() - calculate/set verig. data for image node + * + * This adds hash and signature values for an component image node. * * All existing hash subnodes are checked, if algorithm property is set to * one of the supported hash algorithms, hash value is computed and @@ -138,11 +286,17 @@ static int fit_image_process_hash(void *fit, const char *image_name, * * For signature details, please see doc/uImage.FIT/signature.txt * + * @keydir Directory containing *.key and *.crt files (or NULL) + * @keydest FDT Blob to write public keys into (NULL if none) * @fit: Pointer to the FIT format image header * @image_noffset: Requested component image node + * @comment: Comment to add to signature nodes + * @require_keys: Mark all keys as 'required' * @return: 0 on success, <0 on failure */ -int fit_image_add_verification_data(void *fit, int image_noffset) +int fit_image_add_verification_data(const char *keydir, void *keydest, + void *fit, int image_noffset, const char *comment, + int require_keys) { const char *image_name; const void *data; @@ -176,6 +330,11 @@ int fit_image_add_verification_data(void *fit, int image_noffset) strlen(FIT_HASH_NODENAME))) { ret = fit_image_process_hash(fit, image_name, noffset, data, size); + } else if (keydir && !strncmp(node_name, FIT_SIG_NODENAME, + strlen(FIT_SIG_NODENAME))) { + ret = fit_image_process_sig(keydir, keydest, + fit, image_name, noffset, data, size, + comment, require_keys); } if (ret) return -1; @@ -184,7 +343,8 @@ int fit_image_add_verification_data(void *fit, int image_noffset) return 0; }
-int fit_add_verification_data(void *fit) +int fit_add_verification_data(const char *keydir, void *keydest, void *fit, + const char *comment, int require_keys) { int images_noffset; int noffset; @@ -209,7 +369,8 @@ int fit_add_verification_data(void *fit) * Direct child node of the images parent node, * i.e. component image node. */ - ret = fit_image_add_verification_data(fit, noffset); + ret = fit_image_add_verification_data(keydir, keydest, + fit, noffset, comment, require_keys); if (ret) return ret; }