diff options
Diffstat (limited to 'tools/fit_image.c')
| -rw-r--r-- | tools/fit_image.c | 101 |
1 files changed, 93 insertions, 8 deletions
diff --git a/tools/fit_image.c b/tools/fit_image.c index 1dbc14c63e4..5831b07c090 100644 --- a/tools/fit_image.c +++ b/tools/fit_image.c @@ -40,10 +40,10 @@ static int fit_estimate_hash_sig_size(struct image_tool_params *params, const ch return -EIO; /* - * Walk the FIT image, looking for nodes named hash* and - * signature*. Since the interesting nodes are subnodes of an - * image or configuration node, we are only interested in - * those at depth exactly 3. + * Walk the FIT image, looking for nodes named hash*, + * signature*, and dm-verity. Since the interesting nodes are + * subnodes of an image or configuration node, we are only + * interested in those at depth exactly 3. * * The estimate for a hash node is based on a sha512 digest * being 64 bytes, with another 64 bytes added to account for @@ -55,6 +55,10 @@ static int fit_estimate_hash_sig_size(struct image_tool_params *params, const ch * account for fdt overhead and the various other properties * (hashed-nodes etc.) that will also be filled in. * + * For a dm-verity node the small metadata properties (digest, + * salt, two u32s and a temp-file path) are written into the + * FDT by fit_image_process_verity(). + * * One could try to be more precise in the estimates by * looking at the "algo" property and, in the case of * configuration signatures, the sign-images property. Also, @@ -76,6 +80,18 @@ static int fit_estimate_hash_sig_size(struct image_tool_params *params, const ch if (signing && !strncmp(name, FIT_SIG_NODENAME, strlen(FIT_SIG_NODENAME))) estimate += 1024; + + if (!strcmp(name, FIT_VERITY_NODENAME)) { + if (!params->external_data) { + fprintf(stderr, + "%s: dm-verity requires external data (-E)\n", + params->cmdname); + munmap(fdt, sbuf.st_size); + close(fd); + return -EINVAL; + } + estimate += 256; + } } munmap(fdt, sbuf.st_size); @@ -265,8 +281,14 @@ static void get_basename(char *str, int size, const char *fname) */ p = strrchr(fname, '/'); start = p ? p + 1 : fname; - p = strrchr(fname, '.'); - end = p ? p : fname + strlen(fname); + /* + * Search for the extension dot only within the basename. Searching + * the whole path would let a dot in the directory part (for example + * "./mydt" or "a.b/c") place 'end' before 'start' and produce a + * negative length, which the size check below does not catch. + */ + p = strrchr(start, '.'); + end = p ? p : start + strlen(start); len = end - start; if (len >= size) len = size - 1; @@ -471,6 +493,41 @@ static int fit_write_images(struct image_tool_params *params, char *fdt) } /** + * fit_copy_image_data() - copy image data, using cached verity expansion + * @fdt: FIT blob + * @node: image node offset + * @buf: destination buffer + * @buf_ptr: write offset within @buf + * @data: embedded image data (used when no dm-verity expansion exists) + * @lenp: in/out: on entry, length of @data; on exit, bytes written + * + * When fit_image_process_verity() has run, the expanded image data + * (original + hash tree) is cached in memory. Look it up by image name + * and copy from the cached buffer rather than the embedded ``data`` + * property; fall back to @data otherwise. + * + * Return: 0 on success + */ +static int fit_copy_image_data(void *fdt, int node, void *buf, + int buf_ptr, const void *data, int *lenp) +{ + const char *image_name = fdt_get_name(fdt, node, NULL); + const void *vdata; + size_t vsize; + + if (image_name && + !fit_verity_get_expanded(image_name, &vdata, &vsize)) { + memcpy(buf + buf_ptr, vdata, vsize); + *lenp = vsize; + return 0; + } + + memcpy(buf + buf_ptr, data, *lenp); + + return 0; +} + +/** * fit_write_configs() - Write out a list of configurations to the FIT * * If there are device tree files, we include a configuration for each, which @@ -653,6 +710,8 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname) int node; int align_size = 0; int len = 0; + int verity_extra = 0; + int orig_len; fd = mmap_fdt(params->cmdname, fname, 0, &fdt, &sbuf, false, false); if (fd < 0) @@ -687,10 +746,33 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname) } /* + * When dm-verity is active the external data for an image is + * larger than the embedded data property (original + hash tree). + * Walk images once more and consult the in-memory cache for the + * actual expanded size. + */ + fdt_for_each_subnode(node, fdt, images) { + const char *image_name; + const void *vdata; + size_t vsize; + + orig_len = 0; + if (fdt_subnode_offset(fdt, node, FIT_VERITY_NODENAME) < 0) + continue; + image_name = fdt_get_name(fdt, node, NULL); + if (!image_name || + fit_verity_get_expanded(image_name, &vdata, &vsize)) + continue; + fdt_getprop(fdt, node, FIT_DATA_PROP, &orig_len); + if ((int)vsize > orig_len) + verity_extra += (int)vsize - orig_len; + } + + /* * Allocate space to hold the image data we will extract, * extral space allocate for image alignment to prevent overflow. */ - buf = calloc(1, fit_size + align_size); + buf = calloc(1, fit_size + align_size + verity_extra); if (!buf) { ret = -ENOMEM; goto err_munmap; @@ -721,7 +803,10 @@ static int fit_extract_data(struct image_tool_params *params, const char *fname) data = fdt_getprop(fdt, node, FIT_DATA_PROP, &len); if (!data) continue; - memcpy(buf + buf_ptr, data, len); + + ret = fit_copy_image_data(fdt, node, buf, buf_ptr, data, &len); + if (ret) + goto err_munmap; debug("Extracting data size %x\n", len); ret = fdt_delprop(fdt, node, FIT_DATA_PROP); |