cbfstool: Add support for hashes as file metadata
They allow optimizing a verification of a whole CBFS image by only
dealing with the headers (assuming you choose to trust the hash
algorithm(s)).
The format allows for multiple hashes for a single file, and cbfstool
can handle them, but right now it can't generate such headers.
Loosely based on Sol's work in http://review.coreboot.org/#/c/10147/,
but using the compatible file attribute format. vboot is now a hard
dependency of the build process, but we import it into the tree for
quite a while now.
Change-Id: I9f14f30537d676ce209ad612e7327c6f4810b313
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/11767
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/util/cbfstool/Makefile.inc b/util/cbfstool/Makefile.inc
index a1dbfc3..4994757 100644
--- a/util/cbfstool/Makefile.inc
+++ b/util/cbfstool/Makefile.inc
@@ -15,6 +15,11 @@
cbfsobj += LzFind.o
cbfsobj += LzmaDec.o
cbfsobj += LzmaEnc.o
+# CRYPTOLIB
+cbfsobj += 2sha_utility.o
+cbfsobj += 2sha1.o
+cbfsobj += 2sha256.o
+cbfsobj += 2sha512.o
# FMAP
cbfsobj += fmap.o
cbfsobj += kv_pair.o
@@ -51,6 +56,9 @@
TOOLCPPFLAGS += -I$(top)/util/cbfstool
TOOLCPPFLAGS += -I$(objutil)/cbfstool
TOOLCPPFLAGS += -I$(top)/src/commonlib/include
+TOOLCPPFLAGS += -DNEED_VB2_SHA_LIBRARY
+TOOLCPPFLAGS += -I$(top)/3rdparty/vboot/firmware/include
+TOOLCPPFLAGS += -I$(top)/3rdparty/vboot/firmware/2lib/include
TOOLLDFLAGS ?=
ifeq ($(shell uname -s | cut -c-7 2>/dev/null), MINGW32)
@@ -77,6 +85,10 @@
printf " HOSTCC $(subst $(objutil)/,,$(@))\n"
$(HOSTCC) $(TOOLCPPFLAGS) $(TOOLCFLAGS) $(HOSTCFLAGS) -c -o $@ $<
+$(objutil)/cbfstool/%.o: $(top)/3rdparty/vboot/firmware/2lib/%.c
+ printf " HOSTCC $(subst $(objutil)/,,$(@))\n"
+ $(HOSTCC) $(TOOLCPPFLAGS) $(TOOLCFLAGS) $(HOSTCFLAGS) -c -o $@ $<
+
$(objutil)/cbfstool/cbfstool: $(addprefix $(objutil)/cbfstool/,$(cbfsobj))
printf " HOSTCC $(subst $(objutil)/,,$(@)) (link)\n"
$(HOSTCC) $(TOOLLDFLAGS) -o $@ $(addprefix $(objutil)/cbfstool/,$(cbfsobj))
@@ -97,6 +109,9 @@
$(objutil)/cbfstool/fmd_scanner.o: TOOLCFLAGS += -Wno-unused-function
# Tolerate lzma sdk warnings
$(objutil)/cbfstool/LzmaEnc.o: TOOLCFLAGS += -Wno-sign-compare -Wno-cast-qual
+# Tolerate vboot warnings
+$(objutil)/cbfstool/2sha_utility.o: TOOLCFLAGS += -Wno-sign-compare
+$(objutil)/cbfstool/2sha1.o: TOOLCFLAGS += -Wno-cast-qual
$(objutil)/cbfstool/fmd.o: $(objutil)/cbfstool/fmd_parser.h
$(objutil)/cbfstool/fmd.o: $(objutil)/cbfstool/fmd_scanner.h
diff --git a/util/cbfstool/cbfs.h b/util/cbfstool/cbfs.h
index 579afa6..8621805 100644
--- a/util/cbfstool/cbfs.h
+++ b/util/cbfstool/cbfs.h
@@ -19,8 +19,11 @@
#ifndef __CBFS_H
#define __CBFS_H
+#include "common.h"
#include <stdint.h>
+#include <vb2_api.h>
+
/* cbfstool will fail when trying to build a cbfs_file header that's larger
* than MAX_CBFS_FILE_HEADER_BUFFER. 1K should give plenty of room. */
#define MAX_CBFS_FILE_HEADER_BUFFER 1024
@@ -107,6 +110,7 @@
#define CBFS_FILE_ATTR_TAG_UNUSED 0
#define CBFS_FILE_ATTR_TAG_UNUSED2 0xffffffff
#define CBFS_FILE_ATTR_TAG_COMPRESSION 0x42435a4c
+#define CBFS_FILE_ATTR_TAG_HASH 0x68736148
struct cbfs_file_attr_compression {
uint32_t tag;
@@ -116,6 +120,14 @@
uint32_t decompressed_size;
} __PACKED;
+struct cbfs_file_attr_hash {
+ uint32_t tag;
+ uint32_t len;
+ uint32_t hash_type;
+ /* hash_data is len - sizeof(struct) bytes */
+ uint8_t hash_data[];
+} __PACKED;
+
struct cbfs_stage {
uint32_t compression;
uint64_t entry;
@@ -203,6 +215,23 @@
{CBFS_COMPONENT_NULL, "null"}
};
+static const struct typedesc_t types_cbfs_hash[] unused = {
+ {VB2_HASH_INVALID, "none"},
+ {VB2_HASH_SHA1, "sha1"},
+ {VB2_HASH_SHA256, "sha256"},
+ {VB2_HASH_SHA512, "sha512"},
+ {0, NULL}
+};
+
+static size_t widths_cbfs_hash[] unused = {
+ [VB2_HASH_INVALID] = 0,
+ [VB2_HASH_SHA1] = 20,
+ [VB2_HASH_SHA256] = 32,
+ [VB2_HASH_SHA512] = 64,
+};
+
+#define CBFS_NUM_SUPPORTED_HASHES ARRAY_SIZE(widths_cbfs_hash)
+
#define CBFS_SUBHEADER(_p) ( (void *) ((((uint8_t *) (_p)) + ntohl((_p)->offset))) )
/* cbfs_image.c */
diff --git a/util/cbfstool/cbfs_image.c b/util/cbfstool/cbfs_image.c
index 24ab0c4..895927d 100644
--- a/util/cbfstool/cbfs_image.c
+++ b/util/cbfstool/cbfs_image.c
@@ -85,6 +85,16 @@
return lookup_type_by_name(types_cbfs_compression, name);
}
+static const char *get_hash_attr_name(uint16_t hash_type)
+{
+ return lookup_name_by_type(types_cbfs_hash, hash_type, "(invalid)");
+}
+
+int cbfs_parse_hash_algo(const char *name)
+{
+ return lookup_type_by_name(types_cbfs_hash, name);
+}
+
/* CBFS image */
size_t cbfs_calculate_file_header_size(const char *name)
@@ -173,6 +183,24 @@
return compression;
}
+static struct cbfs_file_attr_hash *cbfs_file_get_next_hash(
+ struct cbfs_file *entry, struct cbfs_file_attr_hash *cur)
+{
+ struct cbfs_file_attribute *attr = (struct cbfs_file_attribute *)cur;
+ if (attr == NULL) {
+ attr = cbfs_file_first_attr(entry);
+ if (attr == NULL)
+ return NULL;
+ if (ntohl(attr->tag) == CBFS_FILE_ATTR_TAG_HASH)
+ return (struct cbfs_file_attr_hash *)attr;
+ }
+ while ((attr = cbfs_file_next_attr(entry, attr)) != NULL) {
+ if (ntohl(attr->tag) == CBFS_FILE_ATTR_TAG_HASH)
+ return (struct cbfs_file_attr_hash *)attr;
+ };
+ return NULL;
+}
+
void cbfs_get_header(struct cbfs_header *header, void *src)
{
struct buffer outheader;
@@ -813,6 +841,31 @@
);
}
+ struct cbfs_file_attr_hash *hash = NULL;
+ while ((hash = cbfs_file_get_next_hash(entry, hash)) != NULL) {
+ unsigned int hash_type = ntohl(hash->hash_type);
+ if (hash_type > CBFS_NUM_SUPPORTED_HASHES) {
+ fprintf(fp, "invalid hash type %d\n", hash_type);
+ break;
+ }
+ size_t hash_len = widths_cbfs_hash[hash_type];
+ char *hash_str = bintohex(hash->hash_data, hash_len);
+ uint8_t local_hash[hash_len];
+ if (vb2_digest_buffer(CBFS_SUBHEADER(entry),
+ ntohl(entry->len), hash_type, local_hash,
+ hash_len) != VB2_SUCCESS) {
+ fprintf(fp, "failed to hash '%s'\n", name);
+ break;
+ }
+ int valid = memcmp(local_hash, hash->hash_data, hash_len) == 0;
+ const char *valid_str = valid ? "valid" : "invalid";
+
+ fprintf(fp, " hash %s:%s %s\n",
+ get_hash_attr_name(hash_type),
+ hash_str, valid_str);
+ free(hash_str);
+ }
+
if (!verbose)
return 0;
@@ -1129,6 +1182,32 @@
return attr;
}
+int cbfs_add_file_hash(struct cbfs_file *header, struct buffer *buffer,
+ enum vb2_hash_algorithm hash_type)
+{
+ if (hash_type >= CBFS_NUM_SUPPORTED_HASHES)
+ return -1;
+
+ unsigned hash_size = widths_cbfs_hash[hash_type];
+ if (hash_size == 0)
+ return -1;
+
+ struct cbfs_file_attr_hash *attrs =
+ (struct cbfs_file_attr_hash *)cbfs_add_file_attr(header,
+ CBFS_FILE_ATTR_TAG_HASH,
+ sizeof(struct cbfs_file_attr_hash) + hash_size);
+
+ if (attrs == NULL)
+ return -1;
+
+ attrs->hash_type = htonl(hash_type);
+ if (vb2_digest_buffer(buffer_get(buffer), buffer_size(buffer),
+ hash_type, attrs->hash_data, hash_size) != VB2_SUCCESS)
+ return -1;
+
+ return 0;
+}
+
/* Finds a place to hold whole data in same memory page. */
static int is_in_same_page(uint32_t start, uint32_t size, uint32_t page)
{
diff --git a/util/cbfstool/cbfs_image.h b/util/cbfstool/cbfs_image.h
index baceb51..f602976 100644
--- a/util/cbfstool/cbfs_image.h
+++ b/util/cbfstool/cbfs_image.h
@@ -36,6 +36,10 @@
* enum comp_algo if it's supported, or a number < 0 otherwise. */
int cbfs_parse_comp_algo(const char *name);
+/* Given the string name of a hash algorithm, return the corresponding
+ * id if it's supported, or a number < 0 otherwise. */
+int cbfs_parse_hash_algo(const char *name);
+
/* Given a pointer, serialize the header from host-native byte format
* to cbfs format, i.e. big-endian. */
void cbfs_put_header(void *dest, const struct cbfs_header *header);
@@ -184,4 +188,10 @@
struct cbfs_file_attribute *cbfs_add_file_attr(struct cbfs_file *header,
uint32_t tag,
uint32_t size);
+
+/* Adds an extended attribute to header, containing a hash of buffer's data of
+ * the type specified by hash_type.
+ * Returns 0 on success, -1 on error. */
+int cbfs_add_file_hash(struct cbfs_file *header, struct buffer *buffer,
+ enum vb2_hash_algorithm hash_type);
#endif
diff --git a/util/cbfstool/cbfstool.c b/util/cbfstool/cbfstool.c
index 35747d3..2876702 100644
--- a/util/cbfstool/cbfstool.c
+++ b/util/cbfstool/cbfstool.c
@@ -76,6 +76,7 @@
bool stage_xip;
int fit_empty_entries;
enum comp_algo compression;
+ enum vb2_hash_algorithm hash;
/* for linux payloads */
char *initrd;
char *cmdline;
@@ -83,6 +84,7 @@
/* All variables not listed are initialized as zero. */
.arch = CBFS_ARCHITECTURE_UNKNOWN,
.compression = CBFS_COMPRESS_NONE,
+ .hash = VB2_HASH_INVALID,
.headeroffset = ~0,
.region_name = SECTION_NAME_PRIMARY_CBFS,
};
@@ -327,6 +329,14 @@
return 1;
}
+ if (param.hash != VB2_HASH_INVALID)
+ if (cbfs_add_file_hash(header, &buffer, param.hash) == -1) {
+ ERROR("couldn't add hash for '%s'\n", name);
+ free(header);
+ buffer_delete(&buffer);
+ return 1;
+ }
+
if (IS_TOP_ALIGNED_ADDRESS(offset))
offset = convert_to_from_top_aligned(param.image_region,
-offset);
@@ -882,11 +892,11 @@
}
static const struct command commands[] = {
- {"add", "H:r:f:n:t:c:b:a:vh?", cbfs_add, true, true},
- {"add-flat-binary", "H:r:f:n:l:e:c:b:vh?", cbfs_add_flat_binary, true,
+ {"add", "H:r:f:n:t:c:b:a:vA:h?", cbfs_add, true, true},
+ {"add-flat-binary", "H:r:f:n:l:e:c:b:vA:h?", cbfs_add_flat_binary, true,
true},
- {"add-payload", "H:r:f:n:t:c:b:C:I:vh?", cbfs_add_payload, true, true},
- {"add-stage", "a:H:r:f:n:t:c:b:P:S:yvh?", cbfs_add_stage, true, true},
+ {"add-payload", "H:r:f:n:t:c:b:C:I:vA:h?", cbfs_add_payload, true, true},
+ {"add-stage", "a:H:r:f:n:t:c:b:P:S:yvA:h?", cbfs_add_stage, true, true},
{"add-int", "H:r:i:n:b:vh?", cbfs_add_integer, true, true},
{"add-master-header", "H:r:vh?", cbfs_add_master_header, true, true},
{"copy", "H:D:s:h?", cbfs_copy, true, true},
@@ -914,6 +924,7 @@
{"fill-upward", no_argument, 0, 'u' },
{"flashmap", required_argument, 0, 'M' },
{"fmap-regions", required_argument, 0, 'r' },
+ {"hash-algorithm",required_argument, 0, 'A' },
{"header-offset", required_argument, 0, 'H' },
{"help", no_argument, 0, 'h' },
{"ignore-sec", required_argument, 0, 'S' },
@@ -997,18 +1008,18 @@
" -v Provide verbose output\n"
" -h Display this help message\n\n"
"COMMANDs:\n"
- " add [-r image,regions] -f FILE -n NAME -t TYPE \\\n"
+ " add [-r image,regions] -f FILE -n NAME -t TYPE [-A hash] \\\n"
" [-c compression] [-b base-address | -a alignment] "
"Add a component\n"
- " add-payload [-r image,regions] -f FILE -n NAME \\\n"
+ " add-payload [-r image,regions] -f FILE -n NAME [-A hash] \\\n"
" [-c compression] [-b base-address] "
"Add a payload to the ROM\n"
" (linux specific: [-C cmdline] [-I initrd])\n"
- " add-stage [-r image,regions] -f FILE -n NAME \\\n"
+ " add-stage [-r image,regions] -f FILE -n NAME [-A hash] \\\n"
" [-c compression] [-b base] [-S section-to-ignore] "
" [-a alignment] [-y|--xip] [-P page-size]"
"Add a stage to the ROM\n"
- " add-flat-binary [-r image,regions] -f FILE -n NAME \\\n"
+ " add-flat-binary [-r image,regions] -f FILE -n NAME [-A hash] \\\n"
" -l load-address -e entry-point [-c compression] \\\n"
" [-b base] "
"Add a 32bit flat mode binary\n"
@@ -1132,6 +1143,17 @@
optarg);
break;
}
+ case 'A': {
+ int algo = cbfs_parse_hash_algo(optarg);
+ if (algo >= 0)
+ param.hash = algo;
+ else {
+ ERROR("Unknown hash algorithm '%s'.\n",
+ optarg);
+ return 1;
+ }
+ break;
+ }
case 'M':
param.fmap = optarg;
break;