diff options
author | Daisuke Nojiri <dnojiri@chromium.org> | 2016-09-14 12:55:20 -0700 |
---|---|---|
committer | chrome-bot <chrome-bot@chromium.org> | 2016-10-01 00:01:13 -0700 |
commit | 8130e503414f16b9e4c5395b3acad69ad34b7baf (patch) | |
tree | 132c33a9ecf65cfdebbf1de3bccd12a485421a0c /utility | |
parent | 3b44f30597e6ff86ddd8fd9e77ea278b935b15ea (diff) | |
download | vboot-8130e503414f16b9e4c5395b3acad69ad34b7baf.tar.gz |
bdb: Add bdb_extend
bdb_extend prints out secrets derived from the given BDS based on
the given BDB.
BUG=chromium:649555
BRANCH=none
TEST=make runtests. Ran bdb_extend -s bds.bin -b bdb.bin (with/without -m)
Change-Id: I8d9f73468992dad4cb93a422c0eae0977be9a16f
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/385539
Diffstat (limited to 'utility')
-rw-r--r-- | utility/bdb_extend.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/utility/bdb_extend.c b/utility/bdb_extend.c new file mode 100644 index 00000000..c66f8bb2 --- /dev/null +++ b/utility/bdb_extend.c @@ -0,0 +1,189 @@ +/* Copyright 2016 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include "2sha.h" +#include "bdb.h" +#include "bdb_api.h" +#include "host.h" + +static f_extend extend = vb2_sha256_extend; + +static void help(void) +{ + fprintf(stderr, + "Usage: bdb_extend -b bdb_file -s bds_file " + "[-d digest_file] [-m]\n" + "\n" + "Extends BDS based on a given BDB. When '-m' is given, a " + "MVMAP2315's sha256_extend algorithm will be used. When " + "digest_file is specified, the validity of the BDB key is " + "checked and the secrets will be derived differently.\n"); +} + +#define PACK32(str, x) \ + { \ + *(x) = ((uint32_t) *((str) + 3) ) \ + | ((uint32_t) *((str) + 2) << 8) \ + | ((uint32_t) *((str) + 1) << 16) \ + | ((uint32_t) *((str) + 0) << 24); \ + } + +/** + * MVMAP2315's implementation of sha256 extend + * + * This performs incorrect but still cryptographically secure sha256 extension. + * This is provided for test purpose only. + * + * See vb2_sha256_extend for details on arguments. + */ +static void mvmap2315_sha256_extend(const uint8_t *from, const uint8_t *by, + uint8_t *to) +{ + struct vb2_sha256_context dc; + int i; + + vb2_sha256_init(&dc); + for (i = 0; i < 8; i++) { + PACK32(from, &dc.h[i]); + from += 4; + } + vb2_sha256_update(&dc, by, VB2_SHA256_BLOCK_SIZE); + vb2_sha256_finalize(&dc, to); +} + +static void dump_secret(const uint8_t *secret, const char *label) +{ + int i; + printf("%s = {", label); + for (i = 0; i < BDB_SECRET_SIZE; i++) { + if (i % 8 == 0) + printf("\n\t"); + else + printf(" "); + printf("0x%02x,", secret[i]); + } + printf("\n}\n"); +} + +static void dump_secrets(struct vba_context *ctx, const uint8_t *wsr) +{ + dump_secret(ctx->secrets->bdb, "bdb"); + dump_secret(ctx->secrets->boot_path, "boot_path"); + dump_secret(ctx->secrets->boot_verified, "boot_verified"); + dump_secret(ctx->secrets->nvm_wp, "nvm_wp"); + dump_secret(ctx->secrets->nvm_rw, "nvm_rw"); + dump_secret(wsr, "wsr"); +} + +static int derive_secrets(struct vba_context *ctx, + const uint8_t *bdb, uint8_t *wsr) +{ + struct bdb_secrets secrets; + + memset(&secrets, 0, sizeof(secrets)); + + ctx->secrets = &secrets; + if (vba_extend_secrets_ro(ctx, bdb, wsr, extend)) { + fprintf(stderr, "ERROR: Failed to derive secrets\n"); + return -1; + } + + fprintf(stderr, "LOG: Secrets are derived as follows\n"); + dump_secrets(ctx, wsr); + + return 0; +} + +int main(int argc, char *argv[]) +{ + struct vba_context ctx; + uint8_t *bdb, *bds; + uint8_t *key_digest = NULL; + uint32_t bdb_size, bds_size, digest_size; + const char *bdb_file = NULL; + const char *digest_file = NULL; + const char *bds_file = NULL; + int rv; + int opt; + + while ((opt = getopt(argc, argv, "b:d:hms:")) != -1) { + switch(opt) { + case 'b': + bdb_file = optarg; + break; + case 'd': + digest_file = optarg; + break; + case 'h': + help(); + return 0; + case 'm': + extend = mvmap2315_sha256_extend; + break; + case 's': + bds_file = optarg; + break; + default: + help(); + return -1; + } + } + + if (!bdb_file || !bds_file) { + fprintf(stderr, "ERROR: BDB and BDS aren't specified\n\n"); + help(); + return -1; + } + + /* Read BDB */ + bdb = read_file(bdb_file, &bdb_size); + if (!bdb) { + fprintf(stderr, "ERROR: Unable to read %s\n", bdb_file); + return -1; + } + + /* Read BDS */ + bds = read_file(bds_file, &bds_size); + if (!bds) { + fprintf(stderr, "ERROR: Unable to read %s\n", bds_file); + return -1; + } + if (bds_size != BDB_SECRET_SIZE) { + fprintf(stderr, "ERROR: Invalid BDS size: %d\n", bds_size); + return -1; + } + + /* Read key digest if provided */ + if (digest_file) { + key_digest = read_file(digest_file, &digest_size); + if (!key_digest) { + fprintf(stderr, + "ERROR: Unable to read %s\n", digest_file); + return -1; + } + } + + /* Verify BDB and set a flag based on the result */ + memset(&ctx, 0, sizeof(ctx)); + rv = bdb_verify(bdb, bdb_size, key_digest); + if (rv) { + if (rv != BDB_GOOD_OTHER_THAN_KEY) { + fprintf(stderr, "ERROR: BDB is invalid: %d\n", rv); + return -1; + } + fprintf(stderr, + "WARNING: BDB is valid but key digest doesn't match\n"); + } else { + ctx.flags |= VBA_CONTEXT_FLAG_BDB_KEY_EFUSED; + fprintf(stderr, "BDB is successfully verified by eFused key\n"); + } + + /* Derive secrets and dump the values */ + return derive_secrets(&ctx, bdb, bds); +} |