Add dev_sign_file utility for developers to sign their install scripts.

utility/dev_sign_file.c

+/* Copyright (c) 2010 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.
+ *
+ * Developer file-signing utility
+ */
+
+#include <errno.h>
+#include <getopt.h>
+#include <inttypes.h>  /* For PRIu64 */
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "cryptolib.h"
+#include "host_common.h"
+#include "kernel_blob.h"
+#include "vboot_common.h"
+
+
+/* Global opt */
+static int opt_debug = 0;
+
+/* Command line options */
+enum {
+  OPT_MODE_SIGN = 1000,
+  OPT_MODE_VERIFY,
+  OPT_KEYBLOCK,
+  OPT_SIGNPRIVATE,
+  OPT_VBLOCK,
+};
+
+static struct option long_opts[] = {
+  {"sign", 1, 0,                      OPT_MODE_SIGN               },
+  {"verify", 1, 0,                    OPT_MODE_VERIFY             },
+  {"keyblock", 1, 0,                  OPT_KEYBLOCK                },
+  {"signprivate", 1, 0,               OPT_SIGNPRIVATE             },
+  {"vblock", 1, 0,                    OPT_VBLOCK                  },
+  {"debug", 0, &opt_debug, 1                                      },
+  {NULL, 0, 0, 0}
+};
+
+
+/* Print help and return error */
+static int PrintHelp(char *progname) {

[adlr, 2010/08/11 01:08:41]

const char*?

[Bill Richardson, 2010/08/11 18:14:47]

done

+  fprintf(stderr,
+          "This program is used to sign and verify developer-mode files\n");
+  fprintf(stderr,
+          "\n"
+          "Usage:  %s --sign <file> [PARAMETERS]\n"
+          "\n"
+          "  Required parameters:\n"
+          "    --keyblock <file>         Key block in .keyblock format\n"
+          "    --signprivate <file>"
+          "      Private key to sign file data, in .vbprivk format\n"
+          "    --vblock <file>           Output signature in .vblock format\n"
+          "\n",
+          progname);
+  fprintf(stderr,
+          "OR\n\n"
+          "Usage:  %s --verify <file> [PARAMETERS]\n"
+          "\n"
+          "  Required parameters:\n"
+          "    --vblock <file>           Signature file in .vblock format\n"
+          "\n",
+          progname);
+  return 1;
+}
+
+static void Debug(const char *format, ...) {
+  if (!opt_debug)
+    return;
+
+  va_list ap;
+  va_start(ap, format);
+  fprintf(stderr, "DEBUG: ");
+  vfprintf(stderr, format, ap);
+  va_end(ap);
+}
+
+
+/* Sign a file. We'll reuse the same structs used to sign kernels, to avoid
+   having to declare yet another one for just this purpose. */
+static int Sign(const char* filename, const char* keyblock_file,

[adlr, 2010/08/11 01:08:41]

i think our style says all args on one line or one arg per line

[Bill Richardson, 2010/08/11 18:14:47]

Actually, no. It should just look nice.

+                const char* signprivate_file, const char* outfile) {
+  uint8_t *file_data;

[adlr, 2010/08/11 01:08:41]

put * w/ the type, not the variable

[Bill Richardson, 2010/08/11 18:14:47]

Done

+  uint64_t file_size;
+  VbKeyBlockHeader* key_block;
+  uint64_t key_block_size;
+  VbPrivateKey* signing_key;
+  VbSignature* body_sig;
+  VbKernelPreambleHeader* preamble;
+  FILE* f;

[adlr, 2010/08/11 01:08:41]

avoid 1-letter variables except for iterators (again, our style guide)

+  uint64_t i;
+
+  /* Read the file that we're going to sign. */
+  file_data = ReadFile(filename, &file_size);
+  if (!file_data) {
+    error("Error reading file to sign.\n");
+    return 1;
+  }
+
+  /* Get the key block and read the private key corresponding to it. */
+  key_block = (VbKeyBlockHeader*)ReadFile(keyblock_file, &key_block_size);
+  if (!key_block) {
+    error("Error reading key block.\n");
+    return 1;
+  }
+  signing_key = PrivateKeyRead(signprivate_file);
+  if (!signing_key) {
+    error("Error reading signing key.\n");
+    return 1;
+  }
+
+  /* Sign the file data */
+  body_sig = CalculateSignature(file_data, file_size, signing_key);
+  if (!body_sig) {
+    error("Error calculating body signature\n");
+    return 1;
+  }
+
+  /* Create preamble */
+  preamble = CreateKernelPreamble(0UL, 0UL, 0UL, 0UL,

[adlr, 2010/08/11 01:08:41]

will you always compile this on 32 or 64-bit machines? if it could be either,
0UL could be 32 bits or 64 bits wide. You might consider something like
(uint64_t)0 instead if you need it to always be 64 bits wide. I don't have the
function header for CreateKernelPreamble, so this may be a bad idea if it takes
unsigned longs.

[Bill Richardson, 2010/08/11 18:14:47]

Ah. My bad. Thanks.

+                                  body_sig, 0UL, signing_key);
+  if (!preamble) {
+    error("Error creating preamble.\n");
+    return 1;
+  }
+
+  /* Write the output file */
+  Debug("writing %s...\n", outfile);
+  f = fopen(outfile, "wb");
+  if (!f) {
+    error("Can't open output file %s\n", outfile);
+    return 1;
+  }
+  Debug("0x%" PRIx64 " bytes of key_block\n", key_block_size);
+  Debug("0x%" PRIx64 " bytes of preamble\n", preamble->preamble_size);
+  i = ((1 != fwrite(key_block, key_block_size, 1, f)) ||
+       (1 != fwrite(preamble, preamble->preamble_size, 1, f)));
+  if (i) {
+    error("Can't write output file %s\n", outfile);
+    fclose(f);
+    unlink(outfile);
+    return 1;
+  }
+  fclose(f);
+
+  /* Done */
+  Free(preamble);
+  Free(body_sig);
+  Free(signing_key);
+  Free(key_block);
+  Free(file_data);
+
+  /* Success */
+  return 0;
+}
+
+static int Verify(const char* filename, const char* vblock_file) {
+  uint8_t *file_data;

[adlr, 2010/08/11 01:08:41]

* by type

[Bill Richardson, 2010/08/11 18:14:47]

Done.

+  uint64_t file_size;
+  uint8_t *buf;
+  uint64_t buf_size;
+  VbKeyBlockHeader* key_block;
+  VbKernelPreambleHeader* preamble;
+  VbPublicKey* data_key;
+  RSAPublicKey* rsa;
+  uint64_t now = 0;

[adlr, 2010/08/11 01:08:41]

i'm not sure what 'now' means. usually it's a timestamp, but it doesn't seem to
be one here

[Bill Richardson, 2010/08/11 18:14:47]

Clarified.

+
+  /* Read the file that we're going to verify. */
+  file_data = ReadFile(filename, &file_size);
+  if (!file_data) {
+    error("Error reading file to sign.\n");
+    return 1;
+  }
+
+  /* Read the vblock that we're going to use on it */
+  buf = ReadFile(vblock_file, &buf_size);
+  if (!buf) {
+    error("Error reading vblock_file.\n");
+    return 1;
+  }
+
+  /* Find the key block */
+  key_block = (VbKeyBlockHeader*)buf;
+  Debug("Keyblock is 0x%" PRIx64 " bytes\n", key_block->key_block_size);
+  now += key_block->key_block_size;
+  if (now > buf_size) {
+    error("key_block_size advances past the end of the buffer\n");
+    return 1;
+  }
+
+  /* Find the preamble */
+  preamble = (VbKernelPreambleHeader*)(buf + now);
+  Debug("Preamble is 0x%" PRIx64 " bytes\n", preamble->preamble_size);
+  now += preamble->preamble_size;
+  if (now > buf_size ) {
+    error("preamble_size advances past the end of the buffer\n");
+    return 1;
+  }
+
+  Debug("Now is at 0x%" PRIx64 " bytes\n", now);
+
+  /* Check the keyblock */
+  if (0 != KeyBlockVerify(key_block, file_size, NULL)) {
+    error("Error verifying key block.\n");
+    return 1;
+  }
+
+  printf("Key block:\n");
+  data_key = &key_block->data_key;
+//HEY   printf("  Signature:           %s\n", sign_key ? "valid" : "ignored");

[adlr, 2010/08/11 01:08:41]

delete this line?

[Bill Richardson, 2010/08/11 18:14:47]

Yes, thanks.

+  printf("  Size:                0x%" PRIx64 "\n", key_block->key_block_size);
+  printf("  Data key algorithm:  %" PRIu64 " %s\n", data_key->algorithm,
+         (data_key->algorithm < kNumAlgorithms ?
+          algo_strings[data_key->algorithm] : "(invalid)"));
+  printf("  Data key version:    %" PRIu64 "\n", data_key->key_version);
+  printf("  Flags:               %" PRIu64 "\n", key_block->key_block_flags);
+
+
+  /* Verify preamble */
+  rsa = PublicKeyToRSA(&key_block->data_key);
+  if (!rsa) {
+    error("Error parsing data key.\n");
+    return 1;
+  }
+  if (0 != VerifyKernelPreamble(
+        preamble, file_size, rsa)) {

[adlr, 2010/08/11 01:08:41]

seems like you can easily fit this on one line

[Bill Richardson, 2010/08/11 18:14:47]

done

+    error("Error verifying preamble.\n");
+    return 1;
+  }
+
+  printf("Preamble:\n");
+  printf("  Size:                0x%" PRIx64 "\n", preamble->preamble_size);
+  printf("  Header version:      %" PRIu32 ".%" PRIu32"\n",
+         preamble->header_version_major, preamble->header_version_minor);
+  printf("  Kernel version:      %" PRIu64 "\n", preamble->kernel_version);
+  printf("  Body load address:   0x%" PRIx64 "\n", preamble->body_load_address);
+  printf("  Body size:           0x%" PRIx64 "\n",
+         preamble->body_signature.data_size);
+  printf("  Bootloader address:  0x%" PRIx64 "\n",
+         preamble->bootloader_address);
+  printf("  Bootloader size:     0x%" PRIx64 "\n", preamble->bootloader_size);
+
+  /* Verify body */
+  if (0 != VerifyData(file_data, file_size, &preamble->body_signature,

[adlr, 2010/08/11 01:08:41]

all args on 1 line or 1 arg per line

[Bill Richardson, 2010/08/11 18:14:47]

done.

+                      rsa)) {
+    error("Error verifying kernel body.\n");
+    return 1;
+  }
+  printf("Body verification succeeded.\n");
+
+  // HEY

[adlr, 2010/08/11 01:08:41]

delete?

[Bill Richardson, 2010/08/11 18:14:47]

Yes, thanks.

+  return 0;
+}
+
+
+int main(int argc, char* argv[]) {
+  char* filename = NULL;
+  char* keyblock_file = NULL;
+  char* signprivate_file = NULL;
+  char* vblock_file = NULL;
+  int mode = 0;
+  int parse_error = 0;
+  int i;

[adlr, 2010/08/11 01:08:41]

rename "option_index"?

[Bill Richardson, 2010/08/11 18:14:47]

Done.

+
+  char *progname = strrchr(argv[0], '/');
+  if (progname)
+    progname++;
+  else
+    progname = argv[0];
+
+  while (((i = getopt_long(argc, argv, ":", long_opts, NULL)) != -1) &&
+         !parse_error) {
+    switch (i) {
+      default:
+      case '?':
+        /* Unhandled option */
+        parse_error = 1;
+        break;
+
+      case 0:
+        /* silently handled option */
+        break;
+
+      case OPT_MODE_SIGN:
+      case OPT_MODE_VERIFY:
+        if (mode && (mode != i)) {
+          fprintf(stderr, "Only a single mode can be specified\n");
+          parse_error = 1;
+          break;
+        }
+        mode = i;
+        filename = optarg;
+        break;
+
+      case OPT_KEYBLOCK:
+        keyblock_file = optarg;
+        break;
+
+      case OPT_SIGNPRIVATE:
+        signprivate_file = optarg;
+        break;
+
+      case OPT_VBLOCK:
+        vblock_file = optarg;
+        break;
+    }
+  }
+
+  if (parse_error)
+    return PrintHelp(progname);
+
+  switch(mode) {
+    case OPT_MODE_SIGN:
+      if (!keyblock_file || !signprivate_file || !vblock_file) {
+        fprintf(stderr, "Some required options are missing\n");
+        return PrintHelp(progname);
+      }
+      return Sign(filename, keyblock_file, signprivate_file, vblock_file);
+
+    case OPT_MODE_VERIFY:
+      if (!vblock_file) {
+        fprintf(stderr, "Some required options are missing\n");
+        return PrintHelp(progname);
+      }
+      return Verify(filename, vblock_file);
+
+    default:
+      fprintf(stderr,
+              "You must specify either --sign or --verify\n");
+      return PrintHelp(progname);
+  }
+
+  return 1;

[adlr, 2010/08/11 01:08:41]

// unreached?

[Bill Richardson, 2010/08/11 18:14:47]

Yes, but I don't like relying on the compiler to detect that I've handled all
the possible returns. I'll put a comment here.

+}