1#!/bin/bash 2 3# Copyright 2015 The Chromium OS Authors. All rights reserved. 4# Use of this source code is governed by a BSD-style license that can be 5# found in the LICENSE file. 6 7# Script to generate a Brillo update for use by the update engine. 8# 9# usage: brillo_update_payload COMMAND [ARGS] 10# The following commands are supported: 11# generate generate an unsigned payload 12# hash generate a payload or metadata hash 13# sign generate a signed payload 14# properties generate a properties file from a payload 15# 16# Generate command arguments: 17# --payload generated unsigned payload output file 18# --source_image if defined, generate a delta payload from the specified 19# image to the target_image 20# --target_image the target image that should be sent to clients 21# --metadata_size_file if defined, generate a file containing the size of the payload 22# metadata in bytes to the specified file 23# 24# Hash command arguments: 25# --unsigned_payload the input unsigned payload to generate the hash from 26# --signature_size signature sizes in bytes in the following format: 27# "size1:size2[:...]" 28# --payload_hash_file if defined, generate a payload hash and output to the 29# specified file 30# --metadata_hash_file if defined, generate a metadata hash and output to the 31# specified file 32# 33# Sign command arguments: 34# --unsigned_payload the input unsigned payload to insert the signatures 35# --payload the output signed payload 36# --signature_size signature sizes in bytes in the following format: 37# "size1:size2[:...]" 38# --payload_signature_file the payload signature files in the following 39# format: 40# "payload_signature1:payload_signature2[:...]" 41# --metadata_signature_file the metadata signature files in the following 42# format: 43# "metadata_signature1:metadata_signature2[:...]" 44# --metadata_size_file if defined, generate a file containing the size of 45# the signed payload metadata in bytes to the 46# specified file 47# Note that the number of signature sizes and payload signatures have to match. 48# 49# Properties command arguments: 50# --payload the input signed or unsigned payload 51# --properties_file the output path where to write the properties, or 52# '-' for stdout. 53 54 55# Exit codes: 56EX_UNSUPPORTED_DELTA=100 57 58warn() { 59 echo "brillo_update_payload: warning: $*" >&2 60} 61 62die() { 63 echo "brillo_update_payload: error: $*" >&2 64 exit 1 65} 66 67# Loads shflags. We first look at the default install location; then look for 68# crosutils (chroot); finally check our own directory (au-generator zipfile). 69load_shflags() { 70 local my_dir="$(dirname "$(readlink -f "$0")")" 71 local path 72 for path in /usr/share/misc {/usr/lib/crosutils,"${my_dir}"}/lib/shflags; do 73 if [[ -r "${path}/shflags" ]]; then 74 . "${path}/shflags" || die "Could not load ${path}/shflags." 75 return 76 fi 77 done 78 die "Could not find shflags." 79} 80 81load_shflags 82 83HELP_GENERATE="generate: Generate an unsigned update payload." 84HELP_HASH="hash: Generate the hashes of the unsigned payload and metadata used \ 85for signing." 86HELP_SIGN="sign: Insert the signatures into the unsigned payload." 87HELP_PROPERTIES="properties: Extract payload properties to a file." 88 89usage() { 90 echo "Supported commands:" 91 echo 92 echo "${HELP_GENERATE}" 93 echo "${HELP_HASH}" 94 echo "${HELP_SIGN}" 95 echo "${HELP_PROPERTIES}" 96 echo 97 echo "Use: \"$0 <command> --help\" for more options." 98} 99 100# Check that a command is specified. 101if [[ $# -lt 1 ]]; then 102 echo "Please specify a command [generate|hash|sign|properties]" 103 exit 1 104fi 105 106# Parse command. 107COMMAND="${1:-}" 108shift 109 110case "${COMMAND}" in 111 generate) 112 FLAGS_HELP="${HELP_GENERATE}" 113 ;; 114 115 hash) 116 FLAGS_HELP="${HELP_HASH}" 117 ;; 118 119 sign) 120 FLAGS_HELP="${HELP_SIGN}" 121 ;; 122 123 properties) 124 FLAGS_HELP="${HELP_PROPERTIES}" 125 ;; 126 *) 127 echo "Unrecognized command: \"${COMMAND}\"" >&2 128 usage >&2 129 exit 1 130 ;; 131esac 132 133# Flags 134FLAGS_HELP="Usage: $0 ${COMMAND} [flags] 135${FLAGS_HELP}" 136 137if [[ "${COMMAND}" == "generate" ]]; then 138 DEFINE_string payload "" \ 139 "Path to output the generated unsigned payload file." 140 DEFINE_string target_image "" \ 141 "Path to the target image that should be sent to clients." 142 DEFINE_string source_image "" \ 143 "Optional: Path to a source image. If specified, this makes a delta update." 144 DEFINE_string metadata_size_file "" \ 145 "Optional: Path to output metadata size." 146fi 147if [[ "${COMMAND}" == "hash" || "${COMMAND}" == "sign" ]]; then 148 DEFINE_string unsigned_payload "" "Path to the input unsigned payload." 149 DEFINE_string signature_size "" \ 150 "Signature sizes in bytes in the following format: size1:size2[:...]" 151fi 152if [[ "${COMMAND}" == "hash" ]]; then 153 DEFINE_string metadata_hash_file "" \ 154 "Optional: Path to output metadata hash file." 155 DEFINE_string payload_hash_file "" \ 156 "Optional: Path to output payload hash file." 157fi 158if [[ "${COMMAND}" == "sign" ]]; then 159 DEFINE_string payload "" \ 160 "Path to output the generated unsigned payload file." 161 DEFINE_string metadata_signature_file "" \ 162 "The metatada signatures in the following format: \ 163metadata_signature1:metadata_signature2[:...]" 164 DEFINE_string payload_signature_file "" \ 165 "The payload signatures in the following format: \ 166payload_signature1:payload_signature2[:...]" 167 DEFINE_string metadata_size_file "" \ 168 "Optional: Path to output metadata size." 169fi 170if [[ "${COMMAND}" == "properties" ]]; then 171 DEFINE_string payload "" \ 172 "Path to the input signed or unsigned payload file." 173 DEFINE_string properties_file "-" \ 174 "Path to output the extracted property files. If '-' is passed stdout will \ 175be used." 176fi 177 178DEFINE_string work_dir "${TMPDIR:-/tmp}" "Where to dump temporary files." 179 180# Parse command line flag arguments 181FLAGS "$@" || exit 1 182eval set -- "${FLAGS_ARGV}" 183set -e 184 185# Override the TMPDIR with the passed work_dir flags, which anyway defaults to 186# ${TMPDIR}. 187TMPDIR="${FLAGS_work_dir}" 188export TMPDIR 189 190# Associative arrays from partition name to file in the source and target 191# images. The size of the updated area must be the size of the file. 192declare -A SRC_PARTITIONS 193declare -A DST_PARTITIONS 194 195# Associative arrays for the .map files associated with each src/dst partition 196# file in SRC_PARTITIONS and DST_PARTITIONS. 197declare -A SRC_PARTITIONS_MAP 198declare -A DST_PARTITIONS_MAP 199 200# List of partition names in order. 201declare -a PARTITIONS_ORDER 202 203# A list of temporary files to remove during cleanup. 204CLEANUP_FILES=() 205 206# Global options to force the version of the payload. 207FORCE_MAJOR_VERSION="" 208FORCE_MINOR_VERSION="" 209 210# Path to the postinstall config file in target image if exists. 211POSTINSTALL_CONFIG_FILE="" 212 213# The fingerprint of zlib in the source image. 214ZLIB_FINGERPRINT="" 215 216# read_option_int <file.txt> <option_key> [default_value] 217# 218# Reads the unsigned integer value associated with |option_key| in a key=value 219# file |file.txt|. Prints the read value if found and valid, otherwise prints 220# the |default_value|. 221read_option_uint() { 222 local file_txt="$1" 223 local option_key="$2" 224 local default_value="${3:-}" 225 local value 226 if value=$(look "${option_key}=" "${file_txt}" | tail -n 1); then 227 if value=$(echo "${value}" | cut -f 2- -d "=" | grep -E "^[0-9]+$"); then 228 echo "${value}" 229 return 230 fi 231 fi 232 echo "${default_value}" 233} 234 235# truncate_file <file_path> <file_size> 236# 237# Truncate the given |file_path| to |file_size| using perl. 238# The truncate binary might not be available. 239truncate_file() { 240 local file_path="$1" 241 local file_size="$2" 242 perl -e "open(FILE, \"+<\", \$ARGV[0]); \ 243 truncate(FILE, ${file_size}); \ 244 close(FILE);" "${file_path}" 245} 246 247# Create a temporary file in the work_dir with an optional pattern name. 248# Prints the name of the newly created file. 249create_tempfile() { 250 local pattern="${1:-tempfile.XXXXXX}" 251 mktemp --tmpdir="${FLAGS_work_dir}" "${pattern}" 252} 253 254cleanup() { 255 local err="" 256 rm -f "${CLEANUP_FILES[@]}" || err=1 257 258 # If we are cleaning up after an error, or if we got an error during 259 # cleanup (even if we eventually succeeded) return a non-zero exit 260 # code. This triggers additional logging in most environments that call 261 # this script. 262 if [[ -n "${err}" ]]; then 263 die "Cleanup encountered an error." 264 fi 265} 266 267cleanup_on_error() { 268 trap - INT TERM ERR EXIT 269 cleanup 270 die "Cleanup success after an error." 271} 272 273cleanup_on_exit() { 274 trap - INT TERM ERR EXIT 275 cleanup 276} 277 278trap cleanup_on_error INT TERM ERR 279trap cleanup_on_exit EXIT 280 281 282# extract_image <image> <partitions_array> [partitions_order] 283# 284# Detect the format of the |image| file and extract its updatable partitions 285# into new temporary files. Add the list of partition names and its files to the 286# associative array passed in |partitions_array|. If |partitions_order| is 287# passed, set it to list of partition names in order. 288extract_image() { 289 local image="$1" 290 291 # Brillo images are zip files. We detect the 4-byte magic header of the zip 292 # file. 293 local magic=$(head --bytes=4 "${image}" | hexdump -e '1/1 "%.2x"') 294 if [[ "${magic}" == "504b0304" ]]; then 295 echo "Detected .zip file, extracting Brillo image." 296 extract_image_brillo "$@" 297 return 298 fi 299 300 # Chrome OS images are GPT partitioned disks. We should have the cgpt binary 301 # bundled here and we will use it to extract the partitions, so the GPT 302 # headers must be valid. 303 if cgpt show -q -n "${image}" >/dev/null; then 304 echo "Detected GPT image, extracting Chrome OS image." 305 extract_image_cros "$@" 306 return 307 fi 308 309 die "Couldn't detect the image format of ${image}" 310} 311 312# extract_image_cros <image.bin> <partitions_array> [partitions_order] 313# 314# Extract Chromium OS recovery images into new temporary files. 315extract_image_cros() { 316 local image="$1" 317 local partitions_array="$2" 318 local partitions_order="${3:-}" 319 320 local kernel root 321 kernel=$(create_tempfile "kernel.bin.XXXXXX") 322 CLEANUP_FILES+=("${kernel}") 323 root=$(create_tempfile "root.bin.XXXXXX") 324 CLEANUP_FILES+=("${root}") 325 326 cros_generate_update_payload --extract \ 327 --image "${image}" \ 328 --kern_path "${kernel}" --root_path "${root}" \ 329 --work_dir "${FLAGS_work_dir}" --outside_chroot 330 331 # Chrome OS uses major_version 1 payloads for all versions, even if the 332 # updater supports a newer major version. 333 FORCE_MAJOR_VERSION="1" 334 335 if [[ "${partitions_array}" == "SRC_PARTITIONS" ]]; then 336 # Copy from zlib_fingerprint in source image to stdout. 337 ZLIB_FINGERPRINT=$(e2cp "${root}":/etc/zlib_fingerprint -) 338 fi 339 340 # When generating legacy Chrome OS images, we need to use "boot" and "system" 341 # for the partition names to be compatible with updating Brillo devices with 342 # Chrome OS images. 343 eval ${partitions_array}[boot]=\""${kernel}"\" 344 eval ${partitions_array}[system]=\""${root}"\" 345 346 if [[ -n "${partitions_order}" ]]; then 347 eval "${partitions_order}=( \"system\" \"boot\" )" 348 fi 349 350 local part varname 351 for part in boot system; do 352 varname="${partitions_array}[${part}]" 353 printf "md5sum of %s: " "${varname}" 354 md5sum "${!varname}" 355 done 356} 357 358# extract_image_brillo <target_files.zip> <partitions_array> [partitions_order] 359# 360# Extract the A/B updated partitions from a Brillo target_files zip file into 361# new temporary files. 362extract_image_brillo() { 363 local image="$1" 364 local partitions_array="$2" 365 local partitions_order="${3:-}" 366 367 local partitions=( "boot" "system" ) 368 local ab_partitions_list 369 ab_partitions_list=$(create_tempfile "ab_partitions_list.XXXXXX") 370 CLEANUP_FILES+=("${ab_partitions_list}") 371 if unzip -p "${image}" "META/ab_partitions.txt" >"${ab_partitions_list}"; then 372 if grep -v -E '^[a-zA-Z0-9_-]*$' "${ab_partitions_list}" >&2; then 373 die "Invalid partition names found in the partition list." 374 fi 375 partitions=($(cat "${ab_partitions_list}")) 376 if [[ ${#partitions[@]} -eq 0 ]]; then 377 die "The list of partitions is empty. Can't generate a payload." 378 fi 379 else 380 warn "No ab_partitions.txt found. Using default." 381 fi 382 echo "List of A/B partitions: ${partitions[@]}" 383 384 if [[ -n "${partitions_order}" ]]; then 385 eval "${partitions_order}=(${partitions[@]})" 386 fi 387 388 # All Brillo updaters support major version 2. 389 FORCE_MAJOR_VERSION="2" 390 391 if [[ "${partitions_array}" == "SRC_PARTITIONS" ]]; then 392 # Source image 393 local ue_config=$(create_tempfile "ue_config.XXXXXX") 394 CLEANUP_FILES+=("${ue_config}") 395 if ! unzip -p "${image}" "META/update_engine_config.txt" \ 396 >"${ue_config}"; then 397 warn "No update_engine_config.txt found. Assuming pre-release image, \ 398using payload minor version 2" 399 fi 400 # For delta payloads, we use the major and minor version supported by the 401 # old updater. 402 FORCE_MINOR_VERSION=$(read_option_uint "${ue_config}" \ 403 "PAYLOAD_MINOR_VERSION" 2) 404 FORCE_MAJOR_VERSION=$(read_option_uint "${ue_config}" \ 405 "PAYLOAD_MAJOR_VERSION" 2) 406 407 # Brillo support for deltas started with minor version 3. 408 if [[ "${FORCE_MINOR_VERSION}" -le 2 ]]; then 409 warn "No delta support from minor version ${FORCE_MINOR_VERSION}. \ 410Disabling deltas for this source version." 411 exit ${EX_UNSUPPORTED_DELTA} 412 fi 413 414 if [[ "${FORCE_MINOR_VERSION}" -ge 4 ]]; then 415 ZLIB_FINGERPRINT=$(unzip -p "${image}" "META/zlib_fingerprint.txt") 416 fi 417 else 418 # Target image 419 local postinstall_config=$(create_tempfile "postinstall_config.XXXXXX") 420 CLEANUP_FILES+=("${postinstall_config}") 421 if unzip -p "${image}" "META/postinstall_config.txt" \ 422 >"${postinstall_config}"; then 423 POSTINSTALL_CONFIG_FILE="${postinstall_config}" 424 fi 425 fi 426 427 local part part_file temp_raw filesize 428 for part in "${partitions[@]}"; do 429 part_file=$(create_tempfile "${part}.img.XXXXXX") 430 CLEANUP_FILES+=("${part_file}") 431 unzip -p "${image}" "IMAGES/${part}.img" >"${part_file}" 432 433 # If the partition is stored as an Android sparse image file, we need to 434 # convert them to a raw image for the update. 435 local magic=$(head --bytes=4 "${part_file}" | hexdump -e '1/1 "%.2x"') 436 if [[ "${magic}" == "3aff26ed" ]]; then 437 temp_raw=$(create_tempfile "${part}.raw.XXXXXX") 438 CLEANUP_FILES+=("${temp_raw}") 439 echo "Converting Android sparse image ${part}.img to RAW." 440 simg2img "${part_file}" "${temp_raw}" 441 # At this point, we can drop the contents of the old part_file file, but 442 # we can't delete the file because it will be deleted in cleanup. 443 true >"${part_file}" 444 part_file="${temp_raw}" 445 fi 446 447 # Extract the .map file (if one is available). 448 part_map_file=$(create_tempfile "${part}.map.XXXXXX") 449 CLEANUP_FILES+=("${part_map_file}") 450 unzip -p "${image}" "IMAGES/${part}.map" >"${part_map_file}" || \ 451 part_map_file="" 452 453 # delta_generator only supports images multiple of 4 KiB. For target images 454 # we pad the data with zeros if needed, but for source images we truncate 455 # down the data since the last block of the old image could be padded on 456 # disk with unknown data. 457 filesize=$(stat -c%s "${part_file}") 458 if [[ $(( filesize % 4096 )) -ne 0 ]]; then 459 if [[ "${partitions_array}" == "SRC_PARTITIONS" ]]; then 460 echo "Rounding DOWN partition ${part}.img to a multiple of 4 KiB." 461 : $(( filesize = filesize & -4096 )) 462 else 463 echo "Rounding UP partition ${part}.img to a multiple of 4 KiB." 464 : $(( filesize = (filesize + 4095) & -4096 )) 465 fi 466 truncate_file "${part_file}" "${filesize}" 467 fi 468 469 eval "${partitions_array}[\"${part}\"]=\"${part_file}\"" 470 eval "${partitions_array}_MAP[\"${part}\"]=\"${part_map_file}\"" 471 echo "Extracted ${partitions_array}[${part}]: ${filesize} bytes" 472 done 473} 474 475validate_generate() { 476 [[ -n "${FLAGS_payload}" ]] || 477 die "You must specify an output filename with --payload FILENAME" 478 479 [[ -n "${FLAGS_target_image}" ]] || 480 die "You must specify a target image with --target_image FILENAME" 481} 482 483cmd_generate() { 484 local payload_type="delta" 485 if [[ -z "${FLAGS_source_image}" ]]; then 486 payload_type="full" 487 fi 488 489 echo "Extracting images for ${payload_type} update." 490 491 extract_image "${FLAGS_target_image}" DST_PARTITIONS PARTITIONS_ORDER 492 if [[ "${payload_type}" == "delta" ]]; then 493 extract_image "${FLAGS_source_image}" SRC_PARTITIONS 494 fi 495 496 echo "Generating ${payload_type} update." 497 # Common payload args: 498 GENERATOR_ARGS=( -out_file="${FLAGS_payload}" ) 499 500 local part old_partitions="" new_partitions="" partition_names="" 501 local old_mapfiles="" new_mapfiles="" 502 for part in "${PARTITIONS_ORDER[@]}"; do 503 if [[ -n "${partition_names}" ]]; then 504 partition_names+=":" 505 new_partitions+=":" 506 old_partitions+=":" 507 new_mapfiles+=":" 508 old_mapfiles+=":" 509 fi 510 partition_names+="${part}" 511 new_partitions+="${DST_PARTITIONS[${part}]}" 512 old_partitions+="${SRC_PARTITIONS[${part}]:-}" 513 new_mapfiles+="${DST_PARTITIONS_MAP[${part}]:-}" 514 old_mapfiles+="${SRC_PARTITIONS_MAP[${part}]:-}" 515 done 516 517 # Target image args: 518 GENERATOR_ARGS+=( 519 -partition_names="${partition_names}" 520 -new_partitions="${new_partitions}" 521 -new_mapfiles="${new_mapfiles}" 522 ) 523 524 if [[ "${payload_type}" == "delta" ]]; then 525 # Source image args: 526 GENERATOR_ARGS+=( 527 -old_partitions="${old_partitions}" 528 -old_mapfiles="${old_mapfiles}" 529 ) 530 if [[ -n "${FORCE_MINOR_VERSION}" ]]; then 531 GENERATOR_ARGS+=( --minor_version="${FORCE_MINOR_VERSION}" ) 532 fi 533 if [[ -n "${ZLIB_FINGERPRINT}" ]]; then 534 GENERATOR_ARGS+=( --zlib_fingerprint="${ZLIB_FINGERPRINT}" ) 535 fi 536 fi 537 538 if [[ -n "${FORCE_MAJOR_VERSION}" ]]; then 539 GENERATOR_ARGS+=( --major_version="${FORCE_MAJOR_VERSION}" ) 540 fi 541 542 if [[ -n "${FLAGS_metadata_size_file}" ]]; then 543 GENERATOR_ARGS+=( --out_metadata_size_file="${FLAGS_metadata_size_file}" ) 544 fi 545 546 if [[ -n "${POSTINSTALL_CONFIG_FILE}" ]]; then 547 GENERATOR_ARGS+=( 548 --new_postinstall_config_file="${POSTINSTALL_CONFIG_FILE}" 549 ) 550 fi 551 552 echo "Running delta_generator with args: ${GENERATOR_ARGS[@]}" 553 "${GENERATOR}" "${GENERATOR_ARGS[@]}" 554 555 echo "Done generating ${payload_type} update." 556} 557 558validate_hash() { 559 [[ -n "${FLAGS_signature_size}" ]] || 560 die "You must specify signature size with --signature_size SIZES" 561 562 [[ -n "${FLAGS_unsigned_payload}" ]] || 563 die "You must specify the input unsigned payload with \ 564--unsigned_payload FILENAME" 565 566 [[ -n "${FLAGS_payload_hash_file}" ]] || 567 die "You must specify --payload_hash_file FILENAME" 568 569 [[ -n "${FLAGS_metadata_hash_file}" ]] || 570 die "You must specify --metadata_hash_file FILENAME" 571} 572 573cmd_hash() { 574 "${GENERATOR}" \ 575 -in_file="${FLAGS_unsigned_payload}" \ 576 -signature_size="${FLAGS_signature_size}" \ 577 -out_hash_file="${FLAGS_payload_hash_file}" \ 578 -out_metadata_hash_file="${FLAGS_metadata_hash_file}" 579 580 echo "Done generating hash." 581} 582 583validate_sign() { 584 [[ -n "${FLAGS_signature_size}" ]] || 585 die "You must specify signature size with --signature_size SIZES" 586 587 [[ -n "${FLAGS_unsigned_payload}" ]] || 588 die "You must specify the input unsigned payload with \ 589--unsigned_payload FILENAME" 590 591 [[ -n "${FLAGS_payload}" ]] || 592 die "You must specify the output signed payload with --payload FILENAME" 593 594 [[ -n "${FLAGS_payload_signature_file}" ]] || 595 die "You must specify the payload signature file with \ 596--payload_signature_file SIGNATURES" 597 598 [[ -n "${FLAGS_metadata_signature_file}" ]] || 599 die "You must specify the metadata signature file with \ 600--metadata_signature_file SIGNATURES" 601} 602 603cmd_sign() { 604 GENERATOR_ARGS=( 605 -in_file="${FLAGS_unsigned_payload}" 606 -signature_size="${FLAGS_signature_size}" 607 -signature_file="${FLAGS_payload_signature_file}" 608 -metadata_signature_file="${FLAGS_metadata_signature_file}" 609 -out_file="${FLAGS_payload}" 610 ) 611 612 if [[ -n "${FLAGS_metadata_size_file}" ]]; then 613 GENERATOR_ARGS+=( --out_metadata_size_file="${FLAGS_metadata_size_file}" ) 614 fi 615 616 "${GENERATOR}" "${GENERATOR_ARGS[@]}" 617 echo "Done signing payload." 618} 619 620validate_properties() { 621 [[ -n "${FLAGS_payload}" ]] || 622 die "You must specify the payload file with --payload FILENAME" 623 624 [[ -n "${FLAGS_properties_file}" ]] || 625 die "You must specify a non empty --properties_file FILENAME" 626} 627 628cmd_properties() { 629 "${GENERATOR}" \ 630 -in_file="${FLAGS_payload}" \ 631 -properties_file="${FLAGS_properties_file}" 632} 633 634# Sanity check that the real generator exists: 635GENERATOR="$(which delta_generator || true)" 636[[ -x "${GENERATOR}" ]] || die "can't find delta_generator" 637 638case "$COMMAND" in 639 generate) validate_generate 640 cmd_generate 641 ;; 642 hash) validate_hash 643 cmd_hash 644 ;; 645 sign) validate_sign 646 cmd_sign 647 ;; 648 properties) validate_properties 649 cmd_properties 650 ;; 651esac 652