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