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 # Create a temporary file in the work_dir with an optional pattern name. 223 # Prints the name of the newly created file. 224 create_tempfile() { 225 local pattern="${1:-tempfile.XXXXXX}" 226 mktemp --tmpdir="${FLAGS_work_dir}" "${pattern}" 227 } 228 229 cleanup() { 230 local err="" 231 rm -f "${CLEANUP_FILES[@]}" || err=1 232 233 # If we are cleaning up after an error, or if we got an error during 234 # cleanup (even if we eventually succeeded) return a non-zero exit 235 # code. This triggers additional logging in most environments that call 236 # this script. 237 if [[ -n "${err}" ]]; then 238 die "Cleanup encountered an error." 239 fi 240 } 241 242 cleanup_on_error() { 243 trap - INT TERM ERR EXIT 244 cleanup 245 die "Cleanup success after an error." 246 } 247 248 cleanup_on_exit() { 249 trap - INT TERM ERR EXIT 250 cleanup 251 } 252 253 trap cleanup_on_error INT TERM ERR 254 trap cleanup_on_exit EXIT 255 256 257 # extract_image <image> <partitions_array> 258 # 259 # Detect the format of the |image| file and extract its updatable partitions 260 # into new temporary files. Add the list of partition names and its files to the 261 # associative array passed in |partitions_array|. 262 extract_image() { 263 local image="$1" 264 265 # Brillo images are zip files. We detect the 4-byte magic header of the zip 266 # file. 267 local magic=$(head --bytes=4 "${image}" | hexdump -e '1/1 "%.2x"') 268 if [[ "${magic}" == "504b0304" ]]; then 269 echo "Detected .zip file, extracting Brillo image." 270 extract_image_brillo "$@" 271 return 272 fi 273 274 # Chrome OS images are GPT partitioned disks. We should have the cgpt binary 275 # bundled here and we will use it to extract the partitions, so the GPT 276 # headers must be valid. 277 if cgpt show -q -n "${image}" >/dev/null; then 278 echo "Detected GPT image, extracting Chrome OS image." 279 extract_image_cros "$@" 280 return 281 fi 282 283 die "Couldn't detect the image format of ${image}" 284 } 285 286 # extract_image_cros <image.bin> <partitions_array> 287 # 288 # Extract Chromium OS recovery images into new temporary files. 289 extract_image_cros() { 290 local image="$1" 291 local partitions_array="$2" 292 293 local kernel root 294 kernel=$(create_tempfile "kernel.bin.XXXXXX") 295 CLEANUP_FILES+=("${kernel}") 296 root=$(create_tempfile "root.bin.XXXXXX") 297 CLEANUP_FILES+=("${root}") 298 299 cros_generate_update_payload --extract \ 300 --image "${image}" \ 301 --kern_path "${kernel}" --root_path "${root}" \ 302 --work_dir "${FLAGS_work_dir}" --outside_chroot 303 304 # Chrome OS uses major_version 1 payloads for all versions, even if the 305 # updater supports a newer major version. 306 FORCE_MAJOR_VERSION="1" 307 308 if [[ "${partitions_array}" == "SRC_PARTITIONS" ]]; then 309 # Copy from zlib_fingerprint in source image to stdout. 310 ZLIB_FINGERPRINT=$(e2cp "${root}":/etc/zlib_fingerprint -) 311 fi 312 313 # When generating legacy Chrome OS images, we need to use "boot" and "system" 314 # for the partition names to be compatible with updating Brillo devices with 315 # Chrome OS images. 316 eval ${partitions_array}[boot]=\""${kernel}"\" 317 eval ${partitions_array}[system]=\""${root}"\" 318 319 local part varname 320 for part in boot system; do 321 varname="${partitions_array}[${part}]" 322 printf "md5sum of %s: " "${varname}" 323 md5sum "${!varname}" 324 done 325 } 326 327 # extract_image_brillo <target_files.zip> <partitions_array> 328 # 329 # Extract the A/B updated partitions from a Brillo target_files zip file into 330 # new temporary files. 331 extract_image_brillo() { 332 local image="$1" 333 local partitions_array="$2" 334 335 local partitions=( "boot" "system" ) 336 local ab_partitions_list 337 ab_partitions_list=$(create_tempfile "ab_partitions_list.XXXXXX") 338 CLEANUP_FILES+=("${ab_partitions_list}") 339 if unzip -p "${image}" "META/ab_partitions.txt" >"${ab_partitions_list}"; then 340 if grep -v -E '^[a-zA-Z0-9_-]*$' "${ab_partitions_list}" >&2; then 341 die "Invalid partition names found in the partition list." 342 fi 343 partitions=($(cat "${ab_partitions_list}")) 344 if [[ ${#partitions[@]} -eq 0 ]]; then 345 die "The list of partitions is empty. Can't generate a payload." 346 fi 347 else 348 warn "No ab_partitions.txt found. Using default." 349 fi 350 echo "List of A/B partitions: ${partitions[@]}" 351 352 # All Brillo updaters support major version 2. 353 FORCE_MAJOR_VERSION="2" 354 355 if [[ "${partitions_array}" == "SRC_PARTITIONS" ]]; then 356 # Source image 357 local ue_config=$(create_tempfile "ue_config.XXXXXX") 358 CLEANUP_FILES+=("${ue_config}") 359 if ! unzip -p "${image}" "META/update_engine_config.txt" \ 360 >"${ue_config}"; then 361 warn "No update_engine_config.txt found. Assuming pre-release image, \ 362 using payload minor version 2" 363 fi 364 # For delta payloads, we use the major and minor version supported by the 365 # old updater. 366 FORCE_MINOR_VERSION=$(read_option_uint "${ue_config}" \ 367 "PAYLOAD_MINOR_VERSION" 2) 368 FORCE_MAJOR_VERSION=$(read_option_uint "${ue_config}" \ 369 "PAYLOAD_MAJOR_VERSION" 2) 370 371 # Brillo support for deltas started with minor version 3. 372 if [[ "${FORCE_MINOR_VERSION}" -le 2 ]]; then 373 warn "No delta support from minor version ${FORCE_MINOR_VERSION}. \ 374 Disabling deltas for this source version." 375 exit ${EX_UNSUPPORTED_DELTA} 376 fi 377 378 if [[ "${FORCE_MINOR_VERSION}" -ge 4 ]]; then 379 ZLIB_FINGERPRINT=$(unzip -p "${image}" "META/zlib_fingerprint.txt") 380 fi 381 else 382 # Target image 383 local postinstall_config=$(create_tempfile "postinstall_config.XXXXXX") 384 CLEANUP_FILES+=("${postinstall_config}") 385 if unzip -p "${image}" "META/postinstall_config.txt" \ 386 >"${postinstall_config}"; then 387 POSTINSTALL_CONFIG_FILE="${postinstall_config}" 388 fi 389 fi 390 391 local part part_file temp_raw filesize 392 for part in "${partitions[@]}"; do 393 part_file=$(create_tempfile "${part}.img.XXXXXX") 394 CLEANUP_FILES+=("${part_file}") 395 unzip -p "${image}" "IMAGES/${part}.img" >"${part_file}" 396 397 # If the partition is stored as an Android sparse image file, we need to 398 # convert them to a raw image for the update. 399 local magic=$(head --bytes=4 "${part_file}" | hexdump -e '1/1 "%.2x"') 400 if [[ "${magic}" == "3aff26ed" ]]; then 401 temp_raw=$(create_tempfile "${part}.raw.XXXXXX") 402 CLEANUP_FILES+=("${temp_raw}") 403 echo "Converting Android sparse image ${part}.img to RAW." 404 simg2img "${part_file}" "${temp_raw}" 405 # At this point, we can drop the contents of the old part_file file, but 406 # we can't delete the file because it will be deleted in cleanup. 407 true >"${part_file}" 408 part_file="${temp_raw}" 409 fi 410 411 # delta_generator only supports images multiple of 4 KiB. For target images 412 # we pad the data with zeros if needed, but for source images we truncate 413 # down the data since the last block of the old image could be padded on 414 # disk with unknown data. 415 filesize=$(stat -c%s "${part_file}") 416 if [[ $(( filesize % 4096 )) -ne 0 ]]; then 417 if [[ "${partitions_array}" == "SRC_PARTITIONS" ]]; then 418 echo "Rounding DOWN partition ${part}.img to a multiple of 4 KiB." 419 : $(( filesize = filesize & -4096 )) 420 else 421 echo "Rounding UP partition ${part}.img to a multiple of 4 KiB." 422 : $(( filesize = (filesize + 4095) & -4096 )) 423 fi 424 truncate --size="${filesize}" "${part_file}" 425 fi 426 427 eval "${partitions_array}[\"${part}\"]=\"${part_file}\"" 428 echo "Extracted ${partitions_array}[${part}]: ${filesize} bytes" 429 done 430 } 431 432 validate_generate() { 433 [[ -n "${FLAGS_payload}" ]] || 434 die "Error: you must specify an output filename with --payload FILENAME" 435 436 [[ -n "${FLAGS_target_image}" ]] || 437 die "Error: you must specify a target image with --target_image FILENAME" 438 } 439 440 cmd_generate() { 441 local payload_type="delta" 442 if [[ -z "${FLAGS_source_image}" ]]; then 443 payload_type="full" 444 fi 445 446 echo "Extracting images for ${payload_type} update." 447 448 extract_image "${FLAGS_target_image}" DST_PARTITIONS 449 if [[ "${payload_type}" == "delta" ]]; then 450 extract_image "${FLAGS_source_image}" SRC_PARTITIONS 451 fi 452 453 echo "Generating ${payload_type} update." 454 # Common payload args: 455 GENERATOR_ARGS=( -out_file="${FLAGS_payload}" ) 456 457 local part old_partitions="" new_partitions="" partition_names="" 458 for part in "${!DST_PARTITIONS[@]}"; do 459 if [[ -n "${partition_names}" ]]; then 460 partition_names+=":" 461 new_partitions+=":" 462 old_partitions+=":" 463 fi 464 partition_names+="${part}" 465 new_partitions+="${DST_PARTITIONS[${part}]}" 466 old_partitions+="${SRC_PARTITIONS[${part}]:-}" 467 done 468 469 # Target image args: 470 GENERATOR_ARGS+=( 471 -partition_names="${partition_names}" 472 -new_partitions="${new_partitions}" 473 ) 474 475 if [[ "${payload_type}" == "delta" ]]; then 476 # Source image args: 477 GENERATOR_ARGS+=( 478 -old_partitions="${old_partitions}" 479 ) 480 if [[ -n "${FORCE_MINOR_VERSION}" ]]; then 481 GENERATOR_ARGS+=( --minor_version="${FORCE_MINOR_VERSION}" ) 482 fi 483 if [[ -n "${ZLIB_FINGERPRINT}" ]]; then 484 GENERATOR_ARGS+=( --zlib_fingerprint="${ZLIB_FINGERPRINT}" ) 485 fi 486 fi 487 488 if [[ -n "${FORCE_MAJOR_VERSION}" ]]; then 489 GENERATOR_ARGS+=( --major_version="${FORCE_MAJOR_VERSION}" ) 490 fi 491 492 if [[ -n "${FLAGS_metadata_size_file}" ]]; then 493 GENERATOR_ARGS+=( --out_metadata_size_file="${FLAGS_metadata_size_file}" ) 494 fi 495 496 if [[ -n "${POSTINSTALL_CONFIG_FILE}" ]]; then 497 GENERATOR_ARGS+=( 498 --new_postinstall_config_file="${POSTINSTALL_CONFIG_FILE}" 499 ) 500 fi 501 502 echo "Running delta_generator with args: ${GENERATOR_ARGS[@]}" 503 "${GENERATOR}" "${GENERATOR_ARGS[@]}" 504 505 echo "Done generating ${payload_type} update." 506 } 507 508 validate_hash() { 509 [[ -n "${FLAGS_signature_size}" ]] || 510 die "Error: you must specify signature size with --signature_size SIZES" 511 512 [[ -n "${FLAGS_unsigned_payload}" ]] || 513 die "Error: you must specify the input unsigned payload with \ 514 --unsigned_payload FILENAME" 515 516 [[ -n "${FLAGS_payload_hash_file}" ]] || 517 die "Error: you must specify --payload_hash_file FILENAME" 518 519 [[ -n "${FLAGS_metadata_hash_file}" ]] || 520 die "Error: you must specify --metadata_hash_file FILENAME" 521 } 522 523 cmd_hash() { 524 "${GENERATOR}" \ 525 -in_file="${FLAGS_unsigned_payload}" \ 526 -signature_size="${FLAGS_signature_size}" \ 527 -out_hash_file="${FLAGS_payload_hash_file}" \ 528 -out_metadata_hash_file="${FLAGS_metadata_hash_file}" 529 530 echo "Done generating hash." 531 } 532 533 validate_sign() { 534 [[ -n "${FLAGS_signature_size}" ]] || 535 die "Error: you must specify signature size with --signature_size SIZES" 536 537 [[ -n "${FLAGS_unsigned_payload}" ]] || 538 die "Error: you must specify the input unsigned payload with \ 539 --unsigned_payload FILENAME" 540 541 [[ -n "${FLAGS_payload}" ]] || 542 die "Error: you must specify the output signed payload with \ 543 --payload FILENAME" 544 545 [[ -n "${FLAGS_payload_signature_file}" ]] || 546 die "Error: you must specify the payload signature file with \ 547 --payload_signature_file SIGNATURES" 548 549 [[ -n "${FLAGS_metadata_signature_file}" ]] || 550 die "Error: you must specify the metadata signature file with \ 551 --metadata_signature_file SIGNATURES" 552 } 553 554 cmd_sign() { 555 GENERATOR_ARGS=( 556 -in_file="${FLAGS_unsigned_payload}" 557 -signature_size="${FLAGS_signature_size}" 558 -signature_file="${FLAGS_payload_signature_file}" 559 -metadata_signature_file="${FLAGS_metadata_signature_file}" 560 -out_file="${FLAGS_payload}" 561 ) 562 563 if [[ -n "${FLAGS_metadata_size_file}" ]]; then 564 GENERATOR_ARGS+=( --out_metadata_size_file="${FLAGS_metadata_size_file}" ) 565 fi 566 567 "${GENERATOR}" "${GENERATOR_ARGS[@]}" 568 echo "Done signing payload." 569 } 570 571 validate_properties() { 572 [[ -n "${FLAGS_payload}" ]] || 573 die "Error: you must specify the payload file with --payload FILENAME" 574 575 [[ -n "${FLAGS_properties_file}" ]] || 576 die "Error: you must specify a non empty --properties_file FILENAME" 577 } 578 579 cmd_properties() { 580 "${GENERATOR}" \ 581 -in_file="${FLAGS_payload}" \ 582 -properties_file="${FLAGS_properties_file}" 583 } 584 585 # Sanity check that the real generator exists: 586 GENERATOR="$(which delta_generator)" 587 [[ -x "${GENERATOR}" ]] || die "can't find delta_generator" 588 589 case "$COMMAND" in 590 generate) validate_generate 591 cmd_generate 592 ;; 593 hash) validate_hash 594 cmd_hash 595 ;; 596 sign) validate_sign 597 cmd_sign 598 ;; 599 properties) validate_properties 600 cmd_properties 601 ;; 602 esac 603
