paycheck.py revision 43116436524744f065ff29cfbe31e045339a1204
1#!/usr/bin/python 2# 3# Copyright (c) 2013 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"""Command-line tool for checking and applying Chrome OS update payloads.""" 8 9import optparse 10import os 11import sys 12 13# pylint: disable=F0401 14lib_dir = os.path.join(os.path.dirname(__file__), 'lib') 15if os.path.exists(lib_dir) and os.path.isdir(lib_dir): 16 sys.path.insert(1, lib_dir) 17import update_payload 18 19 20# The default sizes of partitions, based on current partitioning practice. 21_DEFAULT_ROOTFS_PART_SIZE = 2 * 1024 * 1024 * 1024 22_DEFAULT_KERNEL_PART_SIZE = 16 * 1024 * 1024 23 24_TYPE_FULL = 'full' 25_TYPE_DELTA = 'delta' 26 27 28def ParseArguments(argv): 29 """Parse and validate command-line arguments. 30 31 Args: 32 argv: command-line arguments to parse (excluding the program name) 33 Returns: 34 A tuple (opts, payload, extra_args), where `opts' are the options 35 returned by the parser, `payload' is the name of the payload file 36 (mandatory argument) and `extra_args' are any additional command-line 37 arguments. 38 39 """ 40 parser = optparse.OptionParser( 41 usage=('Usage: %prog [OPTION...] PAYLOAD [DST_KERN DST_ROOT ' 42 '[SRC_KERN SRC_ROOT]]'), 43 description=('Applies a Chrome OS update PAYLOAD to SRC_KERN and ' 44 'SRC_ROOT emitting DST_KERN and DST_ROOT, respectively. ' 45 'SRC_KERN and SRC_ROOT are only needed for delta payloads. ' 46 'When no partitions are provided, verifies the payload ' 47 'integrity.'), 48 epilog=('Note: a payload may verify correctly but fail to apply, and ' 49 'vice versa; this is by design and can be thought of as static ' 50 'vs dynamic correctness. A payload that both verifies and ' 51 'applies correctly should be safe for use by the Chrome OS ' 52 'Update Engine. Use --check to verify a payload prior to ' 53 'applying it.')) 54 55 default_key = os.path.join(lib_dir, 56 'update_payload/update-payload-key.pub.pem') 57 58 check_opts = optparse.OptionGroup(parser, 'Payload integrity checking') 59 check_opts.add_option('-c', '--check', action='store_true', default=False, 60 help=('force payload integrity check (e.g. before ' 61 'applying)')) 62 check_opts.add_option('-r', '--report', metavar='FILE', 63 help="dump payload report (`-' for stdout)") 64 check_opts.add_option('-t', '--type', metavar='TYPE', dest='assert_type', 65 help=("assert that payload is either `%s' or `%s'" % 66 (_TYPE_FULL, _TYPE_DELTA))) 67 check_opts.add_option('-z', '--block-size', metavar='NUM', default=0, 68 type='int', 69 help='assert a non-default (4096) payload block size') 70 check_opts.add_option('-u', '--allow-unhashed', action='store_true', 71 default=False, help='allow unhashed operations') 72 check_opts.add_option('-d', '--disabled_tests', metavar='TESTLIST', 73 default=(), 74 help=('comma-separated list of tests to disable; ' 75 'available values: ' + 76 ', '.join(update_payload.CHECKS_TO_DISABLE))) 77 check_opts.add_option('-k', '--key', metavar='FILE', default=default_key, 78 help=('Override standard key used for signature ' 79 'validation')) 80 check_opts.add_option('-m', '--meta-sig', metavar='FILE', 81 help='verify metadata against its signature') 82 check_opts.add_option('-p', '--root-part-size', metavar='NUM', 83 default=_DEFAULT_ROOTFS_PART_SIZE, type='int', 84 help=('override default (%default) rootfs partition ' 85 'size')) 86 check_opts.add_option('-P', '--kern-part-size', metavar='NUM', 87 default=_DEFAULT_KERNEL_PART_SIZE, type='int', 88 help=('override default (%default) kernel partition ' 89 'size')) 90 91 parser.add_option_group(check_opts) 92 93 trace_opts = optparse.OptionGroup(parser, 'Block tracing') 94 trace_opts.add_option('-b', '--root-block', metavar='BLOCK', type='int', 95 help='trace the origin for a rootfs block') 96 trace_opts.add_option('-B', '--kern-block', metavar='BLOCK', type='int', 97 help='trace the origin for a kernel block') 98 trace_opts.add_option('-s', '--skip', metavar='NUM', default='0', type='int', 99 help='skip first NUM occurrences of traced block') 100 parser.add_option_group(trace_opts) 101 102 # Parse command-line arguments. 103 opts, args = parser.parse_args(argv) 104 105 # Validate a value given to --type, if any. 106 if opts.assert_type not in (None, _TYPE_FULL, _TYPE_DELTA): 107 parser.error('invalid argument to --type: %s' % opts.assert_type) 108 109 # Convert and validate --disabled_tests value list, if provided. 110 if opts.disabled_tests: 111 opts.disabled_tests = opts.disabled_tests.split(',') 112 for test in opts.disabled_tests: 113 if test not in update_payload.CHECKS_TO_DISABLE: 114 parser.error('invalid argument to --disabled_tests: %s' % test) 115 116 # Ensure consistent use of block tracing options. 117 do_block_trace = opts.root_block or opts.kern_block 118 if opts.skip and not do_block_trace: 119 parser.error('--skip must be used with either --root-block or --kern-block') 120 121 # There are several options that imply --check. 122 opts.check = (opts.check or opts.report or opts.assert_type or 123 opts.block_size or opts.allow_unhashed or 124 opts.disabled_tests or opts.key or opts.meta_sig or 125 opts.root_part_size != _DEFAULT_ROOTFS_PART_SIZE or 126 opts.kern_part_size != _DEFAULT_KERNEL_PART_SIZE) 127 128 # Check number of arguments, enforce payload type accordingly. 129 if len(args) == 3: 130 if opts.assert_type == _TYPE_DELTA: 131 parser.error('%s payload requires source partition arguments' % 132 _TYPE_DELTA) 133 opts.assert_type = _TYPE_FULL 134 elif len(args) == 5: 135 if opts.assert_type == _TYPE_FULL: 136 parser.error('%s payload does not accept source partition arguments' % 137 _TYPE_FULL) 138 opts.assert_type = _TYPE_DELTA 139 elif len(args) == 1: 140 # Not applying payload; if block tracing not requested either, do an 141 # integrity check. 142 if not do_block_trace: 143 opts.check = True 144 else: 145 parser.error('unexpected number of arguments') 146 147 # By default, look for a metadata-signature file with a name based on the name 148 # of the payload we are checking. We only do it when check is triggered and a 149 # public key provided, so as not to force a metadata signature to fail. 150 if opts.check and opts.key and not opts.meta_sig: 151 default_meta_sig = args[0] + '.metadata-signature' 152 if os.path.isfile(default_meta_sig): 153 opts.meta_sig = default_meta_sig 154 print >> sys.stderr, 'Using default metadata signature', opts.meta_sig 155 156 return opts, args[0], args[1:] 157 158 159def main(argv): 160 # Parse and validate arguments. 161 options, payload_file_name, extra_args = ParseArguments(argv[1:]) 162 163 with open(payload_file_name) as payload_file: 164 payload = update_payload.Payload(payload_file) 165 try: 166 # Initialize payload. 167 payload.Init() 168 169 # Perform payload integrity checks. 170 if options.check: 171 report_file = None 172 do_close_report_file = False 173 try: 174 if options.report: 175 if options.report == '-': 176 report_file = sys.stdout 177 else: 178 report_file = open(options.report, 'w') 179 do_close_report_file = True 180 181 metadata_sig_file = ( 182 open(options.meta_sig) if options.meta_sig else None) 183 payload.Check( 184 pubkey_file_name=options.key, 185 metadata_sig_file=metadata_sig_file, 186 report_out_file=report_file, 187 assert_type=options.assert_type, 188 block_size=int(options.block_size), 189 rootfs_part_size=options.root_part_size, 190 kernel_part_size=options.kern_part_size, 191 allow_unhashed=options.allow_unhashed, 192 disabled_tests=options.disabled_tests) 193 finally: 194 if do_close_report_file: 195 report_file.close() 196 197 # Trace blocks. 198 if options.root_block is not None: 199 payload.TraceBlock(options.root_block, options.skip, sys.stdout, False) 200 if options.kern_block is not None: 201 payload.TraceBlock(options.kern_block, options.skip, sys.stdout, True) 202 203 # Apply payload. 204 if extra_args: 205 if options.assert_type == _TYPE_FULL: 206 payload.Apply(extra_args[0], extra_args[1]) 207 elif options.assert_type == _TYPE_DELTA: 208 payload.Apply(extra_args[0], extra_args[1], 209 src_kernel_part=extra_args[2], 210 src_rootfs_part=extra_args[3]) 211 else: 212 assert False, 'cannot get here' 213 214 except update_payload.PayloadError, e: 215 sys.stderr.write('Error: %s\n' % e) 216 return 1 217 218 return 0 219 220 221if __name__ == '__main__': 222 sys.exit(main(sys.argv)) 223