chiark / gitweb /
Use the new mLib macros for discarding uninteresting error codes.
[tripe] / keys / tripe-keys.in
CommitLineData
060ca767 1#! @PYTHON@
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2### -*-python-*-
3###
4### Key management and distribution
5###
6### (c) 2006 Straylight/Edgeware
7###
8
9###----- Licensing notice ---------------------------------------------------
10###
11### This file is part of Trivial IP Encryption (TrIPE).
12###
13### TrIPE is free software; you can redistribute it and/or modify
14### it under the terms of the GNU General Public License as published by
15### the Free Software Foundation; either version 2 of the License, or
16### (at your option) any later version.
17###
18### TrIPE is distributed in the hope that it will be useful,
19### but WITHOUT ANY WARRANTY; without even the implied warranty of
20### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21### GNU General Public License for more details.
22###
23### You should have received a copy of the GNU General Public License
24### along with TrIPE; if not, write to the Free Software Foundation,
25### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26
27###--------------------------------------------------------------------------
28### External dependencies.
060ca767 29
30import catacomb as C
31import os as OS
32import sys as SYS
c55f0b7c 33import re as RX
060ca767 34import getopt as O
c77687d5 35import shutil as SH
c2f28e4b 36import time as T
c77687d5 37import filecmp as FC
060ca767 38from cStringIO import StringIO
39from errno import *
40from stat import *
41
fd42a1e5 42###--------------------------------------------------------------------------
060ca767 43### Useful regular expressions
44
fd42a1e5 45## Match a comment or blank line.
c77687d5 46rx_comment = RX.compile(r'^\s*(#|$)')
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47
48## Match a KEY = VALUE assignment.
c77687d5 49rx_keyval = RX.compile(r'^\s*([-\w]+)(?:\s+(?!=)|\s*=\s*)(|\S|\S.*\S)\s*$')
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50
51## Match a ${KEY} substitution.
c77687d5 52rx_dollarsubst = RX.compile(r'\$\{([-\w]+)\}')
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53
54## Match a @TAG@ substitution.
c77687d5 55rx_atsubst = RX.compile(r'@([-\w]+)@')
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56
57## Match a single non-alphanumeric character.
c77687d5 58rx_nonalpha = RX.compile(r'\W')
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59
60## Match the literal string "<SEQ>".
c77687d5 61rx_seq = RX.compile(r'\<SEQ\>')
060ca767 62
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63## Match a shell metacharacter.
64rx_shmeta = RX.compile('[\\s`!"#$&*()\\[\\];\'|<>?\\\\]')
65
66## Match a character which needs escaping in a shell double-quoted string.
67rx_shquote = RX.compile(r'["`$\\]')
68
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69###--------------------------------------------------------------------------
70### Utility functions.
060ca767 71
fd42a1e5 72## Exceptions.
060ca767 73class SubprocessError (Exception): pass
74class VerifyError (Exception): pass
75
fd42a1e5 76## Program name and identification.
060ca767 77quis = OS.path.basename(SYS.argv[0])
78PACKAGE = "@PACKAGE@"
79VERSION = "@VERSION@"
80
81def moan(msg):
fd42a1e5 82 """Report MSG to standard error."""
060ca767 83 SYS.stderr.write('%s: %s\n' % (quis, msg))
84
85def die(msg, rc = 1):
fd42a1e5 86 """Report MSG to standard error, and exit with code RC."""
060ca767 87 moan(msg)
88 SYS.exit(rc)
89
90def subst(s, rx, map):
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91 """
92 Substitute values into a string.
93
94 Repeatedly match RX (a compiled regular expression) against the string S.
95 For each match, extract group 1, and use it as a key to index the MAP;
96 replace the match by the result. Finally, return the fully-substituted
97 string.
98 """
060ca767 99 out = StringIO()
100 i = 0
101 for m in rx.finditer(s):
102 out.write(s[i:m.start()] + map[m.group(1)])
103 i = m.end()
104 out.write(s[i:])
105 return out.getvalue()
106
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107def shell_quotify(arg):
108 """
109 Quotify ARG to keep the shell happy.
110
111 This isn't actually used for invoking commands, just for presentation
112 purposes; but correctness is still nice.
113 """
114 if not rx_shmeta.search(arg):
115 return arg
116 elif arg.find("'") == -1:
117 return "'%s'" % arg
118 else:
119 return '"%s"' % rx_shquote.sub(lambda m: '\\' + m.group(0), arg)
120
060ca767 121def rmtree(path):
fd42a1e5 122 """Delete the directory tree given by PATH."""
060ca767 123 try:
c77687d5 124 st = OS.lstat(path)
060ca767 125 except OSError, err:
126 if err.errno == ENOENT:
127 return
128 raise
129 if not S_ISDIR(st.st_mode):
130 OS.unlink(path)
131 else:
132 cwd = OS.getcwd()
133 try:
134 OS.chdir(path)
135 for i in OS.listdir('.'):
136 rmtree(i)
137 finally:
138 OS.chdir(cwd)
139 OS.rmdir(path)
140
141def zap(file):
fd42a1e5 142 """Delete the named FILE if it exists; otherwise do nothing."""
060ca767 143 try:
144 OS.unlink(file)
145 except OSError, err:
146 if err.errno == ENOENT: return
147 raise
148
149def run(args):
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150 """
151 Run a subprocess whose arguments are given by the string ARGS.
152
153 The ARGS are split at word boundaries, and then subjected to configuration
154 variable substitution (see conf_subst). Individual argument elements
155 beginning with `!' are split again into multiple arguments at word
156 boundaries.
157 """
060ca767 158 args = map(conf_subst, args.split())
159 nargs = []
160 for a in args:
161 if len(a) > 0 and a[0] != '!':
162 nargs += [a]
163 else:
164 nargs += a[1:].split()
165 args = nargs
6005ef9b 166 print '+ %s' % ' '.join([shell_quotify(arg) for arg in args])
8cae2567 167 SYS.stdout.flush()
060ca767 168 rc = OS.spawnvp(OS.P_WAIT, args[0], args)
169 if rc != 0:
170 raise SubprocessError, rc
171
172def hexhyphens(bytes):
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173 """
174 Convert a byte string BYTES into hex, with hyphens at each 4-byte boundary.
175 """
060ca767 176 out = StringIO()
177 for i in xrange(0, len(bytes)):
178 if i > 0 and i % 4 == 0: out.write('-')
179 out.write('%02x' % ord(bytes[i]))
180 return out.getvalue()
181
182def fingerprint(kf, ktag):
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183 """
184 Compute the fingerprint of a key, using the user's selected hash.
185
186 KF is the name of a keyfile; KTAG is the tag of the key.
187 """
060ca767 188 h = C.gchashes[conf['fingerprint-hash']]()
189 k = C.KeyFile(kf)[ktag].fingerprint(h, '-secret')
190 return h.done()
191
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192###--------------------------------------------------------------------------
193### The configuration file.
060ca767 194
fd42a1e5 195## Exceptions.
060ca767 196class ConfigFileError (Exception): pass
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197
198## The configuration dictionary.
060ca767 199conf = {}
200
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201def conf_subst(s):
202 """
203 Apply configuration substitutions to S.
204
205 That is, for each ${KEY} in S, replace it with the current value of the
206 configuration variable KEY.
207 """
208 return subst(s, rx_dollarsubst, conf)
060ca767 209
060ca767 210def conf_read(f):
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211 """
212 Read the file F and insert assignments into the configuration dictionary.
213 """
060ca767 214 lno = 0
215 for line in file(f):
216 lno += 1
c77687d5 217 if rx_comment.match(line): continue
060ca767 218 if line[-1] == '\n': line = line[:-1]
c77687d5 219 match = rx_keyval.match(line)
060ca767 220 if not match:
221 raise ConfigFileError, "%s:%d: bad line `%s'" % (f, lno, line)
222 k, v = match.groups()
223 conf[k] = conf_subst(v)
224
060ca767 225def conf_defaults():
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226 """
227 Apply defaults to the configuration dictionary.
228
229 Fill in all the interesting configuration variables based on the existing
230 contents, as described in the manual.
231 """
c77687d5 232 for k, v in [('repos-base', 'tripe-keys.tar.gz'),
233 ('sig-base', 'tripe-keys.sig-<SEQ>'),
234 ('repos-url', '${base-url}${repos-base}'),
235 ('sig-url', '${base-url}${sig-base}'),
236 ('sig-file', '${base-dir}${sig-base}'),
237 ('repos-file', '${base-dir}${repos-base}'),
060ca767 238 ('conf-file', '${base-dir}tripe-keys.conf'),
b14ccd2f 239 ('upload-hook', ': run upload hook'),
060ca767 240 ('kx', 'dh'),
ca3aaaeb 241 ('kx-param', lambda: {'dh': '-LS -b3072 -B256',
060ca767 242 'ec': '-Cnist-p256'}[conf['kx']]),
243 ('kx-expire', 'now + 1 year'),
c2f28e4b 244 ('kx-warn-days', '28'),
ca3aaaeb 245 ('cipher', 'rijndael-cbc'),
060ca767 246 ('hash', 'sha256'),
7858dfa0 247 ('master-keygen-flags', '-l'),
060ca767 248 ('mgf', '${hash}-mgf'),
249 ('mac', lambda: '%s-hmac/%d' %
250 (conf['hash'],
251 C.gchashes[conf['hash']].hashsz * 4)),
252 ('sig', lambda: {'dh': 'dsa', 'ec': 'ecdsa'}[conf['kx']]),
253 ('sig-fresh', 'always'),
254 ('sig-genalg', lambda: {'kcdsa': 'dh',
255 'dsa': 'dsa',
256 'rsapkcs1': 'rsa',
257 'rsapss': 'rsa',
258 'ecdsa': 'ec',
259 'eckcdsa': 'ec'}[conf['sig']]),
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260 ('sig-param', lambda: {'dh': '-LS -b3072 -B256',
261 'dsa': '-b3072 -B256',
060ca767 262 'ec': '-Cnist-p256',
ca3aaaeb 263 'rsa': '-b3072'}[conf['sig-genalg']]),
060ca767 264 ('sig-hash', '${hash}'),
265 ('sig-expire', 'forever'),
266 ('fingerprint-hash', '${hash}')]:
267 try:
268 if k in conf: continue
269 if type(v) == str:
270 conf[k] = conf_subst(v)
271 else:
272 conf[k] = v()
273 except KeyError, exc:
274 if len(exc.args) == 0: raise
275 conf[k] = '<missing-var %s>' % exc.args[0]
276
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277###--------------------------------------------------------------------------
278### Key-management utilities.
279
280def master_keys():
281 """
282 Iterate over the master keys.
283 """
284 if not OS.path.exists('master'):
285 return
286 for k in C.KeyFile('master').itervalues():
287 if (k.type != 'tripe-keys-master' or
288 k.expiredp or
289 not k.tag.startswith('master-')):
290 continue #??
291 yield k
292
293def master_sequence(k):
294 """
295 Return the sequence number of the given master key as an integer.
296
297 No checking is done that K is really a master key.
298 """
299 return int(k.tag[7:])
300
301def max_master_sequence():
302 """
303 Find the master key with the highest sequence number and return this
304 sequence number.
305 """
306 seq = -1
307 for k in master_keys():
308 q = master_sequence(k)
309 if q > seq: seq = q
310 return seq
311
312def seqsubst(x, q):
313 """
314 Return the value of the configuration variable X, with <SEQ> replaced by
315 the value Q.
316 """
317 return rx_seq.sub(str(q), conf[x])
318
319###--------------------------------------------------------------------------
320### Commands: help [COMMAND...]
060ca767 321
322def version(fp = SYS.stdout):
323 fp.write('%s, %s version %s\n' % (quis, PACKAGE, VERSION))
324
325def usage(fp):
326 fp.write('Usage: %s SUBCOMMAND [ARGS...]\n' % quis)
327
328def cmd_help(args):
329 if len(args) == 0:
330 version(SYS.stdout)
331 print
332 usage(SYS.stdout)
333 print """
334Key management utility for TrIPE.
335
336Options supported:
337
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338-h, --help Show this help message.
339-v, --version Show the version number.
340-u, --usage Show pointlessly short usage string.
060ca767 341
342Subcommands available:
343"""
344 args = commands.keys()
345 args.sort()
346 for c in args:
347 func, min, max, help = commands[c]
348 print '%s %s' % (c, help)
349
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350###--------------------------------------------------------------------------
351### Commands: newmaster
c77687d5 352
353def cmd_newmaster(args):
354 seq = max_master_sequence() + 1
060ca767 355 run('''key -kmaster add
356 -a${sig-genalg} !${sig-param}
7858dfa0 357 -e${sig-expire} !${master-keygen-flags} -tmaster-%d tripe-keys-master
c77687d5 358 sig=${sig} hash=${sig-hash}''' % seq)
359 run('key -kmaster extract -f-secret repos/master.pub')
060ca767 360
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361###--------------------------------------------------------------------------
362### Commands: setup
363
c77687d5 364def cmd_setup(args):
365 OS.mkdir('repos')
060ca767 366 run('''key -krepos/param add
367 -a${kx}-param !${kx-param}
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368 -eforever -tparam tripe-param
369 kx-group=${kx} cipher=${cipher} hash=${hash} mac=${mac} mgf=${mgf}''')
c77687d5 370 cmd_newmaster(args)
060ca767 371
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372###--------------------------------------------------------------------------
373### Commands: upload
374
060ca767 375def cmd_upload(args):
376
377 ## Sanitize the repository directory
378 umask = OS.umask(0); OS.umask(umask)
379 mode = 0666 & ~umask
380 for f in OS.listdir('repos'):
381 ff = OS.path.join('repos', f)
c77687d5 382 if (f.startswith('master') or f.startswith('peer-')) \
383 and f.endswith('.old'):
060ca767 384 OS.unlink(ff)
385 continue
c77687d5 386 OS.chmod(ff, mode)
387
388 rmtree('tmp')
389 OS.mkdir('tmp')
390 OS.symlink('../repos', 'tmp/repos')
391 cwd = OS.getcwd()
392 try:
393
394 ## Build the configuration file
395 seq = max_master_sequence()
396 v = {'MASTER-SEQUENCE': str(seq),
397 'HK-MASTER': hexhyphens(fingerprint('repos/master.pub',
398 'master-%d' % seq))}
399 fin = file('tripe-keys.master')
400 fout = file('tmp/tripe-keys.conf', 'w')
401 for line in fin:
402 fout.write(subst(line, rx_atsubst, v))
403 fin.close(); fout.close()
404 SH.copyfile('tmp/tripe-keys.conf', conf_subst('${conf-file}.new'))
405 commit = [conf['repos-file'], conf['conf-file']]
406
407 ## Make and sign the repository archive
408 OS.chdir('tmp')
409 run('tar chozf ${repos-file}.new .')
410 OS.chdir(cwd)
411 for k in master_keys():
412 seq = master_sequence(k)
413 sigfile = seqsubst('sig-file', seq)
414 run('''catsign -kmaster sign -abdC -kmaster-%d
415 -o%s.new ${repos-file}.new''' % (seq, sigfile))
416 commit.append(sigfile)
417
418 ## Commit the changes
419 for base in commit:
420 new = '%s.new' % base
421 OS.rename(new, base)
422 finally:
423 OS.chdir(cwd)
e04c2d50 424 rmtree('tmp')
b14ccd2f 425 run('sh -c ${upload-hook}')
060ca767 426
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427###--------------------------------------------------------------------------
428### Commands: rebuild
429
430def cmd_rebuild(args):
431 zap('keyring.pub')
432 for i in OS.listdir('repos'):
433 if i.startswith('peer-') and i.endswith('.pub'):
434 run('key -kkeyring.pub merge %s' % OS.path.join('repos', i))
435
436###--------------------------------------------------------------------------
437### Commands: update
438
060ca767 439def cmd_update(args):
440 cwd = OS.getcwd()
441 rmtree('tmp')
442 try:
443
444 ## Fetch a new distribution
445 OS.mkdir('tmp')
446 OS.chdir('tmp')
c77687d5 447 seq = int(conf['master-sequence'])
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448 run('curl -s -o tripe-keys.tar.gz ${repos-url}')
449 run('curl -s -o tripe-keys.sig %s' % seqsubst('sig-url', seq))
060ca767 450 run('tar xfz tripe-keys.tar.gz')
451
452 ## Verify the signature
c77687d5 453 want = C.bytes(rx_nonalpha.sub('', conf['hk-master']))
454 got = fingerprint('repos/master.pub', 'master-%d' % seq)
060ca767 455 if want != got: raise VerifyError
c77687d5 456 run('''catsign -krepos/master.pub verify -avC -kmaster-%d
457 -t${sig-fresh} tripe-keys.sig tripe-keys.tar.gz''' % seq)
060ca767 458
459 ## OK: update our copy
460 OS.chdir(cwd)
461 if OS.path.exists('repos'): OS.rename('repos', 'repos.old')
462 OS.rename('tmp/repos', 'repos')
c77687d5 463 if not FC.cmp('tmp/tripe-keys.conf', 'tripe-keys.conf'):
464 moan('configuration file changed: recommend running another update')
465 OS.rename('tmp/tripe-keys.conf', 'tripe-keys.conf')
060ca767 466 rmtree('repos.old')
467
468 finally:
469 OS.chdir(cwd)
470 rmtree('tmp')
471 cmd_rebuild(args)
472
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473###--------------------------------------------------------------------------
474### Commands: generate TAG
060ca767 475
476def cmd_generate(args):
477 tag, = args
478 keyring_pub = 'peer-%s.pub' % tag
479 zap('keyring'); zap(keyring_pub)
480 run('key -kkeyring merge repos/param')
fc5f4823 481 run('key -kkeyring add -a${kx} -pparam -e${kx-expire} -t%s tripe' %
c77687d5 482 tag)
ca6eb20c 483 run('key -kkeyring extract -f-secret %s %s' % (keyring_pub, tag))
060ca767 484
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485###--------------------------------------------------------------------------
486### Commands: clean
487
060ca767 488def cmd_clean(args):
489 rmtree('repos')
490 rmtree('tmp')
c77687d5 491 for i in OS.listdir('.'):
492 r = i
493 if r.endswith('.old'): r = r[:-4]
494 if (r == 'master' or r == 'param' or
495 r == 'keyring' or r == 'keyring.pub' or r.startswith('peer-')):
496 zap(i)
060ca767 497
fd42a1e5 498###--------------------------------------------------------------------------
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499### Commands: check
500
501def cmd_check(args):
502 now = T.time()
503 thresh = int(conf['kx-warn-days']) * 86400
504 for krf in ['master', 'keyring.pub']:
505 if not OS.path.exists(krf): continue
506 kr = C.KeyFile(krf)
507 for k in kr.itervalues():
508 if k.exptime == C.KEXP_FOREVER: continue
509 elif k.exptime == C.KEXP_EXPIRE: left = -1
510 else: left = k.exptime - now
511 if left < 0:
512 print "key `%s' HAS EXPIRED" % k.tag
513 elif left < thresh:
514 if left >= 86400: n, u, uu = left // 86400, 'day', 'days'
515 else: n, u, uu = left // 3600, 'hour', 'hours'
516 print "key `%s' EXPIRES in %d %s" % (k.tag, n, n == 1 and u or uu)
517
518###--------------------------------------------------------------------------
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519### Commands: mtu
520
521def cmd_mtu(args):
522 mtu, = (lambda mtu = '1500': (mtu,))(*args)
523 mtu = int(mtu)
524
525 blksz = C.gcciphers[conf['cipher']].blksz
526
527 index = conf['mac'].find('/')
528 if index == -1:
529 tagsz = C.gcmacs[conf['mac']].tagsz
530 else:
531 tagsz = int(conf['mac'][index + 1:])/8
532
533 mtu -= 20 # Minimum IP header
534 mtu -= 8 # UDP header
535 mtu -= 1 # TrIPE packet type octet
536 mtu -= tagsz # MAC tag
537 mtu -= 4 # Sequence number
538 mtu -= blksz # Initialization vector
539
540 print mtu
541
542###--------------------------------------------------------------------------
fd42a1e5 543### Main driver.
060ca767 544
fd42a1e5 545## Exceptions.
060ca767 546class UsageError (Exception): pass
e04c2d50 547
060ca767 548commands = {'help': (cmd_help, 0, 1, ''),
c77687d5 549 'newmaster': (cmd_newmaster, 0, 0, ''),
060ca767 550 'setup': (cmd_setup, 0, 0, ''),
551 'upload': (cmd_upload, 0, 0, ''),
552 'update': (cmd_update, 0, 0, ''),
553 'clean': (cmd_clean, 0, 0, ''),
65faf8df 554 'mtu': (cmd_mtu, 0, 1, '[PATH-MTU]'),
c2f28e4b 555 'check': (cmd_check, 0, 0, ''),
060ca767 556 'generate': (cmd_generate, 1, 1, 'TAG'),
557 'rebuild': (cmd_rebuild, 0, 0, '')}
558
559def init():
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560 """
561 Load the appropriate configuration file and set up the configuration
562 dictionary.
563 """
060ca767 564 for f in ['tripe-keys.master', 'tripe-keys.conf']:
565 if OS.path.exists(f):
566 conf_read(f)
567 break
568 conf_defaults()
fd42a1e5 569
060ca767 570def main(argv):
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571 """
572 Main program: parse options and dispatch to appropriate command handler.
573 """
060ca767 574 try:
575 opts, args = O.getopt(argv[1:], 'hvu',
576 ['help', 'version', 'usage'])
577 except O.GetoptError, exc:
578 moan(exc)
579 usage(SYS.stderr)
580 SYS.exit(1)
581 for o, v in opts:
582 if o in ('-h', '--help'):
583 cmd_help([])
584 SYS.exit(0)
585 elif o in ('-v', '--version'):
586 version(SYS.stdout)
587 SYS.exit(0)
588 elif o in ('-u', '--usage'):
589 usage(SYS.stdout)
590 SYS.exit(0)
591 if len(argv) < 2:
592 cmd_help([])
593 else:
594 c = argv[1]
595 func, min, max, help = commands[c]
596 args = argv[2:]
597 if len(args) < min or (max > 0 and len(args) > max):
598 raise UsageError, (c, help)
599 func(args)
600
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601###----- That's all, folks --------------------------------------------------
602
603if __name__ == '__main__':
604 init()
605 main(SYS.argv)