3 ### Password management
5 ### (c) 2012 Mark Wooding
8 ###----- Licensing notice ---------------------------------------------------
10 ### This file is part of Chopwood: a password-changing service.
12 ### Chopwood is free software; you can redistribute it and/or modify
13 ### it under the terms of the GNU Affero General Public License as
14 ### published by the Free Software Foundation; either version 3 of the
15 ### License, or (at your option) any later version.
17 ### Chopwood is distributed in the hope that it will be useful,
18 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ### GNU Affero General Public License for more details.
22 ### You should have received a copy of the GNU Affero General Public
23 ### License along with Chopwood; if not, see
24 ### <http://www.gnu.org/licenses/>.
26 from __future__ import with_statement
28 import contextlib as CTX
30 import os as OS; ENV = OS.environ
35 from auto import HOME, VERSION
38 import config as CONF; CFG = CONF.CFG
41 import output as O; OUT = O.OUT
43 import subcommand as SC
46 for i in ['admin', 'cgi', 'remote', 'user']:
47 __import__('cmd-' + i)
49 ###--------------------------------------------------------------------------
50 ### Parsing command-line options.
52 ## Command-line options parser.
53 OPTPARSE = SC.SubcommandOptionParser(
54 usage = '%prog SUBCOMMAND [ARGS ...]',
55 version = '%%prog, verion %s' % VERSION,
56 contexts = ['admin', 'userv', 'remote', 'cgi', 'cgi-query', 'cgi-noauth'],
57 commands = SC.COMMANDS,
59 Manage all of those annoying passwords.
61 This is free software, and you can redistribute it and/or modify it
62 under the terms of the GNU Affero General Public License
63 <http://www.gnu.org/licenses/agpl-3.0.html>. For a `.tar.gz' file
64 of the source code, use the `source' command.
69 ## Set up the global options.
70 for short, long, props in [
72 'metavar': 'CONTEXT', 'dest': 'context', 'default': None,
73 'help': 'run commands with the given CONTEXT' }),
74 ('-f', '--config-file', {
75 'metavar': 'FILE', 'dest': 'config',
76 'default': ENV.get('CHPWD_CONFIG',
77 OS.path.join(HOME, 'chpwd.conf')),
78 'help': 'read configuration from FILE.' }),
80 'dest': 'sslp', 'action': 'store_true',
81 'help': 'pretend CGI connection is carried over SSL/TLS' }),
83 'metavar': 'USER', 'dest': 'user', 'default': None,
84 'help': "impersonate USER, and default context to `userv'." })]:
85 OPTPARSE.add_option(short, long, **props)
89 Parse the main command-line options, returning the positional arguments.
92 OPTS, args = OPTPARSE.parse_args()
93 OPTPARSE.show_global_opts = False
94 ## It's tempting to load the configuration here. Don't do that. Some
95 ## contexts will want to check that the command line was handled properly
96 ## upstream before believing it for anything, such as executing arbitrary
100 ###--------------------------------------------------------------------------
103 ## The special variables, to be picked out by `cgiparse'.
104 CGI.SPECIAL['%act'] = None
105 CGI.SPECIAL['%nonce'] = None
106 CGI.SPECIAL['%user'] = None
108 ## We don't want to parse arguments until we've settled on a context; but
109 ## issuing redirects in the early setup phase fails because we don't know
110 ## the script name. So package the setup here.
111 def cgi_setup(ctx = 'cgi-noauth'):
113 OPTPARSE.context = ctx
114 args = parse_options()
115 if args: raise U.ExpectedError, (500, 'Unexpected arguments to CGI')
116 CONF.loadconfig(OPTS.config)
120 """Examine the CGI request and invoke the appropriate command."""
122 ## Start by picking apart the request.
125 ## We'll be taking items off the trailing path.
126 i, np = 0, len(CGI.PATH)
128 ## Sometimes, we want to run several actions out of the same form, so the
129 ## subcommand name needs to be in the query string. We use the special
130 ## variable `%act' for this. If it's not set, then we use the first elment
132 act = CGI.SPECIAL['%act']
136 CGI.redirect(CGI.action('login'))
141 ## Figure out which context we're meant to be operating in, according to
142 ## the requested action. Unknown actions result in an error here; known
143 ## actions where we don't have enough authorization send the user back to
145 for ctx in ['cgi-noauth', 'cgi-query', 'cgi']:
147 c = OPTPARSE.lookup_subcommand(act, exactp = True, context = ctx)
148 except U.ExpectedError, e:
149 if e.code != 404: raise
155 ## Parse the command line, and load configuration.
158 ## Check whether we have enough authorization. There's always enough for
160 if ctx != 'cgi-noauth':
162 ## The next part of the URL should be the user name, so that caches don't
163 ## cross things over.
164 expuser = CGI.SPECIAL['%user']
166 if i >= np: raise U.ExpectedError, (404, 'Missing user name')
167 expuser = CGI.PATH[i]
170 ## If there's no token cookie, then we have to bail.
171 try: token = CGI.COOKIE['chpwd-token']
173 CGI.redirect(CGI.action('login', why = 'NOAUTH'))
176 ## If we only want read-only access, then the cookie is good enough.
177 ## Otherwise we must check that a nonce was supplied, and that it is
179 if ctx == 'cgi-query':
182 nonce = CGI.SPECIAL['%nonce']
184 CGI.redirect(CGI.action('login', why = 'NONONCE'))
187 ## Verify the token and nonce.
189 CU.USER = HA.check_auth(token, nonce)
190 except HA.AuthenticationFailed, e:
191 CGI.redirect(CGI.action('login', why = e.why))
193 if CU.USER != expuser: raise U.ExpectedError, (401, 'User mismatch')
194 CGI.STATE.kw['user'] = CU.USER
196 ## Invoke the subcommand handler.
197 c.cgi(CGI.PARAM, CGI.PATH[i:])
199 ###--------------------------------------------------------------------------
204 """Catch expected errors and report them in the traditional Unix style."""
207 except U.ExpectedError, e:
208 SYS.stderr.write('%s: %s\n' % (OS.path.basename(SYS.argv[0]), e.msg))
209 if 400 <= e.code < 500: SYS.exit(1)
214 if __name__ == '__main__':
216 L.openlog(OS.path.basename(SYS.argv[0]), 0, L.LOG_AUTH)
218 if 'REQUEST_METHOD' in ENV:
219 ## This looks like a CGI request. The heavy lifting for authentication
220 ## over HTTP is done in `dispatch_cgi'.
222 with OUT.redirect_to(CGI.HTTPOutput()):
223 with U.Escape() as CGI.HEADER_DONE:
224 with CGI.cgi_errors(cgi_setup):
227 elif 'USERV_SERVICE' in ENV:
228 ## This is a Userv request. The caller's user name is helpfully in the
229 ## `USERV_USER' environment variable.
232 with OUT.redirect_to(O.FileOutput()):
233 args = parse_options()
234 if not args or args[0] != 'userv':
235 raise U.ExpectedError, (500, 'missing userv token')
236 CONF.loadconfig(OPTS.config)
237 try: CU.set_user(ENV['USERV_USER'])
238 except KeyError: raise ExpectedError, (500, 'USERV_USER unset')
239 OPTPARSE.dispatch('userv', [ENV['USERV_SERVICE']] + args[1:])
241 elif 'SSH_ORIGINAL_COMMAND' in ENV:
242 ## This looks like an SSH request; but we present two different
243 ## interfaces over SSH. We must distinguish them -- carefully: they have
244 ## very different error-reporting conventions.
247 """Extract and parse the client's request from where SSH left it."""
248 args = parse_options()
249 CONF.loadconfig(OPTS.config)
250 cmd = SL.split(ENV['SSH_ORIGINAL_COMMAND'])
251 if args: raise U.ExpectedError, (500, 'Unexpected arguments via SSH')
254 if 'CHPWD_SSH_USER' in ENV:
255 ## Setting `CHPWD_SSH_USER' to a user name is the administrator's way
256 ## of telling us that this is a user request, so treat it like Userv.
259 with OUT.redirect_to(O.FileOutput()):
261 CU.set_user(ENV['CHPWD_SSH_USER'])
262 OPTPARSE.dispatch('userv', cmd)
264 elif 'CHPWD_SSH_MASTER' in ENV:
265 ## Setting `CHPWD_SSH_MASTER' to anything tells us that the client is
266 ## making a remote-service request. We must turn on the protocol
267 ## decoration machinery, but don't need to -- mustn't, indeed -- set up
271 with OUT.redirect_to(O.RemoteOutput()):
273 OPTPARSE.dispatch('remote', map(CGI.urldecode, cmd))
274 except U.ExpectedError, e:
275 print 'ERR', e.code, e.msg
280 ## There's probably some strange botch in the `.ssh/authorized_keys'
281 ## file, but we can't do much about it from here.
284 raise U.ExpectedError, (400, "Unabled to determine SSH context")
287 ## Plain old command line, apparently. We default to administration
288 ## commands, but allow any kind, since this is useful for debugging, and
289 ## this isn't a security problem since our caller is just as privileged
293 with OUT.redirect_to(O.FileOutput()):
294 args = parse_options()
295 CONF.loadconfig(OPTS.config)
299 CU.set_user(OPTS.user)
300 CGI.STATE.kw['user'] = OPTS.user
301 if ctx is None: ctx = 'userv'
306 OPTPARSE.show_global_opts = True
307 OPTPARSE.dispatch(ctx, args)
309 ###----- That's all, folks --------------------------------------------------