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
34 from auto
import HOME
, VERSION
37 import config
as CONF
; CFG
= CONF
.CFG
40 import output
as O
; OUT
= O
.OUT
42 import subcommand
as SC
45 for i
in ['admin', 'cgi', 'remote', 'user']:
46 __import__('cmd-' + i
)
48 ###--------------------------------------------------------------------------
49 ### Parsing command-line options.
51 ## Command-line options parser.
52 OPTPARSE
= SC
.SubcommandOptionParser(
53 usage
= '%prog SUBCOMMAND [ARGS ...]',
54 version
= '%%prog, verion %s' % VERSION
,
55 contexts
= ['admin', 'userv', 'remote', 'cgi', 'cgi-query', 'cgi-noauth'],
56 commands
= SC
.COMMANDS
,
58 Manage all of those annoying passwords.
60 This is free software, and you can redistribute it and/or modify it
61 under the terms of the GNU Affero General Public License
62 <http://www.gnu.org/licenses/agpl-3.0.html>. For a `.tar.gz' file
63 of the source code, use the `source' command.
68 ## Set up the global options.
69 for short
, long, props
in [
71 'metavar': 'CONTEXT', 'dest': 'context', 'default': None,
72 'help': 'run commands with the given CONTEXT' }),
73 ('-f', '--config-file', {
74 'metavar': 'FILE', 'dest': 'config',
75 'default': ENV
.get('CHPWD_CONFIG',
76 OS
.path
.join(HOME
, 'chpwd.conf')),
77 'help': 'read configuration from FILE.' }),
79 'dest': 'sslp', 'action': 'store_true',
80 'help': 'pretend CGI connection is carried over SSL/TLS' }),
82 'metavar': 'USER', 'dest': 'user', 'default': None,
83 'help': "impersonate USER, and default context to `userv'." })]:
84 OPTPARSE
.add_option(short
, long, **props
)
86 ###--------------------------------------------------------------------------
89 ## The special variables, to be picked out by `cgiparse'.
90 CGI
.SPECIAL
['%act'] = None
91 CGI
.SPECIAL
['%nonce'] = None
92 CGI
.SPECIAL
['%user'] = None
94 ## We don't want to parse arguments until we've settled on a context; but
95 ## issuing redirects in the early setup phase fails because we don't know
96 ## the script name. So package the setup here.
97 def cgi_setup(ctx
= 'cgi-noauth'):
100 OPTPARSE
.context
= ctx
101 OPTS
, args
= OPTPARSE
.parse_args()
102 if args
: raise U
.ExpectedError
, (500, 'Unexpected arguments to CGI')
103 CONF
.loadconfig(OPTS
.config
)
107 """Examine the CGI request and invoke the appropriate command."""
109 ## Start by picking apart the request.
112 ## We'll be taking items off the trailing path.
113 i
, np
= 0, len(CGI
.PATH
)
115 ## Sometimes, we want to run several actions out of the same form, so the
116 ## subcommand name needs to be in the query string. We use the special
117 ## variable `%act' for this. If it's not set, then we use the first elment
119 act
= CGI
.SPECIAL
['%act']
123 CGI
.redirect(CGI
.action('login'))
128 ## Figure out which context we're meant to be operating in, according to
129 ## the requested action. Unknown actions result in an error here; known
130 ## actions where we don't have enough authorization send the user back to
132 for ctx
in ['cgi-noauth', 'cgi-query', 'cgi']:
134 c
= OPTPARSE
.lookup_subcommand(act
, exactp
= True, context
= ctx
)
135 except U
.ExpectedError
, e
:
136 if e
.code
!= 404: raise
142 ## Parse the command line, and load configuration.
145 ## Check whether we have enough authorization. There's always enough for
147 if ctx
!= 'cgi-noauth':
149 ## The next part of the URL should be the user name, so that caches don't
150 ## cross things over.
151 expuser
= CGI
.SPECIAL
['%user']
153 if i
>= np
: raise U
.ExpectedError
, (404, 'Missing user name')
154 expuser
= CGI
.PATH
[i
]
157 ## If there's no token cookie, then we have to bail.
158 try: token
= CGI
.COOKIE
['chpwd-token']
160 CGI
.redirect(CGI
.action('login', why
= 'NOAUTH'))
163 ## If we only want read-only access, then the cookie is good enough.
164 ## Otherwise we must check that a nonce was supplied, and that it is
166 if ctx
== 'cgi-query':
169 nonce
= CGI
.SPECIAL
['%nonce']
171 CGI
.redirect(CGI
.action('login', why
= 'NONONCE'))
174 ## Verify the token and nonce.
176 CU
.USER
= HA
.check_auth(token
, nonce
)
177 except HA
.AuthenticationFailed
, e
:
178 CGI
.redirect(CGI
.action('login', why
= e
.why
))
180 if CU
.USER
!= expuser
: raise U
.ExpectedError
, (401, 'User mismatch')
181 CGI
.STATE
.kw
['user'] = CU
.USER
183 ## Invoke the subcommand handler.
184 c
.cgi(CGI
.PARAM
, CGI
.PATH
[i
:])
186 ###--------------------------------------------------------------------------
191 """Catch expected errors and report them in the traditional Unix style."""
194 except U
.ExpectedError
, e
:
195 SYS
.stderr
.write('%s: %s\n' %
(OS
.path
.basename(SYS
.argv
[0]), e
.msg
))
196 if 400 <= e
.code
< 500: SYS
.exit(1)
201 if __name__
== '__main__':
203 if 'REQUEST_METHOD' in ENV
:
204 ## This looks like a CGI request. The heavy lifting for authentication
205 ## over HTTP is done in `dispatch_cgi'.
207 with OUT
.redirect_to(CGI
.HTTPOutput()):
208 with CGI
.cgi_errors(cgi_setup
): dispatch_cgi()
210 elif 'USERV_SERVICE' in ENV
:
211 ## This is a Userv request. The caller's user name is helpfully in the
212 ## `USERV_USER' environment variable.
215 OPTS
, args
= OPTPARSE
.parse_args()
216 CONF
.loadconfig(OPTS
.config
)
217 try: CU
.set_user(ENV
['USERV_USER'])
218 except KeyError: raise ExpectedError
, (500, 'USERV_USER unset')
219 with OUT
.redirect_to(O
.FileOutput()):
220 OPTPARSE
.dispatch('userv', [ENV
['USERV_SERVICE']] + args
)
222 elif 'SSH_ORIGINAL_COMMAND' in ENV
:
223 ## This looks like an SSH request; but we present two different
224 ## interfaces over SSH. We must distinguish them -- carefully: they have
225 ## very different error-reporting conventions.
228 """Extract and parse the client's request from where SSH left it."""
230 OPTS
, args
= OPTPARSE
.parse_args()
231 CONF
.loadconfig(OPTS
.config
)
232 cmd
= SL
.split(ENV
['SSH_ORIGINAL_COMMAND'])
233 if args
: raise U
.ExpectedError
, (500, 'Unexpected arguments via SSH')
236 if 'CHPWD_SSH_USER' in ENV
:
237 ## Setting `CHPWD_SSH_USER' to a user name is the administrator's way
238 ## of telling us that this is a user request, so treat it like Userv.
242 CU
.set_user(ENV
['CHPWD_SSH_USER'])
243 S
.SERVICES
['master'].find(CU
.USER
)
244 with OUT
.redirect_to(O
.FileOutput()):
245 OPTPARSE
.dispatch('userv', cmd
)
247 elif 'CHPWD_SSH_MASTER' in ENV
:
248 ## Setting `CHPWD_SSH_MASTER' to anything tells us that the client is
249 ## making a remote-service request. We must turn on the protocol
250 ## decoration machinery, but don't need to -- mustn't, indeed -- set up
255 with OUT
.redirect_to(O
.RemoteOutput()):
256 OPTPARSE
.dispatch('remote', map(CGI
.urldecode
, cmd
))
257 except U
.ExpectedError
, e
:
258 print 'ERR', e
.code
, e
.msg
263 ## There's probably some strange botch in the `.ssh/authorized_keys'
264 ## file, but we can't do much about it from here.
267 raise U
.ExpectedError
, (400, "Unabled to determine SSH context")
270 ## Plain old command line, apparently. We default to administration
271 ## commands, but allow any kind, since this is useful for debugging, and
272 ## this isn't a security problem since our caller is just as privileged
276 OPTS
, args
= OPTPARSE
.parse_args()
277 CONF
.loadconfig(OPTS
.config
)
281 CU
.set_user(OPTS
.user
)
282 CGI
.STATE
.kw
['user'] = OPTS
.user
283 if ctx
is None: ctx
= 'userv'
286 if ctx
is None: ctx
= 'admin'
287 with OUT
.redirect_to(O
.FileOutput()):
288 OPTPARSE
.dispatch(ctx
, args
)
290 ###----- That's all, folks --------------------------------------------------