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
)
87 ###--------------------------------------------------------------------------
90 ## The special variables, to be picked out by `cgiparse'.
91 CGI
.SPECIAL
['%act'] = None
92 CGI
.SPECIAL
['%nonce'] = None
93 CGI
.SPECIAL
['%user'] = None
95 ## We don't want to parse arguments until we've settled on a context; but
96 ## issuing redirects in the early setup phase fails because we don't know
97 ## the script name. So package the setup here.
98 def cgi_setup(ctx
= 'cgi-noauth'):
101 OPTPARSE
.context
= ctx
102 OPTS
, args
= OPTPARSE
.parse_args()
103 if args
: raise U
.ExpectedError
, (500, 'Unexpected arguments to CGI')
104 CONF
.loadconfig(OPTS
.config
)
108 """Examine the CGI request and invoke the appropriate command."""
110 ## Start by picking apart the request.
113 ## We'll be taking items off the trailing path.
114 i
, np
= 0, len(CGI
.PATH
)
116 ## Sometimes, we want to run several actions out of the same form, so the
117 ## subcommand name needs to be in the query string. We use the special
118 ## variable `%act' for this. If it's not set, then we use the first elment
120 act
= CGI
.SPECIAL
['%act']
124 CGI
.redirect(CGI
.action('login'))
129 ## Figure out which context we're meant to be operating in, according to
130 ## the requested action. Unknown actions result in an error here; known
131 ## actions where we don't have enough authorization send the user back to
133 for ctx
in ['cgi-noauth', 'cgi-query', 'cgi']:
135 c
= OPTPARSE
.lookup_subcommand(act
, exactp
= True, context
= ctx
)
136 except U
.ExpectedError
, e
:
137 if e
.code
!= 404: raise
143 ## Parse the command line, and load configuration.
146 ## Check whether we have enough authorization. There's always enough for
148 if ctx
!= 'cgi-noauth':
150 ## The next part of the URL should be the user name, so that caches don't
151 ## cross things over.
152 expuser
= CGI
.SPECIAL
['%user']
154 if i
>= np
: raise U
.ExpectedError
, (404, 'Missing user name')
155 expuser
= CGI
.PATH
[i
]
158 ## If there's no token cookie, then we have to bail.
159 try: token
= CGI
.COOKIE
['chpwd-token']
161 CGI
.redirect(CGI
.action('login', why
= 'NOAUTH'))
164 ## If we only want read-only access, then the cookie is good enough.
165 ## Otherwise we must check that a nonce was supplied, and that it is
167 if ctx
== 'cgi-query':
170 nonce
= CGI
.SPECIAL
['%nonce']
172 CGI
.redirect(CGI
.action('login', why
= 'NONONCE'))
175 ## Verify the token and nonce.
177 CU
.USER
= HA
.check_auth(token
, nonce
)
178 except HA
.AuthenticationFailed
, e
:
179 CGI
.redirect(CGI
.action('login', why
= e
.why
))
181 if CU
.USER
!= expuser
: raise U
.ExpectedError
, (401, 'User mismatch')
182 CGI
.STATE
.kw
['user'] = CU
.USER
184 ## Invoke the subcommand handler.
185 c
.cgi(CGI
.PARAM
, CGI
.PATH
[i
:])
187 ###--------------------------------------------------------------------------
192 """Catch expected errors and report them in the traditional Unix style."""
195 except U
.ExpectedError
, e
:
196 SYS
.stderr
.write('%s: %s\n' %
(OS
.path
.basename(SYS
.argv
[0]), e
.msg
))
197 if 400 <= e
.code
< 500: SYS
.exit(1)
202 if __name__
== '__main__':
204 L
.openlog(OS
.path
.basename(SYS
.argv
[0]), 0, L
.LOG_AUTH
)
206 if 'REQUEST_METHOD' in ENV
:
207 ## This looks like a CGI request. The heavy lifting for authentication
208 ## over HTTP is done in `dispatch_cgi'.
210 with OUT
.redirect_to(CGI
.HTTPOutput()):
211 with U
.Escape() as CGI
.HEADER_DONE
:
212 with CGI
.cgi_errors(cgi_setup
):
215 elif 'USERV_SERVICE' in ENV
:
216 ## This is a Userv request. The caller's user name is helpfully in the
217 ## `USERV_USER' environment variable.
220 OPTS
, args
= OPTPARSE
.parse_args()
221 if not args
or args
[0] != 'userv':
222 raise U
.ExpectedError
, (500, 'missing userv token')
223 CONF
.loadconfig(OPTS
.config
)
224 try: CU
.set_user(ENV
['USERV_USER'])
225 except KeyError: raise ExpectedError
, (500, 'USERV_USER unset')
226 with OUT
.redirect_to(O
.FileOutput()):
227 OPTPARSE
.dispatch('userv', [ENV
['USERV_SERVICE']] + args
[1:])
229 elif 'SSH_ORIGINAL_COMMAND' in ENV
:
230 ## This looks like an SSH request; but we present two different
231 ## interfaces over SSH. We must distinguish them -- carefully: they have
232 ## very different error-reporting conventions.
235 """Extract and parse the client's request from where SSH left it."""
237 OPTS
, args
= OPTPARSE
.parse_args()
238 CONF
.loadconfig(OPTS
.config
)
239 cmd
= SL
.split(ENV
['SSH_ORIGINAL_COMMAND'])
240 if args
: raise U
.ExpectedError
, (500, 'Unexpected arguments via SSH')
243 if 'CHPWD_SSH_USER' in ENV
:
244 ## Setting `CHPWD_SSH_USER' to a user name is the administrator's way
245 ## of telling us that this is a user request, so treat it like Userv.
249 CU
.set_user(ENV
['CHPWD_SSH_USER'])
250 with OUT
.redirect_to(O
.FileOutput()):
251 OPTPARSE
.dispatch('userv', cmd
)
253 elif 'CHPWD_SSH_MASTER' in ENV
:
254 ## Setting `CHPWD_SSH_MASTER' to anything tells us that the client is
255 ## making a remote-service request. We must turn on the protocol
256 ## decoration machinery, but don't need to -- mustn't, indeed -- set up
261 with OUT
.redirect_to(O
.RemoteOutput()):
262 OPTPARSE
.dispatch('remote', map(CGI
.urldecode
, cmd
))
263 except U
.ExpectedError
, e
:
264 print 'ERR', e
.code
, e
.msg
269 ## There's probably some strange botch in the `.ssh/authorized_keys'
270 ## file, but we can't do much about it from here.
273 raise U
.ExpectedError
, (400, "Unabled to determine SSH context")
276 ## Plain old command line, apparently. We default to administration
277 ## commands, but allow any kind, since this is useful for debugging, and
278 ## this isn't a security problem since our caller is just as privileged
282 OPTS
, args
= OPTPARSE
.parse_args()
283 CONF
.loadconfig(OPTS
.config
)
287 CU
.set_user(OPTS
.user
)
288 CGI
.STATE
.kw
['user'] = OPTS
.user
289 if ctx
is None: ctx
= 'userv'
292 if ctx
is None: ctx
= 'admin'
293 with OUT
.redirect_to(O
.FileOutput()):
294 OPTPARSE
.dispatch(ctx
, args
)
296 ###----- That's all, folks --------------------------------------------------