comparison lisp/w3/urlauth.el @ 80:1ce6082ce73f r20-0b90

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date Mon, 13 Aug 2007 09:06:37 +0200
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79:5b0a5bbffab6 80:1ce6082ce73f
1 ;;; urlauth.el --- Uniform Resource Locator authorization modules
2 ;; Author: wmperry
3 ;; Created: 1996/10/09 19:00:59
4 ;; Version: 1.2
5 ;; Keywords: comm, data, processes, hypermedia
6
7 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
8 ;;; Copyright (c) 1993-1996 by William M. Perry (wmperry@cs.indiana.edu)
9 ;;; Copyright (c) 1996 Free Software Foundation, Inc.
10 ;;;
11 ;;; This file is not part of GNU Emacs, but the same permissions apply.
12 ;;;
13 ;;; GNU Emacs 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, or (at your option)
16 ;;; any later version.
17 ;;;
18 ;;; GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to the
25 ;;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
26 ;;; Boston, MA 02111-1307, USA.
27 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
28
29 (require 'url-vars)
30 (require 'url-parse)
31 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
32 ;;; Basic authorization code
33 ;;; ------------------------
34 ;;; This implements the BASIC authorization type. See the online
35 ;;; documentation at
36 ;;; http://www.w3.org/hypertext/WWW/AccessAuthorization/Basic.html
37 ;;; for the complete documentation on this type.
38 ;;;
39 ;;; This is very insecure, but it works as a proof-of-concept
40 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
41 (defvar url-basic-auth-storage nil
42 "Where usernames and passwords are stored. Its value is an assoc list of
43 assoc lists. The first assoc list is keyed by the server name. The cdr of
44 this is an assoc list based on the 'directory' specified by the url we are
45 looking up.")
46
47 (defun url-basic-auth (url &optional prompt overwrite realm args)
48 "Get the username/password for the specified URL.
49 If optional argument PROMPT is non-nil, ask for the username/password
50 to use for the url and its descendants. If optional third argument
51 OVERWRITE is non-nil, overwrite the old username/password pair if it
52 is found in the assoc list. If REALM is specified, use that as the realm
53 instead of the pathname inheritance method."
54 (let* ((href (if (stringp url)
55 (url-generic-parse-url url)
56 url))
57 (server (or (url-host href) url-current-server))
58 (port (or (url-port href) "80"))
59 (path (url-filename href))
60 user pass byserv retval data)
61 (setq server (concat server ":" port)
62 path (cond
63 (realm realm)
64 ((string-match "/$" path) path)
65 (t (url-basepath path)))
66 byserv (cdr-safe (assoc server url-basic-auth-storage)))
67 (cond
68 ((and prompt (not byserv))
69 (setq user (read-string "Username: " (user-real-login-name))
70 pass (funcall url-passwd-entry-func "Password: ")
71 url-basic-auth-storage
72 (cons (list server
73 (cons path
74 (setq retval
75 (base64-encode
76 (format "%s:%s" user pass)))))
77 url-basic-auth-storage)))
78 (byserv
79 (setq retval (cdr-safe (assoc path byserv)))
80 (if (and (not retval)
81 (string-match "/" path))
82 (while (and byserv (not retval))
83 (setq data (car (car byserv)))
84 (if (or (not (string-match "/" data)) ; Its a realm - take it!
85 (and
86 (>= (length path) (length data))
87 (string= data (substring path 0 (length data)))))
88 (setq retval (cdr (car byserv))))
89 (setq byserv (cdr byserv))))
90 (if (or (and (not retval) prompt) overwrite)
91 (progn
92 (setq user (read-string "Username: " (user-real-login-name))
93 pass (funcall url-passwd-entry-func "Password: ")
94 retval (base64-encode (format "%s:%s" user pass))
95 byserv (assoc server url-basic-auth-storage))
96 (setcdr byserv
97 (cons (cons path retval) (cdr byserv))))))
98 (t (setq retval nil)))
99 (if retval (setq retval (concat "Basic " retval)))
100 retval))
101
102 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
103 ;;; Digest authorization code
104 ;;; ------------------------
105 ;;; This implements the DIGEST authorization type. See the internet draft
106 ;;; ftp://ds.internic.net/internet-drafts/draft-ietf-http-digest-aa-01.txt
107 ;;; for the complete documentation on this type.
108 ;;;
109 ;;; This is very secure
110 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
111 (defvar url-digest-auth-storage nil
112 "Where usernames and passwords are stored. Its value is an assoc list of
113 assoc lists. The first assoc list is keyed by the server name. The cdr of
114 this is an assoc list based on the 'directory' specified by the url we are
115 looking up.")
116
117 (defun url-digest-auth-create-key (username password realm method uri)
118 "Create a key for digest authentication method"
119 (let* ((info (if (stringp uri)
120 (url-generic-parse-url uri)
121 uri))
122 (a1 (md5 (concat username ":" realm ":" password)))
123 (a2 (md5 (concat method ":" (url-filename info)))))
124 (list a1 a2)))
125
126 (defun url-digest-auth (url &optional prompt overwrite realm args)
127 "Get the username/password for the specified URL.
128 If optional argument PROMPT is non-nil, ask for the username/password
129 to use for the url and its descendants. If optional third argument
130 OVERWRITE is non-nil, overwrite the old username/password pair if it
131 is found in the assoc list. If REALM is specified, use that as the realm
132 instead of hostname:portnum."
133 (if args
134 (let* ((href (if (stringp url)
135 (url-generic-parse-url url)
136 url))
137 (server (or (url-host href) url-current-server))
138 (port (or (url-port href) "80"))
139 (path (url-filename href))
140 user pass byserv retval data)
141 (setq path (cond
142 (realm realm)
143 ((string-match "/$" path) path)
144 (t (url-basepath path)))
145 server (concat server ":" port)
146 byserv (cdr-safe (assoc server url-digest-auth-storage)))
147 (cond
148 ((and prompt (not byserv))
149 (setq user (read-string "Username: " (user-real-login-name))
150 pass (funcall url-passwd-entry-func "Password: ")
151 url-digest-auth-storage
152 (cons (list server
153 (cons path
154 (setq retval
155 (cons user
156 (url-digest-auth-create-key
157 user pass realm
158 (or url-request-method "GET")
159 url)))))
160 url-digest-auth-storage)))
161 (byserv
162 (setq retval (cdr-safe (assoc path byserv)))
163 (if (and (not retval) ; no exact match, check directories
164 (string-match "/" path)) ; not looking for a realm
165 (while (and byserv (not retval))
166 (setq data (car (car byserv)))
167 (if (or (not (string-match "/" data))
168 (and
169 (>= (length path) (length data))
170 (string= data (substring path 0 (length data)))))
171 (setq retval (cdr (car byserv))))
172 (setq byserv (cdr byserv))))
173 (if (or (and (not retval) prompt) overwrite)
174 (progn
175 (setq user (read-string "Username: " (user-real-login-name))
176 pass (funcall url-passwd-entry-func "Password: ")
177 retval (setq retval
178 (cons user
179 (url-digest-auth-create-key
180 user pass realm
181 (or url-request-method "GET")
182 url)))
183 byserv (assoc server url-digest-auth-storage))
184 (setcdr byserv
185 (cons (cons path retval) (cdr byserv))))))
186 (t (setq retval nil)))
187 (if retval
188 (let ((nonce (or (cdr-safe (assoc "nonce" args)) "nonegiven"))
189 (opaque (or (cdr-safe (assoc "opaque" args)) "nonegiven")))
190 (format
191 (concat "Digest username=\"%s\", realm=\"%s\","
192 "nonce=\"%s\", uri=\"%s\","
193 "response=\"%s\", opaque=\"%s\"")
194 (nth 0 retval) realm nonce (url-filename href)
195 (md5 (concat (nth 1 retval) ":" nonce ":"
196 (nth 2 retval))) opaque))))))
197
198 (defvar url-registered-auth-schemes nil
199 "A list of the registered authorization schemes and various and sundry
200 information associated with them.")
201
202 (defun url-get-authentication (url realm type prompt &optional args)
203 "Return an authorization string suitable for use in the WWW-Authenticate
204 header in an HTTP/1.0 request.
205
206 URL is the url you are requesting authorization to. This can be either a
207 string representing the URL, or the parsed representation returned by
208 `url-generic-parse-url'
209 REALM is the realm at a specific site we are looking for. This should be a
210 string specifying the exact realm, or nil or the symbol 'any' to
211 specify that the filename portion of the URL should be used as the
212 realm
213 TYPE is the type of authentication to be returned. This is either a string
214 representing the type (basic, digest, etc), or nil or the symbol 'any'
215 to specify that any authentication is acceptable. If requesting 'any'
216 the strongest matching authentication will be returned. If this is
217 wrong, its no big deal, the error from the server will specify exactly
218 what type of auth to use
219 PROMPT is boolean - specifies whether to ask the user for a username/password
220 if one cannot be found in the cache"
221 (if (not realm)
222 (setq realm (cdr-safe (assoc "realm" args))))
223 (if (stringp url)
224 (setq url (url-generic-parse-url url)))
225 (if (or (null type) (eq type 'any))
226 ;; Whooo doogies!
227 ;; Go through and get _all_ the authorization strings that could apply
228 ;; to this URL, store them along with the 'rating' we have in the list
229 ;; of schemes, then sort them so that the 'best' is at the front of the
230 ;; list, then get the car, then get the cdr.
231 ;; Zooom zooom zoooooom
232 (cdr-safe
233 (car-safe
234 (sort
235 (mapcar
236 (function
237 (lambda (scheme)
238 (if (fboundp (car (cdr scheme)))
239 (cons (cdr (cdr scheme))
240 (funcall (car (cdr scheme)) url nil nil realm))
241 (cons 0 nil))))
242 url-registered-auth-schemes)
243 (function
244 (lambda (x y)
245 (cond
246 ((null (cdr x)) nil)
247 ((and (cdr x) (null (cdr y))) t)
248 ((and (cdr x) (cdr y))
249 (>= (car x) (car y)))
250 (t nil)))))))
251 (if (symbolp type) (setq type (symbol-name type)))
252 (let* ((scheme (car-safe
253 (cdr-safe (assoc (downcase type)
254 url-registered-auth-schemes)))))
255 (if (and scheme (fboundp scheme))
256 (funcall scheme url prompt
257 (and prompt
258 (funcall scheme url nil nil realm args))
259 realm args)))))
260
261 (defun url-register-auth-scheme (type &optional function rating)
262 "Register an HTTP authentication method.
263
264 TYPE is a string or symbol specifying the name of the method. This
265 should be the same thing you expect to get returned in an Authenticate
266 header in HTTP/1.0 - it will be downcased.
267 FUNCTION is the function to call to get the authorization information. This
268 defaults to `url-?-auth', where ? is TYPE
269 RATING a rating between 1 and 10 of the strength of the authentication.
270 This is used when asking for the best authentication for a specific
271 URL. The item with the highest rating is returned."
272 (let* ((type (cond
273 ((stringp type) (downcase type))
274 ((symbolp type) (downcase (symbol-name type)))
275 (t (error "Bad call to `url-register-auth-scheme'"))))
276 (function (or function (intern (concat "url-" type "-auth"))))
277 (rating (cond
278 ((null rating) 2)
279 ((stringp rating) (string-to-int rating))
280 (t rating)))
281 (node (assoc type url-registered-auth-schemes)))
282 (if (not (fboundp function))
283 (url-warn 'security
284 (format (eval-when-compile
285 "Tried to register `%s' as an auth scheme"
286 ", but it is not a function!") function)))
287
288 (if node
289 (progn
290 (setcdr node (cons function rating))
291 (url-warn 'security
292 (format
293 "Replacing authorization method `%s' - this could be bad."
294 type)))
295 (setq url-registered-auth-schemes
296 (cons (cons type (cons function rating))
297 url-registered-auth-schemes)))))
298
299 (defun url-auth-registered (scheme)
300 ;; Return non-nil iff SCHEME is registered as an auth type
301 (assoc scheme url-registered-auth-schemes))
302
303 (provide 'urlauth)