lisp/gnus/auth-source.el

   1 ;;; auth-source.el --- authentication sources for Gnus and Emacs
   2
   3 ;; Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
   4
   5 ;; Author: Ted Zlatanov <tzz@lifelogs.com>
   6 ;; Keywords: news
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; This is the auth-source.el package.  It lets users tell Gnus how to
  26 ;; authenticate in a single place.  Simplicity is the goal.  Instead
  27 ;; of providing 5000 options, we'll stick to simple, easy to
  28 ;; understand options.
  29
  30 ;; See the auth.info Info documentation for details.
  31
  32 ;; TODO:
  33
  34 ;; - never decode the backend file unless it's necessary
  35 ;; - a more generic way to match backends and search backend contents
  36 ;; - absorb netrc.el and simplify it
  37 ;; - protect passwords better
  38 ;; - allow creating and changing netrc lines (not files) e.g. change a password
  39
  40 ;;; Code:
  41
  42 (require 'gnus-util)
  43 (require 'netrc)
  44
  45 (eval-when-compile (require 'cl))
  46 (autoload 'secrets-create-item "secrets")
  47 (autoload 'secrets-delete-item "secrets")
  48 (autoload 'secrets-get-alias "secrets")
  49 (autoload 'secrets-get-attribute "secrets")
  50 (autoload 'secrets-get-secret "secrets")
  51 (autoload 'secrets-list-collections "secrets")
  52 (autoload 'secrets-search-items "secrets")
  53
  54 (defgroup auth-source nil
  55   "Authentication sources."
  56   :version "23.1" ;; No Gnus
  57   :group 'gnus)
  58
  59 (defcustom auth-source-protocols '((imap "imap" "imaps" "143" "993")
  60                                    (pop3 "pop3" "pop" "pop3s" "110" "995")
  61                                    (ssh  "ssh" "22")
  62                                    (sftp "sftp" "115")
  63                                    (smtp "smtp" "25"))
  64   "List of authentication protocols and their names"
  65
  66   :group 'auth-source
  67   :version "23.2" ;; No Gnus
  68   :type '(repeat :tag "Authentication Protocols"
  69                  (cons :tag "Protocol Entry"
  70                        (symbol :tag "Protocol")
  71                        (repeat :tag "Names"
  72                                (string :tag "Name")))))
  73
  74 ;;; generate all the protocols in a format Customize can use
  75 ;;; TODO: generate on the fly from auth-source-protocols
  76 (defconst auth-source-protocols-customize
  77   (mapcar (lambda (a)
  78             (let ((p (car-safe a)))
  79               (list 'const
  80                     :tag (upcase (symbol-name p))
  81                     p)))
  82           auth-source-protocols))
  83
  84 (defvar auth-source-cache (make-hash-table :test 'equal)
  85   "Cache for auth-source data")
  86
  87 (defcustom auth-source-do-cache t
  88   "Whether auth-source should cache information."
  89   :group 'auth-source
  90   :version "23.2" ;; No Gnus
  91   :type `boolean)
  92
  93 (defcustom auth-source-debug nil
  94   "Whether auth-source should log debug messages.
  95 Also see `auth-source-hide-passwords'.
  96
  97 If the value is nil, debug messages are not logged.
  98 If the value is t, debug messages are logged with `message'.
  99  In that case, your authentication data will be in the
 100  clear (except for passwords, which are always stripped out).
 101 If the value is a function, debug messages are logged by calling
 102  that function using the same arguments as `message'."
 103   :group 'auth-source
 104   :version "23.2" ;; No Gnus
 105   :type `(choice
 106           :tag "auth-source debugging mode"
 107           (const :tag "Log using `message' to the *Messages* buffer" t)
 108           (function :tag "Function that takes arguments like `message'")
 109           (const :tag "Don't log anything" nil)))
 110
 111 (defcustom auth-source-hide-passwords t
 112   "Whether auth-source should hide passwords in log messages.
 113 Only relevant if `auth-source-debug' is not nil."
 114   :group 'auth-source
 115   :version "23.2" ;; No Gnus
 116   :type `boolean)
 117
 118 (defcustom auth-sources '((:source "~/.authinfo.gpg")
 119                           (:source "~/.authinfo"))
 120   "List of authentication sources.
 121
 122 The default will get login and password information from a .gpg
 123 file, which you should set up with the EPA/EPG packages to be
 124 encrypted.  See the auth.info manual for details.
 125
 126 Each entry is the authentication type with optional properties.
 127
 128 It's best to customize this with `M-x customize-variable' because the choices
 129 can get pretty complex."
 130   :group 'auth-source
 131   :version "23.2" ;; No Gnus
 132   :type `(repeat :tag "Authentication Sources"
 133                  (list :tag "Source definition"
 134                        (const :format "" :value :source)
 135                        (choice :tag "Authentication backend choice"
 136                                (string :tag "Authentication Source (file)")
 137                                (list :tag "secrets.el (Secret Service API/KWallet/GNOME Keyring)"
 138                                      (const :format "" :value :secrets)
 139                                      (choice :tag "Collection to use"
 140                                              (string :tag "Collection name")
 141                                              (const :tag "Default" 'default)
 142                                              (const :tag "Login" "login")
 143                                              (const :tag "Temporary" "session"))))
 144                        (repeat :tag "Extra Parameters" :inline t
 145                                (choice :tag "Extra parameter"
 146                                        (list :tag "Host (omit to match as a fallback)"
 147                                              (const :format "" :value :host)
 148                                              (choice :tag "Host (machine) choice"
 149                                                      (const :tag "Any" t)
 150                                                      (regexp :tag "Host (machine) regular expression")))
 151                                        (list :tag "Protocol (omit to match as a fallback)"
 152                                              (const :format "" :value :protocol)
 153                                              (choice :tag "Protocol"
 154                                                      (const :tag "Any" t)
 155                                                      ,@auth-source-protocols-customize))
 156                                        (list :tag "User  (omit to match as a fallback)" :inline t
 157                                              (const :format "" :value :user)
 158                                              (choice :tag "Personality or username"
 159                                                      (const :tag "Any" t)
 160                                                      (string :tag "Specific user name"))))))))
 161
 162 ;; temp for debugging
 163 ;; (unintern 'auth-source-protocols)
 164 ;; (unintern 'auth-sources)
 165 ;; (customize-variable 'auth-sources)
 166 ;; (setq auth-sources nil)
 167 ;; (format "%S" auth-sources)
 168 ;; (customize-variable 'auth-source-protocols)
 169 ;; (setq auth-source-protocols nil)
 170 ;; (format "%S" auth-source-protocols)
 171 ;; (auth-source-pick nil :host "a" :port 'imap)
 172 ;; (auth-source-user-or-password "login" "imap.myhost.com" 'imap)
 173 ;; (auth-source-user-or-password "password" "imap.myhost.com" 'imap)
 174 ;; (auth-source-user-or-password-imap "login" "imap.myhost.com")
 175 ;; (auth-source-user-or-password-imap "password" "imap.myhost.com")
 176 ;; (auth-source-protocol-defaults 'imap)
 177
 178 ;; (let ((auth-source-debug 'debug)) (auth-source-debug "hello"))
 179 ;; (let ((auth-source-debug t)) (auth-source-debug "hello"))
 180 ;; (let ((auth-source-debug nil)) (auth-source-debug "hello"))
 181 (defun auth-source-do-debug (&rest msg)
 182   ;; set logger to either the function in auth-source-debug or 'message
 183   ;; note that it will be 'message if auth-source-debug is nil, so
 184   ;; we also check the value
 185   (when auth-source-debug
 186     (let ((logger (if (functionp auth-source-debug)
 187                       auth-source-debug
 188                     'message)))
 189       (apply logger msg))))
 190
 191 ;; (auth-source-pick nil :host "any" :protocol 'imap :user "joe")
 192 ;; (auth-source-pick t :host "any" :protocol 'imap :user "joe")
 193 ;; (setq auth-sources '((:source (:secrets default) :host t :protocol t :user "joe")
 194 ;;                   (:source (:secrets "session") :host t :protocol t :user "joe")
 195 ;;                   (:source (:secrets "login") :host t :protocol t)
 196 ;;                   (:source "~/.authinfo.gpg" :host t :protocol t)))
 197
 198 ;; (setq auth-sources '((:source (:secrets default) :host t :protocol t :user "joe")
 199 ;;                   (:source (:secrets "session") :host t :protocol t :user "joe")
 200 ;;                   (:source (:secrets "login") :host t :protocol t)
 201 ;;                   ))
 202
 203 ;; (setq auth-sources '((:source "~/.authinfo.gpg" :host t :protocol t)))
 204
 205 (defun auth-get-source (entry)
 206   "Return the source string of ENTRY, which is one entry in `auth-sources'.
 207 If it is a Secret Service API, return the collection name, otherwise
 208 the file name."
 209   (let ((source (plist-get entry :source)))
 210     (if (stringp source)
 211         source
 212       ;; Secret Service API.
 213       (setq source (plist-get source :secrets))
 214       (when (eq source 'default)
 215         (setq source (or (secrets-get-alias "default") "login")))
 216       (or source "session"))))
 217
 218 (defun auth-source-pick (&rest spec)
 219   "Parse `auth-sources' for matches of the SPEC plist.
 220
 221 Common keys are :host, :protocol, and :user.  A value of t in
 222 SPEC means to always succeed in the match.  A string value is
 223 matched as a regex."
 224   (let ((keys (loop for i below (length spec) by 2 collect (nth i spec)))
 225         choices)
 226     (dolist (choice (copy-tree auth-sources) choices)
 227       (let ((source (plist-get choice :source))
 228             (match t))
 229         (when
 230             (and
 231              ;; Check existence of source.
 232              (if (consp source)
 233                  ;; Secret Service API.
 234                  (member (auth-get-source choice) (secrets-list-collections))
 235                ;; authinfo file.
 236                (file-exists-p source))
 237
 238              ;; Check keywords.
 239              (dolist (k keys match)
 240                (let* ((v (plist-get spec k))
 241                       (choicev (if (plist-member choice k)
 242                                    (plist-get choice k) t)))
 243                  (setq match
 244                        (and match
 245                             (or
 246                              ;; source always matches spec key
 247                              (eq t choicev)
 248                              ;; source key gives regex to match against spec
 249                              (and (stringp choicev) (string-match choicev v))
 250                              ;; source key gives symbol to match against spec
 251                              (and (symbolp choicev) (eq choicev v))))))))
 252
 253           (add-to-list 'choices choice 'append))))))
 254
 255 (defun auth-source-retrieve (mode entry &rest spec)
 256   "Retrieve MODE credentials according to SPEC from ENTRY."
 257   (catch 'no-password
 258     (let ((host (plist-get spec :host))
 259           (user (plist-get spec :user))
 260           (prot (plist-get spec :protocol))
 261           (source (plist-get entry :source))
 262           result)
 263       (cond
 264        ;; Secret Service API.
 265        ((consp source)
 266         (let ((coll (auth-get-source entry))
 267               item)
 268           ;; Loop over candidates with a matching host attribute.
 269           (dolist (elt (secrets-search-items coll :host host) item)
 270             (when (and (or (not user)
 271                            (string-equal
 272                             user (secrets-get-attribute coll elt :user)))
 273                        (or (not prot)
 274                            (string-equal
 275                             prot (secrets-get-attribute coll elt :protocol))))
 276               (setq item elt)
 277               (return elt)))
 278           ;; Compose result.
 279           (when item
 280             (setq result
 281                   (mapcar (lambda (m)
 282                             (if (string-equal "password" m)
 283                                 (or (secrets-get-secret coll item)
 284                                     ;; When we do not find a password,
 285                                     ;; we return nil anyway.
 286                                     (throw 'no-password nil))
 287                               (or (secrets-get-attribute coll item :user)
 288                                   user)))
 289                           (if (consp mode) mode (list mode)))))
 290           (if (consp mode) result (car result))))
 291        ;; Anything else is netrc.
 292        (t
 293         (let ((search (list source (list host) (list (format "%s" prot))
 294                             (auth-source-protocol-defaults prot))))
 295           (setq result
 296                 (mapcar (lambda (m)
 297                           (if (string-equal "password" m)
 298                               (or (apply
 299                                    'netrc-machine-user-or-password m search)
 300                                   ;; When we do not find a password, we
 301                                   ;; return nil anyway.
 302                                   (throw 'no-password nil))
 303                             (or (apply
 304                                  'netrc-machine-user-or-password m search)
 305                                 user)))
 306                         (if (consp mode) mode (list mode)))))
 307         (if (consp mode) result (car result)))))))
 308
 309 (defun auth-source-create (mode entry &rest spec)
 310   "Create interactively credentials according to SPEC in ENTRY.
 311 Return structure as specified by MODE."
 312   (let* ((host (plist-get spec :host))
 313          (user (plist-get spec :user))
 314          (prot (plist-get spec :protocol))
 315          (source (plist-get entry :source))
 316          (name (concat (if user (format "%s@" user))
 317                        host
 318                        (if prot (format ":%s" prot))))
 319          result)
 320     (setq result
 321           (mapcar
 322            (lambda (m)
 323              (cons
 324               m
 325               (cond
 326                ((equal "password" m)
 327                 (let ((passwd (read-passwd
 328                                (format "Password for %s on %s: " prot host))))
 329                   (cond
 330                    ;; Secret Service API.
 331                    ((consp source)
 332                     (apply
 333                      'secrets-create-item
 334                      (auth-get-source entry) name passwd spec))
 335                    (t)) ;; netrc not implemented yes.
 336                   passwd))
 337                ((equal "login" m)
 338                 (or user
 339                     (read-string
 340                      (format "User name for %s on %s (default %s): " prot host
 341                              (user-login-name))
 342                      nil nil (user-login-name))))
 343                (t
 344                 "unknownuser"))))
 345            (if (consp mode) mode (list mode))))
 346     ;; Allow the source to save the data.
 347     (cond
 348      ((consp source)
 349       ;; Secret Service API -- not implemented.
 350       )
 351      (t
 352       ;; netrc interface.
 353       (when (y-or-n-p (format "Do you want to save this password in %s? "
 354                               source))
 355         (netrc-store-data source host prot
 356                           (or user (cdr (assoc "login" result)))
 357                           (cdr (assoc "password" result))))))
 358     (if (consp mode)
 359         (mapcar #'cdr result)
 360       (cdar result))))
 361
 362 (defun auth-source-delete (entry &rest spec)
 363   "Delete credentials according to SPEC in ENTRY."
 364   (let ((host (plist-get spec :host))
 365         (user (plist-get spec :user))
 366         (prot (plist-get spec :protocol))
 367         (source (plist-get entry :source)))
 368     (cond
 369      ;; Secret Service API.
 370      ((consp source)
 371       (let ((coll (auth-get-source entry)))
 372         ;; Loop over candidates with a matching host attribute.
 373         (dolist (elt (secrets-search-items coll :host host))
 374           (when (and (or (not user)
 375                          (string-equal
 376                           user (secrets-get-attribute coll elt :user)))
 377                      (or (not prot)
 378                          (string-equal
 379                           prot (secrets-get-attribute coll elt :protocol))))
 380             (secrets-delete-item coll elt)))))
 381      (t)))) ;; netrc not implemented yes.
 382
 383 (defun auth-source-forget-user-or-password
 384   (mode host protocol &optional username)
 385   "Remove cached authentication token."
 386   (interactive "slogin/password: \nsHost: \nsProtocol: \n") ;for testing
 387   (remhash
 388    (if username
 389        (format "%s %s:%s %s" mode host protocol username)
 390      (format "%s %s:%s" mode host protocol))
 391    auth-source-cache))
 392
 393 (defun auth-source-forget-all-cached ()
 394   "Forget all cached auth-source authentication tokens."
 395   (interactive)
 396   (setq auth-source-cache (make-hash-table :test 'equal)))
 397
 398 ;; (progn
 399 ;;   (auth-source-forget-all-cached)
 400 ;;   (list
 401 ;;    (auth-source-user-or-password '("login" "password") "imap.myhost.com" "other")
 402 ;;    (auth-source-user-or-password '("login" "password") "imap.myhost.com" "other" "tzz")
 403 ;;    (auth-source-user-or-password '("login" "password") "imap.myhost.com" "other" "joe")))
 404
 405 (defun auth-source-user-or-password
 406   (mode host protocol &optional username create-missing delete-existing)
 407   "Find MODE (string or list of strings) matching HOST and PROTOCOL.
 408
 409 USERNAME is optional and will be used as \"login\" in a search
 410 across the Secret Service API (see secrets.el) if the resulting
 411 items don't have a username.  This means that if you search for
 412 username \"joe\" and it matches an item but the item doesn't have
 413 a :user attribute, the username \"joe\" will be returned.
 414
 415 A non nil DELETE-EXISTING means deleting any matching password
 416 entry in the respective sources.  This is useful only when
 417 CREATE-MISSING is non nil as well; the intended use case is to
 418 remove wrong password entries.
 419
 420 If no matching entry is found, and CREATE-MISSING is non nil,
 421 the password will be retrieved interactively, and it will be
 422 stored in the password database which matches best (see
 423 `auth-sources').
 424
 425 MODE can be \"login\" or \"password\"."
 426   (auth-source-do-debug
 427    "auth-source-user-or-password: get %s for %s (%s) + user=%s"
 428    mode host protocol username)
 429   (let* ((listy (listp mode))
 430          (mode (if listy mode (list mode)))
 431          (cname (if username
 432                     (format "%s %s:%s %s" mode host protocol username)
 433                   (format "%s %s:%s" mode host protocol)))
 434          (search (list :host host :protocol protocol))
 435          (search (if username (append search (list :user username)) search))
 436          (found (if (not delete-existing)
 437                     (gethash cname auth-source-cache)
 438                   (remhash cname auth-source-cache)
 439                   nil)))
 440     (if found
 441         (progn
 442           (auth-source-do-debug
 443            "auth-source-user-or-password: cached %s=%s for %s (%s) + %s"
 444            mode
 445            ;; don't show the password
 446            (if (and (member "password" mode) auth-source-hide-passwords)
 447                "SECRET"
 448              found)
 449            host protocol username)
 450           found)                        ; return the found data
 451       ;; else, if not found
 452       (let ((choices (apply 'auth-source-pick search)))
 453         (dolist (choice choices)
 454           (if delete-existing
 455               (apply 'auth-source-delete choice search)
 456             (setq found (apply 'auth-source-retrieve mode choice search)))
 457           (and found (return found)))
 458
 459         ;; We haven't found something, so we will create it interactively.
 460         (when (and (not found) create-missing)
 461           (setq found (apply 'auth-source-create
 462                              mode (if choices
 463                                       (car choices)
 464                                     (car auth-sources))
 465                              search)))
 466
 467         ;; Cache the result.
 468         (when found
 469           (auth-source-do-debug
 470            "auth-source-user-or-password: found %s=%s for %s (%s) + %s"
 471            mode
 472            ;; don't show the password
 473            (if (and (member "password" mode) auth-source-hide-passwords)
 474                "SECRET" found)
 475            host protocol username)
 476           (setq found (if listy found (car-safe found)))
 477           (when auth-source-do-cache
 478             (puthash cname found auth-source-cache)))
 479
 480         found))))
 481
 482 (defun auth-source-protocol-defaults (protocol)
 483   "Return a list of default ports and names for PROTOCOL."
 484   (cdr-safe (assoc protocol auth-source-protocols)))
 485
 486 (defun auth-source-user-or-password-imap (mode host)
 487   (auth-source-user-or-password mode host 'imap))
 488
 489 (defun auth-source-user-or-password-pop3 (mode host)
 490   (auth-source-user-or-password mode host 'pop3))
 491
 492 (defun auth-source-user-or-password-ssh (mode host)
 493   (auth-source-user-or-password mode host 'ssh))
 494
 495 (defun auth-source-user-or-password-sftp (mode host)
 496   (auth-source-user-or-password mode host 'sftp))
 497
 498 (defun auth-source-user-or-password-smtp (mode host)
 499   (auth-source-user-or-password mode host 'smtp))
 500
 501 (provide 'auth-source)
 502
 503 ;;; auth-source.el ends here