Identify unsafe combinations of Bcc and encryption
[gnus] / lisp / sieve-manage.el
index 51f55ba..72f22e7 100644 (file)
@@ -1,31 +1,34 @@
-;;; sieve-manage.el --- Implementation of the managesive protocol in elisp
-;; Copyright (C) 2001 Free Software Foundation, Inc.
+;;; sieve-manage.el --- Implementation of the managesieve protocol in elisp
+
+;; Copyright (C) 2001-2015 Free Software Foundation, Inc.
 
 ;; Author: Simon Josefsson <simon@josefsson.org>
+;;         Albert Krewinkel <tarleb@moltkeplatz.de>
 
-;; This file is not part of GNU Emacs, but the same permissions apply.
+;; This file is part of GNU Emacs.
 
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs is free software: you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
-;; any later version.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
 
 ;; GNU Emacs is distributed in the hope that it will be useful,
 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.         See the
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING.  If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 
 ;;; Commentary:
 
 ;; This library provides an elisp API for the managesieve network
 ;; protocol.
 ;;
-;; Currently only the CRAM-MD5 authentication mechanism is supported.
+;; It uses the SASL library for authentication, which means it
+;; supports DIGEST-MD5, CRAM-MD5, SCRAM-MD5, NTLM, PLAIN and LOGIN
+;; methods.  STARTTLS is not well tested, but should be easy to get to
+;; work if someone wants.
 ;;
 ;; The API should be fairly obvious for anyone familiar with the
 ;; managesieve protocol, interface functions include:
 ;; `sieve-manage-close'
 ;; close a server connection.
 ;;
-;; `sieve-manage-authenticate'
 ;; `sieve-manage-listscripts'
+;; `sieve-manage-deletescript'
+;; `sieve-manage-getscript'
 ;; performs managesieve protocol actions
 ;;
 ;; and that's it.  Example of a managesieve session in *scratch*:
 ;;
-;; (setq my-buf (sieve-manage-open "my.server.com"))
-;; " *sieve* my.server.com:2000*"
-;;
-;; (sieve-manage-authenticate "myusername" "mypassword" my-buf)
-;; 'auth
+;; (with-current-buffer (sieve-manage-open "mail.example.com")
+;;   (sieve-manage-authenticate)
+;;   (sieve-manage-listscripts))
 ;;
-;; (sieve-manage-listscripts my-buf)
-;; ("vacation" "testscript" ("splitmail") "badscript")
+;; => ((active . "main") "vacation")
 ;;
 ;; References:
 ;;
 ;; Release history:
 ;;
 ;; 2001-10-31 Committed to Oort Gnus.
-;;
-;; $Id: sieve-manage.el,v 6.1 2001/11/01 00:50:22 jas Exp $
+;; 2002-07-27 Added DELETESCRIPT.  Suggested by Ned Ludd.
+;; 2002-08-03 Use SASL library.
+;; 2013-06-05 Enabled STARTTLS support, fixed bit rot.
 
 ;;; Code:
 
-(require 'rfc2104)
-(or (fboundp 'md5)
-    (require 'md5))
-(eval-and-compile
-  (autoload 'starttls-open-stream "starttls"))
+(if (locate-library "password-cache")
+    (require 'password-cache)
+  (require 'password))
+
+(eval-when-compile
+  (require 'cl)                                ; caddr
+  (require 'sasl)
+  (require 'starttls))
+(autoload 'sasl-find-mechanism "sasl")
+(autoload 'auth-source-search "auth-source")
 
 ;; User customizable variables:
 
 
 (defcustom sieve-manage-log "*sieve-manage-log*"
   "Name of buffer for managesieve session trace."
-  :type 'string)
-
-(defcustom sieve-manage-default-user (user-login-name)
-  "Default username to use."
-  :type 'string)
+  :type 'string
+  :group 'sieve-manage)
 
 (defcustom sieve-manage-server-eol "\r\n"
   "The EOL string sent from the server."
-  :type 'string)
+  :type 'string
+  :group 'sieve-manage)
 
 (defcustom sieve-manage-client-eol "\r\n"
   "The EOL string we send to the server."
-  :type 'string)
-
-(defcustom sieve-manage-streams '(network starttls shell)
-  "Priority of streams to consider when opening connection to server.")
-
-(defcustom sieve-manage-stream-alist
-  '((network   sieve-manage-network-p          sieve-manage-network-open)
-    (shell     sieve-manage-shell-p            sieve-manage-shell-open)
-    (starttls  sieve-manage-starttls-p         sieve-manage-starttls-open))
-  "Definition of network streams.
-
-(NAME CHECK OPEN)
-
-NAME names the stream, CHECK is a function returning non-nil if the
-server support the stream and OPEN is a function for opening the
-stream.")
-
-(defcustom sieve-manage-authenticators '(cram-md5 plain)
-  "Priority of authenticators to consider when authenticating to server.")
-
-(defcustom sieve-manage-authenticator-alist 
+  :type 'string
+  :group 'sieve-manage)
+
+(defcustom sieve-manage-authenticators '(digest-md5
+                                        cram-md5
+                                        scram-md5
+                                        ntlm
+                                        plain
+                                        login)
+  "Priority of authenticators to consider when authenticating to server."
+  ;; FIXME Improve this.  It's not `set'.
+  ;; It's like (repeat (choice (const ...))), where each choice can
+  ;; only appear once.
+  :type '(repeat symbol)
+  :group 'sieve-manage)
+
+(defcustom sieve-manage-authenticator-alist
   '((cram-md5   sieve-manage-cram-md5-p       sieve-manage-cram-md5-auth)
-    (plain      sieve-manage-plain-p          sieve-manage-plain-auth))
+    (digest-md5 sieve-manage-digest-md5-p     sieve-manage-digest-md5-auth)
+    (scram-md5  sieve-manage-scram-md5-p      sieve-manage-scram-md5-auth)
+    (ntlm       sieve-manage-ntlm-p           sieve-manage-ntlm-auth)
+    (plain      sieve-manage-plain-p          sieve-manage-plain-auth)
+    (login      sieve-manage-login-p          sieve-manage-login-auth))
   "Definition of authenticators.
 
-(NAME CHECK AUTHENTICATE)
+\(NAME CHECK AUTHENTICATE)
 
 NAME names the authenticator.  CHECK is a function returning non-nil if
 the server support the authenticator and AUTHENTICATE is a function
-for doing the actuall authentification.")
-
-(defcustom sieve-manage-default-port 2000
-  "Default port number for managesieve protocol."
-  :type 'integer)
+for doing the actual authentication."
+  :type '(repeat (list (symbol :tag "Name") (function :tag "Check function")
+                      (function :tag "Authentication function")))
+  :group 'sieve-manage)
+
+(defcustom sieve-manage-default-port "sieve"
+  "Default port number or service name for managesieve protocol."
+  :type '(choice integer string)
+  :version "24.4"
+  :group 'sieve-manage)
+
+(defcustom sieve-manage-default-stream 'network
+  "Default stream type to use for `sieve-manage'."
+  :version "24.1"
+  :type 'symbol
+  :group 'sieve-manage)
 
 ;; Internal variables:
 
@@ -137,21 +153,16 @@ for doing the actuall authentification.")
                                         sieve-manage-port
                                         sieve-manage-auth
                                         sieve-manage-stream
-                                        sieve-manage-username
-                                        sieve-manage-password
                                         sieve-manage-process
                                         sieve-manage-client-eol
                                         sieve-manage-server-eol
                                         sieve-manage-capability))
-(defconst sieve-manage-default-stream 'network)
 (defconst sieve-manage-coding-system-for-read 'binary)
 (defconst sieve-manage-coding-system-for-write 'binary)
 (defvar sieve-manage-stream nil)
 (defvar sieve-manage-auth nil)
 (defvar sieve-manage-server nil)
 (defvar sieve-manage-port nil)
-(defvar sieve-manage-username nil)
-(defvar sieve-manage-password nil)
 (defvar sieve-manage-state 'closed
   "Managesieve state.
 Valid states are `closed', `initial', `nonauth', and `auth'.")
@@ -159,78 +170,23 @@ Valid states are `closed', `initial', `nonauth', and `auth'.")
 (defvar sieve-manage-capability nil)
 
 ;; Internal utility functions
-
-(defsubst sieve-manage-disable-multibyte ()
-  "Enable multibyte in the current buffer."
-  (when (fboundp 'set-buffer-multibyte)
-    (set-buffer-multibyte nil)))
-
-(defun sieve-manage-read-passwd (prompt &rest args)
-  "Read a password using PROMPT.
-If ARGS, PROMPT is used as an argument to `format'."
-  (let ((prompt (if args
-                   (apply 'format prompt args)
-                 prompt)))
-    (funcall (if (or (fboundp 'read-passwd)
-                    (and (load "subr" t)
-                         (fboundp 'read-passwd))
-                    (and (load "passwd" t)
-                         (fboundp 'read-passwd)))
-                'read-passwd
-              (autoload 'ange-ftp-read-passwd "ange-ftp")
-              'ange-ftp-read-passwd)
-            prompt)))
-
-
-;; Uses the dynamically bound `reason' variable.
-(defvar reason)
-(defun sieve-manage-interactive-login (buffer loginfunc)
-  "Login to server in BUFFER.
-LOGINFUNC is passed a username and a password, it should return t if
-it where sucessful authenticating itself to the server, nil otherwise.
-Returns t if login was successful, nil otherwise."
-  (with-current-buffer buffer
-    (make-variable-buffer-local 'sieve-manage-username)
-    (make-variable-buffer-local 'sieve-manage-password)
-    (let (user passwd ret reason)
-      ;;      (condition-case ()
-      (while (or (not user) (not passwd))
-       (setq user (or sieve-manage-username
-                      (read-from-minibuffer 
-                       (concat "Managesieve username for "
-                               sieve-manage-server ": ")
-                       (or user sieve-manage-default-user))))
-       (setq passwd (or sieve-manage-password
-                        (sieve-manage-read-passwd
-                         (concat "Managesieve password for " user "@" 
-                                 sieve-manage-server ": "))))
-       (when (and user passwd)
-         (if (funcall loginfunc user passwd)
-             (progn
-               (setq ret t
-                     sieve-manage-username user)
-               (if (and (not sieve-manage-password)
-                        (y-or-n-p "Store password for this session? "))
-                   (setq sieve-manage-password passwd)))
-           (if reason
-               (message "Login failed (reason given: %s)..." reason)
-             (message "Login failed..."))
-           (setq reason nil)
-           (setq passwd nil)
-           (sit-for 1))))
-      ;;       (quit (with-current-buffer buffer
-      ;;               (setq user nil
-      ;;                     passwd nil)))
-      ;;       (error (with-current-buffer buffer
-      ;;                (setq user nil
-      ;;                      passwd nil))))
-      ret)))
+(autoload 'mm-enable-multibyte "mm-util")
+
+(defun sieve-manage-make-process-buffer ()
+  (with-current-buffer
+      (generate-new-buffer (format " *sieve %s:%s*"
+                                   sieve-manage-server
+                                   sieve-manage-port))
+    (mapc 'make-local-variable sieve-manage-local-variables)
+    (mm-enable-multibyte)
+    (buffer-disable-undo)
+    (current-buffer)))
 
 (defun sieve-manage-erase (&optional p buffer)
   (let ((buffer (or buffer (current-buffer))))
     (and sieve-manage-log
         (with-current-buffer (get-buffer-create sieve-manage-log)
-          (sieve-manage-disable-multibyte)
+          (mm-enable-multibyte)
           (buffer-disable-undo)
           (goto-char (point-max))
           (insert-buffer-substring buffer (with-current-buffer buffer
@@ -239,197 +195,197 @@ Returns t if login was successful, nil otherwise."
                                            (point-max)))))))
   (delete-region (point-min) (or p (point-max))))
 
-(defun sieve-manage-open-1 (buffer)
+(defun sieve-manage-open-server (server port &optional stream buffer)
+  "Open network connection to SERVER on PORT.
+Return the buffer associated with the connection."
   (with-current-buffer buffer
     (sieve-manage-erase)
-    (setq sieve-manage-state 'initial
-         sieve-manage-process
-         (condition-case ()
-             (funcall (nth 2 (assq sieve-manage-stream
-                                   sieve-manage-stream-alist))
-                      "sieve" buffer sieve-manage-server sieve-manage-port)
-           ((error quit) nil)))
-    (when sieve-manage-process
-      (while (and (eq sieve-manage-state 'initial)
-                 (memq (process-status sieve-manage-process) '(open run)))
-       (message "Waiting for response from %s..." sieve-manage-server)
-       (accept-process-output sieve-manage-process 1))
-      (message "Waiting for response from %s...done" sieve-manage-server)
-      (and (memq (process-status sieve-manage-process) '(open run))
-          sieve-manage-process))))
-
-;; Streams
-
-(defun sieve-manage-network-p (buffer)
-  t)
-
-(defun sieve-manage-network-open (name buffer server port)
-  (let* ((port (or port sieve-manage-default-port))
-        (coding-system-for-read sieve-manage-coding-system-for-read)
-        (coding-system-for-write sieve-manage-coding-system-for-write)
-        (process (open-network-stream name buffer server port)))
-    (when process
-      (while (and (memq (process-status process) '(open run))
-                 (set-buffer buffer) ;; XXX "blue moon" nntp.el bug
-                 (goto-char (point-min))
-                 (not (sieve-manage-parse-greeting-1)))
-       (accept-process-output process 1)
-       (sit-for 1))
-      (sieve-manage-erase nil buffer)
-      (when (memq (process-status process) '(open run))
-       process))))
-
-(defun imap-starttls-p (buffer)
-  ;;  (and (imap-capability 'STARTTLS buffer)
-  (condition-case ()
-      (progn
-       (require 'starttls)
-       (call-process "starttls"))
-    (error nil)))
-
-(defun imap-starttls-open (name buffer server port)
-  (let* ((port (or port sieve-manage-default-port))
-        (coding-system-for-read sieve-manage-coding-system-for-read)
-        (coding-system-for-write sieve-manage-coding-system-for-write)
-        (process (starttls-open-stream name buffer server port))
-        done)
-    (when process
-      (while (and (memq (process-status process) '(open run))
-                 (set-buffer buffer) ;; XXX "blue moon" nntp.el bug
-                 (goto-char (point-min))
-                 (not (sieve-manage-parse-greeting-1)))
-       (accept-process-output process 1)
-       (sit-for 1))
-      (sieve-manage-erase nil buffer)
-      (sieve-manage-send "STARTTLS")
-      (starttls-negotiate process))
-    (when (memq (process-status process) '(open run))
-      process)))
+    (setq sieve-manage-state 'initial)
+    (destructuring-bind (proc . props)
+        (open-protocol-stream
+         "SIEVE" buffer server port
+         :type stream
+         :capability-command "CAPABILITY\r\n"
+         :end-of-command "^\\(OK\\|NO\\).*\n"
+         :success "^OK.*\n"
+         :return-list t
+         :starttls-function
+         (lambda (capabilities)
+           (when (string-match "\\bSTARTTLS\\b" capabilities)
+             "STARTTLS\r\n")))
+      (setq sieve-manage-process proc)
+      (setq sieve-manage-capability
+            (sieve-manage-parse-capability (plist-get props :capabilities)))
+      ;; Ignore new capabilities issues after successful STARTTLS
+      (when (and (memq stream '(nil network starttls))
+                 (eq (plist-get props :type) 'tls))
+        (sieve-manage-drop-next-answer))
+      (current-buffer))))
 
 ;; Authenticators
+(defun sieve-sasl-auth (buffer mech)
+  "Login to server using the SASL MECH method."
+  (message "sieve: Authenticating using %s..." mech)
+  (with-current-buffer buffer
+    (let* ((auth-info (auth-source-search :host sieve-manage-server
+                                          :port "sieve"
+                                          :max 1
+                                          :create t))
+           (user-name (or (plist-get (nth 0 auth-info) :user) ""))
+           (user-password (or (plist-get (nth 0 auth-info) :secret) ""))
+           (user-password (if (functionp user-password)
+                              (funcall user-password)
+                            user-password))
+           (client (sasl-make-client (sasl-find-mechanism (list mech))
+                                     user-name "sieve" sieve-manage-server))
+           (sasl-read-passphrase
+            ;; We *need* to copy the password, because sasl will modify it
+            ;; somehow.
+            `(lambda (prompt) ,(copy-sequence user-password)))
+           (step (sasl-next-step client nil))
+           (tag (sieve-manage-send
+                 (concat
+                  "AUTHENTICATE \""
+                  mech
+                  "\""
+                  (and (sasl-step-data step)
+                       (concat
+                        " \""
+                        (base64-encode-string
+                         (sasl-step-data step)
+                         'no-line-break)
+                        "\"")))))
+           data rsp)
+      (catch 'done
+        (while t
+          (setq rsp nil)
+          (goto-char (point-min))
+          (while (null (or (progn
+                             (setq rsp (sieve-manage-is-string))
+                             (if (not (and rsp (looking-at
+                                                sieve-manage-server-eol)))
+                                 (setq rsp nil)
+                               (goto-char (match-end 0))
+                               rsp))
+                           (setq rsp (sieve-manage-is-okno))))
+            (accept-process-output sieve-manage-process 1)
+            (goto-char (point-min)))
+          (sieve-manage-erase)
+          (when (sieve-manage-ok-p rsp)
+            (when (and (cadr rsp)
+                       (string-match "^SASL \"\\([^\"]+\\)\"" (cadr rsp)))
+              (sasl-step-set-data
+               step (base64-decode-string (match-string 1 (cadr rsp)))))
+            (if (and (setq step (sasl-next-step client step))
+                     (setq data (sasl-step-data step)))
+                ;; We got data for server but it's finished
+                (error "Server not ready for SASL data: %s" data)
+              ;; The authentication process is finished.
+              (throw 'done t)))
+          (unless (stringp rsp)
+            (error "Server aborted SASL authentication: %s" (caddr rsp)))
+          (sasl-step-set-data step (base64-decode-string rsp))
+          (setq step (sasl-next-step client step))
+          (sieve-manage-send
+           (if (sasl-step-data step)
+               (concat "\""
+                       (base64-encode-string (sasl-step-data step)
+                                             'no-line-break)
+                       "\"")
+             ""))))
+      (message "sieve: Login using %s...done" mech))))
+
+(defun sieve-manage-cram-md5-p (buffer)
+  (sieve-manage-capability "SASL" "CRAM-MD5" buffer))
+
+(defun sieve-manage-cram-md5-auth (buffer)
+  "Login to managesieve server using the CRAM-MD5 SASL method."
+  (sieve-sasl-auth buffer "CRAM-MD5"))
+
+(defun sieve-manage-digest-md5-p (buffer)
+  (sieve-manage-capability "SASL" "DIGEST-MD5" buffer))
+
+(defun sieve-manage-digest-md5-auth (buffer)
+  "Login to managesieve server using the DIGEST-MD5 SASL method."
+  (sieve-sasl-auth buffer "DIGEST-MD5"))
+
+(defun sieve-manage-scram-md5-p (buffer)
+  (sieve-manage-capability "SASL" "SCRAM-MD5" buffer))
+
+(defun sieve-manage-scram-md5-auth (buffer)
+  "Login to managesieve server using the SCRAM-MD5 SASL method."
+  (sieve-sasl-auth buffer "SCRAM-MD5"))
+
+(defun sieve-manage-ntlm-p (buffer)
+  (sieve-manage-capability "SASL" "NTLM" buffer))
+
+(defun sieve-manage-ntlm-auth (buffer)
+  "Login to managesieve server using the NTLM SASL method."
+  (sieve-sasl-auth buffer "NTLM"))
 
 (defun sieve-manage-plain-p (buffer)
   (sieve-manage-capability "SASL" "PLAIN" buffer))
 
 (defun sieve-manage-plain-auth (buffer)
   "Login to managesieve server using the PLAIN SASL method."
-  (let* ((done (sieve-manage-interactive-login
-               buffer
-               (lambda (user passwd)
-                 (sieve-manage-send (concat "AUTHENTICATE \"PLAIN\" \""
-                                            (base64-encode-string
-                                             (concat (char-to-string 0)
-                                                     user 
-                                                     (char-to-string 0)
-                                                     passwd))
-                                            "\""))
-                 (let ((rsp (sieve-manage-parse-okno)))
-                   (if (sieve-manage-ok-p rsp)
-                       t
-                     (setq reason (cdr-safe rsp))
-                     nil))))))
-    (if done
-       (message "sieve: Authenticating using PLAIN...done")
-      (message "sieve: Authenticating using PLAIN...failed"))))
+  (sieve-sasl-auth buffer "PLAIN"))
 
-(defun sieve-manage-cram-md5-p (buffer)
-  (sieve-manage-capability "SASL" "CRAM-MD5" buffer))
+(defun sieve-manage-login-p (buffer)
+  (sieve-manage-capability "SASL" "LOGIN" buffer))
 
-(defun sieve-manage-cram-md5-auth (buffer)
-  "Login to managesieve server using the CRAM-MD5 SASL method."
-  (message "sieve: Authenticating using CRAM-MD5...")
-  (let* ((done (sieve-manage-interactive-login
-               buffer
-               (lambda (user passwd)
-                 (sieve-manage-send "AUTHENTICATE \"CRAM-MD5\" \"\"")
-                 (sieve-manage-send
-                  (concat
-                   "\""
-                   (base64-encode-string
-                    (concat
-                     user " "
-                     (rfc2104-hash 'md5 64 16 passwd
-                                   (base64-decode-string
-                                    (prog1
-                                        (sieve-manage-parse-string)
-                                      (sieve-manage-erase))))))
-                   "\""))
-                 (let ((rsp (sieve-manage-parse-okno)))
-                   (if (sieve-manage-ok-p rsp)
-                       t
-                     (setq reason (cdr-safe rsp))
-                     nil))))))
-    (if done
-       (message "sieve: Authenticating using CRAM-MD5...done")
-      (message "sieve: Authenticating using CRAM-MD5...failed"))))
+(defun sieve-manage-login-auth (buffer)
+  "Login to managesieve server using the LOGIN SASL method."
+  (sieve-sasl-auth buffer "LOGIN"))
 
 ;; Managesieve API
 
 (defun sieve-manage-open (server &optional port stream auth buffer)
   "Open a network connection to a managesieve SERVER (string).
-Optional variable PORT is port number (integer) on remote server.
-Optional variable STREAM is any of `sieve-manage-streams' (a symbol).
-Optional variable AUTH indicates authenticator to use, see
-`sieve-manage-authenticators' for available authenticators.  If nil, chooses
-the best stream the server is capable of.
-Optional variable BUFFER is buffer (buffer, or string naming buffer)
+Optional argument PORT is port number (integer) on remote server.
+Optional argument STREAM is any of `sieve-manage-streams' (a symbol).
+Optional argument AUTH indicates authenticator to use, see
+`sieve-manage-authenticators' for available authenticators.
+If nil, chooses the best stream the server is capable of.
+Optional argument BUFFER is buffer (buffer, or string naming buffer)
 to work in."
-  (setq buffer (or buffer (format " *sieve* %s:%d" server (or port 2000))))
-  (with-current-buffer (get-buffer-create buffer)
-    (mapcar 'make-variable-buffer-local sieve-manage-local-variables)
-    (sieve-manage-disable-multibyte)
-    (buffer-disable-undo)
-    (setq sieve-manage-server (or server sieve-manage-server))
-    (setq sieve-manage-port (or port sieve-manage-port))
-    (setq sieve-manage-stream (or stream sieve-manage-stream))
+  (setq sieve-manage-port (or port sieve-manage-default-port))
+  (with-current-buffer (or buffer (sieve-manage-make-process-buffer))
+    (setq sieve-manage-server (or server
+                                  sieve-manage-server)
+          sieve-manage-stream (or stream
+                                  sieve-manage-stream
+                                  sieve-manage-default-stream)
+          sieve-manage-auth   (or auth
+                                  sieve-manage-auth))
     (message "sieve: Connecting to %s..." sieve-manage-server)
-    (if (let ((sieve-manage-stream
-              (or sieve-manage-stream sieve-manage-default-stream)))
-         (sieve-manage-open-1 buffer))
-       ;; Choose stream.
-       (let (stream-changed)
-         (message "sieve: Connecting to %s...done" sieve-manage-server)
-         (when (null sieve-manage-stream)
-           (let ((streams sieve-manage-streams))
-             (while (setq stream (pop streams))
-               (if (funcall (nth 1 (assq stream
-                                         sieve-manage-stream-alist)) buffer)
-                   (setq stream-changed
-                         (not (eq (or sieve-manage-stream 
-                                      sieve-manage-default-stream)
-                                  stream))
-                         sieve-manage-stream stream
-                         streams nil)))
-             (unless sieve-manage-stream
-               (error "Couldn't figure out a stream for server"))))
-         (when stream-changed
-           (message "sieve: Reconnecting with stream `%s'..."
-                    sieve-manage-stream)
-           (sieve-manage-close buffer)
-           (if (sieve-manage-open-1 buffer)
-               (message "sieve: Reconnecting with stream `%s'...done"
-                        sieve-manage-stream)
-             (message "sieve: Reconnecting with stream `%s'...failed" 
-                      sieve-manage-stream))
-           (setq sieve-manage-capability nil))
-         (if (sieve-manage-opened buffer)
-             ;; Choose authenticator
-             (when (and (null sieve-manage-auth)
-                        (not (eq sieve-manage-state 'auth)))
-               (let ((auths sieve-manage-authenticators))                    
-                 (while (setq auth (pop auths))
-                   (if (funcall (nth 1 (assq
-                                        auth
-                                        sieve-manage-authenticator-alist))
-                                buffer)
-                       (setq sieve-manage-auth auth
-                             auths nil)))
-                 (unless sieve-manage-auth
-                   (error "Couldn't figure out authenticator for server"))))))
-      (message "sieve: Connecting to %s...failed" sieve-manage-server))
-    (when (sieve-manage-opened buffer)
+    (sieve-manage-open-server sieve-manage-server
+                              sieve-manage-port
+                              sieve-manage-stream
+                              (current-buffer))
+    (when (sieve-manage-opened (current-buffer))
+      ;; Choose authenticator
+      (when (and (null sieve-manage-auth)
+                 (not (eq sieve-manage-state 'auth)))
+        (dolist (auth sieve-manage-authenticators)
+          (when (funcall (nth 1 (assq auth sieve-manage-authenticator-alist))
+                       buffer)
+            (setq sieve-manage-auth auth)
+            (return)))
+        (unless sieve-manage-auth
+          (error "Couldn't figure out authenticator for server")))
       (sieve-manage-erase)
-      buffer)))
+      (current-buffer))))
+
+(defun sieve-manage-authenticate (&optional buffer)
+  "Authenticate on server in BUFFER.
+Return `sieve-manage-state' value."
+  (with-current-buffer (or buffer (current-buffer))
+    (if (eq sieve-manage-state 'nonauth)
+        (when (funcall (nth 2 (assq sieve-manage-auth
+                                    sieve-manage-authenticator-alist))
+                       (current-buffer))
+          (setq sieve-manage-state 'auth))
+      sieve-manage-state)))
 
 (defun sieve-manage-opened (&optional buffer)
   "Return non-nil if connection to managesieve server in BUFFER is open.
@@ -454,32 +410,19 @@ If BUFFER is nil, the current buffer is used."
     (sieve-manage-erase)
     t))
 
-(defun sieve-manage-authenticate (&optional user passwd buffer)
-  "Authenticate to server in BUFFER, using current buffer if nil.
-It uses the authenticator specified when opening the server.  If the
-authenticator requires username/passwords, they are queried from the
-user and optionally stored in the buffer.  If USER and/or PASSWD is
-specified, the user will not be questioned and the username and/or
-password is remembered in the buffer."
-  (with-current-buffer (or buffer (current-buffer))
-    (if (not (eq sieve-manage-state 'nonauth))
-       (eq sieve-manage-state 'auth)
-      (make-variable-buffer-local 'sieve-manage-username)
-      (make-variable-buffer-local 'sieve-manage-password)
-      (if user (setq sieve-manage-username user))
-      (if passwd (setq sieve-manage-password passwd))
-      (if (funcall (nth 2 (assq sieve-manage-auth
-                               sieve-manage-authenticator-alist)) buffer)
-         (setq sieve-manage-state 'auth)))))
-
 (defun sieve-manage-capability (&optional name value buffer)
+  "Check if capability NAME of server BUFFER match VALUE.
+If it does, return the server value of NAME. If not returns nil.
+If VALUE is nil, do not check VALUE and return server value.
+If NAME is nil, return the full server list of capabilities."
   (with-current-buffer (or buffer (current-buffer))
     (if (null name)
        sieve-manage-capability
-      (if (null value)
-         (nth 1 (assoc name sieve-manage-capability))
-       (when (string-match value (nth 1 (assoc name sieve-manage-capability)))
-         (nth 1 (assoc name sieve-manage-capability)))))))
+      (let ((server-value (cadr (assoc name sieve-manage-capability))))
+        (when (or (null value)
+                  (and server-value
+                       (string-match value server-value)))
+          server-value)))))
 
 (defun sieve-manage-listscripts (&optional buffer)
   (with-current-buffer (or buffer (current-buffer))
@@ -491,18 +434,22 @@ password is remembered in the buffer."
     (sieve-manage-send (format "HAVESPACE \"%s\" %s" name size))
     (sieve-manage-parse-okno)))
 
-(eval-and-compile
-  (if (fboundp 'string-bytes)
-      (defalias 'sieve-string-bytes 'string-bytes)
-    (defalias 'sieve-string-bytes 'length)))
-
 (defun sieve-manage-putscript (name content &optional buffer)
   (with-current-buffer (or buffer (current-buffer))
     (sieve-manage-send (format "PUTSCRIPT \"%s\" {%d+}%s%s" name
-                              (sieve-string-bytes content)
+                               ;; Here we assume that the coding-system will
+                               ;; replace each char with a single byte.
+                               ;; This is always the case if `content' is
+                               ;; a unibyte string.
+                              (length content)
                               sieve-manage-client-eol content))
     (sieve-manage-parse-okno)))
 
+(defun sieve-manage-deletescript (name &optional buffer)
+  (with-current-buffer (or buffer (current-buffer))
+    (sieve-manage-send (format "DELETESCRIPT \"%s\"" name))
+    (sieve-manage-parse-okno)))
+
 (defun sieve-manage-getscript (name output-buffer &optional buffer)
   (with-current-buffer (or buffer (current-buffer))
     (sieve-manage-send (format "GETSCRIPT \"%s\"" name))
@@ -519,17 +466,33 @@ password is remembered in the buffer."
 
 ;; Protocol parsing routines
 
+(defun sieve-manage-wait-for-answer ()
+  (let ((pattern "^\\(OK\\|NO\\).*\n")
+        pos)
+    (while (not pos)
+      (setq pos (search-forward-regexp pattern nil t))
+      (goto-char (point-min))
+      (sleep-for 0 50))
+    pos))
+
+(defun sieve-manage-drop-next-answer ()
+  (sieve-manage-wait-for-answer)
+  (sieve-manage-erase))
+
 (defun sieve-manage-ok-p (rsp)
   (string= (downcase (or (car-safe rsp) "")) "ok"))
 
-(defsubst sieve-manage-forward ()
-  (or (eobp) (forward-char)))
-
 (defun sieve-manage-is-okno ()
   (when (looking-at (concat
                     "^\\(OK\\|NO\\)\\( (\\([^)]+\\))\\)?\\( \\(.*\\)\\)?"
                     sieve-manage-server-eol))
-    (list (match-string 1) (match-string 3) (match-string 5))))
+    (let ((status (match-string 1))
+         (resp-code (match-string 3))
+         (response (match-string 5)))
+      (when response
+       (goto-char (match-beginning 5))
+       (setq response (sieve-manage-is-string)))
+      (list status resp-code response))))
 
 (defun sieve-manage-parse-okno ()
   (let (rsp)
@@ -540,28 +503,22 @@ password is remembered in the buffer."
     (sieve-manage-erase)
     rsp))
 
-(defun sieve-manage-parse-capability-1 ()
-  "Accept a managesieve greeting."
-  (let (str)
-    (while (setq str (sieve-manage-is-string))
-      (if (eq (char-after) ? )
-         (progn
-           (sieve-manage-forward)
-           (push (list str (sieve-manage-is-string))
-                 sieve-manage-capability))
-       (push (list str) sieve-manage-capability))
-      (forward-line)))
-  (when (re-search-forward (concat "^OK" sieve-manage-server-eol) nil t)
-    (setq sieve-manage-state 'nonauth)))
-
-(defalias 'sieve-manage-parse-greeting-1 'sieve-manage-parse-capability-1)
+(defun sieve-manage-parse-capability (str)
+  "Parse managesieve capability string `STR'.
+Set variable `sieve-manage-capability' to "
+  (let ((capas (delq nil
+                     (mapcar #'split-string-and-unquote
+                             (split-string str "\n")))))
+    (when (string= "OK" (caar (last capas)))
+      (setq sieve-manage-state 'nonauth))
+    capas))
 
 (defun sieve-manage-is-string ()
   (cond ((looking-at "\"\\([^\"]+\\)\"")
         (prog1
             (match-string 1)
           (goto-char (match-end 0))))
-       ((looking-at (concat "{\\([0-9]+\\)}" sieve-manage-server-eol))
+       ((looking-at (concat "{\\([0-9]+\\+?\\)}" sieve-manage-server-eol))
         (let ((pos (match-end 0))
               (len (string-to-number (match-string 1))))
           (if (< (point-max) (+ pos len))
@@ -608,7 +565,7 @@ password is remembered in the buffer."
   (setq cmdstr (concat cmdstr sieve-manage-client-eol))
   (and sieve-manage-log
        (with-current-buffer (get-buffer-create sieve-manage-log)
-        (sieve-manage-disable-multibyte)
+        (mm-enable-multibyte)
         (buffer-disable-undo)
         (goto-char (point-max))
         (insert cmdstr)))