--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/gnus/pop3.el	Mon Aug 13 08:49:20 2007 +0200
@@ -0,0 +1,430 @@
+;;; pop3.el --- Post Office Protocol (RFC 1460) interface
+
+;; Copyright (C) 1996, Free Software Foundation, Inc.
+
+;; Author: Richard L. Pieri <ratinox@peorth.gweep.net>
+;; Keywords: mail, pop3
+;; Version: 1.3
+
+;; This file is part of GNU Emacs.
+
+;; 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.
+
+;; 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
+;; 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.
+
+;;; Commentary:
+
+;; Most of the standard Post Office Protocol version 3 (RFC 1460) commands
+;; are implemented.  The LIST command has not been implemented due to lack
+;; of actual usefulness.
+;; The optional POP3 command TOP has not been implemented.
+
+;; This program was inspired by Kyle E. Jones's vm-pop program.
+
+;;; Code:
+
+(require 'mail-utils)
+(provide 'pop3)
+
+(eval-and-compile
+  (if (not (fboundp 'md5)) (autoload 'md5 "md5")))
+
+(defvar pop3-maildrop (or user-login-name (getenv "LOGNAME") (getenv "USER") nil)
+  "*POP3 maildrop.")
+(defvar pop3-mailhost (or (getenv "MAILHOST") nil)
+  "*POP3 mailhost.")
+(defvar pop3-port 110
+  "*POP3 port.")
+
+(defvar pop3-password-required t
+  "*Non-nil if a password is required when connecting to POP server.")
+(defvar pop3-password nil
+  "*Password to use when connecting to POP server.")
+
+(defvar pop3-authentication-scheme 'pass
+  "*POP3 authentication scheme.  Defaults to 'pass, for the standard
+USER/PASS authentication.  Other valid values are 'apop.")
+
+(defvar pop3-timestamp nil
+  "Timestamp returned when initially connected to the POP server.
+Used for APOP authentication.")
+
+(defvar pop3-read-point nil)
+(defvar pop3-debug nil)
+
+(defun pop3-movemail (&optional crashbox)
+  "Transfer contents of a maildrop to the specified CRASHBOX."
+  (or crashbox (setq crashbox (expand-file-name "~/.crashbox")))
+  (let* ((process (pop3-open-server pop3-mailhost pop3-port))
+	 (crashbuf (get-buffer-create " *pop3-retr*"))
+	 (n 1)
+	 message-count)
+    ;; for debugging only
+    (if pop3-debug (switch-to-buffer (process-buffer process)))
+    (cond ((equal 'apop pop3-authentication-scheme)
+	   (pop3-apop process pop3-maildrop))
+	  ((equal 'pass pop3-authentication-scheme)
+	   (pop3-user process pop3-maildrop)
+	   (pop3-pass process))
+	  (t (error "Invalid POP3 authentication scheme.")))
+    (setq message-count (car (pop3-stat process)))
+    (while (<= n message-count)
+      (message (format "Retrieving message %d of %d from %s..."
+		       n message-count pop3-mailhost))
+      (pop3-retr process n crashbuf)
+      (save-excursion
+	(set-buffer crashbuf)
+	(append-to-file (point-min) (point-max) crashbox))
+      (pop3-dele process n)
+      (setq n (+ 1 n)))
+    (pop3-quit process)
+    (kill-buffer crashbuf)
+    )
+  )
+
+(defun pop3-open-server (mailhost port)
+  "Open TCP connection to MAILHOST.
+Returns the process associated with the connection."
+  (let ((process-buffer
+	 (get-buffer-create (format "trace of POP session to %s" mailhost)))
+	(process))
+    (save-excursion
+      (set-buffer process-buffer)
+      (erase-buffer))
+    (setq process
+	  (open-network-stream "POP" process-buffer mailhost port))
+    (setq pop3-read-point (point-min))
+    (let ((response (pop3-read-response process t)))
+      (setq pop3-timestamp
+	    (substring response (or (string-match "<" response) 0)
+		       (+ 1 (or (string-match ">" response) -1)))))
+    process
+    ))
+
+;; Support functions
+
+(defun pop3-process-filter (process output)
+  (save-excursion
+    (set-buffer (process-buffer process))
+    (goto-char (point-max))
+    (insert output)))
+
+(defun pop3-send-command (process command)
+    (set-buffer (process-buffer process))
+    (goto-char (point-max))
+;;    (if (= (aref command 0) ?P)
+;;	(insert "PASS <omitted>\r\n")
+;;      (insert command "\r\n"))
+    (setq pop3-read-point (point))
+    (goto-char (point-max))
+    (process-send-string process command)
+    (process-send-string process "\r\n")
+    )
+
+(defun pop3-read-response (process &optional return)
+  "Read the response from the server.
+Return the response string if optional second argument is non-nil."
+  (let ((case-fold-search nil)
+	match-end)
+    (save-excursion
+      (set-buffer (process-buffer process))
+      (goto-char pop3-read-point)
+      (while (not (search-forward "\r\n" nil t))
+	(accept-process-output process)
+	(goto-char pop3-read-point))
+      (setq match-end (point))
+      (goto-char pop3-read-point)
+      (if (looking-at "-ERR")
+	  (error (buffer-substring (point) (- match-end 2)))
+	(if (not (looking-at "+OK"))
+	    (progn (setq pop3-read-point match-end) nil)
+	  (setq pop3-read-point match-end)
+	  (if return
+	      (buffer-substring (point) match-end)
+	    t)
+	  )))))
+
+(defun pop3-string-to-list (string &optional regexp)
+  "Chop up a string into a list."
+  (let ((list)
+	(regexp (or regexp " "))
+	(string (if (string-match "\r" string)
+		    (substring string 0 (match-beginning 0))
+		  string)))
+    (store-match-data nil)
+    (while string
+      (if (string-match regexp string)
+	  (setq list (cons (substring string 0 (- (match-end 0) 1)) list)
+		string (substring string (match-end 0)))
+	(setq list (cons string list)
+	      string nil)))
+    (nreverse list)))
+
+(defvar pop3-read-passwd nil)
+(defun pop3-read-passwd (prompt)
+  (if (not pop3-read-passwd)
+      (if (load "passwd" t)
+	  (setq pop3-read-passwd 'read-passwd)
+	(autoload 'ange-ftp-read-passwd "ange-ftp")
+	(setq pop3-read-passwd 'ange-ftp-read-passwd)))
+  (funcall pop3-read-passwd prompt))
+
+(defun pop3-clean-region (start end)
+  (setq end (set-marker (make-marker) end))
+  (save-excursion
+    (goto-char start)
+    (while (and (< (point) end) (search-forward "\r\n" end t))
+      (replace-match "\n" t t))
+    (goto-char start)
+    (while (and (< (point) end) (re-search-forward "^\\." end t))
+      (replace-match "" t t)
+      (forward-char)))
+  (set-marker end nil))
+
+(defun pop3-munge-message-separator (start end)
+  "Check to see if a message separator exists.  If not, generate one."
+  (save-excursion
+    (save-restriction
+      (narrow-to-region start end)
+      (goto-char (point-min))
+      (if (not (or (looking-at "From .?") ; Unix mail
+		   (looking-at "\001\001\001\001\n") ; MMDF
+		   (looking-at "BABYL OPTIONS:") ; Babyl
+		   ))
+	  (let ((from (mail-strip-quoted-names (mail-fetch-field "From")))
+		(date (pop3-string-to-list (mail-fetch-field "Date")))
+		(From_))
+	    ;; sample date formats I have seen
+	    ;; Date: Tue, 9 Jul 1996 09:04:21 -0400 (EDT)
+	    ;; Date: 08 Jul 1996 23:22:24 -0400
+	    ;; should be
+	    ;; Tue Jul 9 09:04:21 1996
+	    (setq date
+		  (cond ((string-match "[A-Z]" (nth 0 date))
+			 (format "%s %s %s %s %s"
+				 (nth 0 date) (nth 2 date) (nth 1 date)
+				 (nth 4 date) (nth 3 date)))
+			(t
+			 ;; this really needs to be better but I don't feel
+			 ;; like writing a date to day converter.
+			 (format "Sun %s %s %s %s"
+				 (nth 1 date) (nth 0 date)
+				 (nth 3 date) (nth 2 date)))
+			))
+	    (setq From_ (format "From %s  %s\n" from date))
+	    (while (string-match "," From_)
+	      (setq From_ (concat (substring From_ 0 (match-beginning 0))
+				  (substring From_ (match-end 0)))))
+	    (goto-char (point-min))
+	    (insert From_))))))
+
+;; The Command Set
+
+;; AUTHORIZATION STATE
+
+(defun pop3-user (process user)
+  "Send USER information to POP3 server."
+  (pop3-send-command process (format "USER %s" user))
+  (let ((response (pop3-read-response process t)))
+    (if (not (and response (string-match "+OK" response)))
+	(error (format "USER %s not valid." user)))))
+
+(defun pop3-pass (process)
+  "Send authentication information to the server."
+  (let ((pass pop3-password))
+    (if (and pop3-password-required (not pass))
+	(setq pass
+	      (pop3-read-passwd (format "Password for %s: " pop3-maildrop))))
+    (if pass
+	(progn
+	  (pop3-send-command process (format "PASS %s" pass))
+	  (let ((response (pop3-read-response process t)))
+	    (if (not (and response (string-match "+OK" response)))
+		(pop3-quit process)))))
+    ))
+
+(defun pop3-apop (process user)
+  "Send alternate authentication information to the server."
+  (if (not (fboundp 'md5)) (autoload 'md5 "md5"))
+  (let ((pass pop3-password))
+    (if (and pop3-password-required (not pass))
+	(setq pass
+	      (pop3-read-passwd (format "Password for %s: " pop3-maildrop))))
+    (if pass
+	(let ((hash (md5 (concat pop3-timestamp pass))))
+	  (pop3-send-command process (format "APOP %s %s" user hash))
+	  (let ((response (pop3-read-response process t)))
+	    (if (not (and response (string-match "+OK" response)))
+		(pop3-quit process)))))
+    ))
+
+;; TRANSACTION STATE
+
+(defun pop3-stat (process)
+  "Return a list of the number of messages in the maildrop and the size
+of the maildrop."
+  (pop3-send-command process "STAT")
+  (let ((response (pop3-read-response process t)))
+    (list (string-to-int (nth 1 (pop3-string-to-list response)))
+	  (string-to-int (nth 2 (pop3-string-to-list response))))
+    ))
+
+(defun pop3-list (process &optional msg)
+  "Scan listing of available messages.
+This function currently does nothing.")
+
+(defun pop3-retr (process msg crashbuf)
+  "Retrieve message-id MSG from the server and place the contents in
+buffer CRASHBUF."
+  (pop3-send-command process (format "RETR %s" msg))
+  (pop3-read-response process)
+  (let ((start pop3-read-point) end)
+    (save-excursion
+      (set-buffer (process-buffer process))
+      (while (not (re-search-forward "^\\.\r\n" nil t))
+	(accept-process-output process)
+	;; bill@att.com ... to save wear and tear on the heap
+	(if (> (buffer-size)  20000) (sleep-for 1))
+	(if (> (buffer-size)  50000) (sleep-for 1))
+	(if (> (buffer-size) 100000) (sleep-for 1))
+	(if (> (buffer-size) 200000) (sleep-for 1))
+	(if (> (buffer-size) 500000) (sleep-for 1))
+	;; bill@att.com
+	(goto-char start))
+      (setq pop3-read-point (point-marker))
+      (goto-char (match-beginning 0))
+      (setq end (point-marker))
+      (pop3-clean-region start end)
+      (pop3-munge-message-separator start end)
+      (save-excursion
+	(set-buffer crashbuf)
+	(erase-buffer))
+      (copy-to-buffer crashbuf start end)
+      (delete-region start end)
+      )))
+
+(defun pop3-dele (process msg)
+  "Mark message-id MSG as deleted."
+  (pop3-send-command process (format "DELE %s" msg))
+  (pop3-read-response process))
+
+(defun pop3-noop (process msg)
+  "No-operation."
+  (pop3-send-command process "NOOP")
+  (pop3-read-response process))
+
+(defun pop3-last (process)
+  "Return highest accessed message-id number for the session."
+  (pop3-send-command process "LAST")
+  (let ((response (pop3-read-response process t)))
+    (string-to-int (nth 1 (pop3-string-to-list response)))
+    ))
+
+(defun pop3-rset (process)
+  "Remove all delete marks from current maildrop."
+  (pop3-send-command process "RSET")
+  (pop3-read-response process))
+
+;; UPDATE
+
+(defun pop3-quit (process)
+  "Tell server to remove all messages marked as deleted, unlock the
+maildrop, and close the connection."
+  (pop3-send-command process "QUIT")
+  (pop3-read-response process t)
+  (if process
+      (save-excursion
+	(set-buffer (process-buffer process))
+	(goto-char (point-max))
+	(delete-process process))))
+
+;; Summary of POP3 (Post Office Protocol version 3) commands and responses
+
+;;; AUTHORIZATION STATE
+
+;; Initial TCP connection
+;; Arguments: none
+;; Restrictions: none
+;; Possible responses:
+;;  +OK [POP3 server ready]
+
+;; USER name
+;; Arguments: a server specific user-id (required)
+;; Restrictions: authorization state [after unsuccessful USER or PASS
+;; Possible responses:
+;;  +OK [valid user-id]
+;;  -ERR [invalid user-id]
+
+;; PASS string
+;; Arguments: a server/user-id specific password (required)
+;; Restrictions: authorization state, after successful USER
+;; Possible responses:
+;;  +OK [maildrop locked and ready]
+;;  -ERR [invalid password]
+;;  -ERR [unable to lock maildrop]
+
+;;; TRANSACTION STATE
+
+;; STAT
+;; Arguments: none
+;; Restrictions: transaction state
+;; Possible responses:
+;;  +OK nn mm [# of messages, size of maildrop]
+
+;; LIST [msg]
+;; Arguments: a message-id (optional)
+;; Restrictions: transaction state; msg must not be deleted
+;; Possible responses:
+;;  +OK [scan listing follows]
+;;  -ERR [no such message]
+
+;; RETR msg
+;; Arguments: a message-id (required)
+;; Restrictions: transaction state; msg must not be deleted
+;; Possible responses:
+;;  +OK [message contents follow]
+;;  -ERR [no such message]
+
+;; DELE msg
+;; Arguments: a message-id (required)
+;; Restrictions: transaction state; msg must not be deleted
+;; Possible responses:
+;;  +OK [message deleted]
+;;  -ERR [no such message]
+
+;; NOOP
+;; Arguments: none
+;; Restrictions: transaction state
+;; Possible responses:
+;;  +OK
+
+;; LAST
+;; Arguments: none
+;; Restrictions: transaction state
+;; Possible responses:
+;;  +OK nn [highest numbered message accessed]
+
+;; RSET
+;; Arguments: none
+;; Restrictions: transaction state
+;; Possible responses:
+;;  +OK [all delete marks removed]
+
+;;; UPDATE STATE
+
+;; QUIT
+;; Arguments: none
+;; Restrictions: none
+;; Possible responses:
+;;  +OK [TCP connection closed]