--- smtp.el-orig	Thu Oct 28 15:01:07 1999
+++ smtp.el	Thu Oct 28 16:54:56 1999
@@ -91,7 +91,8 @@
      (t
       (error "Cannot generate valid FQDN. Set `smtp-local-domain' correctly.")))))
 
-(defun smtp-via-smtp (sender recipients smtp-text-buffer)
+(defun smtp-via-smtp (sender recipients smtp-text-buffer
+			     &optional auth user passphrase)
   (let ((server (if (functionp smtp-server)
 		    (funcall smtp-server sender recipients)
 		  smtp-server))
@@ -135,11 +136,77 @@
 			  (not (integerp (car response)))
 			  (>= (car response) 400))
 		      (throw 'done (car (cdr response)))))
-	      (let ((extension-lines (cdr (cdr response))))
+	      (let ((extension-lines (cdr (cdr response)))
+		    extension)
 		(while extension-lines
-		  (push (intern (downcase (substring (car extension-lines) 4)))
-			extensions)
+		  (if (string-match
+		       "^auth "
+		       (setq extension
+			     (downcase (substring (car extension-lines) 4))))
+		      (while (string-match "\\([^ ]+\\)" extension (match-end 1))
+			(push (intern (match-string 1 extension)) extensions))
+		    (push (intern extension) extensions))
 		  (setq extension-lines (cdr extension-lines)))))
+
+	    ;; AUTH --- SMTP Service Extension for Authentication (RFC2554)
+	    (when auth
+	      (if (null (memq (intern auth) extensions))
+		  (throw 'done 
+			 (concat "AUTH mechanism " auth " not available")))
+	      
+	      (cond ((string= "cram-md5" auth)
+		     (smtp-send-command process "AUTH CRAM-MD5")
+		     (setq response (smtp-read-response process))
+		     (if (or (null (car response))
+			     (not (integerp (car response)))
+			     (>= (car response) 400))
+			 (throw 'done (car (cdr response))))
+		     (smtp-send-command
+		      process
+		      (base64-encode-string
+		       (concat user " "
+			       (hmac-hex-string
+				(hmac-md5 (base64-decode-string
+					   (substring (car (cdr response)) 4))
+					  passphrase)))))
+		     (setq response (smtp-read-response process))
+		     (if (or (null (car response))
+			     (not (integerp (car response)))
+			     (>= (car response) 400))
+			 (throw 'done (car (cdr response)))))
+
+		    ((string= "plain" auth)
+		     (smtp-send-command
+		      process
+		      (concat "AUTH PLAIN "
+			      (base64-encode-string
+			       (concat "\0" user "\0" passphrase))))
+		     (setq response (smtp-read-response process))
+		     (if (or (null (car response))
+			     (not (integerp (car response)))
+			     (>= (car response) 400))
+			 (throw 'done (car (cdr response)))))
+
+		    ((string= "login" auth)
+		     (smtp-send-command
+		      process
+		      (concat "AUTH LOGIN " user))
+		     (setq response (smtp-read-response process))
+		     (if (or (null (car response))
+			     (not (integerp (car response)))
+			     (>= (car response) 400))
+			 (throw 'done (car (cdr response))))
+		     (smtp-send-command
+		      process
+		      (base64-encode-string passphrase))
+		     (setq response (smtp-read-response process))
+		     (if (or (null (car response))
+			     (not (integerp (car response)))
+			     (>= (car response) 400))
+			 (throw 'done (car (cdr response)))))
+
+		    (t
+		     (throw 'done (concat "AUTH " auth " not supported")))))
 
 	    ;; ONEX --- One message transaction only (sendmail extension?)
 	    (if (or (memq 'onex extensions)