Support imapd PREAUTH response.

svn path=/trunk/; revision=2509

3 files changed, 19 insertions, 3 deletions

diff --git a/NEWS b/NEWS
index 28d97a52..640c91fd 100644
--- a/NEWS
+++ b/NEWS
@@ -13,7 +13,9 @@ fetchmail-5.0.5 ():
 * Added Spanish and German descriptions to spec (thanks to Horst von Brand).
 * Moved MIME decoding earlier to avoid messing with header length after
   offsets have been calculated.
-* Make the .fetchmail_pid lockfile with O_ECL.  Duhh...
+* Make the .fetchmail_pid lockfile with O_EXCL.  Duhh...
+* New FAQ item RH on startup failures under Red Hat 6.0.
+* IMAP now skips the authorization step on a PREAUTH response.
 
 There are 258 people on fetchmail-friends and 412 on fetchmail-announce.
 
diff --git a/fetchmail.man b/fetchmail.man
index 3896971c..07a999a9 100644
--- a/fetchmail.man
+++ b/fetchmail.man
@@ -636,6 +636,10 @@ to already have a ticket-granting ticket. You may pass a username different
 from your principal name using the standard \fB--user\fR command or by
 the \fI.fetchmailrc\fR option \fBuser\fR.
 .PP
+If your IMAP daemon returns the PREAUTH response in its greeting line, 
+fetchmail will notice this and skip the normal authentication step.
+This could be useful, e.g. if you start imapd explicitly using ssh.
+.PP
 If you are using POP3, and the server issues a one-time-password
 challenge conforming to RFC1938, \fIfetchmail\fR will use your
 password as a pass phrase to generate the required response. This
diff --git a/imap.c b/imap.c
index 602f504e..491c1b41 100644
--- a/imap.c
+++ b/imap.c
@@ -52,7 +52,7 @@ extern char *strstr();	/* needed on sysV68 R3V7.1. */
 #define IMAP4		0	/* IMAP4 rev 0, RFC1730 */
 #define IMAP4rev1	1	/* IMAP4 rev 1, RFC2060 */
 
-static int count, seen, recent, unseen, deletions, imap_version; 
+static int count, seen, recent, unseen, deletions, imap_version, preauth; 
 static int expunged, expunge_period;
 static char capabilities[MSGBUFSIZE+1];
 
@@ -116,7 +116,14 @@ int imap_ok(int sock, char *argbuf)
 	while (isspace(*cp))
 	    cp++;
 
-	if (strncmp(cp, "OK", 2) == 0)
+	if (strncmp(cp, "PREAUTH", 2) == 0)
+	{
+	    if (argbuf)
+		strcpy(argbuf, cp);
+	    preauth = TRUE;
+	    return(PS_SUCCESS);
+	}
+	else if (strncmp(cp, "OK", 2) == 0)
 	{
 	    if (argbuf)
 		strcpy(argbuf, cp);
@@ -767,6 +774,9 @@ int imap_getauth(int sock, struct query *ctl, char *greeting)
 
     peek_capable = (imap_version >= IMAP4);
 
+    if (preauth)
+	return(PS_SUCCESS);
+
 #if OPIE
     if ((ctl->server.protocol == P_IMAP) && strstr(capabilities, "AUTH=X-OTP"))
     {