Merge after 4.1.0 import.

1 files changed, 1573 insertions, 986 deletions

diff --git a/contrib/ntp/ntpd/ntp_proto.c b/contrib/ntp/ntpd/ntp_proto.c
index fd59a6b..2374afa 100644
--- a/contrib/ntp/ntpd/ntp_proto.c
+++ b/contrib/ntp/ntpd/ntp_proto.c
@@ -7,15 +7,14 @@
 #include <config.h>
 #endif
 
-#include <stdio.h>
-#include <sys/types.h>
-#include <sys/time.h>
-
 #include "ntpd.h"
 #include "ntp_stdlib.h"
 #include "ntp_unixtime.h"
 #include "ntp_control.h"
 #include "ntp_string.h"
+#include "ntp_crypto.h"
+
+#include <stdio.h>
 
 #if defined(VMS) && defined(VMS_LOCALUNIT)	/*wjm*/
 #include "ntp_refclock.h"
@@ -26,19 +25,22 @@
 #endif
 
 /*
- * System variables are declared here.	See Section 3.2 of the
+ * System variables are declared here. See Section 3.2 of the
  * specification.
  */
 u_char	sys_leap;		/* system leap indicator */
 u_char	sys_stratum;		/* stratum of system */
 s_char	sys_precision;		/* local clock precision */
-double	sys_rootdelay;		/* distance to current sync source */
-double	sys_rootdispersion;	/* dispersion of system clock */
+double	sys_rootdelay;		/* roundtrip delay to primary source */
+double	sys_rootdispersion;	/* dispersion to primary source */
 u_int32 sys_refid;		/* reference source for local clock */
 static	double sys_offset;	/* current local clock offset */
 l_fp	sys_reftime;		/* time we were last updated */
 struct	peer *sys_peer; 	/* our current peer */
+struct	peer *sys_prefer;	/* our cherished peer */
+#ifdef AUTOKEY
 u_long	sys_automax;		/* maximum session key lifetime */
+#endif /* AUTOKEY */
 
 /*
  * Nonspecified system state variables.
@@ -49,10 +51,15 @@ int	sys_authenticate;	/* requre authentication for config */
 l_fp	sys_authdelay;		/* authentication delay */
 static	u_long sys_authdly[2]; 	/* authentication delay shift reg */
 static	u_char leap_consensus;	/* consensus of survivor leap bits */
-static	double sys_maxd; 	/* select error (squares) */
-static	double sys_epsil;	/* system error (squares) */
-u_long	sys_private;		/* private value for session seed */
-int	sys_manycastserver;	/* 1 => respond to manycast client pkts */
+static	double sys_selerr; 	/* select error (squares) */
+static	double sys_syserr;	/* system error (squares) */
+keyid_t	sys_private;		/* private value for session seed */
+int	sys_manycastserver;	/* respond to manycast client pkts */
+u_int sys_survivors;		/* truest of the truechimers */
+int	peer_ntpdate;		/* active peers in ntpdate mode */
+#ifdef AUTOKEY
+char	*sys_hostname;		/* gethostname() name */
+#endif /* AUTOKEY */
 
 /*
  * Statistics counters
@@ -70,12 +77,10 @@ u_long	sys_limitrejected;	/* pkts rejected due to client count per net */
 static	double	root_distance	P((struct peer *));
 static	double	clock_combine	P((struct peer **, int));
 static	void	peer_xmit	P((struct peer *));
-static	void	fast_xmit	P((struct recvbuf *, int, u_long));
+static	void	fast_xmit	P((struct recvbuf *, int, keyid_t, int));
 static	void	clock_update	P((void));
 int	default_get_precision	P((void));
-#ifdef MD5
-static	void	make_keylist	P((struct peer *));
-#endif /* MD5 */
+
 
 /*
  * transmit - Transmit Procedure. See Section 3.4.2 of the
@@ -93,116 +98,173 @@ transmit(
 		u_char oreach;
 
 		/*
-		 * Determine reachability and diddle things if we
-		 * haven't heard from the host for a while. If the peer
-		 * is not configured and not likely to stay around,
-		 * we exhaust it.
+		 * The polling state machine. There are two kinds of
+		 * machines, those that never expect a reply (broadcast
+		 * and manycast server modes) and those that do (all
+		 * other modes). The dance is intricate...
 		 */
+		if (peer->cast_flags & (MDF_BCAST | MDF_MCAST)) {
+
+			/*
+			 * In broadcast mode the poll interval is fixed
+			 * at minpoll and the ttl at ttlmax.
+			 */
+			hpoll = peer->minpoll;
+			peer->ttl = peer->ttlmax;
+#ifdef AUTOKEY
+		} else if (peer->cast_flags & MDF_ACAST) {
+
+			/*
+			 * In manycast mode we start with the minpoll
+			 * interval and ttl. However, the actual poll
+			 * interval is eight times the nominal poll
+			 * interval shown here. If fewer than three
+			 * servers are found, the ttl is increased by
+			 * one and we try again. If this continues to
+			 * the max ttl, the poll interval is bumped by
+			 * one and we try again. If at least three
+			 * servers are found, the poll interval
+			 * increases with the system poll interval to
+			 * the max and we continue indefinately.
+			 * However, about once per day when the
+			 * agreement parameters are refreshed, the
+			 * manycast clients are reset and we start from
+			 * the beginning. This is to catch and clamp the
+			 * ttl to the lowest practical value and avoid
+			 * knocking on spurious doors.
+			 */
+			if (sys_survivors < NTP_MINCLOCK && peer->ttl <
+			    peer->ttlmax)
+				peer->ttl++;
+			hpoll = sys_poll;
+#endif /* AUTOKEY */
+		} else {
+
+			/*
+			 * For associations expecting a reply, the
+			 * watchdog counter is bumped by one if the peer
+			 * has not been heard since the previous poll.
+			 * If the counter reaches the max, the peer is
+			 * demobilized if not configured and just
+			 * cleared if it is, but in this case the poll
+			 * interval is bumped by one.
+			 */
+			if (peer->unreach < NTP_UNREACH) {
+				peer->unreach++;
+			} else if (!(peer->flags & FLAG_CONFIG)) {
+				unpeer(peer);
+				clock_select();
+				return;
+
+			} else {
+				peer_clear(peer);
+				hpoll++;
+			}
+		}
 		oreach = peer->reach;
-		if (oreach & 0x01)
-			peer->valid++;
-		if (oreach & 0x80)
-			peer->valid--;
-		if (!(peer->flags & FLAG_CONFIG) && peer->valid >
-		    NTP_SHIFT / 2 && (peer->reach & 0x80) &&
-		    peer->status < CTL_PST_SEL_SYNCCAND)
-			peer->reach = 0;
 		peer->reach <<= 1;
 		if (peer->reach == 0) {
 
 			/*
-			 * If this is an uncofigured association and
-			 * has become unreachable, demobilize it.
+			 * If this association has become unreachable,
+			 * clear it and raise a trap.
 			 */
 			if (oreach != 0) {
 				report_event(EVNT_UNREACH, peer);
 				peer->timereachable = current_time;
-				peer_clear(peer);
 				if (!(peer->flags & FLAG_CONFIG)) {
 					unpeer(peer);
+					clock_select();
 					return;
+				} else {
+					peer_clear(peer);
+					hpoll = peer->minpoll;
 				}
 			}
-
-			/*
-			 * We would like to respond quickly when the
-			 * peer comes back to life. If the probes since
-			 * becoming unreachable are less than
-			 * NTP_UNREACH, clamp the poll interval to the
-			 * minimum. In order to minimize the network
-			 * traffic, the interval gradually ramps up the
-			 * the maximum after that.
-			 */
-			peer->ppoll = peer->maxpoll;
-			if (peer->unreach < NTP_UNREACH) {
-				if (peer->hmode == MODE_CLIENT)
-					peer->unreach++;
-				hpoll = peer->minpoll;
-			} else {
-				hpoll++;
-			}
-			if (peer->flags & FLAG_BURST)
-				peer->burst = 2;
-
+			if (peer->flags & FLAG_IBURST)
+				peer->burst = NTP_SHIFT;
 		} else {
 
 			/*
-			 * Here the peer is reachable. If there is no
-			 * system peer or if the stratum of the system
-			 * peer is greater than this peer, clamp the
-			 * poll interval to the minimum. If less than
-			 * two samples are in the reachability register,
-			 * reduce the interval; if more than six samples
-			 * are in the register, increase the interval.
+			 * Here the peer is reachable. If it has not
+			 * been heard for three consecutive polls, stuff
+			 * the clock filter. Next, determine the poll
+			 * interval. If the peer is a synchronization
+			 * candidate, use the system poll interval. If
+			 * the peer is not sane, increase it by one. If
+			 * the number of valid updates is not greater
+			 * than half the register size, clamp it to the
+			 * minimum. This is to quickly recover the time
+			 * variables when a noisy peer shows life.
 			 */
-			peer->unreach = 0;
-			if (sys_peer == 0)
-				hpoll = peer->minpoll;
-			else if (sys_peer->stratum > peer->stratum)
-				hpoll = peer->minpoll;
-			if ((peer->reach & 0x03) == 0) {
+			if (!(peer->reach & 0x07)) {
 				clock_filter(peer, 0., 0., MAXDISPERSE);
 				clock_select();
 			}
-			if (peer->valid <= 2)
-				hpoll--;
-			else if (peer->valid >= NTP_SHIFT - 2)
+			if ((peer->stratum > 1 && peer->refid ==
+			    peer->dstadr->sin.sin_addr.s_addr) ||
+			    peer->stratum >= STRATUM_UNSPEC)
 				hpoll++;
+			else
+				hpoll = sys_poll;
 			if (peer->flags & FLAG_BURST)
 				peer->burst = NTP_SHIFT;
 		}
 	} else {
 		peer->burst--;
 		if (peer->burst == 0) {
-			if (peer->flags & FLAG_MCAST2) {
-				peer->flags &= ~FLAG_BURST;
+
+			/*
+			 * If a broadcast client at this point, the
+			 * burst has concluded, so we switch to client
+			 * mode and purge the keylist, since no further
+			 * transmissions will be made.
+			 */
+			if (peer->cast_flags & MDF_BCLNT) {
 				peer->hmode = MODE_BCLIENT;
+#ifdef AUTOKEY
+				key_expire(peer);
+#endif /* AUTOKEY */
 			}
-			clock_select();
 			poll_update(peer, hpoll);
+			clock_select();
+
+			/*
+			 * If ntpdate mode and the clock has not been
+			 * set and all peers have completed the burst,
+			 * we declare a successful failure.
+			 */
+			if (mode_ntpdate) {
+				peer_ntpdate--;
+				if (peer_ntpdate > 0)
+					return;
+				NLOG(NLOG_SYNCEVENT | NLOG_SYSEVENT)
+				    msyslog(LOG_NOTICE,
+				    "no reply; clock not set");
+				printf(
+				    "ntpd: no reply; clock not set\n");
+				exit(0);
+			}
 			return;
+
 		}
 	}
+	peer->outdate = current_time;
+	poll_update(peer, hpoll);
 
 	/*
-	 * We need to be very careful about honking uncivilized time. If
-	 * not operating in broadcast mode, honk in all except broadcast
-	 * client mode. If operating in broadcast mode and synchronized
-	 * to a real source, honk except when the peer is the local-
-	 * clock driver and the prefer flag is not set. In other words,
-	 * in broadcast mode we never honk unless known to be
-	 * synchronized to real time.
+	 * We need to be very careful about honking uncivilized time.
+	 * Never transmit if in broadcast client mode or access denied.
+	 * If in broadcast mode, transmit only if synchronized to a
+	 * valid source. 
 	 */
-	if (peer->hmode != MODE_BROADCAST) {
-		if (peer->hmode != MODE_BCLIENT)
-			peer_xmit(peer);
-	} else if (sys_peer != 0 && sys_leap != LEAP_NOTINSYNC) {
-		if (!(sys_peer->refclktype == REFCLK_LOCALCLOCK &&
-		    !(sys_peer->flags & FLAG_PREFER)))
-			peer_xmit(peer);
+	if (peer->hmode == MODE_BCLIENT || peer->flash & TEST4) {
+		return;
+	} else if (peer->hmode == MODE_BROADCAST) {
+		if (sys_peer == NULL)
+			return;
 	}
-	peer->outdate = current_time;
-	poll_update(peer, hpoll);
+	peer_xmit(peer);
 }
 
 /*
@@ -218,482 +280,552 @@ receive(
 	int hismode;
 	int oflags;
 	int restrict_mask;
-	int has_mac;			/* has MAC field */
-	int authlen;			/* length of MAC field */
+	int has_mac;			/* length of MAC field */
+	int authlen;			/* offset of MAC field */
 	int is_authentic;		/* cryptosum ok */
-	int is_mystic;			/* session key exists */
-	int is_error;			/* parse error */
-/*	u_long pkeyid; */
-	u_long skeyid, tkeyid;
+	keyid_t skeyid;			/* cryptographic keys */
+	struct sockaddr_in *dstadr_sin;	/* active runway */
+#ifdef AUTOKEY
+	keyid_t pkeyid, tkeyid;		/* cryptographic keys */
+#endif /* AUTOKEY */
 	struct peer *peer2;
 	int retcode = AM_NOMATCH;
 
 	/*
-	 * Monitor the packet and get restrictions
+	 * Monitor the packet and get restrictions. Note that the packet
+	 * length for control and private mode packets must be checked
+	 * by the service routines. Note that no statistics counters are
+	 * recorded for restrict violations, since these counters are in
+	 * the restriction routine. Note the careful distinctions here
+	 * between a packet with a format error and a packet that is
+	 * simply discarded without prejudice. Some restrictions have to
+	 * be handled later in order to generate a kiss-of-death packet.
 	 */
 	ntp_monitor(rbufp);
 	restrict_mask = restrictions(&rbufp->recv_srcadr);
 #ifdef DEBUG
-	if (debug > 1)
-		printf("receive: from %s restrict %02x\n",
+	if (debug > 2)
+		printf("receive: at %ld %s<-%s restrict %02x\n",
+		    current_time, ntoa(&rbufp->dstadr->sin),
 		    ntoa(&rbufp->recv_srcadr), restrict_mask);
 #endif
 	if (restrict_mask & RES_IGNORE)
-		return;
-
-	/*
-	 * Discard packets with invalid version number.
-	 */
+		return;				/* no anything */
+	if (!(SRCPORT(&rbufp->recv_srcadr) == NTP_PORT ||
+	    SRCPORT(&rbufp->recv_srcadr) >= IPPORT_RESERVED)) {
+		sys_badlength++;
+		return;				/* invalid port */
+	}
 	pkt = &rbufp->recv_pkt;
-	if (PKT_VERSION(pkt->li_vn_mode) >= NTP_VERSION)
-		sys_newversionpkt++;
-	else if (PKT_VERSION(pkt->li_vn_mode) >= NTP_OLDVERSION)
-		sys_oldversionpkt++;
-	else {
+	if (PKT_VERSION(pkt->li_vn_mode) == NTP_VERSION) {
+		sys_newversionpkt++;		/* new version */
+	} else if (!(restrict_mask & RES_VERSION) &&
+	    PKT_VERSION(pkt->li_vn_mode) >= NTP_OLDVERSION) {
+		sys_oldversionpkt++;		/* old version */
+	} else {
 		sys_unknownversion++;
-		return;
+		return;				/* invalid version */
 	}
-
-	/*
-	 * Restrict control/private mode packets. Note that packet
-	 * length has to be checked in the control/private mode protocol
-	 * module.
-	 */
 	if (PKT_MODE(pkt->li_vn_mode) == MODE_PRIVATE) {
 		if (restrict_mask & RES_NOQUERY)
-		    return;
+			return;			/* no query private */
 		process_private(rbufp, ((restrict_mask &
 		    RES_NOMODIFY) == 0));
 		return;
 	}
 	if (PKT_MODE(pkt->li_vn_mode) == MODE_CONTROL) {
 		if (restrict_mask & RES_NOQUERY)
-		    return;
+			return;			/* no query control */
 		process_control(rbufp, restrict_mask);
 		return;
 	}
+	if (rbufp->recv_length < LEN_PKT_NOMAC) {
+		sys_badlength++;
+		return;				/* runt packet */
+	}
 
 	/*
-	 * Restrict revenue packets.
-	 */
-	if (restrict_mask & RES_DONTSERVE)
-		return;
-
-        /*
-	 * See if we only accept limited number of clients from the net
-	 * this guy is from. Note: the flag is determined dynamically
-	 * within restrictions()
+	 * Validate mode. Note that NTPv1 is no longer supported.
 	 */
-	if (restrict_mask & RES_LIMITED) {
-		sys_limitrejected++;
-                return;
-        }
+	hismode = (int)PKT_MODE(pkt->li_vn_mode);
+	if (hismode == MODE_UNSPEC) {
+		sys_badlength++;
+		return;				/* invalid mode */
+	}
 
 	/*
-	 * If we are not a broadcast client, ignore broadcast packets.
+	 * Discard broadcast packets received on the wildcard interface
+	 * or if not enabled as broadcast client.
 	 */
-	if ((PKT_MODE(pkt->li_vn_mode) == MODE_BROADCAST &&
-	    !sys_bclient))
+	if (PKT_MODE(pkt->li_vn_mode) == MODE_BROADCAST &&
+	    (rbufp->dstadr == any_interface || !sys_bclient))
 		return;
 
 	/*
-	 * This is really awful ugly. We figure out whether an extension
-	 * field is present and then measure the MAC size. If the number
-	 * of words following the packet header is less than or equal to
-	 * 5, no extension field is present and these words constitute
-	 * the MAC. If the number of words is greater than 5, an
-	 * extension field is present and the first word contains the
-	 * length of the extension field and the MAC follows that.
+	 * Parse the extension field if present. We figure out whether
+	 * an extension field is present by measuring the MAC size. If
+	 * the number of words following the packet header is 0 or 1, no
+	 * MAC is present and the packet is not authenticated. If 1, the
+	 * packet is a reply to a previous request that failed to
+	 * authenticate. If 3, the packet is authenticated with DES; if
+	 * 5, the packet is authenticated with MD5. If greater than 5,
+	 * an extension field is present. If 2 or 4, the packet is a
+	 * runt and goes poof! with a brilliant flash.
 	 */
-	has_mac = 0;
-/*	pkeyid = 0; */
-	skeyid = tkeyid = 0;
+	skeyid = 0;
+#ifdef AUTOKEY
+	pkeyid = tkeyid = 0;
+#endif /* AUTOKEY */
 	authlen = LEN_PKT_NOMAC;
-	has_mac = rbufp->recv_length - authlen;
-	if (has_mac <= 5 * sizeof(u_int32)) {
-		skeyid = (u_long)ntohl(pkt->keyid1) & 0xffffffff;
-	} else {
-		authlen += (u_long)ntohl(pkt->keyid1) & 0xffffffff;
-		has_mac = rbufp->recv_length - authlen;
-		if (authlen <= 0) {
+	while ((has_mac = rbufp->recv_length - authlen) > 0) {
+		int temp;
+
+		if (has_mac % 4 != 0 || has_mac < 0) {
 			sys_badlength++;
 			return;
 		}
+		if (has_mac == 1 * 4 || has_mac == 3 * 4 || has_mac ==
+		    MAX_MAC_LEN) {
+			skeyid = ntohl(((u_int32 *)pkt)[authlen / 4]);
+			break;
 
-		/*
-		 * Note that keyid3 is actually the key ident of the
-		 * MAC itself.
-		 */
-/* 		pkeyid = (u_long)ntohl(pkt->keyid2) & 0xffffffff; */
-		skeyid = tkeyid = (u_long)ntohl(pkt->keyid3) &
-		    0xffffffff;
-	}
-
-	/*
-	 * Figure out his mode and validate it.
-	 */
-	hismode = (int)PKT_MODE(pkt->li_vn_mode);
-	if (PKT_VERSION(pkt->li_vn_mode) == NTP_OLDVERSION && hismode ==
-		0) {
-		/*
-		 * Easy.  If it is from the NTP port it is
-		 * a sym act, else client.
-		 */
-		if (SRCPORT(&rbufp->recv_srcadr) == NTP_PORT)
-			hismode = MODE_ACTIVE;
-		else
-			hismode = MODE_CLIENT;
-	} else {
-		if (hismode != MODE_ACTIVE && hismode != MODE_PASSIVE &&
-			hismode != MODE_SERVER && hismode != MODE_CLIENT &&
-			hismode != MODE_BROADCAST)
+		} else if (has_mac > MAX_MAC_LEN) {
+			temp = ntohl(((u_int32 *)pkt)[authlen / 4]) &
+			    0xffff;
+			if (temp < 4 || temp % 4 != 0) {
+				sys_badlength++;
+				return;
+			}
+			authlen += temp;
+		} else {
+			sys_badlength++;
 			return;
+		}
 	}
 
 	/*
-	 * If he included a mac field, decrypt it to see if it is
-	 * authentic.
+	 * We have tossed out as many buggy packets as possible early in
+	 * the game to reduce the exposure to a clogging attack. Now we
+	 * have to burn some cycles to find the association and
+	 * authenticate the packet if required. Note that we burn only
+	 * MD5 or DES cycles, again to reduce exposure. There may be no
+	 * matching association and that's okay.
+	 *
+	 * More on the autokey mambo. Normally the local interface is
+	 * found when the association was mobilized with respect to a
+	 * designated remote address. We assume packets arriving from
+	 * the remote address arrive via this interface and the local
+	 * address used to construct the autokey is the unicast address
+	 * of the interface. However, if the sender is a broadcaster,
+	 * the interface broadcast address is used instead.
+	 * Notwithstanding this technobabble, if the sender is a
+	 * multicaster, the broadcast address is null, so we use the
+	 * unicast address anyway. Don't ask.
 	 */
-	is_authentic = is_mystic = 0;
+	peer = findpeer(&rbufp->recv_srcadr, rbufp->dstadr, rbufp->fd,
+	    hismode, &retcode);
+	is_authentic = 0;
+	dstadr_sin = &rbufp->dstadr->sin;
 	if (has_mac == 0) {
 #ifdef DEBUG
 		if (debug)
-			printf("receive: at %ld from %s mode %d\n",
-				current_time, ntoa(&rbufp->recv_srcadr),
-				hismode);
+			printf("receive: at %ld %s<-%s mode %d code %d\n",
+			    current_time, ntoa(&rbufp->dstadr->sin),
+			    ntoa(&rbufp->recv_srcadr), hismode, retcode);
 #endif
 	} else {
-		is_mystic = authistrusted(skeyid);
-#ifdef MD5
-		if (skeyid > NTP_MAXKEY && !is_mystic) {
-
+#ifdef AUTOKEY
+		/*
+		 * For autokey modes, generate the session key
+		 * and install in the key cache. Use the socket
+		 * broadcast or unicast address as appropriate.
+		 */
+		if (skeyid > NTP_MAXKEY) {
+		
 			/*
-			 * For multicast mode, generate the session key
-			 * and install in the key cache. For client
-			 * mode, generate the session key for the
-			 * unicast address. For server mode, the session
-			 * key should already be in the key cache, since
-			 * it was generated when the last request was
-			 * sent.
+			 * More on the autokey dance (AKD). A cookie is
+			 * constructed from public and private values.
+			 * For broadcast packets, the cookie is public
+			 * (zero). For packets that match no
+			 * association, the cookie is hashed from the
+			 * addresses and private value. For server
+			 * packets, the cookie was previously obtained
+			 * from the server. For symmetric modes, the
+			 * cookie was previously constructed using an
+			 * agreement protocol; however, should PKI be
+			 * unavailable, we construct a fake agreement as
+			 * the EXOR of the peer and host cookies.
+			 *
+			 * hismode	ephemeral	persistent
+			 * =======================================
+			 * active	0		cookie#
+			 * passive	0%		cookie#
+			 * client	sys cookie	0%
+			 * server	0%		sys cookie
+			 * broadcast	0		0
+			 *
+			 * # if unsync, 0
+			 * % can't happen
 			 */
 			if (hismode == MODE_BROADCAST) {
+
+				/*
+				 * For broadcaster, use the interface
+				 * broadcast address when available;
+				 * otherwise, use the unicast address
+				 * found when the association was
+				 * mobilized.
+				 */
+				pkeyid = 0;
+				if (rbufp->dstadr->bcast.sin_addr.s_addr
+				    != 0)
+					dstadr_sin =
+					    &rbufp->dstadr->bcast;
+			} else if (peer == NULL) {
+				pkeyid = session_key(
+				    &rbufp->recv_srcadr, dstadr_sin, 0,
+				    sys_private, 0);
+			} else {
+				pkeyid = peer->pcookie.key;
+			}
+
+			/*
+			 * The session key includes both the public
+			 * values and cookie. In case of an extension
+			 * field, the cookie used for authentication
+			 * purposes is zero. Note the hash is saved for
+			 * use later in the autokey mambo.
+			 */
+			if (authlen > LEN_PKT_NOMAC && pkeyid != 0) {
+				session_key(&rbufp->recv_srcadr,
+				    dstadr_sin, skeyid, 0, 2);
 				tkeyid = session_key(
-					ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr),
-					ntohl(rbufp->dstadr->bcast.sin_addr.s_addr),
-					skeyid, (u_long)(4 * (1 << pkt->ppoll)));
-			} else if (hismode != MODE_SERVER) {
+				    &rbufp->recv_srcadr, dstadr_sin,
+				    skeyid, pkeyid, 0);
+			} else {
 				tkeyid = session_key(
-					ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr),
-					ntohl(rbufp->dstadr->sin.sin_addr.s_addr),
-					skeyid, (u_long)(4 * (1 << pkt->ppoll)));
+				    &rbufp->recv_srcadr, dstadr_sin,
+				    skeyid, pkeyid, 2);
 			}
 
 		}
-#endif /* MD5 */
+#endif /* AUTOKEY */
 
 		/*
 		 * Compute the cryptosum. Note a clogging attack may
-		 * succceed in bloating the key cache.
+		 * succeed in bloating the key cache. If an autokey,
+		 * purge it immediately, since we won't be needing it
+		 * again.
 		 */
 		if (authdecrypt(skeyid, (u_int32 *)pkt, authlen,
 		    has_mac))
 			is_authentic = 1;
 		else
 			sys_badauth++;
+#ifdef AUTOKEY
+		if (skeyid > NTP_MAXKEY)
+			authtrust(skeyid, 0);
+#endif /* AUTOKEY */
 #ifdef DEBUG
 		if (debug)
 			printf(
-				"receive: at %ld %s mode %d keyid %08lx mac %d auth %d\n",
-				current_time, ntoa(&rbufp->recv_srcadr),
-				hismode, skeyid, has_mac, is_authentic);
+			    "receive: at %ld %s<-%s mode %d code %d keyid %08x len %d mac %d auth %d\n",
+			    current_time, ntoa(dstadr_sin),
+			    ntoa(&rbufp->recv_srcadr), hismode, retcode,
+			    skeyid, authlen, has_mac,
+			    is_authentic);
 #endif
 	}
 
 	/*
-	 * Find the peer.  This will return a null if this guy isn't in
-	 * the database.
+	 * The association matching rules are implemented by a set of
+	 * routines and a table in ntp_peer.c. A packet matching an
+	 * association is processed by that association. If not and
+	 * certain conditions prevail, then an ephemeral association is
+	 * mobilized: a broadcast packet mobilizes a broadcast client
+	 * aassociation; a server packet mobilizes a client association;
+	 * a symmetric active packet mobilizes a symmetric passive
+	 * association. And, the adventure continues...
 	 */
-	peer = findpeer(&rbufp->recv_srcadr, rbufp->dstadr, rbufp->fd,
-		hismode, &retcode);
-	/*
-	 * The new association matching rules are driven by a table
-	 * specified in ntp.h. We have replaced the *default* behaviour
-	 * of replying to bogus packets in server mode in this version.
-	 * A packet must now match an association in order to be
-	 * processed. In the event that no association exists, then an
-	 * association is mobilized if need be. Two different
-	 * associations can be mobilized a) passive associations b)
-	 * client associations due to broadcasts or manycasts.
-	 */
-	is_error = 0;
 	switch (retcode) {
 	case AM_FXMIT:
 
 		/*
-		 * If the client is configured purely as a broadcast
-		 * client and not as an manycast server, it has no
-		 * business being a server. Simply go home. Otherwise,
-		 * send a MODE_SERVER response and go home. Note that we
-		 * don't do a authentication check here, since we can't
-		 * set the system clock; but, we do set the key ID to
-		 * zero to tell the caller about this.
+		 * This is a client mode packet not matching a known
+		 * association. If from a manycast client we run a few
+		 * sanity checks before deciding to send a unicast
+		 * server response. Otherwise, it must be a client
+		 * request, so send a server response and go home.
 		 */
-		if (!sys_bclient || sys_manycastserver) {
-			if (is_authentic)
-				fast_xmit(rbufp, MODE_SERVER, skeyid);
-			else
-				fast_xmit(rbufp, MODE_SERVER, 0);
+		if (sys_manycastserver && (rbufp->dstadr->flags &
+		    INT_MULTICAST)) {
+	
+			/*
+			 * We are picky about responding to a
+			 * manycaster. There is no reason to respond to
+			 * a request if our time is worse than the
+			 * manycaster. We certainly don't reply if not
+			 * synchronized to proventic time.
+			 */
+			if (sys_peer == NULL)
+				return;
+
+			/*
+			 * We don't reply if the our stratum is greater
+			 * than the manycaster.
+			 */ 
+			if (PKT_TO_STRATUM(pkt->stratum) < sys_stratum)
+				return;
 		}
 
 		/*
-		 * We can't get here if an association is mobilized, so
-		 * just toss the key, if appropriate.
+		 * Note that we don't require an authentication check
+		 * here, since we can't set the system clock; but, we do
+		 * set the key ID to zero to tell the caller about this.
 		 */
-		if (!is_mystic && skeyid > NTP_MAXKEY)
-			authtrust(skeyid, 0);
-			return;
+		if (is_authentic)
+			fast_xmit(rbufp, MODE_SERVER, skeyid,
+			    restrict_mask);
+		else
+			fast_xmit(rbufp, MODE_SERVER, 0, restrict_mask);
+		return;
 
 	case AM_MANYCAST:
 
 		/*
-		 * This could be in response to a multicast packet sent
-		 * by the "manycast" mode association. Find peer based
-		 * on the originate timestamp in the packet. Note that
-		 * we don't mobilize a new association, unless the
-		 * packet is properly authenticated. The response must
-		 * be properly authenticated and it's darn funny of the
-		 * manycaster isn't around now. 
+		 * This is a server mode packet returned in response to
+		 * a client mode packet sent to a multicast group
+		 * address. The originate timestamp is a good nonce to
+		 * reliably associate the reply with what was sent. If
+		 * there is no match, that's curious and could be an
+		 * intruder attempting to clog, so we just ignore it.
+		 *
+		 * First, make sure the packet is authentic. If so and
+		 * the manycast association is found, we mobilize a
+		 * client mode association, copy pertinent variables
+		 * from the manycast to the client mode association and
+		 * wind up the spring.
+		 *
+		 * There is an implosion hazard at the manycast client,
+		 * since the manycast servers send the server packet
+		 * immediately.
 		 */
-		if ((sys_authenticate && !is_authentic)) {
-			is_error = 1;
-			break;
-		}
-		peer2 = (struct peer *)findmanycastpeer(&pkt->org);
-		if (peer2 == 0) {
-			is_error = 1;
-			break;
-		}
+		if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED |
+		    RES_NOPEER)) || (sys_authenticate &&
+		    !is_authentic))
+			return;
+
+		peer2 = findmanycastpeer(rbufp);
+		if (peer2 == 0)
+			return;
 
-		/*
-		 * Create a new association and copy the peer variables
-		 * to it. If something goes wrong, carefully pry the new
-		 * association away and return its marbles to the candy
-		 * store.
-		*/
 		peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr,
 		    MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode),
-		    NTP_MINDPOLL, NTP_MAXDPOLL, 0, skeyid);
-		if (peer == 0) {
-			is_error = 1;
-			break;
-		}
-		peer_config_manycast(peer2, peer);
-		break;
-
-	case AM_ERR:
-
-		/*
-		 * Something bad happened. Dirty floor will be mopped by
-		 * the code at the end of this adventure.
-		 */
-		is_error = 1;
+		    sys_minpoll, NTP_MAXDPOLL, FLAG_IBURST |
+		    (peer2->flags & (FLAG_AUTHENABLE | FLAG_SKEY)),
+		    MDF_UCAST, 0, skeyid);
+		if (peer == NULL)
+			return;
 		break;
 
 	case AM_NEWPASS:
 
 		/*
-		 * Okay, we're going to keep him around.  Allocate him
-		 * some memory. But, don't do that unless the packet is
-		 * properly authenticated.
+		 * This is the first packet received from a symmetric
+		 * active peer. First, make sure the packet is
+		 * authentic. If so, mobilize a symmetric passive
+		 * association.
 		 */
-		if ((sys_authenticate && !is_authentic)) {
-			is_error = 1;
-	    		break;
+		if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED |
+		    RES_NOPEER)) || (sys_authenticate &&
+		    !is_authentic)) {
+			fast_xmit(rbufp, MODE_PASSIVE, 0,
+			    restrict_mask);
+			return;
 		}
 		peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr,
 		    MODE_PASSIVE, PKT_VERSION(pkt->li_vn_mode),
-	 	    NTP_MINDPOLL, NTP_MAXDPOLL, 0, skeyid);
+	 	    sys_minpoll, NTP_MAXDPOLL, sys_authenticate ?
+		    FLAG_AUTHENABLE : 0, MDF_UCAST, 0, skeyid);
+		if (peer == NULL)
+			return;
 		break;
 
 	case AM_NEWBCL:
 
 		/*
-		 * Broadcast client being set up now. Do this only if
-		 * the packet is properly authenticated.
+		 * This is the first packet received from a broadcast
+		 * server. First, make sure the packet is authentic, not
+		 * restricted and that we are a broadcast or multicast
+		 * client. If so, mobilize a broadcast client
+		 * association.
 		 */
-		if ((restrict_mask & RES_NOPEER) || !sys_bclient ||
-		    (sys_authenticate && !is_authentic)) {
-			is_error = 1;
-			break;
-		}
+		if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED |
+		    RES_NOPEER)) || (sys_authenticate &&
+		    !is_authentic) || !sys_bclient)
+			return;
+
 		peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr,
-		    MODE_MCLIENT, PKT_VERSION(pkt->li_vn_mode),
-		    NTP_MINDPOLL, NTP_MAXDPOLL, 0, skeyid);
-		if (peer == 0)
-			break;
-		peer->flags |= FLAG_MCAST1 | FLAG_MCAST2 | FLAG_BURST;
-		peer->hmode = MODE_CLIENT;
-		break;
+		    MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode),
+		    sys_minpoll, NTP_MAXDPOLL, FLAG_MCAST |
+		    FLAG_IBURST | (sys_authenticate ?
+		    FLAG_AUTHENABLE : 0), MDF_BCLNT, 0, skeyid);
+#ifdef AUTOKEY
+#ifdef PUBKEY
+		if (peer == NULL)
+			return;
+		if (peer->flags & FLAG_SKEY)
+			crypto_recv(peer, rbufp);
+#endif /* PUBKEY */
+#endif /* AUTOKEY */
+		return;
 
 	case AM_POSSBCL:
 	case AM_PROCPKT:
 
 		/*
-		 * It seems like it is okay to process the packet now
+		 * Happiness and nothing broke. Earn some revenue.
 		 */
 		break;
 
 	default:
 
 		/*
-		 * shouldn't be getting here, but simply return anyway!
+		 * Invalid mode combination. Leave the island
+		 * immediately.
 		 */
-		is_error = 1;
-	}
-	if (is_error) {
-
-		/*
-		 * Error stub. If we get here, something broke. We
-		 * scuttle the autokey if necessary and sink the ship.
-		 * This can occur only upon mobilization, so we can
-		 * throw the structure away without fear of breaking
-		 * anything.
-		 */
-		if (!is_mystic && skeyid > NTP_MAXKEY)
-			authtrust(skeyid, 0);
-		if (peer != 0)
-			if (!(peer->flags & FLAG_CONFIG))
-				unpeer(peer);
 #ifdef DEBUG
 		if (debug)
-			printf("match error code %d assoc %d\n",
-			    retcode, peer_associations);
+			printf("receive: bad protocol %d\n", retcode);
 #endif
 		return;
 	}
 
 	/*
-	 * If the peer isn't configured, set his keyid and authenable
-	 * status based on the packet.
+	 * If the peer isn't configured, set his authenable and autokey
+	 * status based on the packet. Once the status is set, it can't
+	 * be unset. It seems like a silly idea to do this here, rather
+	 * in the configuration routine, but in some goofy cases the
+	 * first packet sent cannot be authenticated and we need a way
+	 * for the dude to change his mind.
 	 */
 	oflags = peer->flags;
 	peer->timereceived = current_time;
+	peer->received++;
 	if (!(peer->flags & FLAG_CONFIG) && has_mac) {
 		peer->flags |= FLAG_AUTHENABLE;
-		if (skeyid > NTP_MAXKEY) {
-			if (peer->flags & FLAG_MCAST2)
-				peer->keyid = skeyid;
-			else
-				peer->flags |= FLAG_SKEY;
-		}
+#ifdef AUTOKEY
+		if (skeyid > NTP_MAXKEY)
+			peer->flags |= FLAG_SKEY;
+#endif /* AUTOKEY */
 	}
 
 	/*
-	 * Determine if this guy is basically trustable. If not, flush
-	 * the bugger. If this is the first packet that is
-	 * authenticated, flush the clock filter. This is to foil
-	 * clogging attacks that might starve the poor dear.
+	 * A valid packet must be from an authentic and allowed source.
+	 * All packets must pass the authentication allowed tests.
+	 * Autokey authenticated packets must pass additional tests and
+	 * public-key authenticated packets must have the credentials
+	 * verified. If all tests are passed, the packet is forwarded
+	 * for processing. If not, the packet is discarded and the
+	 * association demobilized if appropriate.
 	 */
 	peer->flash = 0;
-	if (is_authentic)
+	if (is_authentic) {
 		peer->flags |= FLAG_AUTHENTIC;
-	else
+	} else {
 		peer->flags &= ~FLAG_AUTHENTIC;
-	if (peer->hmode == MODE_BROADCAST && (restrict_mask &
-	    RES_DONTTRUST))
-		peer->flash |= TEST10;		/* access denied */
+	}
+	if (peer->hmode == MODE_BROADCAST &&
+	    (restrict_mask & RES_DONTTRUST))	/* test 4 */
+		peer->flash |= TEST4;		/* access denied */
 	if (peer->flags & FLAG_AUTHENABLE) {
-		if (!(peer->flags & FLAG_AUTHENTIC))
+		if (!(peer->flags & FLAG_AUTHENTIC)) /* test 5 */
 			peer->flash |= TEST5;	/* auth failed */
-		else if (skeyid == 0)
-			peer->flash |= TEST9;	/* peer not auth */
-		else if (!(oflags & FLAG_AUTHENABLE)) {
-			peer_clear(peer);
+		else if (!(oflags & FLAG_AUTHENABLE))
 			report_event(EVNT_PEERAUTH, peer);
-		}
 	}
-	if ((peer->flash & ~(u_int)TEST9) != 0) {
-
-		/*
-		 * The packet is bogus, so we throw it away before
-		 * becoming a denial-of-service hazard. We don't throw
-		 * the current association away if it is configured or
-		 * if it has prior reachable friends.
-		 */
-		if (!is_mystic && skeyid > NTP_MAXKEY)
-			authtrust(skeyid, 0);
-		if (!(peer->flags & FLAG_CONFIG) && peer->reach == 0)
-			unpeer(peer);
+	if (peer->flash) {
 #ifdef DEBUG
 		if (debug)
-			printf(
-			    "invalid packet 0x%02x code %d assoc %d\n",
-			    peer->flash, retcode, peer_associations);
+			printf("receive: bad auth %03x\n", peer->flash);
 #endif
 		return;
 	}
 
-#ifdef MD5
+#ifdef AUTOKEY
 	/*
-	 * The autokey dance. The cha-cha requires that the hash of the
-	 * current session key matches the previous key identifier.
-	 * Heaps of trouble if the steps falter.
+	 * More autokey dance. The rules of the cha-cha are as follows:
+	 *
+	 * 1. If there is no key or the key is not auto, do nothing.
+	 *
+	 * 2. If an extension field contains a verified signature, it is
+	 *    self-authenticated and we sit the dance.
+	 *
+	 * 3. If this is a server reply, check only to see that the
+	 *    transmitted key ID matches the received key ID.
+	 *
+	 * 4. Check to see that one or more hashes of the current key ID
+	 *    matches the previous key ID or ultimate original key ID
+	 *    obtained from the broadcaster or symmetric peer. If no
+	 *    match, sit the dance and wait for timeout.
 	 */
-	if (skeyid > NTP_MAXKEY) {
-		int i;
-
-		/*
-		 * In the case of a new autokey, verify the hash matches
-		 * one of the previous four hashes. If not, raise the
-		 * authentication flasher and hope the next one works.
-		 */
+	if (peer->flags & FLAG_SKEY) {
+		peer->flash |= TEST10;
+		crypto_recv(peer, rbufp);
+		poll_update(peer, peer->hpoll);
 		if (hismode == MODE_SERVER) {
-			peer->pkeyid = peer->keyid;
-		} else if (peer->flags & FLAG_MCAST2) {
-			if (peer->pkeyid > NTP_MAXKEY)
-				authtrust(peer->pkeyid, 0);
-			for (i = 0; i < 4 && tkeyid != peer->pkeyid;
-			    i++) {
-				tkeyid = session_key(
-					ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr),
-					ntohl(rbufp->dstadr->bcast.sin_addr.s_addr),
-					tkeyid, 0);
-			}
+			if (skeyid == peer->keyid)
+				peer->flash &= ~TEST10;
+		} else if (!peer->flash & TEST10) {
+			peer->pkeyid = skeyid;
 		} else {
-			if (peer->pkeyid > NTP_MAXKEY)
-				authtrust(peer->pkeyid, 0);
-			for (i = 0; i < 4 && tkeyid != peer->pkeyid;
-			    i++) {
+			int i;
+
+			for (i = 0; ; i++) {
+				if (tkeyid == peer->pkeyid ||
+				    tkeyid == peer->recauto.key) {
+					peer->flash &= ~TEST10;
+					peer->pkeyid = skeyid;
+					break;
+				}
+				if (i > peer->recauto.seq)
+					break;
 				tkeyid = session_key(
-				    ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr),
-				    ntohl(rbufp->dstadr->sin.sin_addr.s_addr),
-				    tkeyid, 0);
+				    &rbufp->recv_srcadr, dstadr_sin,
+				    tkeyid, pkeyid, 0);
 			}
 		}
-#ifdef XXX /* temp until certificate code is mplemented */
-		if (tkeyid != peer->pkeyid)
-			peer->flash |= TEST9;	/* peer not authentic */
+#ifdef PUBKEY
+
+		/*
+		 * This is delicious. Ordinarily, we kick out all errors
+		 * at this point; however, in symmetric mode and just
+		 * warming up, an unsynchronized peer must inject the
+		 * timestamps, even if it fails further up the road. So,
+		 * let the dude by here, but only if the jerk is not yet
+		 * reachable. After that, he's on his own.
+		 */
+		if (!(peer->flags & FLAG_PROVEN))
+			peer->flash |= TEST11;
+		if (peer->flash && peer->reach) {
+#ifdef DEBUG
+			if (debug)
+				printf("packet: bad autokey %03x\n",
+				    peer->flash);
 #endif
-		peer->pkeyid = skeyid;
+			return;
+		}
+#endif /* PUBKEY */
 	}
-#endif /* MD5 */
+#endif /* AUTOKEY */
 
 	/*
-	 * Gawdz, it's come to this. Process the dang packet. If
-	 * something breaks and the association doesn't deserve to live,
-	 * toss it. Be careful in active mode and return a packet
-	 * anyway.
+	 * We have survived the gaunt. Forward to the packet routine. If
+	 * a symmetric passive association has been mobilized and the
+	 * association doesn't deserve to live, it will die in the
+	 * transmit routine if not reachable after timeout.
 	 */
-	process_packet(peer, pkt, &(rbufp->recv_time));
-	if (!(peer->flags & FLAG_CONFIG) && peer->reach == 0) {
-		if (peer->hmode == MODE_PASSIVE) {
-			if (is_authentic)
-				fast_xmit(rbufp, MODE_PASSIVE, skeyid);
-			else
-				fast_xmit(rbufp, MODE_PASSIVE, 0);
-		}
-		unpeer(peer);
-	}
+	process_packet(peer, pkt, &rbufp->recv_time);
 }
 
 
@@ -703,7 +835,7 @@ receive(
  *	reasonable expectation that we will be having a long term
  *	relationship with this host.
  */
-int
+void
 process_packet(
 	register struct peer *peer,
 	register struct pkt *pkt,
@@ -715,10 +847,13 @@ process_packet(
 	double dtemp;
 	l_fp p_rec, p_xmt, p_org, p_reftime;
 	l_fp ci;
-	int pmode;
+	int pmode, pleap, pstratum;
 
 	/*
-	 * Swap header fields and keep the books.
+	 * Swap header fields and keep the books. The books amount to
+	 * the receive timestamp and poll interval in the header. We
+	 * need these even if there are other problems in order to crank
+	 * up the state machine.
 	 */
 	sys_processed++;
 	peer->processed++;
@@ -731,84 +866,115 @@ process_packet(
 		NTOHL_FP(&pkt->org, &p_org);
 	else
 		p_org = peer->rec;
-	peer->rec = *recv_ts;
-	peer->ppoll = pkt->ppoll;
-	pmode = PKT_MODE(pkt->li_vn_mode);
 
 	/*
-	 * Test for old or duplicate packets (tests 1 through 3).
+	 * Test for old, duplicate or unsynch packets (tests 1-3).
 	 */
+	peer->rec = *recv_ts;
+	pmode = PKT_MODE(pkt->li_vn_mode);
+	pleap = PKT_LEAP(pkt->li_vn_mode);
+	pstratum = PKT_TO_STRATUM(pkt->stratum);
 	if (L_ISHIS(&peer->org, &p_xmt))	/* count old packets */
 		peer->oldpkt++;
-	if (L_ISEQU(&peer->org, &p_xmt))	/* test 1 */
-		peer->flash |= TEST1;		/* duplicate packet */
-	if (PKT_MODE(pkt->li_vn_mode) != MODE_BROADCAST) {
-		if (!L_ISEQU(&peer->xmt, &p_org)) { /* test 2 */
-			peer->bogusorg++;
-			peer->flash |= TEST2;	/* bogus packet */
-		}
-		if (L_ISZERO(&p_rec) || L_ISZERO(&p_org))
-			peer->flash |= TEST3;	/* unsynchronized */
-	} else {
-		if (L_ISZERO(&p_org))
-			peer->flash |= TEST3;	/* unsynchronized */
+	if (L_ISEQU(&peer->org, &p_xmt))	/* 1 */
+		peer->flash |= TEST1;		/* dupe */
+	if (pmode != MODE_BROADCAST) {
+		if (!L_ISEQU(&peer->xmt, &p_org)) /* 2 */
+			peer->flash |= TEST2;	/* bogus */
+		if (L_ISZERO(&p_rec) || L_ISZERO(&p_org)) /* test 3 */
+			peer->flash |= TEST3;	/* unsynch */
 	}
+	if (L_ISZERO(&p_xmt))			/* 3 */
+		peer->flash |= TEST3;		/* unsynch */
 	peer->org = p_xmt;
 
 	/*
-	 * Test for valid header (tests 5 through 10)
+	 * If tests 1-3 fail, the packet is discarded leaving only the
+	 * receive and origin timestamps and poll interval, which is
+	 * enough to get the protocol started.
+	 */
+	if (peer->flash) {
+#ifdef DEBUG
+		if (debug)
+			printf("packet: bad data %03x\n",
+			    peer->flash);
+#endif
+		return;
+	}
+
+	/*
+	 * A kiss-of-death (kod) packet is returned by a server in case
+	 * the client is denied access. It consists of the client
+	 * request packet with the leap bits indicating never
+	 * synchronized, stratum zero and reference ID field the ASCII
+	 * string "DENY". If the packet originate timestamp matches the
+	 * association transmit timestamp the kod is legitimate. If the
+	 * peer leap bits indicate never synchronized, this must be
+	 * access deny and the association is disabled; otherwise this
+	 * must be a limit reject. In either case a naughty message is
+	 * forced to the system log.
+	 */
+	if (pleap == LEAP_NOTINSYNC && pstratum >= STRATUM_UNSPEC &&
+	    memcmp(&pkt->refid, "DENY", 4) == 0) {
+		if (peer->leap == LEAP_NOTINSYNC) {
+			peer->stratum = STRATUM_UNSPEC;
+			peer->flash |= TEST4;
+			memcpy(&peer->refid, &pkt->refid, 4);
+			msyslog(LOG_INFO, "access denied");
+		} else {
+			msyslog(LOG_INFO, "limit reject");
+		}
+		return;
+	}
+
+	/*
+	 * Test for valid peer data (tests 6-8)
 	 */
 	ci = p_xmt;
 	L_SUB(&ci, &p_reftime);
 	LFPTOD(&ci, dtemp);
-	if (PKT_LEAP(pkt->li_vn_mode) == LEAP_NOTINSYNC || /* test 6 */
-	    PKT_TO_STRATUM(pkt->stratum) >= NTP_MAXSTRATUM ||
-	    dtemp < 0)
-		peer->flash |= TEST6;	/* peer clock unsynchronized */
-	if (!(peer->flags & FLAG_CONFIG) && sys_peer != 0) { /* test 7 */
-		if (PKT_TO_STRATUM(pkt->stratum) > sys_stratum) {
-			peer->flash |= TEST7; /* peer stratum too high */
+	if (pleap == LEAP_NOTINSYNC ||		/* 6 */
+	    pstratum >= STRATUM_UNSPEC || dtemp < 0)
+		peer->flash |= TEST6;		/* bad synch */
+	if (!(peer->flags & FLAG_CONFIG) && sys_peer != NULL) { /* 7 */
+		if (pstratum > sys_stratum && pmode != MODE_ACTIVE) {
+			peer->flash |= TEST7;	/* bad stratum */
 			sys_badstratum++;
 		}
 	}
-	if (fabs(p_del) >= MAXDISPERSE	/* test 8 */
-	    || p_disp >= MAXDISPERSE)
-		peer->flash |= TEST8;	/* delay/dispersion too high */
-
-	/*
-	 * If the packet header is invalid (tests 5 through 10), exit.
-	 * XXX we let TEST9 sneak by until the certificate code is
-	 * implemented, but only to mobilize the association.
-	 */
-	if (peer->flash & (TEST5 | TEST6 | TEST7 | TEST8 | TEST10)) {
+	if (p_del < 0 || p_disp < 0 || p_del /	/* 8 */
+	    2 + p_disp >= MAXDISPERSE)
+		peer->flash |= TEST8;		/* bad peer distance */
+	if (peer->flash) {
 #ifdef DEBUG
 		if (debug)
-			printf(
-			    "invalid packet header 0x%02x mode %d\n",
-			    peer->flash, pmode);
+			printf("packet: bad header %03x\n",
+			    peer->flash);
 #endif
-		return (0);
+		return;
 	}
 
 	/*
-	 * Valid header; update our state.
+	 * The header is valid. Capture the remaining header values and
+	 * mark as reachable.
 	 */
-	record_raw_stats(&peer->srcadr, &peer->dstadr->sin,
-	    &p_org, &p_rec, &p_xmt, &peer->rec);
-
-	peer->leap = PKT_LEAP(pkt->li_vn_mode);
-	peer->pmode = pmode;		/* unspec */
-	peer->stratum = PKT_TO_STRATUM(pkt->stratum);
+	record_raw_stats(&peer->srcadr, &peer->dstadr->sin, &p_org,
+	    &p_rec, &p_xmt, &peer->rec);
+	peer->leap = pleap;
+	peer->pmode = pmode;
+	peer->stratum = pstratum;
+	peer->ppoll = pkt->ppoll;
 	peer->precision = pkt->precision;
 	peer->rootdelay = p_del;
 	peer->rootdispersion = p_disp;
 	peer->refid = pkt->refid;
 	peer->reftime = p_reftime;
-	if (peer->reach == 0) {
+	if (!(peer->reach)) {
 		report_event(EVNT_REACH, peer);
 		peer->timereachable = current_time;
 	}
 	peer->reach |= 1;
+	peer->unreach = 0;
 	poll_update(peer, peer->hpoll);
 
 	/*
@@ -829,34 +995,25 @@ process_packet(
 	t23 = p_rec;			/* compute t2 - t3 */
 	L_SUB(&t23, &p_org);
 	ci = t10;
-	p_disp = CLOCK_PHI * (peer->rec.l_ui - p_org.l_ui);
+	p_disp = clock_phi * (peer->rec.l_ui - p_org.l_ui);
 
 	/*
 	 * If running in a broadcast association, the clock offset is
 	 * (t1 - t0) corrected by the one-way delay, but we can't
-	 * measure that directly; therefore, we start up in
-	 * client/server mode, calculate the clock offset, using the
-	 * engineered refinement algorithms, while also receiving
-	 * broadcasts. When a broadcast is received in client/server
-	 * mode, we calculate a correction factor to use after switching
-	 * back to broadcast mode. We know NTP_SKEWFACTOR == 16, which
-	 * accounts for the simplified ei calculation.
-	 *
-	 * If FLAG_MCAST2 is set, we are a broadcast/multicast client.
-	 * If FLAG_MCAST1 is set, we haven't calculated the propagation
-	 * delay. If hmode is MODE_CLIENT, we haven't set the local
-	 * clock in client/server mode. Initially, we come up
-	 * MODE_CLIENT. When the clock is first updated and FLAG_MCAST2
-	 * is set, we switch from MODE_CLIENT to MODE_BCLIENT.
+	 * measure that directly. Therefore, we start up in MODE_CLIENT
+	 * mode, set FLAG_MCAST and exchange eight messages to determine
+	 * the clock offset. When the last message is sent, we switch to
+	 * MODE_BCLIENT mode. The next broadcast message after that
+	 * computes the broadcast offset and clears FLAG_MCAST.
 	 */
 	if (pmode == MODE_BROADCAST) {
-		if (peer->flags & FLAG_MCAST1) {
-			if (peer->hmode == MODE_BCLIENT)
-				peer->flags &= ~FLAG_MCAST1;
+		if (peer->flags & FLAG_MCAST) {
 			LFPTOD(&ci, p_offset);
 			peer->estbdelay = peer->offset - p_offset;
-			return (1);
+			if (peer->hmode == MODE_CLIENT)
+				return;
 
+			peer->flags &= ~FLAG_MCAST;
 		}
 		DTOLFP(peer->estbdelay, &t10);
 		L_ADD(&ci, &t10);
@@ -867,32 +1024,29 @@ process_packet(
 		L_SUB(&t23, &t10);
 		LFPTOD(&t23, p_del);
 	}
+	p_del = max(p_del, LOGTOD(sys_precision));
 	LFPTOD(&ci, p_offset);
-	if (fabs(p_del) >= MAXDISPERSE || p_disp >= MAXDISPERSE) /* test 4 */
-		peer->flash |= TEST4;	/* delay/dispersion too big */
+	if ((peer->rootdelay + p_del) / 2. + peer->rootdispersion +
+	    p_disp >= MAXDISPERSE)		/* 9 */
+		peer->flash |= TEST9;		/* bad peer distance */
 
 	/*
-	 * If the packet data are invalid (tests 1 through 4), exit.
+	 * If any flasher bits remain set at this point, abandon ship.
+	 * Otherwise, forward to the clock filter.
 	 */
 	if (peer->flash) {
 #ifdef DEBUG
 		if (debug)
-			printf("invalid packet data 0x%02x mode %d\n",
-			    peer->flash, pmode);
+			printf("packet: bad packet data %03x\n",
+			    peer->flash);
 #endif
-		return(1);
+		return;
 	}
-
-
-	/*
-	 * This one is valid. Mark it so, give it to clock_filter().
-	 */
-	clock_filter(peer, p_offset, p_del, fabs(p_disp));
+	clock_filter(peer, p_offset, p_del, p_disp);
 	clock_select();
 	record_peer_stats(&peer->srcadr, ctlpeerstatus(peer),
 	    peer->offset, peer->delay, peer->disp,
-	    SQRT(peer->variance));
-	return(1);
+	    SQRT(peer->jitter));
 }
 
 
@@ -904,15 +1058,13 @@ clock_update(void)
 {
 	u_char oleap;
 	u_char ostratum;
-	int i;
-	struct peer *peer;
 
 	/*
 	 * Reset/adjust the system clock. Do this only if there is a
 	 * system peer and we haven't seen that peer lately. Watch for
 	 * timewarps here.
 	 */
-	if (sys_peer == 0)
+	if (sys_peer == NULL)
 		return;
 	if (sys_peer->pollsw == FALSE || sys_peer->burst > 0)
 		return;
@@ -924,60 +1076,58 @@ clock_update(void)
 #endif
 	oleap = sys_leap;
 	ostratum = sys_stratum;
-	switch (local_clock(sys_peer, sys_offset, sys_epsil)) {
+	switch (local_clock(sys_peer, sys_offset, sys_syserr)) {
 
-		case -1:
-		/*
-		 * Clock is too screwed up. Just exit for now.
-		 */
+	/*
+	 * Clock is too screwed up. Just exit for now.
+	 */
+	case -1:
 		report_event(EVNT_SYSFAULT, (struct peer *)0);
 		exit(1);
 		/*NOTREACHED*/
 
-		case 1:
-		/*
-		 * Clock was stepped. Clear filter registers
-		 * of all peers.
-		 */
-		for (i = 0; i < HASH_SIZE; i++) {
-			for (peer = peer_hash[i]; peer != 0;
-				peer =peer->next)
-				peer_clear(peer);
-		}
-		NLOG(NLOG_SYNCSTATUS)
-			msyslog(LOG_INFO, "synchronisation lost");
-		sys_peer = 0;
+	/*
+	 * Clock was stepped. Flush all time values of all peers.
+	 */
+	case 1:
+		clear_all();
+		sys_peer = NULL;
 		sys_stratum = STRATUM_UNSPEC;
+		sys_poll = NTP_MINPOLL;
+		NLOG(NLOG_SYNCSTATUS)
+		    msyslog(LOG_INFO, "synchronisation lost");
 		report_event(EVNT_CLOCKRESET, (struct peer *)0);
 		break;
 
-		default:
-		/*
-		 * Update the system stratum, leap bits, root delay,
-		 * root dispersion, reference ID and reference time. We
-		 * also update select dispersion and max frequency
-		 * error.
-		 */
+	/*
+	 * Update the system stratum, leap bits, root delay, root
+	 * dispersion, reference ID and reference time. We also update
+	 * select dispersion and max frequency error. If the leap
+	 * changes, we gotta reroll the keys.
+	 */
+	default:
 		sys_stratum = sys_peer->stratum + 1;
 		if (sys_stratum == 1)
 			sys_refid = sys_peer->refid;
 		else
 			sys_refid = sys_peer->srcadr.sin_addr.s_addr;
 		sys_reftime = sys_peer->rec;
-		sys_rootdelay = sys_peer->rootdelay +
-		    fabs(sys_peer->delay);
+		sys_rootdelay = sys_peer->rootdelay + sys_peer->delay;
 		sys_leap = leap_consensus;
 	}
-	if (oleap != sys_leap)
+	if (oleap == LEAP_NOTINSYNC) {
 		report_event(EVNT_SYNCCHG, (struct peer *)0);
+#ifdef AUTOKEY
+		expire_all();
+#endif /* AUTOKEY */
+	}
 	if (ostratum != sys_stratum)
 		report_event(EVNT_PEERSTCHG, (struct peer *)0);
 }
 
 
 /*
- * poll_update - update peer poll interval. See Section 3.4.9 of the
- *	   spec.
+ * poll_update - update peer poll interval
  */
 void
 poll_update(
@@ -985,46 +1135,83 @@ poll_update(
 	int hpoll
 	)
 {
-	long update;
+#ifdef AUTOKEY
+	int oldpoll;
+#endif /* AUTOKEY */
 
 	/*
-	 * The wiggle-the-poll-interval dance. Broadcasters dance only
-	 * the minpoll beat. Reference clock partners sit this one out.
-	 * Dancers surviving the clustering algorithm beat to the system
-	 * clock. Broadcast clients are usually lead by their broadcast
-	 * partner, but faster in the initial mating dance.
+	 * A little foxtrot to determine what controls the poll
+	 * interval. If the peer is reachable, but the last four polls
+	 * have not been answered, use the minimum. If declared
+	 * truechimer, use the system poll interval. This allows each
+	 * association to ramp up the poll interval for useless sources
+	 * and to clamp it to the minimum when first starting up.
 	 */
-	if (peer->hmode == MODE_BROADCAST) {
+#ifdef AUTOKEY
+	oldpoll = peer->kpoll;
+#endif /* AUTOKEY */
+	if (hpoll > peer->maxpoll)
+		peer->hpoll = peer->maxpoll;
+	else if (hpoll < peer->minpoll)
 		peer->hpoll = peer->minpoll;
-	} else if (peer->flags & FLAG_SYSPEER) {
-		peer->hpoll = sys_poll;
-	} else {
-		if (hpoll > peer->maxpoll)
-			peer->hpoll = peer->maxpoll;
-		else if (hpoll < peer->minpoll)
-			peer->hpoll = peer->minpoll;
-		else
-			peer->hpoll = hpoll;
-	}
+	else
+		peer->hpoll = hpoll;
+
+	/*
+	 * Bit of adventure here. If during a burst and not timeout,
+	 * just slink away. If timeout, figure what the next timeout
+	 * should be. If IBURST or a reference clock, use one second. If
+	 * not and the dude was reachable during the previous poll
+	 * interval, randomize over 1-4 seconds; otherwise, randomize
+	 * over 15-18 seconds. This is to give time for a modem to
+	 * complete the call, for example. If not during a burst,
+	 * randomize over the poll interval -1 to +2 seconds.
+	 *
+	 * In case of manycast server, make the poll interval, which is
+	 * axtually the manycast beacon interval, eight times the system
+	 * poll interval. Normally when the host poll interval settles
+	 * up to 17.1 s, the beacon interval settles up to 2.3 hours.
+	 */
 	if (peer->burst > 0) {
 		if (peer->nextdate != current_time)
 			return;
-		if (peer->flags & FLAG_REFCLOCK)
+#ifdef REFCLOCK
+		else if (peer->flags & FLAG_REFCLOCK)
 			peer->nextdate++;
+#endif
 		else if (peer->reach & 0x1)
 			peer->nextdate += RANDPOLL(BURST_INTERVAL2);
 		else
 			peer->nextdate += RANDPOLL(BURST_INTERVAL1);
+	} else if (peer->cast_flags & MDF_ACAST) {
+		if (sys_survivors < NTP_MINCLOCK)
+			peer->kpoll = peer->hpoll;
+		else
+			peer->kpoll = peer->hpoll + 3;
+		peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll);
 	} else {
-		update = max(min(peer->ppoll, peer->hpoll),
+		peer->kpoll = max(min(peer->ppoll, peer->hpoll),
 		    peer->minpoll);
-		peer->nextdate = peer->outdate + RANDPOLL(update);
+		peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll);
 	}
+	if (peer->nextdate < current_time)
+		peer->nextdate = current_time;
+#ifdef AUTOKEY
+	/*
+	 * Bit of crass arrogance at this point. If the poll interval
+	 * has changed and we have a keylist, the lifetimes in the
+	 * keylist are probably bogus. In this case purge the keylist
+	 * and regenerate it later.
+	 */
+	if (peer->kpoll != oldpoll)
+		key_expire(peer);
+#endif /* AUTOKEY */
 #ifdef DEBUG
 	if (debug > 1)
-		printf("poll_update: at %lu %s poll %d burst %d last %lu next %lu\n",
-		    current_time, ntoa(&peer->srcadr), hpoll,
-		    peer->burst, peer->outdate, peer->nextdate);
+		printf("poll_update: at %lu %s flags %04x poll %d burst %d last %lu next %lu\n",
+		    current_time, ntoa(&peer->srcadr), peer->flags,
+		    peer->kpoll, peer->burst, peer->outdate,
+		    peer->nextdate);
 #endif
 }
 
@@ -1038,28 +1225,72 @@ peer_clear(
 	)
 {
 	register int i;
+	u_long u_rand;
 
+	/*
+	 * If cryptographic credentials have been acquired, toss them to
+	 * Valhalla. Note that autokeys are ephemeral, in that they are
+	 * tossed immediately upon use. Therefore, the keylist can be
+	 * purged anytime without needing to preserve random keys. Note
+	 * that, if the peer is purged, the cryptographic variables are
+	 * purged, too. This makes it much harder to sneak in some
+	 * unauthenticated data in the clock filter.
+	 */
+#ifdef DEBUG
+	if (debug)
+		printf("peer_clear: at %ld assoc ID %d\n", current_time,
+		    peer->associd);
+#endif
+#ifdef AUTOKEY
+	key_expire(peer);
+#ifdef PUBKEY
+	if (peer->keystr != NULL)
+		free(peer->keystr);
+	if (peer->pubkey.ptr != NULL)
+		free(peer->pubkey.ptr);
+	if (peer->certif.ptr != NULL)
+		free(peer->certif.ptr);
+#endif /* PUBKEY */
+#endif /* AUTOKEY */
 	memset(CLEAR_TO_ZERO(peer), 0, LEN_CLEAR_TO_ZERO);
+
+	/*
+	 * If he dies as a broadcast client, he comes back to life as
+	 * a broadcast client in client mode in order to recover the
+	 * initial autokey values. Note that there is no need to call
+	 * clock_select(), since the perp has already been voted off
+	 * the island at this point.
+	 */
+	if (peer->cast_flags & MDF_BCLNT) {
+		peer->flags |= FLAG_MCAST;
+		peer->hmode = MODE_CLIENT;
+	}
+	peer->flags &= ~(FLAG_AUTOKEY | FLAG_ASSOC);
 	peer->estbdelay = sys_bdelay;
-	peer->hpoll = peer->minpoll;
+	peer->hpoll = peer->kpoll = peer->minpoll;
+	peer->ppoll = peer->maxpoll;
 	peer->pollsw = FALSE;
-	peer->variance = MAXDISPERSE;
+	peer->jitter = MAXDISPERSE;
 	peer->epoch = current_time;
+#ifdef REFCLOCK
+	if (!(peer->flags & FLAG_REFCLOCK)) {
+		peer->leap = LEAP_NOTINSYNC;
+		peer->stratum = STRATUM_UNSPEC;
+	}
+#endif
 	for (i = 0; i < NTP_SHIFT; i++) {
 		peer->filter_order[i] = i;
 		peer->filter_disp[i] = MAXDISPERSE;
 		peer->filter_epoch[i] = current_time;
 	}
-	poll_update(peer, peer->minpoll);
 
 	/*
-	 * Since we have a chance to correct possible funniness in
-	 * our selection of interfaces on a multihomed host, do so
-	 * by setting us to no particular interface.
-	 * WARNING: do so only in non-broadcast mode!
+	 * Randomize the first poll over 1-16s to avoid bunching.
 	 */
-	if (peer->hmode != MODE_BROADCAST)
-		peer->dstadr = any_interface;
+	peer->update = peer->outdate = current_time;
+	u_rand = RANDOM;
+	peer->nextdate = current_time + (u_rand & ((1 <<
+	    BURST_INTERVAL1) - 1)) + 1;
 }
 
 
@@ -1069,130 +1300,172 @@ peer_clear(
  */
 void
 clock_filter(
-	register struct peer *peer,
-	double sample_offset,
-	double sample_delay,
-	double sample_disp
+	register struct peer *peer,	/* peer structure pointer */
+	double sample_offset,		/* clock offset */
+	double sample_delay,		/* roundtrip delay */
+	double sample_disp		/* dispersion */
 	)
 {
-	register int i, j, k, n = 0;
-	register u_char *ord;
-	double distance[NTP_SHIFT];
-	double x, y, z, off;
+	double dst[NTP_SHIFT];		/* distance vector */
+	int ord[NTP_SHIFT];		/* index vector */
+	register int i, j, k, m;
+	double dsp, jit, dtemp, etemp;
 
 	/*
-	 * Update error bounds and calculate distances. Also initialize
-	 * sort index vector.
+	 * Shift the new sample into the register and discard the oldest
+	 * one. The new offset and delay come directly from the
+	 * timestamp calculations. The dispersion grows from the last
+	 * outbound packet or reference clock update to the present time
+	 * and increased by the sum of the peer precision and the system
+	 * precision. The delay can sometimes swing negative due to
+	 * frequency skew, so it is clamped non-negative.
 	 */
-	x = CLOCK_PHI * (current_time - peer->update);
-	peer->update = current_time;
-	ord = peer->filter_order;
+	dsp = min(LOGTOD(peer->precision) + LOGTOD(sys_precision) +
+	    sample_disp, MAXDISPERSE);
 	j = peer->filter_nextpt;
-	for (i = 0; i < NTP_SHIFT; i++) {
-		peer->filter_disp[j] += x;
-		if (peer->filter_disp[j] > MAXDISPERSE)
-			peer->filter_disp[j] = MAXDISPERSE;
-		distance[i] = fabs(peer->filter_delay[j]) / 2 +
-		    peer->filter_disp[j];
-		ord[i] = j;
-		if (--j < 0)
-			j += NTP_SHIFT;
-	}
+	peer->filter_offset[j] = sample_offset;
+	peer->filter_delay[j] = max(0, sample_delay);
+	peer->filter_disp[j] = dsp;
+	peer->filter_epoch[j] = current_time;
+	j++; j %=NTP_SHIFT;
+	peer->filter_nextpt = j;
 
 	/*
-	 * Insert the new sample at the beginning of the register.
+	 * Update dispersions since the last update and at the same
+	 * time initialize the distance and index lists. The distance
+	 * list uses a compound metric. If the sample is valid and
+	 * younger than the minimum Allan intercept, use delay;
+	 * otherwise, use biased dispersion.
 	 */
-	peer->filter_offset[peer->filter_nextpt] = sample_offset;
-	peer->filter_delay[peer->filter_nextpt] = sample_delay;
-	x = LOGTOD(peer->precision) + LOGTOD(sys_precision) +
-	    sample_disp;
-	peer->filter_disp[peer->filter_nextpt] = min(x, MAXDISPERSE);
-	peer->filter_epoch[peer->filter_nextpt] = current_time;
-	distance[0] = min(x + fabs(sample_delay) / 2, MAXDISTANCE);
-	peer->filter_nextpt++;
-	if (peer->filter_nextpt >= NTP_SHIFT)
-		peer->filter_nextpt = 0;
+	dtemp = clock_phi * (current_time - peer->update);
+	peer->update = current_time;
+	for (i = NTP_SHIFT - 1; i >= 0; i--) {
+		if (i != 0) {
+			peer->filter_disp[j] += dtemp;
+			if (peer->filter_disp[j] > MAXDISPERSE)
+				peer->filter_disp[j] = MAXDISPERSE;
+		}
+		if (peer->filter_disp[j] >= MAXDISPERSE)
+			dst[i] = MAXDISPERSE;
+		else if (peer->update - peer->filter_epoch[j] >
+		    allan_xpt)
+			dst[i] = MAXDISTANCE + peer->filter_disp[j];
+		else
+ 			dst[i] = peer->filter_delay[j];
+		ord[i] = j;
+		j++; j %= NTP_SHIFT;
+	}
 
-	/*
-	 * Sort the samples in the register by distance. The winning
-	 * sample will be in ord[0]. Sort the samples only if they
-	 * are younger than the Allen intercept.
+        /*
+	 * Sort the samples in both lists by distance.
 	 */
-	y = min(allan_xpt, NTP_SHIFT * ULOGTOD(sys_poll));
-	for (n = 0; n < NTP_SHIFT && current_time -
-	    peer->filter_epoch[ord[n]] <= y; n++) {
-		for (j = 0; j < n; j++) {
-			if (distance[j] > distance[n]) {
-				x = distance[j];
+	for (i = 1; i < NTP_SHIFT; i++) {
+		for (j = 0; j < i; j++) {
+			if (dst[j] > dst[i]) {
 				k = ord[j];
-				distance[j] = distance[n];
-				ord[j] = ord[n];
-				distance[n] = x;
-				ord[n] = k;
+				ord[j] = ord[i];
+				ord[i] = k;
+				etemp = dst[j];
+				dst[j] = dst[i];
+				dst[i] = etemp;
 			}
 		}
-	} 
+	}
+
+	/*
+	 * Copy the index list to the association structure so ntpq
+	 * can see it later. Prune the distance list to samples less
+	 * than MAXDISTANCE, but keep at least two valid samples for
+	 * jitter calculation.
+	 */
+	m = 0;
+	for (i = 0; i < NTP_SHIFT; i++) {
+		peer->filter_order[i] = ord[i];
+		if (dst[i] >= MAXDISPERSE || (m >= 2 && dst[i] >=
+		    MAXDISTANCE))
+			continue;
+		m++;
+	}
 	
 	/*
-	 * Compute the error bound and standard error.
+	 * Compute the dispersion and jitter squares. The dispersion
+	 * is weighted exponentially by NTP_FWEIGHT (0.5) so it is
+	 * normalized close to 1.0. The jitter is the mean of the square
+	 * differences relative to the lowest delay sample. If no
+	 * acceptable samples remain in the shift register, quietly
+	 * tiptoe home leaving only the
+	 * dispersion.
 	 */
-	x = y = z = off = 0.;
+	jit = 0;
+	peer->disp = 0;
+	k = ord[0];
 	for (i = NTP_SHIFT - 1; i >= 0; i--) {
-		x = NTP_FWEIGHT * (x + peer->filter_disp[ord[i]]);
-		if (i < n) {
-			z += 1. / distance[i];
-			off += peer->filter_offset[ord[i]] /
-			    distance[i];
-			y += DIFF(peer->filter_offset[ord[i]],
-			    peer->filter_offset[ord[0]]);
-		}
+
+		j = ord[i];
+		peer->disp = NTP_FWEIGHT * (peer->disp +
+		    peer->filter_disp[j]);
+		if (i < m)
+			jit += DIFF(peer->filter_offset[j],
+			    peer->filter_offset[k]);
 	}
-	peer->delay = peer->filter_delay[ord[0]];
-	peer->variance = min(y / n, MAXDISPERSE);
-	peer->disp = min(x, MAXDISPERSE);
-	peer->epoch = current_time;
-	x = peer->offset;
-	if (peer->flags & FLAG_BURST)
-		peer->offset = off / z;
-	else
-		peer->offset = peer->filter_offset[ord[0]];
+
+	/*
+	 * If no acceptable samples remain in the shift register,
+	 * quietly tiptoe home leaving only the dispersion. Otherwise,
+	 * save the offset, delay and jitter average. Note the jitter
+	 * must not be less than the system precision.
+	 */
+	if (m == 0)
+		return;
+	etemp = peer->offset;
+	peer->offset = peer->filter_offset[k];
+	peer->delay = peer->filter_delay[k];
+	if (m > 1)
+		jit /= m - 1;
+	peer->jitter = max(jit, SQUARE(LOGTOD(sys_precision)));
 
 	/*
 	 * A new sample is useful only if it is younger than the last
 	 * one used.
 	 */
-	if (peer->filter_epoch[ord[0]] > peer->epoch) {
+	if (peer->filter_epoch[k] <= peer->epoch) {
 #ifdef DEBUG
 		if (debug)
 			printf("clock_filter: discard %lu\n",
-			    peer->filter_epoch[ord[0]] - peer->epoch);
+			    peer->epoch - peer->filter_epoch[k]);
 #endif
 		return;
 	}
 
 	/*
-	 * If the offset exceeds the dispersion by CLOCK_SGATE and the
-	 * interval since the last update is less than twice the system
-	 * poll interval, consider the update a popcorn spike and ignore
-	 * it.
+	 * If the difference between the last offset and the current one
+	 * exceeds the jitter by CLOCK_SGATE (4) and the interval since
+	 * the last update is less than twice the system poll interval,
+	 * consider the update a popcorn spike and ignore it.
 	 */
-	if (fabs(x - peer->offset) > CLOCK_SGATE &&
-	    peer->filter_epoch[ord[0]] - peer->epoch < (1 <<
-	    (sys_poll + 1))) {
+	if (m > 1 && fabs(peer->offset - etemp) > SQRT(peer->jitter) *
+	    CLOCK_SGATE && peer->filter_epoch[k] - peer->epoch <
+	    (1 << (sys_poll + 1))) {
 #ifdef DEBUG
 		if (debug)
-			printf("clock_filter: popcorn spike %.6f\n", x);
+			printf("clock_filter: n %d popcorn spike %.6f jitter %.6f\n",
+			    m, peer->offset, SQRT(peer->jitter));
 #endif
 		return;
 	}
-	peer->epoch = peer->filter_epoch[ord[0]];
+
+	/*
+	 * The mitigated sample statistics are saved for later
+	 * processing, but can be processed only once.
+	 */
+	peer->epoch = peer->filter_epoch[k];
 	peer->pollsw = TRUE;
 #ifdef DEBUG
 	if (debug)
 		printf(
-		    "clock_filter: offset %.6f delay %.6f disp %.6f std %.6f, age %lu\n",
-		    peer->offset, peer->delay, peer->disp,
-		    SQRT(peer->variance), current_time - peer->epoch);
+		    "clock_filter: n %d off %.6f del %.6f dsp %.6f jit %.6f, age %lu\n",
+		    m, peer->offset, peer->delay, peer->disp,
+		    SQRT(peer->jitter), peer->update - peer->epoch);
 #endif
 }
 
@@ -1204,35 +1477,34 @@ void
 clock_select(void)
 {
 	register struct peer *peer;
-	int i;
-	int nlist, nl3;
+	int i, j, k, n;
+	int nreach, nlist, nl3;
 	double d, e, f;
-	int j;
-	int n;
-	int allow, found, k;
+	int allow, found, sw;
 	double high, low;
 	double synch[NTP_MAXCLOCK], error[NTP_MAXCLOCK];
 	struct peer *osys_peer;
-	struct peer *typeacts = 0;
-	struct peer *typelocal = 0;
-	struct peer *typepps = 0;
-	struct peer *typeprefer = 0;
-	struct peer *typesystem = 0;
+	struct peer *typeacts = NULL;
+	struct peer *typelocal = NULL;
+	struct peer *typepps = NULL;
+	struct peer *typesystem = NULL;
 
 	static int list_alloc = 0;
 	static struct endpoint *endpoint = NULL;
-	static int *index = NULL;
+	static int *indx = NULL;
 	static struct peer **peer_list = NULL;
 	static u_int endpoint_size = 0;
-	static u_int index_size = 0;
+	static u_int indx_size = 0;
 	static u_int peer_list_size = 0;
 
 	/*
-	 * Initialize. If a prefer peer does not survive this thing,
-	 * the pps_update switch will remain zero.
+	 * Initialize and create endpoint, index and peer lists big
+	 * enough to handle all associations.
 	 */
-	pps_update = 0;
-	nlist = 0;
+	osys_peer = sys_peer;
+	sys_peer = NULL;
+	sys_prefer = NULL;
+	nreach = nlist = 0;
 	low = 1e9;
 	high = -1e9;
 	for (n = 0; n < HASH_SIZE; n++)
@@ -1240,49 +1512,58 @@ clock_select(void)
 	if (nlist > list_alloc) {
 		if (list_alloc > 0) {
 			free(endpoint);
-			free(index);
+			free(indx);
 			free(peer_list);
 		}
 		while (list_alloc < nlist) {
 			list_alloc += 5;
-			endpoint_size += 5 * 3 * sizeof *endpoint;
-			index_size += 5 * 3 * sizeof *index;
-			peer_list_size += 5 * sizeof *peer_list;
+			endpoint_size += 5 * 3 * sizeof(*endpoint);
+			indx_size += 5 * 3 * sizeof(*indx);
+			peer_list_size += 5 * sizeof(*peer_list);
 		}
 		endpoint = (struct endpoint *)emalloc(endpoint_size);
-		index = (int *)emalloc(index_size);
+		indx = (int *)emalloc(indx_size);
 		peer_list = (struct peer **)emalloc(peer_list_size);
 	}
 
 	/*
-	 * This first chunk of code is supposed to go through all
-	 * peers we know about to find the peers which are most likely
-	 * to succeed. We run through the list doing the sanity checks
-	 * and trying to insert anyone who looks okay.
+	 * Initially, we populate the island with all the rifraff peers
+	 * that happen to be lying around. Those with seriously
+	 * defective clocks are immediately booted off the island. Then,
+	 * the falsetickers are culled and put to sea. The truechimers
+	 * remaining are subject to repeated rounds where the most
+	 * unpopular at each round is kicked off. When the population
+	 * has dwindled to NTP_MINCLOCK (3), the survivors split a
+	 * million bucks and collectively crank the chimes.
 	 */
 	nlist = nl3 = 0;	/* none yet */
 	for (n = 0; n < HASH_SIZE; n++) {
-		for (peer = peer_hash[n]; peer != 0; peer = peer->next) {
+		for (peer = peer_hash[n]; peer != NULL; peer =
+		    peer->next) {
 			peer->flags &= ~FLAG_SYSPEER;
 			peer->status = CTL_PST_SEL_REJECT;
-			if (peer->flags & FLAG_NOSELECT)
-				continue;	/* noselect (survey) */
-			if (peer->reach == 0)
-				continue;	/* unreachable */
-			if (peer->stratum > 1 && peer->refid ==
-			    peer->dstadr->sin.sin_addr.s_addr)
-				continue;	/* sync loop */
-			if (root_distance(peer) >= MAXDISTANCE + 2 *
-			    CLOCK_PHI * ULOGTOD(sys_poll)) {
-				peer->seldisptoolarge++;
-				continue;	/* noisy or broken */
-			}
 
 			/*
-			 * Don't allow the local-clock or acts drivers
+			 * A peer leaves the island immediately if
+			 * unreachable, synchronized to us or suffers
+			 * excessive root distance. Careful with the
+			 * root distance, since the poll interval can
+			 * increase to a day and a half.
+			 */ 
+			if (!peer->reach || (peer->stratum > 1 &&
+			    peer->refid ==
+			    peer->dstadr->sin.sin_addr.s_addr) ||
+			    peer->stratum >= STRATUM_UNSPEC ||
+			    (root_distance(peer) >= MAXDISTANCE + 2 *
+			    clock_phi * ULOGTOD(sys_poll)))
+				continue;
+
+			/*
+			 * Don't allow the local clock or modem drivers
 			 * in the kitchen at this point, unless the
 			 * prefer peer. Do that later, but only if
-			 * nobody else is around.
+			 * nobody else is around. These guys are all
+			 * configured, so we never throw them away.
 			 */
 			if (peer->refclktype == REFCLK_LOCALCLOCK
 #if defined(VMS) && defined(VMS_LOCALUNIT)
@@ -1301,9 +1582,11 @@ clock_select(void)
 			}
 
 			/*
-			 * If we get this far, we assume the peer is
-			 * acceptable.
+			 * If we get this far, the peer can stay on the
+			 * island, but does not yet have the immunity
+			 * idol.
 			 */
+			nreach++;
 			peer->status = CTL_PST_SEL_SANE;
 			peer_list[nlist++] = peer;
 
@@ -1315,40 +1598,41 @@ clock_select(void)
 			f = root_distance(peer);
 			e = e + f;
 			for (i = nl3 - 1; i >= 0; i--) {
-				if (e >= endpoint[index[i]].val)
+				if (e >= endpoint[indx[i]].val)
 					break;
-				index[i + 3] = index[i];
+				indx[i + 3] = indx[i];
 			}
-			index[i + 3] = nl3;
+			indx[i + 3] = nl3;
 			endpoint[nl3].type = 1;
 			endpoint[nl3++].val = e;
 
 			e = e - f;		/* Center point */
 			for ( ; i >= 0; i--) {
-				if (e >= endpoint[index[i]].val)
+				if (e >= endpoint[indx[i]].val)
 					break;
-				index[i + 2] = index[i];
+				indx[i + 2] = indx[i];
 			}
-			index[i + 2] = nl3;
+			indx[i + 2] = nl3;
 			endpoint[nl3].type = 0;
 			endpoint[nl3++].val = e;
 
 			e = e - f;		/* Lower end */
 			for ( ; i >= 0; i--) {
-				if (e >= endpoint[index[i]].val)
+				if (e >= endpoint[indx[i]].val)
 					break;
-				index[i + 1] = index[i];
+				indx[i + 1] = indx[i];
 			}
-			index[i + 1] = nl3;
+			indx[i + 1] = nl3;
 			endpoint[nl3].type = -1;
 			endpoint[nl3++].val = e;
 		}
 	}
 #ifdef DEBUG
-	if (debug > 1)
+	if (debug > 2)
 		for (i = 0; i < nl3; i++)
-		printf("select: endpoint %2d %.6f\n",
-		   endpoint[index[i]].type, endpoint[index[i]].val);
+			printf("select: endpoint %2d %.6f\n",
+			   endpoint[indx[i]].type,
+			   endpoint[indx[i]].val);
 #endif
 	i = 0;
 	j = nl3 - 1;
@@ -1357,30 +1641,30 @@ clock_select(void)
 	while (allow > 0) {
 		allow--;
 		for (n = 0; i <= j; i++) {
-			n += endpoint[index[i]].type;
+			n += endpoint[indx[i]].type;
 			if (n < 0)
 				break;
-			if (endpoint[index[i]].type == 0)
+			if (endpoint[indx[i]].type == 0)
 				found++;
 		}
 		for (n = 0; i <= j; j--) {
-			n += endpoint[index[j]].type;
+			n += endpoint[indx[j]].type;
 			if (n > 0)
 				break;
-			if (endpoint[index[j]].type == 0)
+			if (endpoint[indx[j]].type == 0)
 				found++;
 		}
 		if (found > allow)
 			break;
-		low = endpoint[index[i++]].val;
-		high = endpoint[index[j--]].val;
+		low = endpoint[indx[i++]].val;
+		high = endpoint[indx[j--]].val;
 	}
 
 	/*
-	 * If no survivors remain at this point, check if the acts or
-	 * local clock drivers have been found. If so, nominate one of
-	 * them as the only survivor. Otherwise, give up and declare us
-	 * unsynchronized.
+	 * If no survivors remain at this point, check if the local
+	 * clock or modem drivers have been found. If so, nominate one
+	 * of them as the only survivor. Otherwise, give up and declare
+	 * us unsynchronized.
 	 */
 	if ((allow << 1) >= nlist) {
 		if (typeacts != 0) {
@@ -1392,35 +1676,45 @@ clock_select(void)
 			peer_list[0] = typelocal;
 			nlist = 1;
 		} else {
-			if (sys_peer != 0) {
-				report_event(EVNT_PEERSTCHG,
-				    (struct peer *)0);
+			if (osys_peer != NULL) {
+				sys_poll = NTP_MINPOLL;
 				NLOG(NLOG_SYNCSTATUS)
-				msyslog(LOG_INFO,
+				    msyslog(LOG_INFO,
 				    "synchronisation lost");
+				report_event(EVNT_PEERSTCHG,
+				    (struct peer *)0);
 			}
-			sys_peer = 0;
+			sys_survivors = 0;
+#ifdef AUTOKEY
+			resetmanycast();
+#endif /* AUTOKEY */
 			return;
 		}
 	}
 #ifdef DEBUG
-	if (debug > 1)
+	if (debug > 2)
 		printf("select: low %.6f high %.6f\n", low, high);
 #endif
 
 	/*
-	 * Clustering algorithm. Process intersection list to discard
-	 * outlyers. Construct candidate list in cluster order
-	 * determined by the sum of peer synchronization distance plus
-	 * scaled stratum. We must find at least one peer.
+	 * Clustering algorithm. Construct candidate list in order first
+	 * by stratum then by root distance. If we have more than
+	 * MAXCLOCK peers, keep only the best MAXCLOCK of them. Scan the
+	 * list to find falsetickers, who leave the island immediately.
+	 * If a falseticker is not configured, his association raft is
+	 * drowned as well. We must leave at least one peer to collect
+	 * the million bucks.
 	 */
 	j = 0;
 	for (i = 0; i < nlist; i++) {
 		peer = peer_list[i];
-		if (nlist > 1 && (low >= peer->offset ||
-			peer->offset >= high))
+		if (nlist > 1 && (low >= peer->offset || peer->offset >=
+		    high)) {
+			if (!(peer->flags & FLAG_CONFIG))
+				unpeer(peer);
 			continue;
-		peer->status = CTL_PST_SEL_CORRECT;
+		}
+		peer->status = CTL_PST_SEL_DISTSYSPEER;
 		d = root_distance(peer) + peer->stratum * MAXDISPERSE;
 		if (j >= NTP_MAXCLOCK) {
 			if (d >= synch[j - 1])
@@ -1431,77 +1725,98 @@ clock_select(void)
 		for (k = j; k > 0; k--) {
 			if (d >= synch[k - 1])
 				break;
-			synch[k] = synch[k - 1];
 			peer_list[k] = peer_list[k - 1];
+			error[k] = error[k - 1];
+			synch[k] = synch[k - 1];
 		}
 		peer_list[k] = peer;
+		error[k] = peer->jitter;
 		synch[k] = d;
 		j++;
 	}
 	nlist = j;
+	for (i = 0; i < nlist; i++) {
+		peer_list[i]->status = CTL_PST_SEL_SELCAND;
 
 #ifdef DEBUG
-	if (debug > 1)
-		for (i = 0; i < nlist; i++)
+		if (debug > 2)
 			printf("select: %s distance %.6f\n",
 			    ntoa(&peer_list[i]->srcadr), synch[i]);
 #endif
+	}
 
 	/*
-	 * Now, prune outlyers by root dispersion. Continue as long as
-	 * there are more than NTP_MINCLOCK survivors and the minimum
-	 * select dispersion is greater than the maximum peer
-	 * dispersion. Stop if we are about to discard a prefer peer.
+	 * Now, vote outlyers off the island by select jitter weighted
+	 * by root dispersion. Continue voting as long as there are more
+	 * than NTP_MINCLOCK survivors and the minimum select jitter
+	 * squared is greater than the maximum peer jitter squared. Stop
+	 * if we are about to discard a prefer peer, who of course has
+	 * the immunity idol.
 	 */
-	for (i = 0; i < nlist; i++) {
-		peer = peer_list[i];
-		error[i] = peer->variance;
-		if (i < NTP_CANCLOCK)
-			peer->status = CTL_PST_SEL_SELCAND;
-		else
-			peer->status = CTL_PST_SEL_DISTSYSPEER;
-	}
 	while (1) {
-		sys_maxd = 0;
-		d = error[0];
-		for (k = i = nlist - 1; i >= 0; i--) {
-			double sdisp = 0;
-
-			for (j = nlist - 1; j > 0; j--) {
-				sdisp = NTP_SWEIGHT * (sdisp +
-					DIFF(peer_list[i]->offset,
-					peer_list[j]->offset));
+		d = 1e9;
+		e = -1e9;
+		k = 0;
+		for (i = 0; i < nlist; i++) {
+
+			if (error[i] < d)
+				d = error[i];
+			f = 0;
+			if (nlist > 1) {
+				for (j = 0; j < nlist; j++)
+					f += DIFF(peer_list[j]->offset,
+					    peer_list[i]->offset);
+				f /= nlist - 1;
 			}
-			if (sdisp > sys_maxd) {
-				sys_maxd = sdisp;
+			f = max(f, SQUARE(LOGTOD(sys_precision))); 
+			if (f * synch[i] > e) {
+				sys_selerr = f;
+				e = f * synch[i];
 				k = i;
 			}
-			if (error[i] < d)
-				d = error[i];
 		}
 
 #ifdef DEBUG
-		if (debug > 1)
+		if (debug > 2)
 			printf(
 			    "select: survivors %d select %.6f peer %.6f\n",
-			    nlist, SQRT(sys_maxd), SQRT(d));
+			    k, SQRT(sys_selerr), SQRT(d));
 #endif
-		if (nlist <= NTP_MINCLOCK || sys_maxd <= d ||
-			peer_list[k]->flags & FLAG_PREFER)
+		if (nlist <= NTP_MINCLOCK || sys_selerr <= d ||
+		    peer_list[k]->flags & FLAG_PREFER)
 			break;
+		if (!(peer_list[k]->flags & FLAG_CONFIG))
+			unpeer(peer_list[k]);
 		for (j = k + 1; j < nlist; j++) {
 			peer_list[j - 1] = peer_list[j];
 			error[j - 1] = error[j];
 		}
 		nlist--;
 	}
+
+#ifdef AUTOKEY
+	/*
+	 * In manycast client mode we may have spooked a sizeable number
+	 * of servers that we don't need. If there are at least
+	 * NTP_MINCLOCK of them, the manycast message will be turned
+	 * off. By the time we get here we nay be ready to prune some of
+	 * them back, but we want to make sure all the candicates have
+	 * had a chance. If they didn't pass the sanity and intersection
+	 * tests, they have already been voted off the island.
+	 */
+	if (sys_survivors >= NTP_MINCLOCK && nlist < NTP_MINCLOCK)
+		resetmanycast();
+#endif /* AUTOKEY */
+	sys_survivors = nlist;
+
 #ifdef DEBUG
-	if (debug > 1) {
+	if (debug > 2) {
 		for (i = 0; i < nlist; i++)
 			printf(
 			    "select: %s offset %.6f, distance %.6f poll %d\n",
-			    ntoa(&peer_list[i]->srcadr), peer_list[i]->offset,
-			    synch[i], peer_list[i]->pollsw);
+			    ntoa(&peer_list[i]->srcadr),
+			    peer_list[i]->offset, synch[i],
+			    peer_list[i]->pollsw);
 	}
 #endif
 
@@ -1520,27 +1835,30 @@ clock_select(void)
 	 * him. We note that the head of the list is at the lowest
 	 * stratum and that unsynchronized peers cannot survive this
 	 * far.
+	 *
+	 * Note that we go no further, unless the number of survivors is
+	 * a majority of the suckers that have been found reachable and
+	 * no prior source is available. This avoids the transient when
+	 * one of a flock of sources is out to lunch and just happens
+	 * to be the first survivor.
 	 */
+	if (osys_peer == NULL && 2 * nlist < min(nreach, NTP_MINCLOCK))
+		return;
 	leap_consensus = 0;
 	for (i = nlist - 1; i >= 0; i--) {
-		peer_list[i]->status = CTL_PST_SEL_SYNCCAND;
-		peer_list[i]->flags |= FLAG_SYSPEER;
-		poll_update(peer_list[i], peer_list[i]->hpoll);
-		if (peer_list[i]->stratum == peer_list[0]->stratum) {
-			leap_consensus |= peer_list[i]->leap;
-			if (peer_list[i]->refclktype == REFCLK_ATOM_PPS)
-				typepps = peer_list[i];
-			if (peer_list[i] == sys_peer)
-				typesystem = peer_list[i];
-			if (peer_list[i]->flags & FLAG_PREFER) {
-				typeprefer = peer_list[i];
-				if (fabs(typeprefer->offset) <
-				    clock_max)
-					pps_update = 1;
-			}
-		} else {
-			if (peer_list[i] == sys_peer)
-				sys_peer = 0;
+		peer = peer_list[i];
+		peer->status = CTL_PST_SEL_SYNCCAND;
+		peer->flags |= FLAG_SYSPEER;
+		poll_update(peer, peer->hpoll);
+		if (peer->stratum == peer_list[0]->stratum) {
+			leap_consensus |= peer->leap;
+			if (peer->refclktype == REFCLK_ATOM_PPS &&
+			    peer->stratum < STRATUM_UNSPEC)
+				typepps = peer;
+			if (peer == osys_peer)
+				typesystem = peer;
+			if (peer->flags & FLAG_PREFER)
+				sys_prefer = peer;
 		}
 	}
 
@@ -1556,38 +1874,45 @@ clock_select(void)
 	 * stated. Note that all of these must be at the lowest stratum,
 	 * i.e., the stratum of the head of the survivor list.
 	 */
-	osys_peer = sys_peer;
-	if (typeprefer && (typeprefer->refclktype == REFCLK_LOCALCLOCK
-	    || typeprefer->sstclktype == CTL_SST_TS_TELEPHONE ||
-		!typepps)) {
-		sys_peer = typeprefer;
+	if (sys_prefer)
+		sw = sys_prefer->refclktype == REFCLK_LOCALCLOCK ||
+		    sys_prefer->sstclktype == CTL_SST_TS_TELEPHONE ||
+		    !typepps;
+	else
+		sw = 0;
+	if (sw) {
+		sys_peer = sys_prefer;
 		sys_peer->status = CTL_PST_SEL_SYSPEER;
 		sys_offset = sys_peer->offset;
-		sys_epsil = sys_peer->variance;
+		sys_syserr = sys_peer->jitter;
 #ifdef DEBUG
 		if (debug > 1)
 			printf("select: prefer offset %.6f\n",
 			    sys_offset);
 #endif
-	} else if (typepps && pps_update) {
+	} else if (typepps) {
 		sys_peer = typepps;
 		sys_peer->status = CTL_PST_SEL_PPS;
 		sys_offset = sys_peer->offset;
-		sys_epsil = sys_peer->variance;
+		sys_syserr = sys_peer->jitter;
 		if (!pps_control)
-			NLOG(NLOG_SYSEVENT) /* conditional syslog */
-				msyslog(LOG_INFO, "pps sync enabled");
+			NLOG(NLOG_SYSEVENT)
+			    msyslog(LOG_INFO,
+			    "pps sync enabled");
 		pps_control = current_time;
 #ifdef DEBUG
 		if (debug > 1)
-			printf("select: pps offset %.6f\n", sys_offset);
+			printf("select: pps offset %.6f\n",
+			    sys_offset);
 #endif
 	} else {
-		if (!typesystem)
+		if (typesystem)
+			sys_peer = osys_peer;
+		else
 			sys_peer = peer_list[0];
 		sys_peer->status = CTL_PST_SEL_SYSPEER;
 		sys_offset = clock_combine(peer_list, nlist);
-		sys_epsil = sys_peer->variance + sys_maxd;
+		sys_syserr = sys_peer->jitter + sys_selerr;
 #ifdef DEBUG
 		if (debug > 1)
 			printf("select: combine offset %.6f\n",
@@ -1627,10 +1952,14 @@ root_distance(
 	struct peer *peer
 	)
 {
-	return ((fabs(peer->delay) + peer->rootdelay) / 2 +
-		peer->rootdispersion + peer->disp +
-		    SQRT(peer->variance) + CLOCK_PHI * (current_time -
-		    peer->update));
+	/*
+	 * Careful squeak here. The value returned must be greater than
+	 * zero blamed on the peer jitter, which must be at least the
+	 * square of sys_precision.
+	 */
+	return ((peer->rootdelay + peer->delay) / 2 +
+	    peer->rootdispersion + peer->disp + clock_phi *
+	    (current_time - peer->update) + SQRT(peer->jitter));
 }
 
 /*
@@ -1641,279 +1970,518 @@ peer_xmit(
 	struct peer *peer	/* peer structure pointer */
 	)
 {
-	struct pkt xpkt;
-	int find_rtt = (peer->cast_flags & MDF_MCAST) &&
-		peer->hmode != MODE_BROADCAST;
-	int sendlen;
+	struct pkt xpkt;	/* transmit packet */
+	int sendlen, authlen;
+	keyid_t xkeyid;		/* transmit key ID */
+	l_fp xmt_tx;
 
 	/*
-	 * Initialize protocol fields.
+	 * Initialize transmit packet header fields.
 	 */
-	xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap,
-		peer->version, peer->hmode);
+	xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, peer->version,
+	    peer->hmode);
 	xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
 	xpkt.ppoll = peer->hpoll;
 	xpkt.precision = sys_precision;
 	xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
-	xpkt.rootdispersion = HTONS_FP(DTOUFP(sys_rootdispersion +
-		LOGTOD(sys_precision)));
+	xpkt.rootdispersion = HTONS_FP(DTOUFP(sys_rootdispersion));
 	xpkt.refid = sys_refid;
 	HTONL_FP(&sys_reftime, &xpkt.reftime);
 	HTONL_FP(&peer->org, &xpkt.org);
 	HTONL_FP(&peer->rec, &xpkt.rec);
 
 	/*
-	 * Authenticate the packet if enabled and either configured or
-	 * the previous packet was authenticated. If for some reason the
-	 * key associated with the key identifier is not in the key
-	 * cache, then honk key zero.
+	 * If the received packet contains a MAC, the transmitted packet
+	 * is authenticated and contains a MAC. If not, the transmitted
+	 * packet is not authenticated.
+	 *
+	 * In the current I/O semantics the default interface is set
+	 * until after receiving a packet and setting the right
+	 * interface. So, the first packet goes out unauthenticated.
+	 * That's why the really icky test next is here.
 	 */
 	sendlen = LEN_PKT_NOMAC;
-	if (peer->flags & FLAG_AUTHENABLE) {
-		u_long xkeyid;
-		l_fp xmt_tx;
+	if (!(peer->flags & FLAG_AUTHENABLE)) {
+		get_systime(&peer->xmt);
+		HTONL_FP(&peer->xmt, &xpkt.xmt);
+		sendpkt(&peer->srcadr, peer->dstadr, peer->ttl, &xpkt,
+		    sendlen);
+		peer->sent++;
+#ifdef DEBUG
+		if (debug)
+			printf("transmit: at %ld %s->%s mode %d\n",
+			    current_time, ntoa(&peer->dstadr->sin),
+			    ntoa(&peer->srcadr), peer->hmode);
+#endif
+		return;
+	}
+
+	/*
+	 * The received packet contains a MAC, so the transmitted packet
+	 * must be authenticated. If autokey is enabled, fuss with the
+	 * various modes; otherwise, private key cryptography is used.
+	 */
+#ifdef AUTOKEY
+	if ((peer->flags & FLAG_SKEY)) {
+		u_int cmmd;
 
 		/*
-		 * Transmit encrypted packet compensated for the
-		 * encryption delay.
+		 * The Public Key Dance (PKD): Cryptographic credentials
+		 * are contained in extension fields, each including a
+		 * 4-octet length/code word followed by a 4-octet
+		 * association ID and optional additional data. Optional
+		 * data includes a 4-octet data length field followed by
+		 * the data itself. Request messages are sent from a
+		 * configured association; response messages can be sent
+		 * from a configured association or can take the fast
+		 * path without ever matching an association. Response
+		 * messages have the same code as the request, but have
+		 * a response bit and possibly an error bit set. In this
+		 * implementation, a message may contain no more than
+		 * one command and no more than one response.
+		 *
+		 * Cryptographic session keys include both a public and
+		 * a private componet. Request and response messages
+		 * using extension fields are always sent with the
+		 * private component set to zero. Packets without
+		 * extension fields indlude the private component when
+		 * the session key is generated.
 		 */
-#ifdef MD5
-		if (peer->flags & FLAG_SKEY) {
-
+		while (1) {
+		
 			/*
-			 * In autokey mode, allocate and initialize a
-			 * key list if not already done. Then, use the
-			 * list in inverse order, discarding keys once
-			 * used. Keep the latest key around until the
-			 * next one, so clients can use client/server
-			 * packets to compute propagation delay. Note we
-			 * have to wait until the receive side of the
-			 * socket is bound and the server address
-			 * confirmed.
+			 * Allocate and initialize a keylist if not
+			 * already done. Then, use the list in inverse
+			 * order, discarding keys once used. Keep the
+			 * latest key around until the next one, so
+			 * clients can use client/server packets to
+			 * compute propagation delay.
+			 *
+			 * Note that once a key is used from the list,
+			 * it is retained in the key cache until the
+			 * next key is used. This is to allow a client
+			 * to retrieve the encrypted session key
+			 * identifier to verify authenticity.
+			 *
+			 * If for some reason a key is no longer in the
+			 * key cache, a birthday has happened and the
+			 * pseudo-random sequence is probably broken. In
+			 * that case, purge the keylist and regenerate
+			 * it.
 			 */
-			if (ntohl(peer->dstadr->sin.sin_addr.s_addr) ==
-			    0 &&
-				ntohl(peer->dstadr->bcast.sin_addr.s_addr) == 0)
-				peer->keyid = 0;
-			else {
-				 if (peer->keylist == 0) {
-					make_keylist(peer);
-				} else {
-					authtrust(peer->keylist[peer->keynumber], 0);
-					if (peer->keynumber == 0)
-						make_keylist(peer);
-					else {
-						peer->keynumber--;
-						xkeyid = peer->keylist[peer->keynumber];
-						if (!authistrusted(xkeyid))
-							make_keylist(peer);
-					}
-				}
-				peer->keyid = peer->keylist[peer->keynumber];
-				xpkt.keyid1 = htonl(2 * sizeof(u_int32));
-				xpkt.keyid2 = htonl(sys_private);
-				sendlen += 2 * sizeof(u_int32);
-			}
+			if (peer->keynumber == 0)
+				make_keylist(peer, peer->dstadr);
+			else
+				peer->keynumber--;
+			xkeyid = peer->keylist[peer->keynumber];
+			if (authistrusted(xkeyid))
+				break;
+			else
+				key_expire(peer);
 		}
-#endif /* MD5 */
-		xkeyid = peer->keyid;
-		get_systime(&peer->xmt);
-		L_ADD(&peer->xmt, &sys_authdelay);
-		HTONL_FP(&peer->xmt, &xpkt.xmt);
-		sendlen += authencrypt(xkeyid, (u_int32 *)&xpkt,
-		    sendlen);
-		get_systime(&xmt_tx);
-		sendpkt(&peer->srcadr, find_rtt ? any_interface :
-		    peer->dstadr, ((peer->cast_flags & MDF_MCAST) &&
-		    !find_rtt) ? ((peer->cast_flags & MDF_ACAST) ? -7 :
-		    peer->ttl) : -7, &xpkt, sendlen);
+		peer->keyid = xkeyid;
+		switch (peer->hmode) {
 
 		/*
-		 * Calculate the encryption delay. Keep the minimum over
-		 * the latest two samples.
+		 * In broadcast mode the autokey values are required.
+		 * Send them when a new keylist is generated; otherwise,
+		 * send the association ID so the client can request
+		 * them at other times.
 		 */
-		L_SUB(&xmt_tx, &peer->xmt);
-		L_ADD(&xmt_tx, &sys_authdelay);
-		sys_authdly[1] = sys_authdly[0];
-		sys_authdly[0] = xmt_tx.l_uf;
-		if (sys_authdly[0] < sys_authdly[1])
-			sys_authdelay.l_uf = sys_authdly[0];
-		else
-			sys_authdelay.l_uf = sys_authdly[1];
-		peer->sent++;
-#ifdef DEBUG
-		if (debug)
-			printf(
-			    "transmit: at %ld to %s mode %d keyid %08lx index %d\n",
-			    current_time, ntoa(&peer->srcadr),
-			    peer->hmode, xkeyid, peer->keynumber);
-#endif
-	} else {
+		case MODE_BROADCAST:
+			if (peer->flags & FLAG_ASSOC)
+				cmmd = CRYPTO_AUTO | CRYPTO_RESP;
+			else
+				cmmd = CRYPTO_ASSOC | CRYPTO_RESP;
+			sendlen += crypto_xmit((u_int32 *)&xpkt,
+			    sendlen, cmmd, 0, peer->associd);
+			break;
+
 		/*
-		 * Transmit non-authenticated packet.
+		 * In symmetric modes the public key, leapsecond table,
+		 * agreement parameters and autokey values are required.
+ 		 *
+		 * 1. If a response is pending, always send it first.
+		 *
+		 * 2. Don't send anything except a public-key request
+		 *    until the public key has been stored. 
+		 *
+		 * 3. Once the public key has been stored, don't send
+		 *    anything except an agreement parameter request
+		 *    until the agreement parameters have been stored.
+		 *
+		 * 4. Once the argeement parameters have been stored,
+		 *    don't send anything except a public value request
+		 *    until the agreed key has been stored.
+		 *
+		 * 5. When the agreed key has been stored and the key
+		 *    list is regenerated, send the autokey values
+		 *    gratis unless they have already been sent.
 		 */
-		get_systime(&(peer->xmt));
-		HTONL_FP(&peer->xmt, &xpkt.xmt);
-		sendpkt(&(peer->srcadr), find_rtt ? any_interface :
-		    peer->dstadr, ((peer->cast_flags & MDF_MCAST) &&
-		    !find_rtt) ? ((peer->cast_flags & MDF_ACAST) ? -7 :
-		    peer->ttl) : -8, &xpkt, sendlen);
-		peer->sent++;
+		case MODE_ACTIVE:
+		case MODE_PASSIVE:
+#ifdef PUBKEY
+			if (peer->cmmd != 0)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, (peer->cmmd >> 16) |
+				    CRYPTO_RESP, peer->hcookie,
+				    peer->associd);
+			if (!peer->crypto)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_ASSOC,
+				    peer->hcookie, peer->assoc);
+			else if (!crypto_flags &&
+			    peer->pcookie.tstamp == 0 && sys_leap !=
+			    LEAP_NOTINSYNC)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_PRIV, peer->hcookie,
+				    peer->assoc);
+			else if (crypto_flags && peer->pubkey.ptr ==
+			    NULL)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_NAME, peer->hcookie,
+				    peer->assoc);
+			else if (peer->crypto & CRYPTO_FLAG_CERT)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_CERT, peer->hcookie,
+				    peer->assoc);
+			else if (crypto_flags && peer->crypto &
+			    CRYPTO_FLAG_DH && sys_leap !=
+			    LEAP_NOTINSYNC)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_DHPAR,
+				    peer->hcookie, peer->assoc);
+			else if (crypto_flags && peer->pcookie.tstamp ==
+			    0 && sys_leap != LEAP_NOTINSYNC)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_DH, peer->hcookie,
+				    peer->assoc);
+#else
+			if (peer->cmmd != 0)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, (peer->cmmd >> 16) |
+				    CRYPTO_RESP, peer->hcookie,
+				    peer->associd);
+			if (peer->pcookie.tstamp == 0 && sys_leap !=
+			    LEAP_NOTINSYNC)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_PRIV, peer->hcookie,
+				    peer->assoc);
+#endif /* PUBKEY */
+			else if (!(peer->flags & FLAG_AUTOKEY))
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_AUTO, peer->hcookie,
+				    peer->assoc);
+			else if ((peer->flags & FLAG_ASSOC) &&
+			    (peer->cmmd >> 16) != CRYPTO_AUTO)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_AUTO | CRYPTO_RESP,
+				    peer->hcookie, peer->associd);
+#ifdef PUBKEY
+			else if (peer->crypto & CRYPTO_FLAG_TAI)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_TAI, peer->hcookie,
+				    peer->assoc);
+#endif /* PUBKEY */
+			peer->cmmd = 0;
+			break;
+
+		/*
+		 * In client mode, the public key, host cookie and
+		 * autokey values are required. In broadcast client
+		 * mode, these values must be acquired during the
+		 * client/server exchange to avoid having to wait until
+		 * the next key list regeneration. Otherwise, the poor
+		 * dude may die a lingering death until becoming
+		 * unreachable and attempting rebirth. Note that we ask
+		 * for the cookie at each key list regeneration anyway.
+		 */
+		case MODE_CLIENT:
+			if (peer->cmmd != 0)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, (peer->cmmd >> 16) |
+				    CRYPTO_RESP, peer->hcookie,
+				    peer->associd);
+			if (!peer->crypto)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_ASSOC,
+				    peer->hcookie, peer->assoc);
+#ifdef PUBKEY
+			else if (crypto_flags && peer->pubkey.ptr ==
+			    NULL)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_NAME, peer->hcookie,
+				    peer->assoc);
+			else if (peer->crypto & CRYPTO_FLAG_CERT)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_CERT, peer->hcookie,
+				    peer->assoc);
+#endif /* PUBKEY */
+			else if (peer->pcookie.tstamp == 0)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_PRIV, peer->hcookie,
+				    peer->assoc);
+			else if (!(peer->flags & FLAG_AUTOKEY) &&
+			    (peer->cast_flags & MDF_BCLNT))
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_AUTO, peer->hcookie,
+				    peer->assoc);
+#ifdef PUBKEY
+			else if (peer->crypto & CRYPTO_FLAG_TAI)
+				sendlen += crypto_xmit((u_int32 *)&xpkt,
+				    sendlen, CRYPTO_TAI, peer->hcookie,
+				    peer->assoc);
+#endif /* PUBKEY */
+			peer->cmmd = 0;
+			break;
+		}
+
+		/*
+		 * If extension fields are present, we must use a
+		 * private value of zero and force min poll interval.  
+		 * Most intricate.
+		 */
+		if (sendlen > LEN_PKT_NOMAC)
+			session_key(&peer->dstadr->sin, &peer->srcadr,
+			    xkeyid, 0, 2);
+	} 
+#endif /* AUTOKEY */
+	xkeyid = peer->keyid;
+	get_systime(&peer->xmt);
+	L_ADD(&peer->xmt, &sys_authdelay);
+	HTONL_FP(&peer->xmt, &xpkt.xmt);
+	authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen);
+	if (authlen == 0) {
+		msyslog(LOG_NOTICE,
+			"transmit: no encryption key found");
+		peer->flash |= TEST4 | TEST5;
+		return;
+	}
+	sendlen += authlen;
+#ifdef AUTOKEY
+	if (xkeyid > NTP_MAXKEY)
+		authtrust(xkeyid, 0);
+#endif /* AUTOKEY */
+	get_systime(&xmt_tx);
+	if (sendlen > sizeof(xpkt)) {
+		msyslog(LOG_ERR, "buffer overflow %u", sendlen);
+		exit(-1);
+	}
+	sendpkt(&peer->srcadr, peer->dstadr, peer->ttl, &xpkt, sendlen);
+
+	/*
+	 * Calculate the encryption delay. Keep the minimum over
+	 * the latest two samples.
+	 */
+	L_SUB(&xmt_tx, &peer->xmt);
+	L_ADD(&xmt_tx, &sys_authdelay);
+	sys_authdly[1] = sys_authdly[0];
+	sys_authdly[0] = xmt_tx.l_uf;
+	if (sys_authdly[0] < sys_authdly[1])
+		sys_authdelay.l_uf = sys_authdly[0];
+	else
+		sys_authdelay.l_uf = sys_authdly[1];
+	peer->sent++;
+#ifdef AUTOKEY
 #ifdef DEBUG
-		if (debug)
-			printf("transmit: at %ld to %s mode %d\n",
-				current_time, ntoa(&peer->srcadr),
-				peer->hmode);
+	if (debug)
+		printf(
+		    "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d index %d\n",
+		    current_time, ntoa(&peer->dstadr->sin),
+		    ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen,
+		    authlen, peer->keynumber);
 #endif
-	}
+#else
+#ifdef DEBUG
+	if (debug)
+		printf(
+		    "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n",
+		    current_time, ntoa(&peer->dstadr->sin),
+		    ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen,
+		    authlen);
+#endif
+#endif /* AUTOKEY */
 }
 
+
 /*
- * fast_xmit - Send packet for nonpersistent association.
+ * fast_xmit - Send packet for nonpersistent association. Note that
+ * neither the source or destination can be a broadcast address.
  */
 static void
 fast_xmit(
 	struct recvbuf *rbufp,	/* receive packet pointer */
 	int xmode,		/* transmit mode */
-	u_long xkeyid		/* transmit key ID */
+	keyid_t xkeyid,		/* transmit key ID */
+	int mask		/* restrict mask */
 	)
 {
-	struct pkt xpkt;
-	struct pkt *rpkt;
-	int sendlen;
-	l_fp xmt_ts;
+	struct pkt xpkt;	/* transmit packet structure */
+	struct pkt *rpkt;	/* receive packet structure */
+	l_fp xmt_ts;		/* transmit timestamp */
+	l_fp xmt_tx;		/* transmit timestamp after authent */
+	int sendlen, authlen;
 
 	/*
-	 * Initialize transmit packet header fields in the receive
-	 * buffer provided. We leave some fields intact as received.
+	 * Initialize transmit packet header fields from the receive
+	 * buffer provided. We leave some fields intact as received. If
+	 * the gazinta was from a multicast address, the gazouta must go
+	 * out another way.
 	 */
 	rpkt = &rbufp->recv_pkt;
-	xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap,
-		PKT_VERSION(rpkt->li_vn_mode), xmode);
-	xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
+	if (rbufp->dstadr->flags & INT_MULTICAST)
+		rbufp->dstadr = findinterface(&rbufp->recv_srcadr);
+
+	/*
+	 * If the caller is restricted, return a kiss-of-death packet;
+	 * otherwise, smooch politely.
+	 */
+	if (mask & (RES_DONTSERVE | RES_LIMITED)) {
+		if (!(mask & RES_DEMOBILIZE)) {
+			return;
+		} else {
+			xpkt.li_vn_mode =
+			    PKT_LI_VN_MODE(LEAP_NOTINSYNC,
+			    PKT_VERSION(rpkt->li_vn_mode), xmode);
+			xpkt.stratum = STRATUM_UNSPEC;
+			memcpy(&xpkt.refid, "DENY", 4);
+		}
+	} else {
+		xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap,
+		    PKT_VERSION(rpkt->li_vn_mode), xmode);
+		xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
+		xpkt.refid = sys_refid;
+	}
 	xpkt.ppoll = rpkt->ppoll;
 	xpkt.precision = sys_precision;
 	xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
-	xpkt.rootdispersion = HTONS_FP(DTOUFP(sys_rootdispersion +
-		LOGTOD(sys_precision)));
-	xpkt.refid = sys_refid;
+	xpkt.rootdispersion =
+	    HTONS_FP(DTOUFP(sys_rootdispersion));
 	HTONL_FP(&sys_reftime, &xpkt.reftime);
 	xpkt.org = rpkt->xmt;
 	HTONL_FP(&rbufp->recv_time, &xpkt.rec);
-	sendlen = LEN_PKT_NOMAC;
-	if (rbufp->recv_length > sendlen) {
-		l_fp xmt_tx;
 
-		/*
-		 * Transmit encrypted packet compensated for the
-		 * encryption delay.
-		 */
-		if (xkeyid > NTP_MAXKEY) {
-			xpkt.keyid1 = htonl(2 * sizeof(u_int32));
-			xpkt.keyid2 = htonl(sys_private);
-			sendlen += 2 * sizeof(u_int32);
-		}
+	/*
+	 * If the received packet contains a MAC, the transmitted packet
+	 * is authenticated and contains a MAC. If not, the transmitted
+	 * packet is not authenticated.
+	 */
+	sendlen = LEN_PKT_NOMAC;
+	if (rbufp->recv_length == sendlen) {
 		get_systime(&xmt_ts);
-		L_ADD(&xmt_ts, &sys_authdelay);
 		HTONL_FP(&xmt_ts, &xpkt.xmt);
-		sendlen += authencrypt(xkeyid, (u_int32 *)&xpkt,
+		sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt,
 		    sendlen);
-		get_systime(&xmt_tx);
-		sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, -9, &xpkt,
-		    sendlen);
-
-		/*
-		 * Calculate the encryption delay. Keep the minimum over
-		 * the latest two samples.
-		 */
-		L_SUB(&xmt_tx, &xmt_ts);
-		L_ADD(&xmt_tx, &sys_authdelay);
-		sys_authdly[1] = sys_authdly[0];
-		sys_authdly[0] = xmt_tx.l_uf;
-		if (sys_authdly[0] < sys_authdly[1])
-			sys_authdelay.l_uf = sys_authdly[0];
-		else
-			sys_authdelay.l_uf = sys_authdly[1];
 #ifdef DEBUG
 		if (debug)
-			printf(
-			    "transmit: at %ld to %s mode %d keyid %08lx\n",
-				current_time, ntoa(&rbufp->recv_srcadr),
-				xmode, xkeyid);
+			printf("transmit: at %ld %s->%s mode %d\n",
+			    current_time, ntoa(&rbufp->dstadr->sin),
+			    ntoa(&rbufp->recv_srcadr), xmode);
 #endif
-	} else {
+		return;
+	}
+
+	/*
+	 * The received packet contains a MAC, so the transmitted packet
+	 * must be authenticated. For private-key cryptography, use the
+	 * predefined private keys to generate the cryptosum. For
+	 * autokey cryptography, use the server private value to
+	 * generate the cookie, which is unique for every source-
+	 * destination-key ID combination.
+	 */
+#ifdef AUTOKEY
+	if (xkeyid > NTP_MAXKEY) {
+		keyid_t cookie;
+		u_int code, associd;
 
 		/*
-		 * Transmit non-authenticated packet.
+		 * The only way to get here is a reply to a legitimate
+		 * client request message, so the mode must be
+		 * MODE_SERVER. If an extension field is present, there
+		 * can be only one and that must be a command. Do what
+		 * needs, but with private value of zero so the poor
+		 * jerk can decode it. If no extension field is present,
+		 * use the cookie to generate the session key.
 		 */
-		get_systime(&xmt_ts);
-		HTONL_FP(&xmt_ts, &xpkt.xmt);
-		sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, -10, &xpkt,
-			sendlen);
+		code = (htonl(rpkt->exten[0]) >> 16) | CRYPTO_RESP;
+		cookie = session_key(&rbufp->recv_srcadr,
+		    &rbufp->dstadr->sin, 0, sys_private, 0);
+		associd = htonl(rpkt->exten[1]);
+		if (rbufp->recv_length >= sendlen + MAX_MAC_LEN + 2 *
+		    sizeof(u_int32)) {
+			session_key(&rbufp->dstadr->sin,
+			    &rbufp->recv_srcadr, xkeyid, 0, 2);
+			sendlen += crypto_xmit((u_int32 *)&xpkt,
+			    sendlen, code, cookie, associd);
+		} else {
+			session_key(&rbufp->dstadr->sin,
+			    &rbufp->recv_srcadr, xkeyid, cookie, 2);
+		}
+	}
+#endif /* AUTOKEY */
+	get_systime(&xmt_ts);
+	L_ADD(&xmt_ts, &sys_authdelay);
+	HTONL_FP(&xmt_ts, &xpkt.xmt);
+	authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen);
+	sendlen += authlen;
+#ifdef AUTOKEY
+	if (xkeyid > NTP_MAXKEY)
+		authtrust(xkeyid, 0);
+#endif /* AUTOKEY */
+	get_systime(&xmt_tx);
+	if (sendlen > sizeof(xpkt)) {
+		msyslog(LOG_ERR, "buffer overflow %u", sendlen);
+		exit(-1);
+	}
+	sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt, sendlen);
+
+	/*
+	 * Calculate the encryption delay. Keep the minimum over the
+	 * latest two samples.
+	 */
+	L_SUB(&xmt_tx, &xmt_ts);
+	L_ADD(&xmt_tx, &sys_authdelay);
+	sys_authdly[1] = sys_authdly[0];
+	sys_authdly[0] = xmt_tx.l_uf;
+	if (sys_authdly[0] < sys_authdly[1])
+		sys_authdelay.l_uf = sys_authdly[0];
+	else
+		sys_authdelay.l_uf = sys_authdly[1];
 #ifdef DEBUG
-		if (debug)
-			printf("transmit: at %ld to %s mode %d\n",
-				current_time, ntoa(&rbufp->recv_srcadr),
-				xmode);
+	if (debug)
+		printf(
+		    "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n",
+		    current_time, ntoa(&rbufp->dstadr->sin),
+		    ntoa(&rbufp->recv_srcadr), xmode, xkeyid, sendlen,
+		    authlen);
 #endif
-	}
 }
 
-#ifdef MD5
+
+#ifdef AUTOKEY
 /*
- * Compute key list
+ * key_expire - purge the key list
  */
-static void
-make_keylist(
-	struct peer *peer
+void
+key_expire(
+	struct peer *peer	/* peer structure pointer */
 	)
 {
 	int i;
-	u_long keyid;
-	u_long ltemp;
 
-	/*
-	 * Allocate the key list if necessary.
-	 */
-	if (peer->keylist == 0)
-		peer->keylist = (u_long *)emalloc(sizeof(u_long) *
-		    NTP_MAXSESSION);
-
-	/*
-	 * Generate an initial key ID which is unique and greater than
-	 * NTP_MAXKEY.
-	 */
-	while (1) {
-		keyid = (u_long)RANDOM & 0xffffffff;
-		if (keyid <= NTP_MAXKEY)
-			continue;
-		if (authhavekey(keyid))
-			continue;
-		break;
-	}
-
-	/*
-	 * Generate up to NTP_MAXSESSION session keys. Stop if the
-	 * next one would not be unique or not a session key ID or if
-	 * it would expire before the next poll.
-	 */
-	ltemp = sys_automax;
-	for (i = 0; i < NTP_MAXSESSION; i++) {
-		peer->keylist[i] = keyid;
-		peer->keynumber = i;
-		keyid = session_key(
-		    ntohl(peer->dstadr->sin.sin_addr.s_addr),
-		    (peer->hmode == MODE_BROADCAST || (peer->flags &
-		    FLAG_MCAST2)) ?
-		    ntohl(peer->dstadr->bcast.sin_addr.s_addr):
-		    ntohl(peer->srcadr.sin_addr.s_addr), keyid, ltemp);
-		ltemp -= 1 << peer->hpoll;
-		if (auth_havekey(keyid) || keyid <= NTP_MAXKEY ||
-		    ltemp <= (1 << (peer->hpoll + 1)))
-			break;
+ 	if (peer->keylist != NULL) {
+		for (i = 0; i <= peer->keynumber; i++)
+			authtrust(peer->keylist[i], 0);
+		free(peer->keylist);
+		peer->keylist = NULL;
 	}
+	peer->keynumber = peer->sndauto.seq = 0;
+#ifdef DEBUG
+	if (debug)
+		printf("key_expire: at %lu\n", current_time);
+#endif
 }
-#endif /* MD5 */
+#endif /* AUTOKEY */
 
 /*
  * Find the precision of this particular machine
@@ -2033,19 +2601,17 @@ init_proto(void)
 	sys_leap = LEAP_NOTINSYNC;
 	sys_stratum = STRATUM_UNSPEC;
 	sys_precision = (s_char)default_get_precision();
+	sys_jitter = LOGTOD(sys_precision);
 	sys_rootdelay = 0;
 	sys_rootdispersion = 0;
 	sys_refid = 0;
 	L_CLR(&sys_reftime);
-	sys_peer = 0;
+	sys_peer = NULL;
+	sys_survivors = 0;
 	get_systime(&dummy);
 	sys_bclient = 0;
 	sys_bdelay = DEFBROADDELAY;
-#if defined(DES) || defined(MD5)
 	sys_authenticate = 1;
-#else
-	sys_authenticate = 0;
-#endif
 	L_CLR(&sys_authdelay);
 	sys_authdly[0] = sys_authdly[1] = 0;
 	sys_stattime = 0;
@@ -2057,7 +2623,9 @@ init_proto(void)
 	sys_processed = 0;
 	sys_badauth = 0;
 	sys_manycastserver = 0;
+#ifdef AUTOKEY
 	sys_automax = 1 << NTP_AUTOMAX;
+#endif /* AUTOKEY */
 
 	/*
 	 * Default these to enable
@@ -2066,11 +2634,12 @@ init_proto(void)
 #ifndef KERNEL_FLL_BUG
 	kern_enable = 1;
 #endif
-	msyslog(LOG_DEBUG, "kern_enable is %d", kern_enable);
+	pps_enable = 0;
 	stats_control = 1;
 
 	/*
-	 * Some system clocks should only be adjusted in 10ms increments.
+	 * Some system clocks should only be adjusted in 10ms
+	 * increments.
 	 */
 #if defined RELIANTUNIX_CLOCK
 	systime_10ms_ticks = 1;		  /* Reliant UNIX */
@@ -2176,6 +2745,24 @@ proto_config(
 		sys_authenticate = (int)value;
 		break;
 
+	case PROTO_PPS:
+
+		/*
+		 * Turn on/off PPS discipline
+		 */
+		pps_enable = (int)value;
+		break;
+
+#ifdef REFCLOCK
+	case PROTO_CAL:
+
+		/*
+		 * Turn on/off refclock calibrate
+		 */
+		cal_enable = (int)value;
+		break;
+#endif
+
 	default:
 
 		/*