[Git][NTPsec/ntpsec][master] 5 commits: Add ntp_random64

Hal Murray gitlab at mg.gitlab.com
Wed Jul 11 04:28:51 UTC 2018


Hal Murray pushed to branch master at NTPsec / ntpsec


Commits:
3aca5b79 by Hal Murray at 2018-07-09T01:12:02Z
Add ntp_random64

- - - - -
ec804bc4 by Hal Murray at 2018-07-09T05:50:36Z
Cleanup peer_xmit - should be no visible change

- - - - -
a745d41a by Hal Murray at 2018-07-09T07:25:23Z
First cut at data minimization
  Still sends valid time in pkt->xmt
  Other fields are hidden as per draft spec.

- - - - -
60fe3b92 by Hal Murray at 2018-07-09T11:18:40Z
Rest of data minimization
  randomize transmit timestamp

- - - - -
fb105e4e by Hal Murray at 2018-07-10T10:46:48Z
Update NEWS: CMAC authentication, data minimization

- - - - -


6 changed files:

- NEWS
- include/ntp.h
- libntp/ntp_random.c
- ntpd/ntp_proto.c
- ntpd/ntp_refclock.c
- ntpd/ntp_util.c


Changes:

=====================================
NEWS
=====================================
@@ -12,6 +12,12 @@ on user-visible changes.
 
 == Repository Head ==
 
+Use data minimization on client requests
+  https://datatracker.ietf.org/doc/draft-ietf-ntp-data-minimization/
+
+Support AES-128-CMAC for authentication
+  https://datatracker.ietf.org/doc/draft-ietf-ntp-mac/
+
 == 2018-06-11: 1.1.1 ==
 
 Log timestamps now include the year.  This is useful when


=====================================
include/ntp.h
=====================================
@@ -16,6 +16,7 @@
 #include "ntp_net.h"
 
 extern int32_t ntp_random (void);
+extern uint64_t ntp_random64 (void);
 
 /*
  * Calendar arithmetic - contributed by G. Healton
@@ -278,7 +279,8 @@ struct peer {
 	l_fp	rec;		/* receive time stamp */
 	l_fp	xmt;		/* transmit time stamp */
 	l_fp	dst;		/* destination timestamp */
-	l_fp	org;		/* origin timestamp */
+	l_fp	org_ts;		/* origin real-timestamp */
+	l_fp	org_rand;	/* origin pseudo-timestamp */
 	double	offset;		/* peer clock offset */
 	double	delay;		/* peer roundtrip delay */
 	double	jitter;		/* peer jitter (squares) */


=====================================
libntp/ntp_random.c
=====================================
@@ -29,3 +29,17 @@ ntp_random(void)
 	}
 	return rnd;
 }
+
+uint64_t
+ntp_random64(void)
+{
+        int err;
+        uint64_t rnd;
+        err = RAND_bytes((unsigned char *)&rnd, sizeof(rnd));
+        if (1 != err) {
+                msyslog(LOG_ERR, "ERR: ntp_random - RAND_bytes failed");
+          exit(1);
+        }
+        return rnd;
+}
+


=====================================
ntpd/ntp_proto.c
=====================================
@@ -494,7 +494,7 @@ handle_procpkt(
 			peer->flash |= BOGON3;
 			peer->bogusorg++;
 			return;
-		} else if(rbufp->pkt.org != peer->org) {
+		} else if(rbufp->pkt.org != peer->org_rand) {
 			peer->flash |= BOGON2;
 			peer->bogusorg++;
 			return;
@@ -550,9 +550,9 @@ handle_procpkt(
 	    scalbn((double)(rbufp->pkt.xmt - rbufp->recv_time), -32) :
 	    -scalbn((double)(rbufp->recv_time - rbufp->pkt.xmt), -32);
 	const double t21 =
-	    (rbufp->pkt.rec >= peer->org) ?
-	    scalbn((double)(rbufp->pkt.rec - peer->org), -32) :
-	    -scalbn((double)(peer->org - rbufp->pkt.rec), -32);
+	    (rbufp->pkt.rec >= peer->org_ts) ?
+	    scalbn((double)(rbufp->pkt.rec - peer->org_ts), -32) :
+	    -scalbn((double)(peer->org_ts - rbufp->pkt.rec), -32);
 	const double theta = (t21 + t34) / 2.;
 	const double delta = fabs(t21 - t34);
 	const double epsilon = LOGTOD(sys_vars.sys_precision) +
@@ -2049,87 +2049,82 @@ root_distance(
 
 
 /*
- * peer_xmit - send packet for persistent association.
+ * peer_xmit - send client-mode packet for persistent association.
  */
 static void
 peer_xmit(
 	struct peer *peer	/* peer structure pointer */
 	)
 {
-	struct pkt xpkt;	/* transmit packet */
-	size_t	sendlen, authlen;
-	auth_info *auth;	/* !NULL for authentication */
-	l_fp	xmt_tx;
+	struct		pkt xpkt;	/* transmit packet */
+	unsigned int	sendlen;
 
-	if (!peer->dstadr)	/* drop peers without interface */
+	if (!peer->dstadr)		/* drop peers without interface */
 		return;
 
-	xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_vars.sys_leap, peer->cfg.version,
-	    peer->hmode);
-	xpkt.stratum = STRATUM_TO_PKT(sys_vars.sys_stratum);
-	xpkt.ppoll = peer->hpoll;
-	xpkt.precision = sys_vars.sys_precision;
-	xpkt.refid = sys_vars.sys_refid;
-	xpkt.rootdelay = HTONS_FP(DTOUFP(sys_vars.sys_rootdelay));
-	xpkt.rootdisp =	 HTONS_FP(DTOUFP(sys_vars.sys_rootdisp));
-	xpkt.reftime = htonl_fp(sys_vars.sys_reftime);
-	xpkt.org = htonl_fp(peer->xmt);
-	xpkt.rec = htonl_fp(peer->dst);
-
-	/*
-	 * If the peer (aka server) was configured with a key, authenticate
-	 * the packet.  Else, the packet is not authenticated.
-	 */
 	sendlen = LEN_PKT_NOMAC;
-	if (peer->cfg.peerkey == 0) {
-		/*
-		 * Transmit a-priori timestamps.  This is paired with
-		 * a later call used to record transmission time.
+	if (NTP_VERSION == peer->cfg.version) {
+		/* Hide most of info for privacy
+		 * RFC in progress - draft-ietf-ntp-data-minimization, 2018-Jul-07
 		 */
-		get_systime(&xmt_tx);
-		peer->org = xmt_tx;
-		xpkt.xmt = htonl_fp(xmt_tx);
-		sendpkt(&peer->srcadr, peer->dstadr, &xpkt, (int)sendlen);
-		peer->sent++;
-		peer->outcount++;
-		peer->throttle += (1 << peer->cfg.minpoll) - 2;
-
-		DPRINT(1, ("transmit: at %u %s->%s mode %d len %zu\n",
-			   current_time, peer->dstadr ?
-			   socktoa(&peer->dstadr->sin) : "-",
-			   socktoa(&peer->srcadr), peer->hmode, sendlen));
-		return;
+		xpkt.li_vn_mode = PKT_LI_VN_MODE(
+			LEAP_NOWARNING, peer->cfg.version, MODE_CLIENT);
+		xpkt.stratum = 0;
+		xpkt.ppoll = 0;
+		xpkt.precision = 0x20;
+		xpkt.refid = 0;
+		xpkt.rootdelay = 0;
+		xpkt.rootdisp =	0;
+		xpkt.reftime = htonl_fp(0);
+		xpkt.org = htonl_fp(0);
+		xpkt.rec = htonl_fp(0);
+		peer->org_rand = ntp_random64();
+		get_systime(&peer->org_ts);	/* as late as possible */
+	} else {
+		xpkt.li_vn_mode = PKT_LI_VN_MODE(
+			sys_vars.sys_leap, peer->cfg.version, peer->hmode);
+		xpkt.stratum = STRATUM_TO_PKT(sys_vars.sys_stratum);
+		xpkt.ppoll = peer->hpoll;
+		xpkt.precision = sys_vars.sys_precision;
+		xpkt.refid = sys_vars.sys_refid;
+		xpkt.rootdelay = HTONS_FP(DTOUFP(sys_vars.sys_rootdelay));
+		xpkt.rootdisp =	 HTONS_FP(DTOUFP(sys_vars.sys_rootdisp));
+		xpkt.reftime = htonl_fp(sys_vars.sys_reftime);
+		xpkt.org = htonl_fp(peer->xmt);
+		xpkt.rec = htonl_fp(peer->dst);
+		get_systime(&peer->org_ts);	/* as late as possible */
+		peer->org_rand = peer->org_ts;
 	}
 
-	/*
-	 * Authentication is enabled, so the transmitted packet must be
-	 * authenticated.
-`	 */
+	xpkt.xmt = htonl_fp(peer->org_rand);	/* out in xmt, back in org */
+
 
 	/*
-	 * Transmit a-priori timestamps
+	 * If the peer (aka server) was configured with a key, authenticate
+	 * the packet.  Else, the packet is not authenticated.
 	 */
-	get_systime(&xmt_tx);
-	peer->org = xmt_tx;
-	xpkt.xmt = htonl_fp(xmt_tx);
-	auth = authlookup(peer->cfg.peerkey, true);
-	if (NULL == auth) {
-		report_event(PEVNT_AUTH, peer, "no key");
-		peer->flash |= BOGON5;		/* auth error */
-		peer->badauth++;
-		return;
-	}
-	authlen = (size_t)authencrypt(auth, (uint32_t *)&xpkt, (int)sendlen);
-	sendlen += authlen;
-	if (sendlen > sizeof(xpkt)) {
-		msyslog(LOG_ERR, "PROTO: buffer overflow %zu", sendlen);
-		exit(1);
+	if (0 != peer->cfg.peerkey) {
+		auth_info *auth = authlookup(peer->cfg.peerkey, true);
+		if (NULL == auth) {
+			report_event(PEVNT_AUTH, peer, "no key");
+			peer->flash |= BOGON5;		/* auth error */
+			peer->badauth++;
+			return;
+		}
+		/* Maybe bump peer->org_ts to account for crypto time */
+		sendlen += authencrypt(auth, (uint32_t *)&xpkt, sendlen);
+		if (sendlen > sizeof(xpkt)) {
+			msyslog(LOG_ERR, "PROTO: buffer overflow %u", sendlen);
+			exit(1);
+		}
 	}
-	sendpkt(&peer->srcadr, peer->dstadr, &xpkt, (int)sendlen);
+
+	sendpkt(&peer->srcadr, peer->dstadr, &xpkt, sendlen);
+
 	peer->sent++;
         peer->outcount++;
 	peer->throttle += (1 << peer->cfg.minpoll) - 2;
-	DPRINT(1, ("transmit: at %u %s->%s mode %d keyid %08x len %zu\n",
+	DPRINT(1, ("transmit: at %u %s->%s mode %d keyid %08x len %u\n",
 		   current_time, peer->dstadr ?
 		   socktoa(&peer->dstadr->sin) : "-",
 		   socktoa(&peer->srcadr), peer->hmode,


=====================================
ntpd/ntp_refclock.c
=====================================
@@ -532,7 +532,7 @@ refclock_receive(
 	}
 	peer->reach |= 1;
 	peer->reftime = pp->lastref;
-	peer->org = pp->lastrec;
+	peer->org_ts = pp->lastrec;
 	peer->rootdisp = pp->disp;
 	get_systime(&peer->dst);
 	if (!refclock_sample(pp))


=====================================
ntpd/ntp_util.c
=====================================
@@ -540,7 +540,7 @@ record_raw_stats(
 {
 	struct timespec	now;
 	const sockaddr_u *dstaddr = peer->dstadr ? &peer->dstadr->sin : NULL;
-	l_fp	t1 = peer->org;		/* originate timestamp */
+	l_fp	t1 = peer->org_ts;	/* originate timestamp */
 	l_fp	t2 = peer->rec;		/* receive timestamp */
 	l_fp	t3 = peer->xmt;		/* transmit timestamp */
 	l_fp	t4 = peer->dst;		/* destination timestamp */



View it on GitLab: https://gitlab.com/NTPsec/ntpsec/compare/e62391bf7447b1086d9e45a2aac26d995967bcff...fb105e4eb50f2b6287568ec08f8d16e6cd4d53ab

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View it on GitLab: https://gitlab.com/NTPsec/ntpsec/compare/e62391bf7447b1086d9e45a2aac26d995967bcff...fb105e4eb50f2b6287568ec08f8d16e6cd4d53ab
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