noise: redesign preshared key mode

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

contrib/external-tests/go/main.go

@@ -37,16 +37,17 @@ func ipChecksum(buf []byte) uint16 {
 func main() {
 	ourPrivate, _ := base64.StdEncoding.DecodeString("WAmgVYXkbT2bCtdcDwolI88/iVi/aV3/PHcUBTQSYmo=")
 	ourPublic, _ := base64.StdEncoding.DecodeString("K5sF9yESrSBsOXPd6TcpKNgqoy1Ik3ZFKl4FolzrRyI=")
-	preshared, _ := base64.StdEncoding.DecodeString("FpCyhws9cxwWoV4xELtfJvjJN+zQVRPISllRWgeopVE=")
 	theirPublic, _ := base64.StdEncoding.DecodeString("qRCwZSKInrMAq5sepfCdaCsRJaoLe5jhtzfiw7CjbwM=")
+	preshared, _ := base64.StdEncoding.DecodeString("FpCyhws9cxwWoV4xELtfJvjJN+zQVRPISllRWgeopVE=")
 	cs := noise.NewCipherSuite(noise.DH25519, noise.CipherChaChaPoly, noise.HashBLAKE2s)
 	hs := noise.NewHandshakeState(noise.Config{
 		CipherSuite:   cs,
 		Random:        rand.Reader,
 		Pattern:       noise.HandshakeIK,
 		Initiator:     true,
-		Prologue:      []byte("WireGuard v0 zx2c4 Jason@zx2c4.com"),
+		Prologue:      []byte("WireGuard v1 zx2c4 Jason@zx2c4.com"),
 		PresharedKey:  preshared,
+		PresharedKeyPlacement: 2,
 		StaticKeypair: noise.DHKey{Private: ourPrivate, Public: ourPublic},
 		PeerStatic:    theirPublic,
 	})
@@ -68,8 +69,10 @@ func main() {
 	initiationPacket[3] = 0	// Reserved
 	binary.LittleEndian.PutUint32(initiationPacket[4:], 28) // Sender index: 28 (arbitrary)
 	initiationPacket, _, _ = hs.WriteMessage(initiationPacket, tai64n)
-	hasher, _ := blake2s.New(&blake2s.Config{Size: 16, Key: preshared})
+	hasher, _ := blake2s.New(&blake2s.Config{Size: 32})
+	hasher.Write([]byte("mac1----"))
 	hasher.Write(theirPublic)
+	hasher, _ = blake2s.New(&blake2s.Config{Size: 16, Key: hasher.Sum(nil)})
 	hasher.Write(initiationPacket)
 	initiationPacket = append(initiationPacket, hasher.Sum(nil)[:16]...)
 	initiationPacket = append(initiationPacket, make([]byte, 16)...)

contrib/external-tests/haskell/src/Main.hs

@@ -34,7 +34,7 @@ w :: PublicKey Curve25519
   -> IO ()
 w theirPub (Plaintext myPSK) sock addr msg = do
   let x      = "\x01\x00\x00\x00\x00\x00" `mappend` msg
-      mac    = hash 16 myPSK (sbToBS' (curvePubToBytes theirPub) `mappend` sbToBS' x)
+      mac    = hash 16 myPSK (sbToBS' (curvePubToBytes theirPub) `mappend` sbToBS' x) -- TODO: this should actually be blake2s(key=blake2s("mac1----" || theirPub), payload=blah)
   void $ NBS.sendTo sock (x `mappend` mac `mappend` replicate 16 '\0') addr
 
 r :: MVar ByteString -> Socket -> IO ByteString
@@ -63,8 +63,8 @@ main = do
       serverkey' = curveBytesToPub   . bsToSB' . either undefined id . B64.decode . pack $ serverkey :: PublicKey Curve25519
       psk'       = Plaintext . bsToSB' . either undefined id . B64.decode . pack $ psk
       hs         = handshakeState $ HandshakeStateParams
-                   noiseIK
+                   noiseIK -- TODO: specify psk2 mode
-                   "WireGuard v0 zx2c4 Jason@zx2c4.com"
+                   "WireGuard v1 zx2c4 Jason@zx2c4.com"
                    (Just psk')
                    (Just mykey')
                    Nothing

contrib/external-tests/rust/src/main.rs

@@ -39,11 +39,12 @@ fn main() {
 	owner.set_rs(&their_public);
 	let mut cipherstate1 : CipherState<CipherChaChaPoly> = Default::default();
         let mut cipherstate2 : CipherState<CipherChaChaPoly> = Default::default();
-	let mut handshake = HandshakeState::new_from_owner(&mut owner, true, HandshakePattern::IK, "WireGuard v0 zx2c4 Jason@zx2c4.com".as_bytes(), Some(&my_preshared[..]), &mut cipherstate1, &mut cipherstate2);
+	//TODO: specify psk2 mode
+	let mut handshake = HandshakeState::new_from_owner(&mut owner, true, HandshakePattern::IK, "WireGuard v1 zx2c4 Jason@zx2c4.com".as_bytes(), Some(&my_preshared[..]), &mut cipherstate1, &mut cipherstate2);
 
 	let now = time::get_time();
 	let mut tai64n = [0; 12];
-	BigEndian::write_i64(&mut tai64n[0..], 4611686018427387914ULL + now.sec);
+	BigEndian::write_i64(&mut tai64n[0..], 4611686018427387914 + now.sec);
 	BigEndian::write_i32(&mut tai64n[8..], now.nsec);
 	let mut initiation_packet = [0; 148];
 	initiation_packet[0] = 1; /* Type: Initiation */
@@ -52,11 +53,13 @@ fn main() {
 	initiation_packet[3] = 0; /* Reserved */
 	LittleEndian::write_u32(&mut initiation_packet[4..], 28); /* Sender index: 28 (arbitrary) */
 	handshake.write_message(&tai64n, &mut initiation_packet[8..]);
-	let mut mac_material = [0; 148];
+	let mut mac_key_input = [0; 40];
-	memcpy(&mut mac_material, &their_public);
+	let mut mac_key = [0; 32];
-	memcpy(&mut mac_material[32..], &initiation_packet[0..116]);
+	memcpy(&mut mac_key_input, b"mac1----");
+	memcpy(&mut mac_key_input[8..], &their_public);
+	Blake2s::blake2s(&mut mac_key, &mac_key_input, &[0; 0]);
 	let mut mac = [0; 16];
-	Blake2s::blake2s(&mut mac, &mac_material, &my_preshared);
+	Blake2s::blake2s(&mut mac, &initiation_packet[0..116], &mac_key);
 	memcpy(&mut initiation_packet[116..], &mac);
 	socket.send_to(&initiation_packet, &send_addr).unwrap();
 

contrib/json/wg-json

@@ -9,20 +9,20 @@ while read -r -d $'\t' device; do
 	if [[ $device != "$last_device" ]]; then
 		[[ -z $last_device ]] && printf '\n' || printf '%s,\n' "$end"
 		last_device="$device"
-		read -r private_key public_key preshared_key listen_port fwmark
+		read -r private_key public_key listen_port fwmark
 		printf '\t"%s": {' "$device"
 		delim=$'\n'
 		[[ $private_key == "(none)" ]] || { printf '%s\t\t"privateKey": "%s"' "$delim" "$private_key"; delim=$',\n'; }
 		[[ $public_key == "(none)" ]] || { printf '%s\t\t"publicKey": "%s"' "$delim" "$public_key"; delim=$',\n'; }
-		[[ $preshared_key == "(none)" ]] || { printf '%s\t\t"presharedKey": "%s"' "$delim" "$preshared_key"; delim=$',\n'; }
 		[[ $listen_port == "0" ]] || { printf '%s\t\t"listenPort": %u' "$delim" $(( $listen_port )); delim=$',\n'; }
 		[[ $fwmark == "off" ]] || { printf '%s\t\t"fwmark": %u' "$delim" $(( $fwmark )); delim=$',\n'; }
 		printf '%s\t\t"peers": {' "$delim"; end=$'\n\t\t}\n\t}'
 		delim=$'\n'
 	else
-		read -r public_key endpoint allowed_ips latest_handshake transfer_rx transfer_tx persistent_keepalive
+		read -r public_key preshared_key endpoint allowed_ips latest_handshake transfer_rx transfer_tx persistent_keepalive
 		printf '%s\t\t\t"%s": {' "$delim" "$public_key"
 		delim=$'\n'
+		[[ $preshared_key == "(none)" ]] || { printf '%s\t\t\t\t"presharedKey": "%s"' "$delim" "$preshared_key"; delim=$',\n'; }
 		[[ $endpoint == "(none)" ]] || { printf '%s\t\t\t\t"endpoint": "%s"' "$delim" "$endpoint"; delim=$',\n'; }
 		[[ $latest_handshake == "0" ]] || { printf '%s\t\t\t\t"latestHandshake": %u' "$delim" $(( $latest_handshake )); delim=$',\n'; }
 		[[ $transfer_rx == "0" ]] || { printf '%s\t\t\t\t"transferRx": %u' "$delim" $(( $transfer_rx )); delim=$',\n'; }

src/completion/wg.bash-completion

@@ -21,7 +21,7 @@ _wg_completion() {
 	fi
 
 	if [[ $COMP_CWORD -eq 3 && ${COMP_WORDS[1]} == show && ${COMP_WORDS[2]} != interfaces ]]; then
-		COMPREPLY+=( $(compgen -W "public-key private-key preshared-key listen-port peers endpoints allowed-ips fwmark latest-handshakes persistent-keepalive transfer dump" -- "${COMP_WORDS[3]}") )
+		COMPREPLY+=( $(compgen -W "public-key private-key listen-port peers preshared-keys endpoints allowed-ips fwmark latest-handshakes persistent-keepalive transfer dump" -- "${COMP_WORDS[3]}") )
 		return
 	fi
 
@@ -39,7 +39,6 @@ _wg_completion() {
 		[[ ${COMP_WORDS[i]} == listen-port ]] && has_listen_port=1
 		[[ ${COMP_WORDS[i]} == fwmark ]] && has_fwmark=1
 		[[ ${COMP_WORDS[i]} == private-key ]] && has_private_key=1
-		[[ ${COMP_WORDS[i]} == preshared-key ]] && has_preshared_key=1
 		[[ ${COMP_WORDS[i]} == peer ]] && { has_peer=$i; break; }
 	done
 	if [[ $has_peer -eq 0 ]]; then
@@ -47,7 +46,6 @@ _wg_completion() {
 			[[ $has_listen_port -eq 1 ]] || words+=( listen-port )
 			[[ $has_fwmark -eq 1 ]] || words+=( fwmark )
 			[[ $has_private_key -eq 1 ]] || words+=( private-key )
-			[[ $has_preshared_key -eq 1 ]] || words+=( preshared-key )
 			words+=( peer )
 			COMPREPLY+=( $(compgen -W "${words[*]}" -- "${COMP_WORDS[COMP_CWORD]}") )
 		elif [[ ${COMP_WORDS[COMP_CWORD-1]} == *-key ]]; then
@@ -70,6 +68,7 @@ _wg_completion() {
 			has_endpoint=0
 			has_persistent_keepalive=0
 			has_allowed_ips=0
+			has_preshared_key=0
 			[[ ${COMP_WORDS[i+2]} == = ]] && ((i+=2)) || ((i++))
 			continue
 		fi
@@ -77,6 +76,7 @@ _wg_completion() {
 		[[ ${COMP_WORDS[i]} == endpoint ]] && has_endpoint=1
 		[[ ${COMP_WORDS[i]} == persistent-keepalive ]] && has_persistent_keepalive=1
 		[[ ${COMP_WORDS[i]} == allowed-ips ]] && has_allowed_ips=1
+		[[ ${COMP_WORDS[i]} == preshared-key ]] && has_preshared_key=1
 
 		[[ ${COMP_WORDS[i]} == remove ]] || ((i++))
 	done
@@ -84,6 +84,7 @@ _wg_completion() {
 	((COMP_CWORD == j)) || return
 
 	if [[ $has_remove -ne 1 ]]; then
+		[[ $has_preshared_key -eq 1 ]] || words+=( preshared-key )
 		[[ $has_endpoint -eq 1 ]] || words+=( endpoint )
 		[[ $has_allowed_ips -eq 1 ]] || words+=( allowed-ips )
 		[[ $has_persistent_keepalive -eq 1 ]] || words+=( persistent-keepalive )

src/config.c

@@ -323,10 +323,6 @@ static bool process_line(struct config_ctx *ctx, const char *line)
 			ret = parse_key(ctx->buf.dev->private_key, value);
 			if (!ret)
 				memset(ctx->buf.dev->private_key, 0, WG_KEY_LEN);
-		} else if (key_match("PresharedKey")) {
-			ret = parse_key(ctx->buf.dev->preshared_key, value);
-			if (!ret)
-				memset(ctx->buf.dev->preshared_key, 0, WG_KEY_LEN);
 		} else
 			goto error;
 	} else if (ctx->is_peer_section) {
@@ -338,7 +334,11 @@ static bool process_line(struct config_ctx *ctx, const char *line)
 			ret = parse_ipmasks(&ctx->buf, ctx->peer_offset, value);
 		else if (key_match("PersistentKeepalive"))
 			ret = parse_persistent_keepalive(&peer_from_offset(ctx->buf.dev, ctx->peer_offset)->persistent_keepalive_interval, value);
-		else
+		else if (key_match("PresharedKey")) {
+			ret = parse_key(peer_from_offset(ctx->buf.dev, ctx->peer_offset)->preshared_key, value);
+			if (!ret)
+				memset(peer_from_offset(ctx->buf.dev, ctx->peer_offset)->preshared_key, 0, WG_KEY_LEN);
+		} else
 			goto error;
 	} else
 		goto error;
@@ -408,8 +408,6 @@ bool config_read_finish(struct config_ctx *ctx)
 		fprintf(stderr, "No private key configured\n");
 		goto err;
 	}
-	if (ctx->buf.dev->flags & WGDEVICE_REPLACE_PEERS && !key_is_valid(ctx->buf.dev->preshared_key))
-		ctx->buf.dev->flags |= WGDEVICE_REMOVE_PRESHARED_KEY;
 	if (ctx->buf.dev->flags & WGDEVICE_REPLACE_PEERS && !ctx->buf.dev->fwmark)
 		ctx->buf.dev->flags |= WGDEVICE_REMOVE_FWMARK;
 
@@ -508,21 +506,6 @@ bool config_read_cmd(struct wgdevice **device, char *argv[], int argc)
 				goto error;
 			argv += 2;
 			argc -= 2;
-		} else if (!strcmp(argv[0], "preshared-key") && argc >= 2 && !buf.dev->num_peers) {
-			char *line;
-			int ret = read_line(&line, argv[1]);
-			if (ret == 0) {
-				if (!parse_key(buf.dev->preshared_key, line)) {
-					free(line);
-					goto error;
-				}
-				free(line);
-			} else if (ret == 1)
-				buf.dev->flags |= WGDEVICE_REMOVE_PRESHARED_KEY;
-			else
-				goto error;
-			argv += 2;
-			argc -= 2;
 		} else if (!strcmp(argv[0], "peer") && argc >= 2) {
 			peer_offset = buf.pos;
 			if (use_space(&buf, sizeof(struct wgpeer)) < 0) {
@@ -560,6 +543,22 @@ bool config_read_cmd(struct wgdevice **device, char *argv[], int argc)
 				goto error;
 			argv += 2;
 			argc -= 2;
+		} else if (!strcmp(argv[0], "preshared-key") && argc >= 2 && buf.dev->num_peers) {
+			char *line;
+			int ret = read_line(&line, argv[1]);
+			if (ret == 0) {
+				if (!parse_key(peer_from_offset(buf.dev, peer_offset)->preshared_key, line)) {
+					free(line);
+					goto error;
+				}
+				free(line);
+			} else if (ret == 1) {
+				free(line);
+				buf.dev->flags |= WGPEER_REMOVE_PRESHARED_KEY;
+			} else
+				goto error;
+			argv += 2;
+			argc -= 2;
 		} else {
 			fprintf(stderr, "Invalid argument: %s\n", argv[0]);
 			goto error;

src/set.c

@@ -13,7 +13,7 @@ int set_main(int argc, char *argv[])
 	int ret = 1;
 
 	if (argc < 3) {
-		fprintf(stderr, "Usage: %s %s <interface> [listen-port <port>] [fwmark <mark>] [private-key <file path>] [peer <base64 public key> [remove] [endpoint <ip>:<port>] [persistent-keepalive <interval seconds>] [allowed-ips <ip1>/<cidr1>[,<ip2>/<cidr2>]...] ]...\n", PROG_NAME, argv[0]);
+		fprintf(stderr, "Usage: %s %s <interface> [listen-port <port>] [fwmark <mark>] [private-key <file path>] [peer <base64 public key> [remove] [preshared-key <file path>] [endpoint <ip>:<port>] [persistent-keepalive <interval seconds>] [allowed-ips <ip1>/<cidr1>[,<ip2>/<cidr2>]...] ]...\n", PROG_NAME, argv[0]);
 		return 1;
 	}
 

src/show.c

@@ -201,7 +201,7 @@ static char *bytes(uint64_t b)
 static const char *COMMAND_NAME = NULL;
 static void show_usage(void)
 {
-	fprintf(stderr, "Usage: %s %s { <interface> | all | interfaces } [public-key | private-key | preshared-key | listen-port | fwmark | peers | endpoints | allowed-ips | latest-handshakes | transfer | persistent-keepalive | dump]\n", PROG_NAME, COMMAND_NAME);
+	fprintf(stderr, "Usage: %s %s { <interface> | all | interfaces } [public-key | private-key | listen-port | fwmark | peers | preshared-keys | endpoints | allowed-ips | latest-handshakes | transfer | persistent-keepalive | dump]\n", PROG_NAME, COMMAND_NAME);
 }
 
 static void pretty_print(struct wgdevice *device)
@@ -216,8 +216,6 @@ static void pretty_print(struct wgdevice *device)
 		terminal_printf("  " TERMINAL_BOLD "public key" TERMINAL_RESET ": %s\n", key(device->public_key));
 	if (memcmp(device->private_key, zero, WG_KEY_LEN))
 		terminal_printf("  " TERMINAL_BOLD "private key" TERMINAL_RESET ": %s\n", masked_key(device->private_key));
-	if (memcmp(device->preshared_key, zero, WG_KEY_LEN))
-		terminal_printf("  " TERMINAL_BOLD "preshared key" TERMINAL_RESET ": %s\n", masked_key(device->preshared_key));
 	if (device->port)
 		terminal_printf("  " TERMINAL_BOLD "listening port" TERMINAL_RESET ": %u\n", device->port);
 	if (device->fwmark)
@@ -228,6 +226,8 @@ static void pretty_print(struct wgdevice *device)
 	}
 	for_each_wgpeer(device, peer, i) {
 		terminal_printf(TERMINAL_FG_YELLOW TERMINAL_BOLD "peer" TERMINAL_RESET ": " TERMINAL_FG_YELLOW "%s" TERMINAL_RESET "\n", key(peer->public_key));
+		if (memcmp(peer->preshared_key, zero, WG_KEY_LEN))
+			terminal_printf("  " TERMINAL_BOLD "preshared key" TERMINAL_RESET ": %s\n", masked_key(peer->preshared_key));
 		if (peer->endpoint.addr.sa_family == AF_INET || peer->endpoint.addr.sa_family == AF_INET6)
 			terminal_printf("  " TERMINAL_BOLD "endpoint" TERMINAL_RESET ": %s\n", endpoint(&peer->endpoint.addr));
 		terminal_printf("  " TERMINAL_BOLD "allowed ips" TERMINAL_RESET ": ");
@@ -260,7 +260,6 @@ static void dump_print(struct wgdevice *device, bool with_interface)
 		printf("%s\t", device->interface);
 	printf("%s\t", key(device->private_key));
 	printf("%s\t", key(device->public_key));
-	printf("%s\t", key(device->preshared_key));
 	printf("%u\t", device->port);
 	if (device->fwmark)
 		printf("0x%x\n", device->fwmark);
@@ -270,6 +269,7 @@ static void dump_print(struct wgdevice *device, bool with_interface)
 		if (with_interface)
 			printf("%s\t", device->interface);
 		printf("%s\t", key(peer->public_key));
+		printf("%s\t", key(peer->preshared_key));
 		if (peer->endpoint.addr.sa_family == AF_INET || peer->endpoint.addr.sa_family == AF_INET6)
 			printf("%s\t", endpoint(&peer->endpoint.addr));
 		else
@@ -301,10 +301,6 @@ static bool ugly_print(struct wgdevice *device, const char *param, bool with_int
 		if (with_interface)
 			printf("%s\t", device->interface);
 		printf("%s\n", key(device->private_key));
-	} else if (!strcmp(param, "preshared-key")) {
-		if (with_interface)
-			printf("%s\t", device->interface);
-		printf("%s\n", key(device->preshared_key));
 	} else if (!strcmp(param, "listen-port")) {
 		if (with_interface)
 			printf("%s\t", device->interface);
@@ -358,6 +354,13 @@ static bool ugly_print(struct wgdevice *device, const char *param, bool with_int
 			else
 				printf("%s\toff\n", key(peer->public_key));
 		}
+	} else if (!strcmp(param, "preshared-keys")) {
+		for_each_wgpeer(device, peer, i) {
+			if (with_interface)
+				printf("%s\t", device->interface);
+			printf("%s\t", key(peer->public_key));
+			printf("%s\n", key(peer->preshared_key));
+		}
 	} else if (!strcmp(param, "peers")) {
 		for_each_wgpeer(device, peer, i) {
 			if (with_interface)

src/showconf.c

@@ -50,14 +50,14 @@ int showconf_main(int argc, char *argv[])
 		key_to_base64(base64, device->private_key);
 		printf("PrivateKey = %s\n", base64);
 	}
-	if (memcmp(device->preshared_key, zero, WG_KEY_LEN)) {
-		key_to_base64(base64, device->preshared_key);
-		printf("PresharedKey = %s\n", base64);
-	}
 	printf("\n");
 	for_each_wgpeer(device, peer, i) {
 		key_to_base64(base64, peer->public_key);
 		printf("[Peer]\nPublicKey = %s\n", base64);
+		if (memcmp(peer->preshared_key, zero, WG_KEY_LEN)) {
+			key_to_base64(base64, peer->preshared_key);
+			printf("PresharedKey = %s\n", base64);
+		}
 		if (peer->num_ipmasks)
 			printf("AllowedIPs = ");
 		for_each_wgipmask(peer, ipmask, j) {

src/wg.8

@@ -36,7 +36,7 @@ Sub-commands that take an INTERFACE must be passed a WireGuard interface.
 .SH COMMANDS
 
 .TP
-\fBshow\fP { \fI<interface>\fP | \fIall\fP | \fIinterfaces\fP } [\fIpublic-key\fP | \fIprivate-key\fP | \fIpreshared-key\fP | \fIlisten-port\fP | \fIfwmark\fP | \fIpeers\fP | \fIendpoints\fP | \fIallowed-ips\fP | \fIlatest-handshakes\fP | \fIpersistent-keepalive\fP | \fItransfer\fP | \fIdump\fP]
+\fBshow\fP { \fI<interface>\fP | \fIall\fP | \fIinterfaces\fP } [\fIpublic-key\fP | \fIprivate-key\fP | \fIlisten-port\fP | \fIfwmark\fP | \fIpeers\fP | \fIpreshared-keys\fP | \fIendpoints\fP | \fIallowed-ips\fP | \fIlatest-handshakes\fP | \fIpersistent-keepalive\fP | \fItransfer\fP | \fIdump\fP]
 Shows current WireGuard configuration of specified \fI<interface>\fP.
 If no \fI<interface>\fP is specified, \fI<interface>\fP defaults to \fIall\fP.
 If \fIinterfaces\fP is specified, prints a list of all WireGuard interfaces,
@@ -46,16 +46,16 @@ meant for the terminal. Otherwise, prints specified information grouped by
 newlines and tabs, meant to be used in scripts. For this script-friendly display,
 if \fIall\fP is specified, then the first field for all categories of information
 is the interface name. If \fPdump\fP is specified, then several lines are printed;
-the first contains in order separated by tab: private-key, public-key, preshared-key,
+the first contains in order separated by tab: private-key, public-key, listen-port,
-listen-port, fwmark. Subsequent lines are printed for each peer and contain in order
+fwmark. Subsequent lines are printed for each peer and contain in order separated
-separated by tab: public-key, endpoint, allowed-ips, latest-handshake, transfer-rx,
+by tab: public-key, preshared-key, endpoint, allowed-ips, latest-handshake,
-transfer-tx, persistent-keepalive.
+transfer-rx, transfer-tx, persistent-keepalive.
 .TP
 \fBshowconf\fP \fI<interface>\fP
 Shows the current configuration of \fI<interface>\fP in the format described
 by \fICONFIGURATION FILE FORMAT\fP below.
 .TP
-\fBset\fP \fI<interface>\fP [\fIlisten-port\fP \fI<port>\fP] [\fIfwmark\fP \fI<fwmark>\fP] [\fIprivate-key\fP \fI<file-path>\fP] [\fIpreshared-key\fP \fI<file-path>\fP] [\fIpeer\fP \fI<base64-public-key>\fP [\fIremove\fP] [\fIendpoint\fP \fI<ip>:<port>\fP] [\fIpersistent-keepalive\fP \fI<interval seconds>\fP] [\fIallowed-ips\fP \fI<ip1>/<cidr1>\fP[,\fI<ip2>/<cidr2>\fP]...] ]...
+\fBset\fP \fI<interface>\fP [\fIlisten-port\fP \fI<port>\fP] [\fIfwmark\fP \fI<fwmark>\fP] [\fIprivate-key\fP \fI<file-path>\fP] [\fIpeer\fP \fI<base64-public-key>\fP [\fIremove\fP] [\fIpreshared-key\fP \fI<file-path>\fP] [\fIendpoint\fP \fI<ip>:<port>\fP] [\fIpersistent-keepalive\fP \fI<interval seconds>\fP] [\fIallowed-ips\fP \fI<ip1>/<cidr1>\fP[,\fI<ip2>/<cidr2>\fP]...] ]...
 Sets configuration values for the specified \fI<interface>\fP. Multiple
 \fIpeer\fPs may be specified, and if the \fIremove\fP argument is given
 for a peer, that peer is removed, not configured. If \fIlisten-port\fP
@@ -126,11 +126,6 @@ The \fIInterface\fP section may contain the following fields:
 .IP \(bu
 PrivateKey \(em a base64 private key generated by \fIwg genkey\fP. Required.
 .IP \(bu
-PresharedKey \(em a base64 preshared key generated by \fIwg genpsk\fP. Optional,
-and may be omitted. This option adds an additional layer of symmetric-key
-cryptography to be mixed into the already existing public-key cryptography,
-for post-quantum resistance.
-.IP \(bu
 ListenPort \(em a 16-bit port for listening. Optional; if not specified, chosen
 randomly.
 .IP \(bu
@@ -143,6 +138,11 @@ PublicKey \(em a base64 public key calculated by \fIwg pubkey\fP from a
 private key, and usually transmitted out of band to the author of the
 configuration file. Required.
 .IP \(bu
+PresharedKey \(em a base64 preshared key generated by \fIwg genpsk\fP. Optional,
+and may be omitted. This option adds an additional layer of symmetric-key
+cryptography to be mixed into the already existing public-key cryptography,
+for post-quantum resistance.
+.IP \(bu
 AllowedIPs \(em a comma-separated list of ip (v4 or v6) addresses with
 CIDR masks from which this peer is allowed to send incoming traffic and
 to which outgoing traffic for this peer is directed. The catch-all