OSPF: Use message authentication interface (29239ba2) · Commits · 戴 / Bird

proto/ospf/config.Y

+14 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,20 @@ ospf_iface_finish(void)

		if ((ip->autype == OSPF_AUTH_NONE) && (ip->passwords != NULL))
		log(L_WARN "Password option without authentication option does not make sense");

		if (ip->passwords)
		{
		struct password_item *pass;
		WALK_LIST(pass, *ip->passwords)
		{
		if (pass->alg && (ip->autype != OSPF_AUTH_CRYPT))
		cf_error("Password algorithm option requires cryptographic authentication");

		/* Set default OSPF crypto algorithms */
		if (!pass->alg && (ip->autype == OSPF_AUTH_CRYPT))
		pass->alg = ospf_cfg_is_v2() ? ALG_MD5 : ALG_HMAC_SHA256;
		}
		}
		}

		static void

proto/ospf/iface.c

+19 −5

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@
		*/

		#include "ospf.h"
		#include "nest/password.h"


		const char *ospf_is_names[] = {
		@@ -51,6 +52,18 @@ ifa_tx_length(struct ospf_iface *ifa)
		return ifa->cf->tx_length ?: ifa->iface->mtu;
		}

		static inline uint
		ifa_tx_hdrlen(struct ospf_iface *ifa)
		{
		uint hlen = SIZE_OF_IP_HEADER;

		/* Relevant just for OSPFv2 */
		if (ifa->autype == OSPF_AUTH_CRYPT)
		hlen += max_mac_length(ifa->passwords);

		return hlen;
		}

		static inline uint
		ifa_bufsize(struct ospf_iface *ifa)
		{
		@@ -67,11 +80,7 @@ ifa_flood_queue_size(struct ospf_iface *ifa)
		int
		ospf_iface_assure_bufsize(struct ospf_iface *ifa, uint plen)
		{
		plen += SIZE_OF_IP_HEADER;

		/* This is relevant just for OSPFv2 */
		if (ifa->autype == OSPF_AUTH_CRYPT)
		plen += OSPF_AUTH_CRYPT_SIZE;
		plen += ifa->tx_hdrlen;

		if (plen <= ifa->sk->tbsize)
		return 0;
		@@ -574,6 +583,7 @@ ospf_iface_new(struct ospf_area oa, struct ifa addr, struct ospf_iface_patt *i
		ifa->stub = ospf_iface_stubby(ip, addr);
		ifa->ioprob = OSPF_I_OK;
		ifa->tx_length = ifa_tx_length(ifa);
		ifa->tx_hdrlen = ifa_tx_hdrlen(ifa);
		ifa->check_link = ip->check_link;
		ifa->ecmp_weight = ip->ecmp_weight;
		ifa->check_ttl = (ip->ttl_security == 1);
		@@ -684,6 +694,7 @@ ospf_iface_new_vlink(struct ospf_proto p, struct ospf_iface_patt ip)
		ifa->deadint = ip->deadint;
		ifa->inftransdelay = ip->inftransdelay;
		ifa->tx_length = ospf_is_v2(p) ? IP4_MIN_MTU : IP6_MIN_MTU;
		ifa->tx_hdrlen = ifa_tx_hdrlen(ifa);
		ifa->autype = ip->autype;
		ifa->passwords = ip->passwords;
		ifa->instance_id = ip->instance_id;
		@@ -824,6 +835,9 @@ ospf_iface_reconfigure(struct ospf_iface ifa, struct ospf_iface_patt new)
		/* Update passwords */
		ifa->passwords = new->passwords;

		/* Update header length */
		ifa->tx_hdrlen = ifa_tx_hdrlen(ifa);

		/* Remaining options are just for proper interfaces */
		if (ifa->type == OSPF_IT_VLINK)
		return 1;

proto/ospf/ospf.h

+12 −9

Original line number	Diff line number	Diff line
		@@ -180,11 +180,7 @@ struct ospf_iface_patt

		#define OSPF_RXBUF_MINSIZE 256 /* Minimal allowed size */
		u8 instance_id;
		u8 autype; /* Not really used in OSPFv3 */
		#define OSPF_AUTH_NONE 0
		#define OSPF_AUTH_SIMPLE 1
		#define OSPF_AUTH_CRYPT 2
		#define OSPF_AUTH_CRYPT_SIZE 16
		u8 autype; /* OSPF_AUTH_, not really used in OSPFv3 /
		u8 strictnbma;
		u8 check_link;
		u8 ecmp_weight;
		@@ -334,6 +330,7 @@ struct ospf_iface
		u8 marked; /* Used in OSPF reconfigure, 2 for force restart */
		u16 rxbuf; /* Buffer size */
		u16 tx_length; /* Soft TX packet length limit, usually MTU */
		u16 tx_hdrlen; /* Expected packet header length, less than tx_length */
		u8 check_link; /* Whether iface link change is used */
		u8 ecmp_weight; /* Weight used for ECMP */
		u8 link_lsa_suppression; /* Suppression of Link-LSA origination */
		@@ -424,6 +421,11 @@ struct ospf_neighbor
		#define ISM_UNLOOP 5 /* Link up */
		#define ISM_DOWN 6 /* Interface down */

		/* OSPF authentication types */
		#define OSPF_AUTH_NONE 0
		#define OSPF_AUTH_SIMPLE 1
		#define OSPF_AUTH_CRYPT 2


		/* OSPF neighbor states */
		#define NEIGHBOR_DOWN 0
		@@ -455,7 +457,6 @@ struct ospf_neighbor
		#define TRANS_WAIT 2 /* Waiting before the end of translation */



		/* Generic option flags */
		#define OPT_V6 0x01 /* OSPFv3, LSA relevant for IPv6 routing calculation */
		#define OPT_E 0x02 /* Related to AS-external LSAs */
		@@ -491,7 +492,7 @@ struct ospf_packet
		u8 autype; /* Undefined for OSPFv3 */
		};

		struct ospf_md5
		struct ospf_auth_crypto
		{
		u16 zero;
		u8 keyid;
		@@ -502,7 +503,7 @@ struct ospf_md5
		union ospf_auth
		{
		u8 password[8];
		struct ospf_md5 md5;
		struct ospf_auth_crypto c32;
		};

		/* Packet types */
		@@ -896,7 +897,6 @@ void ospf_sh_neigh_info(struct ospf_neighbor *n);

		/* packet.c */
		void ospf_pkt_fill_hdr(struct ospf_iface ifa, void buf, u8 h_type);
		uint ospf_pkt_maxsize(struct ospf_iface *ifa);
		int ospf_rx_hook(sock * sk, uint size);
		// void ospf_tx_hook(sock * sk);
		void ospf_err_hook(sock * sk, int err);
		@@ -905,6 +905,9 @@ void ospf_send_to(struct ospf_iface *ifa, ip_addr ip);
		void ospf_send_to_agt(struct ospf_iface *ifa, u8 state);
		void ospf_send_to_bdr(struct ospf_iface *ifa);

		static inline uint ospf_pkt_maxsize(struct ospf_iface *ifa)
		{ return ifa->tx_length - ifa->tx_hdrlen; }

		static inline void ospf_send_to_all(struct ospf_iface *ifa)
		{ ospf_send_to(ifa, ifa->all_routers); }

proto/ospf/packet.c

+49 −59

Original line number	Diff line number	Diff line
		@@ -32,25 +32,12 @@ ospf_pkt_fill_hdr(struct ospf_iface ifa, void buf, u8 h_type)
		pkt->autype = ifa->autype;
		}

		uint
		ospf_pkt_maxsize(struct ospf_iface *ifa)
		{
		uint headers = SIZE_OF_IP_HEADER;

		/* Relevant just for OSPFv2 */
		if (ifa->autype == OSPF_AUTH_CRYPT)
		headers += OSPF_AUTH_CRYPT_SIZE;

		return ifa->tx_length - headers;
		}

		/* We assume OSPFv2 in ospf_pkt_finalize() */
		static void
		ospf_pkt_finalize(struct ospf_iface ifa, struct ospf_packet pkt)
		ospf_pkt_finalize(struct ospf_iface ifa, struct ospf_packet pkt, uint *plen)
		{
		struct password_item *passwd = NULL;
		struct password_item *pass = NULL;
		union ospf_auth auth = (void ) (pkt + 1);
		uint plen = ntohs(pkt->length);

		pkt->checksum = 0;
		pkt->autype = ifa->autype;
		@@ -62,25 +49,25 @@ ospf_pkt_finalize(struct ospf_iface ifa, struct ospf_packet pkt)
		switch (ifa->autype)
		{
		case OSPF_AUTH_SIMPLE:
		passwd = password_find(ifa->passwords, 1);
		if (!passwd)
		pass = password_find(ifa->passwords, 1);
		if (!pass)
		{
		log(L_ERR "No suitable password found for authentication");
		return;
		}
		strncpy(auth->password, passwd->password, sizeof(auth->password));
		strncpy(auth->password, pass->password, sizeof(auth->password));

		case OSPF_AUTH_NONE:
		{
		void body = (void ) (auth + 1);
		uint blen = plen - sizeof(struct ospf_packet) - sizeof(union ospf_auth);
		uint blen = *plen - sizeof(struct ospf_packet) - sizeof(union ospf_auth);
		pkt->checksum = ipsum_calculate(pkt, sizeof(struct ospf_packet), body, blen, NULL);
		}
		break;

		case OSPF_AUTH_CRYPT:
		passwd = password_find(ifa->passwords, 0);
		if (!passwd)
		pass = password_find(ifa->passwords, 0);
		if (!pass)
		{
		log(L_ERR "No suitable password found for authentication");
		return;
		@@ -101,20 +88,25 @@ ospf_pkt_finalize(struct ospf_iface ifa, struct ospf_packet pkt)

		ifa->csn_use = now;

		auth->md5.zero = 0;
		auth->md5.keyid = passwd->id;
		auth->md5.len = OSPF_AUTH_CRYPT_SIZE;
		auth->md5.csn = htonl(ifa->csn);
		uint auth_len = mac_type_length(pass->alg);
		byte auth_tail = ((byte ) pkt + *plen);
		*plen += auth_len;

		ASSERT(*plen < ifa->sk->tbsize);

		void tail = ((void ) pkt) + plen;
		char password[OSPF_AUTH_CRYPT_SIZE];
		strncpy(password, passwd->password, sizeof(password));
		auth->c32.zero = 0;
		auth->c32.keyid = pass->id;
		auth->c32.len = auth_len;
		auth->c32.csn = htonl(ifa->csn);

		struct hash_context ctx;
		md5_init(&ctx);
		md5_update(&ctx, (char *) pkt, plen);
		md5_update(&ctx, password, OSPF_AUTH_CRYPT_SIZE);
		memcpy((byte *) tail, md5_final(&ctx), MD5_SIZE);
		/* Append key for keyed hash, append padding for HMAC (RFC 5709 3.3) */
		if (pass->alg < ALG_HMAC)
		strncpy(auth_tail, pass->password, auth_len);
		else
		memset32(auth_tail, HMAC_MAGIC, auth_len / 4);

		mac_fill(pass->alg, pass->password, pass->length,
		(byte ) pkt, plen, auth_tail);
		break;

		default:
		@@ -155,13 +147,19 @@ ospf_pkt_checkauth(struct ospf_neighbor n, struct ospf_iface ifa, struct ospf_
		return 1;

		case OSPF_AUTH_CRYPT:
		if (auth->md5.len != OSPF_AUTH_CRYPT_SIZE)
		DROP("invalid MD5 digest length", auth->md5.len);
		pass = password_find_by_id(ifa->passwords, auth->c32.keyid);
		if (!pass)
		DROP("no suitable password found", auth->c32.keyid);

		uint auth_len = mac_type_length(pass->alg);

		if (plen + OSPF_AUTH_CRYPT_SIZE > len)
		DROP("length mismatch", len);
		if (plen + auth->c32.len > len)
		DROP("packet length mismatch", len);

		u32 rcv_csn = ntohl(auth->md5.csn);
		if (auth->c32.len != auth_len)
		DROP("wrong authentication length", auth->c32.len);

		u32 rcv_csn = ntohl(auth->c32.csn);
		if (n && (rcv_csn < n->csn))
		// DROP("lower sequence number", rcv_csn);
		{
		@@ -172,22 +170,19 @@ ospf_pkt_checkauth(struct ospf_neighbor n, struct ospf_iface ifa, struct ospf_
		return 0;
		}

		pass = password_find_by_id(ifa->passwords, auth->md5.keyid);
		if (!pass)
		DROP("no suitable password found", auth->md5.keyid);

		byte tail = ((byte ) pkt) + plen;
		char received[OSPF_AUTH_CRYPT_SIZE];
		memcpy(received, tail, OSPF_AUTH_CRYPT_SIZE);
		strncpy(tail, pass->password, OSPF_AUTH_CRYPT_SIZE);
		byte auth_tail = ((byte ) pkt) + plen;
		byte *auth_data = alloca(auth_len);
		memcpy(auth_data, auth_tail, auth_len);

		struct hash_context ctx;
		md5_init(&ctx);
		md5_update(&ctx, (byte *) pkt, plen + OSPF_AUTH_CRYPT_SIZE);
		char *computed = md5_final(&ctx);
		/* Append key for keyed hash, append padding for HMAC (RFC 5709 3.3) */
		if (pass->alg < ALG_HMAC)
		strncpy(auth_tail, pass->password, auth_len);
		else
		memset32(auth_tail, HMAC_MAGIC, auth_len / 4);

		if (memcmp(received, computed, OSPF_AUTH_CRYPT_SIZE))
		DROP("wrong MD5 digest", pass->id);
		if (!mac_verify(pass->alg, pass->password, pass->length,
		(byte *) pkt, plen + auth_len, auth_data))
		DROP("wrong authentication code", pass->id);

		if (n)
		n->csn = rcv_csn;
		@@ -473,15 +468,10 @@ ospf_send_to(struct ospf_iface *ifa, ip_addr dst)
		{
		sock *sk = ifa->sk;
		struct ospf_packet pkt = (struct ospf_packet ) sk->tbuf;
		int plen = ntohs(pkt->length);
		uint plen = ntohs(pkt->length);

		if (ospf_is_v2(ifa->oa->po))
		{
		if (ifa->autype == OSPF_AUTH_CRYPT)
		plen += OSPF_AUTH_CRYPT_SIZE;

		ospf_pkt_finalize(ifa, pkt);
		}
		ospf_pkt_finalize(ifa, pkt, &plen);

		int done = sk_send_to(sk, plen, dst, 0);
		if (!done)

Admin message