/* IPsec DOI and Oakley resolution routines * Copyright (C) 1997 Angelos D. Keromytis. * Copyright (C) 1998-2002 D. Hugh Redelmeier. * Copyright (C) 2009 Andreas Steffen - Hochschule fuer Technik Rapperswil * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. See . * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. */ #include #include #include #include #include #include #include #include #include #include /* missing from on old systems */ #include #include #include #include #include #include #include #include #include #include #include "constants.h" #include "defs.h" #include "myid.h" #include "state.h" #include "x509.h" #include "ac.h" #include "crl.h" #include "ca.h" #include "certs.h" #include "smartcard.h" #include "connections.h" #include "keys.h" #include "packet.h" #include "demux.h" /* needs packet.h */ #include "adns.h" /* needs */ #include "dnskey.h" /* needs keys.h and adns.h */ #include "kernel.h" #include "log.h" #include "cookie.h" #include "server.h" #include "spdb.h" #include "timer.h" #include "ipsec_doi.h" /* needs demux.h and state.h */ #include "whack.h" #include "fetch.h" #include "pkcs7.h" #include "crypto.h" #include "vendor.h" #include "alg_info.h" #include "ike_alg.h" #include "kernel_alg.h" #include "nat_traversal.h" #include "virtual.h" /* * are we sending Pluto's Vendor ID? */ #ifdef VENDORID #define SEND_PLUTO_VID 1 #else /* !VENDORID */ #define SEND_PLUTO_VID 0 #endif /* !VENDORID */ /* * are we sending an XAUTH VID? */ #ifdef XAUTH_VID #define SEND_XAUTH_VID 1 #else /* !XAUTH_VID */ #define SEND_XAUTH_VID 0 #endif /* !XAUTH_VID */ /* * are we sending a Cisco Unity VID? */ #ifdef CISCO_QUIRKS #define SEND_CISCO_UNITY_VID 1 #else /* !CISCO_QUIRKS */ #define SEND_CISCO_UNITY_VID 0 #endif /* !CISCO_QUIRKS */ /* MAGIC: perform f, a function that returns notification_t * and return from the ENCLOSING stf_status returning function if it fails. */ #define RETURN_STF_FAILURE(f) \ { int r = (f); if (r != ISAKMP_NOTHING_WRONG) return STF_FAIL + r; } /* create output HDR as replica of input HDR */ void echo_hdr(struct msg_digest *md, bool enc, u_int8_t np) { struct isakmp_hdr r_hdr = md->hdr; /* mostly same as incoming header */ r_hdr.isa_flags &= ~ISAKMP_FLAG_COMMIT; /* we won't ever turn on this bit */ if (enc) { r_hdr.isa_flags |= ISAKMP_FLAG_ENCRYPTION; } /* some day, we may have to set r_hdr.isa_version */ r_hdr.isa_np = np; if (!out_struct(&r_hdr, &isakmp_hdr_desc, &md->reply, &md->rbody)) { impossible(); /* surely must have room and be well-formed */ } } /* Compute DH shared secret from our local secret and the peer's public value. * We make the leap that the length should be that of the group * (see quoted passage at start of ACCEPT_KE). */ static void compute_dh_shared(struct state *st, const chunk_t g) { passert(st->st_dh); st->st_dh->set_other_public_value(st->st_dh, g); st->st_dh->get_shared_secret(st->st_dh, &st->st_shared); DBG_cond_dump_chunk(DBG_CRYPT, "DH shared secret:\n", st->st_shared); } /* if we haven't already done so, compute a local DH secret (st->st_sec) and * the corresponding public value (g). This is emitted as a KE payload. */ static bool build_and_ship_KE(struct state *st, chunk_t *g, const struct dh_desc *group, pb_stream *outs, u_int8_t np) { if (st->st_dh == NULL) { st->st_dh = lib->crypto->create_dh(lib->crypto, group->algo_id); if (st->st_dh == NULL) { plog("Diffie Hellman group %N is not available", diffie_hellman_group_names, group->algo_id); return FALSE; } } st->st_dh->get_my_public_value(st->st_dh, g); DBG(DBG_CRYPT, DBG_dump_chunk("Public DH value sent:\n", *g) ) return out_generic_chunk(np, &isakmp_keyex_desc, outs, *g, "keyex value"); } /* accept_ke * * Check and accept DH public value (Gi or Gr) from peer's message. * According to RFC2409 "The Internet key exchange (IKE)" 5: * The Diffie-Hellman public value passed in a KE payload, in either * a phase 1 or phase 2 exchange, MUST be the length of the negotiated * Diffie-Hellman group enforced, if necessary, by pre-pending the * value with zeros. */ static notification_t accept_KE(chunk_t *dest, const char *val_name, const struct dh_desc *gr, pb_stream *pbs) { if (pbs_left(pbs) != gr->ke_size) { loglog(RC_LOG_SERIOUS, "KE has %u byte DH public value; %u required" , (unsigned) pbs_left(pbs), gr->ke_size); /* XXX Could send notification back */ return ISAKMP_INVALID_KEY_INFORMATION; } free(dest->ptr); *dest = chunk_create(pbs->cur, pbs_left(pbs)); *dest = chunk_clone(*dest); DBG_cond_dump_chunk(DBG_CRYPT, "DH public value received:\n", *dest); return ISAKMP_NOTHING_WRONG; } /* accept_PFS_KE * * Check and accept optional Quick Mode KE payload for PFS. * Extends ACCEPT_PFS to check whether KE is allowed or required. */ static notification_t accept_PFS_KE(struct msg_digest *md, chunk_t *dest, const char *val_name, const char *msg_name) { struct state *st = md->st; struct payload_digest *const ke_pd = md->chain[ISAKMP_NEXT_KE]; if (ke_pd == NULL) { if (st->st_pfs_group != NULL) { loglog(RC_LOG_SERIOUS, "missing KE payload in %s message", msg_name); return ISAKMP_INVALID_KEY_INFORMATION; } } else { if (st->st_pfs_group == NULL) { loglog(RC_LOG_SERIOUS, "%s message KE payload requires a GROUP_DESCRIPTION attribute in SA" , msg_name); return ISAKMP_INVALID_KEY_INFORMATION; } if (ke_pd->next != NULL) { loglog(RC_LOG_SERIOUS, "%s message contains several KE payloads; we accept at most one", msg_name); return ISAKMP_INVALID_KEY_INFORMATION; /* ??? */ } return accept_KE(dest, val_name, st->st_pfs_group, &ke_pd->pbs); } return ISAKMP_NOTHING_WRONG; } static bool build_and_ship_nonce(chunk_t *n, pb_stream *outs, u_int8_t np, const char *name) { rng_t *rng; free(n->ptr); *n = chunk_create(malloc(DEFAULT_NONCE_SIZE), DEFAULT_NONCE_SIZE); rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK); rng->get_bytes(rng, DEFAULT_NONCE_SIZE, n->ptr); rng->destroy(rng); return out_generic_chunk(np, &isakmp_nonce_desc, outs, *n, name); } static linked_list_t* collect_rw_ca_candidates(struct msg_digest *md) { linked_list_t *list = linked_list_create(); connection_t *d; d = find_host_connection(&md->iface->addr, pluto_port, (ip_address*)NULL, md->sender_port, LEMPTY); for (; d != NULL; d = d->hp_next) { /* must be a road warrior connection */ if (d->kind == CK_TEMPLATE && !(d->policy & POLICY_OPPO) && d->spd.that.ca) { enumerator_t *enumerator; identification_t *ca; bool new_entry = TRUE; enumerator = list->create_enumerator(list); while (enumerator->enumerate(enumerator, &ca)) { if (ca->equals(ca, d->spd.that.ca)) { new_entry = FALSE; break; } } enumerator->destroy(enumerator); if (new_entry) { list->insert_last(list, d->spd.that.ca->clone(d->spd.that.ca)); } } } return list; } static bool build_and_ship_CR(u_int8_t type, chunk_t ca, pb_stream *outs, u_int8_t np) { pb_stream cr_pbs; struct isakmp_cr cr_hd; cr_hd.isacr_np = np; cr_hd.isacr_type = type; /* build CR header */ if (!out_struct(&cr_hd, &isakmp_ipsec_cert_req_desc, outs, &cr_pbs)) { return FALSE; } if (ca.ptr != NULL) { /* build CR body containing the distinguished name of the CA */ if (!out_chunk(ca, &cr_pbs, "CA")) return FALSE; } close_output_pbs(&cr_pbs); return TRUE; } /* Send a notification to the peer. We could decide * whether to send the notification, based on the type and the * destination, if we care to. */ static void send_notification(struct state *sndst, u_int16_t type, struct state *encst, msgid_t msgid, u_char *icookie, u_char *rcookie, u_char *spi, size_t spisize, u_char protoid) { u_char buffer[1024]; pb_stream pbs, r_hdr_pbs; u_char *r_hashval = NULL; /* where in reply to jam hash value */ u_char *r_hash_start = NULL; /* start of what is to be hashed */ passert((sndst) && (sndst->st_connection)); plog("sending %snotification %s to %s:%u" , encst ? "encrypted " : "" , enum_name(¬ification_names, type) , ip_str(&sndst->st_connection->spd.that.host_addr) , (unsigned)sndst->st_connection->spd.that.host_port); memset(buffer, 0, sizeof(buffer)); init_pbs(&pbs, buffer, sizeof(buffer), "ISAKMP notify"); /* HDR* */ { struct isakmp_hdr hdr; hdr.isa_version = ISAKMP_MAJOR_VERSION << ISA_MAJ_SHIFT | ISAKMP_MINOR_VERSION; hdr.isa_np = encst ? ISAKMP_NEXT_HASH : ISAKMP_NEXT_N; hdr.isa_xchg = ISAKMP_XCHG_INFO; hdr.isa_msgid = msgid; hdr.isa_flags = encst ? ISAKMP_FLAG_ENCRYPTION : 0; if (icookie) { memcpy(hdr.isa_icookie, icookie, COOKIE_SIZE); } if (rcookie) { memcpy(hdr.isa_rcookie, rcookie, COOKIE_SIZE); } if (!out_struct(&hdr, &isakmp_hdr_desc, &pbs, &r_hdr_pbs)) { impossible(); } } /* HASH -- value to be filled later */ if (encst) { pb_stream hash_pbs; if (!out_generic(ISAKMP_NEXT_N, &isakmp_hash_desc, &r_hdr_pbs, &hash_pbs)) { impossible(); } r_hashval = hash_pbs.cur; /* remember where to plant value */ if (!out_zero( encst->st_oakley.hasher->hash_digest_size, &hash_pbs, "HASH")) { impossible(); } close_output_pbs(&hash_pbs); r_hash_start = r_hdr_pbs.cur; /* hash from after HASH */ } /* Notification Payload */ { pb_stream not_pbs; struct isakmp_notification isan; isan.isan_doi = ISAKMP_DOI_IPSEC; isan.isan_np = ISAKMP_NEXT_NONE; isan.isan_type = type; isan.isan_spisize = spisize; isan.isan_protoid = protoid; if (!out_struct(&isan, &isakmp_notification_desc, &r_hdr_pbs, ¬_pbs) || !out_raw(spi, spisize, ¬_pbs, "spi")) { impossible(); } close_output_pbs(¬_pbs); } /* calculate hash value and patch into Hash Payload */ if (encst) { chunk_t msgid_chunk = chunk_from_thing(msgid); chunk_t msg_chunk = { r_hash_start, r_hdr_pbs.cur-r_hash_start }; pseudo_random_function_t prf_alg; prf_t *prf; prf_alg = oakley_to_prf(encst->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, encst->st_skeyid_a); prf->get_bytes(prf, msgid_chunk, NULL); prf->get_bytes(prf, msg_chunk, r_hashval); DBG(DBG_CRYPT, DBG_log("HASH computed:"); DBG_dump("", r_hashval, prf->get_block_size(prf)); ) prf->destroy(prf); } /* Encrypt message (preserve st_iv and st_new_iv) */ if (encst) { u_char old_iv[MAX_DIGEST_LEN]; u_char new_iv[MAX_DIGEST_LEN]; u_int old_iv_len = encst->st_iv_len; u_int new_iv_len = encst->st_new_iv_len; if (old_iv_len > MAX_DIGEST_LEN || new_iv_len > MAX_DIGEST_LEN) { impossible(); } memcpy(old_iv, encst->st_iv, old_iv_len); memcpy(new_iv, encst->st_new_iv, new_iv_len); if (!IS_ISAKMP_SA_ESTABLISHED(encst->st_state)) { memcpy(encst->st_ph1_iv, encst->st_new_iv, encst->st_new_iv_len); encst->st_ph1_iv_len = encst->st_new_iv_len; } init_phase2_iv(encst, &msgid); if (!encrypt_message(&r_hdr_pbs, encst)) { impossible(); } /* restore preserved st_iv and st_new_iv */ memcpy(encst->st_iv, old_iv, old_iv_len); memcpy(encst->st_new_iv, new_iv, new_iv_len); encst->st_iv_len = old_iv_len; encst->st_new_iv_len = new_iv_len; } else { close_output_pbs(&r_hdr_pbs); } /* Send packet (preserve st_tpacket) */ { chunk_t saved_tpacket = sndst->st_tpacket; sndst->st_tpacket = chunk_create(pbs.start, pbs_offset(&pbs)); send_packet(sndst, "ISAKMP notify"); sndst->st_tpacket = saved_tpacket; } } void send_notification_from_state(struct state *st, enum state_kind state, u_int16_t type) { struct state *p1st; passert(st); if (state == STATE_UNDEFINED) state = st->st_state; if (IS_QUICK(state)) { p1st = find_phase1_state(st->st_connection, ISAKMP_SA_ESTABLISHED_STATES); if ((p1st == NULL) || (!IS_ISAKMP_SA_ESTABLISHED(p1st->st_state))) { loglog(RC_LOG_SERIOUS, "no Phase1 state for Quick mode notification"); return; } send_notification(st, type, p1st, generate_msgid(p1st), st->st_icookie, st->st_rcookie, NULL, 0, PROTO_ISAKMP); } else if (IS_ISAKMP_ENCRYPTED(state) && st->st_enc_key.ptr != NULL) { send_notification(st, type, st, generate_msgid(st), st->st_icookie, st->st_rcookie, NULL, 0, PROTO_ISAKMP); } else { /* no ISAKMP SA established - don't encrypt notification */ send_notification(st, type, NULL, 0, st->st_icookie, st->st_rcookie, NULL, 0, PROTO_ISAKMP); } } void send_notification_from_md(struct msg_digest *md, u_int16_t type) { /** * Create a dummy state to be able to use send_packet in * send_notification * * we need to set: * st_connection->that.host_addr * st_connection->that.host_port * st_connection->interface */ struct state st; connection_t cnx; passert(md); memset(&st, 0, sizeof(st)); memset(&cnx, 0, sizeof(cnx)); st.st_connection = &cnx; cnx.spd.that.host_addr = md->sender; cnx.spd.that.host_port = md->sender_port; cnx.interface = md->iface; send_notification(&st, type, NULL, 0, md->hdr.isa_icookie, md->hdr.isa_rcookie, NULL, 0, PROTO_ISAKMP); } /* Send a Delete Notification to announce deletion of ISAKMP SA or * inbound IPSEC SAs. Does nothing if no such SAs are being deleted. * Delete Notifications cannot announce deletion of outbound IPSEC/ISAKMP SAs. */ void send_delete(struct state *st) { pb_stream reply_pbs; pb_stream r_hdr_pbs; msgid_t msgid; u_char buffer[8192]; struct state *p1st; ip_said said[EM_MAXRELSPIS]; ip_said *ns = said; u_char *r_hashval, /* where in reply to jam hash value */ *r_hash_start; /* start of what is to be hashed */ bool isakmp_sa = FALSE; if (IS_IPSEC_SA_ESTABLISHED(st->st_state)) { p1st = find_phase1_state(st->st_connection, ISAKMP_SA_ESTABLISHED_STATES); if (p1st == NULL) { DBG(DBG_CONTROL, DBG_log("no Phase 1 state for Delete")); return; } if (st->st_ah.present) { ns->spi = st->st_ah.our_spi; ns->dst = st->st_connection->spd.this.host_addr; ns->proto = PROTO_IPSEC_AH; ns++; } if (st->st_esp.present) { ns->spi = st->st_esp.our_spi; ns->dst = st->st_connection->spd.this.host_addr; ns->proto = PROTO_IPSEC_ESP; ns++; } passert(ns != said); /* there must be some SAs to delete */ } else if (IS_ISAKMP_SA_ESTABLISHED(st->st_state)) { p1st = st; isakmp_sa = TRUE; } else { return; /* nothing to do */ } msgid = generate_msgid(p1st); zero(buffer); init_pbs(&reply_pbs, buffer, sizeof(buffer), "delete msg"); /* HDR* */ { struct isakmp_hdr hdr; hdr.isa_version = ISAKMP_MAJOR_VERSION << ISA_MAJ_SHIFT | ISAKMP_MINOR_VERSION; hdr.isa_np = ISAKMP_NEXT_HASH; hdr.isa_xchg = ISAKMP_XCHG_INFO; hdr.isa_msgid = msgid; hdr.isa_flags = ISAKMP_FLAG_ENCRYPTION; memcpy(hdr.isa_icookie, p1st->st_icookie, COOKIE_SIZE); memcpy(hdr.isa_rcookie, p1st->st_rcookie, COOKIE_SIZE); if (!out_struct(&hdr, &isakmp_hdr_desc, &reply_pbs, &r_hdr_pbs)) impossible(); } /* HASH -- value to be filled later */ { pb_stream hash_pbs; if (!out_generic(ISAKMP_NEXT_D, &isakmp_hash_desc, &r_hdr_pbs, &hash_pbs)) { impossible(); } r_hashval = hash_pbs.cur; /* remember where to plant value */ if (!out_zero(p1st->st_oakley.hasher->hash_digest_size, &hash_pbs, "HASH(1)")) { impossible(); } close_output_pbs(&hash_pbs); r_hash_start = r_hdr_pbs.cur; /* hash from after HASH(1) */ } /* Delete Payloads */ if (isakmp_sa) { pb_stream del_pbs; struct isakmp_delete isad; u_char isakmp_spi[2*COOKIE_SIZE]; isad.isad_doi = ISAKMP_DOI_IPSEC; isad.isad_np = ISAKMP_NEXT_NONE; isad.isad_spisize = (2 * COOKIE_SIZE); isad.isad_protoid = PROTO_ISAKMP; isad.isad_nospi = 1; memcpy(isakmp_spi, st->st_icookie, COOKIE_SIZE); memcpy(isakmp_spi+COOKIE_SIZE, st->st_rcookie, COOKIE_SIZE); if (!out_struct(&isad, &isakmp_delete_desc, &r_hdr_pbs, &del_pbs) || !out_raw(&isakmp_spi, (2*COOKIE_SIZE), &del_pbs, "delete payload")) { impossible(); } close_output_pbs(&del_pbs); } else { while (ns != said) { pb_stream del_pbs; struct isakmp_delete isad; ns--; isad.isad_doi = ISAKMP_DOI_IPSEC; isad.isad_np = ns == said? ISAKMP_NEXT_NONE : ISAKMP_NEXT_D; isad.isad_spisize = sizeof(ipsec_spi_t); isad.isad_protoid = ns->proto; isad.isad_nospi = 1; if (!out_struct(&isad, &isakmp_delete_desc, &r_hdr_pbs, &del_pbs) || !out_raw(&ns->spi, sizeof(ipsec_spi_t), &del_pbs, "delete payload")) { impossible(); } close_output_pbs(&del_pbs); } } /* calculate hash value and patch into Hash Payload */ { chunk_t msgid_chunk = chunk_from_thing(msgid); chunk_t msg_chunk = { r_hash_start, r_hdr_pbs.cur-r_hash_start }; pseudo_random_function_t prf_alg; prf_t *prf; prf_alg = oakley_to_prf(p1st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, p1st->st_skeyid_a); prf->get_bytes(prf, msgid_chunk, NULL); prf->get_bytes(prf, msg_chunk, r_hashval); DBG(DBG_CRYPT, DBG_log("HASH(1) computed:"); DBG_dump("", r_hashval, prf->get_block_size(prf)); ) prf->destroy(prf); } /* Do a dance to avoid needing a new state object. * We use the Phase 1 State. This is the one with right * IV, for one thing. * The tricky bits are: * - we need to preserve (save/restore) st_iv (but not st_iv_new) * - we need to preserve (save/restore) st_tpacket. */ { u_char old_iv[MAX_DIGEST_LEN]; chunk_t saved_tpacket = p1st->st_tpacket; memcpy(old_iv, p1st->st_iv, p1st->st_iv_len); init_phase2_iv(p1st, &msgid); if (!encrypt_message(&r_hdr_pbs, p1st)) { impossible(); } p1st->st_tpacket = chunk_create(reply_pbs.start, pbs_offset(&reply_pbs)); send_packet(p1st, "delete notify"); p1st->st_tpacket = saved_tpacket; /* get back old IV for this state */ memcpy(p1st->st_iv, old_iv, p1st->st_iv_len); } } void accept_delete(struct state *st, struct msg_digest *md, struct payload_digest *p) { struct isakmp_delete *d = &(p->payload.delete); size_t sizespi; int i; if (!md->encrypted) { loglog(RC_LOG_SERIOUS, "ignoring Delete SA payload: not encrypted"); return; } if (!IS_ISAKMP_SA_ESTABLISHED(st->st_state)) { /* can't happen (if msg is encrypt), but just to be sure */ loglog(RC_LOG_SERIOUS, "ignoring Delete SA payload: " "ISAKMP SA not established"); return; } if (d->isad_nospi == 0) { loglog(RC_LOG_SERIOUS, "ignoring Delete SA payload: no SPI"); return; } switch (d->isad_protoid) { case PROTO_ISAKMP: sizespi = 2 * COOKIE_SIZE; break; case PROTO_IPSEC_AH: case PROTO_IPSEC_ESP: sizespi = sizeof(ipsec_spi_t); break; case PROTO_IPCOMP: /* nothing interesting to delete */ return; default: loglog(RC_LOG_SERIOUS , "ignoring Delete SA payload: unknown Protocol ID (%s)" , enum_show(&protocol_names, d->isad_protoid)); return; } if (d->isad_spisize != sizespi) { loglog(RC_LOG_SERIOUS , "ignoring Delete SA payload: bad SPI size (%d) for %s" , d->isad_spisize, enum_show(&protocol_names, d->isad_protoid)); return; } if (pbs_left(&p->pbs) != d->isad_nospi * sizespi) { loglog(RC_LOG_SERIOUS , "ignoring Delete SA payload: invalid payload size"); return; } for (i = 0; i < d->isad_nospi; i++) { u_char *spi = p->pbs.cur + (i * sizespi); if (d->isad_protoid == PROTO_ISAKMP) { /** * ISAKMP */ struct state *dst = find_state(spi /*iCookie*/ , spi+COOKIE_SIZE /*rCookie*/ , &st->st_connection->spd.that.host_addr , MAINMODE_MSGID); if (dst == NULL) { loglog(RC_LOG_SERIOUS, "ignoring Delete SA payload: " "ISAKMP SA not found (maybe expired)"); } else if (!same_peer_ids(st->st_connection, dst->st_connection, NULL)) { /* we've not authenticated the relevant identities */ loglog(RC_LOG_SERIOUS, "ignoring Delete SA payload: " "ISAKMP SA used to convey Delete has different IDs from ISAKMP SA it deletes"); } else { connection_t *oldc; oldc = cur_connection; set_cur_connection(dst->st_connection); if (nat_traversal_enabled) { nat_traversal_change_port_lookup(md, dst); } loglog(RC_LOG_SERIOUS, "received Delete SA payload: " "deleting ISAKMP State #%lu", dst->st_serialno); delete_state(dst); set_cur_connection(oldc); } } else { /** * IPSEC (ESP/AH) */ bool bogus; struct state *dst = find_phase2_state_to_delete(st , d->isad_protoid , *(ipsec_spi_t *)spi /* network order */ , &bogus); if (dst == NULL) { loglog(RC_LOG_SERIOUS , "ignoring Delete SA payload: %s SA(0x%08lx) not found (%s)" , enum_show(&protocol_names, d->isad_protoid) , (unsigned long)ntohl((unsigned long)*(ipsec_spi_t *)spi) , bogus ? "our SPI - bogus implementation" : "maybe expired"); } else { connection_t *rc = dst->st_connection; connection_t *oldc; oldc = cur_connection; set_cur_connection(rc); if (nat_traversal_enabled) { nat_traversal_change_port_lookup(md, dst); } if (rc->newest_ipsec_sa == dst->st_serialno && (rc->policy & POLICY_UP)) { /* Last IPSec SA for a permanent connection that we * have initiated. Replace it in a few seconds. * * Useful if the other peer is rebooting. */ #define DELETE_SA_DELAY EVENT_RETRANSMIT_DELAY_0 if (dst->st_event != NULL && dst->st_event->ev_type == EVENT_SA_REPLACE && dst->st_event->ev_time <= DELETE_SA_DELAY + now()) { /* Patch from Angus Lees to ignore retransmited * Delete SA. */ loglog(RC_LOG_SERIOUS, "received Delete SA payload: " "already replacing IPSEC State #%lu in %d seconds" , dst->st_serialno, (int)(dst->st_event->ev_time - now())); } else { loglog(RC_LOG_SERIOUS, "received Delete SA payload: " "replace IPSEC State #%lu in %d seconds" , dst->st_serialno, DELETE_SA_DELAY); dst->st_margin = DELETE_SA_DELAY; delete_event(dst); event_schedule(EVENT_SA_REPLACE, DELETE_SA_DELAY, dst); } } else { loglog(RC_LOG_SERIOUS, "received Delete SA(0x%08lx) payload: " "deleting IPSEC State #%lu" , (unsigned long)ntohl((unsigned long)*(ipsec_spi_t *)spi) , dst->st_serialno); delete_state(dst); } /* reset connection */ set_cur_connection(oldc); } } } } /* The whole message must be a multiple of 4 octets. * I'm not sure where this is spelled out, but look at * rfc2408 3.6 Transform Payload. * Note: it talks about 4 BYTE boundaries! */ void close_message(pb_stream *pbs) { size_t padding = pad_up(pbs_offset(pbs), 4); if (padding != 0) { (void) out_zero(padding, pbs, "message padding"); } close_output_pbs(pbs); } /* Initiate an Oakley Main Mode exchange. * --> HDR;SA * Note: this is not called from demux.c */ static stf_status main_outI1(int whack_sock, connection_t *c, struct state *predecessor , lset_t policy, unsigned long try) { struct state *st = new_state(); pb_stream reply; /* not actually a reply, but you know what I mean */ pb_stream rbody; int vids_to_send = 0; /* set up new state */ st->st_connection = c; set_cur_state(st); /* we must reset before exit */ st->st_policy = policy & ~POLICY_IPSEC_MASK; st->st_whack_sock = whack_sock; st->st_try = try; st->st_state = STATE_MAIN_I1; /* determine how many Vendor ID payloads we will be sending */ if (SEND_PLUTO_VID) { vids_to_send++; } if (SEND_CISCO_UNITY_VID) { vids_to_send++; } if (c->spd.this.cert && c->spd.this.cert->cert->get_type(c->spd.this.cert->cert) == CERT_GPG) { vids_to_send++; } if (SEND_XAUTH_VID) { vids_to_send++; } /* always send DPD Vendor ID */ vids_to_send++; if (nat_traversal_enabled) { vids_to_send++; } get_cookie(TRUE, st->st_icookie, COOKIE_SIZE, &c->spd.that.host_addr); insert_state(st); /* needs cookies, connection, and msgid (0) */ if (HAS_IPSEC_POLICY(policy)) { add_pending(dup_any(whack_sock), st, c, policy, 1 , predecessor == NULL? SOS_NOBODY : predecessor->st_serialno); } if (predecessor == NULL) { plog("initiating Main Mode"); } else { plog("initiating Main Mode to replace #%lu", predecessor->st_serialno); } /* set up reply */ init_pbs(&reply, reply_buffer, sizeof(reply_buffer), "reply packet"); /* HDR out */ { struct isakmp_hdr hdr; zero(&hdr); /* default to 0 */ hdr.isa_version = ISAKMP_MAJOR_VERSION << ISA_MAJ_SHIFT | ISAKMP_MINOR_VERSION; hdr.isa_np = ISAKMP_NEXT_SA; hdr.isa_xchg = ISAKMP_XCHG_IDPROT; memcpy(hdr.isa_icookie, st->st_icookie, COOKIE_SIZE); /* R-cookie, flags and MessageID are left zero */ if (!out_struct(&hdr, &isakmp_hdr_desc, &reply, &rbody)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* SA out */ { u_char *sa_start = rbody.cur; if (!out_sa(&rbody, &oakley_sadb, st, TRUE , vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE)) { reset_cur_state(); return STF_INTERNAL_ERROR; } /* save initiator SA for later HASH */ passert(st->st_p1isa.ptr == NULL); /* no leak! (MUST be first time) */ st->st_p1isa = chunk_create(sa_start, rbody.cur - sa_start); st->st_p1isa = chunk_clone(st->st_p1isa); } /* if enabled send Pluto Vendor ID */ if (SEND_PLUTO_VID) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &rbody, VID_STRONGSWAN)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* if enabled send Cisco Unity Vendor ID */ if (SEND_CISCO_UNITY_VID) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &rbody, VID_CISCO_UNITY)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* if we have an OpenPGP certificate we assume an * OpenPGP peer and have to send the Vendor ID */ if (c->spd.this.cert && c->spd.this.cert->cert->get_type(c->spd.this.cert->cert) == CERT_GPG) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &rbody, VID_OPENPGP)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* Announce our ability to do eXtended AUTHentication to the peer */ if (SEND_XAUTH_VID) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &rbody, VID_MISC_XAUTH)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* Announce our ability to do Dead Peer Detection to the peer */ { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &rbody, VID_MISC_DPD)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } if (nat_traversal_enabled) { /* Add supported NAT-Traversal VID */ if (!nat_traversal_add_vid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &rbody)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } close_message(&rbody); close_output_pbs(&reply); st->st_tpacket = chunk_create(reply.start, pbs_offset(&reply)); st->st_tpacket = chunk_clone(st->st_tpacket); /* Transmit */ send_packet(st, "main_outI1"); /* Set up a retransmission event, half a minute henceforth */ delete_event(st); event_schedule(EVENT_RETRANSMIT, EVENT_RETRANSMIT_DELAY_0, st); if (predecessor != NULL) { update_pending(predecessor, st); whack_log(RC_NEW_STATE + STATE_MAIN_I1 , "%s: initiate, replacing #%lu" , enum_name(&state_names, st->st_state) , predecessor->st_serialno); } else { whack_log(RC_NEW_STATE + STATE_MAIN_I1 , "%s: initiate", enum_name(&state_names, st->st_state)); } reset_cur_state(); return STF_OK; } void ipsecdoi_initiate(int whack_sock, connection_t *c, lset_t policy, unsigned long try, so_serial_t replacing) { /* If there's already an ISAKMP SA established, use that and * go directly to Quick Mode. We are even willing to use one * that is still being negotiated, but only if we are the Initiator * (thus we can be sure that the IDs are not going to change; * other issues around intent might matter). * Note: there is no way to initiate with a Road Warrior. */ struct state *st = find_phase1_state(c , ISAKMP_SA_ESTABLISHED_STATES | PHASE1_INITIATOR_STATES); if (st == NULL) { (void) main_outI1(whack_sock, c, NULL, policy, try); } else if (HAS_IPSEC_POLICY(policy)) { if (!IS_ISAKMP_SA_ESTABLISHED(st->st_state)) { /* leave our Phase 2 negotiation pending */ add_pending(whack_sock, st, c, policy, try, replacing); } else { /* ??? we assume that peer_nexthop_sin isn't important: * we already have it from when we negotiated the ISAKMP SA! * It isn't clear what to do with the error return. */ (void) quick_outI1(whack_sock, st, c, policy, try, replacing); } } else { close_any(whack_sock); } } /* Replace SA with a fresh one that is similar * * Shares some logic with ipsecdoi_initiate, but not the same! * - we must not reuse the ISAKMP SA if we are trying to replace it! * - if trying to replace IPSEC SA, use ipsecdoi_initiate to build * ISAKMP SA if needed. * - duplicate whack fd, if live. * Does not delete the old state -- someone else will do that. */ void ipsecdoi_replace(struct state *st, unsigned long try) { int whack_sock = dup_any(st->st_whack_sock); lset_t policy = st->st_policy; if (IS_PHASE1(st->st_state)) { passert(!HAS_IPSEC_POLICY(policy)); (void) main_outI1(whack_sock, st->st_connection, st, policy, try); } else { /* Add features of actual old state to policy. This ensures * that rekeying doesn't downgrade security. I admit that * this doesn't capture everything. */ if (st->st_pfs_group != NULL) policy |= POLICY_PFS; if (st->st_ah.present) { policy |= POLICY_AUTHENTICATE; if (st->st_ah.attrs.encapsulation == ENCAPSULATION_MODE_TUNNEL) policy |= POLICY_TUNNEL; } if (st->st_esp.present && st->st_esp.attrs.transid != ESP_NULL) { policy |= POLICY_ENCRYPT; if (st->st_esp.attrs.encapsulation == ENCAPSULATION_MODE_TUNNEL) policy |= POLICY_TUNNEL; } if (st->st_ipcomp.present) { policy |= POLICY_COMPRESS; if (st->st_ipcomp.attrs.encapsulation == ENCAPSULATION_MODE_TUNNEL) policy |= POLICY_TUNNEL; } passert(HAS_IPSEC_POLICY(policy)); ipsecdoi_initiate(whack_sock, st->st_connection, policy, try , st->st_serialno); } } /* SKEYID for preshared keys. * See draft-ietf-ipsec-ike-01.txt 4.1 */ static bool skeyid_preshared(struct state *st) { const chunk_t *pss = get_preshared_secret(st->st_connection); if (pss == NULL) { loglog(RC_LOG_SERIOUS, "preshared secret disappeared!"); return FALSE; } else { pseudo_random_function_t prf_alg; prf_t *prf; prf_alg = oakley_to_prf(st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); if (prf == NULL) { loglog(RC_LOG_SERIOUS, "%N not available to compute skeyid", pseudo_random_function_names, prf_alg); return FALSE; } free(st->st_skeyid.ptr); prf->set_key(prf, *pss); prf->allocate_bytes(prf, st->st_ni, NULL); prf->allocate_bytes(prf, st->st_nr, &st->st_skeyid); prf->destroy(prf); return TRUE; } } static bool skeyid_digisig(struct state *st) { chunk_t nir; pseudo_random_function_t prf_alg; prf_t *prf; prf_alg = oakley_to_prf(st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); if (prf == NULL) { loglog(RC_LOG_SERIOUS, "%N not available to compute skeyid", pseudo_random_function_names, prf_alg); return FALSE; } free(st->st_skeyid.ptr); nir = chunk_cat("cc", st->st_ni, st->st_nr); prf->set_key(prf, nir); prf->allocate_bytes(prf, st->st_shared, &st->st_skeyid); prf->destroy(prf); free(nir.ptr); return TRUE; } /* Generate the SKEYID_* and new IV * See draft-ietf-ipsec-ike-01.txt 4.1 */ static bool generate_skeyids_iv(struct state *st) { /* Generate the SKEYID */ switch (st->st_oakley.auth) { case OAKLEY_PRESHARED_KEY: case XAUTHInitPreShared: case XAUTHRespPreShared: if (!skeyid_preshared(st)) { return FALSE; } break; case OAKLEY_RSA_SIG: case OAKLEY_ECDSA_256: case OAKLEY_ECDSA_384: case OAKLEY_ECDSA_521: case XAUTHInitRSA: case XAUTHRespRSA: if (!skeyid_digisig(st)) { return FALSE; } break; case OAKLEY_DSS_SIG: /* XXX */ case OAKLEY_RSA_ENC: case OAKLEY_RSA_ENC_REV: case OAKLEY_ELGAMAL_ENC: case OAKLEY_ELGAMAL_ENC_REV: /* XXX */ default: bad_case(st->st_oakley.auth); } /* generate SKEYID_* from SKEYID */ { chunk_t seed_skeyid_d = chunk_from_chars(0x00); chunk_t seed_skeyid_a = chunk_from_chars(0x01); chunk_t seed_skeyid_e = chunk_from_chars(0x02); chunk_t icookie = { st->st_icookie, COOKIE_SIZE }; chunk_t rcookie = { st->st_rcookie, COOKIE_SIZE }; pseudo_random_function_t prf_alg; prf_t *prf; prf_alg = oakley_to_prf(st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, st->st_skeyid); /* SKEYID_D */ free(st->st_skeyid_d.ptr); prf->allocate_bytes(prf, st->st_shared, NULL); prf->allocate_bytes(prf, icookie, NULL); prf->allocate_bytes(prf, rcookie, NULL); prf->allocate_bytes(prf, seed_skeyid_d, &st->st_skeyid_d); /* SKEYID_A */ free(st->st_skeyid_a.ptr); prf->allocate_bytes(prf, st->st_skeyid_d, NULL); prf->allocate_bytes(prf, st->st_shared, NULL); prf->allocate_bytes(prf, icookie, NULL); prf->allocate_bytes(prf, rcookie, NULL); prf->allocate_bytes(prf, seed_skeyid_a, &st->st_skeyid_a); /* SKEYID_E */ free(st->st_skeyid_e.ptr); prf->allocate_bytes(prf, st->st_skeyid_a, NULL); prf->allocate_bytes(prf, st->st_shared, NULL); prf->allocate_bytes(prf, icookie, NULL); prf->allocate_bytes(prf, rcookie, NULL); prf->allocate_bytes(prf, seed_skeyid_e, &st->st_skeyid_e); prf->destroy(prf); } /* generate IV */ { hash_algorithm_t hash_alg; hasher_t *hasher; hash_alg = oakley_to_hash_algorithm(st->st_oakley.hash); hasher = lib->crypto->create_hasher(lib->crypto, hash_alg); st->st_new_iv_len = hasher->get_hash_size(hasher); passert(st->st_new_iv_len <= sizeof(st->st_new_iv)); DBG(DBG_CRYPT, DBG_dump_chunk("DH_i:", st->st_gi); DBG_dump_chunk("DH_r:", st->st_gr); ); hasher->get_hash(hasher, st->st_gi, NULL); hasher->get_hash(hasher, st->st_gr, st->st_new_iv); hasher->destroy(hasher); } /* Oakley Keying Material * Derived from Skeyid_e: if it is not big enough, generate more * using the PRF. * See RFC 2409 "IKE" Appendix B */ { size_t keysize = st->st_oakley.enckeylen/BITS_PER_BYTE; /* free any existing key */ free(st->st_enc_key.ptr); if (keysize > st->st_skeyid_e.len) { u_char keytemp[MAX_OAKLEY_KEY_LEN + MAX_DIGEST_LEN]; chunk_t seed = chunk_from_chars(0x00); size_t prf_block_size, i; pseudo_random_function_t prf_alg; prf_t *prf; prf_alg = oakley_to_prf(st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, st->st_skeyid_e); prf_block_size = prf->get_block_size(prf); for (i = 0;;) { prf->get_bytes(prf, seed, &keytemp[i]); i += prf_block_size; if (i >= keysize) { break; } seed = chunk_create(&keytemp[i-prf_block_size], prf_block_size); } prf->destroy(prf); st->st_enc_key = chunk_create(keytemp, keysize); } else { st->st_enc_key = chunk_create(st->st_skeyid_e.ptr, keysize); } st->st_enc_key = chunk_clone(st->st_enc_key); } DBG(DBG_CRYPT, DBG_dump_chunk("Skeyid: ", st->st_skeyid); DBG_dump_chunk("Skeyid_d:", st->st_skeyid_d); DBG_dump_chunk("Skeyid_a:", st->st_skeyid_a); DBG_dump_chunk("Skeyid_e:", st->st_skeyid_e); DBG_dump_chunk("enc key:", st->st_enc_key); DBG_dump("IV:", st->st_new_iv, st->st_new_iv_len)); return TRUE; } /* Generate HASH_I or HASH_R for ISAKMP Phase I. * This will *not* generate other hash payloads (eg. Phase II or Quick Mode, * New Group Mode, or ISAKMP Informational Exchanges). * If the hashi argument is TRUE, generate HASH_I; if FALSE generate HASH_R. * If hashus argument is TRUE, we're generating a hash for our end. * See RFC2409 IKE 5. */ static void main_mode_hash(struct state *st, chunk_t *hash, bool hashi, const pb_stream *idpl) { chunk_t icookie = { st->st_icookie, COOKIE_SIZE }; chunk_t rcookie = { st->st_rcookie, COOKIE_SIZE }; chunk_t sa_body = { st->st_p1isa.ptr + sizeof(struct isakmp_generic), st->st_p1isa.len - sizeof(struct isakmp_generic) }; chunk_t id_body = { idpl->start + sizeof(struct isakmp_generic), pbs_offset(idpl) - sizeof(struct isakmp_generic) }; pseudo_random_function_t prf_alg; prf_t *prf; switch (st->st_oakley.auth) { case OAKLEY_ECDSA_256: prf_alg = PRF_HMAC_SHA2_256; break; case OAKLEY_ECDSA_384: prf_alg = PRF_HMAC_SHA2_384; break; case OAKLEY_ECDSA_521: prf_alg = PRF_HMAC_SHA2_512; break; default: prf_alg = oakley_to_prf(st->st_oakley.hash); } prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, st->st_skeyid); if (hashi) { prf->get_bytes(prf, st->st_gi, NULL); prf->get_bytes(prf, st->st_gr, NULL); prf->get_bytes(prf, icookie, NULL); prf->get_bytes(prf, rcookie, NULL); } else { prf->get_bytes(prf, st->st_gr, NULL); prf->get_bytes(prf, st->st_gi, NULL); prf->get_bytes(prf, rcookie, NULL); prf->get_bytes(prf, icookie, NULL); } DBG(DBG_CRYPT, DBG_log("hashing %u bytes of SA", sa_body.len) ) prf->get_bytes(prf, sa_body, NULL); /* Hash identification payload, without generic payload header. * We used to reconstruct ID Payload for this purpose, but now * we use the bytes as they appear on the wire to avoid * "spelling problems". */ prf->get_bytes(prf, id_body, hash->ptr); hash->len = prf->get_block_size(prf); prf->destroy(prf); } /* Create a public key signature of a hash. * Poorly specified in draft-ietf-ipsec-ike-01.txt 6.1.1.2. * Use PKCS#1 version 1.5 encryption of hash (called * RSAES-PKCS1-V1_5) in PKCS#2. */ static size_t sign_hash(signature_scheme_t scheme, connection_t *c, u_char sig_val[RSA_MAX_OCTETS], chunk_t hash) { size_t sz = 0; smartcard_t *sc = c->spd.this.sc; if (sc == NULL) /* no smartcard */ { chunk_t sig; private_key_t *private = get_private_key(c); if (private == NULL) { return 0; /* failure: no key to use */ } if (!private->sign(private, scheme, hash, &sig)) { return 0; } memcpy(sig_val, sig.ptr, sig.len); sz = sig.len; free(sig.ptr); } else if (sc->valid) /* if valid pin then sign hash on the smartcard */ { lock_certs_and_keys("sign_hash"); if (!scx_establish_context(sc) || !scx_login(sc)) { scx_release_context(sc); unlock_certs_and_keys("sign_hash"); return 0; } sz = scx_get_keylength(sc); if (sz == 0) { plog("failed to get keylength from smartcard"); scx_release_context(sc); unlock_certs_and_keys("sign_hash"); return 0; } DBG(DBG_CONTROL | DBG_CRYPT, DBG_log("signing hash with private key from smartcard (slot: %d, id: %s)" , (int)sc->slot, sc->id) ) sz = scx_sign_hash(sc, hash.ptr, hash.len, sig_val, sz) ? sz : 0; if (!pkcs11_keep_state) { scx_release_context(sc); } unlock_certs_and_keys("sign_hash"); } return sz; } /* Check signature against all public keys we can find. * If we need keys from DNS KEY records, and they haven't been fetched, * return STF_SUSPEND to ask for asynch DNS lookup. * * Note: parameter keys_from_dns contains results of DNS lookup for key * or is NULL indicating lookup not yet tried. * * take_a_crack is a helper function. Mostly forensic. * If only we had coroutines. */ struct tac_state { struct state *st; chunk_t hash; chunk_t sig; int tried_cnt; /* number of keys tried */ }; static bool take_a_crack(struct tac_state *s, pubkey_t *kr) { public_key_t *pub_key = kr->public_key; chunk_t keyid = chunk_empty; signature_scheme_t scheme; s->tried_cnt++; scheme = oakley_to_signature_scheme(s->st->st_oakley.auth); pub_key->get_fingerprint(pub_key, KEY_ID_PUBKEY_INFO_SHA1, &keyid); if (pub_key->verify(pub_key, scheme, s->hash, s->sig)) { DBG(DBG_CRYPT | DBG_CONTROL, DBG_log("%s check passed with keyid %#B", enum_show(&oakley_auth_names, s->st->st_oakley.auth), &keyid) ) unreference_key(&s->st->st_peer_pubkey); s->st->st_peer_pubkey = reference_key(kr); return TRUE; } else { DBG(DBG_CRYPT, DBG_log("%s check failed with keyid %#B", enum_show(&oakley_auth_names, s->st->st_oakley.auth), &keyid) ) return FALSE; } } static stf_status check_signature(key_type_t key_type, identification_t* peer, struct state *st, chunk_t hash, const pb_stream *sig_pbs, #ifdef USE_KEYRR const pubkey_list_t *keys_from_dns, #endif /* USE_KEYRR */ const struct gw_info *gateways_from_dns) { const connection_t *c = st->st_connection; struct tac_state s; s.st = st; s.hash = hash; s.sig = chunk_create(sig_pbs->cur, pbs_left(sig_pbs)); s.tried_cnt = 0; /* try all gateway records hung off c */ if (c->policy & POLICY_OPPO) { struct gw_info *gw; for (gw = c->gw_info; gw != NULL; gw = gw->next) { /* only consider entries that have a key and are for our peer */ if (gw->gw_key_present && gw->gw_id->equals(gw->gw_id, c->spd.that.id) && take_a_crack(&s, gw->key)) { return STF_OK; } } } /* try all appropriate Public keys */ { pubkey_list_t *p, **pp; pp = &pubkeys; for (p = pubkeys; p != NULL; p = *pp) { pubkey_t *key = p->key; key_type_t type = key->public_key->get_type(key->public_key); if (type == key_type && peer->equals(peer, key->id)) { time_t now = time(NULL); /* check if found public key has expired */ if (key->until_time != UNDEFINED_TIME && key->until_time < now) { loglog(RC_LOG_SERIOUS, "cached public key has expired and has been deleted"); *pp = free_public_keyentry(p); continue; /* continue with next public key */ } if (take_a_crack(&s, key)) { return STF_OK; } } pp = &p->next; } } /* if no key was found and that side of connection is * key_from_DNS_on_demand then go search DNS for keys for peer. */ if (s.tried_cnt == 0 && c->spd.that.key_from_DNS_on_demand) { if (gateways_from_dns != NULL) { /* TXT keys */ const struct gw_info *gwp; for (gwp = gateways_from_dns; gwp != NULL; gwp = gwp->next) { if (gwp->gw_key_present && take_a_crack(&s, gwp->key)) { return STF_OK; } } } #ifdef USE_KEYRR else if (keys_from_dns != NULL) { /* KEY keys */ const pubkey_list_t *kr; for (kr = keys_from_dns; kr != NULL; kr = kr->next) { if (kr->key->alg == PUBKEY_ALG_RSA && take_a_crack(&s, kr->key)) { return STF_OK; } } } #endif /* USE_KEYRR */ else { /* nothing yet: ask for asynch DNS lookup */ return STF_SUSPEND; } } /* no acceptable key was found: diagnose */ { if (s.tried_cnt == 0) { loglog(RC_LOG_SERIOUS, "no public key known for '%Y'", peer); } else if (s.tried_cnt == 1) { loglog(RC_LOG_SERIOUS, "signature check for '%Y' failed: " " wrong key?; tried %d", peer, s.tried_cnt); DBG(DBG_CONTROL, DBG_log("public key for '%Y' failed: " "decrypted SIG payload into a malformed ECB", peer) ) } else { loglog(RC_LOG_SERIOUS, "signature check for '%Y' failed: " "tried %d keys but none worked.", peer, s.tried_cnt); DBG(DBG_CONTROL, DBG_log("all %d public keys for '%Y' failed: " "best decrypted SIG payload into a malformed ECB", s.tried_cnt, peer) ) } return STF_FAIL + ISAKMP_INVALID_KEY_INFORMATION; } } static notification_t accept_nonce(struct msg_digest *md, chunk_t *dest, const char *name) { pb_stream *nonce_pbs = &md->chain[ISAKMP_NEXT_NONCE]->pbs; size_t len = pbs_left(nonce_pbs); if (len < MINIMUM_NONCE_SIZE || MAXIMUM_NONCE_SIZE < len) { loglog(RC_LOG_SERIOUS, "%s length not between %d and %d" , name , MINIMUM_NONCE_SIZE, MAXIMUM_NONCE_SIZE); return ISAKMP_PAYLOAD_MALFORMED; /* ??? */ } free(dest->ptr); *dest = chunk_create(nonce_pbs->cur, len); *dest = chunk_clone(*dest); return ISAKMP_NOTHING_WRONG; } /* encrypt message, sans fixed part of header * IV is fetched from st->st_new_iv and stored into st->st_iv. * The theory is that there will be no "backing out", so we commit to IV. * We also close the pbs. */ bool encrypt_message(pb_stream *pbs, struct state *st) { u_int8_t *enc_start = pbs->start + sizeof(struct isakmp_hdr); size_t enc_len = pbs_offset(pbs) - sizeof(struct isakmp_hdr); chunk_t data, iv; char *new_iv; size_t crypter_block_size; encryption_algorithm_t enc_alg; crypter_t *crypter; DBG_cond_dump(DBG_CRYPT | DBG_RAW, "encrypting:\n", enc_start, enc_len); enc_alg = oakley_to_encryption_algorithm(st->st_oakley.encrypt); crypter = lib->crypto->create_crypter(lib->crypto, enc_alg, st->st_enc_key.len); crypter_block_size = crypter->get_block_size(crypter); /* Pad up to multiple of encryption blocksize. * See the description associated with the definition of * struct isakmp_hdr in packet.h. */ { size_t padding = pad_up(enc_len, crypter_block_size); if (padding != 0) { if (!out_zero(padding, pbs, "encryption padding")) return FALSE; enc_len += padding; } } DBG(DBG_CRYPT, DBG_log("encrypting using %s", enum_show(&oakley_enc_names, st->st_oakley.encrypt))); data = chunk_create(enc_start, enc_len); /* form iv by truncation */ st->st_new_iv_len = crypter_block_size; iv = chunk_create(st->st_new_iv, st->st_new_iv_len); crypter->set_key(crypter, st->st_enc_key); crypter->encrypt(crypter, data, iv, NULL); crypter->destroy(crypter); new_iv = data.ptr + data.len - crypter_block_size; memcpy(st->st_new_iv, new_iv, crypter_block_size); update_iv(st); DBG_cond_dump(DBG_CRYPT, "next IV:", st->st_iv, st->st_iv_len); close_message(pbs); return TRUE; } /* Compute HASH(1), HASH(2) of Quick Mode. * HASH(1) is part of Quick I1 message. * HASH(2) is part of Quick R1 message. * Used by: quick_outI1, quick_inI1_outR1 (twice), quick_inR1_outI2 * (see RFC 2409 "IKE" 5.5, pg. 18 or draft-ietf-ipsec-ike-01.txt 6.2 pg 25) */ static size_t quick_mode_hash12(u_char *dest, u_char *start, u_char *roof, const struct state *st, const msgid_t *msgid, bool hash2) { chunk_t msgid_chunk = chunk_from_thing(*msgid); chunk_t msg_chunk = { start, roof - start }; pseudo_random_function_t prf_alg; prf_t *prf; size_t prf_block_size; prf_alg = oakley_to_prf(st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, st->st_skeyid_a); prf->get_bytes(prf, msgid_chunk, NULL); if (hash2) { prf->get_bytes(prf, st->st_ni, NULL); /* include Ni_b in the hash */ } prf->get_bytes(prf, msg_chunk, dest); prf_block_size = prf->get_block_size(prf); prf->destroy(prf); DBG(DBG_CRYPT, DBG_log("HASH(%d) computed:", hash2 + 1); DBG_dump("", dest, prf_block_size) ) return prf_block_size; } /* Compute HASH(3) in Quick Mode (part of Quick I2 message). * Used by: quick_inR1_outI2, quick_inI2 * See RFC2409 "The Internet Key Exchange (IKE)" 5.5. * NOTE: this hash (unlike HASH(1) and HASH(2)) ONLY covers the * Message ID and Nonces. This is a mistake. */ static size_t quick_mode_hash3(u_char *dest, struct state *st) { chunk_t seed_chunk = chunk_from_chars(0x00); chunk_t msgid_chunk = chunk_from_thing(st->st_msgid); pseudo_random_function_t prf_alg; prf_t *prf; size_t prf_block_size; prf_alg = oakley_to_prf(st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, st->st_skeyid_a); prf->get_bytes(prf, seed_chunk, NULL ); prf->get_bytes(prf, msgid_chunk, NULL); prf->get_bytes(prf, st->st_ni, NULL); prf->get_bytes(prf, st->st_nr, dest); prf_block_size = prf->get_block_size(prf); prf->destroy(prf); DBG_cond_dump(DBG_CRYPT, "HASH(3) computed:", dest, prf_block_size); return prf_block_size; } /* Compute Phase 2 IV. * Uses Phase 1 IV from st_iv; puts result in st_new_iv. */ void init_phase2_iv(struct state *st, const msgid_t *msgid) { chunk_t iv_chunk = { st->st_ph1_iv, st->st_ph1_iv_len }; chunk_t msgid_chunk = chunk_from_thing(*msgid); hash_algorithm_t hash_alg; hasher_t *hasher; hash_alg = oakley_to_hash_algorithm(st->st_oakley.hash); hasher = lib->crypto->create_hasher(lib->crypto, hash_alg); DBG_cond_dump(DBG_CRYPT, "last Phase 1 IV:", st->st_ph1_iv, st->st_ph1_iv_len); st->st_new_iv_len = hasher->get_hash_size(hasher); passert(st->st_new_iv_len <= sizeof(st->st_new_iv)); hasher->get_hash(hasher, iv_chunk, NULL); hasher->get_hash(hasher, msgid_chunk, st->st_new_iv); hasher->destroy(hasher); DBG_cond_dump(DBG_CRYPT, "computed Phase 2 IV:", st->st_new_iv, st->st_new_iv_len); } /* Initiate quick mode. * --> HDR*, HASH(1), SA, Nr [, KE ] [, IDci, IDcr ] * (see RFC 2409 "IKE" 5.5) * Note: this is not called from demux.c */ static bool emit_subnet_id(ip_subnet *net, u_int8_t np, u_int8_t protoid, u_int16_t port, pb_stream *outs) { struct isakmp_ipsec_id id; pb_stream id_pbs; ip_address ta; const unsigned char *tbp; size_t tal; id.isaiid_np = np; id.isaiid_idtype = subnetishost(net) ? aftoinfo(subnettypeof(net))->id_addr : aftoinfo(subnettypeof(net))->id_subnet; id.isaiid_protoid = protoid; id.isaiid_port = port; if (!out_struct(&id, &isakmp_ipsec_identification_desc, outs, &id_pbs)) { return FALSE; } networkof(net, &ta); tal = addrbytesptr(&ta, &tbp); if (!out_raw(tbp, tal, &id_pbs, "client network")) { return FALSE; } if (!subnetishost(net)) { maskof(net, &ta); tal = addrbytesptr(&ta, &tbp); if (!out_raw(tbp, tal, &id_pbs, "client mask")) { return FALSE; } } close_output_pbs(&id_pbs); return TRUE; } stf_status quick_outI1(int whack_sock, struct state *isakmp_sa, connection_t *c, lset_t policy, unsigned long try, so_serial_t replacing) { struct state *st = duplicate_state(isakmp_sa); pb_stream reply; /* not really a reply */ pb_stream rbody; u_char /* set by START_HASH_PAYLOAD: */ *r_hashval, /* where in reply to jam hash value */ *r_hash_start; /* start of what is to be hashed */ bool has_client = c->spd.this.has_client || c->spd.that.has_client || c->spd.this.protocol || c->spd.that.protocol || c->spd.this.port || c->spd.that.port; bool send_natoa = FALSE; u_int8_t np = ISAKMP_NEXT_NONE; if (c->spd.this.modecfg && !c->spd.this.has_client && isanyaddr(&c->spd.this.host_srcip)) { connection_t *ph1_c = isakmp_sa->st_connection; if (ph1_c->spd.this.modecfg && !isanyaddr(&ph1_c->spd.this.host_srcip)) { char srcip[ADDRTOT_BUF]; c->spd.this.host_srcip = ph1_c->spd.this.host_srcip; c->spd.this.client = ph1_c->spd.this.client; c->spd.this.has_client = TRUE; addrtot(&c->spd.this.host_srcip, 0, srcip, sizeof(srcip)); plog("inheriting virtual IP source address %s from ModeCfg", srcip); } } st->st_whack_sock = whack_sock; st->st_connection = c; set_cur_state(st); /* we must reset before exit */ st->st_policy = policy; st->st_try = try; st->st_myuserprotoid = c->spd.this.protocol; st->st_peeruserprotoid = c->spd.that.protocol; st->st_myuserport = c->spd.this.port; st->st_peeruserport = c->spd.that.port; st->st_msgid = generate_msgid(isakmp_sa); st->st_state = STATE_QUICK_I1; insert_state(st); /* needs cookies, connection, and msgid */ if (replacing == SOS_NOBODY) { plog("initiating Quick Mode %s {using isakmp#%lu}", prettypolicy(policy), isakmp_sa->st_serialno); } else { plog("initiating Quick Mode %s to replace #%lu {using isakmp#%lu}", prettypolicy(policy), replacing, isakmp_sa->st_serialno); } if (isakmp_sa->nat_traversal & NAT_T_DETECTED) { /* Duplicate nat_traversal status in new state */ st->nat_traversal = isakmp_sa->nat_traversal; if (isakmp_sa->nat_traversal & LELEM(NAT_TRAVERSAL_NAT_BHND_ME)) { has_client = TRUE; } nat_traversal_change_port_lookup(NULL, st); } else { st->nat_traversal = 0; } /* are we going to send a NAT-OA payload? */ if ((st->nat_traversal & NAT_T_WITH_NATOA) && !(st->st_policy & POLICY_TUNNEL) && (st->nat_traversal & LELEM(NAT_TRAVERSAL_NAT_BHND_ME))) { send_natoa = TRUE; np = (st->nat_traversal & NAT_T_WITH_RFC_VALUES) ? ISAKMP_NEXT_NATOA_RFC : ISAKMP_NEXT_NATOA_DRAFTS; } /* set up reply */ init_pbs(&reply, reply_buffer, sizeof(reply_buffer), "reply packet"); /* HDR* out */ { struct isakmp_hdr hdr; hdr.isa_version = ISAKMP_MAJOR_VERSION << ISA_MAJ_SHIFT | ISAKMP_MINOR_VERSION; hdr.isa_np = ISAKMP_NEXT_HASH; hdr.isa_xchg = ISAKMP_XCHG_QUICK; hdr.isa_msgid = st->st_msgid; hdr.isa_flags = ISAKMP_FLAG_ENCRYPTION; memcpy(hdr.isa_icookie, st->st_icookie, COOKIE_SIZE); memcpy(hdr.isa_rcookie, st->st_rcookie, COOKIE_SIZE); if (!out_struct(&hdr, &isakmp_hdr_desc, &reply, &rbody)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* HASH(1) -- create and note space to be filled later */ START_HASH_PAYLOAD(rbody, ISAKMP_NEXT_SA); /* SA out */ /* * See if pfs_group has been specified for this conn, * if not, fallback to old use-same-as-P1 behaviour */ #ifndef NO_IKE_ALG if (st->st_connection) { st->st_pfs_group = ike_alg_pfsgroup(st->st_connection, policy); } if (!st->st_pfs_group) #endif /* If PFS specified, use the same group as during Phase 1: * since no negotiation is possible, we pick one that is * very likely supported. */ st->st_pfs_group = policy & POLICY_PFS? isakmp_sa->st_oakley.group : NULL; /* Emit SA payload based on a subset of the policy bits. * POLICY_COMPRESS is considered iff we can do IPcomp. */ { lset_t pm = POLICY_ENCRYPT | POLICY_AUTHENTICATE; if (can_do_IPcomp) { pm |= POLICY_COMPRESS; } if (!out_sa(&rbody, &ipsec_sadb[(st->st_policy & pm) >> POLICY_IPSEC_SHIFT], st, FALSE, ISAKMP_NEXT_NONCE)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* Ni out */ if (!build_and_ship_nonce(&st->st_ni, &rbody , policy & POLICY_PFS? ISAKMP_NEXT_KE : has_client? ISAKMP_NEXT_ID : np , "Ni")) { reset_cur_state(); return STF_INTERNAL_ERROR; } /* [ KE ] out (for PFS) */ if (st->st_pfs_group != NULL) { if (!build_and_ship_KE(st, &st->st_gi, st->st_pfs_group , &rbody, has_client? ISAKMP_NEXT_ID : np)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* [ IDci, IDcr ] out */ if (has_client) { /* IDci (we are initiator), then IDcr (peer is responder) */ if (!emit_subnet_id(&c->spd.this.client , ISAKMP_NEXT_ID, st->st_myuserprotoid, st->st_myuserport, &rbody) || !emit_subnet_id(&c->spd.that.client , np, st->st_peeruserprotoid, st->st_peeruserport, &rbody)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* Send NAT-OA if our address is NATed */ if (send_natoa) { if (!nat_traversal_add_natoa(ISAKMP_NEXT_NONE, &rbody, st)) { reset_cur_state(); return STF_INTERNAL_ERROR; } } /* finish computing HASH(1), inserting it in output */ (void) quick_mode_hash12(r_hashval, r_hash_start, rbody.cur , st, &st->st_msgid, FALSE); /* encrypt message, except for fixed part of header */ init_phase2_iv(isakmp_sa, &st->st_msgid); st->st_new_iv_len = isakmp_sa->st_new_iv_len; memcpy(st->st_new_iv, isakmp_sa->st_new_iv, st->st_new_iv_len); if (!encrypt_message(&rbody, st)) { reset_cur_state(); return STF_INTERNAL_ERROR; } /* save packet, now that we know its size */ st->st_tpacket = chunk_create(reply.start, pbs_offset(&reply)); st->st_tpacket = chunk_clone(st->st_tpacket); /* send the packet */ send_packet(st, "quick_outI1"); delete_event(st); event_schedule(EVENT_RETRANSMIT, EVENT_RETRANSMIT_DELAY_0, st); if (replacing == SOS_NOBODY) { whack_log(RC_NEW_STATE + STATE_QUICK_I1 , "%s: initiate" , enum_name(&state_names, st->st_state)); } else { whack_log(RC_NEW_STATE + STATE_QUICK_I1 , "%s: initiate to replace #%lu" , enum_name(&state_names, st->st_state) , replacing); } reset_cur_state(); return STF_OK; } /* * Decode the CERT payload of Phase 1. */ static void decode_cert(struct msg_digest *md) { struct payload_digest *p; for (p = md->chain[ISAKMP_NEXT_CERT]; p != NULL; p = p->next) { struct isakmp_cert *const cert = &p->payload.cert; chunk_t blob; time_t valid_until; blob.ptr = p->pbs.cur; blob.len = pbs_left(&p->pbs); if (cert->isacert_type == CERT_X509_SIGNATURE) { cert_t x509cert = cert_empty; x509cert.cert = lib->creds->create(lib->creds, CRED_CERTIFICATE, CERT_X509, BUILD_BLOB_ASN1_DER, blob, BUILD_END); if (x509cert.cert) { if (verify_x509cert(&x509cert, strict_crl_policy, &valid_until)) { DBG(DBG_PARSING, DBG_log("Public key validated") ) add_public_key_from_cert(&x509cert, valid_until, DAL_SIGNED); } else { plog("X.509 certificate rejected"); } x509cert.cert->destroy(x509cert.cert); } else { plog("Syntax error in X.509 certificate"); } } else if (cert->isacert_type == CERT_PKCS7_WRAPPED_X509) { linked_list_t *certs = linked_list_create(); if (pkcs7_parse_signedData(blob, NULL, certs, NULL, NULL)) { store_x509certs(certs, strict_crl_policy); } else { plog("Syntax error in PKCS#7 wrapped X.509 certificates"); } certs->destroy_offset(certs, offsetof(certificate_t, destroy)); } else { loglog(RC_LOG_SERIOUS, "ignoring %s certificate payload", enum_show(&cert_type_names, cert->isacert_type)); DBG_cond_dump_chunk(DBG_PARSING, "CERT:\n", blob); } } } /* * Decode the CR payload of Phase 1. */ static void decode_cr(struct msg_digest *md, connection_t *c) { struct payload_digest *p; for (p = md->chain[ISAKMP_NEXT_CR]; p != NULL; p = p->next) { struct isakmp_cr *const cr = &p->payload.cr; chunk_t ca_name; ca_name.len = pbs_left(&p->pbs); ca_name.ptr = (ca_name.len > 0)? p->pbs.cur : NULL; DBG_cond_dump_chunk(DBG_PARSING, "CR", ca_name); if (cr->isacr_type == CERT_X509_SIGNATURE) { if (ca_name.len > 0) { identification_t *ca; if (!is_asn1(ca_name)) { continue; } if (c->requested_ca == NULL) { c->requested_ca = linked_list_create(); } ca = identification_create_from_encoding(ID_DER_ASN1_DN, ca_name); c->requested_ca->insert_last(c->requested_ca, ca); DBG(DBG_PARSING | DBG_CONTROL, DBG_log("requested CA: \"%Y\"", ca) ) } else { DBG(DBG_PARSING | DBG_CONTROL, DBG_log("requested CA: %%any") ) } c->got_certrequest = TRUE; } else { loglog(RC_LOG_SERIOUS, "ignoring %s certificate request payload", enum_show(&cert_type_names, cr->isacr_type)); } } } /* Decode the ID payload of Phase 1 (main_inI3_outR3 and main_inR3) * Note: we may change connections as a result. * We must be called before SIG or HASH are decoded since we * may change the peer's public key or ID. */ static bool decode_peer_id(struct msg_digest *md, identification_t **peer) { struct state *const st = md->st; struct payload_digest *const id_pld = md->chain[ISAKMP_NEXT_ID]; const pb_stream *const id_pbs = &id_pld->pbs; struct isakmp_id *const id = &id_pld->payload.id; chunk_t id_payload; /* I think that RFC2407 (IPSEC DOI) 4.6.2 is confused. * It talks about the protocol ID and Port fields of the ID * Payload, but they don't exist as such in Phase 1. * We use more appropriate names. * isaid_doi_specific_a is in place of Protocol ID. * isaid_doi_specific_b is in place of Port. * Besides, there is no good reason for allowing these to be * other than 0 in Phase 1. */ if ((st->nat_traversal & NAT_T_WITH_PORT_FLOATING) && id->isaid_doi_specific_a == IPPROTO_UDP && (id->isaid_doi_specific_b == 0 || id->isaid_doi_specific_b == NAT_T_IKE_FLOAT_PORT)) { DBG_log("protocol/port in Phase 1 ID Payload is %d/%d. " "accepted with port_floating NAT-T", id->isaid_doi_specific_a, id->isaid_doi_specific_b); } else if (!(id->isaid_doi_specific_a == 0 && id->isaid_doi_specific_b == 0) && !(id->isaid_doi_specific_a == IPPROTO_UDP && id->isaid_doi_specific_b == IKE_UDP_PORT)) { loglog(RC_LOG_SERIOUS, "protocol/port in Phase 1 ID Payload must be 0/0 or %d/%d" " but are %d/%d" , IPPROTO_UDP, IKE_UDP_PORT , id->isaid_doi_specific_a, id->isaid_doi_specific_b); return FALSE; } id_payload = chunk_create(id_pbs->cur, pbs_left(id_pbs)); switch (id->isaid_idtype) { case ID_IPV4_ADDR: if (id_payload.len != 4) { loglog(RC_LOG_SERIOUS, "improper %s Phase 1 ID payload", enum_show(&ident_names, id->isaid_idtype)); return FALSE; } break; case ID_IPV6_ADDR: if (id_payload.len != 16) { loglog(RC_LOG_SERIOUS, "improper %s Phase 1 ID payload", enum_show(&ident_names, id->isaid_idtype)); return FALSE; } break; case ID_USER_FQDN: case ID_FQDN: if (memchr(id_payload.ptr, '\0', id_payload.len) != NULL) { loglog(RC_LOG_SERIOUS, "%s Phase 1 ID payload contains " "a NUL character", enum_show(&ident_names, id->isaid_idtype)); return FALSE; } break; case ID_KEY_ID: case ID_DER_ASN1_DN: break; default: /* XXX Could send notification back */ loglog(RC_LOG_SERIOUS, "unacceptable identity type (%s) " "in Phase 1 ID payload", enum_show(&ident_names, id->isaid_idtype)); return FALSE; } *peer = identification_create_from_encoding(id->isaid_idtype, id_payload); plog("Peer ID is %s: '%Y'", enum_show(&ident_names, id->isaid_idtype), *peer); /* check for certificates */ decode_cert(md); return TRUE; } /* Now that we've decoded the ID payload, let's see if we * need to switch connections. * We must not switch horses if we initiated: * - if the initiation was explicit, we'd be ignoring user's intent * - if opportunistic, we'll lose our HOLD info */ static bool switch_connection(struct msg_digest *md, identification_t *peer, bool initiator) { struct state *const st = md->st; connection_t *c = st->st_connection; identification_t *peer_ca; peer_ca = st->st_peer_pubkey ? st->st_peer_pubkey->issuer : NULL; if (peer_ca) { DBG(DBG_CONTROL, DBG_log("peer CA: \"%Y\"", peer_ca) ) } else { DBG(DBG_CONTROL, DBG_log("peer CA: %%none") ) } if (initiator) { int pathlen; if (!peer->equals(peer, c->spd.that.id)) { loglog(RC_LOG_SERIOUS, "we require peer to have ID '%Y', but peer declares '%Y'", c->spd.that.id, peer); return FALSE; } if (c->spd.that.ca) { DBG(DBG_CONTROL, DBG_log("required CA: \"%s\"", c->spd.that.ca); ) } else { DBG(DBG_CONTROL, DBG_log("required CA: %%none"); ) } if (!trusted_ca(peer_ca, c->spd.that.ca, &pathlen)) { loglog(RC_LOG_SERIOUS , "we don't accept the peer's CA"); return FALSE; } } else { connection_t *r; /* check for certificate requests */ decode_cr(md, c); r = refine_host_connection(st, peer, peer_ca); /* delete the collected certificate requests */ if (c->requested_ca) { c->requested_ca->destroy_offset(c->requested_ca, offsetof(identification_t, destroy)); c->requested_ca = NULL; } if (r == NULL) { loglog(RC_LOG_SERIOUS, "no suitable connection for peer '%Y'", peer); return FALSE; } if (r->spd.this.ca) { DBG(DBG_CONTROL, DBG_log("offered CA: \"%Y\"", r->spd.this.ca) ) } else { DBG(DBG_CONTROL, DBG_log("offered CA: %%none") ) } if (r != c) { /* apparently, r is an improvement on c -- replace */ DBG(DBG_CONTROL , DBG_log("switched from \"%s\" to \"%s\"", c->name, r->name)); if (r->kind == CK_TEMPLATE) { /* instantiate it, filling in peer's ID */ r = rw_instantiate(r, &c->spd.that.host_addr , c->spd.that.host_port, NULL, peer); } /* copy certificate request info */ r->got_certrequest = c->got_certrequest; st->st_connection = r; /* kill reference to c */ set_cur_connection(r); connection_discard(c); } else if (c->spd.that.has_id_wildcards) { c->spd.that.id->destroy(c->spd.that.id); c->spd.that.id = peer->clone(peer); c->spd.that.has_id_wildcards = FALSE; } } return TRUE; } /* Decode the variable part of an ID packet (during Quick Mode). * This is designed for packets that identify clients, not peers. * Rejects 0.0.0.0/32 or IPv6 equivalent because * (1) it is wrong and (2) we use this value for inband signalling. */ static bool decode_net_id(struct isakmp_ipsec_id *id, pb_stream *id_pbs, ip_subnet *net, const char *which) { const struct af_info *afi = NULL; /* Note: the following may be a pointer into static memory * that may be recycled, but only if the type is not known. * That case is disposed of very early -- in the first switch. */ const char *idtypename = enum_show(&ident_names, id->isaiid_idtype); switch (id->isaiid_idtype) { case ID_IPV4_ADDR: case ID_IPV4_ADDR_SUBNET: case ID_IPV4_ADDR_RANGE: afi = &af_inet4_info; break; case ID_IPV6_ADDR: case ID_IPV6_ADDR_SUBNET: case ID_IPV6_ADDR_RANGE: afi = &af_inet6_info; break; case ID_FQDN: return TRUE; default: /* XXX support more */ loglog(RC_LOG_SERIOUS, "unsupported ID type %s" , idtypename); /* XXX Could send notification back */ return FALSE; } switch (id->isaiid_idtype) { case ID_IPV4_ADDR: case ID_IPV6_ADDR: { ip_address temp_address; err_t ugh; ugh = initaddr(id_pbs->cur, pbs_left(id_pbs), afi->af, &temp_address); if (ugh != NULL) { loglog(RC_LOG_SERIOUS, "%s ID payload %s has wrong length in Quick I1 (%s)" , which, idtypename, ugh); /* XXX Could send notification back */ return FALSE; } if (isanyaddr(&temp_address)) { loglog(RC_LOG_SERIOUS, "%s ID payload %s is invalid (%s) in Quick I1" , which, idtypename, ip_str(&temp_address)); /* XXX Could send notification back */ return FALSE; } happy(addrtosubnet(&temp_address, net)); DBG(DBG_PARSING | DBG_CONTROL , DBG_log("%s is %s", which, ip_str(&temp_address))); break; } case ID_IPV4_ADDR_SUBNET: case ID_IPV6_ADDR_SUBNET: { ip_address temp_address, temp_mask; err_t ugh; if (pbs_left(id_pbs) != 2 * afi->ia_sz) { loglog(RC_LOG_SERIOUS, "%s ID payload %s wrong length in Quick I1" , which, idtypename); /* XXX Could send notification back */ return FALSE; } ugh = initaddr(id_pbs->cur , afi->ia_sz, afi->af, &temp_address); if (ugh == NULL) { ugh = initaddr(id_pbs->cur + afi->ia_sz , afi->ia_sz, afi->af, &temp_mask); } if (ugh == NULL) { ugh = initsubnet(&temp_address, masktocount(&temp_mask) , '0', net); } if (ugh == NULL && subnetisnone(net)) { ugh = "contains only anyaddr"; } if (ugh != NULL) { loglog(RC_LOG_SERIOUS, "%s ID payload %s bad subnet in Quick I1 (%s)" , which, idtypename, ugh); /* XXX Could send notification back */ return FALSE; } DBG(DBG_PARSING | DBG_CONTROL, { char temp_buff[SUBNETTOT_BUF]; subnettot(net, 0, temp_buff, sizeof(temp_buff)); DBG_log("%s is subnet %s", which, temp_buff); }); break; } case ID_IPV4_ADDR_RANGE: case ID_IPV6_ADDR_RANGE: { ip_address temp_address_from, temp_address_to; err_t ugh; if (pbs_left(id_pbs) != 2 * afi->ia_sz) { loglog(RC_LOG_SERIOUS, "%s ID payload %s wrong length in Quick I1" , which, idtypename); /* XXX Could send notification back */ return FALSE; } ugh = initaddr(id_pbs->cur, afi->ia_sz, afi->af, &temp_address_from); if (ugh == NULL) { ugh = initaddr(id_pbs->cur + afi->ia_sz , afi->ia_sz, afi->af, &temp_address_to); } if (ugh != NULL) { loglog(RC_LOG_SERIOUS, "%s ID payload %s malformed (%s) in Quick I1" , which, idtypename, ugh); /* XXX Could send notification back */ return FALSE; } ugh = rangetosubnet(&temp_address_from, &temp_address_to, net); if (ugh == NULL && subnetisnone(net)) { ugh = "contains only anyaddr"; } if (ugh != NULL) { char temp_buff1[ADDRTOT_BUF], temp_buff2[ADDRTOT_BUF]; addrtot(&temp_address_from, 0, temp_buff1, sizeof(temp_buff1)); addrtot(&temp_address_to, 0, temp_buff2, sizeof(temp_buff2)); loglog(RC_LOG_SERIOUS, "%s ID payload in Quick I1, %s" " %s - %s unacceptable: %s" , which, idtypename, temp_buff1, temp_buff2, ugh); return FALSE; } DBG(DBG_PARSING | DBG_CONTROL, { char temp_buff[SUBNETTOT_BUF]; subnettot(net, 0, temp_buff, sizeof(temp_buff)); DBG_log("%s is subnet %s (received as range)" , which, temp_buff); }); break; } } /* set the port selector */ setportof(htons(id->isaiid_port), &net->addr); DBG(DBG_PARSING | DBG_CONTROL, DBG_log("%s protocol/port is %d/%d", which, id->isaiid_protoid, id->isaiid_port) ) return TRUE; } /* like decode, but checks that what is received matches what was sent */ static bool check_net_id(struct isakmp_ipsec_id *id, pb_stream *id_pbs, u_int8_t *protoid, u_int16_t *port, ip_subnet *net, const char *which) { ip_subnet net_temp; if (!decode_net_id(id, id_pbs, &net_temp, which)) { return FALSE; } if (!samesubnet(net, &net_temp) || *protoid != id->isaiid_protoid || *port != id->isaiid_port) { loglog(RC_LOG_SERIOUS, "%s ID returned doesn't match my proposal", which); return FALSE; } return TRUE; } /* * look for the existence of a non-expiring preloaded public key */ static bool has_preloaded_public_key(struct state *st) { connection_t *c = st->st_connection; /* do not consider rw connections since * the peer's identity must be known */ if (c->kind == CK_PERMANENT) { pubkey_list_t *p; /* look for a matching RSA public key */ for (p = pubkeys; p != NULL; p = p->next) { pubkey_t *key = p->key; key_type_t type = key->public_key->get_type(key->public_key); if (type == KEY_RSA && c->spd.that.id->equals(c->spd.that.id, key->id) && key->until_time == UNDEFINED_TIME) { /* found a preloaded public key */ return TRUE; } } } return FALSE; } /* * Produce the new key material of Quick Mode. * RFC 2409 "IKE" section 5.5 * specifies how this is to be done. */ static void compute_proto_keymat(struct state *st, u_int8_t protoid, struct ipsec_proto_info *pi) { size_t needed_len = 0; /* bytes of keying material needed */ /* Add up the requirements for keying material * (It probably doesn't matter if we produce too much!) */ switch (protoid) { case PROTO_IPSEC_ESP: { needed_len = kernel_alg_esp_enc_keylen(pi->attrs.transid); if (needed_len && pi->attrs.key_len) { needed_len = pi->attrs.key_len / BITS_PER_BYTE; } switch (pi->attrs.transid) { case ESP_NULL: needed_len = 0; break; case ESP_AES_CCM_8: case ESP_AES_CCM_12: case ESP_AES_CCM_16: needed_len += 3; break; case ESP_AES_GCM_8: case ESP_AES_GCM_12: case ESP_AES_GCM_16: case ESP_AES_CTR: needed_len += 4; break; default: if (needed_len == 0) { bad_case(pi->attrs.transid); } } if (kernel_alg_esp_auth_ok(pi->attrs.auth, NULL)) { needed_len += kernel_alg_esp_auth_keylen(pi->attrs.auth); } else { switch (pi->attrs.auth) { case AUTH_ALGORITHM_NONE: break; case AUTH_ALGORITHM_HMAC_MD5: needed_len += HMAC_MD5_KEY_LEN; break; case AUTH_ALGORITHM_HMAC_SHA1: needed_len += HMAC_SHA1_KEY_LEN; break; case AUTH_ALGORITHM_DES_MAC: default: bad_case(pi->attrs.auth); } } break; } case PROTO_IPSEC_AH: { switch (pi->attrs.transid) { case AH_MD5: needed_len = HMAC_MD5_KEY_LEN; break; case AH_SHA: needed_len = HMAC_SHA1_KEY_LEN; break; default: bad_case(pi->attrs.transid); } break; } default: bad_case(protoid); } pi->keymat_len = needed_len; /* Allocate space for the keying material. Although only needed_len bytes * are desired, we must round up to a multiple of hash_size * so that our buffer isn't overrun. */ { size_t needed_space; /* space needed for keying material (rounded up) */ size_t i, prf_block_size; chunk_t protoid_chunk = chunk_from_thing(protoid); chunk_t spi_our = chunk_from_thing(pi->our_spi); chunk_t spi_peer = chunk_from_thing(pi->attrs.spi); pseudo_random_function_t prf_alg; prf_t *prf_our, *prf_peer; prf_alg = oakley_to_prf(st->st_oakley.hash); prf_our = lib->crypto->create_prf(lib->crypto, prf_alg); prf_peer = lib->crypto->create_prf(lib->crypto, prf_alg); prf_our->set_key(prf_our, st->st_skeyid_d); prf_peer->set_key(prf_peer, st->st_skeyid_d); prf_block_size = prf_our->get_block_size(prf_our); needed_space = needed_len + pad_up(needed_len, prf_block_size); replace(pi->our_keymat, malloc(needed_space)); replace(pi->peer_keymat, malloc(needed_space)); for (i = 0;; ) { char *keymat_i_our = pi->our_keymat + i; char *keymat_i_peer = pi->peer_keymat + i; chunk_t keymat_our = { keymat_i_our, prf_block_size }; chunk_t keymat_peer = { keymat_i_peer, prf_block_size }; if (st->st_shared.ptr != NULL) { /* PFS: include the g^xy */ prf_our->get_bytes(prf_our, st->st_shared, NULL); prf_peer->get_bytes(prf_peer, st->st_shared, NULL); } prf_our->get_bytes(prf_our, protoid_chunk, NULL); prf_peer->get_bytes(prf_peer, protoid_chunk, NULL); prf_our->get_bytes(prf_our, spi_our, NULL); prf_peer->get_bytes(prf_peer, spi_peer, NULL); prf_our->get_bytes(prf_our, st->st_ni, NULL); prf_peer->get_bytes(prf_peer, st->st_ni, NULL); prf_our->get_bytes(prf_our, st->st_nr, keymat_i_our); prf_peer->get_bytes(prf_peer, st->st_nr, keymat_i_peer); i += prf_block_size; if (i >= needed_space) { break; } /* more keying material needed: prepare to go around again */ prf_our->get_bytes(prf_our, keymat_our, NULL); prf_peer->get_bytes(prf_peer, keymat_peer, NULL); } prf_our->destroy(prf_our); prf_peer->destroy(prf_peer); } DBG(DBG_CRYPT, DBG_dump("KEYMAT computed:\n", pi->our_keymat, pi->keymat_len); DBG_dump("Peer KEYMAT computed:\n", pi->peer_keymat, pi->keymat_len)); } static void compute_keymats(struct state *st) { if (st->st_ah.present) { compute_proto_keymat(st, PROTO_IPSEC_AH, &st->st_ah); } if (st->st_esp.present) { compute_proto_keymat(st, PROTO_IPSEC_ESP, &st->st_esp); } } static bool uses_pubkey_auth(int auth) { switch (auth) { case OAKLEY_RSA_SIG: case OAKLEY_ECDSA_SIG: case OAKLEY_ECDSA_256: case OAKLEY_ECDSA_384: case OAKLEY_ECDSA_521: case XAUTHInitRSA: case XAUTHRespRSA: return TRUE; default: return FALSE; } } /* build an ID payload * Note: no memory is allocated for the body of the payload (tl->ptr). * We assume it will end up being a pointer into a sufficiently * stable datastructure. It only needs to last a short time. */ static void build_id_payload(struct isakmp_ipsec_id *hd, chunk_t *tl, struct end *end) { identification_t *id = resolve_myid(end->id); zero(hd); hd->isaiid_idtype = id->get_type(id); switch (id->get_type(id)) { case ID_ANY: hd->isaiid_idtype = aftoinfo(addrtypeof(&end->host_addr))->id_addr; tl->len = addrbytesptr(&end->host_addr, (const unsigned char **)&tl->ptr); /* sets tl->ptr too */ break; case ID_IPV4_ADDR: case ID_IPV6_ADDR: case ID_FQDN: case ID_USER_FQDN: case ID_DER_ASN1_DN: case ID_KEY_ID: *tl = id->get_encoding(id); break; default: bad_case(id->get_type(id)); } } /* State Transition Functions. * * The definition of state_microcode_table in demux.c is a good * overview of these routines. * * - Called from process_packet; result handled by complete_state_transition * - struct state_microcode member "processor" points to these * - these routine definitionss are in state order * - these routines must be restartable from any point of error return: * beware of memory allocated before any error. * - output HDR is usually emitted by process_packet (if state_microcode * member first_out_payload isn't ISAKMP_NEXT_NONE). * * The transition functions' functions include: * - process and judge payloads * - update st_iv (result of decryption is in st_new_iv) * - build reply packet */ /* Handle a Main Mode Oakley first packet (responder side). * HDR;SA --> HDR;SA */ stf_status main_inI1_outR1(struct msg_digest *md) { struct payload_digest *const sa_pd = md->chain[ISAKMP_NEXT_SA]; struct state *st; connection_t *c; struct isakmp_proposal proposal; pb_stream proposal_pbs; pb_stream r_sa_pbs; u_int32_t ipsecdoisit; lset_t policy = LEMPTY; int vids_to_send = 0; /* We preparse the peer's proposal in order to determine * the requested authentication policy (RSA or PSK) */ RETURN_STF_FAILURE(preparse_isakmp_sa_body(&sa_pd->payload.sa , &sa_pd->pbs, &ipsecdoisit, &proposal_pbs, &proposal)); backup_pbs(&proposal_pbs); RETURN_STF_FAILURE(parse_isakmp_policy(&proposal_pbs , proposal.isap_notrans, &policy)); restore_pbs(&proposal_pbs); /* We are only considering candidate connections that match * the requested authentication policy (RSA or PSK) */ c = find_host_connection(&md->iface->addr, pluto_port , &md->sender, md->sender_port, policy); if (c == NULL && md->iface->ike_float) { c = find_host_connection(&md->iface->addr, NAT_T_IKE_FLOAT_PORT , &md->sender, md->sender_port, policy); } if (c == NULL) { /* See if a wildcarded connection can be found. * We cannot pick the right connection, so we're making a guess. * All Road Warrior connections are fair game: * we pick the first we come across (if any). * If we don't find any, we pick the first opportunistic * with the smallest subnet that includes the peer. * There is, of course, no necessary relationship between * an Initiator's address and that of its client, * but Food Groups kind of assumes one. */ { connection_t *d; d = find_host_connection(&md->iface->addr , pluto_port, (ip_address*)NULL, md->sender_port, policy); for (; d != NULL; d = d->hp_next) { if (d->kind == CK_GROUP) { /* ignore */ } else { if (d->kind == CK_TEMPLATE && !(d->policy & POLICY_OPPO)) { /* must be Road Warrior: we have a winner */ c = d; break; } /* Opportunistic or Shunt: pick tightest match */ if (addrinsubnet(&md->sender, &d->spd.that.client) && (c == NULL || !subnetinsubnet(&c->spd.that.client, &d->spd.that.client))) c = d; } } } if (c == NULL) { loglog(RC_LOG_SERIOUS, "initial Main Mode message received on %s:%u" " but no connection has been authorized%s%s" , ip_str(&md->iface->addr), ntohs(portof(&md->iface->addr)) , (policy != LEMPTY) ? " with policy=" : "" , (policy != LEMPTY) ? bitnamesof(sa_policy_bit_names, policy) : ""); /* XXX notification is in order! */ return STF_IGNORE; } else if (c->kind != CK_TEMPLATE) { loglog(RC_LOG_SERIOUS, "initial Main Mode message received on %s:%u" " but \"%s\" forbids connection" , ip_str(&md->iface->addr), pluto_port, c->name); /* XXX notification is in order! */ return STF_IGNORE; } else { /* Create a temporary connection that is a copy of this one. * His ID isn't declared yet. */ c = rw_instantiate(c, &md->sender, md->sender_port, NULL, NULL); } } else if (c->kind == CK_TEMPLATE) { /* Create an instance * This is a rare case: wildcard peer ID but static peer IP address */ c = rw_instantiate(c, &md->sender, md->sender_port, NULL, c->spd.that.id); } /* Set up state */ md->st = st = new_state(); st->st_connection = c; set_cur_state(st); /* (caller will reset cur_state) */ st->st_try = 0; /* not our job to try again from start */ st->st_policy = c->policy & ~POLICY_IPSEC_MASK; /* only as accurate as connection */ memcpy(st->st_icookie, md->hdr.isa_icookie, COOKIE_SIZE); get_cookie(FALSE, st->st_rcookie, COOKIE_SIZE, &md->sender); insert_state(st); /* needs cookies, connection, and msgid (0) */ st->st_doi = ISAKMP_DOI_IPSEC; st->st_situation = SIT_IDENTITY_ONLY; /* We only support this */ if ((c->kind == CK_INSTANCE) && (c->spd.that.host_port != pluto_port)) { plog("responding to Main Mode from unknown peer %s:%u" , ip_str(&c->spd.that.host_addr), c->spd.that.host_port); } else if (c->kind == CK_INSTANCE) { plog("responding to Main Mode from unknown peer %s" , ip_str(&c->spd.that.host_addr)); } else { plog("responding to Main Mode"); } /* parse_isakmp_sa also spits out a winning SA into our reply, * so we have to build our md->reply and emit HDR before calling it. */ /* determine how many Vendor ID payloads we will be sending */ if (SEND_PLUTO_VID) { vids_to_send++; } if (SEND_CISCO_UNITY_VID) { vids_to_send++; } if (md->openpgp) { vids_to_send++; } if (SEND_XAUTH_VID) { vids_to_send++; } /* always send DPD Vendor ID */ vids_to_send++; if (md->nat_traversal_vid && nat_traversal_enabled) { vids_to_send++; } /* HDR out. * We can't leave this to comm_handle() because we must * fill in the cookie. */ { struct isakmp_hdr r_hdr = md->hdr; r_hdr.isa_flags &= ~ISAKMP_FLAG_COMMIT; /* we won't ever turn on this bit */ memcpy(r_hdr.isa_rcookie, st->st_rcookie, COOKIE_SIZE); r_hdr.isa_np = ISAKMP_NEXT_SA; if (!out_struct(&r_hdr, &isakmp_hdr_desc, &md->reply, &md->rbody)) return STF_INTERNAL_ERROR; } /* start of SA out */ { struct isakmp_sa r_sa = sa_pd->payload.sa; r_sa.isasa_np = vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE; if (!out_struct(&r_sa, &isakmp_sa_desc, &md->rbody, &r_sa_pbs)) return STF_INTERNAL_ERROR; } /* SA body in and out */ RETURN_STF_FAILURE(parse_isakmp_sa_body(ipsecdoisit, &proposal_pbs ,&proposal, &r_sa_pbs, st, FALSE)); /* if enabled send Pluto Vendor ID */ if (SEND_PLUTO_VID) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &md->rbody, VID_STRONGSWAN)) { return STF_INTERNAL_ERROR; } } /* if enabled send Cisco Unity Vendor ID */ if (SEND_CISCO_UNITY_VID) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &md->rbody, VID_CISCO_UNITY)) { return STF_INTERNAL_ERROR; } } /* * if the peer sent an OpenPGP Vendor ID we offer the same capability */ if (md->openpgp) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &md->rbody, VID_OPENPGP)) { return STF_INTERNAL_ERROR; } } /* Announce our ability to do eXtended AUTHentication to the peer */ if (SEND_XAUTH_VID) { if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &md->rbody, VID_MISC_XAUTH)) { return STF_INTERNAL_ERROR; } } /* Announce our ability to do Dead Peer Detection to the peer */ if (!out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &md->rbody, VID_MISC_DPD)) { return STF_INTERNAL_ERROR; } if (md->nat_traversal_vid && nat_traversal_enabled) { /* reply if NAT-Traversal draft is supported */ st->nat_traversal = nat_traversal_vid_to_method(md->nat_traversal_vid); if (st->nat_traversal && !out_vendorid(vids_to_send-- ? ISAKMP_NEXT_VID : ISAKMP_NEXT_NONE , &md->rbody, md->nat_traversal_vid)) { return STF_INTERNAL_ERROR; } } close_message(&md->rbody); /* save initiator SA for HASH */ free(st->st_p1isa.ptr); st->st_p1isa = chunk_create(sa_pd->pbs.start, pbs_room(&sa_pd->pbs)); st->st_p1isa = chunk_clone(st->st_p1isa); return STF_OK; } /* STATE_MAIN_I1: HDR, SA --> auth dependent * PSK_AUTH, DS_AUTH: --> HDR, KE, Ni * * The following are not yet implemented: * PKE_AUTH: --> HDR, KE, [ HASH(1), ] PubKey_r, PubKey_r * RPKE_AUTH: --> HDR, [ HASH(1), ] Pubkey_r, Ke_i, * Ke_i [,<Ke_i] * * We must verify that the proposal received matches one we sent. */ stf_status main_inR1_outI2(struct msg_digest *md) { struct state *const st = md->st; u_int8_t np = ISAKMP_NEXT_NONE; /* verify echoed SA */ { u_int32_t ipsecdoisit; pb_stream proposal_pbs; struct isakmp_proposal proposal; struct payload_digest *const sapd = md->chain[ISAKMP_NEXT_SA]; RETURN_STF_FAILURE(preparse_isakmp_sa_body(&sapd->payload.sa ,&sapd->pbs, &ipsecdoisit, &proposal_pbs, &proposal)); if (proposal.isap_notrans != 1) { loglog(RC_LOG_SERIOUS, "a single Transform is required in a selecting Oakley Proposal; found %u" , (unsigned)proposal.isap_notrans); RETURN_STF_FAILURE(ISAKMP_BAD_PROPOSAL_SYNTAX); } RETURN_STF_FAILURE(parse_isakmp_sa_body(ipsecdoisit , &proposal_pbs, &proposal, NULL, st, TRUE)); } if (nat_traversal_enabled && md->nat_traversal_vid) { st->nat_traversal = nat_traversal_vid_to_method(md->nat_traversal_vid); plog("enabling possible NAT-traversal with method %s" , bitnamesof(natt_type_bitnames, st->nat_traversal)); } if (st->nat_traversal & NAT_T_WITH_NATD) { np = (st->nat_traversal & NAT_T_WITH_RFC_VALUES) ? ISAKMP_NEXT_NATD_RFC : ISAKMP_NEXT_NATD_DRAFTS; } /**************** build output packet HDR;KE;Ni ****************/ /* HDR out. * We can't leave this to comm_handle() because the isa_np * depends on the type of Auth (eventually). */ echo_hdr(md, FALSE, ISAKMP_NEXT_KE); /* KE out */ if (!build_and_ship_KE(st, &st->st_gi, st->st_oakley.group , &md->rbody, ISAKMP_NEXT_NONCE)) { return STF_INTERNAL_ERROR; } #ifdef DEBUG /* Ni out */ if (!build_and_ship_nonce(&st->st_ni, &md->rbody , (cur_debugging & IMPAIR_BUST_MI2)? ISAKMP_NEXT_VID : np, "Ni")) { return STF_INTERNAL_ERROR; } if (cur_debugging & IMPAIR_BUST_MI2) { /* generate a pointless large VID payload to push message over MTU */ pb_stream vid_pbs; if (!out_generic(np, &isakmp_vendor_id_desc, &md->rbody, &vid_pbs)) { return STF_INTERNAL_ERROR; } if (!out_zero(1500 /*MTU?*/, &vid_pbs, "Filler VID")) { return STF_INTERNAL_ERROR; } close_output_pbs(&vid_pbs); } #else /* Ni out */ if (!build_and_ship_nonce(&st->st_ni, &md->rbody, np, "Ni")) { return STF_INTERNAL_ERROR; } #endif if (st->nat_traversal & NAT_T_WITH_NATD) { if (!nat_traversal_add_natd(ISAKMP_NEXT_NONE, &md->rbody, md)) { return STF_INTERNAL_ERROR; } } /* finish message */ close_message(&md->rbody); /* Reinsert the state, using the responder cookie we just received */ unhash_state(st); memcpy(st->st_rcookie, md->hdr.isa_rcookie, COOKIE_SIZE); insert_state(st); /* needs cookies, connection, and msgid (0) */ return STF_OK; } /* STATE_MAIN_R1: * PSK_AUTH, DS_AUTH: HDR, KE, Ni --> HDR, KE, Nr * * The following are not yet implemented: * PKE_AUTH: HDR, KE, [ HASH(1), ] PubKey_r, PubKey_r * --> HDR, KE, PubKey_i, PubKey_i * RPKE_AUTH: * HDR, [ HASH(1), ] Pubkey_r, Ke_i, Ke_i [,<Ke_i] * --> HDR, PubKey_i, Ke_r, Ke_r */ stf_status main_inI2_outR2(struct msg_digest *md) { struct state *const st = md->st; pb_stream *keyex_pbs = &md->chain[ISAKMP_NEXT_KE]->pbs; /* send CR if auth is RSA or ECDSA and no preloaded public key exists*/ bool pubkey_auth = uses_pubkey_auth(st->st_oakley.auth); bool send_cr = !no_cr_send && pubkey_auth && !has_preloaded_public_key(st); u_int8_t np = ISAKMP_NEXT_NONE; /* KE in */ RETURN_STF_FAILURE(accept_KE(&st->st_gi, "Gi", st->st_oakley.group, keyex_pbs)); /* Ni in */ RETURN_STF_FAILURE(accept_nonce(md, &st->st_ni, "Ni")); if (st->nat_traversal & NAT_T_WITH_NATD) { nat_traversal_natd_lookup(md); np = (st->nat_traversal & NAT_T_WITH_RFC_VALUES) ? ISAKMP_NEXT_NATD_RFC : ISAKMP_NEXT_NATD_DRAFTS; } if (st->nat_traversal) { nat_traversal_show_result(st->nat_traversal, md->sender_port); } if (st->nat_traversal & NAT_T_WITH_KA) { nat_traversal_new_ka_event(); } /* decode certificate requests */ st->st_connection->got_certrequest = FALSE; decode_cr(md, st->st_connection); /**************** build output packet HDR;KE;Nr ****************/ /* HDR out done */ /* KE out */ if (!build_and_ship_KE(st, &st->st_gr, st->st_oakley.group , &md->rbody, ISAKMP_NEXT_NONCE)) { return STF_INTERNAL_ERROR; } #ifdef DEBUG /* Nr out */ if (!build_and_ship_nonce(&st->st_nr, &md->rbody, (cur_debugging & IMPAIR_BUST_MR2)? ISAKMP_NEXT_VID : (send_cr? ISAKMP_NEXT_CR : np), "Nr")) { return STF_INTERNAL_ERROR; } if (cur_debugging & IMPAIR_BUST_MR2) { /* generate a pointless large VID payload to push message over MTU */ pb_stream vid_pbs; if (!out_generic((send_cr)? ISAKMP_NEXT_CR : np, &isakmp_vendor_id_desc, &md->rbody, &vid_pbs)) { return STF_INTERNAL_ERROR; } if (!out_zero(1500 /*MTU?*/, &vid_pbs, "Filler VID")) { return STF_INTERNAL_ERROR; } close_output_pbs(&vid_pbs); } #else /* Nr out */ if (!build_and_ship_nonce(&st->st_nr, &md->rbody, (send_cr)? ISAKMP_NEXT_CR : np, "Nr")) return STF_INTERNAL_ERROR; #endif /* CR out */ if (send_cr) { if (st->st_connection->kind == CK_PERMANENT) { identification_t *ca = st->st_connection->spd.that.ca; chunk_t cr = (ca) ? ca->get_encoding(ca) : chunk_empty; if (!build_and_ship_CR(CERT_X509_SIGNATURE, cr, &md->rbody, np)) { return STF_INTERNAL_ERROR; } } else { linked_list_t *list = collect_rw_ca_candidates(md); int count = list->get_count(list); bool error = FALSE; if (count) { enumerator_t *enumerator; identification_t *ca; enumerator = list->create_enumerator(list); while (enumerator->enumerate(enumerator, &ca)) { if (!build_and_ship_CR(CERT_X509_SIGNATURE, ca->get_encoding(ca), &md->rbody, --count ? ISAKMP_NEXT_CR : np)) { error = TRUE; break; } } enumerator->destroy(enumerator); } else { if (!build_and_ship_CR(CERT_X509_SIGNATURE, chunk_empty, &md->rbody, np)) { error = TRUE; } } list->destroy_offset(list, offsetof(identification_t, destroy)); if (error) { return STF_INTERNAL_ERROR; } } } if (st->nat_traversal & NAT_T_WITH_NATD) { if (!nat_traversal_add_natd(ISAKMP_NEXT_NONE, &md->rbody, md)) { return STF_INTERNAL_ERROR; } } /* finish message */ close_message(&md->rbody); /* next message will be encrypted, but not this one. * We could defer this calculation. */ compute_dh_shared(st, st->st_gi); if (!generate_skeyids_iv(st)) { return STF_FAIL + ISAKMP_AUTHENTICATION_FAILED; } update_iv(st); return STF_OK; } /* STATE_MAIN_I2: * SMF_PSK_AUTH: HDR, KE, Nr --> HDR*, IDi1, HASH_I * SMF_DS_AUTH: HDR, KE, Nr --> HDR*, IDi1, [ CERT, ] SIG_I * * The following are not yet implemented. * SMF_PKE_AUTH: HDR, KE, PubKey_i, PubKey_i * --> HDR*, HASH_I * SMF_RPKE_AUTH: HDR, PubKey_i, Ke_r, Ke_r * --> HDR*, HASH_I */ stf_status main_inR2_outI3(struct msg_digest *md) { struct state *const st = md->st; pb_stream *const keyex_pbs = &md->chain[ISAKMP_NEXT_KE]->pbs; pb_stream id_pbs; /* ID Payload; also used for hash calculation */ connection_t *c = st->st_connection; certpolicy_t cert_policy = c->spd.this.sendcert; cert_t *mycert = c->spd.this.cert; bool requested, send_cert, send_cr; bool pubkey_auth = uses_pubkey_auth(st->st_oakley.auth); int auth_payload = pubkey_auth ? ISAKMP_NEXT_SIG : ISAKMP_NEXT_HASH; /* KE in */ RETURN_STF_FAILURE(accept_KE(&st->st_gr, "Gr", st->st_oakley.group, keyex_pbs)); /* Nr in */ RETURN_STF_FAILURE(accept_nonce(md, &st->st_nr, "Nr")); /* decode certificate requests */ c->got_certrequest = FALSE; decode_cr(md, c); /* free collected certificate requests since as initiator * we don't heed them anyway */ if (c->requested_ca) { c->requested_ca->destroy_offset(c->requested_ca, offsetof(identification_t, destroy)); c->requested_ca = NULL; } /* send certificate if auth is RSA, we have one and we want * or are requested to send it */ requested = cert_policy == CERT_SEND_IF_ASKED && c->got_certrequest; send_cert = pubkey_auth && mycert && mycert->cert->get_type(mycert->cert) == CERT_X509 && (cert_policy == CERT_ALWAYS_SEND || requested); /* send certificate request if we don't have a preloaded RSA public key */ send_cr = !no_cr_send && send_cert && !has_preloaded_public_key(st); /* done parsing; initialize crypto */ compute_dh_shared(st, st->st_gr); if (!generate_skeyids_iv(st)) { return STF_FAIL + ISAKMP_AUTHENTICATION_FAILED; } if (st->nat_traversal & NAT_T_WITH_NATD) { nat_traversal_natd_lookup(md); } if (st->nat_traversal) { nat_traversal_show_result(st->nat_traversal, md->sender_port); } if (st->nat_traversal & NAT_T_WITH_KA) { nat_traversal_new_ka_event(); } /*************** build output packet HDR*;IDii;HASH/SIG_I ***************/ /* ??? NOTE: this is almost the same as main_inI3_outR3's code */ /* HDR* out done */ /* IDii out */ { struct isakmp_ipsec_id id_hd; chunk_t id_b; build_id_payload(&id_hd, &id_b, &c->spd.this); id_hd.isaiid_np = (send_cert)? ISAKMP_NEXT_CERT : auth_payload; if (!out_struct(&id_hd, &isakmp_ipsec_identification_desc, &md->rbody, &id_pbs) || !out_chunk(id_b, &id_pbs, "my identity")) { return STF_INTERNAL_ERROR; } close_output_pbs(&id_pbs); } /* CERT out */ if (pubkey_auth) { DBG(DBG_CONTROL, DBG_log("our certificate policy is %N", cert_policy_names, cert_policy) ) if (mycert && mycert->cert->get_type(mycert->cert) == CERT_X509) { const char *request_text = ""; if (cert_policy == CERT_SEND_IF_ASKED) { request_text = (send_cert)? "upon request":"without request"; } plog("we have a cert %s sending it %s" , send_cert? "and are":"but are not", request_text); } else { plog("we don't have a cert"); } } if (send_cert) { bool success; chunk_t cert_encoding; pb_stream cert_pbs; struct isakmp_cert cert_hd; cert_hd.isacert_np = (send_cr)? ISAKMP_NEXT_CR : ISAKMP_NEXT_SIG; cert_hd.isacert_type = CERT_X509_SIGNATURE; if (!out_struct(&cert_hd, &isakmp_ipsec_certificate_desc, &md->rbody, &cert_pbs)) { return STF_INTERNAL_ERROR; } cert_encoding = mycert->cert->get_encoding(mycert->cert); success = out_chunk(cert_encoding, &cert_pbs, "CERT"); free(cert_encoding.ptr); if (!success) { return STF_INTERNAL_ERROR; } close_output_pbs(&cert_pbs); } /* CR out */ if (send_cr) { identification_t *ca = st->st_connection->spd.that.ca; chunk_t cr = (ca) ? ca->get_encoding(ca) : chunk_empty; if (!build_and_ship_CR(CERT_X509_SIGNATURE, cr, &md->rbody, ISAKMP_NEXT_SIG)) { return STF_INTERNAL_ERROR; } } /* HASH_I or SIG_I out */ { chunk_t hash = chunk_alloca(MAX_DIGEST_LEN); main_mode_hash(st, &hash, TRUE, &id_pbs); if (auth_payload == ISAKMP_NEXT_HASH) { /* HASH_I out */ if (!out_generic_raw(ISAKMP_NEXT_NONE, &isakmp_hash_desc, &md->rbody, hash.ptr, hash.len, "HASH_I")) { return STF_INTERNAL_ERROR; } } else { /* SIG_I out */ u_char sig_val[RSA_MAX_OCTETS]; signature_scheme_t scheme; size_t sig_len; scheme = oakley_to_signature_scheme(st->st_oakley.auth); sig_len = sign_hash(scheme, c, sig_val, hash); if (sig_len == 0) { loglog(RC_LOG_SERIOUS, "unable to locate my private key for signature"); return STF_FAIL + ISAKMP_AUTHENTICATION_FAILED; } if (!out_generic_raw(ISAKMP_NEXT_NONE, &isakmp_signature_desc , &md->rbody, sig_val, sig_len, "SIG_I")) { return STF_INTERNAL_ERROR; } } } /* encrypt message, except for fixed part of header */ /* st_new_iv was computed by generate_skeyids_iv */ if (!encrypt_message(&md->rbody, st)) { return STF_INTERNAL_ERROR; /* ??? we may be partly committed */ } return STF_OK; } /* Shared logic for asynchronous lookup of DNS KEY records. * Used for STATE_MAIN_R2 and STATE_MAIN_I3. */ enum key_oppo_step { kos_null, kos_his_txt #ifdef USE_KEYRR , kos_his_key #endif }; struct key_continuation { struct adns_continuation ac; /* common prefix */ struct msg_digest *md; enum key_oppo_step step; bool failure_ok; err_t last_ugh; }; typedef stf_status (key_tail_fn)(struct msg_digest *md , struct key_continuation *kc); static void report_key_dns_failure(identification_t *id, err_t ugh) { loglog(RC_LOG_SERIOUS, "no RSA public key known for '%Y'" "; DNS search for KEY failed (%s)", id, ugh); } /* Processs the Main Mode ID Payload and the Authenticator * (Hash or Signature Payload). * If a DNS query is still needed to get the other host's public key, * the query is initiated and STF_SUSPEND is returned. * Note: parameter kc is a continuation containing the results from * the previous DNS query, or NULL indicating no query has been issued. */ static stf_status main_id_and_auth(struct msg_digest *md , bool initiator /* are we the Initiator? */ , cont_fn_t cont_fn /* continuation function */ , const struct key_continuation *kc /* current state, can be NULL */ ) { chunk_t hash = chunk_alloca(MAX_DIGEST_LEN); struct state *st = md->st; identification_t *peer; stf_status r = STF_OK; /* ID Payload in */ if (!decode_peer_id(md, &peer)) { return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } /* Hash the ID Payload. * main_mode_hash requires idpl->cur to be at end of payload * so we temporarily set if so. */ { pb_stream *idpl = &md->chain[ISAKMP_NEXT_ID]->pbs; u_int8_t *old_cur = idpl->cur; idpl->cur = idpl->roof; main_mode_hash(st, &hash, !initiator, idpl); idpl->cur = old_cur; } switch (st->st_oakley.auth) { case OAKLEY_PRESHARED_KEY: case XAUTHInitPreShared: case XAUTHRespPreShared: { pb_stream *const hash_pbs = &md->chain[ISAKMP_NEXT_HASH]->pbs; if (pbs_left(hash_pbs) != hash.len || memcmp(hash_pbs->cur, hash.ptr, hash.len) != 0) { DBG_cond_dump(DBG_CRYPT, "received HASH:" , hash_pbs->cur, pbs_left(hash_pbs)); loglog(RC_LOG_SERIOUS, "received Hash Payload does not match computed value"); /* XXX Could send notification back */ r = STF_FAIL + ISAKMP_INVALID_HASH_INFORMATION; } } break; case OAKLEY_RSA_SIG: case XAUTHInitRSA: case XAUTHRespRSA: r = check_signature(KEY_RSA, peer, st, hash, &md->chain[ISAKMP_NEXT_SIG]->pbs, #ifdef USE_KEYRR kc == NULL ? NULL : kc->ac.keys_from_dns, #endif /* USE_KEYRR */ kc == NULL ? NULL : kc->ac.gateways_from_dns ); if (r == STF_SUSPEND) { /* initiate/resume asynchronous DNS lookup for key */ struct key_continuation *nkc = malloc_thing(struct key_continuation); enum key_oppo_step step_done = kc == NULL? kos_null : kc->step; err_t ugh = NULL; /* Record that state is used by a suspended md */ passert(st->st_suspended_md == NULL); st->st_suspended_md = md; nkc->failure_ok = FALSE; nkc->md = md; switch (step_done) { case kos_null: /* first try: look for the TXT records */ nkc->step = kos_his_txt; #ifdef USE_KEYRR nkc->failure_ok = TRUE; #endif ugh = start_adns_query(peer, peer, T_TXT, cont_fn, &nkc->ac); break; #ifdef USE_KEYRR case kos_his_txt: /* second try: look for the KEY records */ nkc->step = kos_his_key; ugh = start_adns_query(peer, NULL, T_KEY, cont_fn, &nkc->ac); break; #endif /* USE_KEYRR */ default: bad_case(step_done); } if (ugh != NULL) { report_key_dns_failure(peer, ugh); st->st_suspended_md = NULL; r = STF_FAIL + ISAKMP_INVALID_KEY_INFORMATION; } } break; case OAKLEY_ECDSA_256: case OAKLEY_ECDSA_384: case OAKLEY_ECDSA_521: r = check_signature(KEY_ECDSA, peer, st, hash, &md->chain[ISAKMP_NEXT_SIG]->pbs, #ifdef USE_KEYRR NULL, #endif /* USE_KEYRR */ NULL); break; default: bad_case(st->st_oakley.auth); } if (r != STF_OK) { peer->destroy(peer); return r; } DBG(DBG_CRYPT, DBG_log("authentication succeeded")); /* * With the peer ID known, let's see if we need to switch connections. */ if (!switch_connection(md, peer, initiator)) { r = STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } peer->destroy(peer); return r; } /* This continuation is called as part of either * the main_inI3_outR3 state or main_inR3 state. * * The "tail" function is the corresponding tail * function main_inI3_outR3_tail | main_inR3_tail, * either directly when the state is started, or via * adns continuation. * * Basically, we go around in a circle: * main_in?3* -> key_continue * ^ \ * / V * adns main_in?3*_tail * ^ | * \ V * main_id_and_auth * * until such time as main_id_and_auth is able * to find authentication, or we run out of things * to try. */ static void key_continue(struct adns_continuation *cr, err_t ugh, key_tail_fn *tail) { struct key_continuation *kc = (void *)cr; struct state *st = kc->md->st; passert(cur_state == NULL); /* if st == NULL, our state has been deleted -- just clean up */ if (st != NULL) { stf_status r; passert(st->st_suspended_md == kc->md); st->st_suspended_md = NULL; /* no longer connected or suspended */ cur_state = st; if (!kc->failure_ok && ugh != NULL) { report_key_dns_failure(st->st_connection->spd.that.id, ugh); r = STF_FAIL + ISAKMP_INVALID_KEY_INFORMATION; } else { #ifdef USE_KEYRR passert(kc->step == kos_his_txt || kc->step == kos_his_key); #else passert(kc->step == kos_his_txt); #endif kc->last_ugh = ugh; /* record previous error in case we need it */ r = (*tail)(kc->md, kc); } complete_state_transition(&kc->md, r); } if (kc->md != NULL) { release_md(kc->md); } cur_state = NULL; } /* STATE_MAIN_R2: * PSK_AUTH: HDR*, IDi1, HASH_I --> HDR*, IDr1, HASH_R * DS_AUTH: HDR*, IDi1, [ CERT, ] SIG_I --> HDR*, IDr1, [ CERT, ] SIG_R * PKE_AUTH, RPKE_AUTH: HDR*, HASH_I --> HDR*, HASH_R * * Broken into parts to allow asynchronous DNS lookup. * * - main_inI3_outR3 to start * - main_inI3_outR3_tail to finish or suspend for DNS lookup * - main_inI3_outR3_continue to start main_inI3_outR3_tail again */ static key_tail_fn main_inI3_outR3_tail; /* forward */ stf_status main_inI3_outR3(struct msg_digest *md) { return main_inI3_outR3_tail(md, NULL); } static void main_inI3_outR3_continue(struct adns_continuation *cr, err_t ugh) { key_continue(cr, ugh, main_inI3_outR3_tail); } static stf_status main_inI3_outR3_tail(struct msg_digest *md , struct key_continuation *kc) { struct state *const st = md->st; u_int8_t auth_payload; pb_stream r_id_pbs; /* ID Payload; also used for hash calculation */ certpolicy_t cert_policy; cert_t *mycert; bool pubkey_auth, send_cert, requested; /* ID and HASH_I or SIG_I in * Note: this may switch the connection being used! */ { stf_status r = main_id_and_auth(md, FALSE , main_inI3_outR3_continue , kc); if (r != STF_OK) { return r; } } /* send certificate if pubkey authentication is used, we have one * and we want or are requested to send it */ cert_policy = st->st_connection->spd.this.sendcert; mycert = st->st_connection->spd.this.cert; requested = cert_policy == CERT_SEND_IF_ASKED && st->st_connection->got_certrequest; pubkey_auth = uses_pubkey_auth(st->st_oakley.auth); send_cert = pubkey_auth && mycert && mycert->cert->get_type(mycert->cert) == CERT_X509 && (cert_policy == CERT_ALWAYS_SEND || requested); /*************** build output packet HDR*;IDir;HASH/SIG_R ***************/ /* proccess_packet() would automatically generate the HDR* * payload if smc->first_out_payload is not ISAKMP_NEXT_NONE. * We don't do this because we wish there to be no partially * built output packet if we need to suspend for asynch DNS. */ /* ??? NOTE: this is almost the same as main_inR2_outI3's code */ /* HDR* out * If auth were PKE_AUTH or RPKE_AUTH, ISAKMP_NEXT_HASH would * be first payload. */ echo_hdr(md, TRUE, ISAKMP_NEXT_ID); auth_payload = pubkey_auth ? ISAKMP_NEXT_SIG : ISAKMP_NEXT_HASH; /* IDir out */ { /* id_hd should be struct isakmp_id, but struct isakmp_ipsec_id * allows build_id_payload() to work for both phases. */ struct isakmp_ipsec_id id_hd; chunk_t id_b; build_id_payload(&id_hd, &id_b, &st->st_connection->spd.this); id_hd.isaiid_np = (send_cert)? ISAKMP_NEXT_CERT : auth_payload; if (!out_struct(&id_hd, &isakmp_ipsec_identification_desc, &md->rbody, &r_id_pbs) || !out_chunk(id_b, &r_id_pbs, "my identity")) { return STF_INTERNAL_ERROR; } close_output_pbs(&r_id_pbs); } /* CERT out */ if (pubkey_auth) { DBG(DBG_CONTROL, DBG_log("our certificate policy is %N", cert_policy_names, cert_policy) ) if (mycert && mycert->cert->get_type(mycert->cert) == CERT_X509) { const char *request_text = ""; if (cert_policy == CERT_SEND_IF_ASKED) { request_text = (send_cert)? "upon request":"without request"; } plog("we have a cert %s sending it %s" , send_cert? "and are":"but are not", request_text); } else { plog("we don't have a cert"); } } if (send_cert) { bool success; chunk_t cert_encoding; pb_stream cert_pbs; struct isakmp_cert cert_hd; cert_hd.isacert_np = ISAKMP_NEXT_SIG; cert_hd.isacert_type = CERT_X509_SIGNATURE; if (!out_struct(&cert_hd, &isakmp_ipsec_certificate_desc, &md->rbody, &cert_pbs)) { return STF_INTERNAL_ERROR; } cert_encoding = mycert->cert->get_encoding(mycert->cert); success = out_chunk(cert_encoding, &cert_pbs, "CERT"); free(cert_encoding.ptr); if (!success) { return STF_INTERNAL_ERROR; } close_output_pbs(&cert_pbs); } /* HASH_R or SIG_R out */ { chunk_t hash = chunk_alloca(MAX_DIGEST_LEN); main_mode_hash(st, &hash, FALSE, &r_id_pbs); if (auth_payload == ISAKMP_NEXT_HASH) { /* HASH_R out */ if (!out_generic_raw(ISAKMP_NEXT_NONE, &isakmp_hash_desc, &md->rbody, hash.ptr, hash.len, "HASH_R")) { return STF_INTERNAL_ERROR; } } else { /* SIG_R out */ u_char sig_val[RSA_MAX_OCTETS]; signature_scheme_t scheme; size_t sig_len; scheme = oakley_to_signature_scheme(st->st_oakley.auth); sig_len = sign_hash(scheme, st->st_connection, sig_val, hash); if (sig_len == 0) { loglog(RC_LOG_SERIOUS, "unable to locate my private key for signature"); return STF_FAIL + ISAKMP_AUTHENTICATION_FAILED; } if (!out_generic_raw(ISAKMP_NEXT_NONE, &isakmp_signature_desc , &md->rbody, sig_val, sig_len, "SIG_R")) { return STF_INTERNAL_ERROR; } } } /* encrypt message, sans fixed part of header */ if (!encrypt_message(&md->rbody, st)) { return STF_INTERNAL_ERROR; /* ??? we may be partly committed */ } /* Last block of Phase 1 (R3), kept for Phase 2 IV generation */ DBG_cond_dump(DBG_CRYPT, "last encrypted block of Phase 1:" , st->st_new_iv, st->st_new_iv_len); ISAKMP_SA_established(st->st_connection, st->st_serialno); /* Save Phase 1 IV */ st->st_ph1_iv_len = st->st_new_iv_len; set_ph1_iv(st, st->st_new_iv); return STF_OK; } /* STATE_MAIN_I3: * Handle HDR*;IDir;HASH/SIG_R from responder. * * Broken into parts to allow asynchronous DNS for KEY records. * * - main_inR3 to start * - main_inR3_tail to finish or suspend for DNS lookup * - main_inR3_continue to start main_inR3_tail again */ static key_tail_fn main_inR3_tail; /* forward */ stf_status main_inR3(struct msg_digest *md) { return main_inR3_tail(md, NULL); } static void main_inR3_continue(struct adns_continuation *cr, err_t ugh) { key_continue(cr, ugh, main_inR3_tail); } static stf_status main_inR3_tail(struct msg_digest *md, struct key_continuation *kc) { struct state *const st = md->st; /* ID and HASH_R or SIG_R in * Note: this may switch the connection being used! */ { stf_status r = main_id_and_auth(md, TRUE, main_inR3_continue, kc); if (r != STF_OK) { return r; } } /**************** done input ****************/ ISAKMP_SA_established(st->st_connection, st->st_serialno); /* Save Phase 1 IV */ st->st_ph1_iv_len = st->st_new_iv_len; set_ph1_iv(st, st->st_new_iv); update_iv(st); /* finalize our Phase 1 IV */ return STF_OK; } /* Handle first message of Phase 2 -- Quick Mode. * HDR*, HASH(1), SA, Ni [, KE ] [, IDci, IDcr ] --> * HDR*, HASH(2), SA, Nr [, KE ] [, IDci, IDcr ] * (see RFC 2409 "IKE" 5.5) * Installs inbound IPsec SAs. * Although this seems early, we know enough to do so, and * this way we know that it is soon enough to catch all * packets that other side could send using this IPsec SA. * * Broken into parts to allow asynchronous DNS for TXT records: * * - quick_inI1_outR1 starts the ball rolling. * It checks and parses enough to learn the Phase 2 IDs * * - quick_inI1_outR1_tail does the rest of the job * unless DNS must be consulted. In that case, * it starts a DNS query, salts away what is needed * to continue, and suspends. Calls * + quick_inI1_outR1_start_query * + quick_inI1_outR1_process_answer * * - quick_inI1_outR1_continue will restart quick_inI1_outR1_tail * when DNS comes back with an answer. * * A big chunk of quick_inI1_outR1_tail is executed twice. * This is necessary because the set of connections * might change while we are awaiting DNS. * When first called, gateways_from_dns == NULL. If DNS is * consulted asynchronously, gateways_from_dns != NULL the second time. * Remember that our state object might disappear too! * * * If the connection is opportunistic, we must verify delegation. * * 1. Check that we are authorized to be SG for * our client. We look for the TXT record that * delegates us. We also check that the public * key (if present) matches the private key we used. * Eventually, we should probably require DNSsec * authentication for our side. * * 2. If our client TXT record did not include a * public key, check the KEY record indicated * by the identity in the TXT record. * * 3. If the peer's client is the peer itself, we * consider it authenticated. Otherwise, we check * the TXT record for the client to see that * the identity of the SG matches the peer and * that some public key (if present in the TXT) * matches. We need not check the public key if * it isn't in the TXT record. * * Since p isn't yet instantiated, we need to look * in c for description of peer. * * We cannot afford to block waiting for a DNS query. * The code here is structured as two halves: * - process the result of just completed * DNS query (if any) * - if another query is needed, initiate the next * DNS query and suspend */ enum verify_oppo_step { vos_fail, vos_start, vos_our_client, vos_our_txt, #ifdef USE_KEYRR vos_our_key, #endif /* USE_KEYRR */ vos_his_client, vos_done }; static const char *const verify_step_name[] = { "vos_fail", "vos_start", "vos_our_client", "vos_our_txt", #ifdef USE_KEYRR "vos_our_key", #endif /* USE_KEYRR */ "vos_his_client", "vos_done" }; /* hold anything we can handle of a Phase 2 ID */ struct p2id { ip_subnet net; u_int8_t proto; u_int16_t port; }; struct verify_oppo_bundle { enum verify_oppo_step step; bool failure_ok; /* if true, quick_inI1_outR1_continue will try * other things on DNS failure */ struct msg_digest *md; struct p2id my, his; unsigned int new_iv_len; /* p1st's might change */ u_char new_iv[MAX_DIGEST_LEN]; /* int whackfd; */ /* not needed because we are Responder */ }; struct verify_oppo_continuation { struct adns_continuation ac; /* common prefix */ struct verify_oppo_bundle b; }; static stf_status quick_inI1_outR1_tail(struct verify_oppo_bundle *b , struct adns_continuation *ac); stf_status quick_inI1_outR1(struct msg_digest *md) { const struct state *const p1st = md->st; connection_t *c = p1st->st_connection; struct payload_digest *const id_pd = md->chain[ISAKMP_NEXT_ID]; struct verify_oppo_bundle b; /* HASH(1) in */ CHECK_QUICK_HASH(md , quick_mode_hash12(hash_val, hash_pbs->roof, md->message_pbs.roof , p1st, &md->hdr.isa_msgid, FALSE) , "HASH(1)", "Quick I1"); /* [ IDci, IDcr ] in * We do this now (probably out of physical order) because * we wish to select the correct connection before we consult * it for policy. */ if (id_pd != NULL) { /* ??? we are assuming IPSEC_DOI */ /* IDci (initiator is peer) */ if (!decode_net_id(&id_pd->payload.ipsec_id, &id_pd->pbs , &b.his.net, "peer client")) { return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } /* Hack for MS 818043 NAT-T Update */ if (id_pd->payload.ipsec_id.isaiid_idtype == ID_FQDN) { happy(addrtosubnet(&c->spd.that.host_addr, &b.his.net)); } /* End Hack for MS 818043 NAT-T Update */ b.his.proto = id_pd->payload.ipsec_id.isaiid_protoid; b.his.port = id_pd->payload.ipsec_id.isaiid_port; b.his.net.addr.u.v4.sin_port = htons(b.his.port); /* IDcr (we are responder) */ if (!decode_net_id(&id_pd->next->payload.ipsec_id, &id_pd->next->pbs , &b.my.net, "our client")) { return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } b.my.proto = id_pd->next->payload.ipsec_id.isaiid_protoid; b.my.port = id_pd->next->payload.ipsec_id.isaiid_port; b.my.net.addr.u.v4.sin_port = htons(b.my.port); } else { /* implicit IDci and IDcr: peer and self */ if (!sameaddrtype(&c->spd.this.host_addr, &c->spd.that.host_addr)) { return STF_FAIL; } happy(addrtosubnet(&c->spd.this.host_addr, &b.my.net)); happy(addrtosubnet(&c->spd.that.host_addr, &b.his.net)); b.his.proto = b.my.proto = 0; b.his.port = b.my.port = 0; } b.step = vos_start; b.md = md; b.new_iv_len = p1st->st_new_iv_len; memcpy(b.new_iv, p1st->st_new_iv, p1st->st_new_iv_len); return quick_inI1_outR1_tail(&b, NULL); } static void report_verify_failure(struct verify_oppo_bundle *b, err_t ugh) { struct state *st = b->md->st; char fgwb[ADDRTOT_BUF] , cb[ADDRTOT_BUF]; ip_address client; err_t which = NULL; switch (b->step) { case vos_our_client: case vos_our_txt: #ifdef USE_KEYRR case vos_our_key: #endif /* USE_KEYRR */ which = "our"; networkof(&b->my.net, &client); break; case vos_his_client: which = "his"; networkof(&b->his.net, &client); break; case vos_start: case vos_done: case vos_fail: default: bad_case(b->step); } addrtot(&st->st_connection->spd.that.host_addr, 0, fgwb, sizeof(fgwb)); addrtot(&client, 0, cb, sizeof(cb)); loglog(RC_OPPOFAILURE , "gateway %s wants connection with %s as %s client, but DNS fails to confirm delegation: %s" , fgwb, cb, which, ugh); } static void quick_inI1_outR1_continue(struct adns_continuation *cr, err_t ugh) { stf_status r; struct verify_oppo_continuation *vc = (void *)cr; struct verify_oppo_bundle *b = &vc->b; struct state *st = b->md->st; passert(cur_state == NULL); /* if st == NULL, our state has been deleted -- just clean up */ if (st != NULL) { passert(st->st_suspended_md == b->md); st->st_suspended_md = NULL; /* no longer connected or suspended */ cur_state = st; if (!b->failure_ok && ugh != NULL) { report_verify_failure(b, ugh); r = STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } else { r = quick_inI1_outR1_tail(b, cr); } complete_state_transition(&b->md, r); } if (b->md != NULL) { release_md(b->md); } cur_state = NULL; } static stf_status quick_inI1_outR1_start_query(struct verify_oppo_bundle *b, enum verify_oppo_step next_step) { struct msg_digest *md = b->md; struct state *p1st = md->st; connection_t *c = p1st->st_connection; struct verify_oppo_continuation *vc = malloc_thing(struct verify_oppo_continuation); identification_t *id; /* subject of query */ identification_t *our_id; /* needed for myid playing */ identification_t *our_id_space; /* ephemeral: no need for unshare_id_content */ ip_address client; err_t ugh = NULL; /* Record that state is used by a suspended md */ b->step = next_step; /* not just vc->b.step */ vc->b = *b; passert(p1st->st_suspended_md == NULL); p1st->st_suspended_md = b->md; DBG(DBG_CONTROL, { char ours[SUBNETTOT_BUF]; char his[SUBNETTOT_BUF]; subnettot(&c->spd.this.client, 0, ours, sizeof(ours)); subnettot(&c->spd.that.client, 0, his, sizeof(his)); DBG_log("responding with DNS query - from %s to %s new state: %s" , ours, his, verify_step_name[b->step]); }); /* Resolve %myid in a cheesy way. * We have to do the resolution because start_adns_query * et al have insufficient information to do so. * If %myid is already known, we'll use that value * (XXX this may be a mistake: it could be stale). * If %myid is unknown, we should check to see if * there are credentials for the IP address or the FQDN. * Instead, we'll just assume the IP address since we are * acting as the responder and only the IP address would * have gotten it to us. * We don't even try to do this for the other side: * %myid makes no sense for the other side (but it is syntactically * legal). */ our_id = resolve_myid(c->spd.this.id); if (our_id->get_type(our_id) == ID_ANY) { our_id_space = identification_create_from_sockaddr((sockaddr_t*)&c->spd.this.host_addr); our_id = our_id_space; } switch (next_step) { case vos_our_client: networkof(&b->my.net, &client); id = identification_create_from_sockaddr((sockaddr_t*)&client); vc->b.failure_ok = b->failure_ok = FALSE; ugh = start_adns_query(id , our_id , T_TXT , quick_inI1_outR1_continue , &vc->ac); break; case vos_our_txt: vc->b.failure_ok = b->failure_ok = TRUE; ugh = start_adns_query(our_id , our_id /* self as SG */ , T_TXT , quick_inI1_outR1_continue , &vc->ac); break; #ifdef USE_KEYRR case vos_our_key: vc->b.failure_ok = b->failure_ok = FALSE; ugh = start_adns_query(our_id , NULL , T_KEY , quick_inI1_outR1_continue , &vc->ac); break; #endif case vos_his_client: networkof(&b->his.net, &client); id = identification_create_from_sockaddr((sockaddr_t*)&client); vc->b.failure_ok = b->failure_ok = FALSE; ugh = start_adns_query(id , c->spd.that.id , T_TXT , quick_inI1_outR1_continue , &vc->ac); break; default: bad_case(next_step); } if (ugh != NULL) { /* note: we'd like to use vc->b but vc has been freed * so we have to use b. This is why we plunked next_state * into b, not just vc->b. */ report_verify_failure(b, ugh); p1st->st_suspended_md = NULL; return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } else { return STF_SUSPEND; } } static enum verify_oppo_step quick_inI1_outR1_process_answer( struct verify_oppo_bundle *b, struct adns_continuation *ac, struct state *p1st) { connection_t *c = p1st->st_connection; enum verify_oppo_step next_step = vos_our_client; err_t ugh = NULL; DBG(DBG_CONTROL, { char ours[SUBNETTOT_BUF]; char his[SUBNETTOT_BUF]; subnettot(&c->spd.this.client, 0, ours, sizeof(ours)); subnettot(&c->spd.that.client, 0, his, sizeof(his)); DBG_log("responding on demand from %s to %s state: %s" , ours, his, verify_step_name[b->step]); }); /* process just completed DNS query (if any) */ switch (b->step) { case vos_start: /* no query to digest */ next_step = vos_our_client; break; case vos_our_client: next_step = vos_his_client; { private_key_t *private = get_private_key(c); struct gw_info *gwp; if (private == NULL) { ugh = "we don't know our own key"; break; } ugh = "our client does not delegate us as its Security Gateway"; for (gwp = ac->gateways_from_dns; gwp != NULL; gwp = gwp->next) { ugh = "our client delegates us as its Security Gateway but with the wrong public key"; /* If there is no key in the TXT record, * we count it as a win, but we will have * to separately fetch and check the KEY record. * If there is a key from the TXT record, * we count it as a win if we match the key. */ if (!gwp->gw_key_present) { next_step = vos_our_txt; ugh = NULL; /* good! */ break; } else if (private->belongs_to(private, gwp->key->public_key)) { ugh = NULL; /* good! */ break; } } } break; case vos_our_txt: next_step = vos_his_client; { private_key_t *private = get_private_key(c); if (private == NULL) { ugh = "we don't know our own key"; break; } { struct gw_info *gwp; for (gwp = ac->gateways_from_dns; gwp != NULL; gwp = gwp->next) { #ifdef USE_KEYRR /* not an error yet, because we have to check KEY RR as well */ ugh = NULL; #else ugh = "our client delegation depends on our " RRNAME " record, but it has the wrong public key"; #endif if (gwp->gw_key_present && private->belongs_to(private, gwp->key->public_key)) { ugh = NULL; /* good! */ break; } #ifdef USE_KEYRR next_step = vos_our_key; #endif } } } break; #ifdef USE_KEYRR case vos_our_key: next_step = vos_his_client; { private_key_t *private = get_private_key(c); if (private == NULL) { ugh = "we don't know our own key"; break; } { pubkey_list_t *kp; ugh = "our client delegation depends on our missing " RRNAME " record"; for (kp = ac->keys_from_dns; kp != NULL; kp = kp->next) { ugh = "our client delegation depends on our " RRNAME " record, but it has the wrong public key"; if (private->belongs_to(private, kp->key->public_key)) { /* do this only once a day */ if (!logged_txt_warning) { loglog(RC_LOG_SERIOUS, "found KEY RR but not TXT RR. See http://www.freeswan.org/err/txt-change.html."); logged_txt_warning = TRUE; } ugh = NULL; /* good! */ break; } } } } break; #endif /* USE_KEYRR */ case vos_his_client: next_step = vos_done; { public_key_t *pub_key; struct gw_info *gwp; /* check that the public key that authenticated * the ISAKMP SA (p1st) will do for this gateway. */ pub_key = p1st->st_peer_pubkey->public_key; ugh = "peer's client does not delegate to peer"; for (gwp = ac->gateways_from_dns; gwp != NULL; gwp = gwp->next) { ugh = "peer and its client disagree about public key"; /* If there is a key from the TXT record, * we count it as a win if we match the key. * If there was no key, we claim a match since * it implies fetching a KEY from the same * place we must have gotten it. */ if (!gwp->gw_key_present || pub_key->equals(pub_key, gwp->key->public_key)) { ugh = NULL; /* good! */ break; } } } break; default: bad_case(b->step); } if (ugh != NULL) { report_verify_failure(b, ugh); next_step = vos_fail; } return next_step; } static stf_status quick_inI1_outR1_tail(struct verify_oppo_bundle *b, struct adns_continuation *ac) { struct msg_digest *md = b->md; struct state *const p1st = md->st; connection_t *c = p1st->st_connection; struct payload_digest *const id_pd = md->chain[ISAKMP_NEXT_ID]; ip_subnet *our_net = &b->my.net , *his_net = &b->his.net; u_char /* set by START_HASH_PAYLOAD: */ *r_hashval, /* where in reply to jam hash value */ *r_hash_start; /* from where to start hashing */ /* Now that we have identities of client subnets, we must look for * a suitable connection (our current one only matches for hosts). */ { connection_t *p = find_client_connection(c , our_net, his_net, b->my.proto, b->my.port, b->his.proto, b->his.port); if (p == NULL) { /* This message occurs in very puzzling circumstances * so we must add as much information and beauty as we can. */ struct end me = c->spd.this, he = c->spd.that; char buf[2*SUBNETTOT_BUF + 2*ADDRTOT_BUF + 2*BUF_LEN + 2*ADDRTOT_BUF + 12]; /* + 12 for separating */ size_t l; me.client = *our_net; me.has_client = !subnetisaddr(our_net, &me.host_addr); me.protocol = b->my.proto; me.port = b->my.port; he.client = *his_net; he.has_client = !subnetisaddr(his_net, &he.host_addr); he.protocol = b->his.proto; he.port = b->his.port; l = format_end(buf, sizeof(buf), &me, NULL, TRUE, LEMPTY); l += snprintf(buf + l, sizeof(buf) - l, "..."); (void)format_end(buf + l, sizeof(buf) - l, &he, NULL, FALSE, LEMPTY); plog("cannot respond to IPsec SA request" " because no connection is known for %s" , buf); return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } else if (p != c) { /* We've got a better connection: it can support the * specified clients. But it may need instantiation. */ if (p->kind == CK_TEMPLATE) { /* Yup, it needs instantiation. How much? * Is it a Road Warrior connection (simple) * or is it an Opportunistic connection (needing gw validation)? */ if (p->policy & POLICY_OPPO) { /* Opportunistic case: delegation must be verified. * Here be dragons. */ enum verify_oppo_step next_step; ip_address our_client, his_client; passert(subnetishost(our_net) && subnetishost(his_net)); networkof(our_net, &our_client); networkof(his_net, &his_client); next_step = quick_inI1_outR1_process_answer(b, ac, p1st); if (next_step == vos_fail) { return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } /* short circuit: if peer's client is self, * accept that we've verified delegation in Phase 1 */ if (next_step == vos_his_client && sameaddr(&c->spd.that.host_addr, &his_client)) { next_step = vos_done; } /* the second chunk: initiate the next DNS query (if any) */ DBG(DBG_CONTROL, { char ours[SUBNETTOT_BUF]; char his[SUBNETTOT_BUF]; subnettot(&c->spd.this.client, 0, ours, sizeof(ours)); subnettot(&c->spd.that.client, 0, his, sizeof(his)); DBG_log("responding on demand from %s to %s new state: %s" , ours, his, verify_step_name[next_step]); }); /* start next DNS query and suspend (if necessary) */ if (next_step != vos_done) { return quick_inI1_outR1_start_query(b, next_step); } /* Instantiate inbound Opportunistic connection, * carrying over authenticated peer ID * and filling in a few more details. * We used to include gateways_from_dns, but that * seems pointless at this stage of negotiation. * We should record DNS sec use, if any -- belongs in * state during perhaps. */ p = oppo_instantiate(p, &c->spd.that.host_addr, c->spd.that.id , NULL, &our_client, &his_client); } else { /* Plain Road Warrior: * instantiate, carrying over authenticated peer ID */ p = rw_instantiate(p, &c->spd.that.host_addr, md->sender_port , his_net, c->spd.that.id); } } #ifdef DEBUG /* temporarily bump up cur_debugging to get "using..." message * printed if we'd want it with new connection. */ { lset_t old_cur_debugging = cur_debugging; cur_debugging |= p->extra_debugging; DBG(DBG_CONTROL, DBG_log("using connection \"%s\"", p->name)); cur_debugging = old_cur_debugging; } #endif c = p; } /* fill in the client's true ip address/subnet */ if (p->spd.that.has_client_wildcard) { p->spd.that.client = *his_net; p->spd.that.has_client_wildcard = FALSE; } else if (is_virtual_connection(c)) { c->spd.that.client = *his_net; c->spd.that.virt = NULL; if (subnetishost(his_net) && addrinsubnet(&c->spd.that.host_addr, his_net)) { c->spd.that.has_client = FALSE; } } /* fill in the client's true port */ if (p->spd.that.has_port_wildcard) { int port = htons(b->his.port); setportof(port, &p->spd.that.host_addr); setportof(port, &p->spd.that.client.addr); p->spd.that.port = b->his.port; p->spd.that.has_port_wildcard = FALSE; } } /* now that we are sure of our connection, create our new state */ { struct state *const st = duplicate_state(p1st); /* first: fill in missing bits of our new state object * note: we don't copy over st_peer_pubkey, the public key * that authenticated the ISAKMP SA. We only need it in this * routine, so we can "reach back" to p1st to get it. */ if (st->st_connection != c) { connection_t *t = st->st_connection; st->st_connection = c; set_cur_connection(c); connection_discard(t); } st->st_try = 0; /* not our job to try again from start */ st->st_msgid = md->hdr.isa_msgid; st->st_new_iv_len = b->new_iv_len; memcpy(st->st_new_iv, b->new_iv, b->new_iv_len); set_cur_state(st); /* (caller will reset) */ md->st = st; /* feed back new state */ st->st_peeruserprotoid = b->his.proto; st->st_peeruserport = b->his.port; st->st_myuserprotoid = b->my.proto; st->st_myuserport = b->my.port; insert_state(st); /* needs cookies, connection, and msgid */ /* copy the connection's * IPSEC policy into our state. The ISAKMP policy is water under * the bridge, I think. It will reflect the ISAKMP SA that we * are using. */ st->st_policy = (p1st->st_policy & POLICY_ISAKMP_MASK) | (c->policy & ~POLICY_ISAKMP_MASK); if (p1st->nat_traversal & NAT_T_DETECTED) { st->nat_traversal = p1st->nat_traversal; nat_traversal_change_port_lookup(md, md->st); } else { st->nat_traversal = 0; } if ((st->nat_traversal & NAT_T_DETECTED) && (st->nat_traversal & NAT_T_WITH_NATOA)) { nat_traversal_natoa_lookup(md); } /* Start the output packet. * * proccess_packet() would automatically generate the HDR* * payload if smc->first_out_payload is not ISAKMP_NEXT_NONE. * We don't do this because we wish there to be no partially * built output packet if we need to suspend for asynch DNS. * * We build the reply packet as we parse the message since * the parse_ipsec_sa_body emits the reply SA */ /* HDR* out */ echo_hdr(md, TRUE, ISAKMP_NEXT_HASH); /* HASH(2) out -- first pass */ START_HASH_PAYLOAD(md->rbody, ISAKMP_NEXT_SA); /* process SA (in and out) */ { struct payload_digest *const sapd = md->chain[ISAKMP_NEXT_SA]; pb_stream r_sa_pbs; struct isakmp_sa sa = sapd->payload.sa; /* sa header is unchanged -- except for np */ sa.isasa_np = ISAKMP_NEXT_NONCE; if (!out_struct(&sa, &isakmp_sa_desc, &md->rbody, &r_sa_pbs)) { return STF_INTERNAL_ERROR; } /* parse and accept body */ st->st_pfs_group = &unset_group; RETURN_STF_FAILURE(parse_ipsec_sa_body(&sapd->pbs , &sapd->payload.sa, &r_sa_pbs, FALSE, st)); } passert(st->st_pfs_group != &unset_group); if ((st->st_policy & POLICY_PFS) && st->st_pfs_group == NULL) { loglog(RC_LOG_SERIOUS, "we require PFS but Quick I1 SA specifies no GROUP_DESCRIPTION"); return STF_FAIL + ISAKMP_NO_PROPOSAL_CHOSEN; } /* Ni in */ RETURN_STF_FAILURE(accept_nonce(md, &st->st_ni, "Ni")); /* [ KE ] in (for PFS) */ RETURN_STF_FAILURE(accept_PFS_KE(md, &st->st_gi, "Gi", "Quick Mode I1")); plog("responding to Quick Mode"); /**** finish reply packet: Nr [, KE ] [, IDci, IDcr ] ****/ /* Nr out */ if (!build_and_ship_nonce(&st->st_nr, &md->rbody , st->st_pfs_group != NULL? ISAKMP_NEXT_KE : id_pd != NULL? ISAKMP_NEXT_ID : ISAKMP_NEXT_NONE , "Nr")) { return STF_INTERNAL_ERROR; } /* [ KE ] out (for PFS) */ if (st->st_pfs_group != NULL) { if (!build_and_ship_KE(st, &st->st_gr, st->st_pfs_group , &md->rbody, id_pd != NULL? ISAKMP_NEXT_ID : ISAKMP_NEXT_NONE)) { return STF_INTERNAL_ERROR; } /* MPZ-Operations might be done after sending the packet... */ compute_dh_shared(st, st->st_gi); } /* [ IDci, IDcr ] out */ if (id_pd != NULL) { struct isakmp_ipsec_id *p = (void *)md->rbody.cur; /* UGH! */ if (!out_raw(id_pd->pbs.start, pbs_room(&id_pd->pbs), &md->rbody, "IDci")) { return STF_INTERNAL_ERROR; } p->isaiid_np = ISAKMP_NEXT_ID; p = (void *)md->rbody.cur; /* UGH! */ if (!out_raw(id_pd->next->pbs.start, pbs_room(&id_pd->next->pbs), &md->rbody, "IDcr")) { return STF_INTERNAL_ERROR; } p->isaiid_np = ISAKMP_NEXT_NONE; } if ((st->nat_traversal & NAT_T_WITH_NATOA) && (st->nat_traversal & LELEM(NAT_TRAVERSAL_NAT_BHND_ME)) && (st->st_esp.attrs.encapsulation == ENCAPSULATION_MODE_TRANSPORT)) { /** Send NAT-OA if our address is NATed and if we use Transport Mode */ if (!nat_traversal_add_natoa(ISAKMP_NEXT_NONE, &md->rbody, md->st)) { return STF_INTERNAL_ERROR; } } if ((st->nat_traversal & NAT_T_DETECTED) && (st->st_esp.attrs.encapsulation == ENCAPSULATION_MODE_TRANSPORT) && (c->spd.that.has_client)) { /** Remove client **/ addrtosubnet(&c->spd.that.host_addr, &c->spd.that.client); c->spd.that.has_client = FALSE; } /* Compute reply HASH(2) and insert in output */ (void)quick_mode_hash12(r_hashval, r_hash_start, md->rbody.cur , st, &st->st_msgid, TRUE); /* Derive new keying material */ compute_keymats(st); /* Tell the kernel to establish the new inbound SA * (unless the commit bit is set -- which we don't support). * We do this before any state updating so that * failure won't look like success. */ if (!install_inbound_ipsec_sa(st)) { return STF_INTERNAL_ERROR; /* ??? we may be partly committed */ } /* encrypt message, except for fixed part of header */ if (!encrypt_message(&md->rbody, st)) { return STF_INTERNAL_ERROR; /* ??? we may be partly committed */ } return STF_OK; } } /* * Initialize RFC 3706 Dead Peer Detection */ static void dpd_init(struct state *st) { struct state *p1st = find_state(st->st_icookie, st->st_rcookie , &st->st_connection->spd.that.host_addr, 0); if (p1st == NULL) { loglog(RC_LOG_SERIOUS, "could not find phase 1 state for DPD"); } else if (p1st->st_dpd) { plog("Dead Peer Detection (RFC 3706) enabled"); /* randomize the first DPD event */ event_schedule(EVENT_DPD , (0.5 + rand()/(RAND_MAX + 1.E0)) * st->st_connection->dpd_delay , st); } } /* Handle (the single) message from Responder in Quick Mode. * HDR*, HASH(2), SA, Nr [, KE ] [, IDci, IDcr ] --> * HDR*, HASH(3) * (see RFC 2409 "IKE" 5.5) * Installs inbound and outbound IPsec SAs, routing, etc. */ stf_status quick_inR1_outI2(struct msg_digest *md) { struct state *const st = md->st; const connection_t *c = st->st_connection; /* HASH(2) in */ CHECK_QUICK_HASH(md , quick_mode_hash12(hash_val, hash_pbs->roof, md->message_pbs.roof , st, &st->st_msgid, TRUE) , "HASH(2)", "Quick R1"); /* SA in */ { struct payload_digest *const sa_pd = md->chain[ISAKMP_NEXT_SA]; RETURN_STF_FAILURE(parse_ipsec_sa_body(&sa_pd->pbs , &sa_pd->payload.sa, NULL, TRUE, st)); } /* Nr in */ RETURN_STF_FAILURE(accept_nonce(md, &st->st_nr, "Nr")); /* [ KE ] in (for PFS) */ RETURN_STF_FAILURE(accept_PFS_KE(md, &st->st_gr, "Gr", "Quick Mode R1")); if (st->st_pfs_group != NULL) { compute_dh_shared(st, st->st_gr); } /* [ IDci, IDcr ] in; these must match what we sent */ { struct payload_digest *const id_pd = md->chain[ISAKMP_NEXT_ID]; if (id_pd != NULL) { /* ??? we are assuming IPSEC_DOI */ /* IDci (we are initiator) */ if (!check_net_id(&id_pd->payload.ipsec_id, &id_pd->pbs , &st->st_myuserprotoid, &st->st_myuserport , &st->st_connection->spd.this.client , "our client")) { return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } /* IDcr (responder is peer) */ if (!check_net_id(&id_pd->next->payload.ipsec_id, &id_pd->next->pbs , &st->st_peeruserprotoid, &st->st_peeruserport , &st->st_connection->spd.that.client , "peer client")) { return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } } else { /* no IDci, IDcr: we must check that the defaults match our proposal */ if (!subnetisaddr(&c->spd.this.client, &c->spd.this.host_addr) || !subnetisaddr(&c->spd.that.client, &c->spd.that.host_addr)) { loglog(RC_LOG_SERIOUS, "IDci, IDcr payloads missing in message" " but default does not match proposal"); return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } } } /* check the peer's group attributes */ { identification_t *peer_ca = NULL; ietf_attributes_t *peer_attributes = NULL; bool match; get_peer_ca_and_groups(st->st_connection, &peer_ca, &peer_attributes); match = match_group_membership(peer_attributes, st->st_connection->name, st->st_connection->spd.that.groups); DESTROY_IF(peer_attributes); if (!match) { ietf_attributes_t *groups = st->st_connection->spd.that.groups; loglog(RC_LOG_SERIOUS, "peer with attributes '%s' is not a member of the groups '%s'", peer_attributes->get_string(peer_attributes), groups->get_string(groups)); return STF_FAIL + ISAKMP_INVALID_ID_INFORMATION; } } if ((st->nat_traversal & NAT_T_DETECTED) && (st->nat_traversal & NAT_T_WITH_NATOA)) { nat_traversal_natoa_lookup(md); } /* ??? We used to copy the accepted proposal into the state, but it was * never used. From sa_pd->pbs.start, length pbs_room(&sa_pd->pbs). */ /**************** build reply packet HDR*, HASH(3) ****************/ /* HDR* out done */ /* HASH(3) out -- since this is the only content, no passes needed */ { u_char /* set by START_HASH_PAYLOAD: */ *r_hashval, /* where in reply to jam hash value */ *r_hash_start; /* start of what is to be hashed */ START_HASH_PAYLOAD(md->rbody, ISAKMP_NEXT_NONE); (void)quick_mode_hash3(r_hashval, st); } /* Derive new keying material */ compute_keymats(st); /* Tell the kernel to establish the inbound, outbound, and routing part * of the new SA (unless the commit bit is set -- which we don't support). * We do this before any state updating so that * failure won't look like success. */ if (!install_ipsec_sa(st, TRUE)) { return STF_INTERNAL_ERROR; } /* encrypt message, except for fixed part of header */ if (!encrypt_message(&md->rbody, st)) { return STF_INTERNAL_ERROR; /* ??? we may be partly committed */ } DBG(DBG_CONTROLMORE, DBG_log("inR1_outI2: instance %s[%ld], setting newest_ipsec_sa to #%ld (was #%ld) (spd.eroute=#%ld)" , st->st_connection->name , st->st_connection->instance_serial , st->st_serialno , st->st_connection->newest_ipsec_sa , st->st_connection->spd.eroute_owner) ) st->st_connection->newest_ipsec_sa = st->st_serialno; /* note (presumed) success */ if (c->gw_info != NULL) { c->gw_info->key->last_worked_time = now(); } /* If we want DPD on this connection then initialize it */ if (st->st_connection->dpd_action != DPD_ACTION_NONE) { dpd_init(st); } return STF_OK; } /* Handle last message of Quick Mode. * HDR*, HASH(3) -> done * (see RFC 2409 "IKE" 5.5) * Installs outbound IPsec SAs, routing, etc. */ stf_status quick_inI2(struct msg_digest *md) { struct state *const st = md->st; /* HASH(3) in */ CHECK_QUICK_HASH(md, quick_mode_hash3(hash_val, st) , "HASH(3)", "Quick I2"); /* Tell the kernel to establish the outbound and routing part of the new SA * (the previous state established inbound) * (unless the commit bit is set -- which we don't support). * We do this before any state updating so that * failure won't look like success. */ if (!install_ipsec_sa(st, FALSE)) { return STF_INTERNAL_ERROR; } DBG(DBG_CONTROLMORE, DBG_log("inI2: instance %s[%ld], setting newest_ipsec_sa to #%ld (was #%ld) (spd.eroute=#%ld)" , st->st_connection->name , st->st_connection->instance_serial , st->st_serialno , st->st_connection->newest_ipsec_sa , st->st_connection->spd.eroute_owner) ) st->st_connection->newest_ipsec_sa = st->st_serialno; update_iv(st); /* not actually used, but tidy */ /* note (presumed) success */ { struct gw_info *gw = st->st_connection->gw_info; if (gw != NULL) { gw->key->last_worked_time = now(); } } /* If we want DPD on this connection then initialize it */ if (st->st_connection->dpd_action != DPD_ACTION_NONE) { dpd_init(st); } return STF_OK; } static stf_status send_isakmp_notification(struct state *st, u_int16_t type, const void *data, size_t len) { msgid_t msgid; pb_stream reply; pb_stream rbody; u_char *r_hashval, /* where in reply to jam hash value */ *r_hash_start; /* start of what is to be hashed */ msgid = generate_msgid(st); init_pbs(&reply, reply_buffer, sizeof(reply_buffer), "ISAKMP notify"); /* HDR* */ { struct isakmp_hdr hdr; hdr.isa_version = ISAKMP_MAJOR_VERSION << ISA_MAJ_SHIFT | ISAKMP_MINOR_VERSION; hdr.isa_np = ISAKMP_NEXT_HASH; hdr.isa_xchg = ISAKMP_XCHG_INFO; hdr.isa_msgid = msgid; hdr.isa_flags = ISAKMP_FLAG_ENCRYPTION; memcpy(hdr.isa_icookie, st->st_icookie, COOKIE_SIZE); memcpy(hdr.isa_rcookie, st->st_rcookie, COOKIE_SIZE); if (!out_struct(&hdr, &isakmp_hdr_desc, &reply, &rbody)) { impossible(); } } /* HASH -- create and note space to be filled later */ START_HASH_PAYLOAD(rbody, ISAKMP_NEXT_N); /* NOTIFY */ { pb_stream notify_pbs; struct isakmp_notification isan; isan.isan_np = ISAKMP_NEXT_NONE; isan.isan_doi = ISAKMP_DOI_IPSEC; isan.isan_protoid = PROTO_ISAKMP; isan.isan_spisize = COOKIE_SIZE * 2; isan.isan_type = type; if (!out_struct(&isan, &isakmp_notification_desc, &rbody, ¬ify_pbs)) { return STF_INTERNAL_ERROR; } if (!out_raw(st->st_icookie, COOKIE_SIZE, ¬ify_pbs, "notify icookie")) { return STF_INTERNAL_ERROR; } if (!out_raw(st->st_rcookie, COOKIE_SIZE, ¬ify_pbs, "notify rcookie")) { return STF_INTERNAL_ERROR; } if (data != NULL && len > 0) { if (!out_raw(data, len, ¬ify_pbs, "notify data")) { return STF_INTERNAL_ERROR; } } close_output_pbs(¬ify_pbs); } { /* finish computing HASH */ chunk_t msgid_chunk = chunk_from_thing(msgid); chunk_t msg_chunk = { r_hash_start, rbody.cur-r_hash_start }; pseudo_random_function_t prf_alg; prf_t *prf; prf_alg = oakley_to_prf(st->st_oakley.hash); prf = lib->crypto->create_prf(lib->crypto, prf_alg); prf->set_key(prf, st->st_skeyid_a); prf->get_bytes(prf, msgid_chunk, NULL); prf->get_bytes(prf, msg_chunk, r_hashval); DBG(DBG_CRYPT, DBG_log("HASH computed:"); DBG_dump("", r_hashval, prf->get_block_size(prf)); ) prf->destroy(prf); } /* Encrypt message (preserve st_iv and st_new_iv) */ { u_char old_iv[MAX_DIGEST_LEN]; u_char new_iv[MAX_DIGEST_LEN]; u_int old_iv_len = st->st_iv_len; u_int new_iv_len = st->st_new_iv_len; if (old_iv_len > MAX_DIGEST_LEN || new_iv_len > MAX_DIGEST_LEN) return STF_INTERNAL_ERROR; memcpy(old_iv, st->st_iv, old_iv_len); memcpy(new_iv, st->st_new_iv, new_iv_len); init_phase2_iv(st, &msgid); if (!encrypt_message(&rbody, st)) { return STF_INTERNAL_ERROR; } /* restore preserved st_iv and st_new_iv */ memcpy(st->st_iv, old_iv, old_iv_len); memcpy(st->st_new_iv, new_iv, new_iv_len); st->st_iv_len = old_iv_len; st->st_new_iv_len = new_iv_len; } /* Send packet (preserve st_tpacket) */ { chunk_t saved_tpacket = st->st_tpacket; st->st_tpacket = chunk_create(reply.start, pbs_offset(&reply)); send_packet(st, "ISAKMP notify"); st->st_tpacket = saved_tpacket; } return STF_IGNORE; } /* * DPD Out Initiator */ void dpd_outI(struct state *p2st) { struct state *st; u_int32_t seqno; time_t tm; time_t idle_time; time_t delay = p2st->st_connection->dpd_delay; time_t timeout = p2st->st_connection->dpd_timeout; /* find the newest related Phase 1 state */ st = find_phase1_state(p2st->st_connection, ISAKMP_SA_ESTABLISHED_STATES); if (st == NULL) { loglog(RC_LOG_SERIOUS, "DPD: Could not find newest phase 1 state"); return; } /* If no DPD, then get out of here */ if (!st->st_dpd) { return; } /* schedule the next periodic DPD event */ event_schedule(EVENT_DPD, delay, p2st); /* Current time */ tm = now(); /* Make sure we really need to invoke DPD */ if (!was_eroute_idle(p2st, delay, &idle_time)) { DBG(DBG_CONTROL, DBG_log("recent eroute activity %u seconds ago, " "no need to send DPD notification" , (int)idle_time) ) st->st_last_dpd = tm; delete_dpd_event(st); return; } /* If an R_U_THERE has been sent or received recently, or if a * companion Phase 2 SA has shown eroute activity, * then we don't need to invoke DPD. */ if (tm < st->st_last_dpd + delay) { DBG(DBG_CONTROL, DBG_log("recent DPD activity %u seconds ago, " "no need to send DPD notification" , (int)(tm - st->st_last_dpd)) ) return; } if (!IS_ISAKMP_SA_ESTABLISHED(st->st_state)) return; if (!st->st_dpd_seqno) { rng_t *rng; /* Get a non-zero random value that has room to grow */ rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK); rng->get_bytes(rng, sizeof(st->st_dpd_seqno), (u_char *)&st->st_dpd_seqno); rng->destroy(rng); st->st_dpd_seqno &= 0x7fff; st->st_dpd_seqno++; } seqno = htonl(st->st_dpd_seqno); if (send_isakmp_notification(st, R_U_THERE, &seqno, sizeof(seqno)) != STF_IGNORE) { loglog(RC_LOG_SERIOUS, "DPD: Could not send R_U_THERE"); return; } DBG(DBG_CONTROL, DBG_log("sent DPD notification R_U_THERE with seqno = %u", st->st_dpd_seqno) ) st->st_dpd_expectseqno = st->st_dpd_seqno++; st->st_last_dpd = tm; /* Only schedule a new timeout if there isn't one currently, * or if it would be sooner than the current timeout. */ if (st->st_dpd_event == NULL || st->st_dpd_event->ev_time > tm + timeout) { delete_dpd_event(st); event_schedule(EVENT_DPD_TIMEOUT, timeout, st); } } /* * DPD in Initiator, out Responder */ stf_status dpd_inI_outR(struct state *st, struct isakmp_notification *const n, pb_stream *pbs) { time_t tm = now(); u_int32_t seqno; if (st == NULL || !IS_ISAKMP_SA_ESTABLISHED(st->st_state)) { loglog(RC_LOG_SERIOUS, "DPD: Received R_U_THERE for unestablished ISAKMP SA"); return STF_IGNORE; } if (n->isan_spisize != COOKIE_SIZE * 2 || pbs_left(pbs) < COOKIE_SIZE * 2) { loglog(RC_LOG_SERIOUS, "DPD: R_U_THERE has invalid SPI length (%d)", n->isan_spisize); return STF_FAIL + ISAKMP_PAYLOAD_MALFORMED; } if (memcmp(pbs->cur, st->st_icookie, COOKIE_SIZE) != 0) { #ifdef APPLY_CRISCO /* Ignore it, cisco sends odd icookies */ #else loglog(RC_LOG_SERIOUS, "DPD: R_U_THERE has invalid icookie (broken Cisco?)"); return STF_FAIL + ISAKMP_INVALID_COOKIE; #endif } pbs->cur += COOKIE_SIZE; if (memcmp(pbs->cur, st->st_rcookie, COOKIE_SIZE) != 0) { loglog(RC_LOG_SERIOUS, "DPD: R_U_THERE has invalid rcookie (broken Cisco?)"); return STF_FAIL + ISAKMP_INVALID_COOKIE; } pbs->cur += COOKIE_SIZE; if (pbs_left(pbs) != sizeof(seqno)) { loglog(RC_LOG_SERIOUS, "DPD: R_U_THERE has invalid data length (%d)" , (int) pbs_left(pbs)); return STF_FAIL + ISAKMP_PAYLOAD_MALFORMED; } seqno = ntohl(*(u_int32_t *)pbs->cur); DBG(DBG_CONTROL, DBG_log("received DPD notification R_U_THERE with seqno = %u", seqno) ) if (st->st_dpd_peerseqno && seqno <= st->st_dpd_peerseqno) { loglog(RC_LOG_SERIOUS, "DPD: Received old or duplicate R_U_THERE"); return STF_IGNORE; } st->st_dpd_peerseqno = seqno; delete_dpd_event(st); if (send_isakmp_notification(st, R_U_THERE_ACK, pbs->cur, pbs_left(pbs)) != STF_IGNORE) { loglog(RC_LOG_SERIOUS, "DPD Info: could not send R_U_THERE_ACK"); return STF_IGNORE; } DBG(DBG_CONTROL, DBG_log("sent DPD notification R_U_THERE_ACK with seqno = %u", seqno) ) st->st_last_dpd = tm; return STF_IGNORE; } /* * DPD out Responder */ stf_status dpd_inR(struct state *st, struct isakmp_notification *const n, pb_stream *pbs) { u_int32_t seqno; if (st == NULL || !IS_ISAKMP_SA_ESTABLISHED(st->st_state)) { loglog(RC_LOG_SERIOUS , "DPD: Received R_U_THERE_ACK for unestablished ISAKMP SA"); return STF_FAIL; } if (n->isan_spisize != COOKIE_SIZE * 2 || pbs_left(pbs) < COOKIE_SIZE * 2) { loglog(RC_LOG_SERIOUS , "DPD: R_U_THERE_ACK has invalid SPI length (%d)" , n->isan_spisize); return STF_FAIL + ISAKMP_PAYLOAD_MALFORMED; } if (memcmp(pbs->cur, st->st_icookie, COOKIE_SIZE) != 0) { #ifdef APPLY_CRISCO /* Ignore it, cisco sends odd icookies */ #else loglog(RC_LOG_SERIOUS, "DPD: R_U_THERE_ACK has invalid icookie"); return STF_FAIL + ISAKMP_INVALID_COOKIE; #endif } pbs->cur += COOKIE_SIZE; if (memcmp(pbs->cur, st->st_rcookie, COOKIE_SIZE) != 0) { #ifdef APPLY_CRISCO /* Ignore it, cisco sends odd icookies */ #else loglog(RC_LOG_SERIOUS, "DPD: R_U_THERE_ACK has invalid rcookie"); return STF_FAIL + ISAKMP_INVALID_COOKIE; #endif } pbs->cur += COOKIE_SIZE; if (pbs_left(pbs) != sizeof(seqno)) { loglog(RC_LOG_SERIOUS , " DPD: R_U_THERE_ACK has invalid data length (%d)" , (int) pbs_left(pbs)); return STF_FAIL + ISAKMP_PAYLOAD_MALFORMED; } seqno = ntohl(*(u_int32_t *)pbs->cur); DBG(DBG_CONTROL, DBG_log("received DPD notification R_U_THERE_ACK with seqno = %u" , seqno) ) if (!st->st_dpd_expectseqno && seqno != st->st_dpd_expectseqno) { loglog(RC_LOG_SERIOUS , "DPD: R_U_THERE_ACK has unexpected sequence number %u (expected %u)" , seqno, st->st_dpd_expectseqno); return STF_FAIL + ISAKMP_PAYLOAD_MALFORMED; } st->st_dpd_expectseqno = 0; delete_dpd_event(st); return STF_IGNORE; } /* * DPD Timeout Function * * This function is called when a timeout DPD_EVENT occurs. We set clear/trap * both the SA and the eroutes, depending on what the connection definition * tells us (either 'hold' or 'clear') */ void dpd_timeout(struct state *st) { struct state *newest_phase1_st; connection_t *c = st->st_connection; int action = st->st_connection->dpd_action; char cname[BUF_LEN]; passert(action == DPD_ACTION_HOLD || action == DPD_ACTION_CLEAR || DPD_ACTION_RESTART); /* is there a newer phase1_state? */ newest_phase1_st = find_phase1_state(c, ISAKMP_SA_ESTABLISHED_STATES); if (newest_phase1_st != NULL && newest_phase1_st != st) { plog("DPD: Phase1 state #%ld has been superseded by #%ld" " - timeout ignored" , st->st_serialno, newest_phase1_st->st_serialno); return; } loglog(RC_LOG_SERIOUS, "DPD: No response from peer - declaring peer dead"); /* delete the state, which is probably in phase 2 */ set_cur_connection(c); plog("DPD: Terminating all SAs using this connection"); delete_states_by_connection(c, TRUE); reset_cur_connection(); switch (action) { case DPD_ACTION_HOLD: /* dpdaction=hold - Wipe the SA's but %trap the eroute so we don't * leak traffic. Also, being in %trap means new packets will * force an initiation of the conn again. */ loglog(RC_LOG_SERIOUS, "DPD: Putting connection \"%s\" into %%trap", c->name); if (c->kind == CK_INSTANCE) { delete_connection(c, TRUE); } break; case DPD_ACTION_CLEAR: /* dpdaction=clear - Wipe the SA & eroute - everything */ loglog(RC_LOG_SERIOUS, "DPD: Clearing connection \"%s\"", c->name); unroute_connection(c); if (c->kind == CK_INSTANCE) { delete_connection(c, TRUE); } break; case DPD_ACTION_RESTART: /* dpdaction=restart - Restart connection, * except if roadwarrior connection */ loglog(RC_LOG_SERIOUS, "DPD: Restarting connection \"%s\"", c->name); unroute_connection(c); /* caching the connection name before deletion */ strncpy(cname, c->name, BUF_LEN); if (c->kind == CK_INSTANCE) { delete_connection(c, TRUE); } initiate_connection(cname, NULL_FD); break; default: loglog(RC_LOG_SERIOUS, "DPD: unknown action"); } }