/* $OpenBSD: ipsec.c,v 1.32 2000/12/12 01:45:31 niklas Exp $ */ /* $EOM: ipsec.c,v 1.143 2000/12/11 23:57:42 niklas Exp $ */ /* * Copyright (c) 1998, 1999, 2000 Niklas Hallqvist. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Ericsson Radio Systems. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * This code was written under funding by Ericsson Radio Systems. */ #include #include #include #include #include #include #include #include "sysdep.h" #include "attribute.h" #include "conf.h" #include "constants.h" #include "crypto.h" #include "dh.h" #include "doi.h" #include "exchange.h" #include "hash.h" #include "ike_aggressive.h" #include "ike_auth.h" #include "ike_main_mode.h" #include "ike_quick_mode.h" #include "ipsec.h" #include "ipsec_doi.h" #include "isakmp.h" #include "log.h" #include "math_group.h" #include "message.h" #include "prf.h" #include "sa.h" #include "timer.h" #include "transport.h" #include "util.h" /* Backwards compatibility. */ #ifndef NI_MAXHOST #define NI_MAXHOST 1025 #endif /* The replay window size used for all IPSec protocols if not overridden. */ #define DEFAULT_REPLAY_WINDOW 16 struct ipsec_decode_arg { struct message *msg; struct sa *sa; struct proto *proto; }; /* These variables hold the contacted peers ADT state. */ struct contact { struct sockaddr *addr; socklen_t len; } *contacts = 0; int contact_cnt = 0, contact_limit = 0; static int addr_cmp (const void *, const void *); static int ipsec_add_contact (struct message *msg); static int ipsec_contacted (struct message *msg); #ifdef USE_DEBUG static int ipsec_debug_attribute (u_int16_t, u_int8_t *, u_int16_t, void *); #endif static void ipsec_delete_spi (struct sa *, struct proto *, int); static u_int16_t *ipsec_exchange_script (u_int8_t); static void ipsec_finalize_exchange (struct message *); static void ipsec_free_exchange_data (void *); static void ipsec_free_proto_data (void *); static void ipsec_free_sa_data (void *); static struct keystate *ipsec_get_keystate (struct message *); static u_int8_t *ipsec_get_spi (size_t *, u_int8_t, struct message *); static int ipsec_handle_leftover_payload (struct message *, u_int8_t, struct payload *); static int ipsec_informational_post_hook (struct message *); static int ipsec_informational_pre_hook (struct message *); static int ipsec_initiator (struct message *); static void ipsec_proto_init (struct proto *, char *); static int ipsec_responder (struct message *); static void ipsec_setup_situation (u_int8_t *); static void ipsec_set_network (u_int8_t *, u_int8_t *, struct ipsec_sa *); static size_t ipsec_situation_size (void); static u_int8_t ipsec_spi_size (u_int8_t); static int ipsec_validate_attribute (u_int16_t, u_int8_t *, u_int16_t, void *); static int ipsec_validate_exchange (u_int8_t); static int ipsec_validate_id_information (u_int8_t, u_int8_t *, u_int8_t *, size_t, struct exchange *); static int ipsec_validate_key_information (u_int8_t *, size_t); static int ipsec_validate_notification (u_int16_t); static int ipsec_validate_proto (u_int8_t); static int ipsec_validate_situation (u_int8_t *, size_t *); static int ipsec_validate_transform_id (u_int8_t, u_int8_t); static struct doi ipsec_doi = { { 0 }, IPSEC_DOI_IPSEC, sizeof (struct ipsec_exch), sizeof (struct ipsec_sa), sizeof (struct ipsec_proto), #ifdef USE_DEBUG ipsec_debug_attribute, #endif ipsec_delete_spi, ipsec_exchange_script, ipsec_finalize_exchange, ipsec_free_exchange_data, ipsec_free_proto_data, ipsec_free_sa_data, ipsec_get_keystate, ipsec_get_spi, ipsec_handle_leftover_payload, ipsec_informational_post_hook, ipsec_informational_pre_hook, ipsec_is_attribute_incompatible, ipsec_proto_init, ipsec_setup_situation, ipsec_situation_size, ipsec_spi_size, ipsec_validate_attribute, ipsec_validate_exchange, ipsec_validate_id_information, ipsec_validate_key_information, ipsec_validate_notification, ipsec_validate_proto, ipsec_validate_situation, ipsec_validate_transform_id, ipsec_initiator, ipsec_responder, #ifdef USE_DEBUG ipsec_decode_ids #endif }; int16_t script_quick_mode[] = { ISAKMP_PAYLOAD_HASH, /* Initiator -> responder. */ ISAKMP_PAYLOAD_SA, ISAKMP_PAYLOAD_NONCE, EXCHANGE_SCRIPT_SWITCH, ISAKMP_PAYLOAD_HASH, /* Responder -> initiator. */ ISAKMP_PAYLOAD_SA, ISAKMP_PAYLOAD_NONCE, EXCHANGE_SCRIPT_SWITCH, ISAKMP_PAYLOAD_HASH, /* Initiator -> responder. */ EXCHANGE_SCRIPT_END }; int16_t script_new_group_mode[] = { ISAKMP_PAYLOAD_HASH, /* Initiator -> responder. */ ISAKMP_PAYLOAD_SA, EXCHANGE_SCRIPT_SWITCH, ISAKMP_PAYLOAD_HASH, /* Responder -> initiator. */ ISAKMP_PAYLOAD_SA, EXCHANGE_SCRIPT_END }; struct dst_spi_proto_arg { in_addr_t dst; u_int32_t spi; u_int8_t proto; }; /* * Check if SA matches what we are asking for through V_ARG. It has to * be a finished phase 2 SA. */ static int ipsec_sa_check (struct sa *sa, void *v_arg) { struct dst_spi_proto_arg *arg = v_arg; struct proto *proto; struct sockaddr *dst, *src; int dstlen, srclen; int incoming; if (sa->phase != 2 || !(sa->flags & SA_FLAG_READY)) return 0; sa->transport->vtbl->get_dst (sa->transport, &dst, &dstlen); if (((struct sockaddr_in *)dst)->sin_addr.s_addr == arg->dst) incoming = 0; else { sa->transport->vtbl->get_src (sa->transport, &src, &srclen); if (((struct sockaddr_in *)src)->sin_addr.s_addr == arg->dst) incoming = 1; else return 0; } for (proto = TAILQ_FIRST (&sa->protos); proto; proto = TAILQ_NEXT (proto, link)) if (proto->proto == arg->proto && memcmp (proto->spi[incoming], &arg->spi, sizeof arg->spi) == 0) return 1; return 0; } /* Find an SA with a "name" of DST, SPI & PROTO. */ struct sa * ipsec_sa_lookup (in_addr_t dst, u_int32_t spi, u_int8_t proto) { struct dst_spi_proto_arg arg = { dst, spi, proto }; return sa_find (ipsec_sa_check, &arg); } /* * Check if SA matches the flow of another SA in V_ARG. It has to * be a finished non-replaced phase 2 SA. * XXX At some point other selectors will matter here too. */ static int ipsec_sa_check_flow (struct sa *sa, void *v_arg) { struct sa *sa2 = v_arg; struct ipsec_sa *isa = sa->data, *isa2 = sa2->data; if (sa == sa2 || sa->phase != 2 || (sa->flags & (SA_FLAG_READY | SA_FLAG_REPLACED)) != SA_FLAG_READY) return 0; return isa->src_net == isa2->src_net && isa->src_mask == isa2->src_mask && isa->dst_net == isa2->dst_net && isa->dst_mask == isa2->dst_mask && isa->tproto == isa2->tproto && isa->sport == isa2->sport && isa->dport == isa2->dport; } /* * Do IPSec DOI specific finalizations task for the exchange where MSG was * the final message. */ static void ipsec_finalize_exchange (struct message *msg) { struct sa *isakmp_sa = msg->isakmp_sa; struct ipsec_sa *isa; struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; struct sa *sa = 0, *old_sa; struct proto *proto, *last_proto = 0; switch (exchange->phase) { case 1: switch (exchange->type) { case ISAKMP_EXCH_ID_PROT: case ISAKMP_EXCH_AGGRESSIVE: isa = isakmp_sa->data; isa->hash = ie->hash->type; isa->prf_type = ie->prf_type; isa->skeyid_len = ie->skeyid_len; isa->skeyid_d = ie->skeyid_d; isa->skeyid_a = ie->skeyid_a; /* Prevents early free of SKEYID_*. */ ie->skeyid_a = ie->skeyid_d = 0; /* If a lifetime was negotiated setup the expiration timers. */ if (isakmp_sa->seconds) sa_setup_expirations (isakmp_sa); break; } break; case 2: switch (exchange->type) { case IKE_EXCH_QUICK_MODE: /* * Tell the application(s) about the SPIs and key material. */ for (sa = TAILQ_FIRST (&exchange->sa_list); sa; sa = TAILQ_NEXT (sa, next)) { for (proto = TAILQ_FIRST (&sa->protos), last_proto = 0; proto; proto = TAILQ_NEXT (proto, link)) { if (sysdep_ipsec_set_spi (sa, proto, 0) || (last_proto && sysdep_ipsec_group_spis (sa, last_proto, proto, 0)) || sysdep_ipsec_set_spi (sa, proto, 1) || (last_proto && sysdep_ipsec_group_spis (sa, last_proto, proto, 1))) /* XXX Tear down this exchange. */ return; last_proto = proto; } isa = sa->data; if (exchange->initiator) /* Initiator is source, responder is destination. */ ipsec_set_network (ie->id_ci, ie->id_cr, isa); else /* Responder is source, initiator is destination. */ ipsec_set_network (ie->id_cr, ie->id_ci, isa); LOG_DBG ((LOG_EXCHANGE, 50, "ipsec_finalize_exchange: " "src %x %x dst %x %x tproto %u sport %u dport %u", ntohl (isa->src_net), ntohl (isa->src_mask), ntohl (isa->dst_net), ntohl (isa->dst_mask), ntohs (isa->tproto), isa->sport, ntohs (isa->dport))); /* * If this is not an SA acquired by the kernel, it needs * to have a SPD entry (a.k.a. flow) set up. */ if (!(sa->flags & SA_FLAG_ONDEMAND) && sysdep_ipsec_enable_sa (sa, isakmp_sa)) /* XXX Tear down this exchange. */ return; /* Mark elder SAs with the same flow information as replaced. */ while ((old_sa = sa_find (ipsec_sa_check_flow, sa)) != 0) sa_mark_replaced (old_sa); } break; } } } /* Set the client addresses in ISA from SRC_ID and DST_ID. */ static void ipsec_set_network (u_int8_t *src_id, u_int8_t *dst_id, struct ipsec_sa *isa) { int id; /* Set source address. */ id = GET_ISAKMP_ID_TYPE (src_id); switch (id) { case IPSEC_ID_IPV4_ADDR: memcpy (&isa->src_net, src_id + ISAKMP_ID_DATA_OFF, sizeof isa->src_net); isa->src_mask = htonl (0xffffffff); memcpy (&isa->tproto, src_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PROTO_OFF, IPSEC_ID_PROTO_LEN); memcpy (&isa->sport, src_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PORT_OFF, IPSEC_ID_PORT_LEN); break; case IPSEC_ID_IPV4_ADDR_SUBNET: memcpy (&isa->src_net, src_id + ISAKMP_ID_DATA_OFF, sizeof isa->src_net); memcpy (&isa->src_mask, src_id + ISAKMP_ID_DATA_OFF + sizeof isa->src_net, sizeof isa->src_mask); memcpy (&isa->tproto, src_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PROTO_OFF, IPSEC_ID_PROTO_LEN); memcpy (&isa->sport, src_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PORT_OFF, IPSEC_ID_PORT_LEN); break; } /* Set destination address. */ id = GET_ISAKMP_ID_TYPE (dst_id); switch (id) { case IPSEC_ID_IPV4_ADDR: memcpy (&isa->dst_net, dst_id + ISAKMP_ID_DATA_OFF, sizeof isa->dst_net); isa->dst_mask = htonl (0xffffffff); memcpy (&isa->tproto, dst_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PROTO_OFF, IPSEC_ID_PROTO_LEN); memcpy (&isa->dport, dst_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PORT_OFF, IPSEC_ID_PORT_LEN); break; case IPSEC_ID_IPV4_ADDR_SUBNET: memcpy (&isa->dst_net, dst_id + ISAKMP_ID_DATA_OFF, sizeof isa->dst_net); memcpy (&isa->dst_mask, dst_id + ISAKMP_ID_DATA_OFF + sizeof isa->dst_net, sizeof isa->dst_mask); memcpy (&isa->tproto, dst_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PROTO_OFF, IPSEC_ID_PROTO_LEN); memcpy (&isa->dport, dst_id + ISAKMP_ID_DOI_DATA_OFF + IPSEC_ID_PORT_OFF, IPSEC_ID_PORT_LEN); break; } } /* Free the DOI-specific exchange data pointed to by VIE. */ static void ipsec_free_exchange_data (void *vie) { struct ipsec_exch *ie = vie; if (ie->sa_i_b) free (ie->sa_i_b); if (ie->id_ci) free (ie->id_ci); if (ie->id_cr) free (ie->id_cr); if (ie->g_xi) free (ie->g_xi); if (ie->g_xr) free (ie->g_xr); if (ie->g_xy) free (ie->g_xy); if (ie->skeyid) free (ie->skeyid); if (ie->skeyid_d) free (ie->skeyid_d); if (ie->skeyid_a) free (ie->skeyid_a); if (ie->skeyid_e) free (ie->skeyid_e); if (ie->hash_i) free (ie->hash_i); if (ie->hash_r) free (ie->hash_r); if (ie->group) group_free (ie->group); } /* Free the DOI-specific SA data pointed to by VISA. */ static void ipsec_free_sa_data (void *visa) { struct ipsec_sa *isa = visa; if (isa->skeyid_a) free (isa->skeyid_a); if (isa->skeyid_d) free (isa->skeyid_d); } /* Free the DOI-specific protocol data of an SA pointed to by VIPROTO. */ static void ipsec_free_proto_data (void *viproto) { struct ipsec_proto *iproto = viproto; int i; for (i = 0; i < 2; i++) if (iproto->keymat[i]) free (iproto->keymat[i]); } /* Return exchange script based on TYPE. */ static u_int16_t * ipsec_exchange_script (u_int8_t type) { switch (type) { case IKE_EXCH_QUICK_MODE: return script_quick_mode; case IKE_EXCH_NEW_GROUP_MODE: return script_new_group_mode; } return 0; } /* Initialize this DOI, requires doi_init to already have been called. */ void ipsec_init () { doi_register (&ipsec_doi); } /* Given a message MSG, return a suitable IV (or rather keystate). */ static struct keystate * ipsec_get_keystate (struct message *msg) { struct keystate *ks; struct hash *hash; /* If we have already have an IV, use it. */ if (msg->exchange && msg->exchange->keystate) { ks = malloc (sizeof *ks); if (!ks) { log_error ("ipsec_get_keystate: malloc (%d) failed", sizeof *ks); return 0; } memcpy (ks, msg->exchange->keystate, sizeof *ks); return ks; } /* * For phase 2 when no SA yet is setup we need to hash the IV used by * the ISAKMP SA concatenated with the message ID, and use that as an * IV for further cryptographic operations. */ if (!msg->isakmp_sa->keystate) { log_print ("ipsec_get_keystate: no keystate in ISAKMP SA %p", msg->isakmp_sa); return 0; } ks = crypto_clone_keystate (msg->isakmp_sa->keystate); if (!ks) return 0; hash = hash_get (((struct ipsec_sa *)msg->isakmp_sa->data)->hash); hash->Init (hash->ctx); LOG_DBG_BUF ((LOG_CRYPTO, 80, "ipsec_get_keystate: final phase 1 IV", ks->riv, ks->xf->blocksize)); hash->Update (hash->ctx, ks->riv, ks->xf->blocksize); LOG_DBG_BUF ((LOG_CRYPTO, 80, "ipsec_get_keystate: message ID", ((u_int8_t *)msg->iov[0].iov_base) + ISAKMP_HDR_MESSAGE_ID_OFF, ISAKMP_HDR_MESSAGE_ID_LEN)); hash->Update (hash->ctx, ((u_int8_t *)msg->iov[0].iov_base) + ISAKMP_HDR_MESSAGE_ID_OFF, ISAKMP_HDR_MESSAGE_ID_LEN); hash->Final (hash->digest, hash->ctx); crypto_init_iv (ks, hash->digest, ks->xf->blocksize); LOG_DBG_BUF ((LOG_CRYPTO, 80, "ipsec_get_keystate: phase 2 IV", hash->digest, ks->xf->blocksize)); return ks; } static void ipsec_setup_situation (u_int8_t *buf) { SET_IPSEC_SIT_SIT (buf + ISAKMP_SA_SIT_OFF, IPSEC_SIT_IDENTITY_ONLY); } static size_t ipsec_situation_size (void) { return IPSEC_SIT_SIT_LEN; } static u_int8_t ipsec_spi_size (u_int8_t proto) { return IPSEC_SPI_SIZE; } static int ipsec_validate_attribute (u_int16_t type, u_int8_t *value, u_int16_t len, void *vmsg) { struct message *msg = vmsg; if ((msg->exchange->phase == 1 && (type < IKE_ATTR_ENCRYPTION_ALGORITHM || type > IKE_ATTR_GROUP_ORDER)) || (msg->exchange->phase == 2 && (type < IPSEC_ATTR_SA_LIFE_TYPE || type > IPSEC_ATTR_COMPRESS_PRIVATE_ALGORITHM))) return -1; return 0; } static int ipsec_validate_exchange (u_int8_t exch) { return exch != IKE_EXCH_QUICK_MODE && exch != IKE_EXCH_NEW_GROUP_MODE; } static int ipsec_validate_id_information (u_int8_t type, u_int8_t *extra, u_int8_t *buf, size_t sz, struct exchange *exchange) { u_int8_t proto = GET_IPSEC_ID_PROTO (extra); u_int16_t port = GET_IPSEC_ID_PORT (extra); LOG_DBG ((LOG_MESSAGE, 0, "ipsec_validate_id_information: proto %d port %d type %d", proto, port, type)); if (type < IPSEC_ID_IPV4_ADDR || type > IPSEC_ID_KEY_ID) return -1; switch (type) { case IPSEC_ID_IPV4_ADDR: LOG_DBG_BUF ((LOG_MESSAGE, 40, "ipsec_validate_id_information: IPv4", buf, 4)); break; case IPSEC_ID_IPV4_ADDR_SUBNET: LOG_DBG_BUF ((LOG_MESSAGE, 40, "ipsec_validate_id_information: IPv4 network/netmask", buf, 8)); break; default: break; } if (exchange->phase == 1 && (proto != IPPROTO_UDP || port != UDP_DEFAULT_PORT) && (proto != 0 || port != 0)) { /* XXX SSH's ISAKMP tester fails this test (proto 17 - port 0). */ #ifdef notyet return -1; #else log_print ("ipsec_validate_id_information: " "dubious ID information accepted"); #endif } /* XXX More checks? */ return 0; } static int ipsec_validate_key_information (u_int8_t *buf, size_t sz) { /* XXX Not implemented yet. */ return 0; } static int ipsec_validate_notification (u_int16_t type) { return type < IPSEC_NOTIFY_RESPONDER_LIFETIME || type > IPSEC_NOTIFY_INITIAL_CONTACT ? -1 : 0; } static int ipsec_validate_proto (u_int8_t proto) { return proto < IPSEC_PROTO_IPSEC_AH || proto > IPSEC_PROTO_IPCOMP ? -1 : 0; } static int ipsec_validate_situation (u_int8_t *buf, size_t *sz) { int sit = GET_IPSEC_SIT_SIT (buf); int off; if (sit & (IPSEC_SIT_SECRECY | IPSEC_SIT_INTEGRITY)) { /* * XXX All the roundups below, round up to 32 bit boundaries given * that the situation field is aligned. This is not necessarily so, * but I interpret the drafts as this is like this they want it. */ off = ROUNDUP_32 (GET_IPSEC_SIT_SECRECY_LENGTH (buf)); off += ROUNDUP_32 (GET_IPSEC_SIT_SECRECY_CAT_LENGTH (buf + off)); off += ROUNDUP_32 (GET_IPSEC_SIT_INTEGRITY_LENGTH (buf + off)); off += ROUNDUP_32 (GET_IPSEC_SIT_INTEGRITY_CAT_LENGTH (buf + off)); *sz = off + IPSEC_SIT_SZ; } else *sz = IPSEC_SIT_SIT_LEN; /* Currently only "identity only" situations are supported. */ #ifdef notdef return sit & ~(IPSEC_SIT_IDENTITY_ONLY | IPSEC_SIT_SECRECY | IPSEC_SIT_INTEGRITY); #else return sit & ~IPSEC_SIT_IDENTITY_ONLY; #endif return 1; return 0; } static int ipsec_validate_transform_id (u_int8_t proto, u_int8_t transform_id) { switch (proto) { /* * As no unexpected protocols can occur, we just tie the default case * to the first case, in orer to silence a GCC warning. */ default: case ISAKMP_PROTO_ISAKMP: return transform_id != IPSEC_TRANSFORM_KEY_IKE; case IPSEC_PROTO_IPSEC_AH: return transform_id < IPSEC_AH_MD5 || transform_id > IPSEC_AH_DES ? -1 : 0; case IPSEC_PROTO_IPSEC_ESP: return transform_id < IPSEC_ESP_DES_IV64 || transform_id > IPSEC_ESP_AES ? -1 : 0; case IPSEC_PROTO_IPCOMP: return transform_id < IPSEC_IPCOMP_OUI || transform_id > IPSEC_IPCOMP_V42BIS ? -1 : 0; } } static int ipsec_initiator (struct message *msg) { struct exchange *exchange = msg->exchange; int (**script) (struct message *msg) = 0; /* Check that the SA is coherent with the IKE rules. */ if ((exchange->phase == 1 && exchange->type != ISAKMP_EXCH_ID_PROT && exchange->type != ISAKMP_EXCH_AGGRESSIVE && exchange->type != ISAKMP_EXCH_INFO) || (exchange->phase == 2 && exchange->type != IKE_EXCH_QUICK_MODE && exchange->type != ISAKMP_EXCH_INFO)) { log_print ("ipsec_initiator: unsupported exchange type %d in phase %d", exchange->type, exchange->phase); return -1; } switch (exchange->type) { case ISAKMP_EXCH_ID_PROT: script = ike_main_mode_initiator; break; #ifdef USE_AGGRESSIVE case ISAKMP_EXCH_AGGRESSIVE: script = ike_aggressive_initiator; break; #endif case ISAKMP_EXCH_INFO: return message_send_info (msg); case IKE_EXCH_QUICK_MODE: script = ike_quick_mode_initiator; break; default: log_print ("ipsec_initiator: unsupported exchange type %d", exchange->type); return -1; } /* Run the script code for this step. */ if (script) return script[exchange->step] (msg); return 0; } static int ipsec_responder (struct message *msg) { struct exchange *exchange = msg->exchange; int (**script) (struct message *msg) = 0; struct payload *p; /* Check that a new exchange is coherent with the IKE rules. */ if (exchange->step == 0 && ((exchange->phase == 1 && exchange->type != ISAKMP_EXCH_ID_PROT && exchange->type != ISAKMP_EXCH_AGGRESSIVE && exchange->type != ISAKMP_EXCH_INFO) || (exchange->phase == 2 && exchange->type == ISAKMP_EXCH_ID_PROT))) { message_drop (msg, ISAKMP_NOTIFY_UNSUPPORTED_EXCHANGE_TYPE, 0, 1, 0); return -1; } LOG_DBG ((LOG_MISC, 30, "ipsec_responder: phase %d exchange %d step %d", exchange->phase, exchange->type, exchange->step)); switch (exchange->type) { case ISAKMP_EXCH_ID_PROT: script = ike_main_mode_responder; break; #ifdef USE_AGGRESSIVE case ISAKMP_EXCH_AGGRESSIVE: script = ike_aggressive_responder; break; #endif case ISAKMP_EXCH_INFO: for (p = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_NOTIFY]); p; p = TAILQ_NEXT (p, link)) { LOG_DBG ((LOG_EXCHANGE, 10, "ipsec_responder: got NOTIFY of type %s", constant_lookup (isakmp_notify_cst, GET_ISAKMP_NOTIFY_MSG_TYPE (p->p)))); p->flags |= PL_MARK; } /* * If any DELETEs are in here, let the logic of leftover payloads deal * with them. */ return 0; case IKE_EXCH_QUICK_MODE: script = ike_quick_mode_responder; break; default: message_drop (msg, ISAKMP_NOTIFY_UNSUPPORTED_EXCHANGE_TYPE, 0, 1, 0); return -1; } /* Run the script code for this step. */ if (script) return script[exchange->step] (msg); /* * XXX So far we don't accept any proposals for exchanges we don't support. */ if (TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_SA])) { message_drop (msg, ISAKMP_NOTIFY_NO_PROPOSAL_CHOSEN, 0, 1, 0); return -1; } return 0; } static enum hashes from_ike_hash (u_int16_t hash) { switch (hash) { case IKE_HASH_MD5: return HASH_MD5; case IKE_HASH_SHA: return HASH_SHA1; } return -1; } static enum transform from_ike_crypto (u_int16_t crypto) { /* Coincidentally this is the null operation :-) */ return crypto; } /* * Find out whether the attribute of type TYPE with a LEN length value * pointed to by VALUE is incompatible with what we can handle. * VMSG is a pointer to the current message. */ int ipsec_is_attribute_incompatible (u_int16_t type, u_int8_t *value, u_int16_t len, void *vmsg) { struct message *msg = vmsg; if (msg->exchange->phase == 1) { switch (type) { case IKE_ATTR_ENCRYPTION_ALGORITHM: return !crypto_get (from_ike_crypto (decode_16 (value))); case IKE_ATTR_HASH_ALGORITHM: return !hash_get (from_ike_hash (decode_16 (value))); case IKE_ATTR_AUTHENTICATION_METHOD: return !ike_auth_get (decode_16 (value)); case IKE_ATTR_GROUP_DESCRIPTION: return decode_16 (value) < IKE_GROUP_DESC_MODP_768 || decode_16 (value) > IKE_GROUP_DESC_MODP_1536; case IKE_ATTR_GROUP_TYPE: return 1; case IKE_ATTR_GROUP_PRIME: return 1; case IKE_ATTR_GROUP_GENERATOR_1: return 1; case IKE_ATTR_GROUP_GENERATOR_2: return 1; case IKE_ATTR_GROUP_CURVE_A: return 1; case IKE_ATTR_GROUP_CURVE_B: return 1; case IKE_ATTR_LIFE_TYPE: return decode_16 (value) < IKE_DURATION_SECONDS || decode_16 (value) > IKE_DURATION_KILOBYTES; case IKE_ATTR_LIFE_DURATION: return len != 2 && len != 4; case IKE_ATTR_PRF: return 1; case IKE_ATTR_KEY_LENGTH: /* * Our crypto routines only allows key-lengths which are multiples * of an octet. */ return decode_16 (value) % 8 != 0; case IKE_ATTR_FIELD_SIZE: return 1; case IKE_ATTR_GROUP_ORDER: return 1; } } else { switch (type) { case IPSEC_ATTR_SA_LIFE_TYPE: return decode_16 (value) < IPSEC_DURATION_SECONDS || decode_16 (value) > IPSEC_DURATION_KILOBYTES; case IPSEC_ATTR_SA_LIFE_DURATION: return len != 2 && len != 4; case IPSEC_ATTR_GROUP_DESCRIPTION: return decode_16 (value) < IKE_GROUP_DESC_MODP_768 || decode_16 (value) > IKE_GROUP_DESC_MODP_1536; case IPSEC_ATTR_ENCAPSULATION_MODE: return decode_16 (value) < IPSEC_ENCAP_TUNNEL || decode_16 (value) > IPSEC_ENCAP_TRANSPORT; case IPSEC_ATTR_AUTHENTICATION_ALGORITHM: return decode_16 (value) < IPSEC_AUTH_HMAC_MD5 || decode_16 (value) > IPSEC_AUTH_KPDK; case IPSEC_ATTR_KEY_LENGTH: /* XXX Blowfish needs '0'. Others appear to disregard this attr? */ return 0; case IPSEC_ATTR_KEY_ROUNDS: return 1; case IPSEC_ATTR_COMPRESS_DICTIONARY_SIZE: return 1; case IPSEC_ATTR_COMPRESS_PRIVATE_ALGORITHM: return 1; } } /* XXX Silence gcc. */ return 1; } #ifdef USE_DEBUG /* * Log the attribute of TYPE with a LEN length value pointed to by VALUE * in human-readable form. VMSG is a pointer to the current message. */ int ipsec_debug_attribute (u_int16_t type, u_int8_t *value, u_int16_t len, void *vmsg) { struct message *msg = vmsg; char val[20]; /* XXX Transient solution. */ if (len == 2) sprintf (val, "%d", decode_16 (value)); else if (len == 4) sprintf (val, "%d", decode_32 (value)); else sprintf (val, "unrepresentable"); LOG_DBG ((LOG_MESSAGE, 50, "Attribute %s value %s", constant_name (msg->exchange->phase == 1 ? ike_attr_cst : ipsec_attr_cst, type), val)); return 0; } #endif /* * Decode the attribute of type TYPE with a LEN length value pointed to by * VALUE. VIDA is a pointer to a context structure where we can find the * current message, SA and protocol. */ int ipsec_decode_attribute (u_int16_t type, u_int8_t *value, u_int16_t len, void *vida) { struct ipsec_decode_arg *ida = vida; struct message *msg = ida->msg; struct sa *sa = ida->sa; struct ipsec_sa *isa = sa->data; struct proto *proto = ida->proto; struct ipsec_proto *iproto = proto->data; struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; static int lifetype = 0; if (exchange->phase == 1) { switch (type) { case IKE_ATTR_ENCRYPTION_ALGORITHM: /* XXX Errors possible? */ exchange->crypto = crypto_get (from_ike_crypto (decode_16 (value))); break; case IKE_ATTR_HASH_ALGORITHM: /* XXX Errors possible? */ ie->hash = hash_get (from_ike_hash (decode_16 (value))); break; case IKE_ATTR_AUTHENTICATION_METHOD: /* XXX Errors possible? */ ie->ike_auth = ike_auth_get (decode_16 (value)); break; case IKE_ATTR_GROUP_DESCRIPTION: isa->group_desc = decode_16 (value); break; case IKE_ATTR_GROUP_TYPE: break; case IKE_ATTR_GROUP_PRIME: break; case IKE_ATTR_GROUP_GENERATOR_1: break; case IKE_ATTR_GROUP_GENERATOR_2: break; case IKE_ATTR_GROUP_CURVE_A: break; case IKE_ATTR_GROUP_CURVE_B: break; case IKE_ATTR_LIFE_TYPE: lifetype = decode_16 (value); return 0; case IKE_ATTR_LIFE_DURATION: switch (lifetype) { case IKE_DURATION_SECONDS: switch (len) { case 2: sa->seconds = decode_16 (value); break; case 4: sa->seconds = decode_32 (value); break; default: /* XXX Log. */ } break; case IKE_DURATION_KILOBYTES: switch (len) { case 2: sa->kilobytes = decode_16 (value); break; case 4: sa->kilobytes = decode_32 (value); break; default: /* XXX Log. */ } break; default: /* XXX Log! */ } break; case IKE_ATTR_PRF: break; case IKE_ATTR_KEY_LENGTH: exchange->key_length = decode_16 (value) / 8; break; case IKE_ATTR_FIELD_SIZE: break; case IKE_ATTR_GROUP_ORDER: break; } } else { switch (type) { case IPSEC_ATTR_SA_LIFE_TYPE: lifetype = decode_16 (value); return 0; case IPSEC_ATTR_SA_LIFE_DURATION: switch (lifetype) { case IPSEC_DURATION_SECONDS: switch (len) { case 2: sa->seconds = decode_16 (value); break; case 4: sa->seconds = decode_32 (value); break; default: /* XXX Log. */ } break; case IPSEC_DURATION_KILOBYTES: switch (len) { case 2: sa->kilobytes = decode_16 (value); break; case 4: sa->kilobytes = decode_32 (value); break; default: /* XXX Log. */ } break; default: /* XXX Log! */ } break; case IPSEC_ATTR_GROUP_DESCRIPTION: isa->group_desc = decode_16 (value); break; case IPSEC_ATTR_ENCAPSULATION_MODE: /* XXX Multiple protocols must have same encapsulation mode, no? */ iproto->encap_mode = decode_16 (value); break; case IPSEC_ATTR_AUTHENTICATION_ALGORITHM: iproto->auth = decode_16 (value); break; case IPSEC_ATTR_KEY_LENGTH: iproto->keylen = decode_16 (value); break; case IPSEC_ATTR_KEY_ROUNDS: iproto->keyrounds = decode_16 (value); break; case IPSEC_ATTR_COMPRESS_DICTIONARY_SIZE: break; case IPSEC_ATTR_COMPRESS_PRIVATE_ALGORITHM: break; } } lifetype = 0; return 0; } /* * Walk over the attributes of the transform payload found in BUF, and * fill out the fields of the SA attached to MSG. Also mark the SA as * processed. */ void ipsec_decode_transform (struct message *msg, struct sa *sa, struct proto *proto, u_int8_t *buf) { struct ipsec_exch *ie = msg->exchange->data; struct ipsec_decode_arg ida; LOG_DBG ((LOG_MISC, 20, "ipsec_decode_transform: transform %d chosen", GET_ISAKMP_TRANSFORM_NO (buf))); ida.msg = msg; ida.sa = sa; ida.proto = proto; /* The default IKE lifetime is 8 hours. */ if (sa->phase == 1) sa->seconds = 28800; /* Extract the attributes and stuff them into the SA. */ attribute_map (buf + ISAKMP_TRANSFORM_SA_ATTRS_OFF, GET_ISAKMP_GEN_LENGTH (buf) - ISAKMP_TRANSFORM_SA_ATTRS_OFF, ipsec_decode_attribute, &ida); /* * If no pseudo-random function was negotiated, it's HMAC. * XXX As PRF_HMAC currently is zero, this is a no-op. */ if (!ie->prf_type) ie->prf_type = PRF_HMAC; } /* * Delete the IPSec SA represented by the INCOMING direction in protocol PROTO * of the IKE security association SA. */ static void ipsec_delete_spi (struct sa *sa, struct proto *proto, int incoming) { if (sa->phase == 1) return; /* XXX Error handling? Is it interesting? */ sysdep_ipsec_delete_spi (sa, proto, incoming); } /* * Store BUF into the g^x entry of the exchange that message MSG belongs to. * PEER is non-zero when the value is our peer's, and zero when it is ours. */ static int ipsec_g_x (struct message *msg, int peer, u_int8_t *buf) { struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; u_int8_t **g_x; int initiator = exchange->initiator ^ peer; char header[32]; g_x = initiator ? &ie->g_xi : &ie->g_xr; *g_x = malloc (ie->g_x_len); if (!*g_x) { log_error ("ipsec_g_x: malloc (%d) failed", ie->g_x_len); return -1; } memcpy (*g_x, buf, ie->g_x_len); snprintf (header, 32, "ipsec_g_x: g^x%c", initiator ? 'i' : 'r'); LOG_DBG_BUF ((LOG_MISC, 80, header, *g_x, ie->g_x_len)); return 0; } /* Generate our DH value. */ int ipsec_gen_g_x (struct message *msg) { struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; u_int8_t *buf; buf = malloc (ISAKMP_KE_SZ + ie->g_x_len); if (!buf) { log_error ("ipsec_gen_g_x: malloc (%d) failed", ISAKMP_KE_SZ + ie->g_x_len); return -1; } if (message_add_payload (msg, ISAKMP_PAYLOAD_KEY_EXCH, buf, ISAKMP_KE_SZ + ie->g_x_len, 1)) { free (buf); return -1; } if (dh_create_exchange (ie->group, buf + ISAKMP_KE_DATA_OFF)) { log_print ("ipsec_gen_g_x: dh_create_exchange failed"); free (buf); return -1; } return ipsec_g_x (msg, 0, buf + ISAKMP_KE_DATA_OFF); } /* Save the peer's DH value. */ int ipsec_save_g_x (struct message *msg) { struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; struct payload *kep; kep = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_KEY_EXCH]); kep->flags |= PL_MARK; ie->g_x_len = GET_ISAKMP_GEN_LENGTH (kep->p) - ISAKMP_KE_DATA_OFF; /* Check that the given length matches the group's expectancy. */ if (ie->g_x_len != dh_getlen (ie->group)) { /* XXX Is this a good notify type? */ message_drop (msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0); return -1; } return ipsec_g_x (msg, 1, kep->p + ISAKMP_KE_DATA_OFF); } /* * Get a SPI for PROTO and the transport MSG passed over. Store the * size where SZ points. NB! A zero return is OK if *SZ is zero. */ static u_int8_t * ipsec_get_spi (size_t *sz, u_int8_t proto, struct message *msg) { struct sockaddr *dst, *src; int dstlen, srclen; struct transport *transport = msg->transport; if (msg->exchange->phase == 1) { *sz = 0; return 0; } else { /* We are the destination in the SA we want a SPI for. */ transport->vtbl->get_src (transport, &dst, &dstlen); /* The peer is the source. */ transport->vtbl->get_dst (transport, &src, &srclen); return sysdep_ipsec_get_spi (sz, proto, src, srclen, dst, dstlen); } } /* * We have gotten a payload PAYLOAD of type TYPE, which did not get handled * by the logic of the exchange MSG takes part in. Now is the time to deal * with such a payload if we know how to, if we don't, return -1, otherwise * 0. */ int ipsec_handle_leftover_payload (struct message *msg, u_int8_t type, struct payload *payload) { struct sockaddr *dst; socklen_t dstlen; struct sa *sa; int flag = 0; /* So far, the only thing we handle is an INITIAL-CONTACT NOTIFY. */ switch (type) { case ISAKMP_PAYLOAD_NOTIFY: switch (GET_ISAKMP_NOTIFY_MSG_TYPE (payload->p)) { case IPSEC_NOTIFY_INITIAL_CONTACT: /* * Find out who is sending this and then delete every SA that is * ready. Exchanges will timeout themselves and then the * non-ready SAs will disappear too. */ msg->transport->vtbl->get_dst (msg->transport, &dst, &dstlen); while ((sa = sa_lookup_by_peer (dst, dstlen)) != 0) { /* * Don't delete the current SA -- we received the notification * over it, so it's obviously still active. We temporarily need * to remove the SA from the list to avoid an endless loop. */ if (sa == msg->isakmp_sa) { LIST_REMOVE (sa, link); flag = 1; continue; } LOG_DBG ((LOG_SA, 30, "ipsec_handle_leftover_payload: " "INITIAL-CONTACT made us delete SA %p", sa)); sa_delete (sa, 0); } if (flag) sa_enter (msg->isakmp_sa); payload->flags |= PL_MARK; return 0; break; } } return -1; } /* Return the encryption keylength in octets of the ESP protocol PROTO. */ int ipsec_esp_enckeylength (struct proto *proto) { struct ipsec_proto *iproto = proto->data; /* Compute the keylength to use. */ switch (proto->id) { case IPSEC_ESP_DES: case IPSEC_ESP_DES_IV32: case IPSEC_ESP_DES_IV64: return 8; case IPSEC_ESP_3DES: return 24; case IPSEC_ESP_CAST: if (!iproto->keylen) return 16; return iproto->keylen / 8; case IPSEC_ESP_AES: if (!iproto->keylen) return 16; /* Fallthrough */ default: return iproto->keylen / 8; } } /* Return the authentication keylength in octets of the ESP protocol PROTO. */ int ipsec_esp_authkeylength (struct proto *proto) { struct ipsec_proto *iproto = proto->data; switch (iproto->auth) { case IPSEC_AUTH_HMAC_MD5: return 16; case IPSEC_AUTH_HMAC_SHA: case IPSEC_AUTH_HMAC_RIPEMD: return 20; default: return 0; } } /* Return the authentication keylength in octets of the AH protocol PROTO. */ int ipsec_ah_keylength (struct proto *proto) { switch (proto->id) { case IPSEC_AH_MD5: return 16; case IPSEC_AH_SHA: case IPSEC_AH_RIPEMD: return 20; default: return -1; } } /* Return the total keymaterial length of the protocol PROTO. */ int ipsec_keymat_length (struct proto *proto) { switch (proto->proto) { case IPSEC_PROTO_IPSEC_ESP: return ipsec_esp_enckeylength (proto) + ipsec_esp_authkeylength (proto); case IPSEC_PROTO_IPSEC_AH: return ipsec_ah_keylength (proto); default: return -1; } } /* * Out of a named section SECTION in the configuration file find out * the network address and mask as well as the ID type. Put the info * in the areas pointed to by ADDR, MASK, TPROTO, PORT, and ID respectively. * Return 0 on success and -1 on failure. */ int ipsec_get_id (char *section, int *id, struct in_addr *addr, struct in_addr *mask, u_int8_t *tproto, u_int16_t *port) { char *type, *address, *netmask; type = conf_get_str (section, "ID-type"); if (!type) { log_print ("ipsec_get_id: section %s has no \"ID-type\" tag", section); return -1; } *id = constant_value (ipsec_id_cst, type); switch (*id) { case IPSEC_ID_IPV4_ADDR: address = conf_get_str (section, "Address"); if (!address) { log_print ("ipsec_get_id: section %s has no \"Address\" tag", section); return -1; } if (!inet_aton (address, addr)) { log_print ("ipsec_get_id: invalid address %s in section %s", section, address); return -1; } *tproto = conf_get_num (section, "Protocol", 0); if (*tproto) *port = conf_get_num (section, "Port", 0); break; #ifdef notyet case IPSEC_ID_FQDN: return -1; case IPSEC_ID_USER_FQDN: return -1; #endif case IPSEC_ID_IPV4_ADDR_SUBNET: address = conf_get_str (section, "Network"); if (!address) { log_print ("ipsec_get_id: section %s has no \"Network\" tag", section); return -1; } if (!inet_aton (address, addr)) { log_print ("ipsec_get_id: invalid section %s network %s", section, address); return -1; } netmask = conf_get_str (section, "Netmask"); if (!netmask) { log_print ("ipsec_get_id: section %s has no \"Netmask\" tag", section); return -1; } if (!inet_aton (netmask, mask)) { log_print ("ipsec_id_build: invalid section %s network %s", section, netmask); return -1; } *tproto = conf_get_num (section, "Protocol", 0); if (*tproto) *port = conf_get_num (section, "Port", 0); break; #ifdef notyet case IPSEC_ID_IPV6_ADDR: return -1; case IPSEC_ID_IPV6_ADDR_SUBNET: return -1; case IPSEC_ID_IPV4_RANGE: return -1; case IPSEC_ID_IPV6_RANGE: return -1; case IPSEC_ID_DER_ASN1_DN: return -1; case IPSEC_ID_DER_ASN1_GN: return -1; case IPSEC_ID_KEY_ID: return -1; #endif default: log_print ("ipsec_get_id: unknown ID type \"%s\" in section %s", type, section); return -1; } return 0; } #ifdef USE_DEBUG static void ipsec_ipv4toa (char *buf, size_t size, u_int8_t *addr) { #ifdef HAVE_GETNAMEINFO struct sockaddr_storage from; struct sockaddr_in *sfrom = (struct sockaddr_in *)&from; socklen_t fromlen = sizeof from; memset (&from, 0, fromlen); sfrom->sin_len = sizeof *sfrom; sfrom->sin_family = AF_INET; memcpy (&sfrom->sin_addr.s_addr, addr, sizeof sfrom->sin_addr.s_addr); if (getnameinfo ((struct sockaddr *)sfrom, sfrom->sin_len, buf, size, NULL, 0, NI_NUMERICHOST) != 0) { log_print ("ipsec_ipv4toa: getnameinfo () failed"); strcpy (buf, ""); } #else strncpy (buf, inet_ntoa (*(struct in_addr *)addr), size - 1); buf[size - 1] = '\0'; #endif /* HAVE_GETNAMEINFO */ } static void ipsec_decode_id (u_int8_t *buf, int size, u_int8_t *id, size_t id_len, int isakmpform) { int id_type; char ntop[NI_MAXHOST], ntop2[NI_MAXHOST]; if (id) { if (!isakmpform) { /* exchanges and SA's dont carry the IDs in ISAKMP form */ id -= ISAKMP_ID_TYPE_OFF; id_len += ISAKMP_ID_TYPE_OFF; } id_type = GET_ISAKMP_ID_TYPE (id); switch (id_type) { case IPSEC_ID_IPV4_ADDR: ipsec_ipv4toa (ntop, sizeof ntop, id + ISAKMP_ID_DATA_OFF); snprintf (buf, size, "%08x: %s", decode_32 (id + ISAKMP_ID_DATA_OFF), ntop); break; case IPSEC_ID_IPV4_ADDR_SUBNET: ipsec_ipv4toa (ntop, sizeof ntop, id + ISAKMP_ID_DATA_OFF); ipsec_ipv4toa (ntop2, sizeof ntop2, id + ISAKMP_ID_DATA_OFF + 4); snprintf (buf, size, "%08x/%08x: %s/%s", decode_32 (id + ISAKMP_ID_DATA_OFF), decode_32 (id + ISAKMP_ID_DATA_OFF + 4), ntop, ntop2); break; case IPSEC_ID_FQDN: case IPSEC_ID_USER_FQDN: /* String is not NUL terminated, be careful */ id_len -= ISAKMP_ID_DATA_OFF; id_len = MIN(id_len, size - 1); memcpy (buf, id + ISAKMP_ID_DATA_OFF, id_len); buf[id_len] = '\0'; break; /* XXX - IPV6 et al */ default: snprintf (buf, size, "", id_type); break; } } else snprintf (buf, size, ""); } char * ipsec_decode_ids (char *fmt, u_int8_t *id1, size_t id1_len, u_int8_t *id2, size_t id2_len, int isakmpform) { static char result[1024]; char s_id1[256], s_id2[256]; ipsec_decode_id(s_id1, sizeof s_id1, id1, id1_len, isakmpform); ipsec_decode_id(s_id2, sizeof s_id2, id2, id2_len, isakmpform); snprintf (result, sizeof result, fmt, s_id1, s_id2); return result; } #endif /* USE_DEBUG */ /* * Out of a named section SECTION in the configuration file build an * ISAKMP ID payload. Ths payload size should be stashed in SZ. * The caller is responsible for freeing the payload. */ u_int8_t * ipsec_build_id (char *section, size_t *sz) { struct in_addr addr, mask; u_int8_t *p; int id; u_int8_t tproto = 0; u_int16_t port = 0; if (ipsec_get_id (section, &id, &addr, &mask, &tproto, &port)) return 0; *sz = ISAKMP_ID_SZ; switch (id) { case IPSEC_ID_IPV4_ADDR: *sz += sizeof addr; break; case IPSEC_ID_IPV4_ADDR_SUBNET: *sz += sizeof addr + sizeof mask; break; } p = malloc (*sz); if (!p) { log_print ("ipsec_build_id: malloc(%d) failed", *sz); return 0; } SET_ISAKMP_ID_TYPE (p, id); SET_ISAKMP_ID_DOI_DATA (p, "\000\000\000"); switch (id) { case IPSEC_ID_IPV4_ADDR: encode_32 (p + ISAKMP_ID_DATA_OFF, ntohl (addr.s_addr)); SET_IPSEC_ID_PROTO (p + ISAKMP_ID_DOI_DATA_OFF, tproto); SET_IPSEC_ID_PORT (p + ISAKMP_ID_DOI_DATA_OFF, port); break; case IPSEC_ID_IPV4_ADDR_SUBNET: encode_32 (p + ISAKMP_ID_DATA_OFF, ntohl (addr.s_addr)); encode_32 (p + ISAKMP_ID_DATA_OFF + 4, ntohl (mask.s_addr)); SET_IPSEC_ID_PROTO (p + ISAKMP_ID_DOI_DATA_OFF, tproto); SET_IPSEC_ID_PORT (p + ISAKMP_ID_DOI_DATA_OFF, port); break; } return p; } /* * copy an ISAKMPD id */ int ipsec_clone_id (u_int8_t **did, size_t *did_len, u_int8_t *id, size_t id_len) { if (*did) free (*did); if (!id_len || id == NULL) { *did = NULL; *did_len = 0; return 0; } *did = malloc (id_len); if (*did == NULL) { *did_len = 0; log_error ("ipsec_clone_id: malloc(%d) failed", id_len); return -1; } *did_len = id_len; memcpy (*did, id, id_len); return 0; } /* * IPSec-specific PROTO initializations. SECTION is only set if we are the * initiator thus only usable there. * XXX I want to fix this later. */ void ipsec_proto_init (struct proto *proto, char *section) { struct ipsec_proto *iproto = proto->data; if (proto->sa->phase == 2 && section) iproto->replay_window = conf_get_num (section, "ReplayWindow", DEFAULT_REPLAY_WINDOW); } /* * Add a notification payload of type INITIAL CONTACT to MSG if this is * the first contact we have made to our peer. */ int ipsec_initial_contact (struct message *msg) { u_int8_t *buf; if (ipsec_contacted (msg)) return 0; buf = malloc (ISAKMP_NOTIFY_SZ + ISAKMP_HDR_COOKIES_LEN); if (!buf) { log_error ("ike_phase_1_initial_contact: malloc (%d) failed", ISAKMP_NOTIFY_SZ + ISAKMP_HDR_COOKIES_LEN); return -1; } SET_ISAKMP_NOTIFY_DOI (buf, IPSEC_DOI_IPSEC); SET_ISAKMP_NOTIFY_PROTO (buf, ISAKMP_PROTO_ISAKMP); SET_ISAKMP_NOTIFY_SPI_SZ (buf, ISAKMP_HDR_COOKIES_LEN); SET_ISAKMP_NOTIFY_MSG_TYPE (buf, IPSEC_NOTIFY_INITIAL_CONTACT); memcpy (buf + ISAKMP_NOTIFY_SPI_OFF, msg->isakmp_sa->cookies, ISAKMP_HDR_COOKIES_LEN); if (message_add_payload (msg, ISAKMP_PAYLOAD_NOTIFY, buf, ISAKMP_NOTIFY_SZ + ISAKMP_HDR_COOKIES_LEN, 1)) { free (buf); return -1; } return ipsec_add_contact (msg); } /* * Compare the two contacts pointed to by A and B. Return negative if * *A < *B, 0 if they are equal, and positive if *A is the largest of them. */ static int addr_cmp (const void *a, const void *b) { const struct contact *x = a, *y = b; int minlen = MIN (x->len, y->len); int rv = memcmp (x->addr, y->addr, minlen); return rv ? rv : (x->len - y->len); } /* * Add the peer that MSG is bound to as an address we don't want to send * INITIAL CONTACT too from now on. Do not call this function with a * specific address duplicate times. We want fast lookup, speed of insertion * is unimportant, if this is to scale. */ static int ipsec_add_contact (struct message *msg) { struct contact *new_contacts; struct sockaddr *dst, *addr; socklen_t dstlen; int cnt; if (contact_cnt == contact_limit) { cnt = contact_limit ? 2 * contact_limit : 64; new_contacts = realloc (contacts, cnt * sizeof contacts[0]); if (!new_contacts) { log_error ("ipsec_add_contact: realloc (%p, %d) failed", contacts, cnt * sizeof contacts[0]); return -1; } contact_limit = cnt; contacts = new_contacts; } msg->transport->vtbl->get_dst (msg->transport, &dst, &dstlen); addr = malloc (dstlen); if (!addr) { log_error ("ipsec_add_contact: malloc (%d) failed", dstlen); return -1; } memcpy (addr, dst, dstlen); contacts[contact_cnt].addr = addr; contacts[contact_cnt++].len = dstlen; /* * XXX There are better algorithms for already mostly-sorted data like * this, but only qsort is standard. I will someday do this inline. */ qsort (contacts, contact_cnt, sizeof *contacts, addr_cmp); return 0; } /* Return true if the recipient of MSG has already been contacted. */ static int ipsec_contacted (struct message *msg) { struct contact contact; msg->transport->vtbl->get_dst (msg->transport, &contact.addr, &contact.len); return contacts ? (bsearch (&contact, contacts, contact_cnt, sizeof *contacts, addr_cmp) != 0) : 0; } /* Add a HASH for to MSG. */ u_int8_t * ipsec_add_hash_payload (struct message *msg, size_t hashsize) { u_int8_t *buf; buf = malloc (ISAKMP_HASH_SZ + hashsize); if (!buf) { log_error ("ipsec_add_hash_payload: malloc (%d) failed", ISAKMP_HASH_SZ + hashsize); return 0; } if (message_add_payload (msg, ISAKMP_PAYLOAD_HASH, buf, ISAKMP_HASH_SZ + hashsize, 1)) { free (buf); return 0; } return buf; } /* Fill in the HASH payload of MSG. */ int ipsec_fill_in_hash (struct message *msg) { struct exchange *exchange = msg->exchange; struct sa *isakmp_sa = msg->isakmp_sa; struct ipsec_sa *isa = isakmp_sa->data; struct hash *hash = hash_get (isa->hash); struct prf *prf; struct payload *payload; u_int8_t *buf; int i; char header[80]; /* If no SKEYID_a, we need not do anything. */ if (!isa->skeyid_a) return 0; payload = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_HASH]); if (!payload) { log_print ("ipsec_fill_in_hash: no HASH payload found"); return -1; } buf = payload->p; /* Allocate the prf and start calculating our HASH(1). */ LOG_DBG_BUF ((LOG_MISC, 90, "ipsec_fill_in_hash: SKEYID_a", isa->skeyid_a, isa->skeyid_len)); prf = prf_alloc (isa->prf_type, hash->type, isa->skeyid_a, isa->skeyid_len); if (!prf) return -1; prf->Init (prf->prfctx); LOG_DBG_BUF ((LOG_MISC, 90, "ipsec_fill_in_hash: message_id", exchange->message_id, ISAKMP_HDR_MESSAGE_ID_LEN)); prf->Update (prf->prfctx, exchange->message_id, ISAKMP_HDR_MESSAGE_ID_LEN); /* Loop over all payloads after HASH(1). */ for (i = 2; i < msg->iovlen; i++) { /* XXX Misleading payload type printouts. */ snprintf (header, 80, "ipsec_fill_in_hash: payload %d after HASH(1)", i - 1); LOG_DBG_BUF ((LOG_MISC, 90, header, msg->iov[i].iov_base, msg->iov[i].iov_len)); prf->Update (prf->prfctx, msg->iov[i].iov_base, msg->iov[i].iov_len); } prf->Final (buf + ISAKMP_HASH_DATA_OFF, prf->prfctx); prf_free (prf); LOG_DBG_BUF ((LOG_MISC, 80, "ipsec_fill_in_hash: HASH(1)", buf + ISAKMP_HASH_DATA_OFF, hash->hashsize)); return 0; } /* Add a HASH payload to MSG, if we have an ISAKMP SA we're protected by. */ static int ipsec_informational_pre_hook (struct message *msg) { struct sa *isakmp_sa = msg->isakmp_sa; struct ipsec_sa *isa; struct hash *hash; if (!isakmp_sa) return 0; isa = isakmp_sa->data; hash = hash_get (isa->hash); return ipsec_add_hash_payload (msg, hash->hashsize) == 0; } /* * Fill in the HASH payload in MSG, if we have an ISAKMP SA we're protected by. */ static int ipsec_informational_post_hook (struct message *msg) { if (!msg->isakmp_sa) return 0; return ipsec_fill_in_hash (msg); } ssize_t ipsec_id_size (char *section, u_int8_t *id) { char *type, *data; type = conf_get_str (section, "ID-type"); if (!type) { log_print ("ipsec_id_size: section %s has no \"ID-type\" tag", section); return -1; } *id = constant_value (ipsec_id_cst, type); switch (*id) { case IPSEC_ID_IPV4_ADDR: return sizeof (in_addr_t); case IPSEC_ID_IPV4_ADDR_SUBNET: return 2 * sizeof (in_addr_t); case IPSEC_ID_FQDN: case IPSEC_ID_USER_FQDN: data = conf_get_str (section, "Name"); if (!data) { log_print ("ipsec_id_size: section %s has no \"Name\" tag", section); return -1; } return strlen (data); } log_print ("ipsec_id_size: unrecognized ID-type %d (%s)", *id, type); return -1; }