/* $OpenBSD: ike_phase_1.c,v 1.44 2004/02/27 10:16:26 ho Exp $ */ /* $EOM: ike_phase_1.c,v 1.31 2000/12/11 23:47:56 niklas Exp $ */ /* * Copyright (c) 1999, 2000 Niklas Hallqvist. All rights reserved. * Copyright (c) 1999, 2000 Angelos D. Keromytis. All rights reserved. * Copyright (c) 2001, 2004 Håkan Olsson. 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. * * 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 "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_auth.h" #include "ike_phase_1.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 "transport.h" #include "util.h" static int attribute_unacceptable (u_int16_t, u_int8_t *, u_int16_t, void *); static int ike_phase_1_validate_prop (struct exchange *, struct sa *, struct sa *); /* Offer a set of transforms to the responder in the MSG message. */ int ike_phase_1_initiator_send_SA (struct message *msg) { struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; u_int8_t *proposal = 0, *sa_buf = 0, *saved_nextp, *attr; u_int8_t **transform = 0; size_t transforms_len = 0, proposal_len, sa_len; size_t *transform_len = 0; struct conf_list *conf, *life_conf; struct conf_list_node *xf, *life; int i, value, update_nextp; struct payload *p; struct proto *proto; struct proto_attr *pa; int group_desc = -1, new_group_desc; /* Get the list of transforms. */ conf = conf_get_list (exchange->policy, "Transforms"); if (!conf) return -1; transform = calloc (conf->cnt, sizeof *transform); if (!transform) { log_error ("ike_phase_1_initiator_send_SA: calloc (%d, %lu) failed", conf->cnt, (unsigned long)sizeof *transform); goto bail_out; } transform_len = calloc (conf->cnt, sizeof *transform_len); if (!transform_len) { log_error ("ike_phase_1_initiator_send_SA: calloc (%d, %lu) failed", conf->cnt, (unsigned long)sizeof *transform_len); goto bail_out; } for (xf = TAILQ_FIRST (&conf->fields), i = 0; i < conf->cnt; i++, xf = TAILQ_NEXT (xf, link)) { /* XXX The sizing needs to be dynamic. */ transform[i] = malloc (ISAKMP_TRANSFORM_SA_ATTRS_OFF + 16 * ISAKMP_ATTR_VALUE_OFF); if (!transform[i]) { log_error ("ike_phase_1_initiator_send_SA: malloc (%d) failed", ISAKMP_TRANSFORM_SA_ATTRS_OFF + 16 * ISAKMP_ATTR_VALUE_OFF); goto bail_out; } SET_ISAKMP_TRANSFORM_NO (transform[i], i); SET_ISAKMP_TRANSFORM_ID (transform[i], IPSEC_TRANSFORM_KEY_IKE); SET_ISAKMP_TRANSFORM_RESERVED (transform[i], 0); attr = transform[i] + ISAKMP_TRANSFORM_SA_ATTRS_OFF; if (attribute_set_constant (xf->field, "ENCRYPTION_ALGORITHM", ike_encrypt_cst, IKE_ATTR_ENCRYPTION_ALGORITHM, &attr)) goto bail_out; if (attribute_set_constant (xf->field, "HASH_ALGORITHM", ike_hash_cst, IKE_ATTR_HASH_ALGORITHM, &attr)) goto bail_out; if (attribute_set_constant (xf->field, "AUTHENTICATION_METHOD", ike_auth_cst, IKE_ATTR_AUTHENTICATION_METHOD, &attr)) goto bail_out; if (attribute_set_constant (xf->field, "GROUP_DESCRIPTION", ike_group_desc_cst, IKE_ATTR_GROUP_DESCRIPTION, &attr)) { /* * If no group description exists, try looking for a user-defined * one. */ if (attribute_set_constant (xf->field, "GROUP_TYPE", ike_group_cst, IKE_ATTR_GROUP_TYPE, &attr)) goto bail_out; #if 0 if (attribute_set_bignum (xf->field, "GROUP_PRIME", IKE_ATTR_GROUP_PRIME, &attr)) goto bail_out; if (attribute_set_bignum (xf->field, "GROUP_GENERATOR_2", IKE_ATTR_GROUP_GENERATOR_2, &attr)) goto bail_out; if (attribute_set_bignum (xf->field, "GROUP_GENERATOR_2", IKE_ATTR_GROUP_GENERATOR_2, &attr)) goto bail_out; if (attribute_set_bignum (xf->field, "GROUP_CURVE_A", IKE_ATTR_GROUP_CURVE_A, &attr)) goto bail_out; if (attribute_set_bignum (xf->field, "GROUP_CURVE_B", IKE_ATTR_GROUP_CURVE_B, &attr)) goto bail_out; #endif } /* * Life durations are special, we should be able to specify * several, one per type. */ life_conf = conf_get_list (xf->field, "Life"); if (life_conf) { for (life = TAILQ_FIRST (&life_conf->fields); life; life = TAILQ_NEXT (life, link)) { attribute_set_constant (life->field, "LIFE_TYPE", ike_duration_cst, IKE_ATTR_LIFE_TYPE, &attr); /* XXX Deals with 16 and 32 bit lifetimes only */ value = conf_get_num (life->field, "LIFE_DURATION", 0); if (value) { if (value <= 0xffff) attr = attribute_set_basic (attr, IKE_ATTR_LIFE_DURATION, value); else { value = htonl (value); attr = attribute_set_var (attr, IKE_ATTR_LIFE_DURATION, (u_int8_t *)&value, sizeof value); } } } conf_free_list (life_conf); } attribute_set_constant (xf->field, "PRF", ike_prf_cst, IKE_ATTR_PRF, &attr); value = conf_get_num (xf->field, "KEY_LENGTH", 0); if (value) attr = attribute_set_basic (attr, IKE_ATTR_KEY_LENGTH, value); value = conf_get_num (xf->field, "FIELD_SIZE", 0); if (value) attr = attribute_set_basic (attr, IKE_ATTR_FIELD_SIZE, value); value = conf_get_num (xf->field, "GROUP_ORDER", 0); if (value) attr = attribute_set_basic (attr, IKE_ATTR_GROUP_ORDER, value); /* Record the real transform size. */ transforms_len += transform_len[i] = attr - transform[i]; /* XXX I don't like exchange-specific stuff in here. */ if (exchange->type == ISAKMP_EXCH_AGGRESSIVE) { /* * Make sure that if a group description is specified, it is * specified for all transforms equally. */ attr = (u_int8_t *)conf_get_str (xf->field, "GROUP_DESCRIPTION"); new_group_desc = attr ? constant_value (ike_group_desc_cst, (char *)attr) : 0; if (group_desc == -1) group_desc = new_group_desc; else if (group_desc != new_group_desc) { log_print ("ike_phase_1_initiator_send_SA: " "differing group descriptions in a proposal"); goto bail_out; } } /* We need to check that we actually support our configuration. */ if (attribute_map (transform[i] + ISAKMP_TRANSFORM_SA_ATTRS_OFF, transform_len[i] - ISAKMP_TRANSFORM_SA_ATTRS_OFF, exchange->doi->is_attribute_incompatible, msg)) { log_print ("ike_phase_1_initiator_send_SA: " "section [%s] has unsupported attribute(s)", xf->field); goto bail_out; } } /* XXX I don't like exchange-specific stuff in here. */ if (exchange->type == ISAKMP_EXCH_AGGRESSIVE) ie->group = group_get (group_desc); proposal_len = ISAKMP_PROP_SPI_OFF; proposal = malloc (proposal_len); if (!proposal) { log_error ("ike_phase_1_initiator_send_SA: malloc (%lu) failed", (unsigned long)proposal_len); goto bail_out; } SET_ISAKMP_PROP_NO (proposal, 1); SET_ISAKMP_PROP_PROTO (proposal, ISAKMP_PROTO_ISAKMP); SET_ISAKMP_PROP_SPI_SZ (proposal, 0); SET_ISAKMP_PROP_NTRANSFORMS (proposal, conf->cnt); /* XXX I would like to see this factored out. */ proto = calloc (1, sizeof *proto); if (!proto) { log_error ("ike_phase_1_initiator_send_SA: calloc (1, %lu) failed", (unsigned long)sizeof *proto); goto bail_out; } proto->no = 1; proto->proto = ISAKMP_PROTO_ISAKMP; proto->sa = TAILQ_FIRST (&exchange->sa_list); proto->xf_cnt = conf->cnt; TAILQ_INIT (&proto->xfs); for (i = 0; i < proto->xf_cnt; i++) { pa = (struct proto_attr *)calloc (1, sizeof *pa); if (!pa) goto bail_out; pa->len = transform_len[i]; pa->attrs = (u_int8_t *)malloc (pa->len); if (!pa->attrs) { free (pa); goto bail_out; } memcpy (pa->attrs, transform[i], pa->len); TAILQ_INSERT_TAIL (&proto->xfs, pa, next); } TAILQ_INSERT_TAIL (&TAILQ_FIRST (&exchange->sa_list)->protos, proto, link); sa_len = ISAKMP_SA_SIT_OFF + IPSEC_SIT_SIT_LEN; sa_buf = malloc (sa_len); if (!sa_buf) { log_error ("ike_phase_1_initiator_send_SA: malloc (%lu) failed", (unsigned long)sa_len); goto bail_out; } SET_ISAKMP_SA_DOI (sa_buf, IPSEC_DOI_IPSEC); SET_IPSEC_SIT_SIT (sa_buf + ISAKMP_SA_SIT_OFF, IPSEC_SIT_IDENTITY_ONLY); /* * Add the payloads. As this is a SA, we need to recompute the * lengths of the payloads containing others. */ if (message_add_payload (msg, ISAKMP_PAYLOAD_SA, sa_buf, sa_len, 1)) goto bail_out; SET_ISAKMP_GEN_LENGTH (sa_buf, sa_len + proposal_len + transforms_len); sa_buf = 0; saved_nextp = msg->nextp; if (message_add_payload (msg, ISAKMP_PAYLOAD_PROPOSAL, proposal, proposal_len, 0)) goto bail_out; SET_ISAKMP_GEN_LENGTH (proposal, proposal_len + transforms_len); proposal = 0; update_nextp = 0; for (i = 0; i < conf->cnt; i++) { if (message_add_payload (msg, ISAKMP_PAYLOAD_TRANSFORM, transform[i], transform_len[i], update_nextp)) goto bail_out; update_nextp = 1; transform[i] = 0; } msg->nextp = saved_nextp; /* Save SA payload body in ie->sa_i_b, length ie->sa_i_b_len. */ ie->sa_i_b_len = sa_len + proposal_len + transforms_len - ISAKMP_GEN_SZ; ie->sa_i_b = malloc (ie->sa_i_b_len); if (!ie->sa_i_b) { log_error ("ike_phase_1_initiator_send_SA: malloc (%lu) failed", (unsigned long)ie->sa_i_b_len); goto bail_out; } memcpy (ie->sa_i_b, TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_SA])->p + ISAKMP_GEN_SZ, sa_len - ISAKMP_GEN_SZ); memcpy (ie->sa_i_b + sa_len - ISAKMP_GEN_SZ, TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_PROPOSAL])->p, proposal_len); transforms_len = 0; for (i = 0, p = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_TRANSFORM]); i < conf->cnt; i++, p = TAILQ_NEXT (p, link)) { memcpy (ie->sa_i_b + sa_len + proposal_len + transforms_len - ISAKMP_GEN_SZ, p->p, transform_len[i]); transforms_len += transform_len[i]; } conf_free_list (conf); free (transform); free (transform_len); return 0; bail_out: if (sa_buf) free (sa_buf); if (proposal) free (proposal); if (transform) { for (i = 0; i < conf->cnt; i++) if (transform[i]) free (transform[i]); free (transform); } if (transform_len) free (transform_len); conf_free_list (conf); return -1; } /* Figure out what transform the responder chose. */ int ike_phase_1_initiator_recv_SA (struct message *msg) { struct exchange *exchange = msg->exchange; struct sa *sa = TAILQ_FIRST (&exchange->sa_list); struct ipsec_exch *ie = exchange->data; struct ipsec_sa *isa = sa->data; struct payload *sa_p = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_SA]); struct payload *prop = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_PROPOSAL]); struct payload *xf = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_TRANSFORM]); /* * IKE requires that only one SA with only one proposal exists and since * we are getting an answer on our transform offer, only one transform. */ if (TAILQ_NEXT (sa_p, link) || TAILQ_NEXT (prop, link) || TAILQ_NEXT (xf, link)) { log_print ("ike_phase_1_initiator_recv_SA: " "multiple SA, proposal or transform payloads in phase 1"); /* XXX Is there a better notification type? */ message_drop (msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0); return -1; } /* Check that the chosen transform matches an offer. */ if (message_negotiate_sa (msg, ike_phase_1_validate_prop) || !TAILQ_FIRST (&sa->protos)) return -1; ipsec_decode_transform (msg, sa, TAILQ_FIRST (&sa->protos), xf->p); /* XXX I don't like exchange-specific stuff in here. */ if (exchange->type != ISAKMP_EXCH_AGGRESSIVE) ie->group = group_get (isa->group_desc); /* Mark the SA as handled. */ sa_p->flags |= PL_MARK; return 0; } /* Send our public DH value and a nonce to the responder. */ int ike_phase_1_initiator_send_KE_NONCE (struct message *msg) { struct ipsec_exch *ie = msg->exchange->data; ie->g_x_len = dh_getlen (ie->group); /* XXX I want a better way to specify the nonce's size. */ return ike_phase_1_send_KE_NONCE (msg, 16); } /* Accept responder's public DH value and nonce. */ int ike_phase_1_initiator_recv_KE_NONCE (struct message *msg) { if (ike_phase_1_recv_KE_NONCE (msg)) return -1; return ike_phase_1_post_exchange_KE_NONCE (msg); } /* * Accept a set of transforms offered by the initiator and chose one we can * handle. */ int ike_phase_1_responder_recv_SA (struct message *msg) { struct exchange *exchange = msg->exchange; struct sa *sa = TAILQ_FIRST (&exchange->sa_list); struct ipsec_sa *isa = sa->data; struct payload *sa_p = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_SA]); struct payload *prop = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_PROPOSAL]); struct ipsec_exch *ie = exchange->data; /* Mark the SA as handled. */ sa_p->flags |= PL_MARK; /* IKE requires that only one SA with only one proposal exists. */ if (TAILQ_NEXT (sa_p, link) || TAILQ_NEXT (prop, link)) { log_print ("ike_phase_1_responder_recv_SA: " "multiple SA or proposal payloads in phase 1"); /* XXX Is there a better notification type? */ message_drop (msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0); return -1; } /* Chose a transform from the SA. */ if (message_negotiate_sa (msg, ike_phase_1_validate_prop) || !TAILQ_FIRST (&sa->protos)) return -1; /* XXX Move into message_negotiate_sa? */ ipsec_decode_transform (msg, sa, TAILQ_FIRST (&sa->protos), TAILQ_FIRST (&sa->protos)->chosen->p); ie->group = group_get (isa->group_desc); /* * Check that the mandatory attributes: encryption, hash, authentication * method and Diffie-Hellman group description, has been supplied. */ if (!exchange->crypto || !ie->hash || !ie->ike_auth || !ie->group) { message_drop (msg, ISAKMP_NOTIFY_PAYLOAD_MALFORMED, 0, 1, 0); return -1; } /* Save the body for later hash computation. */ ie->sa_i_b_len = GET_ISAKMP_GEN_LENGTH (sa_p->p) - ISAKMP_GEN_SZ; ie->sa_i_b = malloc (ie->sa_i_b_len); if (!ie->sa_i_b) { /* XXX How to notify peer? */ log_error ("ike_phase_1_responder_recv_SA: malloc (%lu) failed", (unsigned long)ie->sa_i_b_len); return -1; } memcpy (ie->sa_i_b, sa_p->p + ISAKMP_GEN_SZ, ie->sa_i_b_len); return 0; } /* Reply with the transform we chose. */ int ike_phase_1_responder_send_SA (struct message *msg) { /* Add the SA payload with the transform that was chosen. */ return message_add_sa_payload (msg); } /* Send our public DH value and a nonce to the peer. */ int ike_phase_1_send_KE_NONCE (struct message *msg, size_t nonce_sz) { /* Public DH key. */ if (ipsec_gen_g_x (msg)) { /* XXX How to log and notify peer? */ return -1; } /* Generate a nonce, and add it to the message. */ if (exchange_gen_nonce (msg, nonce_sz)) { /* XXX Log? */ return -1; } /* Try to add certificates which are acceptable for the CERTREQs */ if (exchange_add_certs (msg)) { /* XXX Log? */ return -1; } return 0; } /* Receive our peer's public DH value and nonce. */ int ike_phase_1_recv_KE_NONCE (struct message *msg) { /* Copy out the initiator's DH public value. */ if (ipsec_save_g_x (msg)) { /* XXX How to log and notify peer? */ return -1; } /* Copy out the initiator's nonce. */ if (exchange_save_nonce (msg)) { /* XXX How to log and notify peer? */ return -1; } /* Copy out the initiator's cert requests. */ if (exchange_save_certreq (msg)) { /* XXX How to log and notify peer? */ return -1; } return 0; } /* * Compute DH values and key material. This is done in a post-send function * as that means we can do parallel work in both the initiator and responder * thus speeding up exchanges. */ int ike_phase_1_post_exchange_KE_NONCE (struct message *msg) { struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; struct prf *prf; struct hash *hash = ie->hash; enum cryptoerr err; /* Compute Diffie-Hellman shared value. */ ie->g_xy = malloc (ie->g_x_len); if (!ie->g_xy) { /* XXX How to notify peer? */ log_error ("ike_phase_1_post_exchange_KE_NONCE: malloc (%lu) failed", (unsigned long)ie->g_x_len); return -1; } if (dh_create_shared (ie->group, ie->g_xy, exchange->initiator ? ie->g_xr : ie->g_xi)) { log_print ("ike_phase_1_post_exchange_KE_NONCE: " "dh_create_shared failed"); return -1; } LOG_DBG_BUF ((LOG_NEGOTIATION, 80, "ike_phase_1_post_exchange_KE_NONCE: g^xy", ie->g_xy, ie->g_x_len)); /* Compute the SKEYID depending on the authentication method. */ ie->skeyid = ie->ike_auth->gen_skeyid (exchange, &ie->skeyid_len); if (!ie->skeyid) { /* XXX Log and teardown? */ return -1; } LOG_DBG_BUF ((LOG_NEGOTIATION, 80, "ike_phase_1_post_exchange_KE_NONCE: SKEYID", ie->skeyid, ie->skeyid_len)); /* SKEYID_d. */ ie->skeyid_d = malloc (ie->skeyid_len); if (!ie->skeyid_d) { /* XXX How to notify peer? */ log_error ("ike_phase_1_post_exchange_KE_NONCE: malloc (%lu) failed", (unsigned long)ie->skeyid_len); return -1; } prf = prf_alloc (ie->prf_type, hash->type, ie->skeyid, ie->skeyid_len); if (!prf) { /* XXX Log and teardown? */ return -1; } prf->Init (prf->prfctx); prf->Update (prf->prfctx, ie->g_xy, ie->g_x_len); prf->Update (prf->prfctx, exchange->cookies, ISAKMP_HDR_COOKIES_LEN); prf->Update (prf->prfctx, (unsigned char *)"\0", 1); prf->Final (ie->skeyid_d, prf->prfctx); LOG_DBG_BUF ((LOG_NEGOTIATION, 80, "ike_phase_1_post_exchange_KE_NONCE: SKEYID_d", ie->skeyid_d, ie->skeyid_len)); /* SKEYID_a. */ ie->skeyid_a = malloc (ie->skeyid_len); if (!ie->skeyid_a) { log_error ("ike_phase_1_post_exchange_KE_NONCE: malloc (%lu) failed", (unsigned long)ie->skeyid_len); prf_free (prf); return -1; } prf->Init (prf->prfctx); prf->Update (prf->prfctx, ie->skeyid_d, ie->skeyid_len); prf->Update (prf->prfctx, ie->g_xy, ie->g_x_len); prf->Update (prf->prfctx, exchange->cookies, ISAKMP_HDR_COOKIES_LEN); prf->Update (prf->prfctx, (unsigned char *)"\1", 1); prf->Final (ie->skeyid_a, prf->prfctx); LOG_DBG_BUF ((LOG_NEGOTIATION, 80, "ike_phase_1_post_exchange_KE_NONCE: SKEYID_a", ie->skeyid_a, ie->skeyid_len)); /* SKEYID_e. */ ie->skeyid_e = malloc (ie->skeyid_len); if (!ie->skeyid_e) { /* XXX How to notify peer? */ log_error ("ike_phase_1_post_exchange_KE_NONCE: malloc (%lu) failed", (unsigned long)ie->skeyid_len); prf_free (prf); return -1; } prf->Init (prf->prfctx); prf->Update (prf->prfctx, ie->skeyid_a, ie->skeyid_len); prf->Update (prf->prfctx, ie->g_xy, ie->g_x_len); prf->Update (prf->prfctx, exchange->cookies, ISAKMP_HDR_COOKIES_LEN); prf->Update (prf->prfctx, (unsigned char *)"\2", 1); prf->Final (ie->skeyid_e, prf->prfctx); prf_free (prf); LOG_DBG_BUF ((LOG_NEGOTIATION, 80, "ike_phase_1_post_exchange_KE_NONCE: SKEYID_e", ie->skeyid_e, ie->skeyid_len)); /* Key length determination. */ if (!exchange->key_length) exchange->key_length = exchange->crypto->keymax; /* Derive a longer key from skeyid_e */ if (ie->skeyid_len < exchange->key_length) { u_int16_t len, keylen; u_int8_t *key, *p; prf = prf_alloc (ie->prf_type, hash->type, ie->skeyid_e, ie->skeyid_len); if (!prf) { /* XXX - notify peer */ return -1; } /* Make keylen a multiple of prf->blocksize */ keylen = exchange->key_length; if (keylen % prf->blocksize) keylen += prf->blocksize - (keylen % prf->blocksize); key = malloc (keylen); if (!key) { /* XXX - Notify peer. */ log_error ("ike_phase_1_post_exchange_KE_NONCE: malloc (%d) failed", keylen); return -1; } prf->Init (prf->prfctx); prf->Update (prf->prfctx, (unsigned char *)"\0", 1); prf->Final (key, prf->prfctx); for (len = prf->blocksize, p = key; len < exchange->key_length; len += prf->blocksize, p += prf->blocksize) { prf->Init (prf->prfctx); prf->Update (prf->prfctx, p, prf->blocksize); prf->Final (p + prf->blocksize, prf->prfctx); } prf_free (prf); /* Setup our keystate using the derived encryption key. */ exchange->keystate = crypto_init (exchange->crypto, key, exchange->key_length, &err); free (key); } else /* Setup our keystate using the raw skeyid_e. */ exchange->keystate = crypto_init (exchange->crypto, ie->skeyid_e, exchange->key_length, &err); /* Special handling for DES weak keys. */ if (!exchange->keystate && err == EWEAKKEY && (exchange->key_length << 1) <= ie->skeyid_len) { log_print ("ike_phase_1_post_exchange_KE_NONCE: " "weak key, trying subseq. skeyid_e"); exchange->keystate = crypto_init (exchange->crypto, ie->skeyid_e + exchange->key_length, exchange->key_length, &err); } if (!exchange->keystate) { log_print ("ike_phase_1_post_exchange_KE_NONCE: " "exchange->crypto->init () failed: %d", err); /* * XXX We really need to know if problems are of transient nature * or fatal (like failed assertions etc.) */ return -1; } /* Setup IV. XXX Only for CBC transforms, no? */ hash->Init (hash->ctx); hash->Update (hash->ctx, ie->g_xi, ie->g_x_len); hash->Update (hash->ctx, ie->g_xr, ie->g_x_len); hash->Final (hash->digest, hash->ctx); crypto_init_iv (exchange->keystate, hash->digest, exchange->crypto->blocksize); return 0; } int ike_phase_1_responder_send_ID_AUTH (struct message *msg) { if (ike_phase_1_send_ID (msg)) return -1; return ike_phase_1_send_AUTH (msg); } int ike_phase_1_send_ID (struct message *msg) { struct exchange *exchange = msg->exchange; u_int8_t *buf; char header[80]; ssize_t sz; struct sockaddr *src; int initiator = exchange->initiator; u_int8_t **id; size_t *id_len; char *my_id = 0; u_int8_t id_type; /* Choose the right fields to fill-in. */ id = initiator ? &exchange->id_i : &exchange->id_r; id_len = initiator ? &exchange->id_i_len : &exchange->id_r_len; if (exchange->name) my_id = conf_get_str (exchange->name, "ID"); if (!my_id) my_id = conf_get_str ("General", "Default-phase-1-ID"); msg->transport->vtbl->get_src (msg->transport, &src); sz = my_id ? ipsec_id_size (my_id, &id_type) : sockaddr_addrlen (src); if (sz == -1) return -1; sz += ISAKMP_ID_DATA_OFF; buf = malloc (sz); if (!buf) { log_error ("ike_phase_1_send_ID: malloc (%lu) failed", (unsigned long)sz); return -1; } SET_IPSEC_ID_PROTO (buf + ISAKMP_ID_DOI_DATA_OFF, 0); SET_IPSEC_ID_PORT (buf + ISAKMP_ID_DOI_DATA_OFF, 0); if (my_id) { SET_ISAKMP_ID_TYPE (buf, id_type); switch (id_type) { case IPSEC_ID_IPV4_ADDR: case IPSEC_ID_IPV6_ADDR: /* Already in network byteorder. */ memcpy (buf + ISAKMP_ID_DATA_OFF, sockaddr_addrdata (src), sockaddr_addrlen (src)); break; case IPSEC_ID_FQDN: case IPSEC_ID_USER_FQDN: case IPSEC_ID_KEY_ID: memcpy (buf + ISAKMP_ID_DATA_OFF, conf_get_str (my_id, "Name"), sz - ISAKMP_ID_DATA_OFF); break; default: log_print ("ike_phase_1_send_ID: unsupported ID type %d", id_type); free (buf); return -1; } } else { switch (src->sa_family) { case AF_INET: SET_ISAKMP_ID_TYPE (buf, IPSEC_ID_IPV4_ADDR); break; case AF_INET6: SET_ISAKMP_ID_TYPE (buf, IPSEC_ID_IPV6_ADDR); break; } /* Already in network byteorder. */ memcpy (buf + ISAKMP_ID_DATA_OFF, sockaddr_addrdata (src), sockaddr_addrlen (src)); } if (message_add_payload (msg, ISAKMP_PAYLOAD_ID, buf, sz, 1)) { free (buf); return -1; } *id_len = sz - ISAKMP_GEN_SZ; *id = malloc (*id_len); if (!*id) { log_error ("ike_phase_1_send_ID: malloc (%lu) failed", (unsigned long)*id_len); return -1; } memcpy (*id, buf + ISAKMP_GEN_SZ, *id_len); snprintf (header, sizeof header, "ike_phase_1_send_ID: %s", constant_name (ipsec_id_cst, GET_ISAKMP_ID_TYPE (buf))); LOG_DBG_BUF ((LOG_NEGOTIATION, 40, header, buf + ISAKMP_ID_DATA_OFF, sz - ISAKMP_ID_DATA_OFF)); return 0; } int ike_phase_1_send_AUTH (struct message *msg) { struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; if (ie->ike_auth->encode_hash (msg)) { /* XXX Log? */ return -1; } /* * XXX Many people say the COMMIT flag is just junk, especially in Phase 1. */ #ifdef notyet if ((exchange->flags & EXCHANGE_FLAG_COMMITTED) == 0) exchange->flags |= EXCHANGE_FLAG_I_COMMITTED; #endif return 0; } /* Receive ID and HASH and check that the exchange has been consistent. */ int ike_phase_1_recv_ID_AUTH (struct message *msg) { if (ike_phase_1_recv_ID (msg)) return -1; return ike_phase_1_recv_AUTH (msg); } /* Receive ID. */ int ike_phase_1_recv_ID (struct message *msg) { struct exchange *exchange = msg->exchange; struct payload *payload; char header[80], *rs = 0, *rid = 0, *p; int initiator = exchange->initiator; u_int8_t **id, id_type; size_t *id_len, sz; struct sockaddr *sa; payload = TAILQ_FIRST (&msg->payload[ISAKMP_PAYLOAD_ID]); if (exchange->name) rs = conf_get_str (exchange->name, "Remote-ID"); if (rs) { sz = ipsec_id_size (rs, &id_type); if (sz == -1) { log_print ("ike_phase_1_recv_ID: could not handle specified " "Remote-ID [%s]", rs); return -1; } rid = malloc (sz); if (!rid) { log_error ("ike_phase_1_recv_ID: malloc (%lu) failed", (unsigned long)sz); return -1; } switch (id_type) { case IPSEC_ID_IPV4_ADDR: case IPSEC_ID_IPV6_ADDR: p = conf_get_str (rs, "Address"); if (!p) { log_print ("ike_phase_1_recv_ID: " "failed to get Address in Remote-ID section [%s]", rs); free (rid); return -1; } if (text2sockaddr (p, 0, &sa) == -1) { log_print ("ike_phase_1_recv_ID: failed to parse address %s", p); free (rid); return -1; } if ((id_type == IPSEC_ID_IPV4_ADDR && sa->sa_family != AF_INET) || (id_type == IPSEC_ID_IPV6_ADDR && sa->sa_family != AF_INET6)) { log_print ("ike_phase_1_recv_ID: " "address %s not of expected family", p); free (rid); free (sa); return -1; } memcpy (rid, sockaddr_addrdata (sa), sockaddr_addrlen (sa)); free (sa); break; case IPSEC_ID_FQDN: case IPSEC_ID_USER_FQDN: case IPSEC_ID_KEY_ID: p = conf_get_str (rs, "Name"); if (!p) { log_print ("ike_phase_1_recv_ID: " "failed to get Name in Remote-ID section [%s]", rs); free (rid); return -1; } memcpy (rid, p, sz); break; default: log_print ("ike_phase_1_recv_ID: unsupported ID type %d", id_type); free (rid); return -1; } /* Compare expected/desired and received remote ID */ if (bcmp (rid, payload->p + ISAKMP_ID_DATA_OFF, sz)) { free (rid); log_print ("ike_phase_1_recv_ID: " "received remote ID other than expected %s", p); return -1; } free (rid); } /* Choose the right fields to fill in */ id = initiator ? &exchange->id_r : &exchange->id_i; id_len = initiator ? &exchange->id_r_len : &exchange->id_i_len; *id_len = GET_ISAKMP_GEN_LENGTH (payload->p) - ISAKMP_GEN_SZ; *id = malloc (*id_len); if (!*id) { log_error ("ike_phase_1_recv_ID: malloc (%lu) failed", (unsigned long)*id_len); return -1; } memcpy (*id, payload->p + ISAKMP_GEN_SZ, *id_len); snprintf (header, sizeof header, "ike_phase_1_recv_ID: %s", constant_name (ipsec_id_cst, GET_ISAKMP_ID_TYPE (payload->p))); LOG_DBG_BUF ((LOG_NEGOTIATION, 40, header, payload->p + ISAKMP_ID_DATA_OFF, *id_len + ISAKMP_GEN_SZ - ISAKMP_ID_DATA_OFF)); payload->flags |= PL_MARK; return 0; } /* Receive HASH and check that the exchange has been consistent. */ int ike_phase_1_recv_AUTH (struct message *msg) { struct exchange *exchange = msg->exchange; struct ipsec_exch *ie = exchange->data; struct prf *prf; struct hash *hash = ie->hash; char header[80]; size_t hashsize = hash->hashsize; int initiator = exchange->initiator; u_int8_t **hash_p, *id; size_t id_len; /* Choose the right fields to fill in */ hash_p = initiator ? &ie->hash_r : &ie->hash_i; id = initiator ? exchange->id_r : exchange->id_i; id_len = initiator ? exchange->id_r_len : exchange->id_i_len; /* The decoded hash will be in ie->hash_r or ie->hash_i */ if (ie->ike_auth->decode_hash (msg)) { message_drop (msg, ISAKMP_NOTIFY_INVALID_ID_INFORMATION, 0, 1, 0); return -1; } /* Allocate the prf and start calculating his HASH. */ prf = prf_alloc (ie->prf_type, hash->type, ie->skeyid, ie->skeyid_len); if (!prf) { /* XXX Log? */ return -1; } prf->Init (prf->prfctx); prf->Update (prf->prfctx, initiator ? ie->g_xr : ie->g_xi, ie->g_x_len); prf->Update (prf->prfctx, initiator ? ie->g_xi : ie->g_xr, ie->g_x_len); prf->Update (prf->prfctx, exchange->cookies + (initiator ? ISAKMP_HDR_RCOOKIE_OFF : ISAKMP_HDR_ICOOKIE_OFF), ISAKMP_HDR_ICOOKIE_LEN); prf->Update (prf->prfctx, exchange->cookies + (initiator ? ISAKMP_HDR_ICOOKIE_OFF : ISAKMP_HDR_RCOOKIE_OFF), ISAKMP_HDR_ICOOKIE_LEN); prf->Update (prf->prfctx, ie->sa_i_b, ie->sa_i_b_len); prf->Update (prf->prfctx, id, id_len); prf->Final (hash->digest, prf->prfctx); prf_free (prf); snprintf (header, sizeof header, "ike_phase_1_recv_AUTH: computed HASH_%c", initiator ? 'R' : 'I'); LOG_DBG_BUF ((LOG_NEGOTIATION, 80, header, hash->digest, hashsize)); /* Check that the hash we got matches the one we computed. */ if (memcmp (*hash_p, hash->digest, hashsize) != 0) { /* XXX Log? */ return -1; } return 0; } struct attr_node { LIST_ENTRY (attr_node) link; u_int16_t type; }; struct validation_state { struct conf_list_node *xf; LIST_HEAD (attr_head, attr_node) attrs; char *life; }; /* Validate a proposal inside SA according to EXCHANGE's policy. */ static int ike_phase_1_validate_prop (struct exchange *exchange, struct sa *sa, struct sa *isakmp_sa) { struct conf_list *conf, *tags; struct conf_list_node *xf, *tag; struct proto *proto; struct validation_state vs; struct attr_node *node, *next_node; /* Get the list of transforms. */ conf = conf_get_list (exchange->policy, "Transforms"); if (!conf) return 0; for (xf = TAILQ_FIRST (&conf->fields); xf; xf = TAILQ_NEXT (xf, link)) { for (proto = TAILQ_FIRST (&sa->protos); proto; proto = TAILQ_NEXT (proto, link)) { /* Mark all attributes in our policy as unseen. */ LIST_INIT (&vs.attrs); vs.xf = xf; vs.life = 0; if (attribute_map (proto->chosen->p + ISAKMP_TRANSFORM_SA_ATTRS_OFF, GET_ISAKMP_GEN_LENGTH (proto->chosen->p) - ISAKMP_TRANSFORM_SA_ATTRS_OFF, attribute_unacceptable, &vs)) goto try_next; /* Sweep over unseen tags in this section. */ tags = conf_get_tag_list (xf->field); if (tags) { for (tag = TAILQ_FIRST (&tags->fields); tag; tag = TAILQ_NEXT (tag, link)) /* * XXX Should we care about attributes we have, they do not * provide? */ for (node = LIST_FIRST (&vs.attrs); node; node = next_node) { next_node = LIST_NEXT (node, link); if (node->type == constant_value (ike_attr_cst, tag->field)) { LIST_REMOVE (node, link); free (node); } } conf_free_list (tags); } /* Are there leftover tags in this section? */ node = LIST_FIRST (&vs.attrs); if (node) goto try_next; } /* All protocols were OK, we succeeded. */ LOG_DBG ((LOG_NEGOTIATION, 20, "ike_phase_1_validate_prop: success")); conf_free_list (conf); if (vs.life) free (vs.life); return 1; try_next: /* Are there leftover tags in this section? */ node = LIST_FIRST (&vs.attrs); while (node) { LIST_REMOVE (node, link); free (node); node = LIST_FIRST (&vs.attrs); } if (vs.life) free (vs.life); } LOG_DBG ((LOG_NEGOTIATION, 20, "ike_phase_1_validate_prop: failure")); conf_free_list (conf); return 0; } /* * Look at the attribute of type TYPE, located at VALUE for LEN bytes forward. * The VVS argument holds a validation state kept across invocations. * If the attribute is unacceptable to use, return non-zero, otherwise zero. */ static int attribute_unacceptable (u_int16_t type, u_int8_t *value, u_int16_t len, void *vvs) { struct validation_state *vs = vvs; struct conf_list *life_conf; struct conf_list_node *xf = vs->xf, *life; char *tag = constant_lookup (ike_attr_cst, type); char *str; struct constant_map *map; struct attr_node *node; int rv; if (!tag) { LOG_DBG ((LOG_NEGOTIATION, 60, "attribute_unacceptable: attribute type %d not known", type)); return 1; } switch (type) { case IKE_ATTR_ENCRYPTION_ALGORITHM: case IKE_ATTR_HASH_ALGORITHM: case IKE_ATTR_AUTHENTICATION_METHOD: case IKE_ATTR_GROUP_DESCRIPTION: case IKE_ATTR_GROUP_TYPE: case IKE_ATTR_PRF: str = conf_get_str (xf->field, tag); if (!str) { /* This attribute does not exist in this policy. */ LOG_DBG ((LOG_NEGOTIATION, 70, "attribute_unacceptable: attr %s does not exist in %s", tag, xf->field)); return 1; } map = constant_link_lookup (ike_attr_cst, type); if (!map) return 1; if ((constant_value (map, str) == decode_16 (value)) || (!strcmp (str, "ANY"))) { /* Mark this attribute as seen. */ node = malloc (sizeof *node); if (!node) { log_error ("attribute_unacceptable: malloc (%lu) failed", (unsigned long)sizeof *node); return 1; } node->type = type; LIST_INSERT_HEAD (&vs->attrs, node, link); return 0; } LOG_DBG ((LOG_NEGOTIATION, 70, "attribute_unacceptable: %s: got %s, expected %s", tag, constant_name (map, decode_16 (value)), str)); return 1; case IKE_ATTR_GROUP_PRIME: case IKE_ATTR_GROUP_GENERATOR_1: case IKE_ATTR_GROUP_GENERATOR_2: case IKE_ATTR_GROUP_CURVE_A: case IKE_ATTR_GROUP_CURVE_B: /* XXX Bignums not handled yet. */ return 1; case IKE_ATTR_LIFE_TYPE: case IKE_ATTR_LIFE_DURATION: life_conf = conf_get_list (xf->field, "Life"); if (life_conf && !strcmp (conf_get_str (xf->field, "Life"), "ANY")) return 0; rv = 1; if (!life_conf) { /* Life attributes given, but not in our policy. */ LOG_DBG ((LOG_NEGOTIATION, 70, "attribute_unacceptable: " "received unexpected life attribute")); return 1; } /* * Each lifetime type must match, otherwise we turn the proposal down. * In order to do this we need to find the specific section of our * policy's "Life" list and match its duration */ switch (type) { case IKE_ATTR_LIFE_TYPE: for (life = TAILQ_FIRST (&life_conf->fields); life; life = TAILQ_NEXT (life, link)) { str = conf_get_str (life->field, "LIFE_TYPE"); if (!str) { LOG_DBG ((LOG_NEGOTIATION, 70, "attribute_unacceptable: " "section [%s] has no LIFE_TYPE", life->field)); continue; } /* * If this is the type we are looking at, save a pointer * to this section in vs->life. */ if (constant_value (ike_duration_cst, str) == decode_16 (value)) { vs->life = strdup (life->field); rv = 0; goto bail_out; } } LOG_DBG ((LOG_NEGOTIATION, 70, "attribute_unacceptable: unrecognized LIFE_TYPE %d", decode_16 (value))); vs->life = 0; break; case IKE_ATTR_LIFE_DURATION: if (!vs->life) { LOG_DBG ((LOG_NEGOTIATION, 70, "attribute_unacceptable: " "LIFE_DURATION without LIFE_TYPE")); rv = 1; goto bail_out; } str = conf_get_str (vs->life, "LIFE_DURATION"); if (str) { if (!strcmp (str, "ANY")) rv = 0; else rv = !conf_match_num (vs->life, "LIFE_DURATION", len == 4 ? decode_32 (value) : decode_16 (value)); } else { LOG_DBG ((LOG_NEGOTIATION, 70, "attribute_unacceptable: " "section [%s] has no LIFE_DURATION", vs->life)); rv = 1; } free (vs->life); vs->life = 0; break; } bail_out: conf_free_list (life_conf); return rv; case IKE_ATTR_KEY_LENGTH: case IKE_ATTR_FIELD_SIZE: case IKE_ATTR_GROUP_ORDER: if (conf_match_num (xf->field, tag, decode_16 (value))) { /* Mark this attribute as seen. */ node = malloc (sizeof *node); if (!node) { log_error ("attribute_unacceptable: malloc (%lu) failed", (unsigned long)sizeof *node); return 1; } node->type = type; LIST_INSERT_HEAD (&vs->attrs, node, link); return 0; } return 1; } return 1; }