diff options
Diffstat (limited to 'src/libcharon/sa/ikev1/phase1.c')
-rw-r--r-- | src/libcharon/sa/ikev1/phase1.c | 795 |
1 files changed, 795 insertions, 0 deletions
diff --git a/src/libcharon/sa/ikev1/phase1.c b/src/libcharon/sa/ikev1/phase1.c new file mode 100644 index 000000000..1189d3c69 --- /dev/null +++ b/src/libcharon/sa/ikev1/phase1.c @@ -0,0 +1,795 @@ +/* + * Copyright (C) 2012 Tobias Brunner + * Hochschule fuer Technik Rapperswil + * + * Copyright (C) 2012 Martin Willi + * Copyright (C) 2012 revosec AG + * + * 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 <http://www.fsf.org/copyleft/gpl.txt>. + * + * 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 "phase1.h" + +#include <daemon.h> +#include <sa/ikev1/keymat_v1.h> +#include <encoding/payloads/ke_payload.h> +#include <encoding/payloads/nonce_payload.h> +#include <collections/linked_list.h> + +typedef struct private_phase1_t private_phase1_t; + +/** + * Private data of an phase1_t object. + */ +struct private_phase1_t { + + /** + * Public phase1_t interface. + */ + phase1_t public; + + /** + * IKE_SA we negotiate + */ + ike_sa_t *ike_sa; + + /** + * Currently selected peer config + */ + peer_cfg_t *peer_cfg; + + /** + * Other possible peer config candidates + */ + linked_list_t *candidates; + + /** + * Acting as initiator + */ + bool initiator; + + /** + * Extracted SA payload bytes + */ + chunk_t sa_payload; + + /** + * DH exchange + */ + diffie_hellman_t *dh; + + /** + * Keymat derivation (from SA) + */ + keymat_v1_t *keymat; + + /** + * Received public DH value from peer + */ + chunk_t dh_value; + + /** + * Initiators nonce + */ + chunk_t nonce_i; + + /** + * Responder nonce + */ + chunk_t nonce_r; +}; + +/** + * Get the first authentcation config from peer config + */ +static auth_cfg_t *get_auth_cfg(peer_cfg_t *peer_cfg, bool local) +{ + enumerator_t *enumerator; + auth_cfg_t *cfg = NULL; + + enumerator = peer_cfg->create_auth_cfg_enumerator(peer_cfg, local); + enumerator->enumerate(enumerator, &cfg); + enumerator->destroy(enumerator); + return cfg; +} + +/** + * Lookup a shared secret for this IKE_SA + */ +static shared_key_t *lookup_shared_key(private_phase1_t *this, + peer_cfg_t *peer_cfg) +{ + host_t *me, *other; + identification_t *my_id, *other_id; + shared_key_t *shared_key = NULL; + auth_cfg_t *my_auth, *other_auth; + enumerator_t *enumerator; + + /* try to get a PSK for IP addresses */ + me = this->ike_sa->get_my_host(this->ike_sa); + other = this->ike_sa->get_other_host(this->ike_sa); + my_id = identification_create_from_sockaddr(me->get_sockaddr(me)); + other_id = identification_create_from_sockaddr(other->get_sockaddr(other)); + if (my_id && other_id) + { + shared_key = lib->credmgr->get_shared(lib->credmgr, SHARED_IKE, + my_id, other_id); + } + DESTROY_IF(my_id); + DESTROY_IF(other_id); + if (shared_key) + { + return shared_key; + } + + if (peer_cfg) + { /* as initiator or aggressive responder, use identities */ + my_auth = get_auth_cfg(peer_cfg, TRUE); + other_auth = get_auth_cfg(peer_cfg, FALSE); + if (my_auth && other_auth) + { + my_id = my_auth->get(my_auth, AUTH_RULE_IDENTITY); + if (peer_cfg->use_aggressive(peer_cfg)) + { + other_id = this->ike_sa->get_other_id(this->ike_sa); + } + else + { + other_id = other_auth->get(other_auth, AUTH_RULE_IDENTITY); + } + if (my_id && other_id) + { + shared_key = lib->credmgr->get_shared(lib->credmgr, SHARED_IKE, + my_id, other_id); + if (!shared_key) + { + DBG1(DBG_IKE, "no shared key found for '%Y'[%H] - '%Y'[%H]", + my_id, me, other_id, other); + } + } + } + return shared_key; + } + /* as responder, we try to find a config by IP */ + enumerator = charon->backends->create_peer_cfg_enumerator(charon->backends, + me, other, NULL, NULL, IKEV1); + while (enumerator->enumerate(enumerator, &peer_cfg)) + { + my_auth = get_auth_cfg(peer_cfg, TRUE); + other_auth = get_auth_cfg(peer_cfg, FALSE); + if (my_auth && other_auth) + { + my_id = my_auth->get(my_auth, AUTH_RULE_IDENTITY); + other_id = other_auth->get(other_auth, AUTH_RULE_IDENTITY); + if (my_id) + { + shared_key = lib->credmgr->get_shared(lib->credmgr, SHARED_IKE, + my_id, other_id); + if (shared_key) + { + break; + } + else + { + DBG1(DBG_IKE, "no shared key found for '%Y'[%H] - '%Y'[%H]", + my_id, me, other_id, other); + } + } + } + } + enumerator->destroy(enumerator); + if (!shared_key) + { + DBG1(DBG_IKE, "no shared key found for %H - %H", me, other); + } + return shared_key; +} + +METHOD(phase1_t, create_hasher, bool, + private_phase1_t *this) +{ + return this->keymat->create_hasher(this->keymat, + this->ike_sa->get_proposal(this->ike_sa)); +} + +METHOD(phase1_t, create_dh, bool, + private_phase1_t *this, diffie_hellman_group_t group) +{ + this->dh = this->keymat->keymat.create_dh(&this->keymat->keymat, group); + return this->dh != NULL; +} + +METHOD(phase1_t, derive_keys, bool, + private_phase1_t *this, peer_cfg_t *peer_cfg, auth_method_t method) +{ + shared_key_t *shared_key = NULL; + + switch (method) + { + case AUTH_PSK: + case AUTH_XAUTH_INIT_PSK: + case AUTH_XAUTH_RESP_PSK: + shared_key = lookup_shared_key(this, peer_cfg); + if (!shared_key) + { + return FALSE; + } + break; + default: + break; + } + + if (!this->keymat->derive_ike_keys(this->keymat, + this->ike_sa->get_proposal(this->ike_sa), + this->dh, this->dh_value, this->nonce_i, this->nonce_r, + this->ike_sa->get_id(this->ike_sa), method, shared_key)) + { + DESTROY_IF(shared_key); + DBG1(DBG_IKE, "key derivation for %N failed", auth_method_names, method); + return FALSE; + } + charon->bus->ike_keys(charon->bus, this->ike_sa, this->dh, this->dh_value, + this->nonce_i, this->nonce_r, NULL, shared_key); + DESTROY_IF(shared_key); + return TRUE; +} + +/** + * Check if a peer skipped authentication by using Hybrid authentication + */ +static bool skipped_auth(private_phase1_t *this, + auth_method_t method, bool local) +{ + bool initiator; + + initiator = local == this->initiator; + if (initiator && method == AUTH_HYBRID_INIT_RSA) + { + return TRUE; + } + if (!initiator && method == AUTH_HYBRID_RESP_RSA) + { + return TRUE; + } + return FALSE; +} + +/** + * Check if remote authentication constraints fulfilled + */ +static bool check_constraints(private_phase1_t *this, auth_method_t method) +{ + identification_t *id; + auth_cfg_t *auth, *cfg; + peer_cfg_t *peer_cfg; + + auth = this->ike_sa->get_auth_cfg(this->ike_sa, FALSE); + /* auth identity to comply */ + id = this->ike_sa->get_other_id(this->ike_sa); + auth->add(auth, AUTH_RULE_IDENTITY, id->clone(id)); + if (skipped_auth(this, method, FALSE)) + { + return TRUE; + } + peer_cfg = this->ike_sa->get_peer_cfg(this->ike_sa); + cfg = get_auth_cfg(peer_cfg, FALSE); + return cfg && auth->complies(auth, cfg, TRUE); +} + +/** + * Save authentication information after authentication succeeded + */ +static void save_auth_cfg(private_phase1_t *this, + auth_method_t method, bool local) +{ + auth_cfg_t *auth; + + if (skipped_auth(this, method, local)) + { + return; + } + auth = auth_cfg_create(); + /* for local config, we _copy_ entires from the config, as it contains + * certificates we must send later. */ + auth->merge(auth, this->ike_sa->get_auth_cfg(this->ike_sa, local), local); + this->ike_sa->add_auth_cfg(this->ike_sa, local, auth); +} + +/** + * Create an authenticator instance + */ +static authenticator_t* create_authenticator(private_phase1_t *this, + auth_method_t method, chunk_t id) +{ + authenticator_t *authenticator; + + authenticator = authenticator_create_v1(this->ike_sa, this->initiator, + method, this->dh, this->dh_value, this->sa_payload, id); + if (!authenticator) + { + DBG1(DBG_IKE, "negotiated authentication method %N not supported", + auth_method_names, method); + } + return authenticator; +} + +METHOD(phase1_t, verify_auth, bool, + private_phase1_t *this, auth_method_t method, message_t *message, + chunk_t id_data) +{ + authenticator_t *authenticator; + status_t status; + + authenticator = create_authenticator(this, method, id_data); + if (authenticator) + { + status = authenticator->process(authenticator, message); + authenticator->destroy(authenticator); + if (status == SUCCESS && check_constraints(this, method)) + { + save_auth_cfg(this, method, FALSE); + return TRUE; + } + } + return FALSE; +} + +METHOD(phase1_t, build_auth, bool, + private_phase1_t *this, auth_method_t method, message_t *message, + chunk_t id_data) +{ + authenticator_t *authenticator; + status_t status; + + authenticator = create_authenticator(this, method, id_data); + if (authenticator) + { + status = authenticator->build(authenticator, message); + authenticator->destroy(authenticator); + if (status == SUCCESS) + { + save_auth_cfg(this, method, TRUE); + return TRUE; + } + } + return FALSE; +} + +/** + * Get the two auth classes from local or remote config + */ +static void get_auth_class(peer_cfg_t *peer_cfg, bool local, + auth_class_t *c1, auth_class_t *c2) +{ + enumerator_t *enumerator; + auth_cfg_t *auth; + + *c1 = *c2 = AUTH_CLASS_ANY; + + enumerator = peer_cfg->create_auth_cfg_enumerator(peer_cfg, local); + while (enumerator->enumerate(enumerator, &auth)) + { + if (*c1 == AUTH_CLASS_ANY) + { + *c1 = (uintptr_t)auth->get(auth, AUTH_RULE_AUTH_CLASS); + } + else + { + *c2 = (uintptr_t)auth->get(auth, AUTH_RULE_AUTH_CLASS); + break; + } + } + enumerator->destroy(enumerator); +} + +/** + * Select an auth method to use by checking what key we have + */ +static auth_method_t get_pubkey_method(private_phase1_t *this, auth_cfg_t *auth) +{ + auth_method_t method = AUTH_NONE; + identification_t *id; + private_key_t *private; + + if (auth) + { + id = (identification_t*)auth->get(auth, AUTH_RULE_IDENTITY); + if (id) + { + private = lib->credmgr->get_private(lib->credmgr, KEY_ANY, id, NULL); + if (private) + { + switch (private->get_type(private)) + { + case KEY_RSA: + method = AUTH_RSA; + break; + case KEY_ECDSA: + switch (private->get_keysize(private)) + { + case 256: + method = AUTH_ECDSA_256; + break; + case 384: + method = AUTH_ECDSA_384; + break; + case 521: + method = AUTH_ECDSA_521; + break; + default: + DBG1(DBG_IKE, "%d bit ECDSA private key size not " + "supported", private->get_keysize(private)); + break; + } + break; + default: + DBG1(DBG_IKE, "private key of type %N not supported", + key_type_names, private->get_type(private)); + break; + } + private->destroy(private); + } + else + { + DBG1(DBG_IKE, "no private key found for '%Y'", id); + } + } + } + return method; +} + +/** + * Calculate authentication method from a peer config + */ +static auth_method_t calc_auth_method(private_phase1_t *this, + peer_cfg_t *peer_cfg) +{ + auth_class_t i1, i2, r1, r2; + + get_auth_class(peer_cfg, this->initiator, &i1, &i2); + get_auth_class(peer_cfg, !this->initiator, &r1, &r2); + + if (i1 == AUTH_CLASS_PUBKEY && r1 == AUTH_CLASS_PUBKEY) + { + if (i2 == AUTH_CLASS_ANY && r2 == AUTH_CLASS_ANY) + { + /* for any pubkey method, return RSA */ + return AUTH_RSA; + } + if (i2 == AUTH_CLASS_XAUTH) + { + return AUTH_XAUTH_INIT_RSA; + } + if (r2 == AUTH_CLASS_XAUTH) + { + return AUTH_XAUTH_RESP_RSA; + } + } + if (i1 == AUTH_CLASS_PSK && r1 == AUTH_CLASS_PSK) + { + if (i2 == AUTH_CLASS_ANY && r2 == AUTH_CLASS_ANY) + { + return AUTH_PSK; + } + if (i2 == AUTH_CLASS_XAUTH) + { + return AUTH_XAUTH_INIT_PSK; + } + if (r2 == AUTH_CLASS_XAUTH) + { + return AUTH_XAUTH_RESP_PSK; + } + } + if (i1 == AUTH_CLASS_XAUTH && r1 == AUTH_CLASS_PUBKEY && + i2 == AUTH_CLASS_ANY && r2 == AUTH_CLASS_ANY) + { + return AUTH_HYBRID_INIT_RSA; + } + return AUTH_NONE; +} + +METHOD(phase1_t, get_auth_method, auth_method_t, + private_phase1_t *this, peer_cfg_t *peer_cfg) +{ + auth_method_t method; + + method = calc_auth_method(this, peer_cfg); + if (method == AUTH_RSA) + { + return get_pubkey_method(this, get_auth_cfg(peer_cfg, TRUE)); + } + return method; +} + +/** + * Check if a peer config can be used with a given auth method + */ +static bool check_auth_method(private_phase1_t *this, peer_cfg_t *peer_cfg, + auth_method_t given) +{ + auth_method_t method; + + method = calc_auth_method(this, peer_cfg); + switch (given) + { + case AUTH_ECDSA_256: + case AUTH_ECDSA_384: + case AUTH_ECDSA_521: + return method == AUTH_RSA; + default: + return method == given; + } +} + +METHOD(phase1_t, select_config, peer_cfg_t*, + private_phase1_t *this, auth_method_t method, bool aggressive, + identification_t *id) +{ + enumerator_t *enumerator; + peer_cfg_t *current; + host_t *me, *other; + + if (this->peer_cfg) + { /* try to find an alternative config */ + if (this->candidates->remove_first(this->candidates, + (void**)¤t) != SUCCESS) + { + DBG1(DBG_CFG, "no alternative config found"); + return NULL; + } + DBG1(DBG_CFG, "switching to peer config '%s'", + current->get_name(current)); + return current; + } + + me = this->ike_sa->get_my_host(this->ike_sa); + other = this->ike_sa->get_other_host(this->ike_sa); + DBG1(DBG_CFG, "looking for %N peer configs matching %H...%H[%Y]", + auth_method_names, method, me, other, id); + enumerator = charon->backends->create_peer_cfg_enumerator(charon->backends, + me, other, NULL, id, IKEV1); + while (enumerator->enumerate(enumerator, ¤t)) + { + if (check_auth_method(this, current, method) && + current->use_aggressive(current) == aggressive) + { + current->get_ref(current); + if (!this->peer_cfg) + { + this->peer_cfg = current; + } + else + { + this->candidates->insert_last(this->candidates, current); + } + } + } + enumerator->destroy(enumerator); + + if (this->peer_cfg) + { + DBG1(DBG_CFG, "selected peer config \"%s\"", + this->peer_cfg->get_name(this->peer_cfg)); + return this->peer_cfg->get_ref(this->peer_cfg); + } + DBG1(DBG_IKE, "no peer config found"); + return NULL; +} + +METHOD(phase1_t, get_id, identification_t*, + private_phase1_t *this, peer_cfg_t *peer_cfg, bool local) +{ + identification_t *id = NULL; + auth_cfg_t *auth; + + auth = get_auth_cfg(peer_cfg, local); + if (auth) + { + id = auth->get(auth, AUTH_RULE_IDENTITY); + if (local && (!id || id->get_type(id) == ID_ANY)) + { /* no ID configured, use local IP address */ + host_t *me; + + me = this->ike_sa->get_my_host(this->ike_sa); + if (!me->is_anyaddr(me)) + { + id = identification_create_from_sockaddr(me->get_sockaddr(me)); + auth->add(auth, AUTH_RULE_IDENTITY, id); + } + } + } + return id; +} + +METHOD(phase1_t, has_virtual_ip, bool, + private_phase1_t *this, peer_cfg_t *peer_cfg) +{ + enumerator_t *enumerator; + bool found = FALSE; + host_t *host; + + enumerator = peer_cfg->create_virtual_ip_enumerator(peer_cfg); + found = enumerator->enumerate(enumerator, &host); + enumerator->destroy(enumerator); + + return found; +} + +METHOD(phase1_t, has_pool, bool, + private_phase1_t *this, peer_cfg_t *peer_cfg) +{ + enumerator_t *enumerator; + bool found = FALSE; + char *pool; + + enumerator = peer_cfg->create_pool_enumerator(peer_cfg); + found = enumerator->enumerate(enumerator, &pool); + enumerator->destroy(enumerator); + + return found; +} + +METHOD(phase1_t, save_sa_payload, bool, + private_phase1_t *this, message_t *message) +{ + enumerator_t *enumerator; + payload_t *payload, *sa = NULL; + chunk_t data; + size_t offset = IKE_HEADER_LENGTH; + + enumerator = message->create_payload_enumerator(message); + while (enumerator->enumerate(enumerator, &payload)) + { + if (payload->get_type(payload) == SECURITY_ASSOCIATION_V1) + { + sa = payload; + break; + } + else + { + offset += payload->get_length(payload); + } + } + enumerator->destroy(enumerator); + + data = message->get_packet_data(message); + if (sa && data.len >= offset + sa->get_length(sa)) + { + /* Get SA payload without 4 byte fixed header */ + data = chunk_skip(data, offset); + data.len = sa->get_length(sa); + data = chunk_skip(data, 4); + this->sa_payload = chunk_clone(data); + return TRUE; + } + DBG1(DBG_IKE, "unable to extract SA payload encoding"); + return FALSE; +} + +METHOD(phase1_t, add_nonce_ke, bool, + private_phase1_t *this, message_t *message) +{ + nonce_payload_t *nonce_payload; + ke_payload_t *ke_payload; + nonce_gen_t *nonceg; + chunk_t nonce; + + ke_payload = ke_payload_create_from_diffie_hellman(KEY_EXCHANGE_V1, this->dh); + message->add_payload(message, &ke_payload->payload_interface); + + nonceg = this->keymat->keymat.create_nonce_gen(&this->keymat->keymat); + if (!nonceg) + { + DBG1(DBG_IKE, "no nonce generator found to create nonce"); + return FALSE; + } + if (!nonceg->allocate_nonce(nonceg, NONCE_SIZE, &nonce)) + { + DBG1(DBG_IKE, "nonce allocation failed"); + nonceg->destroy(nonceg); + return FALSE; + } + nonceg->destroy(nonceg); + + nonce_payload = nonce_payload_create(NONCE_V1); + nonce_payload->set_nonce(nonce_payload, nonce); + message->add_payload(message, &nonce_payload->payload_interface); + + if (this->initiator) + { + this->nonce_i = nonce; + } + else + { + this->nonce_r = nonce; + } + return TRUE; +} + +METHOD(phase1_t, get_nonce_ke, bool, + private_phase1_t *this, message_t *message) +{ + nonce_payload_t *nonce_payload; + ke_payload_t *ke_payload; + + ke_payload = (ke_payload_t*)message->get_payload(message, KEY_EXCHANGE_V1); + if (!ke_payload) + { + DBG1(DBG_IKE, "KE payload missing in message"); + return FALSE; + } + this->dh_value = chunk_clone(ke_payload->get_key_exchange_data(ke_payload)); + this->dh->set_other_public_value(this->dh, this->dh_value); + + nonce_payload = (nonce_payload_t*)message->get_payload(message, NONCE_V1); + if (!nonce_payload) + { + DBG1(DBG_IKE, "NONCE payload missing in message"); + return FALSE; + } + + if (this->initiator) + { + this->nonce_r = nonce_payload->get_nonce(nonce_payload); + } + else + { + this->nonce_i = nonce_payload->get_nonce(nonce_payload); + } + return TRUE; +} + +METHOD(phase1_t, destroy, void, + private_phase1_t *this) +{ + DESTROY_IF(this->peer_cfg); + this->candidates->destroy_offset(this->candidates, + offsetof(peer_cfg_t, destroy)); + chunk_free(&this->sa_payload); + DESTROY_IF(this->dh); + free(this->dh_value.ptr); + free(this->nonce_i.ptr); + free(this->nonce_r.ptr); + free(this); +} + +/** + * See header + */ +phase1_t *phase1_create(ike_sa_t *ike_sa, bool initiator) +{ + private_phase1_t *this; + + INIT(this, + .public = { + .create_hasher = _create_hasher, + .create_dh = _create_dh, + .derive_keys = _derive_keys, + .get_auth_method = _get_auth_method, + .get_id = _get_id, + .select_config = _select_config, + .has_virtual_ip = _has_virtual_ip, + .has_pool = _has_pool, + .verify_auth = _verify_auth, + .build_auth = _build_auth, + .save_sa_payload = _save_sa_payload, + .add_nonce_ke = _add_nonce_ke, + .get_nonce_ke = _get_nonce_ke, + .destroy = _destroy, + }, + .candidates = linked_list_create(), + .ike_sa = ike_sa, + .initiator = initiator, + .keymat = (keymat_v1_t*)ike_sa->get_keymat(ike_sa), + ); + + return &this->public; +} |