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Impemented basic pseudonym support in EAP-SIM

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This commit is contained in:
Martin Willi
2009-11-12 10:34:00 +01:00
parent f81760dcd1
commit 0328fe940d
2 changed files with 221 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/charon/plugins/eap_sim/eap_sim_peer.c
+117 -13
View File
@@ -43,7 +43,12 @@ struct private_eap_sim_peer_t {
/**
* permanent ID of peer
*/
identification_t *peer;
identification_t *permanent;
/**
* Pseudonym identity the peer uses
*/
identification_t *pseudonym;
/**
* EAP-SIM crypto helper
@@ -77,8 +82,8 @@ static chunk_t version = chunk_from_chars(0x00,0x01);
/**
* Read a triplet from the SIM card
*/
static bool get_card_triplet(private_eap_sim_peer_t *this,
char *rand, char *sres, char *kc)
static bool get_triplet(private_eap_sim_peer_t *this, identification_t *peer,
char *rand, char *sres, char *kc)
{
enumerator_t *enumerator;
sim_card_t *card;
@@ -87,7 +92,7 @@ static bool get_card_triplet(private_eap_sim_peer_t *this,
enumerator = charon->sim->create_card_enumerator(charon->sim);
while (enumerator->enumerate(enumerator, &card))
{
if (card->get_triplet(card, this->peer, rand, sres, kc))
if (card->get_triplet(card, peer, rand, sres, kc))
{
success = TRUE;
break;
@@ -96,11 +101,57 @@ static bool get_card_triplet(private_eap_sim_peer_t *this,
enumerator->destroy(enumerator);
if (!success)
{
DBG1(DBG_IKE, "no SIM card found with triplets for '%Y'", this->peer);
DBG1(DBG_IKE, "no SIM card found with triplets for '%Y'", peer);
}
return success;
}
/**
* Find a stored pseudonym on a SIM card
*/
static identification_t *get_pseudonym(private_eap_sim_peer_t *this)
{
enumerator_t *enumerator;
sim_card_t *card;
identification_t *pseudonym = NULL;
enumerator = charon->sim->create_card_enumerator(charon->sim);
while (enumerator->enumerate(enumerator, &card))
{
pseudonym = card->get_pseudonym(card, this->permanent);
if (pseudonym)
{
DBG1(DBG_IKE, "using stored pseudonym identity '%Y' "
"instead of '%Y'", pseudonym, this->permanent);
break;
}
}
enumerator->destroy(enumerator);
return pseudonym;
}
/**
* Store a pseudonym in a SIM card
*/
static void set_pseudonym(private_eap_sim_peer_t *this, chunk_t data)
{
enumerator_t *enumerator;
sim_card_t *card;
identification_t *pseudonym;
char buf[data.len + 1];
snprintf(buf, sizeof(buf), "%.*s", data.len, data.ptr);
pseudonym = identification_create_from_string(buf);
DBG1(DBG_IKE, "received pseudonym '%Y' for next authentication", pseudonym);
enumerator = charon->sim->create_card_enumerator(charon->sim);
while (enumerator->enumerate(enumerator, &card))
{
card->set_pseudonym(card, this->permanent, pseudonym);
}
enumerator->destroy(enumerator);
pseudonym->destroy(pseudonym);
}
/**
* Create a SIM_CLIENT_ERROR
*/
@@ -132,9 +183,10 @@ static status_t process_start(private_eap_sim_peer_t *this,
simaka_message_t *message;
enumerator_t *enumerator;
simaka_attribute_t type;
chunk_t data;
chunk_t data, id;
rng_t *rng;
bool supported = FALSE;
simaka_attribute_t id_req = 0;
enumerator = in->create_attribute_enumerator(in);
while (enumerator->enumerate(enumerator, &type, &data))
@@ -155,6 +207,11 @@ static status_t process_start(private_eap_sim_peer_t *this,
}
break;
}
case AT_ANY_ID_REQ:
case AT_FULLAUTH_ID_REQ:
case AT_PERMANENT_ID_REQ:
id_req = type;
break;
default:
if (!simaka_attribute_skippable(type))
{
@@ -176,6 +233,26 @@ static status_t process_start(private_eap_sim_peer_t *this,
return NEED_MORE;
}
switch (id_req)
{
case AT_ANY_ID_REQ:
/* TODO: reauth handling */
case AT_FULLAUTH_ID_REQ:
DESTROY_IF(this->pseudonym);
this->pseudonym = get_pseudonym(this);
if (this->pseudonym)
{
id = this->pseudonym->get_encoding(this->pseudonym);
break;
}
/* FALL */
case AT_PERMANENT_ID_REQ:
id = this->permanent->get_encoding(this->permanent);
break;
default:
break;
}
/* generate AT_NONCE_MT value */
rng = this->crypto->get_rng(this->crypto);
free(this->nonce.ptr);
@@ -185,6 +262,10 @@ static status_t process_start(private_eap_sim_peer_t *this,
SIM_START, this->crypto);
message->add_attribute(message, AT_SELECTED_VERSION, version);
message->add_attribute(message, AT_NONCE_MT, this->nonce);
if (id.len)
{
message->add_attribute(message, AT_IDENTITY, id);
}
*out = message->generate(message, chunk_empty);
message->destroy(message);
@@ -201,6 +282,7 @@ static status_t process_challenge(private_eap_sim_peer_t *this,
enumerator_t *enumerator;
simaka_attribute_t type;
chunk_t data, rands = chunk_empty, kcs, kc, sreses, sres;
identification_t *peer;
if (this->tries-- <= 0)
{
@@ -230,6 +312,12 @@ static status_t process_challenge(private_eap_sim_peer_t *this,
}
enumerator->destroy(enumerator);
peer = this->permanent;
if (this->pseudonym)
{
peer = this->pseudonym;
}
/* excepting two or three RAND, each 16 bytes. We require two valid
* and different RANDs */
if ((rands.len != 2 * SIM_RAND_LEN && rands.len != 3 * SIM_RAND_LEN) ||
@@ -245,7 +333,7 @@ static status_t process_challenge(private_eap_sim_peer_t *this,
sreses = sres = chunk_alloca(rands.len / 4);
while (rands.len >= SIM_RAND_LEN)
{
if (!get_card_triplet(this, rands.ptr, sres.ptr, kc.ptr))
if (!get_triplet(this, peer, rands.ptr, sres.ptr, kc.ptr))
{
DBG1(DBG_IKE, "unable to get EAP-SIM triplet");
*out = create_client_error(this, in->get_identifier(in),
@@ -261,17 +349,31 @@ static status_t process_challenge(private_eap_sim_peer_t *this,
data = chunk_cata("cccc", kcs, this->nonce, this->version_list, version);
free(this->msk.ptr);
this->msk = this->crypto->derive_keys_full(this->crypto, this->peer, data);
this->msk = this->crypto->derive_keys_full(this->crypto, peer, data);
/* verify AT_MAC attribute, signature is over "EAP packet | NONCE_MT" */
if (!in->verify(in, this->nonce))
/* Verify AT_MAC attribute, signature is over "EAP packet | NONCE_MT", and
* parse() again after key derivation, reading encrypted attributes */
if (!in->verify(in, this->nonce) || !in->parse(in))
{
DBG1(DBG_IKE, "AT_MAC verification failed");
*out = create_client_error(this, in->get_identifier(in),
SIM_UNABLE_TO_PROCESS);
return NEED_MORE;
}
enumerator = in->create_attribute_enumerator(in);
while (enumerator->enumerate(enumerator, &type, &data))
{
switch (type)
{
case AT_NEXT_PSEUDONYM:
set_pseudonym(this, data);
break;
default:
break;
}
}
enumerator->destroy(enumerator);
/* build response with AT_MAC, built over "EAP packet | n*SRES" */
message = simaka_message_create(FALSE, in->get_identifier(in), EAP_SIM,
SIM_CHALLENGE, this->crypto);
@@ -428,7 +530,8 @@ static bool is_mutual(private_eap_sim_peer_t *this)
*/
static void destroy(private_eap_sim_peer_t *this)
{
this->peer->destroy(this->peer);
this->permanent->destroy(this->permanent);
DESTROY_IF(this->pseudonym);
this->crypto->destroy(this->crypto);
free(this->version_list.ptr);
free(this->nonce.ptr);
@@ -457,7 +560,8 @@ eap_sim_peer_t *eap_sim_peer_create(identification_t *server,
free(this);
return NULL;
}
this->peer = peer->clone(peer);
this->permanent = peer->clone(peer);
this->pseudonym = NULL;
this->tries = MAX_TRIES;
this->version_list = chunk_empty;
this->nonce = chunk_empty;
src/charon/plugins/eap_sim/eap_sim_server.c
+104 -11
View File
@@ -38,7 +38,7 @@ struct private_eap_sim_server_t {
/**
* permanent ID of peer
*/
identification_t *peer;
identification_t *permanent;
/**
* EAP-SIM/AKA crypto helper
@@ -60,6 +60,21 @@ struct private_eap_sim_server_t {
*/
chunk_t msk;
/**
* Do we request fast reauthentication?
*/
bool use_reauth;
/**
* Do we request pseudonym identities?
*/
bool use_pseudonym;
/**
* Do we request permanent identities?
*/
bool use_permanent;
/**
* EAP-SIM message we have initiated
*/
@@ -72,8 +87,8 @@ static chunk_t version = chunk_from_chars(0x00,0x01);
/**
* Fetch a triplet from a provider
*/
static bool get_provider_triplet(private_eap_sim_server_t *this,
char *rand, char *sres, char *kc)
static bool get_triplet(private_eap_sim_server_t *this, identification_t *peer,
char *rand, char *sres, char *kc)
{
enumerator_t *enumerator;
sim_provider_t *provider;
@@ -82,7 +97,7 @@ static bool get_provider_triplet(private_eap_sim_server_t *this,
enumerator = charon->sim->create_provider_enumerator(charon->sim);
while (enumerator->enumerate(enumerator, &provider))
{
if (provider->get_triplet(provider, this->peer, rand, sres, kc))
if (provider->get_triplet(provider, peer, rand, sres, kc))
{
enumerator->destroy(enumerator);
return TRUE;
@@ -91,10 +106,32 @@ static bool get_provider_triplet(private_eap_sim_server_t *this,
}
enumerator->destroy(enumerator);
DBG1(DBG_IKE, "tried %d SIM providers, but none had a triplet for '%Y'",
tried, this->peer);
tried, peer);
return FALSE;
}
/**
* Generate a new pseudonym for next authentication
*/
static identification_t* gen_pseudonym(private_eap_sim_server_t *this)
{
enumerator_t *enumerator;
sim_provider_t *provider;
identification_t *pseudonym = NULL;
enumerator = charon->sim->create_provider_enumerator(charon->sim);
while (enumerator->enumerate(enumerator, &provider))
{
pseudonym = provider->gen_pseudonym(provider, this->permanent);
if (pseudonym)
{
break;
}
}
enumerator->destroy(enumerator);
return pseudonym;
}
/**
* process an EAP-SIM/Response/Start message
*/
@@ -104,8 +141,10 @@ static status_t process_start(private_eap_sim_server_t *this,
simaka_message_t *message;
enumerator_t *enumerator;
simaka_attribute_t type;
chunk_t data, rands, rand, kcs, kc, sreses, sres, nonce = chunk_empty;
chunk_t data, id = chunk_empty, nonce = chunk_empty;
chunk_t rands, rand, kcs, kc, sreses, sres;
bool supported = FALSE;
identification_t *peer = NULL, *pseudonym;
int i;
if (this->pending != SIM_START)
@@ -129,6 +168,9 @@ static status_t process_start(private_eap_sim_server_t *this,
supported = TRUE;
}
break;
case AT_IDENTITY:
id = data;
break;
default:
if (!simaka_attribute_skippable(type))
{
@@ -146,6 +188,26 @@ static status_t process_start(private_eap_sim_server_t *this,
return FAILED;
}
if (id.len)
{
if (this->use_reauth)
{
/* TODO: handle reauthentication identity */
}
if (this->use_pseudonym || this->use_permanent)
{
char buf[id.len + 1];
snprintf(buf, sizeof(buf), "%.*s", id.len, id.ptr);
peer = identification_create_from_string(buf);
DBG1(DBG_CFG, "received (pseudonym) identity '%Y'", peer);
}
}
if (!peer)
{
peer = this->permanent->clone(this->permanent);
}
/* read triplets from provider */
rand = rands = chunk_alloca(SIM_RAND_LEN * TRIPLET_COUNT);
kc = kcs = chunk_alloca(SIM_KC_LEN * TRIPLET_COUNT);
@@ -153,9 +215,9 @@ static status_t process_start(private_eap_sim_server_t *this,
rands.len = kcs.len = sreses.len = 0;
for (i = 0; i < TRIPLET_COUNT; i++)
{
if (!get_provider_triplet(this, rand.ptr, sres.ptr, kc.ptr))
if (!get_triplet(this, peer, rand.ptr, sres.ptr, kc.ptr))
{
DBG1(DBG_IKE, "getting EAP-SIM triplet %d failed", i);
peer->destroy(peer);
return FAILED;
}
rands.len += SIM_RAND_LEN;
@@ -170,12 +232,25 @@ static status_t process_start(private_eap_sim_server_t *this,
data = chunk_cata("cccc", kcs, nonce, version, version);
free(this->msk.ptr);
this->msk = this->crypto->derive_keys_full(this->crypto, this->peer, data);
this->msk = this->crypto->derive_keys_full(this->crypto, peer, data);
peer->destroy(peer);
/* build response with AT_MAC, built over "EAP packet | NONCE_MT" */
message = simaka_message_create(TRUE, this->identifier++, EAP_SIM,
SIM_CHALLENGE, this->crypto);
message->add_attribute(message, AT_RAND, rands);
if (this->use_pseudonym)
{
/* generate new pseudonym for next authentication */
pseudonym = gen_pseudonym(this);
if (peer)
{
DBG1(DBG_IKE, "proposing new pseudonym '%Y'", pseudonym);
message->add_attribute(message, AT_NEXT_PSEUDONYM,
pseudonym->get_encoding(pseudonym));
pseudonym->destroy(pseudonym);
}
}
*out = message->generate(message, nonce);
message->destroy(message);
@@ -300,6 +375,18 @@ static status_t initiate(private_eap_sim_server_t *this, eap_payload_t **out)
message = simaka_message_create(TRUE, this->identifier++, EAP_SIM,
SIM_START, this->crypto);
message->add_attribute(message, AT_VERSION_LIST, version);
if (this->use_reauth)
{
message->add_attribute(message, AT_ANY_ID_REQ, chunk_empty);
}
else if (this->use_pseudonym)
{
message->add_attribute(message, AT_FULLAUTH_ID_REQ, chunk_empty);
}
else if (this->use_permanent)
{
message->add_attribute(message, AT_PERMANENT_ID_REQ, chunk_empty);
}
*out = message->generate(message, chunk_empty);
message->destroy(message);
@@ -343,7 +430,7 @@ static bool is_mutual(private_eap_sim_server_t *this)
static void destroy(private_eap_sim_server_t *this)
{
this->crypto->destroy(this->crypto);
this->peer->destroy(this->peer);
this->permanent->destroy(this->permanent);
free(this->sreses.ptr);
free(this->msk.ptr);
free(this);
@@ -370,10 +457,16 @@ eap_sim_server_t *eap_sim_server_create(identification_t *server,
free(this);
return NULL;
}
this->peer = peer->clone(peer);
this->permanent = peer->clone(peer);
this->sreses = chunk_empty;
this->msk = chunk_empty;
this->pending = 0;
this->use_reauth = lib->settings->get_bool(lib->settings,
"charon.plugins.eap-sim.use_reauth", TRUE);
this->use_pseudonym = lib->settings->get_bool(lib->settings,
"charon.plugins.eap-sim.use_pseudonym", TRUE);
this->use_permanent = lib->settings->get_bool(lib->settings,
"charon.plugins.eap-sim.use_permanent", TRUE);
/* generate a non-zero identifier */
do {
this->identifier = random();