Use the EAP-SIM/AKA crypto helper in EAP-SIM
[strongswan.git] / src / charon / plugins / eap_sim / eap_sim_server.c
index 9b9bc9d..4772610 100644 (file)
 #include <daemon.h>
 
 #include <simaka_message.h>
 #include <daemon.h>
 
 #include <simaka_message.h>
+#include <simaka_crypto.h>
 
 /* number of triplets for one authentication */
 #define TRIPLET_COUNT 3
 
 
 /* number of triplets for one authentication */
 #define TRIPLET_COUNT 3
 
-/** length of the AT_NONCE_MT/AT_NONCE_S nonce value */
-#define NONCE_LEN 16
 /** length of the AT_MAC value */
 #define MAC_LEN 16
 /** length of the AT_RAND value */
 /** length of the AT_MAC value */
 #define MAC_LEN 16
 /** length of the AT_RAND value */
 #define KC_LEN 8
 /** length of SRES */
 #define SRES_LEN 4
 #define KC_LEN 8
 /** length of SRES */
 #define SRES_LEN 4
-/** length of the k_encr key */
-#define KENCR_LEN 16
-/** length of the k_auth key */
-#define KAUTH_LEN 16
-/** length of the MSK */
-#define MSK_LEN 64
-/** length of the EMSK */
-#define EMSK_LEN 64
 
 typedef struct private_eap_sim_server_t private_eap_sim_server_t;
 
 
 typedef struct private_eap_sim_server_t private_eap_sim_server_t;
 
@@ -59,29 +50,9 @@ struct private_eap_sim_server_t {
        identification_t *peer;
 
        /**
        identification_t *peer;
 
        /**
-        * Random number generator for nonce, IVs
+        * EAP-SIM/AKA crypto helper
         */
         */
-       rng_t *rng;
-
-       /**
-        * hashing function
-        */
-       hasher_t *hasher;
-
-       /**
-        * prf
-        */
-       prf_t *prf;
-
-       /**
-        * MAC function
-        */
-       signer_t *signer;
-
-       /**
-        * encryption function
-        */
-       crypter_t *crypter;
+       simaka_crypto_t *crypto;
 
        /**
         * unique EAP identifier
 
        /**
         * unique EAP identifier
@@ -99,6 +70,9 @@ struct private_eap_sim_server_t {
        chunk_t msk;
 };
 
        chunk_t msk;
 };
 
+/* version of SIM protocol we speak */
+static chunk_t version = chunk_from_chars(0x00,0x01);
+
 /**
  * Fetch a triplet from a provider
  */
 /**
  * Fetch a triplet from a provider
  */
@@ -126,44 +100,6 @@ static bool get_provider_triplet(private_eap_sim_server_t *this,
 }
 
 /**
 }
 
 /**
- * Derive EAP keys from kc when using full authentication
- */
-static void derive_keys_full(private_eap_sim_server_t *this,
-                                                        chunk_t kcs, chunk_t nonce)
-{
-       char mk[HASH_SIZE_SHA1], k_encr[KENCR_LEN], k_auth[KAUTH_LEN];
-       chunk_t tmp;
-       int i;
-
-       /* MK = SHA1(Identity|n*Kc|NONCE_MT|Version List|Selected Version) */
-       tmp = chunk_cata("ccccc", this->peer->get_encoding(this->peer),
-                                        kcs, nonce, version, version);
-       this->hasher->get_hash(this->hasher, tmp, mk);
-       DBG3(DBG_IKE, "MK = SHA1(%B\n) = %b", &tmp, mk, HASH_SIZE_SHA1);
-
-       /* K_encr | K_auth | MSK | EMSK = prf() | prf() | prf() | prf()
-        * We currently don't need EMSK, so three prf() are sufficient */
-       this->prf->set_key(this->prf, chunk_create(mk, HASH_SIZE_SHA1));
-       tmp = chunk_alloca(this->prf->get_block_size(this->prf) * 3);
-       for (i = 0; i < 3; i++)
-       {
-               this->prf->get_bytes(this->prf, chunk_empty, tmp.ptr + tmp.len / 3 * i);
-       }
-       memcpy(k_encr, tmp.ptr, KENCR_LEN);
-       tmp = chunk_skip(tmp, KENCR_LEN);
-       memcpy(k_auth, tmp.ptr, KAUTH_LEN);
-       tmp = chunk_skip(tmp, KAUTH_LEN);
-       free(this->msk.ptr);
-       this->msk = chunk_alloc(MSK_LEN);
-       memcpy(this->msk.ptr, tmp.ptr, MSK_LEN);
-       DBG3(DBG_IKE, "K_encr %b\nK_auth %b\nMSK %B",
-                k_encr, KENCR_LEN, k_auth, KAUTH_LEN, &this->msk);
-
-       this->signer->set_key(this->signer, chunk_create(k_auth, KAUTH_LEN));
-       this->crypter->set_key(this->crypter, chunk_create(k_encr, KENCR_LEN));
-}
-
-/**
  * process an EAP-SIM/Response/Start message
  */
 static status_t process_start(private_eap_sim_server_t *this,
  * process an EAP-SIM/Response/Start message
  */
 static status_t process_start(private_eap_sim_server_t *this,
@@ -226,13 +162,15 @@ static status_t process_start(private_eap_sim_server_t *this,
        free(this->sreses.ptr);
        this->sreses = chunk_clone(sreses);
 
        free(this->sreses.ptr);
        this->sreses = chunk_clone(sreses);
 
-       derive_keys_full(this, kcs, nonce);
+       data = chunk_cata("cccc", kcs, nonce, version, version);
+       free(this->msk.ptr);
+       this->msk = this->crypto->derive_keys_full(this->crypto, this->peer, data);
 
        /* build response with AT_MAC, built over "EAP packet | NONCE_MT" */
        message = simaka_message_create(TRUE, this->identifier++,
                                                                        EAP_SIM, SIM_CHALLENGE);
        message->add_attribute(message, AT_RAND, rands);
 
        /* build response with AT_MAC, built over "EAP packet | NONCE_MT" */
        message = simaka_message_create(TRUE, this->identifier++,
                                                                        EAP_SIM, SIM_CHALLENGE);
        message->add_attribute(message, AT_RAND, rands);
-       *out = message->generate(message, NULL, NULL, this->signer, nonce);
+       *out = message->generate(message, this->crypto, nonce);
        message->destroy(message);
        return NEED_MORE;
 }
        message->destroy(message);
        return NEED_MORE;
 }
@@ -256,7 +194,7 @@ static status_t process_challenge(private_eap_sim_server_t *this,
        enumerator->destroy(enumerator);
 
        /* verify AT_MAC attribute, signature is over "EAP packet | n*SRES"  */
        enumerator->destroy(enumerator);
 
        /* verify AT_MAC attribute, signature is over "EAP packet | n*SRES"  */
-       if (!in->verify(in, this->signer, this->sreses))
+       if (!in->verify(in, this->crypto, this->sreses))
        {
                DBG1(DBG_IKE, "AT_MAC verification failed");
                return FAILED;
        {
                DBG1(DBG_IKE, "AT_MAC verification failed");
                return FAILED;
@@ -305,7 +243,7 @@ static status_t process(private_eap_sim_server_t *this,
        {
                return FAILED;
        }
        {
                return FAILED;
        }
-       if (!message->parse(message, this->crypter))
+       if (!message->parse(message, this->crypto))
        {
                message->destroy(message);
                return FAILED;
        {
                message->destroy(message);
                return FAILED;
@@ -341,7 +279,7 @@ 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);
        message->add_attribute(message, AT_VERSION_LIST, version);
        message = simaka_message_create(TRUE, this->identifier++,
                                                                        EAP_SIM, SIM_START);
        message->add_attribute(message, AT_VERSION_LIST, version);
-       *out = message->generate(message, NULL, NULL, NULL, chunk_empty);
+       *out = message->generate(message, this->crypto, chunk_empty);
        message->destroy(message);
        return NEED_MORE;
 }
        message->destroy(message);
        return NEED_MORE;
 }
@@ -381,12 +319,8 @@ static bool is_mutual(private_eap_sim_server_t *this)
  */
 static void destroy(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->peer->destroy(this->peer);
-       DESTROY_IF(this->rng);
-       DESTROY_IF(this->hasher);
-       DESTROY_IF(this->prf);
-       DESTROY_IF(this->signer);
-       DESTROY_IF(this->crypter);
        free(this->sreses.ptr);
        free(this->msk.ptr);
        free(this);
        free(this->sreses.ptr);
        free(this->msk.ptr);
        free(this);
@@ -400,14 +334,6 @@ eap_sim_server_t *eap_sim_server_create(identification_t *server,
 {
        private_eap_sim_server_t *this = malloc_thing(private_eap_sim_server_t);
 
 {
        private_eap_sim_server_t *this = malloc_thing(private_eap_sim_server_t);
 
-       this->peer = peer->clone(peer);
-       this->sreses = chunk_empty;
-       this->msk = chunk_empty;
-       /* generate a non-zero identifier */
-       do {
-               this->identifier = random();
-       } while (!this->identifier);
-
        this->public.interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate;
        this->public.interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process;
        this->public.interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
        this->public.interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))initiate;
        this->public.interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))process;
        this->public.interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
@@ -415,18 +341,20 @@ eap_sim_server_t *eap_sim_server_create(identification_t *server,
        this->public.interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
        this->public.interface.destroy = (void(*)(eap_method_t*))destroy;
 
        this->public.interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
        this->public.interface.destroy = (void(*)(eap_method_t*))destroy;
 
-       this->rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
-       this->hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
-       this->prf = lib->crypto->create_prf(lib->crypto, PRF_FIPS_SHA1_160);
-       this->signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_SHA1_128);
-       this->crypter = lib->crypto->create_crypter(lib->crypto, ENCR_AES_CBC, 16);
-       if (!this->rng || !this->hasher || !this->prf ||
-               !this->signer || !this->crypter)
+       this->crypto = simaka_crypto_create();
+       if (!this->crypto)
        {
        {
-               DBG1(DBG_IKE, "unable to use EAP-SIM, missing algorithms");
-               destroy(this);
+               free(this);
                return NULL;
        }
                return NULL;
        }
+       this->peer = peer->clone(peer);
+       this->sreses = chunk_empty;
+       this->msk = chunk_empty;
+       /* generate a non-zero identifier */
+       do {
+               this->identifier = random();
+       } while (!this->identifier);
+
        return &this->public;
 }
 
        return &this->public;
 }