do not store DH redundant in keymat
authorMartin Willi <martin@strongswan.org>
Wed, 29 Oct 2008 13:35:06 +0000 (13:35 -0000)
committerMartin Willi <martin@strongswan.org>
Wed, 29 Oct 2008 13:35:06 +0000 (13:35 -0000)
src/charon/sa/keymat.c
src/charon/sa/keymat.h
src/charon/sa/tasks/ike_init.c

index 4af33dd..cc75a20 100644 (file)
@@ -38,11 +38,6 @@ struct private_keymat_t {
        bool initiator;
        
        /**
-        * diffie hellman key exchange
-        */
-       diffie_hellman_t *dh;
-       
-       /**
         * inbound signer (verify)
         */
        signer_t *signer_in;
@@ -89,29 +84,20 @@ struct private_keymat_t {
 };
 
 /**
- * Implementation of keymat_t.set_dh_group
- */
-static bool set_dh_group(private_keymat_t *this, diffie_hellman_group_t group)
-{
-       DESTROY_IF(this->dh);
-       this->dh = lib->crypto->create_dh(lib->crypto, group);
-       return this->dh != NULL;
-}
-
-/**
- * Implementation of keymat_t.get_dh
+ * Implementation of keymat_t.create_dh
  */
-static diffie_hellman_t* get_dh(private_keymat_t *this)
+static diffie_hellman_t* create_dh(private_keymat_t *this,
+                                                                  diffie_hellman_group_t group)
 {
-       return this->dh;
+       return lib->crypto->create_dh(lib->crypto, group);;
 }
 
 /**
  * Implementation of keymat_t.derive_keys
  */
 static bool derive_keys(private_keymat_t *this, proposal_t *proposal,
-                                               chunk_t nonce_i, chunk_t nonce_r, ike_sa_id_t *id,
-                                               private_keymat_t *rekey)
+                                               diffie_hellman_t *dh, chunk_t nonce_i, chunk_t nonce_r,
+                                               ike_sa_id_t *id, private_keymat_t *rekey)
 {
        chunk_t skeyseed, key, secret, full_nonce, fixed_nonce, prf_plus_seed;
        chunk_t spi_i, spi_r;
@@ -123,7 +109,7 @@ static bool derive_keys(private_keymat_t *this, proposal_t *proposal,
        spi_i = chunk_alloca(sizeof(u_int64_t));
        spi_r = chunk_alloca(sizeof(u_int64_t));
        
-       if (!this->dh || this->dh->get_shared_secret(this->dh, &secret) != SUCCESS)
+       if (dh->get_shared_secret(dh, &secret) != SUCCESS)
        {
                return FALSE;
        }
@@ -420,7 +406,6 @@ static chunk_t get_psk_sig(private_keymat_t *this, bool verify,
  */
 static void destroy(private_keymat_t *this)
 {
-       DESTROY_IF(this->dh);
        DESTROY_IF(this->signer_in);
        DESTROY_IF(this->signer_out);
        DESTROY_IF(this->crypter_in);
@@ -440,9 +425,8 @@ keymat_t *keymat_create(bool initiator)
 {
        private_keymat_t *this = malloc_thing(private_keymat_t);
        
-       this->public.set_dh_group = (bool(*)(keymat_t*, diffie_hellman_group_t group))set_dh_group;
-       this->public.get_dh = (diffie_hellman_t*(*)(keymat_t*))get_dh;
-       this->public.derive_keys = (bool(*)(keymat_t*, proposal_t *proposal, chunk_t nonce_i, chunk_t nonce_r, ike_sa_id_t *id, keymat_t *rekey))derive_keys;
+       this->public.create_dh = (diffie_hellman_t*(*)(keymat_t*, diffie_hellman_group_t group))create_dh;
+       this->public.derive_keys = (bool(*)(keymat_t*, proposal_t *proposal, diffie_hellman_t *dh, chunk_t nonce_i, chunk_t nonce_r, ike_sa_id_t *id, keymat_t *rekey))derive_keys;
        this->public.get_proposal = (proposal_t*(*)(keymat_t*))get_proposal;
        this->public.get_signer = (signer_t*(*)(keymat_t*, bool in))get_signer;
        this->public.get_crypter = (crypter_t*(*)(keymat_t*, bool in))get_crypter;
@@ -453,7 +437,6 @@ keymat_t *keymat_create(bool initiator)
        
        this->initiator = initiator;
        
-       this->dh = NULL;
        this->signer_in = NULL;
        this->signer_out = NULL;
        this->crypter_in = NULL;
index c41c022..d23486d 100644 (file)
@@ -37,23 +37,18 @@ typedef struct keymat_t keymat_t;
  * Derivation an management of sensitive keying material.
  */
 struct keymat_t {
-
-       /**
-        * Set the diffie hellman group to use.
-        *
-        * @param group         diffie hellman group to use
-        * @return                      TRUE if group supported
-        */
-       bool (*set_dh_group)(keymat_t *this, diffie_hellman_group_t group);
        
        /**
-        * Get the diffie hellman key agreement interface.
+        * Create a diffie hellman object for key agreement.
         *
-        * Call set_dh_group() before acquiring this interface.
+        * The diffie hellman is either for IKE negotiation/rekeying or
+        * CHILD_SA rekeying (using PFS). The resulting DH object must be passed
+        * to derive_ike_keys or to derive_child_keys and destroyed after use
         *
-        * @return                      key agreement interface
+        * @param group                 diffie hellman group
+        * @return                              DH object, NULL if group not supported
         */
-       diffie_hellman_t* (*get_dh)(keymat_t *this);
+       diffie_hellman_t* (*create_dh)(keymat_t *this, diffie_hellman_group_t group);
        
        /**
         * Derive keys from the shared secret.
@@ -65,8 +60,9 @@ struct keymat_t {
         * @param rekey         keymat of old SA if we are rekeying
         * @return                      TRUE on success
         */
-       bool (*derive_keys)(keymat_t *this, proposal_t *proposal, chunk_t nonce_i,
-                                               chunk_t nonce_r, ike_sa_id_t *id, keymat_t *rekey);
+       bool (*derive_keys)(keymat_t *this, proposal_t *proposal,
+                                               diffie_hellman_t *dh, chunk_t nonce_i, chunk_t nonce_r,
+                                               ike_sa_id_t *id, keymat_t *rekey);
        /**
         * Get a signer to sign/verify IKE messages.
         *
index bc7d2dd..bbeda15 100644 (file)
@@ -197,10 +197,8 @@ static void process_payloads(private_ike_init_t *this, message_t *message)
                                this->dh_group = ke_payload->get_dh_group_number(ke_payload);
                                if (!this->initiator)
                                {
-                                       if (this->keymat->set_dh_group(this->keymat, this->dh_group))
-                                       {
-                                               this->dh = this->keymat->get_dh(this->keymat);
-                                       }
+                                       this->dh = this->keymat->create_dh(this->keymat,
+                                                                                                          this->dh_group);
                                }
                                if (this->dh)
                                {
@@ -254,13 +252,13 @@ static status_t build_i(private_ike_init_t *this, message_t *message)
        if (!this->dh)
        {
                this->dh_group = this->config->get_dh_group(this->config);
-               if (!this->keymat->set_dh_group(this->keymat, this->dh_group))
+               this->dh = this->keymat->create_dh(this->keymat, this->dh_group);
+               if (!this->dh)
                {
                        DBG1(DBG_IKE, "configured DH group %N not supported",
                                diffie_hellman_group_names, this->dh_group);
                        return FAILED;
                }
-               this->dh = this->keymat->get_dh(this->keymat);
        }
        
        /* generate nonce only when we are trying the first time */
@@ -417,8 +415,8 @@ static status_t build_r(private_ike_init_t *this, message_t *message)
                id->set_initiator_spi(id, this->proposal->get_spi(this->proposal));
                old_keymat = this->old_sa->get_keymat(this->old_sa);
        }
-       if (!this->keymat->derive_keys(this->keymat, this->proposal, this->other_nonce,
-                                                                  this->my_nonce, id, old_keymat))
+       if (!this->keymat->derive_keys(this->keymat, this->proposal, this->dh,
+                                                       this->other_nonce, this->my_nonce, id, old_keymat))
        {
                DBG1(DBG_IKE, "key derivation failed");
                message->add_notify(message, TRUE, NO_PROPOSAL_CHOSEN, chunk_empty);
@@ -524,8 +522,8 @@ static status_t process_i(private_ike_init_t *this, message_t *message)
                id->set_responder_spi(id, this->proposal->get_spi(this->proposal));
                old_keymat = this->old_sa->get_keymat(this->old_sa);
        }
-       if (!this->keymat->derive_keys(this->keymat, this->proposal, this->my_nonce,
-                                                                  this->other_nonce, id, old_keymat))
+       if (!this->keymat->derive_keys(this->keymat, this->proposal, this->dh,
+                                                       this->my_nonce, this->other_nonce, id, old_keymat))
        {
                DBG1(DBG_IKE, "key derivation failed");
                return FAILED;
@@ -568,8 +566,8 @@ static void migrate(private_ike_init_t *this, ike_sa_t *ike_sa)
        
        this->ike_sa = ike_sa;
        this->proposal = NULL;
-       this->keymat->set_dh_group(this->keymat, this->dh_group);
-       this->dh = this->keymat->get_dh(this->keymat);
+       DESTROY_IF(this->dh);
+       this->dh = this->keymat->create_dh(this->keymat, this->dh_group);
 }
 
 /**
@@ -577,6 +575,7 @@ static void migrate(private_ike_init_t *this, ike_sa_t *ike_sa)
  */
 static void destroy(private_ike_init_t *this)
 {
+       DESTROY_IF(this->dh);
        DESTROY_IF(this->proposal);
        chunk_free(&this->my_nonce);
        chunk_free(&this->other_nonce);