src/charon-tkm/src/tkm/tkm_diffie_hellman.c

   1 /*
   2  * Copyrigth (C) 2012 Reto Buerki
   3  * Copyright (C) 2012 Adrian-Ken Rueegsegger
   4  * Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 #include <tkm/client.h>
  18 #include <tkm/constants.h>
  19
  20 #include "tkm.h"
  21 #include "tkm_diffie_hellman.h"
  22
  23 #include <utils/debug.h>
  24
  25 typedef struct private_tkm_diffie_hellman_t private_tkm_diffie_hellman_t;
  26
  27 /**
  28  * Private data of a tkm_diffie_hellman_t object.
  29  */
  30 struct private_tkm_diffie_hellman_t {
  31
  32         /**
  33          * Public tkm_diffie_hellman_t interface.
  34          */
  35         tkm_diffie_hellman_t public;
  36
  37         /**
  38          * Diffie Hellman group number.
  39          */
  40         u_int16_t group;
  41
  42         /**
  43          * Diffie Hellman public value.
  44          */
  45         dh_pubvalue_type pubvalue;
  46
  47         /**
  48          * Context id.
  49          */
  50         dh_id_type context_id;
  51
  52 };
  53
  54 METHOD(diffie_hellman_t, get_my_public_value, void,
  55         private_tkm_diffie_hellman_t *this, chunk_t *value)
  56 {
  57         *value = chunk_alloc(this->pubvalue.size);
  58         memcpy(value->ptr, &this->pubvalue.data, value->len);
  59 }
  60
  61 METHOD(diffie_hellman_t, get_shared_secret, status_t,
  62         private_tkm_diffie_hellman_t *this, chunk_t *secret)
  63 {
  64         dh_key_type shared_secret;
  65         if (ike_dh_get_shared_secret(this->context_id, &shared_secret) != TKM_OK)
  66         {
  67                 return FAILED;
  68         }
  69
  70         *secret = chunk_alloc(shared_secret.size);
  71         memcpy(secret->ptr, &shared_secret.data, secret->len);
  72         return SUCCESS;
  73 }
  74
  75
  76 METHOD(diffie_hellman_t, set_other_public_value, void,
  77         private_tkm_diffie_hellman_t *this, chunk_t value)
  78 {
  79         // TODO: unvoid this function
  80
  81         dh_pubvalue_type othervalue;
  82         othervalue.size = value.len;
  83         memcpy(&othervalue.data, value.ptr, value.len);
  84
  85         ike_dh_generate_key(this->context_id, othervalue);
  86 }
  87
  88 METHOD(diffie_hellman_t, get_dh_group, diffie_hellman_group_t,
  89         private_tkm_diffie_hellman_t *this)
  90 {
  91         return this->group;
  92 }
  93
  94 METHOD(diffie_hellman_t, destroy, void,
  95         private_tkm_diffie_hellman_t *this)
  96 {
  97         if (ike_dh_reset(this->context_id) != TKM_OK)
  98         {
  99                 DBG1(DBG_LIB, "failed to reset DH context %d", this->context_id);
 100         }
 101
 102         tkm->idmgr->release_id(tkm->idmgr, TKM_CTX_DH, this->context_id);
 103         free(this);
 104 }
 105
 106 /*
 107  * Described in header.
 108  */
 109 tkm_diffie_hellman_t *tkm_diffie_hellman_create(diffie_hellman_group_t group)
 110 {
 111         private_tkm_diffie_hellman_t *this;
 112
 113         INIT(this,
 114                 .public = {
 115                         .dh = {
 116                                 .get_shared_secret = _get_shared_secret,
 117                                 .set_other_public_value = _set_other_public_value,
 118                                 .get_my_public_value = _get_my_public_value,
 119                                 .get_dh_group = _get_dh_group,
 120                                 .destroy = _destroy,
 121                         },
 122                 },
 123                 .group = group,
 124                 .context_id = tkm->idmgr->acquire_id(tkm->idmgr, TKM_CTX_DH),
 125         );
 126
 127         if (!this->context_id)
 128         {
 129                 free(this);
 130                 return NULL;
 131         }
 132
 133         if (ike_dh_create(this->context_id, group, &this->pubvalue) != TKM_OK)
 134         {
 135                 free(this);
 136                 return NULL;
 137         }
 138
 139         return &this->public;
 140 }