Source/charon/encoding/payloads/ke_payload.c

   1 /**
   2  * @file ke_payload.c
   3  *
   4  * @brief Declaration of the class ke_payload_t.
   5  *
   6  * An object of this type represents an IKEv2 KE-Payload.
   7  *
   8  * See section 3.4 of RFC for details of this payload type.
   9  *
  10  */
  11
  12 /*
  13  * Copyright (C) 2005 Jan Hutter, Martin Willi
  14  * Hochschule fuer Technik Rapperswil
  15  *
  16  * This program is free software; you can redistribute it and/or modify it
  17  * under the terms of the GNU General Public License as published by the
  18  * Free Software Foundation; either version 2 of the License, or (at your
  19  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  20  *
  21  * This program is distributed in the hope that it will be useful, but
  22  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  23  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  24  * for more details.
  25  */
  26
  27 /* offsetof macro */
  28 #include <stddef.h>
  29
  30 #include "ke_payload.h"
  31
  32 #include <encoding/payloads/encodings.h>
  33 #include <utils/allocator.h>
  34
  35
  36 /**
  37  * Private data of an ke_payload_t Object
  38  *
  39  */
  40 typedef struct private_ke_payload_s private_ke_payload_t;
  41
  42 struct private_ke_payload_s {
  43         /**
  44          * public ke_payload_t interface
  45          */
  46         ke_payload_t public;
  47
  48         /**
  49          * next payload type
  50          */
  51         u_int8_t  next_payload;
  52
  53         /**
  54          * Critical flag
  55          */
  56         bool critical;
  57
  58         /**
  59          * Length of this payload
  60          */
  61         u_int16_t payload_length;
  62
  63
  64         /**
  65          * DH Group Number
  66          */
  67         diffie_hellman_group_t dh_group_number;
  68
  69         /**
  70          * Key Exchange Data of this KE payload
  71          */
  72         chunk_t key_exchange_data;
  73
  74         /**
  75          * @brief Computes the length of this payload.
  76          *
  77          * @param this  calling private_ke_payload_t object
  78          * @return
  79          *                              SUCCESS in any case
  80          */
  81         status_t (*compute_length) (private_ke_payload_t *this);
  82 };
  83
  84 /**
  85  * Encoding rules to parse or generate a IKEv2-KE Payload
  86  *
  87  * The defined offsets are the positions in a object of type
  88  * private_ke_payload_t.
  89  *
  90  */
  91 encoding_rule_t ke_payload_encodings[] = {
  92         /* 1 Byte next payload type, stored in the field next_payload */
  93         { U_INT_8,                      offsetof(private_ke_payload_t, next_payload)            },
  94         /* the critical bit */
  95         { FLAG,                         offsetof(private_ke_payload_t, critical)                        },
  96         /* 7 Bit reserved bits, nowhere stored */
  97         { RESERVED_BIT, 0                                                                                                               },
  98         { RESERVED_BIT, 0                                                                                                               },
  99         { RESERVED_BIT, 0                                                                                                               },
 100         { RESERVED_BIT, 0                                                                                                               },
 101         { RESERVED_BIT, 0                                                                                                               },
 102         { RESERVED_BIT, 0                                                                                                               },
 103         { RESERVED_BIT, 0                                                                                                               },
 104         /* Length of the whole payload*/
 105         { PAYLOAD_LENGTH,       offsetof(private_ke_payload_t, payload_length)          },
 106         /* DH Group number as 16 bit field*/
 107         { U_INT_16,                     offsetof(private_ke_payload_t, dh_group_number)                 },
 108         { RESERVED_BYTE,        0                                                                                                               },
 109         { RESERVED_BYTE,        0                                                                                                               },
 110         /* Key Exchange Data is from variable size */
 111         { KEY_EXCHANGE_DATA,    offsetof(private_ke_payload_t, key_exchange_data)       }
 112 };
 113
 114 /*
 115                            1                   2                   3
 116        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 117       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 118       ! Next Payload  !C!  RESERVED   !         Payload Length        !
 119       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 120       !          DH Group #           !           RESERVED            !
 121       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 122       !                                                               !
 123       ~                       Key Exchange Data                       ~
 124       !                                                               !
 125       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 126 */
 127
 128 /**
 129  * Implements payload_t's verify function.
 130  * See #payload_s.verify for description.
 131  */
 132 static status_t verify(private_ke_payload_t *this)
 133 {
 134         if (this->critical)
 135         {
 136                 /* critical bit is set! */
 137                 return FAILED;
 138         }
 139
 140         /* dh group is not verified in here */
 141         return SUCCESS;
 142 }
 143
 144 /**
 145  * Implements payload_t's and ke_payload_t's destroy function.
 146  * See #payload_s.destroy or ke_payload_s.destroy for description.
 147  */
 148 static status_t destroy(private_ke_payload_t *this)
 149 {
 150         if (this->key_exchange_data.ptr != NULL)
 151         {
 152                 allocator_free(this->key_exchange_data.ptr);
 153         }
 154         allocator_free(this);
 155         return SUCCESS;
 156 }
 157
 158 /**
 159  * Implements payload_t's get_encoding_rules function.
 160  * See #payload_s.get_encoding_rules for description.
 161  */
 162 static status_t get_encoding_rules(private_ke_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
 163 {
 164         *rules = ke_payload_encodings;
 165         *rule_count = sizeof(ke_payload_encodings) / sizeof(encoding_rule_t);
 166
 167         return SUCCESS;
 168 }
 169
 170 /**
 171  * Implements payload_t's get_type function.
 172  * See #payload_s.get_type for description.
 173  */
 174 static payload_type_t get_type(private_ke_payload_t *this)
 175 {
 176         return KEY_EXCHANGE;
 177 }
 178
 179 /**
 180  * Implements payload_t's get_next_type function.
 181  * See #payload_s.get_next_type for description.
 182  */
 183 static payload_type_t get_next_type(private_ke_payload_t *this)
 184 {
 185         return (this->next_payload);
 186 }
 187
 188 /**
 189  * Implements payload_t's set_next_type function.
 190  * See #payload_s.set_next_type for description.
 191  */
 192 static status_t set_next_type(private_ke_payload_t *this,payload_type_t type)
 193 {
 194         this->next_payload = type;
 195         return SUCCESS;
 196 }
 197
 198 /**
 199  * Implements payload_t's get_length function.
 200  * See #payload_s.get_length for description.
 201  */
 202 static size_t get_length(private_ke_payload_t *this)
 203 {
 204         this->compute_length(this);
 205         return this->payload_length;
 206 }
 207
 208 /**
 209  * Implements private_ke_payload_t's compute_length function.
 210  * See #private_ke_payload_s.compute_length for description.
 211  */
 212 static status_t compute_length (private_ke_payload_t *this)
 213 {
 214         size_t length = KE_PAYLOAD_HEADER_LENGTH;
 215         if (this->key_exchange_data.ptr != NULL)
 216         {
 217                 length += this->key_exchange_data.len;
 218         }
 219
 220         this->payload_length = length;
 221
 222         return SUCCESS;
 223 }
 224
 225
 226 /**
 227  * Implements ke_payload_t's get_key_exchange_data function.
 228  * See #ke_payload_t.get_key_exchange_data for description.
 229  */
 230 chunk_t get_key_exchange_data(private_ke_payload_t *this)
 231 {
 232         return (this->key_exchange_data);
 233 }
 234
 235 /**
 236  * Implements ke_payload_t's set_key_exchange_data function.
 237  * See #ke_payload_t.set_key_exchange_data for description.
 238  */
 239 status_t set_key_exchange_data(private_ke_payload_t *this, chunk_t key_exchange_data)
 240 {
 241         /* destroy existing data first */
 242         if (this->key_exchange_data.ptr != NULL)
 243         {
 244                 /* free existing value */
 245                 allocator_free(this->key_exchange_data.ptr);
 246                 this->key_exchange_data.ptr = NULL;
 247                 this->key_exchange_data.len = 0;
 248
 249         }
 250
 251         this->key_exchange_data.ptr = allocator_clone_bytes(key_exchange_data.ptr,key_exchange_data.len);
 252         if (this->key_exchange_data.ptr == NULL)
 253         {
 254                 return OUT_OF_RES;
 255         }
 256         this->key_exchange_data.len = key_exchange_data.len;
 257         this->compute_length(this);
 258
 259         return SUCCESS;
 260 }
 261
 262 /**
 263  * Implements ke_payload_t's get_dh_group_number function.
 264  * See #ke_payload_t.get_dh_group_number for description.
 265  */
 266 diffie_hellman_group_t get_dh_group_number(private_ke_payload_t *this)
 267 {
 268         return this->dh_group_number;
 269 }
 270
 271 /**
 272  * Implements ke_payload_t's set_dh_group_number function.
 273  * See #ke_payload_t.set_dh_group_number for description.
 274  */
 275 status_t set_dh_group_number(private_ke_payload_t *this, diffie_hellman_group_t dh_group_number)
 276 {
 277         this->dh_group_number = dh_group_number;
 278         return SUCCESS;
 279 }
 280
 281 /*
 282  * Described in header
 283  */
 284 ke_payload_t *ke_payload_create()
 285 {
 286         private_ke_payload_t *this = allocator_alloc_thing(private_ke_payload_t);
 287         if (this == NULL)
 288         {
 289                 return NULL;
 290         }
 291         /* interface functions */
 292         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 293         this->public.payload_interface.get_encoding_rules = (status_t (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 294         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 295         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 296         this->public.payload_interface.set_next_type = (status_t (*) (payload_t *,payload_type_t)) set_next_type;
 297         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
 298         this->public.payload_interface.destroy = (status_t (*) (payload_t *))destroy;
 299
 300         /* public functions */
 301         this->public.get_key_exchange_data = (chunk_t (*) (ke_payload_t *)) get_key_exchange_data;
 302         this->public.set_key_exchange_data = (status_t (*) (ke_payload_t *,chunk_t)) set_key_exchange_data;
 303         this->public.get_dh_group_number = (diffie_hellman_group_t (*) (ke_payload_t *)) get_dh_group_number;
 304         this->public.set_dh_group_number =(status_t (*) (ke_payload_t *,diffie_hellman_group_t)) set_dh_group_number;
 305         this->public.destroy = (status_t (*) (ke_payload_t *)) destroy;
 306
 307         /* private functions */
 308         this->compute_length = compute_length;
 309
 310         /* set default values of the fields */
 311         this->critical = KE_PAYLOAD_CRITICAL_FLAG;
 312         this->next_payload = NO_PAYLOAD;
 313         this->payload_length = KE_PAYLOAD_HEADER_LENGTH;
 314         this->key_exchange_data.ptr = NULL;
 315         this->key_exchange_data.len = 0;
 316         this->dh_group_number = 0;
 317
 318         return (&(this->public));
 319 }