Source/charon/encoding/payloads/ke_payload.c

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