programs/charon/charon/encoding/payloads/nonce_payload.c

   1 /**
   2  * @file nonce_payload.h
   3  *
   4  * @brief Implementation of nonce_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 /* offsetof macro */
  24 #include <stddef.h>
  25
  26 #include "nonce_payload.h"
  27
  28 #include <encoding/payloads/encodings.h>
  29
  30
  31 typedef struct private_nonce_payload_t private_nonce_payload_t;
  32
  33 /**
  34  * Private data of an nonce_payload_t object.
  35  *
  36  */
  37 struct private_nonce_payload_t {
  38         /**
  39          * Public nonce_payload_t interface.
  40          */
  41         nonce_payload_t public;
  42
  43         /**
  44          * Next payload type.
  45          */
  46         u_int8_t  next_payload;
  47
  48         /**
  49          * Critical flag.
  50          */
  51         bool critical;
  52
  53         /**
  54          * Length of this payload.
  55          */
  56         u_int16_t payload_length;
  57
  58         /**
  59          * The contained nonce value.
  60          */
  61         chunk_t nonce;
  62
  63         /**
  64          * @brief Computes the length of this payload.
  65          *
  66          * @param this  calling private_nonce_payload_t object
  67          */
  68         void (*compute_length) (private_nonce_payload_t *this);
  69 };
  70
  71 /**
  72  * Encoding rules to parse or generate a nonce payload
  73  *
  74  * The defined offsets are the positions in a object of type
  75  * private_nonce_payload_t.
  76  *
  77  */
  78 encoding_rule_t nonce_payload_encodings[] = {
  79         /* 1 Byte next payload type, stored in the field next_payload */
  80         { U_INT_8,                      offsetof(private_nonce_payload_t, next_payload)         },
  81         /* the critical bit */
  82         { FLAG,                         offsetof(private_nonce_payload_t, critical)             },
  83         /* 7 Bit reserved bits, nowhere stored */
  84         { RESERVED_BIT, 0                                                                                                               },
  85         { RESERVED_BIT, 0                                                                                                               },
  86         { RESERVED_BIT, 0                                                                                                               },
  87         { RESERVED_BIT, 0                                                                                                               },
  88         { RESERVED_BIT, 0                                                                                                               },
  89         { RESERVED_BIT, 0                                                                                                               },
  90         { RESERVED_BIT, 0                                                                                                               },
  91         /* Length of the whole nonce payload*/
  92         { PAYLOAD_LENGTH,       offsetof(private_nonce_payload_t, payload_length)       },
  93         /* some nonce bytes, lenth is defined in PAYLOAD_LENGTH */
  94         { NONCE_DATA,                   offsetof(private_nonce_payload_t, nonce)                }
  95 };
  96
  97 /*                           1                   2                   3
  98        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
  99       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 100       ! Next Payload  !C!  RESERVED   !         Payload Length        !
 101       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 102       !                                                               !
 103       ~                            Nonce Data                         ~
 104       !                                                               !
 105       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 106 */
 107
 108 /**
 109  * Implementation of payload_t.verify.
 110  */
 111 static status_t verify(private_nonce_payload_t *this)
 112 {
 113         if ((this->nonce.len < 16) || ((this->nonce.len > 256)))
 114         {
 115                 /* nonce length is wrong */
 116                 return FAILED;
 117         }
 118
 119         return SUCCESS;
 120 }
 121
 122 /**
 123  * Implementation of nonce_payload_t.set_nonce.
 124  */
 125 static status_t set_nonce(private_nonce_payload_t *this, chunk_t nonce)
 126 {
 127         this->nonce.ptr = clalloc(nonce.ptr, nonce.len);
 128         this->nonce.len = nonce.len;
 129         this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH + nonce.len;
 130         return SUCCESS;
 131 }
 132
 133 /**
 134  * Implementation of nonce_payload_t.get_nonce.
 135  */
 136 static chunk_t get_nonce(private_nonce_payload_t *this)
 137 {
 138         chunk_t nonce;
 139         nonce.ptr = clalloc(this->nonce.ptr,this->nonce.len);
 140         nonce.len = this->nonce.len;
 141         return nonce;
 142 }
 143
 144 /**
 145  * Implementation of nonce_payload_t.get_encoding_rules.
 146  */
 147 static void get_encoding_rules(private_nonce_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
 148 {
 149         *rules = nonce_payload_encodings;
 150         *rule_count = sizeof(nonce_payload_encodings) / sizeof(encoding_rule_t);
 151 }
 152
 153 /**
 154  * Implementation of payload_t.get_type.
 155  */
 156 static payload_type_t get_type(private_nonce_payload_t *this)
 157 {
 158         return NONCE;
 159 }
 160
 161 /**
 162  * Implementation of payload_t.get_next_type.
 163  */
 164 static payload_type_t get_next_type(private_nonce_payload_t *this)
 165 {
 166         return (this->next_payload);
 167 }
 168
 169 /**
 170  * Implementation of payload_t.set_next_type.
 171  */
 172 static void set_next_type(private_nonce_payload_t *this,payload_type_t type)
 173 {
 174         this->next_payload = type;
 175 }
 176
 177 /**
 178  * Implementation of payload_t.get_length.
 179  */
 180 static size_t get_length(private_nonce_payload_t *this)
 181 {
 182         this->compute_length(this);
 183         return this->payload_length;
 184 }
 185
 186 /**
 187  * Implementation of private_id_payload_t.compute_length.
 188  */
 189 static void compute_length(private_nonce_payload_t *this)
 190 {
 191         this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH + this->nonce.len;
 192 }
 193
 194 /**
 195  * Implementation of payload_t.destroy and nonce_payload_t.destroy.
 196  */
 197 static void destroy(private_nonce_payload_t *this)
 198 {
 199         if (this->nonce.ptr != NULL)
 200         {
 201                 free(this->nonce.ptr);
 202         }
 203
 204         free(this);
 205 }
 206
 207 /*
 208  * Described in header
 209  */
 210 nonce_payload_t *nonce_payload_create()
 211 {
 212         private_nonce_payload_t *this = malloc_thing(private_nonce_payload_t);
 213
 214         /* interface functions */
 215         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 216         this->public.payload_interface.get_encoding_rules = (void (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 217         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 218         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 219         this->public.payload_interface.set_next_type = (void (*) (payload_t *,payload_type_t)) set_next_type;
 220         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
 221         this->public.payload_interface.destroy = (void (*) (payload_t *))destroy;
 222
 223         /* public functions */
 224         this->public.destroy = (void (*) (nonce_payload_t *)) destroy;
 225         this->public.set_nonce = (void (*) (nonce_payload_t *,chunk_t)) set_nonce;
 226         this->public.get_nonce = (chunk_t (*) (nonce_payload_t *)) get_nonce;
 227
 228         /* private functions */
 229         this->compute_length = compute_length;
 230
 231         /* private variables */
 232         this->critical = FALSE;
 233         this->next_payload = NO_PAYLOAD;
 234         this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH;
 235         this->nonce.ptr = NULL;
 236         this->nonce.len = 0;
 237
 238         return (&(this->public));
 239 }
 240
 241