Source/charon/payloads/nonce_payload.c

   1 /**
   2  * @file nonce_payload.h
   3  *
   4  * @brief Declaration of the class nonce_payload_t.
   5  *
   6  * An object of this type represents an IKEv2 Nonce-Payload.
   7  *
   8  */
   9
  10 /*
  11  * Copyright (C) 2005 Jan Hutter, Martin Willi
  12  * Hochschule fuer Technik Rapperswil
  13  *
  14  * This program is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU General Public License as published by the
  16  * Free Software Foundation; either version 2 of the License, or (at your
  17  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  18  *
  19  * This program is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  21  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  22  * for more details.
  23  */
  24
  25 /* offsetof macro */
  26 #include <stddef.h>
  27
  28 #include "nonce_payload.h"
  29
  30 #include "encodings.h"
  31 #include "../utils/allocator.h"
  32
  33
  34
  35 /**
  36  * Private data of an nonce_payload_t' Object
  37  *
  38  */
  39 typedef struct private_nonce_payload_s private_nonce_payload_t;
  40
  41 struct private_nonce_payload_s {
  42         /**
  43          * public nonce_payload_t interface
  44          */
  45         nonce_payload_t public;
  46
  47         /**
  48          * next payload type
  49          */
  50         u_int8_t  next_payload;
  51
  52         /**
  53          * Critical flag
  54          */
  55         bool critical;
  56
  57         /**
  58          * Length of this payload
  59          */
  60         u_int16_t payload_length;
  61
  62         /**
  63          * the contained nonce value
  64          */
  65         chunk_t nonce;
  66
  67         /**
  68          * @brief Computes the length of this payload.
  69          *
  70          * @param this  calling private_nonce_payload_t object
  71          * @return
  72          *                              SUCCESS in any case
  73          */
  74         status_t (*compute_length) (private_nonce_payload_t *this);
  75 };
  76
  77 /**
  78  * Encoding rules to parse or generate a nonce payload
  79  *
  80  * The defined offsets are the positions in a object of type
  81  * private_nonce_payload_t.
  82  *
  83  */
  84 encoding_rule_t nonce_payload_encodings[] = {
  85         /* 1 Byte next payload type, stored in the field next_payload */
  86         { U_INT_8,                      offsetof(private_nonce_payload_t, next_payload)         },
  87         /* the critical bit */
  88         { FLAG,                         offsetof(private_nonce_payload_t, critical)             },
  89         /* 7 Bit reserved bits, nowhere stored */
  90         { RESERVED_BIT, 0                                                                                                               },
  91         { RESERVED_BIT, 0                                                                                                               },
  92         { RESERVED_BIT, 0                                                                                                               },
  93         { RESERVED_BIT, 0                                                                                                               },
  94         { RESERVED_BIT, 0                                                                                                               },
  95         { RESERVED_BIT, 0                                                                                                               },
  96         { RESERVED_BIT, 0                                                                                                               },
  97         /* Length of the whole nonce payload*/
  98         { PAYLOAD_LENGTH,       offsetof(private_nonce_payload_t, payload_length)       },
  99         /* some nonce bytes, lenth is defined in PAYLOAD_LENGTH */
 100         { NONCE_DATA,                   offsetof(private_nonce_payload_t, nonce)                }
 101 };
 102
 103 /*                           1                   2                   3
 104        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
 105       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 106       ! Next Payload  !C!  RESERVED   !         Payload Length        !
 107       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 108       !                                                               !
 109       ~                            Nonce Data                         ~
 110       !                                                               !
 111       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 112 */
 113
 114 /**
 115  * Implements payload_t's verify function.
 116  * See #payload_s.verify for description.
 117  */
 118 static status_t verify(private_nonce_payload_t *this)
 119 {
 120         if (this->critical)
 121         {
 122                 /* critical bit is set! */
 123                 return FAILED;
 124         }
 125         if ((this->nonce.len < 16) || ((this->nonce.len > 256)))
 126         {
 127                 /* nonce length is wrong */
 128                 return FAILED;
 129         }
 130
 131         return SUCCESS;
 132 }
 133
 134 /**
 135  * Implements payload_t's and nonce_payload_t's destroy function.
 136  * See #payload_s.destroy or nonce_payload_s.destroy for description.
 137  */
 138 static status_t destroy(private_nonce_payload_t *this)
 139 {
 140         if (this->nonce.ptr != NULL)
 141         {
 142                 allocator_free(this->nonce.ptr);
 143         }
 144         allocator_free(this);
 145
 146         return SUCCESS;
 147 }
 148
 149 /**
 150  * Implements nonce_payload_t's set_nonce function.
 151  * See #nonce_payload_t.set_nonce for description.
 152  */
 153 static status_t set_nonce(private_nonce_payload_t *this, chunk_t nonce)
 154 {
 155         if (nonce.len >= 16 && nonce.len <= 256)
 156         {
 157                 this->nonce.len = nonce.len;
 158                 this->nonce.ptr = nonce.ptr;
 159                 this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH + nonce.len;
 160                 return SUCCESS;
 161         }
 162         return INVALID_ARG;
 163 }
 164
 165 /**
 166  * Implements nonce_payload_t's get_nonce function.
 167  * See #nonce_payload_t.get_nonce for description.
 168  */
 169 static status_t get_nonce(private_nonce_payload_t *this, chunk_t *nonce)
 170 {
 171         nonce->len = this->nonce.len;
 172         nonce->ptr = this->nonce.ptr;
 173         return SUCCESS;
 174 }
 175
 176 /**
 177  * Implements payload_t's get_encoding_rules function.
 178  * See #payload_s.get_encoding_rules for description.
 179  */
 180 static status_t get_encoding_rules(private_nonce_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
 181 {
 182         *rules = nonce_payload_encodings;
 183         *rule_count = sizeof(nonce_payload_encodings) / sizeof(encoding_rule_t);
 184
 185         return SUCCESS;
 186 }
 187
 188 /**
 189  * Implements payload_t's get_type function.
 190  * See #payload_s.get_type for description.
 191  */
 192 static payload_type_t get_type(private_nonce_payload_t *this)
 193 {
 194         return NONCE;
 195 }
 196
 197 /**
 198  * Implements payload_t's get_next_type function.
 199  * See #payload_s.get_next_type for description.
 200  */
 201 static payload_type_t get_next_type(private_nonce_payload_t *this)
 202 {
 203         return (this->next_payload);
 204 }
 205
 206 /**
 207  * Implements payload_t's set_next_type function.
 208  * See #payload_s.set_next_type for description.
 209  */
 210 static status_t set_next_type(private_nonce_payload_t *this,payload_type_t type)
 211 {
 212         this->next_payload = type;
 213         return SUCCESS;
 214 }
 215
 216 /**
 217  * Implements payload_t's get_length function.
 218  * See #payload_s.get_length for description.
 219  */
 220 static size_t get_length(private_nonce_payload_t *this)
 221 {
 222         this->compute_length(this);
 223         return this->payload_length;
 224 }
 225
 226 /*
 227  * Described in header
 228  */
 229 nonce_payload_t *nonce_payload_create()
 230 {
 231         private_nonce_payload_t *this = allocator_alloc_thing(private_nonce_payload_t);
 232         if (this == NULL)
 233         {
 234                 return NULL;
 235         }
 236
 237         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 238         this->public.payload_interface.get_encoding_rules = (status_t (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 239         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 240         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 241         this->public.payload_interface.set_next_type = (status_t (*) (payload_t *,payload_type_t)) set_next_type;
 242         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
 243         this->public.payload_interface.destroy = (status_t (*) (payload_t *))destroy;
 244         this->public.destroy = (status_t (*) (nonce_payload_t *)) destroy;
 245         this->public.set_nonce = (status_t (*) (nonce_payload_t *,chunk_t)) set_nonce;
 246         this->public.get_nonce = (status_t (*) (nonce_payload_t *,chunk_t*)) get_nonce;
 247
 248         this->critical = FALSE;
 249         this->next_payload = NO_PAYLOAD;
 250         this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH;
 251         this->nonce.ptr = NULL;
 252         this->nonce.len = 0;
 253
 254         return (&(this->public));
 255 }
 256
 257