src/libcharon/encoding/payloads/nonce_payload.c

   1 /*
   2  * Copyright (C) 2005-2010 Martin Willi
   3  * Copyright (C) 2010 revosec AG
   4  * Copyright (C) 2005 Jan Hutter
   5  * Hochschule fuer Technik Rapperswil
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 #include <stddef.h>
  19
  20 #include "nonce_payload.h"
  21
  22 #include <encoding/payloads/encodings.h>
  23
  24 typedef struct private_nonce_payload_t private_nonce_payload_t;
  25
  26 /**
  27  * Private data of an nonce_payload_t object.
  28  */
  29 struct private_nonce_payload_t {
  30
  31         /**
  32          * Public nonce_payload_t interface.
  33          */
  34         nonce_payload_t public;
  35
  36         /**
  37          * Next payload type.
  38          */
  39         u_int8_t  next_payload;
  40
  41         /**
  42          * Critical flag.
  43          */
  44         bool critical;
  45
  46         /**
  47          * Reserved bits
  48          */
  49         bool reserved[7];
  50
  51         /**
  52          * Length of this payload.
  53          */
  54         u_int16_t payload_length;
  55
  56         /**
  57          * The contained nonce value.
  58          */
  59         chunk_t nonce;
  60
  61         /**
  62          * Payload type, NONCE or NONCE_V1
  63          */
  64         payload_type_t type;
  65 };
  66
  67 /**
  68  * Encoding rules to parse or generate a nonce payload
  69  *
  70  * The defined offsets are the positions in a object of type
  71  * private_nonce_payload_t.
  72  */
  73 static encoding_rule_t encodings[] = {
  74         /* 1 Byte next payload type, stored in the field next_payload */
  75         { U_INT_8,                      offsetof(private_nonce_payload_t, next_payload)         },
  76         /* the critical bit */
  77         { FLAG,                         offsetof(private_nonce_payload_t, critical)                     },
  78         /* 7 Bit reserved bits */
  79         { RESERVED_BIT,         offsetof(private_nonce_payload_t, reserved[0])          },
  80         { RESERVED_BIT,         offsetof(private_nonce_payload_t, reserved[1])          },
  81         { RESERVED_BIT,         offsetof(private_nonce_payload_t, reserved[2])          },
  82         { RESERVED_BIT,         offsetof(private_nonce_payload_t, reserved[3])          },
  83         { RESERVED_BIT,         offsetof(private_nonce_payload_t, reserved[4])          },
  84         { RESERVED_BIT,         offsetof(private_nonce_payload_t, reserved[5])          },
  85         { RESERVED_BIT,         offsetof(private_nonce_payload_t, reserved[6])          },
  86         /* Length of the whole nonce payload*/
  87         { PAYLOAD_LENGTH,       offsetof(private_nonce_payload_t, payload_length)       },
  88         /* some nonce bytes, lenth is defined in PAYLOAD_LENGTH */
  89         { NONCE_DATA,           offsetof(private_nonce_payload_t, nonce)                        },
  90 };
  91
  92 /*                           1                   2                   3
  93        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
  94       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  95       ! Next Payload  !C!  RESERVED   !         Payload Length        !
  96       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  97       !                                                               !
  98       ~                            Nonce Data                         ~
  99       !                                                               !
 100       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 101 */
 102
 103 METHOD(payload_t, verify, status_t,
 104         private_nonce_payload_t *this)
 105 {
 106         if (this->nonce.len < 16 || this->nonce.len > 256)
 107         {
 108                 return FAILED;
 109         }
 110         return SUCCESS;
 111 }
 112
 113 METHOD(payload_t, get_encoding_rules, int,
 114         private_nonce_payload_t *this, encoding_rule_t **rules)
 115 {
 116         *rules = encodings;
 117         return countof(encodings);
 118 }
 119
 120 METHOD(payload_t, get_type, payload_type_t,
 121         private_nonce_payload_t *this)
 122 {
 123         return this->type;
 124 }
 125
 126 METHOD(payload_t, get_next_type, payload_type_t,
 127         private_nonce_payload_t *this)
 128 {
 129         return this->next_payload;
 130 }
 131
 132 METHOD(payload_t, set_next_type, void,
 133         private_nonce_payload_t *this, payload_type_t type)
 134 {
 135         this->next_payload = type;
 136 }
 137
 138 METHOD(payload_t, get_length, size_t,
 139         private_nonce_payload_t *this)
 140 {
 141         return this->payload_length;
 142 }
 143
 144 METHOD(nonce_payload_t, set_nonce, void,
 145          private_nonce_payload_t *this, chunk_t nonce)
 146 {
 147         this->nonce = chunk_clone(nonce);
 148         this->payload_length = NONCE_PAYLOAD_HEADER_LENGTH + nonce.len;
 149 }
 150
 151 METHOD(nonce_payload_t, get_nonce, chunk_t,
 152         private_nonce_payload_t *this)
 153 {
 154         return chunk_clone(this->nonce);
 155 }
 156
 157 METHOD2(payload_t, nonce_payload_t, destroy, void,
 158         private_nonce_payload_t *this)
 159 {
 160         free(this->nonce.ptr);
 161         free(this);
 162 }
 163
 164 /*
 165  * Described in header
 166  */
 167 nonce_payload_t *nonce_payload_create(payload_type_t type)
 168 {
 169         private_nonce_payload_t *this;
 170
 171         INIT(this,
 172                 .public = {
 173                         .payload_interface = {
 174                                 .verify = _verify,
 175                                 .get_encoding_rules = _get_encoding_rules,
 176                                 .get_length = _get_length,
 177                                 .get_next_type = _get_next_type,
 178                                 .set_next_type = _set_next_type,
 179                                 .get_type = _get_type,
 180                                 .destroy = _destroy,
 181                         },
 182                         .set_nonce = _set_nonce,
 183                         .get_nonce = _get_nonce,
 184                         .destroy = _destroy,
 185                 },
 186                 .next_payload = NO_PAYLOAD,
 187                 .payload_length = NONCE_PAYLOAD_HEADER_LENGTH,
 188                 .type = type,
 189         );
 190         return &this->public;
 191 }