epan/asn1.c

   1 /* asn1.c
   2  * Common routines for ASN.1
   3  * 2007  Anders Broman
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <glib.h>
  29
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include <math.h>
  33
  34 #include <epan/emem.h>
  35 #include <epan/packet.h>
  36
  37 #include "asn1.h"
  38
  39 void asn1_ctx_init(asn1_ctx_t *actx, asn1_enc_e encoding, gboolean aligned, packet_info *pinfo) {
  40   memset(actx, '\0', sizeof(*actx));
  41   actx->signature = ASN1_CTX_SIGNATURE;
  42   actx->encoding = encoding;
  43   actx->aligned = aligned;
  44   actx->pinfo = pinfo;
  45 }
  46
  47 gboolean asn1_ctx_check_signature(asn1_ctx_t *actx) {
  48   return actx && (actx->signature == ASN1_CTX_SIGNATURE);
  49 }
  50
  51 void asn1_ctx_clean_external(asn1_ctx_t *actx) {
  52   memset(&actx->external, '\0', sizeof(actx->external));
  53   actx->external.hf_index = -1;
  54   actx->external.encoding = -1;
  55 }
  56
  57 void asn1_ctx_clean_epdv(asn1_ctx_t *actx) {
  58   memset(&actx->embedded_pdv, '\0', sizeof(actx->embedded_pdv));
  59   actx->embedded_pdv.hf_index = -1;
  60   actx->embedded_pdv.identification = -1;
  61 }
  62
  63
  64 /*--- stack/parameters ---*/
  65
  66 void asn1_stack_frame_push(asn1_ctx_t *actx, const gchar *name) {
  67   asn1_stack_frame_t *frame;
  68
  69   frame = ep_new0(asn1_stack_frame_t);
  70   frame->name = name;
  71   frame->next = actx->stack;
  72   actx->stack = frame;
  73 }
  74
  75 void asn1_stack_frame_pop(asn1_ctx_t *actx, const gchar *name) {
  76   DISSECTOR_ASSERT(actx->stack);
  77   DISSECTOR_ASSERT(!strcmp(actx->stack->name, name));
  78   actx->stack = actx->stack->next;
  79 }
  80
  81 void asn1_stack_frame_check(asn1_ctx_t *actx, const gchar *name, const asn1_par_def_t *par_def) {
  82   const asn1_par_def_t *pd = par_def;
  83   asn1_par_t *par;
  84
  85   DISSECTOR_ASSERT(actx->stack);
  86   DISSECTOR_ASSERT(!strcmp(actx->stack->name, name));
  87
  88   par = actx->stack->par;
  89   while (pd->name) {
  90     DISSECTOR_ASSERT(par);
  91     DISSECTOR_ASSERT((pd->ptype == ASN1_PAR_IRR) || (par->ptype == pd->ptype));
  92     par->name = pd->name;
  93     pd++;
  94     par = par->next;
  95   }
  96   DISSECTOR_ASSERT(!par);
  97 }
  98
  99 static asn1_par_t *get_par_by_name(asn1_ctx_t *actx, const gchar *name) {
 100   asn1_par_t *par = NULL;
 101
 102   DISSECTOR_ASSERT(actx->stack);
 103   par = actx->stack->par;
 104   while (par) {
 105     if (!strcmp(par->name, name))
 106       return par;
 107     par = par->next;
 108   }
 109   return par;
 110 }
 111
 112 static asn1_par_t *push_new_par(asn1_ctx_t *actx) {
 113   asn1_par_t *par, **pp;
 114
 115   DISSECTOR_ASSERT(actx->stack);
 116
 117   par = ep_new0(asn1_par_t);
 118
 119   pp = &(actx->stack->par);
 120   while (*pp)
 121     pp = &((*pp)->next);
 122   *pp = par;
 123
 124   return par;
 125 }
 126
 127 void asn1_param_push_boolean(asn1_ctx_t *actx, gboolean value) {
 128   asn1_par_t *par;
 129
 130   par = push_new_par(actx);
 131   par->ptype = ASN1_PAR_BOOLEAN;
 132   par->value.v_boolean = value;
 133 }
 134
 135 void asn1_param_push_integer(asn1_ctx_t *actx, gint32 value) {
 136   asn1_par_t *par;
 137
 138   par = push_new_par(actx);
 139   par->ptype = ASN1_PAR_INTEGER;
 140   par->value.v_integer = value;
 141 }
 142
 143 gboolean asn1_param_get_boolean(asn1_ctx_t *actx, const gchar *name) {
 144   asn1_par_t *par = NULL;
 145
 146   par = get_par_by_name(actx, name);
 147   DISSECTOR_ASSERT(par);
 148   return par->value.v_boolean;
 149 }
 150
 151 gint32 asn1_param_get_integer(asn1_ctx_t *actx, const gchar *name) {
 152   asn1_par_t *par = NULL;
 153
 154   par = get_par_by_name(actx, name);
 155   DISSECTOR_ASSERT(par);
 156   return par->value.v_integer;
 157 }
 158
 159
 160 /*--- ROSE ---*/
 161
 162 void rose_ctx_init(rose_ctx_t *rctx) {
 163   memset(rctx, '\0', sizeof(*rctx));
 164   rctx->signature = ROSE_CTX_SIGNATURE;
 165 }
 166
 167 gboolean rose_ctx_check_signature(rose_ctx_t *rctx) {
 168   return rctx && (rctx->signature == ROSE_CTX_SIGNATURE);
 169 }
 170
 171 void rose_ctx_clean_data(rose_ctx_t *rctx) {
 172   memset(&rctx->d, '\0', sizeof(rctx->d));
 173   rctx->d.code = -1;
 174 }
 175
 176 asn1_ctx_t *get_asn1_ctx(void *ptr) {
 177   asn1_ctx_t *actx = (asn1_ctx_t*)ptr;
 178
 179   if (!asn1_ctx_check_signature(actx))
 180     actx = NULL;
 181
 182   return actx;
 183 }
 184
 185 rose_ctx_t *get_rose_ctx(void *ptr) {
 186   rose_ctx_t *rctx = (rose_ctx_t*)ptr;
 187   asn1_ctx_t *actx = (asn1_ctx_t*)ptr;
 188
 189   if (!asn1_ctx_check_signature(actx))
 190     actx = NULL;
 191
 192   if (actx)
 193     rctx = actx->rose_ctx;
 194
 195   if (!rose_ctx_check_signature(rctx))
 196     rctx = NULL;
 197
 198   return rctx;
 199 }
 200
 201 double asn1_get_real(const guint8 *real_ptr, gint real_len) {
 202   guint8 octet;
 203   const guint8 *p;
 204   guint8 *buf;
 205   double val = 0;
 206
 207   if (real_len < 1) return val;
 208   octet = real_ptr[0];
 209   p = real_ptr + 1;
 210   real_len -= 1;
 211   if (octet & 0x80) {  /* binary encoding */
 212   } else if (octet & 0x40) {  /* SpecialRealValue */
 213     switch (octet & 0x3F) {
 214       case 0x00: val = HUGE_VAL; break;
 215       case 0x01: val = -HUGE_VAL; break;
 216     }
 217   } else {  /* decimal encoding */
 218     buf = ep_strndup(p, real_len);
 219     val = atof(buf);
 220   }
 221
 222   return val;
 223 }