forked from osmocom/wireshark
![Pascal Quantin](/assets/img/avatar_default.png)
Bug: 11581 Change-Id: If960e45d5ed71abb3cadcb6dd83832b9098e11a7 Reviewed-on: https://code.wireshark.org/review/10904 Petri-Dish: Anders Broman <a.broman58@gmail.com> Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org> Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>
303 lines
7.2 KiB
C
303 lines
7.2 KiB
C
/* asn1.c
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* Common routines for ASN.1
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* 2007 Anders Broman
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <glib.h>
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#include <string.h>
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#include <stdlib.h>
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#include <math.h>
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#ifdef DEBUG
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#include <stdio.h>
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#endif
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#include <epan/packet.h>
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#include "asn1.h"
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void asn1_ctx_init(asn1_ctx_t *actx, asn1_enc_e encoding, gboolean aligned, packet_info *pinfo) {
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memset(actx, '\0', sizeof(*actx));
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actx->signature = ASN1_CTX_SIGNATURE;
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actx->encoding = encoding;
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actx->aligned = aligned;
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actx->pinfo = pinfo;
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}
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gboolean asn1_ctx_check_signature(asn1_ctx_t *actx) {
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return actx && (actx->signature == ASN1_CTX_SIGNATURE);
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}
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void asn1_ctx_clean_external(asn1_ctx_t *actx) {
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memset(&actx->external, '\0', sizeof(actx->external));
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actx->external.hf_index = -1;
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actx->external.encoding = -1;
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}
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void asn1_ctx_clean_epdv(asn1_ctx_t *actx) {
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memset(&actx->embedded_pdv, '\0', sizeof(actx->embedded_pdv));
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actx->embedded_pdv.hf_index = -1;
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actx->embedded_pdv.identification = -1;
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}
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/*--- stack/parameters ---*/
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void asn1_stack_frame_push(asn1_ctx_t *actx, const gchar *name) {
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asn1_stack_frame_t *frame;
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frame = wmem_new0(wmem_packet_scope(), asn1_stack_frame_t);
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frame->name = name;
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frame->next = actx->stack;
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actx->stack = frame;
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}
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void asn1_stack_frame_pop(asn1_ctx_t *actx, const gchar *name) {
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DISSECTOR_ASSERT(actx->stack);
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DISSECTOR_ASSERT(!strcmp(actx->stack->name, name));
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actx->stack = actx->stack->next;
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}
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void asn1_stack_frame_check(asn1_ctx_t *actx, const gchar *name, const asn1_par_def_t *par_def) {
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const asn1_par_def_t *pd = par_def;
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asn1_par_t *par;
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DISSECTOR_ASSERT(actx->stack);
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DISSECTOR_ASSERT(!strcmp(actx->stack->name, name));
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par = actx->stack->par;
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while (pd->name) {
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DISSECTOR_ASSERT(par);
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DISSECTOR_ASSERT((pd->ptype == ASN1_PAR_IRR) || (par->ptype == pd->ptype));
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par->name = pd->name;
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pd++;
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par = par->next;
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}
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DISSECTOR_ASSERT(!par);
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}
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static asn1_par_t *get_par_by_name(asn1_ctx_t *actx, const gchar *name) {
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asn1_par_t *par = NULL;
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DISSECTOR_ASSERT(actx->stack);
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par = actx->stack->par;
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while (par) {
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if (!strcmp(par->name, name))
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return par;
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par = par->next;
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}
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return par;
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}
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static asn1_par_t *push_new_par(asn1_ctx_t *actx) {
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asn1_par_t *par, **pp;
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DISSECTOR_ASSERT(actx->stack);
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par = wmem_new0(wmem_packet_scope(), asn1_par_t);
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pp = &(actx->stack->par);
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while (*pp)
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pp = &((*pp)->next);
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*pp = par;
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return par;
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}
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void asn1_param_push_boolean(asn1_ctx_t *actx, gboolean value) {
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asn1_par_t *par;
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par = push_new_par(actx);
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par->ptype = ASN1_PAR_BOOLEAN;
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par->value.v_boolean = value;
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}
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void asn1_param_push_integer(asn1_ctx_t *actx, gint32 value) {
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asn1_par_t *par;
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par = push_new_par(actx);
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par->ptype = ASN1_PAR_INTEGER;
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par->value.v_integer = value;
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}
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gboolean asn1_param_get_boolean(asn1_ctx_t *actx, const gchar *name) {
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asn1_par_t *par = NULL;
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par = get_par_by_name(actx, name);
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DISSECTOR_ASSERT(par);
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return par->value.v_boolean;
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}
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gint32 asn1_param_get_integer(asn1_ctx_t *actx, const gchar *name) {
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asn1_par_t *par = NULL;
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par = get_par_by_name(actx, name);
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DISSECTOR_ASSERT(par);
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return par->value.v_integer;
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}
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/*--- ROSE ---*/
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void rose_ctx_init(rose_ctx_t *rctx) {
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memset(rctx, '\0', sizeof(*rctx));
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rctx->signature = ROSE_CTX_SIGNATURE;
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}
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gboolean rose_ctx_check_signature(rose_ctx_t *rctx) {
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return rctx && (rctx->signature == ROSE_CTX_SIGNATURE);
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}
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void rose_ctx_clean_data(rose_ctx_t *rctx) {
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memset(&rctx->d, '\0', sizeof(rctx->d));
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rctx->d.code = -1;
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}
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asn1_ctx_t *get_asn1_ctx(void *ptr) {
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asn1_ctx_t *actx = (asn1_ctx_t*)ptr;
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if (!asn1_ctx_check_signature(actx))
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actx = NULL;
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return actx;
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}
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rose_ctx_t *get_rose_ctx(void *ptr) {
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rose_ctx_t *rctx = (rose_ctx_t*)ptr;
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asn1_ctx_t *actx = (asn1_ctx_t*)ptr;
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if (!asn1_ctx_check_signature(actx))
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actx = NULL;
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if (actx)
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rctx = actx->rose_ctx;
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if (!rose_ctx_check_signature(rctx))
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rctx = NULL;
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return rctx;
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}
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/** Only tested for BER */
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double asn1_get_real(const guint8 *real_ptr, gint len) {
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guint8 octet;
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const guint8 *p;
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guint8 *buf;
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double val = 0;
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/* 8.5.2 If the real value is the value zero,
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* there shall be no contents octets in the encoding.
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*/
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if (len < 1) return val;
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octet = real_ptr[0];
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p = real_ptr + 1;
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len -= 1;
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if (octet & 0x80) { /* binary encoding */
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int i;
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gboolean Eneg;
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gint8 S; /* Sign */
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guint8 B; /* Base */
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guint8 F; /* scaling Factor */
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gint32 E = 0; /* Exponent (supported max 3 octets/24 bit) */
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guint64 N = 0; /* N (supported max 8 octets/64 bit) */
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guint8 lenE, lenN;
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if(octet & 0x40) S = -1; else S = 1;
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switch(octet & 0x30) {
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case 0x00: B = 2; break;
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case 0x10: B = 8; break;
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case 0x20: B = 16; break;
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case 0x30: /* Reserved */
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default:
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/* TODO Add some warning in tree about reserved value for Base */
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return 0;
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}
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F = (octet & 0x0c) >> 2;
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/* 8.5.6.4 Exponent length */
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lenE = (octet & 0x3) + 1;
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if(lenE == 4)
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{
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/* we can't handle exponents > 24 bits */
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/* TODO Next octet(s) define length of exponent */
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DISSECTOR_ASSERT_NOT_REACHED();
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}
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Eneg = (*p) & 0x80 ? TRUE : FALSE;
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for (i = 0; i < lenE; i++) {
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if(Eneg) {
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/* 2's complement: inverse bits */
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E = (E<<8) | ((guint8) ~(*p));
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} else {
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E = (E<<8) | *p;
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}
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p++;
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}
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if(Eneg) {
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/* 2's complement: ... and add 1 (and make negative of course) */
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E = -(E + 1);
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}
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lenN = len - lenE;
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if(lenN > 8)
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{
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/* we can't handle integers > 64 bits */
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DISSECTOR_ASSERT_NOT_REACHED();
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}
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for (i=0; i<lenN; i++) {
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N = (N<<8) | *p;
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p++;
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}
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val = (double) S * N * pow(2, F) * pow(B, E);
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#ifdef DEBUG
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printf("S = %d, N = %lu, F = %u, B = %u, E = %d -> %f\n", S, N, F, B, E, val);
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#endif
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} else if (octet & 0x40) { /* SpecialRealValue */
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switch (octet & 0x3F) {
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case 0x00: val = HUGE_VAL; break;
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case 0x01: val = -HUGE_VAL; break;
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}
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} else { /* decimal encoding */
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buf = g_strndup(p, len);
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val = g_ascii_strtod(buf, NULL);
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g_free(buf);
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}
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return val;
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}
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/*
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* Editor modelines - http://www.wireshark.org/tools/modelines.html
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*
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* Local Variables:
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* c-basic-offset: 2
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* ex: set shiftwidth=2 tabstop=8 expandtab:
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* :indentSize=2:tabSize=8:noTabs=true:
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*/
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