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