asn1.c

eCos/RedBoot for勤研ARM AnywhereII(4510) 含全部源代码

//==========================================================================
//
//      ./lib/current/src/asn1.c
//
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
//
// eCos 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 or (at your option) any later version.
//
// eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//####UCDSNMPCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from the UCD-SNMP
// project,  <http://ucd-snmp.ucdavis.edu/>  from the University of
// California at Davis, which was originally based on the Carnegie Mellon
// University SNMP implementation.  Portions of this software are therefore
// covered by the appropriate copyright disclaimers included herein.
//
// The release used was version 4.1.2 of May 2000.  "ucd-snmp-4.1.2"
// -------------------------------------------
//
//####UCDSNMPCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    hmt
// Contributors: hmt
// Date:         2000-05-30
// Purpose:      Port of UCD-SNMP distribution to eCos.
// Description:  
//              
//
//####DESCRIPTIONEND####
//
//==========================================================================
/********************************************************************
       Copyright 1989, 1991, 1992 by Carnegie Mellon University

			  Derivative Work -
Copyright 1996, 1998, 1999, 2000 The Regents of the University of California

			 All Rights Reserved

Permission to use, copy, modify and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appears in all copies and
that both that copyright notice and this permission notice appear in
supporting documentation, and that the name of CMU and The Regents of
the University of California not be used in advertising or publicity
pertaining to distribution of the software without specific written
permission.

CMU AND THE REGENTS OF THE UNIVERSITY OF CALIFORNIA DISCLAIM ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL CMU OR
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA BE LIABLE FOR ANY SPECIAL,
INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
FROM THE LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*********************************************************************/
/*
 * Abstract Syntax Notation One, ASN.1
 * As defined in ISO/IS 8824 and ISO/IS 8825
 * This implements a subset of the above International Standards that
 * is sufficient to implement SNMP.
 *
 * Encodes abstract data types into a machine independent stream of bytes.
 *
 */
/**********************************************************************
	Copyright 1988, 1989, 1991, 1992 by Carnegie Mellon University

                      All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in 
supporting documentation, and that the name of CMU not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.  

CMU DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
CMU BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
******************************************************************/
#include <config.h>

#ifdef KINETICS
#include "gw.h"
#endif

#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif

#include <sys/types.h>
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_WINSOCK_H
#include <winsock.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#ifdef vms
#include <in.h>
#endif

#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif

#include "asn1.h"
#include "int64.h"
#include "snmp_debug.h"
#include "mib.h"

#ifndef NULL
#define NULL	0
#endif

#include "snmp_api.h"
#include "snmp_impl.h" /* to define ERROR_MSG */

static
void _asn_size_err(const char *str, size_t wrongsize, size_t rightsize)
{
    char ebuf[128];

    sprintf(ebuf,"%s size %d: s/b %d",str, wrongsize, rightsize);
    ERROR_MSG(ebuf);
}

static
void _asn_length_err(const char *str, size_t wrongsize, size_t rightsize)
{
    char ebuf[128];

    sprintf(ebuf,"%s length %d too large: exceeds %d",str, wrongsize, rightsize);
    ERROR_MSG(ebuf);
}

/*
 * call after asn_parse_length to verify result.
 */
static
int _asn_parse_length_check(const char *str,
                   u_char *bufp, u_char *data,
                   u_long plen, size_t dlen)
{
    char ebuf[128];
    size_t header_len;

    if (bufp == NULL){
	/* error message is set */
	return 1;
    }
    header_len = bufp - data;
    if (((size_t)plen + header_len) > dlen){
	sprintf(ebuf, "%s: message overflow: %d len + %d delta > %d len",
		str, (int)plen, (int)header_len, (int)dlen);
	ERROR_MSG(ebuf);
	return 1;
    }
    return 0;
}

/*
 * call after asn_build_header to verify result.
 */
static
int _asn_build_header_check(const char *str, u_char *data,
                      size_t datalen, size_t typedlen)
{
    char ebuf[128];
    
    if (data == NULL){
	/* error message is set */
	return 1;
    }
    if (datalen < typedlen){
	sprintf(ebuf, "%s: bad header, length too short: %d < %d", str, datalen, typedlen);
	ERROR_MSG(ebuf);
	return 1;
    }
    return 0;
}

/* checks the incoming packet for validity and returns its size or 0 */
int
asn_check_packet (u_char *pkt, size_t len)
{
  u_long asn_length;
  
  if (len < 2)
    return 0;      /* always too short */

  if (*pkt != (u_char)(ASN_SEQUENCE | ASN_CONSTRUCTOR))
    return -1;     /* wrong type */

  if (*(pkt+1) & 0x80) {
    /* long length */
    if ((int)len < (int)(*(pkt+1) & ~0x80)+2)
      return 0;    /* still to short, incomplete length */
    asn_parse_length(pkt+1, &asn_length);
    return (asn_length + 2 + (*(pkt+1) & ~0x80));
  } else {
    /* short length */
    return (*(pkt+1) + 2);
  }
}

static
int _asn_bitstring_check(const char * str, u_long asn_length, u_char datum)
{
    char ebuf[128];

    if (asn_length < 1){
	sprintf(ebuf,"%s: length %d too small", str, (int)asn_length);
	ERROR_MSG(ebuf);
	return 1;
    }
    if (datum > 7){
	sprintf(ebuf,"%s: datum %d >7: too large", str, (int)(datum));
	ERROR_MSG(ebuf);
	return 1;
    }
    return 0;
}

/*
 * asn_parse_int - pulls a long out of an ASN int type.
 *  On entry, datalength is input as the number of valid bytes following
 *   "data".  On exit, it is returned as the number of valid bytes
 *   following the end of this object.
 *
 *  Returns a pointer to the first byte past the end
 *   of this object (i.e. the start of the next object).
 *  Returns NULL on any error.

  u_char * asn_parse_int(
      u_char     *data         IN - pointer to start of object
      int        *datalength   IN/OUT - number of valid bytes left in buffer
      u_char     *type         OUT - asn type of object
      long       *intp         IN/OUT - pointer to start of output buffer
      int         intsize      IN - size of output buffer
*/

u_char *
asn_parse_int(u_char *data,
	      size_t *datalength,
	      u_char *type,
	      long *intp,
	      size_t intsize)
{
/*
 * ASN.1 integer ::= 0x02 asnlength byte {byte}*
 */
    static const char *errpre = "parse int";
    register u_char *bufp = data;
    u_long	    asn_length;
    register long   value = 0;

    if (intsize != sizeof (long)){
	_asn_size_err(errpre, intsize, sizeof(long));
	return NULL;
    }
    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check(errpre, bufp, data, asn_length, *datalength))
	return NULL;

    if ((size_t)asn_length > intsize){
	_asn_length_err(errpre, (size_t)asn_length, intsize);
	return NULL;
    }

    *datalength -= (int)asn_length + (bufp - data);
    if (*bufp & 0x80)
	value = -1; /* integer is negative */

    DEBUGDUMPSETUP("dump_recv", data, bufp - data + asn_length);

    while(asn_length--)
	value = (value << 8) | *bufp++;

    DEBUGMSG(("dump_recv", "  ASN Integer:\t%ld (0x%.2X)\n", value, value));

    *intp = value;
    return bufp;
}


/*
 * asn_parse_unsigned_int - pulls an unsigned long out of an ASN int type.
 *  On entry, datalength is input as the number of valid bytes following
 *   "data".  On exit, it is returned as the number of valid bytes
 *   following the end of this object.
 *
 *  Returns a pointer to the first byte past the end
 *   of this object (i.e. the start of the next object).
 *  Returns NULL on any error.

  u_char * asn_parse_unsigned_int(
      u_char     *data         IN - pointer to start of object
      int        *datalength   IN/OUT - number of valid bytes left in buffer
      u_char     *type         OUT - asn type of object
      u_long     *intp         IN/OUT - pointer to start of output buffer
      int         intsize      IN - size of output buffer
 */
u_char *
asn_parse_unsigned_int(u_char *data,
		       size_t *datalength,
		       u_char *type,
		       u_long *intp,
		       size_t intsize)
{
/*
 * ASN.1 integer ::= 0x02 asnlength byte {byte}*
 */
    static const char *errpre = "parse uint";
    register u_char *bufp = data;
    u_long	    asn_length;
    register u_long value = 0;

    if (intsize != sizeof (long)){
	_asn_size_err(errpre, intsize, sizeof(long));
	return NULL;
    }
    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check(errpre, bufp, data, asn_length, *datalength))
	return NULL;

    if (((int)asn_length > (intsize + 1)) ||
	(((int)asn_length == intsize + 1) && *bufp != 0x00)){
	_asn_length_err(errpre, (size_t)asn_length, intsize);
	return NULL;
    }
    *datalength -= (int)asn_length + (bufp - data);
    if (*bufp & 0x80)
	value = ~value; /* integer is negative */

    DEBUGDUMPSETUP("dump_recv", data, bufp - data + asn_length);

    while(asn_length--)
	value = (value << 8) | *bufp++;

    DEBUGMSG(("dump_recv", "  ASN UInteger:\t%ld (0x%.2X)\n", value, value));

    *intp = value;
    return bufp;