www.pudn.com > javasnmpv3.rar > asn1.cpp
/*_############################################################################
_##
_## asn1.cpp
_##
_## SNMP++v3.2.22
_## -----------------------------------------------
_## Copyright (c) 2001-2007 Jochen Katz, Frank Fock
_##
_## This software is based on SNMP++2.6 from Hewlett Packard:
_##
_## Copyright (c) 1996
_## Hewlett-Packard Company
_##
_## ATTENTION: USE OF THIS SOFTWARE IS SUBJECT TO THE FOLLOWING TERMS.
_## Permission to use, copy, modify, distribute and/or sell this software
_## and/or its documentation is hereby granted without fee. User agrees
_## to display the above copyright notice and this license notice in all
_## copies of the software and any documentation of the software. User
_## agrees to assume all liability for the use of the software;
_## Hewlett-Packard and Jochen Katz make no representations about the
_## suitability of this software for any purpose. It is provided
_## "AS-IS" without warranty of any kind, either express or implied. User
_## hereby grants a royalty-free license to any and all derivatives based
_## upon this software code base.
_##
_## Stuttgart, Germany, Wed May 2 23:22:30 CEST 2007
_##
_##########################################################################*/
/*===================================================================
Copyright (c) 1999
Hewlett-Packard Company
ATTENTION: USE OF THIS SOFTWARE IS SUBJECT TO THE FOLLOWING TERMS.
Permission to use, copy, modify, distribute and/or sell this software
and/or its documentation is hereby granted without fee. User agrees
to display the above copyright notice and this license notice in all
copies of the software and any documentation of the software. User
agrees to assume all liability for the use of the software; Hewlett-Packard
makes no representations about the suitability of this software for any
purpose. It is provided "AS-IS" without warranty of any kind,either express
or implied. User hereby grants a royalty-free license to any and all
derivatives based upon this software code base.
A S N 1. C P P
ASN encoder / decoder implementation
DESIGN + AUTHOR: Peter E. Mellquist
LANGUAGE: ANSI C++
=====================================================================*/
char asn1_cpp_version[]="#(@) SNMP++ $Id: asn1.cpp 282 2007-03-22 22:03:45Z katz $";
#ifdef __unix
#include /**/
#include /**/
#endif
#include /**/
#ifdef WIN32
#include
#endif
#include "snmp_pp/config_snmp_pp.h"
#include "snmp_pp/asn1.h"
#include "snmp_pp/v3.h"
#include "snmp_pp/snmperrs.h"
#include "snmp_pp/log.h"
#ifdef SNMP_PP_NAMESPACE
namespace Snmp_pp {
#endif
#ifndef NULL
#define NULL 0
#endif
#define LENMASK 0x0ff
#define ASN_UNI_PRIV (ASN_UNIVERSAL | ASN_PRIMITIVE)
#define ASN_SEQ_CON (ASN_SEQUENCE | ASN_CONSTRUCTOR)
/*
* 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.
*/
unsigned char * asn_parse_int( unsigned char *data,
int *datalength,
unsigned char *type,
long int *intp,
int intsize)
{
/*
* ASN.1 integer ::= 0x02 asnlength byte {byte}*
* timestamp 0x43 asnlength byte {byte}*
*/
unsigned char *bufp = data;
unsigned long asn_length;
long value = 0;
if (intsize != sizeof (long)){
ASNERROR("not long");
return NULL;
}
*type = *bufp++;
if ((*type != 0x02) && (*type != 0x43) &&
(*type != 0x41)) {
ASNERROR("Wrong Type. Not an integer");
return NULL;
}
bufp = asn_parse_length(bufp, &asn_length);
if (bufp == NULL){
ASNERROR("bad length");
return NULL;
}
if ((asn_length + (bufp - data)) > (unsigned long)(*datalength)){
ASNERROR("overflow of message");
return NULL;
}
if ((int)asn_length > intsize){
ASNERROR("I don't support such large integers");
return NULL;
}
*datalength -= (int)asn_length + SAFE_INT_CAST(bufp - data);
if (*bufp & 0x80)
value = -1; /* integer is negative */
while(asn_length--)
value = (value << 8) | *bufp++;
*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.
*/
unsigned char * asn_parse_unsigned_int( unsigned char *data,
int *datalength,
unsigned char *type,
unsigned long *intp,
int intsize)
{
/*
* ASN.1 integer ::= 0x02 asnlength byte {byte}*
* 0x43 asnlength byte {byte}*
*/
unsigned char *bufp = data;
unsigned long asn_length;
unsigned long value = 0;
// check the size of the object being requested
if (intsize != sizeof (long)){
ASNERROR("not long");
return NULL;
}
// get the type
*type = *bufp++;
if ((*type != 0x02) && (*type != 0x43) &&
(*type != 0x41) && (*type != 0x42) &&
(*type != 0x47)) {
ASNERROR("Wrong Type. Not an unsigned integer");
return NULL;
}
// pick up the len
bufp = asn_parse_length(bufp, &asn_length);
if (bufp == NULL){
ASNERROR("bad length");
return NULL;
}
// check the len for message overflow
if ((asn_length + (bufp - data)) > (unsigned long)(*datalength)){
ASNERROR("overflow of message");
return NULL;
}
// check for legal uint size
if (( (int)asn_length > 5) || (((int)asn_length > 4) && (*bufp != 0x00))) {
ASNERROR("I don't support such large integers");
return NULL;
}
// check for leading 0 octet
if (*bufp == 0x00) {
bufp++;
asn_length--;
}
// fix the returned data length value
*datalength -= (int)asn_length + SAFE_INT_CAST(bufp - data);
// calculate the value
for (long i=0;i<(long)asn_length;i++)
value = (value << 8) + (unsigned long) *bufp++;
// assign return value
*intp = value;
// return the bumped pointer
return bufp;
}
/*
* asn_build_int - builds an ASN object containing an integer.
* 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.
*/
unsigned char *asn_build_int(unsigned char *data, int *datalength,
const unsigned char type,
const long *intp,
int intsize)
{
/*
* ASN.1 integer ::= 0x02 asnlength byte {byte}*
*/
long integer;
unsigned long mask;
if (intsize != sizeof (long))
return NULL;
integer = *intp;
/*
* Truncate "unnecessary" bytes off of the most significant end of this
* 2's complement integer. There should be no sequence of 9
* consecutive 1's or 0's at the most significant end of the
* integer.
*/
mask = 0x1FFul << ((8 * (sizeof(long) - 1)) - 1);
/* mask is 0xFF800000 on a big-endian machine */
while((((integer & mask) == 0) || ((integer & mask) == mask))
&& intsize > 1){
intsize--;
integer <<= 8;
}
data = asn_build_header(data, datalength, type, intsize);
if (data == NULL)
return NULL;
if (*datalength < intsize)
return NULL;
*datalength -= intsize;
mask = 0xFFul << (8 * (sizeof(long) - 1));
/* mask is 0xFF000000 on a big-endian machine */
while(intsize--){
*data++ = (unsigned char)((integer & mask) >> (8 * (sizeof(long) - 1)));
integer <<= 8;
}
return data;
}
/*
* asn_build_unsigned_int - builds an ASN object containing an integer.
* 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.
*/
unsigned char * asn_build_unsigned_int( unsigned char *data, // modified data
int *datalength, // returned buffer length
unsigned char type, // SMI type
unsigned long *intp, // Uint to encode
int intsize) // size of uint to encode
{
/*
* ASN.1 integer ::= 0x02 asnlength byte {byte}*
*/
unsigned long u_integer;
long u_integer_len;
long x;
// check uint size
if (intsize != sizeof (long))
return NULL;
// local var point to var passed in
u_integer = *intp;
// figure out the len
if ((( u_integer >> 24) & LENMASK) != 0)
u_integer_len = 4;
else if ((( u_integer >> 16) & LENMASK) !=0)
u_integer_len = 3;
else if ((( u_integer >> 8) & LENMASK) !=0)
u_integer_len = 2;
else
u_integer_len =1;
// check for 5 byte len where first byte will be a null
if ((( u_integer >> (8 * (u_integer_len -1))) & 0x080) !=0) {
u_integer_len++;
}
// build up the header
data = asn_build_header( data, // data buffer to be modified
datalength, // length of data buffer
type, // SMI type to enode
(int)u_integer_len); // length of BER encoded item
// special case, add a null byte for len of 5
if ( u_integer_len ==5) {
*data++ = (unsigned char) 0;
for (x=1;x> (8 * ((u_integer_len-1)-x)& LENMASK));
}
else
{
for (x=0;x> (8 * ((u_integer_len-1)-x)& LENMASK));
}
*datalength -= u_integer_len;
return data;
}
/*
* asn_parse_string - pulls an octet string out of an ASN octet string 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 beginning of the next object.
*
* "string" is filled with the octet string.
*
* 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.
*/
unsigned char * asn_parse_string( unsigned char *data,
int *datalength,
unsigned char *type,
unsigned char *str,
int *strlength)
{
/*
* ASN.1 octet string ::= primstring | cmpdstring
* primstring ::= 0x04 asnlength byte {byte}*
* cmpdstring ::= 0x24 asnlength string {string}*
* ipaddress ::= 0x40 4 byte byte byte byte
*/
unsigned char *bufp = data;
unsigned long asn_length;
*type = *bufp++;
if ((*type != 0x04) && (*type != 0x24) &&
(*type != 0x40) && (*type != 0x44) &&
(*type != 0x45)) {
ASNERROR("asn parse string: Wrong Type. Not a string");
return NULL;
}
bufp = asn_parse_length(bufp, &asn_length);
if (bufp == NULL)
return NULL;
if ((asn_length + (bufp - data)) > (unsigned long)(*datalength)){
ASNERROR("asn parse string: overflow of message");
return NULL;
}
if ((int)asn_length > *strlength){
ASNERROR("asn parse string: String to parse is longer than buffer, aborting parsing.");
return NULL;
}
memcpy(str, bufp, asn_length);
*strlength = (int)asn_length;
*datalength -= (int)asn_length + SAFE_INT_CAST(bufp - data);
return bufp + asn_length;
}
/*
* asn_build_string - Builds an ASN octet string object containing the input string.
* 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 beginning of the next 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.
*/
unsigned char *asn_build_string(unsigned char *data,
int *datalength,
const unsigned char type,
const unsigned char *string,
const int strlength)
{
/*
* ASN.1 octet string ::= primstring | cmpdstring
* primstring ::= 0x04 asnlength byte {byte}*
* cmpdstring ::= 0x24 asnlength string {string}*
* This code will never send a compound string.
*/
data = asn_build_header(data, datalength, type, strlength);
if (data == NULL)
return NULL;
if (*datalength < strlength)
return NULL;
// fixed
memcpy((unsigned char *)data, string, strlength);
*datalength -= strlength;
return data + strlength;
}
/*
* asn_parse_header - interprets the ID and length of the current object.
* On entry, datalength is input as the number of valid bytes following
* "data". On exit, it is returned as the number of valid bytes
* in this object following the id and length.
*
* Returns a pointer to the first byte of the contents of this object.
* Returns NULL on any error.
*/
unsigned char *asn_parse_header( unsigned char *data,
int *datalength,
unsigned char *type)
{
unsigned char *bufp = data;
register int header_len;
unsigned long asn_length;
/* this only works on data types < 30, i.e. no extension octets */
if (IS_EXTENSION_ID(*bufp)){
ASNERROR("can't process ID >= 30");
return NULL;
}
*type = *bufp;
bufp = asn_parse_length(bufp + 1, &asn_length);
if (bufp == NULL)
return NULL;
header_len = SAFE_INT_CAST(bufp - data);
if ((unsigned long)(header_len + asn_length) > (unsigned long)*datalength){
ASNERROR("asn length too long");
return NULL;
}
*datalength = (int)asn_length;
return bufp;
}
/*
* asn_build_header - builds an ASN header for an object with the ID and
* length specified.
* On entry, datalength is input as the number of valid bytes following
* "data". On exit, it is returned as the number of valid bytes
* in this object following the id and length.
*
* This only works on data types < 30, i.e. no extension octets.
* The maximum length is 0xFFFF;
*
* Returns a pointer to the first byte of the contents of this object.
* Returns NULL on any error.
*/
unsigned char * asn_build_header( unsigned char *data,
int *datalength,
unsigned char type,
int length)
{
if (*datalength < 1)
return NULL;
*data++ = type;
(*datalength)--;
return asn_build_length(data, datalength, length);
}
/*
* asn_build_sequence - builds an ASN header for a sequence with the ID and
* length specified.
*
* This only works on data types < 30, i.e. no extension octets.
*
* Returns a pointer to the first byte of the contents of this object.
* Returns NULL on any error.
*/
unsigned char * asn_build_sequence( unsigned char *data,
int *datalength,
unsigned char type,
int length)
{
unsigned char * data_with_length;
if( *datalength < 2 ) /* need at least two octets for a sequence */
{
ASNERROR( "build_sequence" );
return NULL;
}
*data++ = type;
(*datalength)--;
data_with_length = asn_build_length( data, datalength, length );
if( data_with_length == NULL )
{
(*datalength)++; /* correct datalength to emulate old behavior of build_sequence */
return NULL;
}
return data_with_length;
}
/*
* asn_parse_length - interprets the length of the current object.
* On exit, length contains the value of this length field.
*
* Returns a pointer to the first byte after this length
* field (aka: the start of the data field).
* Returns NULL on any error.
*/
unsigned char * asn_parse_length( unsigned char *data,
unsigned long *length)
{
unsigned char lengthbyte = *data;
*length = 0;
if (lengthbyte & ASN_LONG_LEN){
lengthbyte &= ~ASN_LONG_LEN; /* turn MSb off */
if (lengthbyte == 0){
ASNERROR("We don't support indefinite lengths");
return NULL;
}
if (lengthbyte > sizeof(int)){
ASNERROR("we can't support data lengths that long");
return NULL;
}
// fixed
memcpy((char *)length, (char *)data + 1, (int)lengthbyte);
*length = ntohl(*length);
// ntohl even on ALPHA (DEC/COMPAQ) 64bit platforms works on 32bit int,
// whereas long is 64bit - therefore:
#ifdef __osf__
*length >>= (8 * ((sizeof(int)) - lengthbyte));
#else
*length >>= (8 * ((sizeof(long)) - lengthbyte));
#endif
// check for length greater than 2^31
if (*length > 0x80000000ul) {
ASNERROR("SNMP does not support data lengths > 2^31");
return NULL;
}
return data + lengthbyte + 1;
} else { /* short asnlength */
*length = (long)lengthbyte;
return data + 1;
}
}
unsigned char *asn_build_length( unsigned char *data,
int *datalength,
int length)
{
unsigned char *start_data = data;
/* no indefinite lengths sent */
if (length < 0x80){
if (*datalength < 1){
ASNERROR("build_length");
return NULL;
}
*data++ = (unsigned char)length;
}
else if (length <= 0xFF){
if (*datalength < 2){
ASNERROR("build_length");
return NULL;
}
*data++ = (unsigned char)(0x01 | ASN_LONG_LEN);
*data++ = (unsigned char)length;
}
else if (length <= 0xFFFF) { /* 0xFF < length <= 0xFFFF */
if (*datalength < 3){
ASNERROR("build_length");
return NULL;
}
*data++ = (unsigned char)(0x02 | ASN_LONG_LEN);
*data++ = (unsigned char)((length >> 8) & 0xFF);
*data++ = (unsigned char)(length & 0xFF);
}
else if (length <= 0xFFFFFF) { /* 0xFF < length <= 0xFFFF */
if (*datalength < 4){
ASNERROR("build_length");
return NULL;
}
*data++ = (unsigned char)(0x03 | ASN_LONG_LEN);
*data++ = (unsigned char)((length >> 16) & 0xFF);
*data++ = (unsigned char)((length >> 8) & 0xFF);
*data++ = (unsigned char)(length & 0xFF);
}
else {
if (*datalength < 5){
ASNERROR("build_length");
return NULL;
}
*data++ = (unsigned char)(0x04 | ASN_LONG_LEN);
*data++ = (unsigned char)((length >> 24) & 0xFF);
*data++ = (unsigned char)((length >> 16) & 0xFF);
*data++ = (unsigned char)((length >> 8) & 0xFF);
*data++ = (unsigned char)(length & 0xFF);
}
*datalength -= SAFE_INT_CAST(data - start_data);
return data;
}
/*
* asn_parse_objid - pulls an object indentifier out of an ASN object identifier 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 beginning of the next object.
*
* "objid" is filled with the object identifier.
*
* 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.
*/
unsigned char *asn_parse_objid( unsigned char *data,
int *datalength,
unsigned char *type,
oid *objid,
int *objidlength)
{
/*
* ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}*
* subidentifier ::= {leadingbyte}* lastbyte
* leadingbyte ::= 1 7bitvalue
* lastbyte ::= 0 7bitvalue
*/
unsigned char *bufp = data;
oid *oidp = objid + 1;
unsigned long subidentifier;
long length;
unsigned long asn_length;
*type = *bufp++;
if (*type != 0x06) {
ASNERROR("Wrong Type. Not an oid");
return NULL;
}
bufp = asn_parse_length(bufp, &asn_length);
if (bufp == NULL)
return NULL;
if ((asn_length + (bufp - data)) > (unsigned long)(*datalength)){
ASNERROR("overflow of message");
return NULL;
}
*datalength -= (int)asn_length + SAFE_INT_CAST(bufp - data);
/* Handle invalid object identifier encodings of the form 06 00 robustly */
if (asn_length == 0)
objid[0] = objid[1] = 0;
length = asn_length;
(*objidlength)--; /* account for expansion of first byte */
while (length > 0 && (*objidlength)-- > 0){
subidentifier = 0;
do { /* shift and add in low order 7 bits */
subidentifier = (subidentifier << 7) + (*(unsigned char *)bufp & ~ASN_BIT8);
length--;
} while (*(unsigned char *)bufp++ & ASN_BIT8); /* last byte has high bit clear */
if (subidentifier > (unsigned long)MAX_SUBID){
ASNERROR("subidentifier too long");
return NULL;
}
*oidp++ = (oid)subidentifier;
}
/*
* The first two subidentifiers are encoded into the first component
* with the value (X * 40) + Y, where:
* X is the value of the first subidentifier.
* Y is the value of the second subidentifier.
*/
subidentifier = (unsigned long)objid[1];
if (subidentifier == 0x2B){
objid[0] = 1;
objid[1] = 3;
} else {
objid[1] = (unsigned char)(subidentifier % 40);
objid[0] = (unsigned char)((subidentifier - objid[1]) / 40);
}
*objidlength = (int)(oidp - objid);
return bufp;
}
/*
* asn_build_objid - Builds an ASN object identifier object containing the
* input string.
* 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 beginning of the next 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.
*/
unsigned char *asn_build_objid( unsigned char *data,
int *datalength,
unsigned char type,
oid *objid,
int objidlength)
{
/*
* ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}*
* subidentifier ::= {leadingbyte}* lastbyte
* leadingbyte ::= 1 7bitvalue
* lastbyte ::= 0 7bitvalue
*/
// F.Fock correct buffer size must be 5*8bit*MAX_OID_LEN
unsigned char buf[MAX_OID_LEN*5];
unsigned char *bp = buf;
oid *op = objid;
int asnlength;
unsigned long subid, mask, testmask;
int bits, testbits;
if (objidlength < 2){
*bp++ = 0;
objidlength = 0;
} else {
*bp++ = (unsigned char) (op[1] + (op[0] * 40));
objidlength -= 2;
op += 2;
}
while(objidlength-- > 0){
subid = *op++;
if (subid < 127){ /* off by one? */
*bp++ = (unsigned char )subid;
} else {
mask = 0x7F; /* handle subid == 0 case */
bits = 0;
/* testmask *MUST* !!!! be of an unsigned type */
for(testmask = 0x7F, testbits = 0; testmask != 0;
testmask <<= 7, testbits += 7){
if (subid & testmask){ /* if any bits set */
mask = testmask;
bits = testbits;
}
}
/* mask can't be zero here */
for(;mask != 0x7F; mask >>= 7, bits -= 7){
/* fix a mask that got truncated above */
if (mask == 0x1E00000)
mask = 0xFE00000;
*bp++ = (unsigned char)(((subid & mask) >> bits) | ASN_BIT8);
}
*bp++ = (unsigned char)(subid & mask);
}
}
asnlength = SAFE_INT_CAST(bp - buf);
data = asn_build_header(data, datalength, type, asnlength);
if (data == NULL)
return NULL;
if (*datalength < asnlength)
return NULL;
// fixed
memcpy((char *)data, (char *)buf, asnlength);
*datalength -= asnlength;
return data + asnlength;
}
/*
* asn_parse_null - Interprets an ASN null 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 beginning of the next 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.
*/
unsigned char *asn_parse_null(unsigned char *data,
int *datalength,
unsigned char *type)
{
/*
* ASN.1 null ::= 0x05 0x00
*/
unsigned char *bufp = data;
unsigned long asn_length;
*type = *bufp++;
if (*type != 0x05) {
ASNERROR("Wrong Type. Not a null");
return NULL;
}
bufp = asn_parse_length(bufp, &asn_length);
if (bufp == NULL)
return NULL;
if (asn_length != 0){
ASNERROR("Malformed NULL");
return NULL;
}
*datalength -= SAFE_INT_CAST(bufp - data);
return bufp + asn_length;
}
/*
* asn_build_null - Builds an ASN null object.
* 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 beginning of the next 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.
*/
unsigned char *asn_build_null( unsigned char *data,
int *datalength,
unsigned char type)
{
/*
* ASN.1 null ::= 0x05 0x00
*/
return asn_build_header(data, datalength, type, 0);
}
/*
* asn_parse_bitstring - pulls a bitstring out of an ASN bitstring 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 beginning of the next object.
*
* "string" is filled with the bit string.
*
* 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.
*/
unsigned char *asn_parse_bitstring( unsigned char *data,
int *datalength,
unsigned char *type,
unsigned char *string,
int *strlength)
{
/*
* bitstring ::= 0x03 asnlength unused {byte}*
*/
unsigned char *bufp = data;
unsigned long asn_length;
*type = *bufp++;
if (*type != 0x03) {
ASNERROR("Wrong Type. Not a bitstring");
return NULL;
}
bufp = asn_parse_length(bufp, &asn_length);
if (bufp == NULL)
return NULL;
if ((asn_length + (bufp - data)) > (unsigned long)(*datalength)){
ASNERROR("overflow of message");
return NULL;
}
if ((int) asn_length > *strlength){
ASNERROR("I don't support such long bitstrings");
return NULL;
}
if (asn_length < 1){
ASNERROR("Invalid bitstring");
return NULL;
}
if (*bufp > 7){
ASNERROR("Invalid bitstring");
return NULL;
}
// fixed
memcpy((char *)string,(char *)bufp, (int)asn_length);
*strlength = (int)asn_length;
*datalength -= (int)asn_length + SAFE_INT_CAST(bufp - data);
return bufp + asn_length;
}
/*
* asn_build_bitstring - Builds an ASN bit string object containing the
* input string.
* 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 beginning of the next 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.
*/
unsigned char *asn_build_bitstring( unsigned char *data,
int *datalength,
unsigned char type,
unsigned char *string,
int strlength)
{
/*
* ASN.1 bit string ::= 0x03 asnlength unused {byte}*
*/
if (strlength < 1 || *string > 7){
ASNERROR("Building invalid bitstring");
return NULL;
}
data = asn_build_header(data, datalength, type, strlength);
if (data == NULL)
return NULL;
if (*datalength < strlength)
return NULL;
// fixed
memcpy((char *)data,(char *)string, strlength);
*datalength -= strlength;
return data + strlength;
}
/*
* asn_parse_unsigned_int64 - pulls a 64 bit 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.
*/
unsigned char * asn_parse_unsigned_int64( unsigned char *data,
int *datalength,
unsigned char *type,
struct counter64 *cp,
int countersize)
{
/*
* ASN.1 integer ::= 0x02 asnlength byte {byte}*
*/
unsigned char *bufp = data;
unsigned long asn_length;
unsigned long low = 0, high = 0;
int intsize = 4;
if (countersize != sizeof(struct counter64)){
ASNERROR("not right size");
return NULL;
}
*type = *bufp++;
if ((*type != 0x02) && (*type != 0x46)) {
ASNERROR("Wrong Type. Not an integer 64");
return NULL;
}
bufp = asn_parse_length(bufp, &asn_length);
if (bufp == NULL){
ASNERROR("bad length");
return NULL;
}
if ((asn_length + (bufp - data)) > (unsigned long)(*datalength)){
ASNERROR("overflow of message");
return NULL;
}
if (((int)asn_length > (intsize * 2 + 1)) ||
(((int)asn_length == (intsize * 2) + 1) && *bufp != 0x00)){
ASNERROR("I don't support such large integers");
return NULL;
}
*datalength -= (int)asn_length + SAFE_INT_CAST(bufp - data);
if (*bufp & 0x80){
low = (unsigned long) -1; // integer is negative
high = (unsigned long) -1;
}
while(asn_length--){
high = (high << 8) | ((low & 0xFF000000) >> 24);
low = (low << 8) | *bufp++;
}
cp->low = low;
cp->high = high;
return bufp;
}
/*
* asn_build_unsigned_int64 - builds an ASN object containing a 64 bit integer.
* 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.
*/
unsigned char * asn_build_unsigned_int64( unsigned char *data,
int *datalength,
unsigned char type,
struct counter64 *cp,
int countersize)
{
/*
* ASN.1 integer ::= 0x02 asnlength byte {byte}*
*/
unsigned long low, high;
unsigned long mask, mask2;
int add_null_byte = 0;
int intsize;
if (countersize != sizeof (struct counter64))
return NULL;
intsize = 8;
low = cp->low;
high = cp->high;
mask = 0xFFul << (8 * (sizeof(long) - 1));
/* mask is 0xFF000000 on a big-endian machine */
if ((unsigned char)((high & mask) >> (8 * (sizeof(long) - 1))) & 0x80){
/* if MSB is set */
add_null_byte = 1;
intsize++;
}
else {
/*
* Truncate "unnecessary" bytes off of the most significant end of this 2's
* complement integer.
* There should be no sequence of 9 consecutive 1's or 0's at the most
* significant end of the integer.
*/
mask2 = 0x1FFul << ((8 * (sizeof(long) - 1)) - 1);
/* mask2 is 0xFF800000 on a big-endian machine */
while((((high & mask2) == 0) || ((high & mask2) == mask2))
&& intsize > 1){
intsize--;
high = (high << 8)
| ((low & mask) >> (8 * (sizeof(long) - 1)));
low <<= 8;
}
}
data = asn_build_header(data, datalength, type, intsize);
if (data == NULL)
return NULL;
if (*datalength < intsize)
return NULL;
*datalength -= intsize;
if (add_null_byte == 1){
*data++ = '\0';
intsize--;
}
while(intsize--){
*data++ = (unsigned char)((high & mask) >> (8 * (sizeof(long) - 1)));
high = (high << 8)
| ((low & mask) >> (8 * (sizeof(long) - 1)));
low <<= 8;
}
return data;
}
// create a pdu
struct snmp_pdu * snmp_pdu_create( int command)
{
struct snmp_pdu *pdu;
pdu = (struct snmp_pdu *)malloc(sizeof(struct snmp_pdu));
memset((char *)pdu, 0,sizeof(struct snmp_pdu));
pdu->command = command;
#ifdef _SNMPv3
pdu->msgid = 0;
#endif
pdu->errstat = 0;
pdu->errindex = 0;
pdu->enterprise = NULL;
pdu->enterprise_length = 0;
pdu->variables = NULL;
return pdu;
}
// free content and clear pointers
void clear_pdu(struct snmp_pdu *pdu, bool clear_all)
{
struct variable_list *vp, *ovp;
vp = pdu->variables;
while (vp)
{
if (vp->name) free((char *)vp->name); // free the oid part
if (vp->val.string) free((char *)vp->val.string); // free deep data
ovp = vp;
vp = vp->next_variable; // go to the next one
free((char *)ovp); // free up vb itself
}
pdu->variables = NULL;
// if enterprise free it up
if (pdu->enterprise)
free((char *)pdu->enterprise);
pdu->enterprise = NULL;
if (!clear_all) return;
pdu->command = 0;
pdu->reqid = 0;
#ifdef _SNMPv3
pdu->msgid = 0;
pdu->maxsize_scopedpdu = 0;
#endif
pdu->errstat = 0;
pdu->errindex = 0;
pdu->enterprise_length = 0;
pdu->trap_type = 0;
pdu->specific_type = 0;
pdu->time = 0;
}
// free a pdu
void snmp_free_pdu( struct snmp_pdu *pdu)
{
clear_pdu(pdu); // clear and free content
free((char *)pdu); // free up pdu itself
}
// add a null var to a pdu
void snmp_add_var(struct snmp_pdu *pdu,
oid *name,
int name_length,
SmiVALUE *smival)
{
struct variable_list *vars;
// if we don't have a vb list ,create one
if (pdu->variables == NULL)
pdu->variables = vars = (struct variable_list *)malloc(sizeof(struct variable_list));
else
{
// we have one, find the end
vars = pdu->variables;
while (vars->next_variable) vars = vars->next_variable;
// create a new one
vars->next_variable = (struct variable_list *)malloc(sizeof(struct variable_list));
// bump ptr
vars = vars->next_variable;
}
// add the oid with no data
vars->next_variable = NULL;
// hook in the Oid portion
vars->name = (oid *)malloc(name_length * sizeof(oid));
// fixed
memcpy((char *)vars->name,(char *)name, name_length * sizeof(oid));
vars->name_length = name_length;
// hook in the SMI value
switch( smival->syntax)
{
// null , do nothing
case sNMP_SYNTAX_NULL:
case sNMP_SYNTAX_NOSUCHOBJECT:
case sNMP_SYNTAX_NOSUCHINSTANCE:
case sNMP_SYNTAX_ENDOFMIBVIEW:
{
vars->type = (unsigned char) smival->syntax;
vars->val.string = NULL;
vars->val_len = 0;
}
break;
// octects
case sNMP_SYNTAX_OCTETS:
case sNMP_SYNTAX_OPAQUE:
case sNMP_SYNTAX_IPADDR:
{
vars->type = (unsigned char) smival->syntax;
vars->val.string = (unsigned char *)malloc((unsigned)smival->value.string.len);
vars->val_len = (int) smival->value.string.len;
memcpy( (unsigned char *) vars->val.string,
(unsigned char *) smival->value.string.ptr,
(unsigned) smival->value.string.len);
}
break;
// oid
case sNMP_SYNTAX_OID:
{
vars->type = (unsigned char) smival->syntax;
vars->val_len = (int) smival->value.oid.len * sizeof(oid);
vars->val.objid = (oid *)malloc((unsigned)vars->val_len);
memcpy((unsigned long *)vars->val.objid,
(unsigned long *)smival->value.oid.ptr,
(unsigned) vars->val_len);
}
break;
case sNMP_SYNTAX_TIMETICKS:
case sNMP_SYNTAX_CNTR32:
case sNMP_SYNTAX_GAUGE32:
// case sNMP_SYNTAX_UINT32:
{
long templong;
vars->type = (unsigned char) smival->syntax;
vars->val.integer = (long *)malloc(sizeof(long));
vars->val_len = sizeof(long);
templong = (long) smival->value.uNumber;
memcpy( (long*) vars->val.integer,
(long*) &templong,
sizeof(long));
}
break;
case sNMP_SYNTAX_INT32:
{
long templong;
vars->type = (unsigned char) smival->syntax;
vars->val.integer = (long *)malloc(sizeof(long));
vars->val_len = sizeof(long);
templong = (long) smival->value.sNumber;
memcpy( (long*) vars->val.integer,
(long*) &templong,
sizeof(long));
}
break;
// 64 bit counter
case sNMP_SYNTAX_CNTR64:
{
vars->type = ( unsigned char) smival->syntax;
vars->val.counter64 = (struct counter64 *)malloc( sizeof(struct counter64) );
vars->val_len = sizeof(struct counter64);
memcpy( (struct counter64*) vars->val.counter64,
(SmiLPCNTR64) &(smival->value.hNumber),
sizeof( SmiCNTR64));
}
break;
} // end switch
}
// build the authentication, works for v1 or v2c
static unsigned char *snmp_auth_build(unsigned char *data,
int *length,
const long int version,
const unsigned char *community,
const int community_len,
const int messagelen)
{
// 5 is 3 octets for version and 2 for community header + len
// This assumes that community will not be longer than 0x7f chars.
data = asn_build_sequence(data, length,
(unsigned char)(ASN_SEQUENCE | ASN_CONSTRUCTOR),
messagelen + community_len + 5);
if (data == NULL){
ASNERROR("buildheader");
return NULL;
}
data = asn_build_int(data, length,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
&version, sizeof(version));
if (data == NULL){
ASNERROR("buildint");
return NULL;
}
data = asn_build_string(data, length,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OCTET_STR),
community, community_len);
if (data == NULL){
ASNERROR("buildstring");
return NULL;
}
return data;
}
// build a variable binding
unsigned char * snmp_build_var_op(unsigned char *data,
oid * var_name,
int *var_name_len,
unsigned char var_val_type,
int var_val_len,
unsigned char *var_val,
int *listlength)
{
int valueLen;
Buffer buffer(MAX_SNMP_PACKET);
unsigned char *buffer_pos = buffer.get_ptr();
int bufferLen = MAX_SNMP_PACKET;
buffer_pos = asn_build_objid( buffer_pos,
&bufferLen,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OBJECT_ID),
var_name,
*var_name_len);
if (buffer_pos == NULL){
ASNERROR("build_var_op: build_objid failed");
return NULL;
}
// based on the type...
switch(var_val_type){
case ASN_INTEGER:
buffer_pos = asn_build_int(buffer_pos, &bufferLen,
var_val_type,
(long *)var_val, var_val_len);
break;
case SMI_GAUGE:
case SMI_COUNTER:
case SMI_TIMETICKS:
case SMI_UINTEGER:
buffer_pos = asn_build_unsigned_int(buffer_pos, &bufferLen,
var_val_type,
(unsigned long *)var_val, var_val_len);
break;
case SMI_COUNTER64:
buffer_pos = asn_build_unsigned_int64(buffer_pos, &bufferLen,
var_val_type,
(struct counter64 *)var_val,
var_val_len);
break;
case ASN_OCTET_STR:
case SMI_IPADDRESS:
case SMI_OPAQUE:
case SMI_NSAP:
buffer_pos = asn_build_string(buffer_pos, &bufferLen, var_val_type,
var_val, var_val_len);
break;
case ASN_OBJECT_ID:
buffer_pos = asn_build_objid(buffer_pos, &bufferLen, var_val_type,
(oid *)var_val, var_val_len / sizeof(oid));
break;
case ASN_NULL:
buffer_pos = asn_build_null(buffer_pos, &bufferLen, var_val_type);
break;
case ASN_BIT_STR:
buffer_pos = asn_build_bitstring(buffer_pos, &bufferLen, var_val_type,
var_val, var_val_len);
break;
case SNMP_NOSUCHOBJECT:
case SNMP_NOSUCHINSTANCE:
case SNMP_ENDOFMIBVIEW:
buffer_pos = asn_build_null(buffer_pos, &bufferLen, var_val_type);
break;
default:
ASNERROR("build_var_op: wrong type");
return NULL;
}
if (buffer_pos == NULL){
ASNERROR("build_var_op: value build failed");
return NULL;
}
valueLen = SAFE_INT_CAST(buffer_pos - buffer.get_ptr());
data = asn_build_sequence(data, listlength,
(unsigned char)(ASN_SEQUENCE | ASN_CONSTRUCTOR),
valueLen);
if( data == NULL || *listlength < valueLen )
{
ASNERROR( "build_var_op" );
data = NULL;
}
else
{
memcpy(data, buffer.get_ptr(), valueLen );
data += valueLen;
(*listlength)-=valueLen;
}
return data;
}
unsigned char *build_vb(struct snmp_pdu *pdu,
unsigned char *buf, int *buf_len)
{
Buffer tmp_buf(MAX_SNMP_PACKET);
unsigned char *cp = tmp_buf.get_ptr();
struct variable_list *vp;
int vb_length;
int length = MAX_SNMP_PACKET;
// build varbinds into packet buffer
for(vp = pdu->variables; vp; vp = vp->next_variable)
{
cp = snmp_build_var_op( cp, vp->name, &vp->name_length,
vp->type, vp->val_len,
(unsigned char *)vp->val.string,
&length);
if (cp == NULL) return 0;
}
vb_length = SAFE_INT_CAST(cp - tmp_buf.get_ptr());
*buf_len -= vb_length;
if (*buf_len <= 0) return 0;
// encode the length of encoded varbinds into buf
cp = asn_build_header( buf, buf_len,
(unsigned char)(ASN_SEQUENCE | ASN_CONSTRUCTOR),
vb_length);
if (cp == NULL) return 0;
// copy varbinds from packet behind header in buf
memcpy(cp, tmp_buf.get_ptr(), vb_length);
return (cp + vb_length);
}
unsigned char *build_data_pdu(struct snmp_pdu *pdu,
unsigned char *buf, int *buf_len,
unsigned char *vb_buf, int vb_buf_len)
{
Buffer tmp_buf(MAX_SNMP_PACKET);
unsigned char *cp = tmp_buf.get_ptr();
int totallength;
int length = MAX_SNMP_PACKET;
// build data of pdu into tmp_buf
if (pdu->command != TRP_REQ_MSG)
{
// request id
cp = asn_build_int( cp, &length,
(unsigned char )(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
(long *)&pdu->reqid, sizeof(pdu->reqid));
if (cp == NULL) return 0;
// error status
cp = asn_build_int(cp, &length,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
(long *)&pdu->errstat, sizeof(pdu->errstat));
if (cp == NULL) return 0;
// error index
cp = asn_build_int(cp, &length,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
(long *)&pdu->errindex, sizeof(pdu->errindex));
if (cp == NULL) return 0;
}
else
{ // this is a trap message
// enterprise
cp = asn_build_objid( cp, &length,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OBJECT_ID),
(oid *)pdu->enterprise, pdu->enterprise_length);
if (cp == NULL) return 0;
// agent-addr ; must be IPADDRESS changed by Frank Fock
cp = asn_build_string(cp, &length,
(unsigned char)(SMI_IPADDRESS),
(unsigned char *)&pdu->agent_addr.sin_addr.s_addr,
sizeof(pdu->agent_addr.sin_addr.s_addr));
if (cp == NULL) return 0;
long dummy = pdu->trap_type;
// generic trap
cp = asn_build_int(cp, &length,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
&dummy, sizeof(dummy));
if (cp == NULL) return 0;
dummy = pdu->specific_type;
// specific trap
cp = asn_build_int( cp, &length,
(unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_INTEGER),
&dummy, sizeof(dummy));
if (cp == NULL) return 0;
// timestamp
cp = asn_build_unsigned_int(cp, &length,
(unsigned char )(SMI_TIMETICKS),
&pdu->time, sizeof(pdu->time));
if (cp == NULL) return 0;
}
if (length < vb_buf_len) return 0;
// save relative position of varbinds
int vb_rel_pos = SAFE_INT_CAST(cp - tmp_buf.get_ptr());
totallength = SAFE_INT_CAST(cp - tmp_buf.get_ptr()) + vb_buf_len;
// build header for datapdu into buf
cp = asn_build_header(buf, buf_len,
(unsigned char)pdu->command, totallength);
if (cp == NULL) return 0;
if (*buf_len < totallength) return 0;
// copy data behind header
memcpy(cp, tmp_buf.get_ptr(), totallength - vb_buf_len);
memcpy((char *)cp + vb_rel_pos, (char *)vb_buf, vb_buf_len);
*buf_len -= totallength;
return (cp + totallength);
}
// serialize the pdu
int snmp_build(struct snmp_pdu *pdu,
unsigned char *packet, int *out_length,
const long version,
const unsigned char* community, const int community_len)
{
Buffer buf(MAX_SNMP_PACKET);
unsigned char *cp;
int length;
int totallength;
// encode vbs with header into packet
length = *out_length;
cp = build_vb(pdu, packet, &length);
if (cp == 0) return -1;
totallength = SAFE_INT_CAST(cp - packet);
if (totallength >= *out_length) return -1;
// encode datadpu into buf
length = MAX_SNMP_PACKET;
cp = build_data_pdu(pdu, buf.get_ptr(), &length,
packet, totallength);
if (cp == 0) return -1;
totallength = SAFE_INT_CAST(cp - buf.get_ptr());
if (totallength >= *out_length) return -1;
// build SNMP header
length = *out_length;
cp = snmp_auth_build( packet, &length, version,
community, community_len, totallength );
if (cp == NULL) return -1;
if ((*out_length - (cp - packet)) < totallength) return -1;
// copy data
memcpy(cp, buf.get_ptr(), totallength);
totallength += SAFE_INT_CAST(cp - packet);
*out_length = totallength;
return 0;
}
// parse the authentication header
static unsigned char *snmp_auth_parse(unsigned char *data,
int *length,
unsigned char *community,
int *community_len,
long *version)
{
unsigned char type;
// get the type
data = asn_parse_header(data, length, &type);
if (data == NULL){
ASNERROR("bad header");
return NULL;
}
if (type != (ASN_SEQUENCE | ASN_CONSTRUCTOR)){
ASNERROR("wrong auth header type");
return NULL;
}
// get the version
data = asn_parse_int(data, length, &type, version, sizeof(*version));
if (data == NULL){
ASNERROR("bad parse of version");
return NULL;
}
// get the community name
data = asn_parse_string(data, length, &type, community, community_len);
if (data == NULL){
ASNERROR("bad parse of community");
return NULL;
}
return (unsigned char *)data;
}
unsigned char *
snmp_parse_var_op( unsigned char *data, // IN - pointer to the start of object
oid *var_name, // OUT - object id of variable
int *var_name_len, // IN/OUT - length of variable name
unsigned char *var_val_type, // OUT - type of variable (int or octet string) (one byte)
int *var_val_len, // OUT - length of variable
unsigned char **var_val, // OUT - pointer to ASN1 encoded value of variable
int *listlength) // IN/OUT - number of valid bytes left in var_op_list
{
unsigned char var_op_type;
int var_op_len = *listlength;
unsigned char *var_op_start = data;
data = asn_parse_header(data, &var_op_len, &var_op_type);
if (data == NULL){
ASNERROR("Error snmp_parse_var_op: 1");
return NULL;
}
if (var_op_type != (unsigned char)(ASN_SEQUENCE | ASN_CONSTRUCTOR))
return NULL;
data = asn_parse_objid(data, &var_op_len, &var_op_type, var_name, var_name_len);
if (data == NULL){
ASNERROR("Error snmp_parse_var_op: 2");
return NULL;
}
if (var_op_type != (unsigned char)(ASN_UNIVERSAL | ASN_PRIMITIVE | ASN_OBJECT_ID))
return NULL;
*var_val = data; /* save pointer to this object */
/* find out what type of object this is */
data = asn_parse_header(data, &var_op_len, var_val_type);
if (data == NULL){
ASNERROR("Error snmp_parse_var_op: 3");
return NULL;
}
if (((unsigned long)var_op_len + (data - var_op_start)) > (unsigned long)(*listlength)) {
ASNERROR("Error snmp_parse_var_op: 4");
return NULL;
}
*var_val_len = (int)var_op_len;
data += var_op_len;
*listlength -= (int)(data - var_op_start);
return data;
}
int snmp_parse_vb(struct snmp_pdu *pdu, unsigned char *&data, int &data_len)
{
unsigned char *var_val;
int len;
struct variable_list *vp = 0;
oid objid[ASN_MAX_NAME_LEN], *op;
unsigned char type;
// get the vb list from received data
data = asn_parse_header(data, &data_len, &type);
if (data == NULL)
return SNMP_CLASS_ASN1ERROR;
if (type != (unsigned char)(ASN_SEQUENCE | ASN_CONSTRUCTOR))
return SNMP_CLASS_ASN1ERROR;
pdu->variables = NULL;
while(data_len > 0){
if (pdu->variables == NULL){
pdu->variables = vp = (struct variable_list *)malloc(sizeof(struct variable_list));
} else {
vp->next_variable = (struct variable_list *)malloc(sizeof(struct variable_list));
vp = vp->next_variable;
}
vp->next_variable = NULL;
vp->val.string = NULL;
vp->name = NULL;
vp->name_length = ASN_MAX_NAME_LEN;
data = snmp_parse_var_op( data, objid, &vp->name_length, &vp->type,
&vp->val_len, &var_val, &data_len);
if (data == NULL)
return SNMP_CLASS_ASN1ERROR;
op = (oid *)malloc((unsigned)vp->name_length * sizeof(oid));
// fixed
memcpy((char *)op, (char *)objid, vp->name_length * sizeof(oid));
vp->name = op;
len = MAX_SNMP_PACKET;
switch((short)vp->type){
case ASN_INTEGER:
vp->val.integer = (long *)malloc(sizeof(long));
vp->val_len = sizeof(long);
asn_parse_int(var_val, &len, &vp->type, (long *)vp->val.integer, sizeof(*vp->val.integer));
break;
case SMI_COUNTER:
case SMI_GAUGE:
case SMI_TIMETICKS:
case SMI_UINTEGER:
vp->val.integer = (long *)malloc(sizeof(long));
vp->val_len = sizeof(long);
asn_parse_unsigned_int(var_val, &len, &vp->type, (unsigned long *)vp->val.integer, sizeof(*vp->val.integer));
break;
case SMI_COUNTER64:
vp->val.counter64 = (struct counter64 *)malloc( sizeof(struct counter64) );
vp->val_len = sizeof(struct counter64);
asn_parse_unsigned_int64(var_val, &len, &vp->type,
(struct counter64 *)vp->val.counter64,
sizeof(*vp->val.counter64));
break;
case ASN_OCTET_STR:
case SMI_IPADDRESS:
case SMI_OPAQUE:
case SMI_NSAP:
vp->val.string = (unsigned char *)malloc((unsigned)vp->val_len);
asn_parse_string(var_val, &len, &vp->type, vp->val.string, &vp->val_len);
break;
case ASN_OBJECT_ID:
vp->val_len = ASN_MAX_NAME_LEN;
asn_parse_objid(var_val, &len, &vp->type, objid, &vp->val_len);
//vp->val_len *= sizeof(oid);
vp->val.objid = (oid *)malloc((unsigned)vp->val_len * sizeof(oid));
// fixed
memcpy((char *)vp->val.objid,
(char *)objid,
vp->val_len * sizeof(oid));
break;
case SNMP_NOSUCHOBJECT:
case SNMP_NOSUCHINSTANCE:
case SNMP_ENDOFMIBVIEW:
case ASN_NULL:
break;
default:
ASNERROR("bad type returned ");
return SNMP_CLASS_ASN1ERROR;
break;
}
}
return SNMP_CLASS_SUCCESS;
}
int snmp_parse_data_pdu(snmp_pdu *pdu, unsigned char *&data, int &length)
{
oid objid[ASN_MAX_NAME_LEN];
int four = 4;
unsigned char type;
data = asn_parse_header(data, &length, &type);
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
pdu->command = type;
if (pdu->command != TRP_REQ_MSG)
{
// get the rid
data = asn_parse_int(data, &length, &type,
(long *)&pdu->reqid, sizeof(pdu->reqid));
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
// get the error status
data = asn_parse_int(data, &length, &type,
(long *)&pdu->errstat, sizeof(pdu->errstat));
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
// get the error index
data = asn_parse_int(data, &length, &type,
(long *)&pdu->errindex, sizeof(pdu->errindex));
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
}
else
{ // is a trap
// get the enterprise
pdu->enterprise_length = ASN_MAX_NAME_LEN;
data = asn_parse_objid(data, &length, &type,
objid, &pdu->enterprise_length);
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
pdu->enterprise = (oid *)malloc(pdu->enterprise_length * sizeof(oid));
memcpy((char *)pdu->enterprise,(char *)objid,
pdu->enterprise_length * sizeof(oid));
// get source address
data = asn_parse_string(data, &length, &type,
(unsigned char *)&pdu->agent_addr.sin_addr.s_addr,
&four);
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
// get trap type
long dummy = 0;
data = asn_parse_int(data, &length, &type, &dummy, sizeof(dummy));
pdu->trap_type = dummy;
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
// trap type
dummy = 0;
data = asn_parse_int(data, &length, &type, &dummy, sizeof(dummy));
pdu->specific_type = dummy;
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
// timestamp
data = asn_parse_unsigned_int(data, &length, &type,
&pdu->time, sizeof(pdu->time));
if (data == NULL) return SNMP_CLASS_ASN1ERROR;
}
return SNMP_CLASS_SUCCESS;
}
// parse a pdu
int snmp_parse( struct snmp_pdu *pdu,
unsigned char *data, int data_length,
unsigned char *community_name,
int &community_len,
snmp_version &spp_version)
{
long version = -1;
// authenticates message and returns length if valid
data = snmp_auth_parse(data, &data_length,
community_name, &community_len,
&version);
if (data == NULL)
return SNMP_CLASS_ASN1ERROR;
if(version != SNMP_VERSION_1 && version != SNMP_VERSION_2C ) {
ASNERROR("Wrong version");
return SNMP_CLASS_BADVERSION;
}
spp_version = (snmp_version) version;
int res = snmp_parse_data_pdu(pdu, data, data_length);
if (res != SNMP_CLASS_SUCCESS)
return res;
return snmp_parse_vb(pdu, data, data_length);
}
#ifdef _SNMPv3
// Parse the field HeaderData of a SNMPv3 message and return the values.
unsigned char *asn1_parse_header_data(unsigned char *buf, int *buf_len,
long *msg_id, long *msg_max_size,
unsigned char *msg_flags,
long *msg_security_model)
{
unsigned char *buf_ptr = buf;
int length = *buf_len;
unsigned char type;
buf = asn_parse_header( buf, &length, &type);
if (!buf)
{
debugprintf(0, "Parse error in header HeaderData");
return 0;
}
if (type != (ASN_SEQ_CON)){
debugprintf(0, "wrong type in header of msgHeaderData");
return 0;
}
buf = asn_parse_int(buf, &length, &type, msg_id, sizeof(*msg_id));
if (!buf){
debugprintf(0, "Parse error: msg_id");
return 0;
}
buf = asn_parse_int(buf, &length,
&type, msg_max_size, sizeof(*msg_max_size));
if (!buf){
debugprintf(0, "Parse error: msg_max_size");
return 0;
}
int dummy = 1;
buf = asn_parse_string( buf, &length, &type, msg_flags, &dummy);
if ((dummy !=1) || (!buf)) {
debugprintf(0, "Parse error: msg_flags");
return 0;
}
buf = asn_parse_int(buf, &length, &type,
msg_security_model, sizeof(*msg_security_model));
if (!buf){
debugprintf(0, "Parse error: msg_security_model");
return 0;
}
if (length) {
debugprintf(0, "Parse error: wrong length in header of HeaderData");
return 0;
}
debugprintf(3, "Parsed HeaderData: globalDataLength(0x%x), msg_id(0x%lx), "
"msg_max_size(0x%lx), msg_flags(0x%x), msg_security_model(0x%lx)",
length, *msg_id, *msg_max_size, *msg_flags, *msg_security_model);
*buf_len -= SAFE_INT_CAST(buf - buf_ptr);
return buf;
}
// Encode the given values for the HeaderData into the buffer.
unsigned char *asn1_build_header_data(unsigned char *outBuf, int *maxLength,
long msgID,
long maxMessageSize,
unsigned char msgFlags,
long securityModel)
{
unsigned char buf[MAXLENGTH_GLOBALDATA];
unsigned char *bufPtr = (unsigned char*)&buf;
unsigned char *outBufPtr = outBuf;
int length = *maxLength;
int totalLength;
#ifdef INVALID_MAXMSGSIZE
debugprintf(-10, "\nWARNING: Using constant MaxMessageSize!\n");
maxMessageSize = 65535;
#endif
debugprintf(3, "Coding msgID(0x%lx), maxMessageSize(0x%lx), "
"msgFlags(0x%x), securityModel(0x%lx)",
msgID, maxMessageSize, msgFlags, securityModel);
bufPtr = asn_build_int(bufPtr, &length,
(unsigned char)(ASN_UNI_PRIV | ASN_INTEGER),
(long *)&msgID, sizeof(msgID));
if (bufPtr == NULL){
debugprintf(0, "asn_build_header_data: Error coding msgID");
return NULL;
}
bufPtr = asn_build_int(bufPtr, &length,
(unsigned char)(ASN_UNI_PRIV | ASN_INTEGER),
(long *)&maxMessageSize, sizeof(maxMessageSize));
if (bufPtr == NULL){
debugprintf(0, "asn_build_header_data: Error coding maxMessageSize");
return NULL;
}
bufPtr = asn_build_string(bufPtr, &length,
(unsigned char)(ASN_UNI_PRIV | ASN_OCTET_STR),
(unsigned char*)&msgFlags, 1);
if (bufPtr == NULL){
debugprintf(0, "asn_build_header_data: Error coding msgFlags");
return NULL;
}
bufPtr = asn_build_int(bufPtr, &length,
(unsigned char)(ASN_UNI_PRIV | ASN_INTEGER),
(long *)&securityModel, sizeof(securityModel));
if (bufPtr == NULL){
debugprintf(0, "asn_build_header_data: Error coding securityModel");
return NULL;
}
totalLength = SAFE_INT_CAST(bufPtr - (unsigned char*)&buf);
debugprintf(3, "Coding sequence (headerdata), length = 0x%x", totalLength);
outBufPtr = asn_build_sequence(outBufPtr, maxLength,
(unsigned char)(ASN_SEQ_CON),
totalLength);
if (outBufPtr == NULL) {
debugprintf(0, "asn_build_header_data: Error coding seq headerdata");
return NULL;
}
if (*maxLength < totalLength) {
debugprintf(0, "asn_build_header_data: Length error");
return NULL;
}
memcpy(outBufPtr, (unsigned char*)&buf, totalLength);
outBufPtr += totalLength;
*maxLength -= totalLength;
debugprintf(21, "bufHeaderData:");
debughexprintf(21, outBuf, SAFE_INT_CAST(outBufPtr - outBuf));
return outBufPtr;
}
#endif
// Parse the ScopedPDU and return the encoded values.
unsigned char *asn1_parse_scoped_pdu(
unsigned char *scoped_pdu, int *scoped_pdu_len,
unsigned char *context_engine_id, int *context_engine_id_len,
unsigned char *context_name, int *context_name_len )
{
unsigned char type;
scoped_pdu = asn_parse_header( scoped_pdu, scoped_pdu_len, &type);
if (!scoped_pdu) {
debugprintf(0, "Parse error: Wrong header in scoped_pdu.");
return 0;
}
if (type != (ASN_SEQ_CON)){
debugprintf(0, "Parse error: Wrong header type in scoped_pdu.");
return 0;
}
scoped_pdu = asn_parse_string( scoped_pdu, scoped_pdu_len, &type,
context_engine_id, context_engine_id_len);
if (!scoped_pdu){
debugprintf(0, "Parse error: context_engine_id");
return 0;
}
scoped_pdu = asn_parse_string( scoped_pdu, scoped_pdu_len, &type,
context_name, context_name_len);
if (!scoped_pdu){
debugprintf(0, "mpParseScopedPDU: bad parse of context_name");
return 0;
}
debugprintf(3, "Parsed scoped_pdu: context_engine_id length(0x%x), "
"context_name length(0x%x)",
*context_engine_id_len, *context_name_len);
return scoped_pdu;
}
// Encode the given values for the scopedPDU into the buffer.
unsigned char *asn1_build_scoped_pdu(
unsigned char *outBuf, int *max_len,
unsigned char *contextEngineID, long contextEngineIDLength,
unsigned char *contextName, long contextNameLength,
unsigned char *data, long dataLength)
{
Buffer buffer(MAX_SNMP_PACKET);
unsigned char *bufPtr = buffer.get_ptr();
unsigned char *outBufPtr = outBuf;
long bufLength = 0;
LOG_BEGIN(DEBUG_LOG | 10);
LOG("ASN1: coding (context engine id) (context name)");
LOG(OctetStr(contextEngineID, contextEngineIDLength).get_printable());
LOG(OctetStr(contextName, contextNameLength).get_printable());
LOG_END;
bufPtr = asn_build_string(bufPtr, max_len,
(unsigned char)(ASN_UNI_PRIV | ASN_OCTET_STR),
contextEngineID, contextEngineIDLength);
if (!bufPtr)
{
LOG_BEGIN(ERROR_LOG | 1);
LOG("ASN1: Error encoding contextEngineID");
LOG_END;
return 0;
}
bufPtr = asn_build_string(bufPtr, max_len,
(unsigned char)(ASN_UNI_PRIV | ASN_OCTET_STR),
contextName, contextNameLength);
if (!bufPtr)
{
LOG_BEGIN(ERROR_LOG | 1);
LOG("ASN1: Error encoding contextName");
LOG_END;
return 0;
}
bufLength = SAFE_INT_CAST(bufPtr - buffer.get_ptr());
memcpy((char *)bufPtr, (char *)data, dataLength);
bufLength += dataLength;
LOG_BEGIN(DEBUG_LOG | 10);
LOG("ASN1: Encoding scoped PDU sequence (len)");
LOG(bufLength);
LOG_END;
outBufPtr = asn_build_sequence(outBufPtr, max_len,
(unsigned char)(ASN_SEQ_CON),
bufLength);
if (!outBufPtr)
{
LOG_BEGIN(ERROR_LOG | 1);
LOG("ASN1: Error encoding scopedPDU sequence");
LOG_END;
return 0;
}
memcpy(outBufPtr, buffer.get_ptr(), bufLength);
outBufPtr += bufLength;
#ifdef __DEBUG
LOG_BEGIN(DEBUG_LOG | 15);
LOG("ASN1: Result of build_scoped_pdu (len) (data)");
LOG(outBufPtr - outBuf);
LOG(OctetStr(outBuf, outBufPtr - outBuf).get_printable_hex());
LOG_END;
#endif
return outBufPtr;
}
#ifdef SNMP_PP_NAMESPACE
}; // end of namespace Snmp_pp
#endif