asn1.c

/*
 * 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 <net-snmp/net-snmp-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_NETINET_IN_H
#include <netinet/in.h>
#endif

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

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

#include <net-snmp/output_api.h>
#include <net-snmp/utilities.h>

#include <net-snmp/library/asn1.h>
#include <net-snmp/library/int64.h>
#include <net-snmp/library/mib.h>

#ifndef NULL
#define NULL    0
#endif

#include <net-snmp/library/snmp_api.h>

#ifndef INT32_MAX
#   define INT32_MAX 2147483647
#endif

#ifndef INT32_MIN
#   define INT32_MIN (0 - INT32_MAX - 1)
#endif


#if SIZEOF_LONG == 4
#  define CHECK_OVERFLOW_S(x,y)
#  define CHECK_OVERFLOW_U(x,y)
#else
#  define CHECK_OVERFLOW_S(x,y) do {                                    \
        if (x > INT32_MAX) {                                            \
            DEBUGMSG(("asn","truncating signed value %ld to 32 bits (%d)\n",(long)(x),y)); \
            x &= 0xffffffff;                                            \
        } else if (x < INT32_MIN) {                                     \
            DEBUGMSG(("asn","truncating signed value %ld to 32 bits (%d)\n",(long)(x),y)); \
            x = 0 - (x & 0xffffffff);                                   \
        }                                                               \
    } while(0)

#  define CHECK_OVERFLOW_U(x,y) do {                                    \
        if (x > UINT32_MAX) {                                           \
            x &= 0xffffffff;                                            \
            DEBUGMSG(("asn","truncating unsigned value to 32 bits (%d)\n",y)); \
        }                                                               \
    } while(0)
#endif

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

    snprintf(ebuf, sizeof(ebuf),
            "%s size %lu: s/b %lu", str,
            (unsigned long)wrongsize, (unsigned long)rightsize);
    ebuf[ sizeof(ebuf)-1 ] = 0;
    ERROR_MSG(ebuf);
}

static
    void
_asn_type_err(const char *str, int wrongtype)
{
    char            ebuf[128];

    snprintf(ebuf, sizeof(ebuf), "%s type %d", str, wrongtype);
    ebuf[ sizeof(ebuf)-1 ] = 0;
    ERROR_MSG(ebuf);
}

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

    snprintf(ebuf, sizeof(ebuf),
            "%s length %lu too large: exceeds %lu", str,
            (unsigned long)wrongsize, (unsigned long)rightsize);
    ebuf[ sizeof(ebuf)-1 ] = 0;
    ERROR_MSG(ebuf);
}

static
    int
_asn_parse_length_check(const char *str,
                        const u_char * bufp, const 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 (plen > 0x7fffffff || header_len > 0x7fffffff ||
        ((size_t) plen + header_len) > dlen) {
        snprintf(ebuf, sizeof(ebuf),
                "%s: message overflow: %d len + %d delta > %d len",
                str, (int) plen, (int) header_len, (int) dlen);
        ebuf[ sizeof(ebuf)-1 ] = 0;
        ERROR_MSG(ebuf);
        return 1;
    }
    return 0;
}


static
    int
_asn_build_header_check(const char *str, const u_char * data,
                        size_t datalen, size_t typedlen)
{
    char            ebuf[128];

    if (data == NULL) {
        /*
         * error message is set 
         */
        return 1;
    }
    if (datalen < typedlen) {
        snprintf(ebuf, sizeof(ebuf),
                "%s: bad header, length too short: %lu < %lu", str,
                (unsigned long)datalen, (unsigned long)typedlen);
        ebuf[ sizeof(ebuf)-1 ] = 0;
        ERROR_MSG(ebuf);
        return 1;
    }
    return 0;
}

static
    int
_asn_realloc_build_header_check(const char *str,
                                u_char ** pkt,
                                const size_t * pkt_len, size_t typedlen)
{
    char            ebuf[128];

    if (pkt == NULL || *pkt == NULL) {
        /*
         * Error message is set.  
         */
        return 1;
    }

    if (*pkt_len < typedlen) {
        snprintf(ebuf, sizeof(ebuf),
                "%s: bad header, length too short: %lu < %lu", str,
                (unsigned long)*pkt_len, (unsigned long)typedlen);
        ebuf[ sizeof(ebuf)-1 ] = 0;
        ERROR_MSG(ebuf);
        return 1;
    }
    return 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, size_t asn_length, u_char datum)
{
    char            ebuf[128];

    if (asn_length < 1) {
        snprintf(ebuf, sizeof(ebuf),
                "%s: length %d too small", str, (int) asn_length);
        ebuf[ sizeof(ebuf)-1 ] = 0;
        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;
}

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++;
    if (*type != ASN_INTEGER) {
        _asn_type_err(errpre, *type);
        return NULL;
    }

    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("recv", data, bufp - data + asn_length);

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

    CHECK_OVERFLOW_S(value,1);

    DEBUGMSG(("dumpv_recv", "  Integer:\t%ld (0x%.2lX)\n", value, value));

    *intp = value;
    return bufp;
}


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++;
    if (*type != ASN_COUNTER && *type != ASN_GAUGE && *type != ASN_TIMETICKS
            && *type != ASN_UINTEGER) {
        _asn_type_err(errpre, *type);
        return NULL;
    }
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check
        (errpre, bufp, data, asn_length, *datalength))
        return NULL;

    if ((asn_length > (intsize + 1)) ||
        ((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("recv", data, bufp - data + asn_length);

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

    CHECK_OVERFLOW_U(value,2);

    DEBUGMSG(("dumpv_recv", "  UInteger:\t%ld (0x%.2lX)\n", value, value));

    *intp = value;
    return bufp;
}


u_char         *
asn_build_int(u_char * data,
           size_t * datalength, u_char type, const long *intp, size_t intsize)
{
    /*
     * ASN.1 integer ::= 0x02 asnlength byte {byte}*
     */
    static const char *errpre = "build int";
    register long   integer;
    register u_long mask;
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif

    if (intsize != sizeof(long)) {
        _asn_size_err(errpre, intsize, sizeof(long));
        return NULL;
    }
    integer = *intp;
    CHECK_OVERFLOW_S(integer,3);
    /*
     * 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 = ((u_long) 0x1FF) << ((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 (_asn_build_header_check(errpre, data, *datalength, intsize))
        return NULL;

    *datalength -= intsize;
    mask = ((u_long) 0xFF) << (8 * (sizeof(long) - 1));
    /*
     * mask is 0xFF000000 on a big-endian machine 
     */
    while (intsize--) {
        *data++ = (u_char) ((integer & mask) >> (8 * (sizeof(long) - 1)));
        integer <<= 8;
    }
    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGMSG(("dumpv_send", "  Integer:\t%ld (0x%.2lX)\n", *intp, *intp));
    return data;
}



u_char         *
asn_build_unsigned_int(u_char * data,
                       size_t * datalength,
                       u_char type, const u_long * intp, size_t intsize)
{
    /*
     * ASN.1 integer ::= 0x02 asnlength byte {byte}*
     */
    static const char *errpre = "build uint";
    register u_long integer;
    register u_long mask;
    int             add_null_byte = 0;
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif

    if (intsize != sizeof(long)) {
        _asn_size_err(errpre, intsize, sizeof(long));
        return NULL;
    }
    integer = *intp;
    CHECK_OVERFLOW_U(integer,4);

    mask = ((u_long) 0xFF) << (8 * (sizeof(long) - 1));
    /*
     * mask is 0xFF000000 on a big-endian machine 
     */
    if ((u_char) ((integer & 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.
         */
        mask = ((u_long) 0x1FF) << ((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 (_asn_build_header_check(errpre, data, *datalength, intsize))
        return NULL;

    *datalength -= intsize;
    if (add_null_byte == 1) {
        *data++ = '\0';
        intsize--;
    }
    mask = ((u_long) 0xFF) << (8 * (sizeof(long) - 1));
    /*
     * mask is 0xFF000000 on a big-endian machine 
     */
    while (intsize--) {
        *data++ = (u_char) ((integer & mask) >> (8 * (sizeof(long) - 1)));
        integer <<= 8;
    }
    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGMSG(("dumpv_send", "  UInteger:\t%ld (0x%.2lX)\n", *intp, *intp));
    return data;
}


u_char         *
asn_parse_string(u_char * data,
                 size_t * datalength,
                 u_char * type, u_char * str, size_t * strlength)
{
    static const char *errpre = "parse string";
    u_char         *bufp = data;
    u_long          asn_length;

    *type = *bufp++;
    if (*type != ASN_OCTET_STR && *type != ASN_IPADDRESS && *type != ASN_OPAQUE
            && *type != ASN_NSAP) {
        _asn_type_err(errpre, *type);
        return NULL;
    }

    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check
        (errpre, bufp, data, asn_length, *datalength)) {
        return NULL;
    }

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

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

    memmove(str, bufp, asn_length);
    if (*strlength > asn_length)
        str[asn_length] = 0;
    *strlength = asn_length;
    *datalength -= asn_length + (bufp - data);

    DEBUGIF("dumpv_recv") {
        u_char         *buf = (u_char *) malloc(1 + asn_length);
        size_t          l = (buf != NULL) ? (1 + asn_length) : 0, ol = 0;

        if (sprint_realloc_asciistring
            (&buf, &l, &ol, 1, str, asn_length)) {
            DEBUGMSG(("dumpv_recv", "  String:\t%s\n", buf));
        } else {
            if (buf == NULL) {
                DEBUGMSG(("dumpv_recv", "  String:\t[TRUNCATED]\n"));
            } else {
                DEBUGMSG(("dumpv_recv", "  String:\t%s [TRUNCATED]\n",
                          buf));
            }
        }
        if (buf != NULL) {
            free(buf);
        }
    }

    return bufp + asn_length;
}


u_char         *
asn_build_string(u_char * data,
                 size_t * datalength,
                 u_char type, const u_char * str, size_t 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.
     */
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif
    data = asn_build_header(data, datalength, type, strlength);
    if (_asn_build_header_check
        ("build string", data, *datalength, strlength))
        return NULL;

    if (strlength) {
        if (str == NULL) {
            memset(data, 0, strlength);
        } else {
            memmove(data, str, strlength);
        }
    }
    *datalength -= strlength;
    DEBUGDUMPSETUP("send", initdatap, data - initdatap + strlength);
    DEBUGIF("dumpv_send") {
        u_char         *buf = (u_char *) malloc(1 + strlength);
        size_t          l = (buf != NULL) ? (1 + strlength) : 0, ol = 0;

        if (sprint_realloc_asciistring
            (&buf, &l, &ol, 1, str, strlength)) {
            DEBUGMSG(("dumpv_send", "  String:\t%s\n", buf));
        } else {
            if (buf == NULL) {
                DEBUGMSG(("dumpv_send", "  String:\t[TRUNCATED]\n"));
            } else {
                DEBUGMSG(("dumpv_send", "  String:\t%s [TRUNCATED]\n",
                          buf));
            }
        }
        if (buf != NULL) {
            free(buf);
        }
    }
    return data + strlength;
}



u_char         *
asn_parse_header(u_char * data, size_t * datalength, u_char * type)
{
    register u_char *bufp;
    u_long          asn_length;

    if (!data || !datalength || !type) {
        ERROR_MSG("parse header: NULL pointer");
        return NULL;
    }
    bufp = data;
    /*
     * this only works on data types < 30, i.e. no extension octets 
     */
    if (IS_EXTENSION_ID(*bufp)) {
        ERROR_MSG("can't process ID >= 30");
        return NULL;
    }
    *type = *bufp;
    bufp = asn_parse_length(bufp + 1, &asn_length);

    if (_asn_parse_length_check
        ("parse header", bufp, data, asn_length, *datalength))
        return NULL;

#ifdef DUMP_PRINT_HEADERS
    DEBUGDUMPSETUP("recv", data, (bufp - data));
    DEBUGMSG(("dumpv_recv", "  Header: 0x%.2X, len = %d (0x%X)\n", *data,
              asn_length, asn_length));
#else
    /*
     * DEBUGMSGHEXTLI(("recv",data,(bufp-data)));
     * DEBUGMSG(("dumpH_recv","\n"));
     */
#endif

#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES

    if ((*type == ASN_OPAQUE) && (*bufp == ASN_OPAQUE_TAG1)) {

        /*
         * check if 64-but counter 
         */
        switch (*(bufp + 1)) {
        case ASN_OPAQUE_COUNTER64:
        case ASN_OPAQUE_U64:
        case ASN_OPAQUE_FLOAT:
        case ASN_OPAQUE_DOUBLE:
        case ASN_OPAQUE_I64:
            *type = *(bufp + 1);
            break;

        default:
            /*
             * just an Opaque 
             */
            *datalength = (int) asn_length;
            return bufp;
        }
        /*
         * value is encoded as special format 
         */
        bufp = asn_parse_length(bufp + 2, &asn_length);
        if (_asn_parse_length_check("parse opaque header", bufp, data,
                                    asn_length, *datalength))
            return NULL;
    }
#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */

    *datalength = (int) asn_length;

    return bufp;
}

u_char         *
asn_parse_sequence(u_char * data, size_t * datalength, u_char * type, u_char expected_type,     /* must be this type */
                   const char *estr)
{                               /* error message prefix */
    data = asn_parse_header(data, datalength, type);
    if (data && (*type != expected_type)) {
        char            ebuf[128];
        snprintf(ebuf, sizeof(ebuf),
                 "%s header type %02X: s/b %02X", estr,
                (u_char) * type, (u_char) expected_type);
        ebuf[ sizeof(ebuf)-1 ] = 0;
        ERROR_MSG(ebuf);
        return NULL;
    }
    return data;
}



u_char         *
asn_build_header(u_char * data,
                 size_t * datalength, u_char type, size_t length)
{
    char            ebuf[128];

    if (*datalength < 1) {
        snprintf(ebuf, sizeof(ebuf),
                "bad header length < 1 :%lu, %lu",
                (unsigned long)*datalength, (unsigned long)length);
        ebuf[ sizeof(ebuf)-1 ] = 0;
        ERROR_MSG(ebuf);
        return NULL;
    }
    *data++ = type;
    (*datalength)--;
    return asn_build_length(data, datalength, length);
}

u_char         *
asn_build_sequence(u_char * data,
                   size_t * datalength, u_char type, size_t length)
{
    static const char *errpre = "build seq";
    char            ebuf[128];

    if (*datalength < 4) {
        snprintf(ebuf, sizeof(ebuf),
                "%s: length %d < 4: PUNT", errpre,
                (int) *datalength);
        ebuf[ sizeof(ebuf)-1 ] = 0;
        ERROR_MSG(ebuf);
        return NULL;
    }
    *datalength -= 4;
    *data++ = type;
    *data++ = (u_char) (0x02 | ASN_LONG_LEN);
    *data++ = (u_char) ((length >> 8) & 0xFF);
    *data++ = (u_char) (length & 0xFF);
    return data;
}

u_char         *
asn_parse_length(u_char * data, u_long * length)
{
    static const char *errpre = "parse length";
    char            ebuf[128];
    register u_char lengthbyte;

    if (!data || !length) {
        ERROR_MSG("parse length: NULL pointer");
        return NULL;
    }
    lengthbyte = *data;

    if (lengthbyte & ASN_LONG_LEN) {
        lengthbyte &= ~ASN_LONG_LEN;    /* turn MSb off */
        if (lengthbyte == 0) {
            snprintf(ebuf, sizeof(ebuf),
                     "%s: indefinite length not supported", errpre);
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return NULL;
        }
        if (lengthbyte > sizeof(long)) {
            snprintf(ebuf, sizeof(ebuf),
                    "%s: data length %d > %lu not supported", errpre,
                    lengthbyte, (unsigned long)sizeof(long));
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return NULL;
        }
        data++;
        *length = 0;            /* protect against short lengths */
        while (lengthbyte--) {
            *length <<= 8;
            *length |= *data++;
        }
        if ((long) *length < 0) {
            snprintf(ebuf, sizeof(ebuf),
                     "%s: negative data length %ld\n", errpre,
                     (long) *length);
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return NULL;
        }
        return data;
    } else {                    /* short asnlength */
        *length = (long) lengthbyte;
        return data + 1;
    }
}

u_char         *
asn_build_length(u_char * data, size_t * datalength, size_t length)
{
    static const char *errpre = "build length";
    char            ebuf[128];

    u_char         *start_data = data;

    /*
     * no indefinite lengths sent 
     */
    if (length < 0x80) {
        if (*datalength < 1) {
            snprintf(ebuf, sizeof(ebuf),
                    "%s: bad length < 1 :%lu, %lu", errpre,
                    (unsigned long)*datalength, (unsigned long)length);
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return NULL;
        }
        *data++ = (u_char) length;
    } else if (length <= 0xFF) {
        if (*datalength < 2) {
            snprintf(ebuf, sizeof(ebuf),
                    "%s: bad length < 2 :%lu, %lu", errpre,
                    (unsigned long)*datalength, (unsigned long)length);
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return NULL;
        }
        *data++ = (u_char) (0x01 | ASN_LONG_LEN);
        *data++ = (u_char) length;
    } else {                    /* 0xFF < length <= 0xFFFF */
        if (*datalength < 3) {
            snprintf(ebuf, sizeof(ebuf),
                    "%s: bad length < 3 :%lu, %lu", errpre,
                    (unsigned long)*datalength, (unsigned long)length);
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return NULL;
        }
        *data++ = (u_char) (0x02 | ASN_LONG_LEN);
        *data++ = (u_char) ((length >> 8) & 0xFF);
        *data++ = (u_char) (length & 0xFF);
    }
    *datalength -= (data - start_data);
    return data;

}

u_char         *
asn_parse_objid(u_char * data,
                size_t * datalength,
                u_char * type, oid * objid, size_t * objidlength)
{
    static const char *errpre = "parse objid";
    /*
     * ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}*
     * subidentifier ::= {leadingbyte}* lastbyte
     * leadingbyte ::= 1 7bitvalue
     * lastbyte ::= 0 7bitvalue
     */
    register u_char *bufp = data;
    register oid   *oidp = objid + 1;
    register u_long subidentifier;
    register long   length;
    u_long          asn_length;
    size_t          original_length = *objidlength;

    *type = *bufp++;
    if (*type != ASN_OBJECT_ID) {
        _asn_type_err(errpre, *type);
        return NULL;
    }
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check("parse objid", bufp, data,
                                asn_length, *datalength))
        return NULL;

    *datalength -= (int) asn_length + (bufp - data);

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

    /*
     * 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) + (*(u_char *) bufp & ~ASN_BIT8);
            length--;
        } while ((*(u_char *) bufp++ & ASN_BIT8) && (length > 0));        /* last byte has high bit clear */

        if (length == 0) {
            u_char *last_byte = bufp - 1;
            if (*last_byte & ASN_BIT8) {
                /* last byte has high bit set -> wrong BER encoded OID */
                ERROR_MSG("subidentifier syntax error");
                return NULL;
            }
        }
#if defined(EIGHTBIT_SUBIDS) || (SIZEOF_LONG != 4)
        if (subidentifier > (u_long) MAX_SUBID) {
            ERROR_MSG("subidentifier too large");
            return NULL;
        }
#endif
        *oidp++ = (oid) subidentifier;
    }

    if (0 != length) {
        ERROR_MSG("OID length exceeds buffer size");
        *objidlength = original_length;
        return NULL;
    }

    /*
     * 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 = (u_long) objid[1];
    if (subidentifier == 0x2B) {
        objid[0] = 1;
        objid[1] = 3;
    } else {
        if (subidentifier < 40) {
            objid[0] = 0;
            objid[1] = subidentifier;
        } else if (subidentifier < 80) {
            objid[0] = 1;
            objid[1] = subidentifier - 40;
        } else {
            objid[0] = 2;
            objid[1] = subidentifier - 80;
        }
    }

    *objidlength = (int) (oidp - objid);

    DEBUGMSG(("dumpv_recv", "  ObjID: "));
    DEBUGMSGOID(("dumpv_recv", objid, *objidlength));
    DEBUGMSG(("dumpv_recv", "\n"));
    return bufp;
}

u_char         *
asn_build_objid(u_char * data,
                size_t * datalength,
                u_char type, oid * objid, size_t objidlength)
{
    /*
     * ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}*
     * subidentifier ::= {leadingbyte}* lastbyte
     * leadingbyte ::= 1 7bitvalue
     * lastbyte ::= 0 7bitvalue
     */
    size_t          asnlength;
    register oid   *op = objid;
    u_char          objid_size[MAX_OID_LEN];
    register u_long objid_val;
    u_long          first_objid_val;
    register int    i;
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif

    /*
     * check if there are at least 2 sub-identifiers 
     */
    if (objidlength == 0) {
        /*
         * there are not, so make OID have two with value of zero 
         */
        objid_val = 0;
        objidlength = 2;
    } else if (objid[0] > 2) {
        ERROR_MSG("build objid: bad first subidentifier");
        return NULL;
    } else if (objidlength == 1) {
        /*
         * encode the first value 
         */
        objid_val = (op[0] * 40);
        objidlength = 2;
        op++;
    } else {
        /*
         * combine the first two values 
         */
        if ((op[1] > 40) &&
            (op[0] < 2)) {
            ERROR_MSG("build objid: bad second subidentifier");
            return NULL;
        }
        objid_val = (op[0] * 40) + op[1];
        op += 2;
    }
    first_objid_val = objid_val;

    /*
     * ditch illegal calls now 
     */
    if (objidlength > MAX_OID_LEN)
        return NULL;

    /*
     * calculate the number of bytes needed to store the encoded value 
     */
    for (i = 1, asnlength = 0;;) {

        CHECK_OVERFLOW_U(objid_val,5);
        if (objid_val < (unsigned) 0x80) {
            objid_size[i] = 1;
            asnlength += 1;
        } else if (objid_val < (unsigned) 0x4000) {
            objid_size[i] = 2;
            asnlength += 2;
        } else if (objid_val < (unsigned) 0x200000) {
            objid_size[i] = 3;
            asnlength += 3;
        } else if (objid_val < (unsigned) 0x10000000) {
            objid_size[i] = 4;
            asnlength += 4;
        } else {
            objid_size[i] = 5;
            asnlength += 5;
        }
        i++;
        if (i >= (int) objidlength)
            break;
        objid_val = *op++;      /* XXX - doesn't handle 2.X (X > 40) */
    }

    /*
     * store the ASN.1 tag and length 
     */
    data = asn_build_header(data, datalength, type, asnlength);
    if (_asn_build_header_check
        ("build objid", data, *datalength, asnlength))
        return NULL;

    /*
     * store the encoded OID value 
     */
    for (i = 1, objid_val = first_objid_val, op = objid + 2;
         i < (int) objidlength; i++) {
        if (i != 1) {
            objid_val = *op++;
#if SIZEOF_LONG != 4
            if (objid_val > 0xffffffff) /* already logged warning above */
                objid_val &= 0xffffffff;
#endif
        }
        switch (objid_size[i]) {
        case 1:
            *data++ = (u_char) objid_val;
            break;

        case 2:
            *data++ = (u_char) ((objid_val >> 7) | 0x80);
            *data++ = (u_char) (objid_val & 0x07f);
            break;

        case 3:
            *data++ = (u_char) ((objid_val >> 14) | 0x80);
            *data++ = (u_char) ((objid_val >> 7 & 0x7f) | 0x80);
            *data++ = (u_char) (objid_val & 0x07f);
            break;

        case 4:
            *data++ = (u_char) ((objid_val >> 21) | 0x80);
            *data++ = (u_char) ((objid_val >> 14 & 0x7f) | 0x80);
            *data++ = (u_char) ((objid_val >> 7 & 0x7f) | 0x80);
            *data++ = (u_char) (objid_val & 0x07f);
            break;

        case 5:
            *data++ = (u_char) ((objid_val >> 28) | 0x80);
            *data++ = (u_char) ((objid_val >> 21 & 0x7f) | 0x80);
            *data++ = (u_char) ((objid_val >> 14 & 0x7f) | 0x80);
            *data++ = (u_char) ((objid_val >> 7 & 0x7f) | 0x80);
            *data++ = (u_char) (objid_val & 0x07f);
            break;
        }
    }

    /*
     * return the length and data ptr 
     */
    *datalength -= asnlength;
    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGMSG(("dumpv_send", "  ObjID: "));
    DEBUGMSGOID(("dumpv_send", objid, objidlength));
    DEBUGMSG(("dumpv_send", "\n"));
    return data;
}

u_char         *
asn_parse_null(u_char * data, size_t * datalength, u_char * type)
{
    /*
     * ASN.1 null ::= 0x05 0x00
     */
    register u_char *bufp = data;
    u_long          asn_length;

    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (bufp == NULL) {
        ERROR_MSG("parse null: bad length");
        return NULL;
    }
    if (asn_length != 0) {
        ERROR_MSG("parse null: malformed ASN.1 null");
        return NULL;
    }

    *datalength -= (bufp - data);

    DEBUGDUMPSETUP("recv", data, bufp - data);
    DEBUGMSG(("dumpv_recv", "  NULL\n"));

    return bufp + asn_length;
}


u_char         *
asn_build_null(u_char * data, size_t * datalength, u_char type)
{
    /*
     * ASN.1 null ::= 0x05 0x00
     */
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif
    data = asn_build_header(data, datalength, type, 0);
    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGMSG(("dumpv_send", "  NULL\n"));
    return data;
}

u_char         *
asn_parse_bitstring(u_char * data,
                    size_t * datalength,
                    u_char * type, u_char * str, size_t * strlength)
{
    /*
     * bitstring ::= 0x03 asnlength unused {byte}*
     */
    static const char *errpre = "parse bitstring";
    register u_char *bufp = data;
    u_long          asn_length;

    *type = *bufp++;
    if (*type != ASN_BIT_STR) {
        _asn_type_err(errpre, *type);
        return NULL;
    }
    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 > *strlength) {
        _asn_length_err(errpre, (size_t) asn_length, *strlength);
        return NULL;
    }
    if (_asn_bitstring_check(errpre, asn_length, *bufp))
        return NULL;

    DEBUGDUMPSETUP("recv", data, bufp - data);
    DEBUGMSG(("dumpv_recv", "  Bitstring: "));
    DEBUGMSGHEX(("dumpv_recv", data, asn_length));
    DEBUGMSG(("dumpv_recv", "\n"));

    memmove(str, bufp, asn_length);
    *strlength = (int) asn_length;
    *datalength -= (int) asn_length + (bufp - data);
    return bufp + asn_length;
}


u_char         *
asn_build_bitstring(u_char * data,
                    size_t * datalength,
                    u_char type, const u_char * str, size_t strlength)
{
    /*
     * ASN.1 bit string ::= 0x03 asnlength unused {byte}*
     */
    static const char *errpre = "build bitstring";
    if (_asn_bitstring_check
        (errpre, strlength, (u_char)((str) ? *str :  0)))
        return NULL;

    data = asn_build_header(data, datalength, type, strlength);
    if (_asn_build_header_check(errpre, data, *datalength, strlength))
        return NULL;

    if (strlength > 0 && str)
        memmove(data, str, strlength);
    else if (strlength > 0 && !str) {
        ERROR_MSG("no string passed into asn_build_bitstring\n");
        return NULL;
    }

    *datalength -= strlength;
    DEBUGDUMPSETUP("send", data, strlength);
    DEBUGMSG(("dumpv_send", "  Bitstring: "));
    DEBUGMSGHEX(("dumpv_send", data, strlength));
    DEBUGMSG(("dumpv_send", "\n"));
    return data + strlength;
}

u_char         *
asn_parse_unsigned_int64(u_char * data,
                         size_t * datalength,
                         u_char * type,
                         struct counter64 * cp, size_t countersize)
{
    /*
     * ASN.1 integer ::= 0x02 asnlength byte {byte}*
     */
    static const char *errpre = "parse uint64";
    const int       uint64sizelimit = (4 * 2) + 1;
    register u_char *bufp = data;
    u_long          asn_length;
    register u_long low = 0, high = 0;

    if (countersize != sizeof(struct counter64)) {
        _asn_size_err(errpre, countersize, sizeof(struct counter64));
        return NULL;
    }
    *type = *bufp++;
    if (*type != ASN_COUNTER64
#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
            && *type != ASN_OPAQUE_COUNTER64 && *type != ASN_OPAQUE_U64
#endif
            ) {
        _asn_type_err(errpre, *type);
        return NULL;
    }
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check
        (errpre, bufp, data, asn_length, *datalength))
        return NULL;

    DEBUGDUMPSETUP("recv", data, bufp - data);
#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
    /*
     * 64 bit counters as opaque 
     */
    if ((*type == ASN_OPAQUE) &&
        (asn_length <= ASN_OPAQUE_COUNTER64_MX_BER_LEN) &&
        (*bufp == ASN_OPAQUE_TAG1) &&
        ((*(bufp + 1) == ASN_OPAQUE_COUNTER64) ||
         (*(bufp + 1) == ASN_OPAQUE_U64))) {
        /*
         * change type to Counter64 or U64 
         */
        *type = *(bufp + 1);
        /*
         * value is encoded as special format 
         */
        bufp = asn_parse_length(bufp + 2, &asn_length);
        if (_asn_parse_length_check("parse opaque uint64", bufp, data,
                                    asn_length, *datalength))
            return NULL;
    }
#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */
    if (((int) asn_length > uint64sizelimit) ||
        (((int) asn_length == uint64sizelimit) && *bufp != 0x00)) {
        _asn_length_err(errpre, (size_t) asn_length, uint64sizelimit);
        return NULL;
    }
    *datalength -= (int) asn_length + (bufp - data);
    while (asn_length--) {
        high = ((0x00FFFFFF & high) << 8) | ((low & 0xFF000000U) >> 24);
        low = ((low & 0x00FFFFFF) << 8) | *bufp++;
    }

    CHECK_OVERFLOW_U(high,6);
    CHECK_OVERFLOW_U(low,6);

    cp->low = low;
    cp->high = high;

    DEBUGIF("dumpv_recv") {
        char            i64buf[I64CHARSZ + 1];
        printU64(i64buf, cp);
        DEBUGMSG(("dumpv_recv", "Counter64: %s\n", i64buf));
    }

    return bufp;
}


u_char         *
asn_build_unsigned_int64(u_char * data,
                         size_t * datalength,
                         u_char type,
                         const struct counter64 * cp, size_t countersize)
{
    /*
     * ASN.1 integer ::= 0x02 asnlength byte {byte}*
     */

    register u_long low, high;
    register u_long mask, mask2;
    int             add_null_byte = 0;
    size_t          intsize;
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif

    if (countersize != sizeof(struct counter64)) {
        _asn_size_err("build uint64", countersize,
                      sizeof(struct counter64));
        return NULL;
    }
    intsize = 8;
    low = cp->low;
    high = cp->high;

    CHECK_OVERFLOW_U(high,7);
    CHECK_OVERFLOW_U(low,7);

    mask = 0xff000000U;
    if (high & 0x80000000U) {
        /*
         * 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 = 0xff800000U;
        while ((((high & mask2) == 0) || ((high & mask2) == mask2))
               && intsize > 1) {
            intsize--;
            high = ((high & 0x00ffffffu) << 8) | ((low & mask) >> 24);
            low = (low & 0x00ffffffu) << 8;
        }
    }
#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
    /*
     * encode a Counter64 as an opaque (it also works in SNMPv1) 
     */
    /*
     * turn into Opaque holding special tagged value 
     */
    if (type == ASN_OPAQUE_COUNTER64) {
        /*
         * put the tag and length for the Opaque wrapper 
         */
        data = asn_build_header(data, datalength, ASN_OPAQUE, intsize + 3);
        if (_asn_build_header_check
            ("build counter u64", data, *datalength, intsize + 3))
            return NULL;

        /*
         * put the special tag and length 
         */
        *data++ = ASN_OPAQUE_TAG1;
        *data++ = ASN_OPAQUE_COUNTER64;
        *data++ = (u_char) intsize;
        *datalength = *datalength - 3;
    } else
        /*
         * Encode the Unsigned int64 in an opaque 
         */
        /*
         * turn into Opaque holding special tagged value 
         */
    if (type == ASN_OPAQUE_U64) {
        /*
         * put the tag and length for the Opaque wrapper 
         */
        data = asn_build_header(data, datalength, ASN_OPAQUE, intsize + 3);
        if (_asn_build_header_check
            ("build opaque u64", data, *datalength, intsize + 3))
            return NULL;

        /*
         * put the special tag and length 
         */
        *data++ = ASN_OPAQUE_TAG1;
        *data++ = ASN_OPAQUE_U64;
        *data++ = (u_char) intsize;
        *datalength = *datalength - 3;
    } else {
#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */
        data = asn_build_header(data, datalength, type, intsize);
        if (_asn_build_header_check
            ("build uint64", data, *datalength, intsize))
            return NULL;

#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
    }
#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */
    *datalength -= intsize;
    if (add_null_byte == 1) {
        *data++ = '\0';
        intsize--;
    }
    while (intsize--) {
        *data++ = (u_char) (high >> 24);
        high = ((high & 0x00ffffff) << 8) | ((low & mask) >> 24);
        low = (low & 0x00ffffff) << 8;

    }
    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGIF("dumpv_send") {
        char            i64buf[I64CHARSZ + 1];
        printU64(i64buf, cp);
        DEBUGMSG(("dumpv_send", "%s", i64buf));
    }
    return data;
}

#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES


u_char         *
asn_parse_signed_int64(u_char * data,
                       size_t * datalength,
                       u_char * type,
                       struct counter64 * cp, size_t countersize)
{
    static const char *errpre = "parse int64";
    const int       int64sizelimit = (4 * 2) + 1;
    char            ebuf[128];
    register u_char *bufp = data;
    u_long          asn_length;
    register u_int  low = 0, high = 0;

    if (countersize != sizeof(struct counter64)) {
        _asn_size_err(errpre, countersize, sizeof(struct counter64));
        return NULL;
    }
    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check
        (errpre, bufp, data, asn_length, *datalength))
        return NULL;

    DEBUGDUMPSETUP("recv", data, bufp - data);
    if ((*type == ASN_OPAQUE) &&
        (asn_length <= ASN_OPAQUE_COUNTER64_MX_BER_LEN) &&
        (*bufp == ASN_OPAQUE_TAG1) && (*(bufp + 1) == ASN_OPAQUE_I64)) {
        /*
         * change type to Int64 
         */
        *type = *(bufp + 1);
        /*
         * value is encoded as special format 
         */
        bufp = asn_parse_length(bufp + 2, &asn_length);
        if (_asn_parse_length_check("parse opaque int64", bufp, data,
                                    asn_length, *datalength))
            return NULL;
    }
    /*
     * this should always have been true until snmp gets int64 PDU types 
     */
    else {
        snprintf(ebuf, sizeof(ebuf),
                "%s: wrong type: %d, len %d, buf bytes (%02X,%02X)",
                errpre, *type, (int) asn_length, *bufp, *(bufp + 1));
        ebuf[ sizeof(ebuf)-1 ] = 0;
        ERROR_MSG(ebuf);
        return NULL;
    }
    if (((int) asn_length > int64sizelimit) ||
        (((int) asn_length == int64sizelimit) && *bufp != 0x00)) {
        _asn_length_err(errpre, (size_t) asn_length, int64sizelimit);
        return NULL;
    }
    *datalength -= (int) asn_length + (bufp - data);
    if (*bufp & 0x80) {
        low = 0xFFFFFFFFU;   /* first byte bit 1 means start the data with 1s */
        high = 0xFFFFFF;
    }

    while (asn_length--) {
        high = ((0x00FFFFFF & high) << 8) | ((low & 0xFF000000U) >> 24);
        low = ((low & 0x00FFFFFF) << 8) | *bufp++;
    }

    CHECK_OVERFLOW_U(high,8);
    CHECK_OVERFLOW_U(low,8);

    cp->low = low;
    cp->high = high;

    DEBUGIF("dumpv_recv") {
        char            i64buf[I64CHARSZ + 1];
        printI64(i64buf, cp);
        DEBUGMSG(("dumpv_recv", "Integer64: %s\n", i64buf));
    }

    return bufp;
}



u_char         *
asn_build_signed_int64(u_char * data,
                       size_t * datalength,
                       u_char type,
                       const struct counter64 * cp, size_t countersize)
{
    /*
     * ASN.1 integer ::= 0x02 asnlength byte {byte}*
     */

    register u_int  mask, mask2;
    u_long          low;
    long            high; /* MUST be signed because of CHECK_OVERFLOW_S(). */
    size_t          intsize;
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif

    if (countersize != sizeof(struct counter64)) {
        _asn_size_err("build int64", countersize,
                      sizeof(struct counter64));
        return NULL;
    }
    intsize = 8;
    low = cp->low;
    high = cp->high; /* unsigned to signed conversion */

    CHECK_OVERFLOW_S(high,9);
    CHECK_OVERFLOW_U(low,9);

    /*
     * 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 = 0xFF000000U;
    mask2 = 0xFF800000U;
    while ((((high & mask2) == 0) || ((high & mask2) == mask2))
           && intsize > 1) {
        intsize--;
        high = ((high & 0x00ffffff) << 8) | ((low & mask) >> 24);
        low = (low & 0x00ffffff) << 8;
    }
    /*
     * until a real int64 gets incorperated into SNMP, we are going to
     * encode it as an opaque instead.  First, we build the opaque
     * header and then the int64 tag type we use to mark it as an
     * int64 in the opaque string. 
     */
    data = asn_build_header(data, datalength, ASN_OPAQUE, intsize + 3);
    if (_asn_build_header_check
        ("build int64", data, *datalength, intsize + 3))
        return NULL;

    *data++ = ASN_OPAQUE_TAG1;
    *data++ = ASN_OPAQUE_I64;
    *data++ = (u_char) intsize;
    *datalength -= (3 + intsize);

    while (intsize--) {
        *data++ = (u_char) (high >> 24);
        high = ((high & 0x00ffffff) << 8) | ((low & mask) >> 24);
        low = (low & 0x00ffffff) << 8;
    }
    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGIF("dumpv_send") {
        char            i64buf[I64CHARSZ + 1];
        printU64(i64buf, cp);
        DEBUGMSG(("dumpv_send", "%s\n", i64buf));
    }
    return data;
}


u_char         *
asn_parse_float(u_char * data,
                size_t * datalength,
                u_char * type, float *floatp, size_t floatsize)
{
    static const char *errpre = "parse float";
    register u_char *bufp = data;
    u_long          asn_length;
    union {
        float           floatVal;
        long            longVal;
        u_char          c[sizeof(float)];
    } fu;

    if (floatsize != sizeof(float)) {
        _asn_size_err("parse float", floatsize, sizeof(float));
        return NULL;
    }
    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check("parse float", bufp, data,
                                asn_length, *datalength))
        return NULL;

    DEBUGDUMPSETUP("recv", data, bufp - data + asn_length);
    /*
     * the float is encoded as an opaque 
     */
    if ((*type == ASN_OPAQUE) &&
        (asn_length == ASN_OPAQUE_FLOAT_BER_LEN) &&
        (*bufp == ASN_OPAQUE_TAG1) && (*(bufp + 1) == ASN_OPAQUE_FLOAT)) {

        /*
         * value is encoded as special format 
         */
        bufp = asn_parse_length(bufp + 2, &asn_length);
        if (_asn_parse_length_check("parse opaque float", bufp, data,
                                    asn_length, *datalength))
            return NULL;

        /*
         * change type to Float 
         */
        *type = ASN_OPAQUE_FLOAT;
    }

    if (*type != ASN_OPAQUE_FLOAT) {
        _asn_type_err(errpre, *type);
        return NULL;
    }

    if (asn_length != sizeof(float)) {
        _asn_size_err("parse seq float", asn_length, sizeof(float));
        return NULL;
    }

    *datalength -= (int) asn_length + (bufp - data);
    memcpy(&fu.c[0], bufp, asn_length);

    /*
     * correct for endian differences 
     */
    fu.longVal = ntohl(fu.longVal);

    *floatp = fu.floatVal;

    DEBUGMSG(("dumpv_recv", "Opaque float: %f\n", *floatp));
    return bufp;
}

u_char         *
asn_build_float(u_char * data,
                size_t * datalength,
                u_char type, const float *floatp, size_t floatsize)
{
    union {
        float           floatVal;
        int             intVal;
        u_char          c[sizeof(float)];
    } fu;
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif

    if (floatsize != sizeof(float)) {
        _asn_size_err("build float", floatsize, sizeof(float));
        return NULL;
    }
    /*
     * encode the float as an opaque 
     */
    /*
     * turn into Opaque holding special tagged value 
     */

    /*
     * put the tag and length for the Opaque wrapper 
     */
    data = asn_build_header(data, datalength, ASN_OPAQUE, floatsize + 3);
    if (_asn_build_header_check
        ("build float", data, *datalength, (floatsize + 3)))
        return NULL;

    /*
     * put the special tag and length 
     */
    *data++ = ASN_OPAQUE_TAG1;
    *data++ = ASN_OPAQUE_FLOAT;
    *data++ = (u_char) floatsize;
    *datalength = *datalength - 3;

    fu.floatVal = *floatp;
    /*
     * correct for endian differences 
     */
    fu.intVal = htonl(fu.intVal);

    *datalength -= floatsize;
    memcpy(data, &fu.c[0], floatsize);

    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGMSG(("dumpv_send", "Opaque float: %f\n", *floatp));
    data += floatsize;
    return data;
}


u_char         *
asn_parse_double(u_char * data,
                 size_t * datalength,
                 u_char * type, double *doublep, size_t doublesize)
{
    static const char *errpre = "parse double";
    register u_char *bufp = data;
    u_long          asn_length;
    long            tmp;
    union {
        double          doubleVal;
        int             intVal[2];
        u_char          c[sizeof(double)];
    } fu;


    if (doublesize != sizeof(double)) {
        _asn_size_err("parse double", doublesize, sizeof(double));
        return NULL;
    }
    *type = *bufp++;
    bufp = asn_parse_length(bufp, &asn_length);
    if (_asn_parse_length_check("parse double", bufp, data,
                                asn_length, *datalength))
        return NULL;

    DEBUGDUMPSETUP("recv", data, bufp - data + asn_length);
    /*
     * the double is encoded as an opaque 
     */
    if ((*type == ASN_OPAQUE) &&
        (asn_length == ASN_OPAQUE_DOUBLE_BER_LEN) &&
        (*bufp == ASN_OPAQUE_TAG1) && (*(bufp + 1) == ASN_OPAQUE_DOUBLE)) {

        /*
         * value is encoded as special format 
         */
        bufp = asn_parse_length(bufp + 2, &asn_length);
        if (_asn_parse_length_check("parse opaque double", bufp, data,
                                    asn_length, *datalength))
            return NULL;

        /*
         * change type to Double 
         */
        *type = ASN_OPAQUE_DOUBLE;
    }

    if (*type != ASN_OPAQUE_DOUBLE) {
        _asn_type_err(errpre, *type);
        return NULL;
    }

    if (asn_length != sizeof(double)) {
        _asn_size_err("parse seq double", asn_length, sizeof(double));
        return NULL;
    }
    *datalength -= (int) asn_length + (bufp - data);
    memcpy(&fu.c[0], bufp, asn_length);

    /*
     * correct for endian differences 
     */

    tmp = ntohl(fu.intVal[0]);
    fu.intVal[0] = ntohl(fu.intVal[1]);
    fu.intVal[1] = tmp;

    *doublep = fu.doubleVal;
    DEBUGMSG(("dumpv_recv", "  Opaque Double:\t%f\n", *doublep));

    return bufp;
}


u_char         *
asn_build_double(u_char * data,
                 size_t * datalength,
                 u_char type, const double *doublep, size_t doublesize)
{
    long            tmp;
    union {
        double          doubleVal;
        int             intVal[2];
        u_char          c[sizeof(double)];
    } fu;
#ifndef NETSNMP_NO_DEBUGGING
    u_char         *initdatap = data;
#endif

    if (doublesize != sizeof(double)) {
        _asn_size_err("build double", doublesize, sizeof(double));
        return NULL;
    }

    /*
     * encode the double as an opaque 
     */
    /*
     * turn into Opaque holding special tagged value 
     */

    /*
     * put the tag and length for the Opaque wrapper 
     */
    data = asn_build_header(data, datalength, ASN_OPAQUE, doublesize + 3);
    if (_asn_build_header_check
        ("build double", data, *datalength, doublesize + 3))
        return NULL;

    /*
     * put the special tag and length 
     */
    *data++ = ASN_OPAQUE_TAG1;
    *data++ = ASN_OPAQUE_DOUBLE;
    *data++ = (u_char) doublesize;
    *datalength = *datalength - 3;

    fu.doubleVal = *doublep;
    /*
     * correct for endian differences 
     */
    tmp = htonl(fu.intVal[0]);
    fu.intVal[0] = htonl(fu.intVal[1]);
    fu.intVal[1] = tmp;
    *datalength -= doublesize;
    memcpy(data, &fu.c[0], doublesize);

    data += doublesize;
    DEBUGDUMPSETUP("send", initdatap, data - initdatap);
    DEBUGMSG(("dumpv_send", "  Opaque double: %f\n", *doublep));
    return data;
}

#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */


int
asn_realloc(u_char ** pkt, size_t * pkt_len)
{
    if (pkt != NULL && pkt_len != NULL) {
        size_t          old_pkt_len = *pkt_len;

        DEBUGMSGTL(("asn_realloc", " old_pkt %8p, old_pkt_len %lu\n",
                    *pkt, (unsigned long)old_pkt_len));

        if (snmp_realloc(pkt, pkt_len)) {
            DEBUGMSGTL(("asn_realloc", " new_pkt %8p, new_pkt_len %lu\n",
                        *pkt, (unsigned long)*pkt_len));
            DEBUGMSGTL(("asn_realloc",
                        " memmove(%8p + %08x, %8p, %08x)\n",
                        *pkt, (unsigned)(*pkt_len - old_pkt_len),
                        *pkt, (unsigned)old_pkt_len));
            memmove(*pkt + (*pkt_len - old_pkt_len), *pkt, old_pkt_len);
            memset(*pkt, (int) ' ', *pkt_len - old_pkt_len);
            return 1;
        } else {
            DEBUGMSG(("asn_realloc", " CANNOT REALLOC()\n"));
        }
    }
    return 0;
}

#ifdef NETSNMP_USE_REVERSE_ASNENCODING

int
asn_realloc_rbuild_length(u_char ** pkt, size_t * pkt_len,
                          size_t * offset, int r, size_t length)
{
    static const char *errpre = "build length";
    char            ebuf[128];
    int             tmp_int;
    size_t          start_offset = *offset;

    if (length <= 0x7f) {
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            snprintf(ebuf, sizeof(ebuf),
                    "%s: bad length < 1 :%ld, %lu", errpre,
                    (long)(*pkt_len - *offset), (unsigned long)length);
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = length;
    } else {
        while (length > 0xff) {
            if (((*pkt_len - *offset) < 1)
                && !(r && asn_realloc(pkt, pkt_len))) {
                snprintf(ebuf, sizeof(ebuf),
                        "%s: bad length < 1 :%ld, %lu", errpre,
                        (long)(*pkt_len - *offset), (unsigned long)length);
                ebuf[ sizeof(ebuf)-1 ] = 0;
                ERROR_MSG(ebuf);
                return 0;
            }
            *(*pkt + *pkt_len - (++*offset)) = length & 0xff;
            length >>= 8;
        }

        while ((*pkt_len - *offset) < 2) {
            if (!(r && asn_realloc(pkt, pkt_len))) {
                snprintf(ebuf, sizeof(ebuf),
                        "%s: bad length < 1 :%ld, %lu", errpre,
                        (long)(*pkt_len - *offset), (unsigned long)length);
                ebuf[ sizeof(ebuf)-1 ] = 0;
                ERROR_MSG(ebuf);
                return 0;
            }
        }

        *(*pkt + *pkt_len - (++*offset)) = length & 0xff;
        tmp_int = *offset - start_offset;
        *(*pkt + *pkt_len - (++*offset)) = tmp_int | 0x80;
    }

    return 1;
}

int
asn_realloc_rbuild_header(u_char ** pkt, size_t * pkt_len,
                          size_t * offset, int r,
                          u_char type, size_t length)
{
    char            ebuf[128];

    if (asn_realloc_rbuild_length(pkt, pkt_len, offset, r, length)) {
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            snprintf(ebuf, sizeof(ebuf),
                    "bad header length < 1 :%ld, %lu",
                    (long)(*pkt_len - *offset), (unsigned long)length);
            ebuf[ sizeof(ebuf)-1 ] = 0;
            ERROR_MSG(ebuf);
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = type;
        return 1;
    }
    return 0;
}

int
asn_realloc_rbuild_int(u_char ** pkt, size_t * pkt_len,
                       size_t * offset, int r,
                       u_char type, const long *intp, size_t intsize)
{
    static const char *errpre = "build int";
    register long   integer = *intp;
    int             testvalue;
    size_t          start_offset = *offset;

    if (intsize != sizeof(long)) {
        _asn_size_err(errpre, intsize, sizeof(long));
        return 0;
    }

    CHECK_OVERFLOW_S(integer,10);
    testvalue = (integer < 0) ? -1 : 0;

    if (((*pkt_len - *offset) < 1) && !(r && asn_realloc(pkt, pkt_len))) {
        return 0;
    }
    *(*pkt + *pkt_len - (++*offset)) = (u_char) integer;
    integer >>= 8;

    while (integer != testvalue) {
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) integer;
        integer >>= 8;
    }

    if ((*(*pkt + *pkt_len - *offset) & 0x80) != (testvalue & 0x80)) {
        /*
         * Make sure left most bit is representational of the rest of the bits
         * that aren't encoded.  
         */
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = testvalue & 0xff;
    }

    if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r, type,
                                  (*offset - start_offset))) {
        if (_asn_realloc_build_header_check(errpre, pkt, pkt_len,
                                            (*offset - start_offset))) {
            return 0;
        } else {
            DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                           (*offset - start_offset));
            DEBUGMSG(("dumpv_send", "  Integer:\t%ld (0x%.2lX)\n", *intp,
                      *intp));
            return 1;
        }
    }

    return 0;
}

int
asn_realloc_rbuild_string(u_char ** pkt, size_t * pkt_len,
                          size_t * offset, int r,
                          u_char type,
                          const u_char * str, size_t strlength)
{
    static const char *errpre = "build string";
    size_t          start_offset = *offset;

    while ((*pkt_len - *offset) < strlength) {
        if (!(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
    }

    *offset += strlength;
    memcpy(*pkt + *pkt_len - *offset, str, strlength);

    if (asn_realloc_rbuild_header
        (pkt, pkt_len, offset, r, type, strlength)) {
        if (_asn_realloc_build_header_check
            (errpre, pkt, pkt_len, strlength)) {
            return 0;
        } else {
            DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                           *offset - start_offset);
            DEBUGIF("dumpv_send") {
                if (strlength == 0) {
                    DEBUGMSG(("dumpv_send", "  String: [NULL]\n"));
                } else {
                    u_char         *buf = (u_char *) malloc(2 * strlength);
                    size_t          l =
                        (buf != NULL) ? (2 * strlength) : 0, ol = 0;

                    if (sprint_realloc_asciistring
                        (&buf, &l, &ol, 1, str, strlength)) {
                        DEBUGMSG(("dumpv_send", "  String:\t%s\n", buf));
                    } else {
                        if (buf == NULL) {
                            DEBUGMSG(("dumpv_send",
                                      "  String:\t[TRUNCATED]\n"));
                        } else {
                            DEBUGMSG(("dumpv_send",
                                      "  String:\t%s [TRUNCATED]\n", buf));
                        }
                    }
                    if (buf != NULL) {
                        free(buf);
                    }
                }
            }
        }
        return 1;
    }

    return 0;
}

int
asn_realloc_rbuild_unsigned_int(u_char ** pkt, size_t * pkt_len,
                                size_t * offset, int r,
                            u_char type, const u_long * intp, size_t intsize)
{
    static const char *errpre = "build uint";
    register u_long integer = *intp;
    size_t          start_offset = *offset;

    if (intsize != sizeof(unsigned long)) {
        _asn_size_err(errpre, intsize, sizeof(unsigned long));
        return 0;
    }

    CHECK_OVERFLOW_U(integer,11);

    if (((*pkt_len - *offset) < 1) && !(r && asn_realloc(pkt, pkt_len))) {
        return 0;
    }
    *(*pkt + *pkt_len - (++*offset)) = (u_char) integer;
    integer >>= 8;

    while (integer != 0) {
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) integer;
        integer >>= 8;
    }

    if ((*(*pkt + *pkt_len - *offset) & 0x80) != (0 & 0x80)) {
        /*
         * Make sure left most bit is representational of the rest of the bits
         * that aren't encoded.  
         */
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = 0;
    }

    if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r, type,
                                  (*offset - start_offset))) {
        if (_asn_realloc_build_header_check(errpre, pkt, pkt_len,
                                            (*offset - start_offset))) {
            return 0;
        } else {
            DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                           (*offset - start_offset));
            DEBUGMSG(("dumpv_send", "  UInteger:\t%lu (0x%.2lX)\n", *intp,
                      *intp));
            return 1;
        }
    }

    return 0;
}

int
asn_realloc_rbuild_sequence(u_char ** pkt, size_t * pkt_len,
                            size_t * offset, int r,
                            u_char type, size_t length)
{
    return asn_realloc_rbuild_header(pkt, pkt_len, offset, r, type,
                                     length);
}

int
asn_realloc_rbuild_objid(u_char ** pkt, size_t * pkt_len,
                         size_t * offset, int r,
                         u_char type,
                         const oid * objid, size_t objidlength)
{
    /*
     * ASN.1 objid ::= 0x06 asnlength subidentifier {subidentifier}*
     * subidentifier ::= {leadingbyte}* lastbyte
     * leadingbyte ::= 1 7bitvalue
     * lastbyte ::= 0 7bitvalue
     */
    register size_t i;
    register oid    tmpint;
    size_t          start_offset = *offset;
    const char     *errpre = "build objid";

    /*
     * Check if there are at least 2 sub-identifiers.  
     */
    if (objidlength == 0) {
        /*
         * There are not, so make OID have two with value of zero.  
         */
        while ((*pkt_len - *offset) < 2) {
            if (!(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
        }

        *(*pkt + *pkt_len - (++*offset)) = 0;
        *(*pkt + *pkt_len - (++*offset)) = 0;
    } else if (objid[0] > 2) {
        ERROR_MSG("build objid: bad first subidentifier");
        return 0;
    } else if (objidlength == 1) {
        /*
         * Encode the first value.  
         */
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) objid[0];
    } else {
        for (i = objidlength; i > 2; i--) {
            tmpint = objid[i - 1];
            CHECK_OVERFLOW_U(tmpint,12);

            if (((*pkt_len - *offset) < 1)
                && !(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
            *(*pkt + *pkt_len - (++*offset)) = (u_char) tmpint & 0x7f;
            tmpint >>= 7;

            while (tmpint > 0) {
                if (((*pkt_len - *offset) < 1)
                    && !(r && asn_realloc(pkt, pkt_len))) {
                    return 0;
                }
                *(*pkt + *pkt_len - (++*offset)) =
                    (u_char) ((tmpint & 0x7f) | 0x80);
                tmpint >>= 7;
            }
        }

        /*
         * Combine the first two values.  
         */
        if ((objid[1] > 40) &&
            (objid[0] < 2)) {
            ERROR_MSG("build objid: bad second subidentifier");
            return 0;
        }
        tmpint = ((objid[0] * 40) + objid[1]);
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) tmpint & 0x7f;
        tmpint >>= 7;

        while (tmpint > 0) {
            if (((*pkt_len - *offset) < 1)
                && !(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
            *(*pkt + *pkt_len - (++*offset)) =
                (u_char) ((tmpint & 0x7f) | 0x80);
            tmpint >>= 7;
        }
    }

    tmpint = *offset - start_offset;
    if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r, type,
                                  (*offset - start_offset))) {
        if (_asn_realloc_build_header_check(errpre, pkt, pkt_len,
                                            (*offset - start_offset))) {
            return 0;
        } else {
            DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                           (*offset - start_offset));
            DEBUGMSG(("dumpv_send", "  ObjID: "));
            DEBUGMSGOID(("dumpv_send", objid, objidlength));
            DEBUGMSG(("dumpv_send", "\n"));
            return 1;
        }
    }

    return 0;
}

int
asn_realloc_rbuild_null(u_char ** pkt, size_t * pkt_len,
                        size_t * offset, int r, u_char type)
{
    /*
     * ASN.1 null ::= 0x05 0x00
     */
    size_t          start_offset = *offset;

    if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r, type, 0)) {
        DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                       (*offset - start_offset));
        DEBUGMSG(("dumpv_send", "  NULL\n"));
        return 1;
    } else {
        return 0;
    }
}

int
asn_realloc_rbuild_bitstring(u_char ** pkt, size_t * pkt_len,
                             size_t * offset, int r,
                             u_char type,
                             const u_char * str, size_t strlength)
{
    /*
     * ASN.1 bit string ::= 0x03 asnlength unused {byte}*
     */
    static const char *errpre = "build bitstring";
    size_t          start_offset = *offset;

    while ((*pkt_len - *offset) < strlength) {
        if (!(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
    }

    *offset += strlength;
    memcpy(*pkt + *pkt_len - *offset, str, strlength);

    if (asn_realloc_rbuild_header
        (pkt, pkt_len, offset, r, type, strlength)) {
        if (_asn_realloc_build_header_check
            (errpre, pkt, pkt_len, strlength)) {
            return 0;
        } else {
            DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                           *offset - start_offset);
            DEBUGIF("dumpv_send") {
                if (strlength == 0) {
                    DEBUGMSG(("dumpv_send", "  Bitstring: [NULL]\n"));
                } else {
                    u_char         *buf = (u_char *) malloc(2 * strlength);
                    size_t          l =
                        (buf != NULL) ? (2 * strlength) : 0, ol = 0;

                    if (sprint_realloc_asciistring
                        (&buf, &l, &ol, 1, str, strlength)) {
                        DEBUGMSG(("dumpv_send", "  Bitstring:\t%s\n",
                                  buf));
                    } else {
                        if (buf == NULL) {
                            DEBUGMSG(("dumpv_send",
                                      "  Bitstring:\t[TRUNCATED]\n"));
                        } else {
                            DEBUGMSG(("dumpv_send",
                                      "  Bitstring:\t%s [TRUNCATED]\n",
                                      buf));
                        }
                    }
                    if (buf != NULL) {
                        free(buf);
                    }
                }
            }
        }
        return 1;
    }

    return 0;
}

int
asn_realloc_rbuild_unsigned_int64(u_char ** pkt, size_t * pkt_len,
                                  size_t * offset, int r,
                                  u_char type,
                               const struct counter64 *cp, size_t countersize)
{
    /*
     * ASN.1 integer ::= 0x02 asnlength byte {byte}*
     */
    register u_long low = cp->low, high = cp->high;
    size_t          intsize, start_offset = *offset;
    int             count;

    if (countersize != sizeof(struct counter64)) {
        _asn_size_err("build uint64", countersize,
                      sizeof(struct counter64));
        return 0;
    }

    CHECK_OVERFLOW_U(high,13);
    CHECK_OVERFLOW_U(low,13);

    /*
     * Encode the low 4 bytes first.  
     */
    if (((*pkt_len - *offset) < 1) && !(r && asn_realloc(pkt, pkt_len))) {
        return 0;
    }
    *(*pkt + *pkt_len - (++*offset)) = (u_char) low;
    low >>= 8;
    count = 1;

    while (low != 0) {
        count++;
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) low;
        low >>= 8;
    }

    /*
     * Then the high byte if present.  
     */
    if (high) {
        /*
         * Do the rest of the low byte.  
         */
        for (; count < 4; count++) {
            if (((*pkt_len - *offset) < 1)
                && !(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
            *(*pkt + *pkt_len - (++*offset)) = 0;
        }

        /*
         * Do high byte.  
         */
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) high;
        high >>= 8;

        while (high != 0) {
            if (((*pkt_len - *offset) < 1)
                && !(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
            *(*pkt + *pkt_len - (++*offset)) = (u_char) high;
            high >>= 8;
        }
    }

    if ((*(*pkt + *pkt_len - *offset) & 0x80) != (0 & 0x80)) {
        /*
         * Make sure left most bit is representational of the rest of the bits
         * that aren't encoded.  
         */
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = 0;
    }

    intsize = *offset - start_offset;

#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
    /*
     * Encode a Counter64 as an opaque (it also works in SNMPv1).  
     */
    if (type == ASN_OPAQUE_COUNTER64) {
        while ((*pkt_len - *offset) < 5) {
            if (!(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
        }

        *(*pkt + *pkt_len - (++*offset)) = (u_char) intsize;
        *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_COUNTER64;
        *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_TAG1;

        /*
         * Put the tag and length for the Opaque wrapper.  
         */
        if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r,
                                      ASN_OPAQUE, intsize + 3)) {
            if (_asn_realloc_build_header_check
                ("build counter u64", pkt, pkt_len, intsize + 3)) {
                return 0;
            }
        } else {
            return 0;
        }
    } else if (type == ASN_OPAQUE_U64) {
        /*
         * Encode the Unsigned int64 in an opaque.  
         */
        while ((*pkt_len - *offset) < 5) {
            if (!(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
        }

        *(*pkt + *pkt_len - (++*offset)) = (u_char) intsize;
        *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_U64;
        *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_TAG1;

        /*
         * Put the tag and length for the Opaque wrapper.  
         */
        if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r,
                                      ASN_OPAQUE, intsize + 3)) {
            if (_asn_realloc_build_header_check
                ("build counter u64", pkt, pkt_len, intsize + 3)) {
                return 0;
            }
        } else {
            return 0;
        }
    } else {

#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */
        if (asn_realloc_rbuild_header
            (pkt, pkt_len, offset, r, type, intsize)) {
            if (_asn_realloc_build_header_check
                ("build uint64", pkt, pkt_len, intsize)) {
                return 0;
            }
        } else {
            return 0;
        }
#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES
    }
#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */

    DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset), intsize);
    DEBUGMSG(("dumpv_send", "  U64:\t%lu %lu\n", cp->high, cp->low));
    return 1;
}

#ifdef NETSNMP_WITH_OPAQUE_SPECIAL_TYPES


int
asn_realloc_rbuild_signed_int64(u_char ** pkt, size_t * pkt_len,
                                size_t * offset, int r,
                                u_char type,
                                const struct counter64 *cp, size_t countersize)
{
    /*
     * ASN.1 integer ::= 0x02 asnlength byte {byte}*
     */
    register long low = cp->low, high = cp->high;
    size_t          intsize, start_offset = *offset;
    int             count, testvalue = (high & 0x80000000) ? -1 : 0;

    if (countersize != sizeof(struct counter64)) {
        _asn_size_err("build uint64", countersize,
                      sizeof(struct counter64));
        return 0;
    }

    CHECK_OVERFLOW_S(high,14);
    CHECK_OVERFLOW_U(low,14);

    /*
     * Encode the low 4 bytes first.  
     */
    if (((*pkt_len - *offset) < 1) && !(r && asn_realloc(pkt, pkt_len))) {
        return 0;
    }
    *(*pkt + *pkt_len - (++*offset)) = (u_char) low;
    low >>= 8;
    count = 1;

    while ((int) low != testvalue && count < 4) {
        count++;
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) low;
        low >>= 8;
    }

    /*
     * Then the high byte if present.  
     */
    if (high != testvalue) {
        /*
         * Do the rest of the low byte.  
         */
        for (; count < 4; count++) {
            if (((*pkt_len - *offset) < 1)
                && !(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
            *(*pkt + *pkt_len - (++*offset)) = (testvalue == 0) ? 0 : 0xff;
        }

        /*
         * Do high byte.  
         */
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (u_char) high;
        high >>= 8;

        while ((int) high != testvalue) {
            if (((*pkt_len - *offset) < 1)
                && !(r && asn_realloc(pkt, pkt_len))) {
                return 0;
            }
            *(*pkt + *pkt_len - (++*offset)) = (u_char) high;
            high >>= 8;
        }
    }

    if ((*(*pkt + *pkt_len - *offset) & 0x80) != (testvalue & 0x80)) {
        /*
         * Make sure left most bit is representational of the rest of the bits
         * that aren't encoded.  
         */
        if (((*pkt_len - *offset) < 1)
            && !(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
        *(*pkt + *pkt_len - (++*offset)) = (testvalue == 0) ? 0 : 0xff;
    }

    intsize = *offset - start_offset;

    while ((*pkt_len - *offset) < 5) {
        if (!(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
    }

    *(*pkt + *pkt_len - (++*offset)) = (u_char) intsize;
    *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_I64;
    *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_TAG1;

    /*
     * Put the tag and length for the Opaque wrapper.  
     */
    if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r,
                                  ASN_OPAQUE, intsize + 3)) {
        if (_asn_realloc_build_header_check
            ("build counter u64", pkt, pkt_len, intsize + 3)) {
            return 0;
        }
    } else {
        return 0;
    }

    DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset), intsize);
    DEBUGMSG(("dumpv_send", "  UInt64:\t%lu %lu\n", cp->high, cp->low));
    return 1;
}

int
asn_realloc_rbuild_float(u_char ** pkt, size_t * pkt_len,
                         size_t * offset, int r,
                         u_char type, const float *floatp, size_t floatsize)
{
    size_t          start_offset = *offset;
    union {
        float           floatVal;
        int             intVal;
        u_char          c[sizeof(float)];
    } fu;

    /*
     * Floatsize better not be larger than realistic.  
     */
    if (floatsize != sizeof(float) || floatsize > 122) {
        return 0;
    }

    while ((*pkt_len - *offset) < floatsize + 3) {
        if (!(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
    }

    /*
     * Correct for endian differences and copy value.  
     */
    fu.floatVal = *floatp;
    fu.intVal = htonl(fu.intVal);
    *offset += floatsize;
    memcpy(*pkt + *pkt_len - *offset, &(fu.c[0]), floatsize);

    /*
     * Put the special tag and length (3 bytes).  
     */
    *(*pkt + *pkt_len - (++*offset)) = (u_char) floatsize;
    *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_FLOAT;
    *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_TAG1;

    /*
     * Put the tag and length for the Opaque wrapper.  
     */
    if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r,
                                  ASN_OPAQUE, floatsize + 3)) {
        if (_asn_realloc_build_header_check("build float", pkt, pkt_len,
                                            floatsize + 3)) {
            return 0;
        } else {
            DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                           *offset - start_offset);
            DEBUGMSG(("dumpv_send", "Opaque Float:\t%f\n", *floatp));
            return 1;
        }
    }

    return 0;
}

int
asn_realloc_rbuild_double(u_char ** pkt, size_t * pkt_len,
                          size_t * offset, int r,
                          u_char type, const double *doublep, size_t doublesize)
{
    size_t          start_offset = *offset;
    long            tmp;
    union {
        double          doubleVal;
        int             intVal[2];
        u_char          c[sizeof(double)];
    } fu;

    /*
     * Doublesize better not be larger than realistic.  
     */
    if (doublesize != sizeof(double) || doublesize > 122) {
        return 0;
    }

    while ((*pkt_len - *offset) < doublesize + 3) {
        if (!(r && asn_realloc(pkt, pkt_len))) {
            return 0;
        }
    }

    /*
     * Correct for endian differences and copy value.  
     */
    fu.doubleVal = *doublep;
    tmp = htonl(fu.intVal[0]);
    fu.intVal[0] = htonl(fu.intVal[1]);
    fu.intVal[1] = tmp;
    *offset += doublesize;
    memcpy(*pkt + *pkt_len - *offset, &(fu.c[0]), doublesize);

    /*
     * Put the special tag and length (3 bytes).  
     */
    *(*pkt + *pkt_len - (++*offset)) = (u_char) doublesize;
    *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_DOUBLE;
    *(*pkt + *pkt_len - (++*offset)) = ASN_OPAQUE_TAG1;

    /*
     * Put the tag and length for the Opaque wrapper.  
     */
    if (asn_realloc_rbuild_header(pkt, pkt_len, offset, r,
                                  ASN_OPAQUE, doublesize + 3)) {
        if (_asn_realloc_build_header_check("build float", pkt, pkt_len,
                                            doublesize + 3)) {
            return 0;
        } else {
            DEBUGDUMPSETUP("send", (*pkt + *pkt_len - *offset),
                           *offset - start_offset);
            DEBUGMSG(("dumpv_send", "  Opaque Double:\t%f\n", *doublep));
            return 1;
        }
    }

    return 0;
}

#endif                          /* NETSNMP_WITH_OPAQUE_SPECIAL_TYPES */
#endif                          /*  NETSNMP_USE_REVERSE_ASNENCODING  */