ldap/ber/encode.c

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

/*
 * Copyright (c) 1990 Regents of the University of Michigan.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that this notice is preserved and that due credit is given
 * to the University of Michigan at Ann Arbor. The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific prior written permission. This software
 * is provided ``as is'' without express or implied warranty.
 */

/* encode.c - ber output encoding routines */

#include "lber-int.h"

/* the following constants are used in ber_calc_lenlen */

#define LENMASK1    0xFF
#define LENMASK2    0xFFFF
#define LENMASK3    0xFFFFFF
#define LENMASK4    0xFFFFFFFF
#define _MASK       0x80

static int
ber_calc_taglen( ber_tag_t tag )
{
    int     i;
    ber_int_t   mask;

    /* find the first non-all-zero byte in the tag */
    for ( i = sizeof(ber_int_t) - 1; i > 0; i-- ) {
        mask = (LENMASK3 << (i * 8));
        /* not all zero */
        if ( tag & mask )
            break;
    }

    return( i + 1 );
}

static int
ber_put_tag( BerElement *ber, ber_tag_t tag, int nosos )
{
    int     taglen;
    ber_tag_t   ntag;

    taglen = ber_calc_taglen( tag );

    ntag = LBER_HTONL( tag );

    return( ber_write( ber, ((char *) &ntag) + sizeof(ber_int_t) - taglen,
        taglen, nosos ) );
}

static int
ber_calc_lenlen( ber_len_t len )
{
    /*
     * short len if it's less than 128 - one byte giving the len,
     * with bit 8 0.
     */

    if ( len <= 0x7F )
        return( 1 );

    /*
     * long len otherwise - one byte with bit 8 set, giving the
     * length of the length, followed by the length itself.
     */

    if ( len <= LENMASK1 )
        return( 2 );
    if ( len <= LENMASK2 )
        return( 3 );
    if ( len <= LENMASK3 )
        return( 4 );

    return( 5 );
}

static int
ber_put_len( BerElement *ber, ber_len_t len, int nosos )
{
    int     i;
    char        lenlen;
    ber_int_t   mask;
    ber_len_t   netlen;

    /*
     * short len if it's less than 128 - one byte giving the len,
     * with bit 8 0.
     */

    if ( len <= 127 ) {
        netlen = LBER_HTONL( len );
        return( ber_write( ber, (char *) &netlen + sizeof(ber_int_t) - 1,
            1, nosos ) );
    }

    /*
     * long len otherwise - one byte with bit 8 set, giving the
     * length of the length, followed by the length itself.
     */

    /* find the first non-all-zero byte */
    for ( i = sizeof(ber_int_t) - 1; i > 0; i-- ) {
        mask = (LENMASK1 << (i * 8));
        /* not all zero */
        if ( len & mask )
            break;
    }
    lenlen = ++i;
    if ( lenlen > 4 )
        return( -1 );
    lenlen |= 0x80;

    /* write the length of the length */
    if ( ber_write( ber, &lenlen, 1, nosos ) != 1 )
        return( -1 );

    /* write the length itself */
    netlen = LBER_HTONL( len );
    if ( ber_write( ber, (char *) &netlen + (sizeof(ber_int_t) - i), i, nosos )
        != i )
        return( -1 );

    return( i + 1 );
}

static int
ber_put_int_or_enum( BerElement *ber, ber_int_t num, ber_tag_t tag )
{
    int     i, sign, taglen;
    int     len, lenlen;
    ber_int_t   netnum, mask;

    sign = (num < 0);

    /*
     * high bit is set - look for first non-all-one byte
     * high bit is clear - look for first non-all-zero byte
     */
    for ( i = sizeof(ber_int_t) - 1; i > 0; i-- ) {
        mask = (LENMASK1 << (i * 8));

        if ( sign ) {
            /* not all ones */
            if ( (num & mask) != mask )
                break;
        } else {
            /* not all zero */
            if ( num & mask )
                break;
        }
    }

    /*
     * we now have the "leading byte".  if the high bit on this
     * byte matches the sign bit, we need to "back up" a byte.
     */
    mask = (num & (_MASK << (i * 8)));
    if ( (mask && !sign) || (sign && !mask) )
        i++;

    len = i + 1;

    if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
        return( -1 );

    if ( (lenlen = ber_put_len( ber, len, 0 )) == -1 )
        return( -1 );
    i++;
    netnum = LBER_HTONL( num );
    if ( ber_write( ber, (char *) &netnum + (sizeof(ber_int_t) - i), i, 0 )
        == i)
        /* length of tag + length + contents */
        return( taglen + lenlen + i );

    return( -1 );
}

int
LDAP_CALL
ber_put_enum( BerElement *ber, ber_int_t num, ber_tag_t tag )
{
    if ( tag == LBER_DEFAULT )
        tag = LBER_ENUMERATED;

    return( ber_put_int_or_enum( ber, num, tag ) );
}

int
LDAP_CALL
ber_put_int( BerElement *ber, ber_int_t num, ber_tag_t tag )
{
    if ( tag == LBER_DEFAULT )
        tag = LBER_INTEGER;

    return( ber_put_int_or_enum( ber, num, tag ) );
}

int
LDAP_CALL
ber_put_ostring( BerElement *ber, char *str, ber_len_t len,
    ber_tag_t tag )
{
    int taglen, lenlen, rc;
#ifdef STR_TRANSLATION
    int free_str;
#endif /* STR_TRANSLATION */

    if ( tag == LBER_DEFAULT )
        tag = LBER_OCTETSTRING;

    if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
        return( -1 );

#ifdef STR_TRANSLATION
    if ( len > 0 && ( ber->ber_options & LBER_OPT_TRANSLATE_STRINGS ) != 0
        && ber->ber_encode_translate_proc != NULL ) {
        if ( (*(ber->ber_encode_translate_proc))( &str, &len, 0 )
            != 0 ) {
            return( -1 );
        }
        free_str = 1;
    } else {
        free_str = 0;
    }
#endif /* STR_TRANSLATION */

    /*
     *  Note:  below is a spot where we limit ber_write
     *         to signed long (instead of unsigned long)
     */

    if ( (lenlen = ber_put_len( ber, len, 0 )) == -1 ||
        ber_write( ber, str, len, 0 ) != (ber_int_t) len ) {
        rc = -1;
    } else {
        /* return length of tag + length + contents */
        rc = taglen + lenlen + len;
    }

#ifdef STR_TRANSLATION
    if ( free_str ) {
        NSLBERI_FREE( str );
    }
#endif /* STR_TRANSLATION */

    return( rc );
}

int
LDAP_CALL
ber_put_string( BerElement *ber, char *str, ber_tag_t tag )
{
    return( ber_put_ostring( ber, str, (ber_len_t) strlen( str ), tag ));
}

int
LDAP_CALL
ber_put_bitstring( BerElement *ber, char *str,
    ber_len_t blen /* in bits */, ber_tag_t tag )
{
    int     taglen, lenlen, len;
    unsigned char   unusedbits;

    if ( tag == LBER_DEFAULT )
        tag = LBER_BITSTRING;

    if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
        return( -1 );

    len = ( blen + 7 ) / 8;
    unusedbits = (unsigned char) (len * 8 - blen);
    if ( (lenlen = ber_put_len( ber, len + 1, 0 )) == -1 )
        return( -1 );

    if ( ber_write( ber, (char *)&unusedbits, 1, 0 ) != 1 )
        return( -1 );

    if ( ber_write( ber, str, len, 0 ) != len )
        return( -1 );

    /* return length of tag + length + unused bit count + contents */
    return( taglen + 1 + lenlen + len );
}

int
LDAP_CALL
ber_put_null( BerElement *ber, ber_tag_t tag )
{
    int taglen;

    if ( tag == LBER_DEFAULT )
        tag = LBER_NULL;

    if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
        return( -1 );

    if ( ber_put_len( ber, 0, 0 ) != 1 )
        return( -1 );

    return( taglen + 1 );
}

int
LDAP_CALL
ber_put_boolean( BerElement *ber, int boolval, ber_tag_t tag )
{
    int     taglen;
    unsigned char   trueval = 0xff;
    unsigned char   falseval = 0x00;

    if ( tag == LBER_DEFAULT )
        tag = LBER_BOOLEAN;

    if ( (taglen = ber_put_tag( ber, tag, 0 )) == -1 )
        return( -1 );

    if ( ber_put_len( ber, 1, 0 ) != 1 )
        return( -1 );

    if ( ber_write( ber, (char *)(boolval ? &trueval : &falseval), 1, 0 )
        != 1 )
        return( -1 );

    return( taglen + 2 );
}

#define FOUR_BYTE_LEN   5


/* the idea here is roughly this: we maintain a stack of these Seqorset
 * structures. This is pushed when we see the beginning of a new set or
 * sequence. It is popped when we see the end of a set or sequence.
 * Since we don't want to malloc and free these structures all the time,
 * we pre-allocate a small set of them within the ber element structure.
 * thus we need to spot when we've overflowed this stack and fall back to
 * malloc'ing instead.
 */
static int
ber_start_seqorset( BerElement *ber, ber_tag_t tag )
{
    Seqorset    *new_sos;

    /* can we fit into the local stack ? */
    if (ber->ber_sos_stack_posn < SOS_STACK_SIZE) {
        /* yes */
        new_sos = &ber->ber_sos_stack[ber->ber_sos_stack_posn];
    } else {
        /* no */
        if ( (new_sos = (Seqorset *)NSLBERI_MALLOC( sizeof(Seqorset)))
            == NULLSEQORSET ) {
            return( -1 );
        }
    }
    ber->ber_sos_stack_posn++;

    if ( ber->ber_sos == NULLSEQORSET )
        new_sos->sos_first = ber->ber_ptr;
    else
        new_sos->sos_first = ber->ber_sos->sos_ptr;

    /* Set aside room for a 4 byte length field */
    new_sos->sos_ptr = new_sos->sos_first + ber_calc_taglen( tag ) + FOUR_BYTE_LEN;
    new_sos->sos_tag = tag;

    new_sos->sos_next = ber->ber_sos;
    new_sos->sos_clen = 0;

    ber->ber_sos = new_sos;
    if (ber->ber_sos->sos_ptr > ber->ber_end) {
        nslberi_ber_realloc(ber, ber->ber_sos->sos_ptr - ber->ber_end);
    }
    return( 0 );
}

int
LDAP_CALL
ber_start_seq( BerElement *ber, ber_tag_t tag )
{
    if ( tag == LBER_DEFAULT )
        tag = LBER_SEQUENCE;

    return( ber_start_seqorset( ber, tag ) );
}

int
LDAP_CALL
ber_start_set( BerElement *ber, ber_tag_t tag )
{
    if ( tag == LBER_DEFAULT )
        tag = LBER_SET;

    return( ber_start_seqorset( ber, tag ) );
}

static int
ber_put_seqorset( BerElement *ber )
{
    ber_len_t   len, netlen;
    int     taglen, lenlen;
    unsigned char   ltag = 0x80 + FOUR_BYTE_LEN - 1;
    Seqorset    *next;
    Seqorset    **sos = &ber->ber_sos;

    /*
     * If this is the toplevel sequence or set, we need to actually
     * write the stuff out.  Otherwise, it's already been put in
     * the appropriate buffer and will be written when the toplevel
     * one is written.  In this case all we need to do is update the
     * length and tag.
     */

    len = (*sos)->sos_clen;
    netlen = LBER_HTONL( len );
    if ( sizeof(ber_int_t) > 4 && len > LENMASK4 )
        return( -1 );

    if ( ber->ber_options & LBER_OPT_USE_DER ) {
        lenlen = ber_calc_lenlen( len );
    } else {
        lenlen = FOUR_BYTE_LEN;
    }

    if ( (next = (*sos)->sos_next) == NULLSEQORSET ) {
        /* write the tag */
        if ( (taglen = ber_put_tag( ber, (*sos)->sos_tag, 1 )) == -1 )
            return( -1 );

        if ( ber->ber_options & LBER_OPT_USE_DER ) {
            /* Write the length in the minimum # of octets */
            if ( ber_put_len( ber, len, 1 ) == -1 )
                return( -1 );

            if (lenlen != FOUR_BYTE_LEN) {
                /*
                 * We set aside FOUR_BYTE_LEN bytes for
                 * the length field.  Move the data if
                 * we don't actually need that much
                 */
                SAFEMEMCPY( (*sos)->sos_first + taglen +
                    lenlen, (*sos)->sos_first + taglen +
                    FOUR_BYTE_LEN, len );
            }
        } else {
            /* Fill FOUR_BYTE_LEN bytes for length field */
            /* one byte of length length */
            if ( ber_write( ber, (char *)&ltag, 1, 1 ) != 1 )
                return( -1 );

            /* the length itself */
            if ( ber_write( ber, (char *) &netlen + sizeof(ber_int_t)
                - (FOUR_BYTE_LEN - 1), FOUR_BYTE_LEN - 1, 1 )
                != FOUR_BYTE_LEN - 1 )
                return( -1 );
        }
        /* The ber_ptr is at the set/seq start - move it to the end */
        ber->ber_ptr += len;
    } else {
        ber_tag_t   ntag;

        /* the tag */
        taglen = ber_calc_taglen( (*sos)->sos_tag );
        ntag = LBER_HTONL( (*sos)->sos_tag );
        SAFEMEMCPY( (*sos)->sos_first, (char *) &ntag +
            sizeof(ber_int_t) - taglen, taglen );

        if ( ber->ber_options & LBER_OPT_USE_DER ) {
            ltag = (lenlen == 1) ? (unsigned char)len :
                (unsigned char) (0x80 + (lenlen - 1));
        }

        /* one byte of length length */
        SAFEMEMCPY( (*sos)->sos_first + 1, &ltag, 1 );

        if ( ber->ber_options & LBER_OPT_USE_DER ) {
            if (lenlen > 1) {
                /* Write the length itself */
                SAFEMEMCPY( (*sos)->sos_first + 2,
                    (char *)&netlen + sizeof(ber_uint_t) -
                    (lenlen - 1),
                    lenlen - 1 );
            }
            if (lenlen != FOUR_BYTE_LEN) {
                /*
                 * We set aside FOUR_BYTE_LEN bytes for
                 * the length field.  Move the data if
                 * we don't actually need that much
                 */
                SAFEMEMCPY( (*sos)->sos_first + taglen +
                    lenlen, (*sos)->sos_first + taglen +
                    FOUR_BYTE_LEN, len );
            }
        } else {
            /* the length itself */
            SAFEMEMCPY( (*sos)->sos_first + taglen + 1,
                (char *) &netlen + sizeof(ber_int_t) -
                (FOUR_BYTE_LEN - 1), FOUR_BYTE_LEN - 1 );
        }

        next->sos_clen += (taglen + lenlen + len);
        next->sos_ptr += (taglen + lenlen + len);
    }

    /* we're done with this seqorset, so free it up */
    /* was this one from the local stack ? */
    if (ber->ber_sos_stack_posn <= SOS_STACK_SIZE) {
        /* yes */
    } else {
        /* no */
        NSLBERI_FREE( (char *) (*sos) );
    }
    ber->ber_sos_stack_posn--;
    *sos = next;

    return( taglen + lenlen + len );
}

int
LDAP_CALL
ber_put_seq( BerElement *ber )
{
    return( ber_put_seqorset( ber ) );
}

int
LDAP_CALL
ber_put_set( BerElement *ber )
{
    return( ber_put_seqorset( ber ) );
}

/* VARARGS */
int
LDAP_C
ber_printf( BerElement *ber, const char *fmt, ... )
{
    va_list     ap;
    char        *s, **ss;
    struct berval   *bval, **bv;
    int     rc, i;
    ber_len_t   len;

    va_start( ap, fmt );

#ifdef LDAP_DEBUG
    if ( lber_debug & 64 ) {
        char msg[80];
        sprintf( msg, "ber_printf fmt (%s)\n", fmt );
        ber_err_print( msg );
    }
#endif

    for ( rc = 0; *fmt && rc != -1; fmt++ ) {
        switch ( *fmt ) {
        case 'b':   /* boolean */
            i = va_arg( ap, int );
            rc = ber_put_boolean( ber, i, ber->ber_tag );
            break;

        case 'i':   /* int */
            i = va_arg( ap, int );
            rc = ber_put_int( ber, (ber_int_t)i, ber->ber_tag );
            break;

        case 'e':   /* enumeration */
            i = va_arg( ap, int );
            rc = ber_put_enum( ber, (ber_int_t)i, ber->ber_tag );
            break;

        case 'n':   /* null */
            rc = ber_put_null( ber, ber->ber_tag );
            break;

        case 'o':   /* octet string (non-null terminated) */
            s = va_arg( ap, char * );
            len = va_arg( ap, int );
            rc = ber_put_ostring( ber, s, len, ber->ber_tag );
            break;

        case 'O':   /* berval octet string */
            if( ( bval = va_arg( ap, struct berval * ) ) == NULL )
                break;
            if( bval->bv_len == 0 ) {
                rc = ber_put_ostring( ber, "", 0, ber->ber_tag );
            } else {
                rc = ber_put_ostring( ber, bval->bv_val, bval->bv_len,
                    ber->ber_tag );
            }
            break;

        case 's':   /* string */
            s = va_arg( ap, char * );
            rc = ber_put_string( ber, s, ber->ber_tag );
            break;

        case 'B':   /* bit string */
            s = va_arg( ap, char * );
            len = va_arg( ap, int );    /* in bits */
            rc = ber_put_bitstring( ber, s, len, ber->ber_tag );
            break;

        case 't':   /* tag for the next element */
            ber->ber_tag = va_arg( ap, ber_tag_t );
            ber->ber_usertag = 1;
            break;

        case 'v':   /* vector of strings */
            if ( (ss = va_arg( ap, char ** )) == NULL )
                break;
            for ( i = 0; ss[i] != NULL; i++ ) {
                if ( (rc = ber_put_string( ber, ss[i],
                    ber->ber_tag )) == -1 )
                    break;
            }
            break;

        case 'V':   /* sequences of strings + lengths */
            if ( (bv = va_arg( ap, struct berval ** )) == NULL )
                break;
            for ( i = 0; bv[i] != NULL; i++ ) {
                if ( (rc = ber_put_ostring( ber, bv[i]->bv_val,
                    bv[i]->bv_len, ber->ber_tag )) == -1 )
                    break;
            }
            break;

        case '{':   /* begin sequence */
            rc = ber_start_seq( ber, ber->ber_tag );
            break;

        case '}':   /* end sequence */
            rc = ber_put_seqorset( ber );
            break;

        case '[':   /* begin set */
            rc = ber_start_set( ber, ber->ber_tag );
            break;

        case ']':   /* end set */
            rc = ber_put_seqorset( ber );
            break;

        default: {
                char msg[80];
                sprintf( msg, "unknown fmt %c\n", *fmt );
                ber_err_print( msg );
                rc = -1;
                break;
            }
        }

        if ( ber->ber_usertag == 0 )
            ber->ber_tag = LBER_DEFAULT;
        else
            ber->ber_usertag = 0;
    }

    va_end( ap );

    return( rc );
}