ldap/ber/decode.c

/*
 * Copyright 2001-2002 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


#pragma ident   "%Z%%M% %I% %E% SMI"


/* -*- 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.
 */

/* decode.c - ber input decoding routines */

#include "lber-int.h"
LDAP_API(void) LDAP_CALL ber_svecfree( char **vals );

/*
 * Note: ber_get_tag() only uses the ber_end and ber_ptr elements of ber.
 * If that changes, the ber_peek_tag() and/or ber_skip_tag() implementations
 * will need to be changed.
 */
/* return the tag - LBER_DEFAULT returned means trouble */
ber_tag_t
LDAP_CALL
ber_get_tag( BerElement *ber )
{
    unsigned char   xbyte;
    ber_tag_t   tag;
    char        *tagp;
    int     i;

    if ( ber_read( ber, (char *) &xbyte, 1 ) != 1 )
        return( LBER_DEFAULT );

    if ( (xbyte & LBER_BIG_TAG_MASK) != LBER_BIG_TAG_MASK )
        return( (ber_uint_t) xbyte );

    tagp = (char *) &tag;
    tagp[0] = xbyte;
    for ( i = 1; i < sizeof(ber_int_t); i++ ) {
        if ( ber_read( ber, (char *) &xbyte, 1 ) != 1 )
            return( LBER_DEFAULT );

        tagp[i] = xbyte;

        if ( ! (xbyte & LBER_MORE_TAG_MASK) )
            break;
    }

    /* tag too big! */
    if ( i == sizeof(ber_int_t) )
        return( LBER_DEFAULT );

    /* want leading, not trailing 0's */
    return( tag >> (sizeof(ber_int_t) - i - 1) );
}

/*
 * Note: ber_skip_tag() only uses the ber_end and ber_ptr elements of ber.
 * If that changes, the implementation of ber_peek_tag() will need to
 * be changed.
 */
ber_tag_t
LDAP_CALL
ber_skip_tag( BerElement *ber, ber_len_t *len )
{
    ber_tag_t   tag;
    unsigned char   lc;
    int     noctets, diff;
    ber_len_t   netlen;

    /*
     * Any ber element looks like this: tag length contents.
     * Assuming everything's ok, we return the tag byte (we
     * can assume a single byte), and return the length in len.
     *
     * Assumptions:
     *  1) definite lengths
     *  2) primitive encodings used whenever possible
     */

    /*
     * First, we read the tag.
     */

    if ( (tag = ber_get_tag( ber )) == LBER_DEFAULT )
        return( LBER_DEFAULT );

    /*
     * Next, read the length.  The first byte contains the length of
     * the length.  If bit 8 is set, the length is the long form,
     * otherwise it's the short form.  We don't allow a length that's
     * greater than what we can hold in an unsigned long.
     */

    *len = netlen = 0;
    if ( ber_read( ber, (char *) &lc, 1 ) != 1 )
        return( LBER_DEFAULT );
    if ( lc & 0x80 ) {
        noctets = (lc & 0x7f);
        if ( noctets > sizeof(ber_uint_t) )
            return( LBER_DEFAULT );
        diff = sizeof(ber_int_t) - noctets;
        if ( ber_read( ber, (char *) &netlen + diff, noctets )
            != noctets )
            return( LBER_DEFAULT );
        *len = LBER_NTOHL( netlen );
    } else {
        *len = lc;
    }

    return( tag );
}


/*
 * Note: Previously, we passed the "ber" parameter directly to ber_skip_tag(),
 * saving and restoring the ber_ptr element only.  We now take advantage
 * of the fact that the only ber structure elements touched by ber_skip_tag()
 * are ber_end and ber_ptr.  If that changes, this code must change too.
 */
ber_tag_t
LDAP_CALL
ber_peek_tag( BerElement *ber, ber_len_t *len )
{
    BerElement  bercopy;

    bercopy.ber_end = ber->ber_end;
    bercopy.ber_ptr = ber->ber_ptr;
    return( ber_skip_tag( &bercopy, len ));
}

static int
ber_getnint( BerElement *ber, ber_int_t *num, ber_slen_t len )
{
    int i;
    ber_int_t value;
    unsigned char buffer[sizeof(ber_int_t)];
    /*
     * The tag and length have already been stripped off.  We should
     * be sitting right before len bytes of 2's complement integer,
     * ready to be read straight into an int.  We may have to sign
     * extend after we read it in.
     */

    if ( len > sizeof(ber_slen_t) )
        return( -1 );

    /* read into the low-order bytes of netnum */
    if ( ber_read( ber, (char *) buffer, len ) != len )
        return( -1 );

    /* This sets the required sign extension */
    if ( len != 0) {
        value = 0x80 & buffer[0] ? (LBER_FUNC_VALUE) : 0;
    } else {
        value = 0;
    }

    for ( i = 0; i < len; i++ )
      value = (value << 8) | buffer[i];

    *num = value;

    return( len );
}

ber_tag_t
LDAP_CALL
ber_get_int( BerElement *ber, ber_int_t *num )
{
    ber_tag_t   tag;
    ber_len_t   len;

    if ( (tag = ber_skip_tag( ber, &len )) == LBER_DEFAULT )
        return( LBER_DEFAULT );

    /*
     * len is being demoted to a long here --  possible conversion error
     */

    if ( ber_getnint( ber, num, (int)len ) != (ber_slen_t)len )
        return( LBER_DEFAULT );
    else
        return( tag );
}

ber_tag_t
LDAP_CALL
ber_get_stringb( BerElement *ber, char *buf, ber_len_t *len )
{
    ber_len_t   datalen;
    ber_tag_t   tag;
#ifdef STR_TRANSLATION
    char        *transbuf;
#endif /* STR_TRANSLATION */

    if ( (tag = ber_skip_tag( ber, &datalen )) == LBER_DEFAULT )
        return( LBER_DEFAULT );
    if ( datalen > (*len - 1) )
        return( LBER_DEFAULT );

    /*
     * datalen is being demoted to a long here --  possible conversion error
     */

    if ( ber_read( ber, buf, datalen ) != (ber_slen_t) datalen )
        return( LBER_DEFAULT );

    buf[datalen] = '\0';

#ifdef STR_TRANSLATION
    if ( datalen > 0 && ( ber->ber_options & LBER_OPT_TRANSLATE_STRINGS )
        != 0 && ber->ber_decode_translate_proc != NULL ) {
        transbuf = buf;
        ++datalen;
        if ( (*(ber->ber_decode_translate_proc))( &transbuf, &datalen,
            0 ) != 0 ) {
            return( LBER_DEFAULT );
        }
        if ( datalen > *len ) {
            NSLBERI_FREE( transbuf );
            return( LBER_DEFAULT );
        }
        SAFEMEMCPY( buf, transbuf, datalen );
        NSLBERI_FREE( transbuf );
        --datalen;
    }
#endif /* STR_TRANSLATION */

    *len = datalen;
    return( tag );
}

ber_tag_t
LDAP_CALL
ber_get_stringa( BerElement *ber, char **buf )
{
    ber_len_t   datalen;
    ber_tag_t   tag;

    if ( (tag = ber_skip_tag( ber, &datalen )) == LBER_DEFAULT )
        return( LBER_DEFAULT );

    if ( (*buf = (char *)NSLBERI_MALLOC( (size_t)datalen + 1 )) == NULL )
        return( LBER_DEFAULT );

    /*
     * datalen is being demoted to a long here --  possible conversion error
     */
    if ( ber_read( ber, *buf, datalen ) != (ber_slen_t) datalen )
        return( LBER_DEFAULT );
    (*buf)[datalen] = '\0';

#ifdef STR_TRANSLATION
    if ( datalen > 0 && ( ber->ber_options & LBER_OPT_TRANSLATE_STRINGS )
        != 0 && ber->ber_decode_translate_proc != NULL ) {
        ++datalen;
        if ( (*(ber->ber_decode_translate_proc))( buf, &datalen, 1 )
            != 0 ) {
            NSLBERI_FREE( *buf );
            return( LBER_DEFAULT );
        }
    }
#endif /* STR_TRANSLATION */

    return( tag );
}

ber_tag_t
LDAP_CALL
ber_get_stringal( BerElement *ber, struct berval **bv )
{
    ber_len_t   len;
    ber_tag_t   tag;

    if ( (*bv = (struct berval *)NSLBERI_MALLOC( sizeof(struct berval) ))
        == NULL ) {
        return( LBER_DEFAULT );
    }

    if ( (tag = ber_skip_tag( ber, &len )) == LBER_DEFAULT ) {
        return( LBER_DEFAULT );
    }

    if ( ((*bv)->bv_val = (char *)NSLBERI_MALLOC( (size_t)len + 1 ))
        == NULL ) {
        return( LBER_DEFAULT );
    }

    /*
     * len is being demoted to a long here --  possible conversion error
     */
    if ( ber_read( ber, (*bv)->bv_val, len ) != (ber_slen_t) len )
        return( LBER_DEFAULT );
    ((*bv)->bv_val)[len] = '\0';
    (*bv)->bv_len = len;

#ifdef STR_TRANSLATION
    if ( len > 0 && ( ber->ber_options & LBER_OPT_TRANSLATE_STRINGS ) != 0
        && ber->ber_decode_translate_proc != NULL ) {
        ++len;
        if ( (*(ber->ber_decode_translate_proc))( &((*bv)->bv_val),
            &len, 1 ) != 0 ) {
            NSLBERI_FREE( (*bv)->bv_val );
            return( LBER_DEFAULT );
        }
        (*bv)->bv_len = len - 1;
    }
#endif /* STR_TRANSLATION */

    return( tag );
}

ber_tag_t
LDAP_CALL
ber_get_bitstringa( BerElement *ber, char **buf, ber_len_t *blen )
{
    ber_len_t   datalen;
    ber_tag_t   tag;
    unsigned char   unusedbits;

    if ( (tag = ber_skip_tag( ber, &datalen )) == LBER_DEFAULT )
        return( LBER_DEFAULT );
    --datalen;

    if ( (*buf = (char *)NSLBERI_MALLOC( (size_t)datalen )) == NULL )
        return( LBER_DEFAULT );

    if ( ber_read( ber, (char *)&unusedbits, 1 ) != 1 )
        return( LBER_DEFAULT );

    /*
     * datalen is being demoted to a long here --  possible conversion error
     */
    if ( ber_read( ber, *buf, datalen ) != (ber_slen_t) datalen )
        return( LBER_DEFAULT );

    *blen = datalen * 8 - unusedbits;
    return( tag );
}

ber_tag_t
LDAP_CALL
ber_get_null( BerElement *ber )
{
    ber_len_t   len;
    ber_tag_t tag;

    if ( (tag = ber_skip_tag( ber, &len )) == LBER_DEFAULT )
        return( LBER_DEFAULT );

    if ( len != 0 )
        return( LBER_DEFAULT );

    return( tag );
}

ber_tag_t
LDAP_CALL
ber_get_boolean( BerElement *ber, int *boolval )
{
    ber_int_t   longbool;
    int     rc;

    rc = ber_get_int( ber, &longbool );
    *boolval = longbool;

    return( rc );
}

ber_tag_t
LDAP_CALL
ber_first_element( BerElement *ber, ber_len_t *len, char **last )
{
    /* skip the sequence header, use the len to mark where to stop */
    if ( ber_skip_tag( ber, len ) == LBER_DEFAULT ) {
        return( LBER_ERROR );
    }

    *last = ber->ber_ptr + *len;

    if ( *last == ber->ber_ptr ) {
        return( LBER_END_OF_SEQORSET );
    }

    return( ber_peek_tag( ber, len ) );
}

ber_tag_t
LDAP_CALL
ber_next_element( BerElement *ber, ber_len_t *len, char *last )
{
    if ( ber->ber_ptr == last ) {
        return( LBER_END_OF_SEQORSET );
    }

    return( ber_peek_tag( ber, len ) );
}

/* VARARGS */
ber_tag_t
LDAP_C
ber_scanf( BerElement *ber, const char *fmt, ... )
{
    va_list     ap;
    char        *last, *p;
    char        *s, **ss, ***sss;
    struct berval   ***bv, **bvp, *bval;
    int     *i, j;
    ber_int_t   *l, rc, tag;
    ber_tag_t   *t;
    ber_len_t   len;
    size_t      array_size;

    va_start( ap, fmt );

#ifdef LDAP_DEBUG
    if ( lber_debug & 64 ) {
        char msg[80];
        sprintf( msg, "ber_scanf fmt (%s) ber:\n", fmt );
        ber_err_print( msg );
        ber_dump( ber, 1 );
    }
#endif

    for ( rc = 0, p = (char *)fmt; *p && rc != LBER_DEFAULT; p++ ) {
        switch ( *p ) {
        case 'a':   /* octet string - allocate storage as needed */
            ss = va_arg( ap, char ** );
            rc = ber_get_stringa( ber, ss );
            break;

        case 'b':   /* boolean */
            i = va_arg( ap, int * );
            rc = ber_get_boolean( ber, i );
            break;

        case 'e':   /* enumerated */
        case 'i':   /* int */
            l = va_arg( ap, ber_slen_t * );
            rc = ber_get_int( ber, l );
            break;

        case 'l':   /* length of next item */
            l = va_arg( ap, ber_slen_t * );
            rc = ber_peek_tag( ber, (ber_len_t *)l );
            break;

        case 'n':   /* null */
            rc = ber_get_null( ber );
            break;

        case 's':   /* octet string - in a buffer */
            s = va_arg( ap, char * );
            l = va_arg( ap, ber_slen_t * );
            rc = ber_get_stringb( ber, s, (ber_len_t *)l );
            break;

        case 'o':   /* octet string in a supplied berval */
            bval = va_arg( ap, struct berval * );
            ber_peek_tag( ber, &bval->bv_len );
            rc = ber_get_stringa( ber, &bval->bv_val );
            break;

        case 'O':   /* octet string - allocate & include length */
            bvp = va_arg( ap, struct berval ** );
            rc = ber_get_stringal( ber, bvp );
            break;

        case 'B':   /* bit string - allocate storage as needed */
            ss = va_arg( ap, char ** );
            l = va_arg( ap, ber_slen_t * ); /* for length, in bits */
            rc = ber_get_bitstringa( ber, ss, (ber_len_t *)l );
            break;

        case 't':   /* tag of next item */
            t = va_arg( ap, ber_tag_t * );
            *t = rc = ber_peek_tag( ber, &len );
            break;

        case 'T':   /* skip tag of next item */
            t = va_arg( ap, ber_tag_t * );
            *t = rc = ber_skip_tag( ber, &len );
            break;

        case 'v':   /* sequence of strings */
            sss = va_arg( ap, char *** );
            *sss = NULL;
            j = 0;
            array_size = 0;
            for ( tag = ber_first_element( ber, &len, &last );
                tag != LBER_DEFAULT && tag != LBER_END_OF_SEQORSET
                && rc != LBER_DEFAULT;
                tag = ber_next_element( ber, &len, last ) ) {
                if ( *sss == NULL ) {
                    /* Make room for at least 15 strings */
                    *sss = (char **)NSLBERI_MALLOC(16 * sizeof(char *) );
                    array_size = 16;
                } else {
                    if ( (size_t)(j+2) > array_size) {
                    /* We'v overflowed our buffer */
                    *sss = (char **)NSLBERI_REALLOC( *sss, (array_size * 2) * sizeof(char *) );
                    array_size = array_size * 2;
                    }
                }
                rc = ber_get_stringa( ber, &((*sss)[j]) );
                j++;
            }
            if ( rc != LBER_DEFAULT &&
                tag != LBER_END_OF_SEQORSET ) {
                rc = LBER_DEFAULT;
            }
            if ( j > 0 )
                (*sss)[j] = NULL;
            break;

        case 'V':   /* sequence of strings + lengths */
            bv = va_arg( ap, struct berval *** );
            *bv = NULL;
            j = 0;
            for ( tag = ber_first_element( ber, &len, &last );
                tag != LBER_DEFAULT && tag != LBER_END_OF_SEQORSET
                && rc != LBER_DEFAULT;
                tag = ber_next_element( ber, &len, last ) ) {
                if ( *bv == NULL ) {
                    *bv = (struct berval **)NSLBERI_MALLOC(
                        2 * sizeof(struct berval *) );
                } else {
                    *bv = (struct berval **)NSLBERI_REALLOC(
                        *bv,
                        (j + 2) * sizeof(struct berval *) );
                }
                rc = ber_get_stringal( ber, &((*bv)[j]) );
                j++;
            }
            if ( rc != LBER_DEFAULT &&
                tag != LBER_END_OF_SEQORSET ) {
                rc = LBER_DEFAULT;
            }
            if ( j > 0 )
                (*bv)[j] = NULL;
            break;

        case 'x':   /* skip the next element - whatever it is */
            if ( (rc = ber_skip_tag( ber, &len )) == LBER_DEFAULT )
                break;
            ber->ber_ptr += len;
            break;

        case '{':   /* begin sequence */
        case '[':   /* begin set */
            if ( *(p + 1) != 'v' && *(p + 1) != 'V' )
                rc = ber_skip_tag( ber, &len );
            break;

        case '}':   /* end sequence */
        case ']':   /* end set */
            break;

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


    va_end( ap );
        if (rc == LBER_DEFAULT) {
          va_start( ap, fmt );
          for ( p--; fmt < p && *fmt; fmt++ ) {
                switch ( *fmt ) {
                case 'a':       /* octet string - allocate storage as needed */
                        ss = va_arg( ap, char ** );
                        NSLBERI_FREE(*ss);
                        *ss = NULL;
                        break;

                case 'b':       /* boolean */
                        i = va_arg( ap, int * );
                        break;

                case 'e':       /* enumerated */
                case 'i':       /* int */
                        l = va_arg( ap, ber_slen_t * );
                        break;

                case 'l':       /* length of next item */
                        l = va_arg( ap, ber_slen_t * );
                        break;

                case 'n':       /* null */
                        break;

                case 's':       /* octet string - in a buffer */
                        s = va_arg( ap, char * );
                        l = va_arg( ap, ber_slen_t * );
                        break;

                case 'o':       /* octet string in a supplied berval */
                        bval = va_arg( ap, struct berval * );
                        if (bval->bv_val) NSLBERI_FREE(bval->bv_val);
                        memset(bval, 0, sizeof(struct berval));
                        break;

                case 'O':       /* octet string - allocate & include length */
                        bvp = va_arg( ap, struct berval ** );
                        ber_bvfree(*bvp);
                        bvp = NULL;
                        break;

                case 'B':       /* bit string - allocate storage as needed */
                        ss = va_arg( ap, char ** );
                        l = va_arg( ap, ber_slen_t * ); /* for length, in bits */
                        if (*ss) NSLBERI_FREE(*ss);
                        *ss = NULL;
                        break;

                case 't':       /* tag of next item */
                        t = va_arg( ap, ber_tag_t * );
                        break;
                case 'T':       /* skip tag of next item */
                        t = va_arg( ap, ber_tag_t * );
                        break;

                case 'v':       /* sequence of strings */
                        sss = va_arg( ap, char *** );
                        ber_svecfree(*sss);
                        *sss = NULL;
                        break;

                case 'V':       /* sequence of strings + lengths */
                        bv = va_arg( ap, struct berval *** );
                        ber_bvecfree(*bv);
                        *bv = NULL;
                        break;

                case 'x':       /* skip the next element - whatever it is */
                        break;

                case '{':       /* begin sequence */
                case '[':       /* begin set */
                        break;

                case '}':       /* end sequence */
                case ']':       /* end set */
                        break;

                default:
                        break;
                }
          } /* for */
          va_end( ap );
        } /* if */


    return( rc );
}

void
LDAP_CALL
ber_bvfree( struct berval *bv )
{
    if ( bv != NULL ) {
        if ( bv->bv_val != NULL ) {
            NSLBERI_FREE( bv->bv_val );
        }
        NSLBERI_FREE( (char *) bv );
    }
}

void
LDAP_CALL
ber_bvecfree( struct berval **bv )
{
    int i;

    if ( bv != NULL ) {
        for ( i = 0; bv[i] != NULL; i++ ) {
            ber_bvfree( bv[i] );
        }
        NSLBERI_FREE( (char *) bv );
    }
}

struct berval *
LDAP_CALL
ber_bvdup( const struct berval *bv )
{
    struct berval   *new;

    if ( (new = (struct berval *)NSLBERI_MALLOC( sizeof(struct berval) ))
        == NULL ) {
        return( NULL );
    }
    if ( bv->bv_val == NULL ) {
        new->bv_val = NULL;
        new->bv_len = 0;
    } else {
        if ( (new->bv_val = (char *)NSLBERI_MALLOC( bv->bv_len + 1 ))
        == NULL ) {
            return( NULL );
        }
        SAFEMEMCPY( new->bv_val, bv->bv_val, (size_t) bv->bv_len );
        new->bv_val[bv->bv_len] = '\0';
        new->bv_len = bv->bv_len;
    }

    return( new );
}

void
LDAP_CALL
ber_svecfree( char **vals )
{
        int     i;

        if ( vals == NULL )
                return;
        for ( i = 0; vals[i] != NULL; i++ )
                NSLBERI_FREE( vals[i] );
        NSLBERI_FREE( (char *) vals );
}

#ifdef STR_TRANSLATION
void
LDAP_CALL
ber_set_string_translators(
    BerElement      *ber,
    BERTranslateProc    encode_proc,
    BERTranslateProc    decode_proc
)
{
    ber->ber_encode_translate_proc = encode_proc;
    ber->ber_decode_translate_proc = decode_proc;
}
#endif /* STR_TRANSLATION */