/*
 * 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 );
}