ldap/util/line64.c

/*
 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * The contents of this file are subject to the Netscape Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/NPL/
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation. Portions created by Netscape are
 * Copyright (C) 1998-1999 Netscape Communications Corporation. All
 * Rights Reserved.
 *
 * Contributor(s):
 */

/* line64.c - routines for dealing with the slapd line format */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#ifndef macintosh
#include <sys/types.h>
#endif
#ifdef _WIN32
#include <windows.h>
#elif !defined( macintosh )
#include <sys/socket.h>
#endif
#include "ldaplog.h"
#include "ldif.h"

#ifndef isascii
#define isascii( c )    (!((c) & ~0177))
#endif

#define RIGHT2          0x03
#define RIGHT4          0x0f
#define CONTINUED_LINE_MARKER   '\001'

#define ISBLANK(c) ((c) == ' ' || (c) == '\t' || (c) == '\n') /* not "\r\v\f" */

#define LDIF_OPT_ISSET( value, opt )    (((value) & (opt)) != 0 )

static char nib2b64[0x40] =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

static unsigned char b642nib[0x80] = {
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f,
    0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
    0x3c, 0x3d, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
    0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
    0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
    0x17, 0x18, 0x19, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
    0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
    0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
    0x31, 0x32, 0x33, 0xff, 0xff, 0xff, 0xff, 0xff
};

static int ldif_base64_encode_internal( unsigned char *src, char *dst, int srclen,
    int lenused, int wraplen );

/*
 * str_parse_line - takes a line of the form "type:[:] value" and splits it
 * into components "type" and "value".  if a double colon separates type from
 * value, then value is encoded in base 64, and parse_line un-decodes it
 * (in place) before returning.
 */

int
str_parse_line(
    char    *line,
    char    **type,
    char    **value,
    int     *vlen
)
{
    char    *p, *s, *d;
    int b64;

    /* skip any leading space */
    while ( ISBLANK( *line ) ) {
        line++;
    }
    *type = line;

    for ( s = line; *s && *s != ':'; s++ )
        ;   /* NULL */
    if ( *s == '\0' ) {

        /* Comment-out while we address calling libldif from ns-back-ldbm
            on NT. 1 of 3 */
#if defined( _WIN32 )
        /*
#endif
         LDAPDebug( LDAP_DEBUG_PARSE, "str_parse_line: missing ':' "
            "on line \"%s\"\n", line, 0, 0 );
#if defined( _WIN32 )
        */
#endif
        return( -1 );
    }

    /* trim any space between type and : */
    for ( p = s - 1; p > line && ISBLANK( *p ); p-- ) {
        *p = '\0';
    }
    *s++ = '\0';

    /* check for double : - indicates base 64 encoded value */
    if ( *s == ':' ) {
        s++;
        b64 = 1;

    /* single : - normally encoded value */
    } else {
        b64 = 0;
    }

    /* skip space between : and value */
    while ( ISBLANK( *s ) ) {
        s++;
    }

    /*
     * If no value is present, return a zero-length string for
     * *value, with *vlen set to zero.
     */
    if ( *s == '\0' ) {
        *value = s;
        *vlen = 0;
        return( 0 );
    }

    /* check for continued line markers that should be deleted */
    for ( p = s, d = s; *p; p++ ) {
        if ( *p != CONTINUED_LINE_MARKER )
            *d++ = *p;
    }
    *d = '\0';

    *value = s;
    if ( b64 ) {
        if (( *vlen = ldif_base64_decode( s, (unsigned char *)s ))
            < 0 ) {
            /* Comment-out while we address calling libldif from ns-back-ldbm
                on NT. 3 of 3 */
#if defined( _WIN32 )
        /*
#endif
             LDAPDebug( LDAP_DEBUG_ANY,
                "str_parse_line: invalid base 64 char on line \"%s\"\n",
                line, 0, 0 );
#if defined( _WIN32 )
        */
#endif
            return( -1 );
        }
        s[ *vlen ] = '\0';
    } else {
        *vlen = (int) (d - s);
    }

    return( 0 );
}


/*
 * ldif_base64_decode - take the BASE64-encoded characters in "src"
 * (a zero-terminated string) and decode them into the the buffer "dst".
 * "src" and "dst" can be the same if in-place decoding is desired.
 * "dst" must be large enough to hold the decoded octets.  No more than
 *  3 * strlen( src ) / 4 bytes will be produced.
 * "dst" may contain zero octets anywhere within it, but it is not
 *  zero-terminated by this function.
 *
 * The number of bytes copied to "dst" is returned if all goes well.
 * -1 is returned if the BASE64 encoding in "src" is invalid.
 */

int
ldif_base64_decode( char *src, unsigned char *dst )
{
    char        *p, *stop;
    unsigned char   nib, *byte;
    int     i, len;

    stop = strchr( src, '\0' );
    byte = dst;
    for ( p = src, len = 0; p < stop; p += 4, len += 3 ) {
        for ( i = 0; i < 4; i++ ) {
            if ( p[i] != '=' && (p[i] & 0x80 ||
                b642nib[ p[i] & 0x7f ] > 0x3f) ) {
                return( -1 );
            }
        }

        /* first digit */
        nib = b642nib[ p[0] & 0x7f ];
        byte[0] = nib << 2;

        /* second digit */
        nib = b642nib[ p[1] & 0x7f ];
        byte[0] |= nib >> 4;

        /* third digit */
        if ( p[2] == '=' ) {
            len += 1;
            break;
        }
        byte[1] = (nib & RIGHT4) << 4;
        nib = b642nib[ p[2] & 0x7f ];
        byte[1] |= nib >> 2;

        /* fourth digit */
        if ( p[3] == '=' ) {
            len += 2;
            break;
        }
        byte[2] = (nib & RIGHT2) << 6;
        nib = b642nib[ p[3] & 0x7f ];
        byte[2] |= nib;

        byte += 3;
    }

    return( len );
}

/*
 * str_getline - return the next "line" (minus newline) of input from a
 * string buffer of lines separated by newlines, terminated by \n\n
 * or \0.  this routine handles continued lines, bundling them into
 * a single big line before returning.  if a line begins with a white
 * space character, it is a continuation of the previous line. the white
 * space character (nb: only one char), and preceding newline are changed
 * into CONTINUED_LINE_MARKER chars, to be deleted later by the
 * str_parse_line() routine above.
 *
 * it takes a pointer to a pointer to the buffer on the first call,
 * which it updates and must be supplied on subsequent calls.
 *
 * XXX need to update this function to also support <CR><LF> as EOL.
 * XXX supports <CR><LF> as of 07/29/1998 (richm)
 */

char *
str_getline( char **next )
{
    char    *l;
    char    c;
    char    *p;

    if ( *next == NULL || **next == '\n' || **next == '\0' ) {
        return( NULL );
    }

    while ( **next == '#' ) {   /* skip comment lines */
        if (( *next = strchr( *next, '\n' )) == NULL ) {
            return( NULL );
        }
        (*next)++;
    }

    l = *next;
    while ( (*next = strchr( *next, '\n' )) != NULL ) {
        p = *next - 1; /* pointer to character previous to the newline */
        c = *(*next + 1); /* character after the newline */
        if ( ISBLANK( c ) && c != '\n' ) {
            /* DOS EOL is \r\n, so if the character before */
            /* the \n is \r, continue it too */
            if (*p == '\r')
                *p = CONTINUED_LINE_MARKER;
            **next = CONTINUED_LINE_MARKER;
            *(*next+1) = CONTINUED_LINE_MARKER;
        } else {
            /* DOS EOL is \r\n, so if the character before */
            /* the \n is \r, null it too */
            if (*p == '\r')
                *p = '\0';
            *(*next)++ = '\0';
            break;
        }
        (*next)++;
    }

    return( l );
}


#define LDIF_SAFE_CHAR( c )     ( (c) != '\r' && (c) != '\n' )
#define LDIF_CONSERVATIVE_CHAR( c ) ( LDIF_SAFE_CHAR(c) && isascii((c)) \
                     && ( isprint((c)) || (c) == '\t' ))
#define LDIF_SAFE_INITCHAR( c )     ( LDIF_SAFE_CHAR(c) && (c) != ':' \
                     && (c) != ' ' && (c) != '<' )
#define LDIF_CONSERVATIVE_INITCHAR( c ) ( LDIF_SAFE_INITCHAR( c ) && \
                     ! ( isascii((c)) && isspace((c))))
#define LDIF_CONSERVATIVE_FINALCHAR( c ) ( (c) != ' ' )


void
ldif_put_type_and_value_with_options( char **out, char *t, char *val,
    int vlen, unsigned long options )
{
    unsigned char   *p, *byte, *stop;
    char        *save;
    int     b64, len, savelen, wraplen;
    len = 0;

    if ( LDIF_OPT_ISSET( options, LDIF_OPT_NOWRAP )) {
        wraplen = -1;
    } else {
        wraplen = LDIF_MAX_LINE_WIDTH;
    }

    /* put the type + ": " */
    for ( p = (unsigned char *) t; *p; p++, len++ ) {
        *(*out)++ = *p;
    }
    *(*out)++ = ':';
    len++;
    if ( LDIF_OPT_ISSET( options, LDIF_OPT_VALUE_IS_URL )) {
        *(*out)++ = '<';    /* add '<' for URLs */
        len++;
    }
    save = *out;
    savelen = len;
    b64 = 0;

    stop = (unsigned char *)val;
    if ( val && vlen > 0 ) {
        *(*out)++ = ' ';
        stop = (unsigned char *) (val + vlen);
        if ( LDIF_OPT_ISSET( options, LDIF_OPT_MINIMAL_ENCODING )) {
            if ( !LDIF_SAFE_INITCHAR( val[0] )) {
                b64 = 1;
            }
        } else {
            if ( !LDIF_CONSERVATIVE_INITCHAR( val[0] ) ||
                 !LDIF_CONSERVATIVE_FINALCHAR( val[vlen-1] )) {
                b64 = 1;
            }
        }
    }

    if ( !b64 ) {
        for ( byte = (unsigned char *) val; byte < stop;
            byte++, len++ ) {
            if ( LDIF_OPT_ISSET( options,
                LDIF_OPT_MINIMAL_ENCODING )) {
                if ( !LDIF_SAFE_CHAR( *byte )) {
                    b64 = 1;
                    break;
                }
            } else if ( !LDIF_CONSERVATIVE_CHAR( *byte )) {
                b64 = 1;
                break;
            }

            if ( wraplen != -1 && len > wraplen ) {
                *(*out)++ = '\n';
                *(*out)++ = ' ';
                len = 1;
            }
            *(*out)++ = *byte;
        }
    }

    if ( b64 ) {
        *out = save;
        *(*out)++ = ':';
        *(*out)++ = ' ';
        len = ldif_base64_encode_internal( (unsigned char *)val, *out, vlen,
            savelen + 2, wraplen );
        *out += len;
    }

    *(*out)++ = '\n';
}

void
ldif_put_type_and_value( char **out, char *t, char *val, int vlen )
{
    ldif_put_type_and_value_with_options( out, t, val, vlen, 0 );
}

void
ldif_put_type_and_value_nowrap( char **out, char *t, char *val, int vlen )
{
    ldif_put_type_and_value_with_options( out, t, val, vlen, LDIF_OPT_NOWRAP );
}

/*
 * ldif_base64_encode_internal - encode "srclen" bytes in "src", place BASE64
 * encoded bytes in "dst" and return the length of the BASE64
 * encoded string.  "dst" is also zero-terminated by this function.
 *
 * If "lenused" >= 0, newlines will be included in "dst" and "lenused" if
 * appropriate.  "lenused" should be a count of characters already used
 * on the current line.  The LDIF lines we create will contain at most
 * "wraplen" characters on each line, unless "wraplen" is -1, in which
 * case output line length is unlimited.
 *
 * If "lenused" < 0, no newlines will be included, and the LDIF_BASE64_LEN()
 * macro can be used to determine how many bytes will be placed in "dst."
 */

static int
ldif_base64_encode_internal( unsigned char *src, char *dst, int srclen, int lenused, int wraplen )
{
    unsigned char   *byte, *stop;
    unsigned char   buf[3];
    char        *out;
    unsigned long   bits;
    int     i, pad, len;

    len = 0;
    out = dst;
    stop = src + srclen;

    /* convert to base 64 (3 bytes => 4 base 64 digits) */
    for ( byte = src; byte < stop - 2; byte += 3 ) {
        bits = (byte[0] & 0xff) << 16;
        bits |= (byte[1] & 0xff) << 8;
        bits |= (byte[2] & 0xff);

        for ( i = 0; i < 4; i++, bits <<= 6 ) {
            if ( wraplen != -1 &&  lenused >= 0 && lenused++ > wraplen ) {
                *out++ = '\n';
                *out++ = ' ';
                lenused = 2;
            }

            /* get b64 digit from high order 6 bits */
            *out++ = nib2b64[ (bits & 0xfc0000L) >> 18 ];
        }
    }

    /* add padding if necessary */
    if ( byte < stop ) {
        for ( i = 0; byte + i < stop; i++ ) {
            buf[i] = byte[i];
        }
        for ( pad = 0; i < 3; i++, pad++ ) {
            buf[i] = '\0';
        }
        byte = buf;
        bits = (byte[0] & 0xff) << 16;
        bits |= (byte[1] & 0xff) << 8;
        bits |= (byte[2] & 0xff);

        for ( i = 0; i < 4; i++, bits <<= 6 ) {
            if ( wraplen != -1 && lenused >= 0 && lenused++ > wraplen ) {
                *out++ = '\n';
                *out++ = ' ';
                lenused = 2;
            }

            if (( i == 3 && pad > 0 ) || ( i == 2 && pad == 2 )) {
                /* Pad as appropriate */
                *out++ = '=';
            } else {
                /* get b64 digit from low order 6 bits */
                *out++ = nib2b64[ (bits & 0xfc0000L) >> 18 ];
            }
        }
    }

    *out = '\0';

    return( out - dst );
}

int
ldif_base64_encode( unsigned char *src, char *dst, int srclen, int lenused )
{
    return ldif_base64_encode_internal( src, dst, srclen, lenused, LDIF_MAX_LINE_WIDTH );
}

int
ldif_base64_encode_nowrap( unsigned char *src, char *dst, int srclen, int lenused )
{
    return ldif_base64_encode_internal( src, dst, srclen, lenused, -1 );
}


/*
 * return malloc'd, zero-terminated LDIF line
 */
char *
ldif_type_and_value_with_options( char *type, char *val, int vlen,
    unsigned long options )
{
    char    *buf, *p;
    int     tlen;

    tlen = strlen( type );
    if (( buf = (char *)malloc( LDIF_SIZE_NEEDED( tlen, vlen ) + 1 )) !=
        NULL ) {
    p = buf;
    ldif_put_type_and_value_with_options( &p, type, val, vlen, options );
    *p = '\0';
    }

    return( buf );
}

char *
ldif_type_and_value( char *type, char *val, int vlen )
{
    return ldif_type_and_value_with_options( type, val, vlen, 0 );
}

char *
ldif_type_and_value_nowrap( char *type, char *val, int vlen )
{
    return ldif_type_and_value_with_options( type, val, vlen, LDIF_OPT_NOWRAP );
}

/*
 * ldif_get_entry - read the next ldif entry from the FILE referenced
 * by fp. return a pointer to a malloc'd, null-terminated buffer. also
 * returned is the last line number read, in *lineno.
 */
char *
ldif_get_entry( FILE *fp, int *lineno )
{
    char    line[BUFSIZ];
    char    *buf;
    int max, cur, len, gotsome;

    buf = NULL;
    max = cur = gotsome = 0;
    while ( fgets( line, sizeof(line), fp ) != NULL ) {
        if ( lineno != NULL ) {
            (*lineno)++;
        }
        /* ldif entries are terminated by a \n on a line by itself */
        if ( line[0] == '\0' || line[0] == '\n'
#if !defined( XP_WIN32 )
             || ( line[0] == '\r' && line[1] == '\n' ) /* DOS format */
#endif
           ) {
            if ( gotsome ) {
                break;
            } else {
                continue;
            }
        } else if ( line[0] == '#' ) {
            continue;
        }
        gotsome = 1;
        len = strlen( line );
#if !defined( XP_WIN32 )
        /* DOS format */
        if ( len > 0 && line[len-1] == '\r' ) {
            --len;
            line[len] = '\0';
        } else if ( len > 1 && line[len-2] == '\r' && line[len-1] == '\n' ) {
            --len;
            line[len-1] = line[len];
            line[len] = '\0';
        }
#endif
        while ( cur + (len + 1) > max ) {
            if ( buf == NULL ) {
                max += BUFSIZ;
                buf = (char *) malloc( max );
            } else {
                max *= 2;
                buf = (char *) realloc( buf, max );
            }
            if ( buf == NULL ) {
                return( NULL );
            }
        }

        memcpy( buf + cur, line, len + 1 );
        cur += len;
    }

    return( buf );
}