root/ext/mbstring/libmbfl/filters/mbfilter_base64.c

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DEFINITIONS

This source file includes following definitions.
  1. mbfl_filt_conv_base64enc
  2. mbfl_filt_conv_base64enc_flush
  3. mbfl_filt_conv_base64dec
  4. mbfl_filt_conv_base64dec_flush

 /*
 * "streamable kanji code filter and converter"
 * Copyright (c) 1998-2002 HappySize, Inc. All rights reserved.
 *
 * LICENSE NOTICES
 *
 * This file is part of "streamable kanji code filter and converter",
 * which is distributed under the terms of GNU Lesser General Public 
 * License (version 2) as published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with "streamable kanji code filter and converter";
 * if not, write to the Free Software Foundation, Inc., 59 Temple Place,
 * Suite 330, Boston, MA  02111-1307  USA
 *
 * The author of this file:
 *
 */
/*
 * The source code included in this files was separated from mbfilter.c
 * by Moriyoshi Koizumi <moriyoshi@php.net> on 4 Dec 2002. The file
 * mbfilter.c is included in this package .
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "mbfilter.h"
#include "mbfilter_base64.h"

const mbfl_encoding mbfl_encoding_base64 = {
        mbfl_no_encoding_base64,
        "BASE64",
        "BASE64",
        NULL,
        NULL,
        MBFL_ENCTYPE_SBCS
};

const struct mbfl_convert_vtbl vtbl_8bit_b64 = {
        mbfl_no_encoding_8bit,
        mbfl_no_encoding_base64,
        mbfl_filt_conv_common_ctor,
        mbfl_filt_conv_common_dtor,
        mbfl_filt_conv_base64enc,
        mbfl_filt_conv_base64enc_flush
};

const struct mbfl_convert_vtbl vtbl_b64_8bit = {
        mbfl_no_encoding_base64,
        mbfl_no_encoding_8bit,
        mbfl_filt_conv_common_ctor,
        mbfl_filt_conv_common_dtor,
        mbfl_filt_conv_base64dec,
        mbfl_filt_conv_base64dec_flush
};


#define CK(statement)   do { if ((statement) < 0) return (-1); } while (0)

/*
 * any => BASE64
 */
static const unsigned char mbfl_base64_table[] = {
 /* 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', */
   0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x4b,0x4c,0x4d,
 /* 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', */
   0x4e,0x4f,0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,
 /* 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', */
   0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,
 /* 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', */
   0x6e,0x6f,0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,
 /* '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/', '\0' */
   0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x2b,0x2f,0x00
};

int mbfl_filt_conv_base64enc(int c, mbfl_convert_filter *filter)
{
        int n;

        n = (filter->status & 0xff);
        if (n == 0) {
                filter->status++;
                filter->cache = (c & 0xff) << 16;
        } else if (n == 1) {
                filter->status++;
                filter->cache |= (c & 0xff) << 8;
        } else {
                filter->status &= ~0xff;
                if ((filter->status & MBFL_BASE64_STS_MIME_HEADER) == 0) {
                        n = (filter->status & 0xff00) >> 8;
                        if (n > 72) {
                                CK((*filter->output_function)(0x0d, filter->data));             /* CR */
                                CK((*filter->output_function)(0x0a, filter->data));             /* LF */
                                filter->status &= ~0xff00;
                        }
                        filter->status += 0x400;
                }
                n = filter->cache | (c & 0xff);
                CK((*filter->output_function)(mbfl_base64_table[(n >> 18) & 0x3f], filter->data));
                CK((*filter->output_function)(mbfl_base64_table[(n >> 12) & 0x3f], filter->data));
                CK((*filter->output_function)(mbfl_base64_table[(n >> 6) & 0x3f], filter->data));
                CK((*filter->output_function)(mbfl_base64_table[n & 0x3f], filter->data));
        }

        return c;
}

int mbfl_filt_conv_base64enc_flush(mbfl_convert_filter *filter)
{
        int status, cache, len;

        status = filter->status & 0xff;
        cache = filter->cache;
        len = (filter->status & 0xff00) >> 8;
        filter->status &= ~0xffff;
        filter->cache = 0;
        /* flush fragments */
        if (status >= 1) {
                if ((filter->status & MBFL_BASE64_STS_MIME_HEADER) == 0) {
                        if (len > 72){
                                CK((*filter->output_function)(0x0d, filter->data));             /* CR */
                                CK((*filter->output_function)(0x0a, filter->data));             /* LF */
                        }
                }
                CK((*filter->output_function)(mbfl_base64_table[(cache >> 18) & 0x3f], filter->data));
                CK((*filter->output_function)(mbfl_base64_table[(cache >> 12) & 0x3f], filter->data));
                if (status == 1) {
                        CK((*filter->output_function)(0x3d, filter->data));             /* '=' */
                        CK((*filter->output_function)(0x3d, filter->data));             /* '=' */
                } else {
                        CK((*filter->output_function)(mbfl_base64_table[(cache >> 6) & 0x3f], filter->data));
                        CK((*filter->output_function)(0x3d, filter->data));             /* '=' */
                }
        }
        return 0;
}

/*
 * BASE64 => any
 */
int mbfl_filt_conv_base64dec(int c, mbfl_convert_filter *filter)
{
        int n;

        if (c == 0x0d || c == 0x0a || c == 0x20 || c == 0x09 || c == 0x3d) {    /* CR or LF or SPACE or HTAB or '=' */
                return c;
        }

        n = 0;
        if (c >= 0x41 && c <= 0x5a) {           /* A - Z */
                n = c - 65;
        } else if (c >= 0x61 && c <= 0x7a) {    /* a - z */
                n = c - 71;
        } else if (c >= 0x30 && c <= 0x39) {    /* 0 - 9 */
                n = c + 4;
        } else if (c == 0x2b) {                 /* '+' */
                n = 62;
        } else if (c == 0x2f) {                 /* '/' */
                n = 63;
        }
        n &= 0x3f;

        switch (filter->status) {
        case 0:
                filter->status = 1;
                filter->cache = n << 18;
                break;
        case 1:
                filter->status = 2;
                filter->cache |= n << 12;
                break;
        case 2:
                filter->status = 3;
                filter->cache |= n << 6;
                break;
        default:
                filter->status = 0;
                n |= filter->cache;
                CK((*filter->output_function)((n >> 16) & 0xff, filter->data));
                CK((*filter->output_function)((n >> 8) & 0xff, filter->data));
                CK((*filter->output_function)(n & 0xff, filter->data));
                break;
        }

        return c;
}

int mbfl_filt_conv_base64dec_flush(mbfl_convert_filter *filter)
{
        int status, cache;

        status = filter->status;
        cache = filter->cache;
        filter->status = 0;
        filter->cache = 0;
        /* flush fragments */
        if (status >= 2) {
                CK((*filter->output_function)((cache >> 16) & 0xff, filter->data));
                if (status >= 3) {
                        CK((*filter->output_function)((cache >> 8) & 0xff, filter->data));
                }
        }
        return 0;
}



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