src/common/uuencode.c

   1 /*
   2  * Claws Mail -- a GTK based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2024 Hiroyuki Yamamoto and the Claws Mail Team
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "config.h"
  20
  21 #include <ctype.h>
  22
  23 #define UUDECODE(c) (c=='`' ? 0 : c - ' ')
  24 #define N64(i) (i & ~63)
  25
  26 const char uudigit[64] =
  27 {
  28   '`', '!', '"', '#', '$', '%', '&', '\'',
  29   '(', ')', '*', '+', ',', '-', '.', '/',
  30   '0', '1', '2', '3', '4', '5', '6', '7',
  31   '8', '9', ':', ';', '<', '=', '>', '?',
  32   '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
  33   'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
  34   'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
  35   'X', 'Y', 'Z', '[', '\\', ']', '^', '_'
  36 };
  37
  38 int fromuutobits(char *out, const char *in)
  39 {
  40     int len, outlen, inlen;
  41     register unsigned char digit1, digit2;
  42
  43     outlen = UUDECODE(in[0]);
  44     in += 1;
  45     if(outlen < 0 || outlen > 45)
  46         return -2;
  47     if(outlen == 0)
  48         return 0;
  49     inlen = (outlen * 4 + 2) / 3;
  50     len = 0;
  51
  52     for( ; inlen>0; inlen-=4) {
  53         digit1 = UUDECODE(in[0]);
  54         if (N64(digit1)) return -1;
  55         digit2 = UUDECODE(in[1]);
  56         if (N64(digit2)) return -1;
  57         out[len++] = (digit1 << 2) | (digit2 >> 4);
  58         if (inlen > 2) {
  59             digit1 = UUDECODE(in[2]);
  60             if (N64(digit1)) return -1;
  61             out[len++] = (digit2 << 4) | (digit1 >> 2);
  62             if (inlen > 3) {
  63                 digit2 = UUDECODE(in[3]);
  64                 if (N64(digit2)) return -1;
  65                 out[len++] = (digit1 << 6) | digit2;
  66             }
  67         }
  68         in += 4;
  69     }
  70
  71     return len == outlen ? len : -3;
  72 }