src/common/quoted-printable.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2002 Hiroyuki Yamamoto
   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 2 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, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #include <glib.h>
  21 #include <ctype.h>
  22
  23 static gboolean get_hex_value(guchar *out, gchar c1, gchar c2);
  24 static void get_hex_str(gchar *out, guchar ch);
  25
  26 gint qp_decode_line(gchar *str)
  27 {
  28         gchar *inp = str, *outp = str;
  29
  30         while (*inp != '\0') {
  31                 if (*inp == '=') {
  32                         if (inp[1] && inp[2] &&
  33                             get_hex_value(outp, inp[1], inp[2]) == TRUE) {
  34                                 inp += 3;
  35                         } else if (inp[1] == '\0' || isspace(inp[1])) {
  36                                 /* soft line break */
  37                                 break;
  38                         } else {
  39                                 /* broken QP string */
  40                                 *outp = *inp++;
  41                         }
  42                 } else {
  43                         *outp = *inp++;
  44                 }
  45                 outp++;
  46         }
  47
  48         *outp = '\0';
  49
  50         return outp - str;
  51 }
  52
  53 gint qp_decode_q_encoding(guchar *out, const gchar *in, gint inlen)
  54 {
  55         const gchar *inp = in;
  56         guchar *outp = out;
  57
  58         if (inlen < 0)
  59                 inlen = G_MAXINT;
  60
  61         while (inp - in < inlen && *inp != '\0') {
  62                 if (*inp == '=' && inp + 3 - in <= inlen) {
  63                         if (get_hex_value(outp, inp[1], inp[2]) == TRUE) {
  64                                 inp += 3;
  65                         } else {
  66                                 *outp = *inp++;
  67                         }
  68                 } else if (*inp == '_') {
  69                         *outp = ' ';
  70                         inp++;
  71                 } else {
  72                         *outp = *inp++;
  73                 }
  74                 outp++;
  75         }
  76
  77         *outp = '\0';
  78
  79         return outp - out;
  80 }
  81
  82 gint qp_get_q_encoding_len(const guchar *str)
  83 {
  84         const guchar *inp = str;
  85         gint len = 0;
  86
  87         while (*inp != '\0') {
  88                 if (*inp == 0x20)
  89                         len++;
  90                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
  91                          *inp < 32 || *inp > 127 || isspace(*inp))
  92                         len += 3;
  93                 else
  94                         len++;
  95
  96                 inp++;
  97         }
  98
  99         return len;
 100 }
 101
 102 void qp_q_encode(gchar *out, const guchar *in)
 103 {
 104         const guchar *inp = in;
 105         gchar *outp = out;
 106
 107         while (*inp != '\0') {
 108                 if (*inp == 0x20)
 109                         *outp++ = '_';
 110                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
 111                          *inp < 32 || *inp > 127 || isspace(*inp)) {
 112                         *outp++ = '=';
 113                         get_hex_str(outp, *inp);
 114                         outp += 2;
 115                 } else
 116                         *outp++ = *inp;
 117
 118                 inp++;
 119         }
 120
 121         *outp = '\0';
 122 }
 123
 124 #define HEX_TO_INT(val, hex)                    \
 125 {                                               \
 126         gchar c = hex;                          \
 127                                                 \
 128         if ('0' <= c && c <= '9') {             \
 129                 val = c - '0';                  \
 130         } else if ('a' <= c && c <= 'f') {      \
 131                 val = c - 'a' + 10;             \
 132         } else if ('A' <= c && c <= 'F') {      \
 133                 val = c - 'A' + 10;             \
 134         } else {                                \
 135                 val = -1;                       \
 136         }                                       \
 137 }
 138
 139 static gboolean get_hex_value(guchar *out, gchar c1, gchar c2)
 140 {
 141         gint hi, lo;
 142
 143         HEX_TO_INT(hi, c1);
 144         HEX_TO_INT(lo, c2);
 145
 146         if (hi == -1 || lo == -1)
 147                 return FALSE;
 148
 149         *out = (hi << 4) + lo;
 150         return TRUE;
 151 }
 152
 153 #define INT_TO_HEX(hex, val)            \
 154 {                                       \
 155         if ((val) < 10)                 \
 156                 hex = '0' + (val);      \
 157         else                            \
 158                 hex = 'A' + (val) - 10; \
 159 }
 160
 161 static void get_hex_str(gchar *out, guchar ch)
 162 {
 163         gchar hex;
 164
 165         INT_TO_HEX(hex, ch >> 4);
 166         *out++ = hex;
 167         INT_TO_HEX(hex, ch & 0x0f);
 168         *out++ = hex;
 169 }