src/common/quoted-printable.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2003 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 #include "utils.h"
  24
  25 #define MAX_LINELEN     76
  26
  27 #define IS_LBREAK(p) \
  28         (*(p) == '\0' || *(p) == '\n' || (*(p) == '\r' && *((p) + 1) == '\n'))
  29
  30 #define SOFT_LBREAK_IF_REQUIRED(n)                                      \
  31         if (len + (n) > MAX_LINELEN ||                                  \
  32             (len + (n) == MAX_LINELEN && (!IS_LBREAK(inp + 1)))) {      \
  33                 *outp++ = '=';                                          \
  34                 *outp++ = '\n';                                         \
  35                 len = 0;                                                \
  36         }
  37
  38 void qp_encode_line(gchar *out, const guchar *in)
  39 {
  40         const guchar *inp = in;
  41         gchar *outp = out;
  42         guchar ch;
  43         gint len = 0;
  44
  45         while (*inp != '\0') {
  46                 ch = *inp;
  47
  48                 if (IS_LBREAK(inp)) {
  49                         *outp++ = '\n';
  50                         len = 0;
  51                         if (*inp == '\r')
  52                                 inp++;
  53                         inp++;
  54                 } else if (ch == '\t' || ch == ' ') {
  55                         if (IS_LBREAK(inp + 1)) {
  56                                 SOFT_LBREAK_IF_REQUIRED(3);
  57                                 *outp++ = '=';
  58                                 get_hex_str(outp, ch);
  59                                 outp += 2;
  60                                 len += 3;
  61                                 inp++;
  62                         } else {
  63                                 SOFT_LBREAK_IF_REQUIRED(1);
  64                                 *outp++ = *inp++;
  65                                 len++;
  66                         }
  67                 } else if ((ch >= 33 && ch <= 60) || (ch >= 62 && ch <= 126)) {
  68                         SOFT_LBREAK_IF_REQUIRED(1);
  69                         *outp++ = *inp++;
  70                         len++;
  71                 } else {
  72                         SOFT_LBREAK_IF_REQUIRED(3);
  73                         *outp++ = '=';
  74                         get_hex_str(outp, ch);
  75                         outp += 2;
  76                         len += 3;
  77                         inp++;
  78                 }
  79         }
  80
  81         if (len > 0)
  82                 *outp++ = '\n';
  83
  84         *outp = '\0';
  85 }
  86
  87 gint qp_decode_line(gchar *str)
  88 {
  89         gchar *inp = str, *outp = str;
  90
  91         while (*inp != '\0') {
  92                 if (*inp == '=') {
  93                         if (inp[1] && inp[2] &&
  94                             get_hex_value(outp, inp[1], inp[2]) == TRUE) {
  95                                 inp += 3;
  96                         } else if (inp[1] == '\0' || isspace((guchar)inp[1])) {
  97                                 /* soft line break */
  98                                 break;
  99                         } else {
 100                                 /* broken QP string */
 101                                 *outp = *inp++;
 102                         }
 103                 } else {
 104                         *outp = *inp++;
 105                 }
 106                 outp++;
 107         }
 108
 109         *outp = '\0';
 110
 111         return outp - str;
 112 }
 113
 114 gint qp_decode_q_encoding(guchar *out, const gchar *in, gint inlen)
 115 {
 116         const gchar *inp = in;
 117         guchar *outp = out;
 118
 119         if (inlen < 0)
 120                 inlen = G_MAXINT;
 121
 122         while (inp - in < inlen && *inp != '\0') {
 123                 if (*inp == '=' && inp + 3 - in <= inlen) {
 124                         if (get_hex_value(outp, inp[1], inp[2]) == TRUE) {
 125                                 inp += 3;
 126                         } else {
 127                                 *outp = *inp++;
 128                         }
 129                 } else if (*inp == '_') {
 130                         *outp = ' ';
 131                         inp++;
 132                 } else {
 133                         *outp = *inp++;
 134                 }
 135                 outp++;
 136         }
 137
 138         *outp = '\0';
 139
 140         return outp - out;
 141 }
 142
 143 gint qp_get_q_encoding_len(const guchar *str)
 144 {
 145         const guchar *inp = str;
 146         gint len = 0;
 147
 148         while (*inp != '\0') {
 149                 if (*inp == 0x20)
 150                         len++;
 151                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
 152                          *inp < 32 || *inp > 127 || isspace(*inp))
 153                         len += 3;
 154                 else
 155                         len++;
 156
 157                 inp++;
 158         }
 159
 160         return len;
 161 }
 162
 163 void qp_q_encode(gchar *out, const guchar *in)
 164 {
 165         const guchar *inp = in;
 166         gchar *outp = out;
 167
 168         while (*inp != '\0') {
 169                 if (*inp == 0x20)
 170                         *outp++ = '_';
 171                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
 172                          *inp < 32 || *inp > 127 || isspace(*inp)) {
 173                         *outp++ = '=';
 174                         get_hex_str(outp, *inp);
 175                         outp += 2;
 176                 } else
 177                         *outp++ = *inp;
 178
 179                 inp++;
 180         }
 181
 182         *outp = '\0';
 183 }