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 static gboolean get_hex_value(guchar *out, gchar c1, gchar c2);
  24 static void get_hex_str(gchar *out, guchar ch);
  25
  26 #define MAX_LINELEN     76
  27
  28 #define IS_LBREAK(p) \
  29         (*(p) == '\0' || *(p) == '\n' || (*(p) == '\r' && *((p) + 1) == '\n'))
  30
  31 #define SOFT_LBREAK_IF_REQUIRED(n)                                      \
  32         if (len + (n) > MAX_LINELEN ||                                  \
  33             (len + (n) == MAX_LINELEN && (!IS_LBREAK(inp + 1)))) {      \
  34                 *outp++ = '=';                                          \
  35                 *outp++ = '\n';                                         \
  36                 len = 0;                                                \
  37         }
  38
  39 void qp_encode_line(gchar *out, const guchar *in)
  40 {
  41         const guchar *inp = in;
  42         gchar *outp = out;
  43         guchar ch;
  44         gint len = 0;
  45
  46         while (*inp != '\0') {
  47                 ch = *inp;
  48
  49                 if (IS_LBREAK(inp)) {
  50                         *outp++ = '\n';
  51                         len = 0;
  52                         if (*inp == '\r')
  53                                 inp++;
  54                         inp++;
  55                 } else if (ch == '\t' || ch == ' ') {
  56                         if (IS_LBREAK(inp + 1)) {
  57                                 SOFT_LBREAK_IF_REQUIRED(3);
  58                                 *outp++ = '=';
  59                                 get_hex_str(outp, ch);
  60                                 outp += 2;
  61                                 len += 3;
  62                                 inp++;
  63                         } else {
  64                                 SOFT_LBREAK_IF_REQUIRED(1);
  65                                 *outp++ = *inp++;
  66                                 len++;
  67                         }
  68                 } else if ((ch >= 33 && ch <= 60) || (ch >= 62 && ch <= 126)) {
  69                         SOFT_LBREAK_IF_REQUIRED(1);
  70                         *outp++ = *inp++;
  71                         len++;
  72                 } else {
  73                         SOFT_LBREAK_IF_REQUIRED(3);
  74                         *outp++ = '=';
  75                         get_hex_str(outp, ch);
  76                         outp += 2;
  77                         len += 3;
  78                         inp++;
  79                 }
  80         }
  81
  82         if (len > 0)
  83                 *outp++ = '\n';
  84
  85         *outp = '\0';
  86 }
  87
  88 gint qp_decode_line(gchar *str)
  89 {
  90         gchar *inp = str, *outp = str;
  91
  92         while (*inp != '\0') {
  93                 if (*inp == '=') {
  94                         if (inp[1] && inp[2] &&
  95                             get_hex_value(outp, inp[1], inp[2]) == TRUE) {
  96                                 inp += 3;
  97                         } else if (inp[1] == '\0' || isspace((guchar)inp[1])) {
  98                                 /* soft line break */
  99                                 break;
 100                         } else {
 101                                 /* broken QP string */
 102                                 *outp = *inp++;
 103                         }
 104                 } else {
 105                         *outp = *inp++;
 106                 }
 107                 outp++;
 108         }
 109
 110         *outp = '\0';
 111
 112         return outp - str;
 113 }
 114
 115 gint qp_decode_q_encoding(guchar *out, const gchar *in, gint inlen)
 116 {
 117         const gchar *inp = in;
 118         guchar *outp = out;
 119
 120         if (inlen < 0)
 121                 inlen = G_MAXINT;
 122
 123         while (inp - in < inlen && *inp != '\0') {
 124                 if (*inp == '=' && inp + 3 - in <= inlen) {
 125                         if (get_hex_value(outp, inp[1], inp[2]) == TRUE) {
 126                                 inp += 3;
 127                         } else {
 128                                 *outp = *inp++;
 129                         }
 130                 } else if (*inp == '_') {
 131                         *outp = ' ';
 132                         inp++;
 133                 } else {
 134                         *outp = *inp++;
 135                 }
 136                 outp++;
 137         }
 138
 139         *outp = '\0';
 140
 141         return outp - out;
 142 }
 143
 144 gint qp_get_q_encoding_len(const guchar *str)
 145 {
 146         const guchar *inp = str;
 147         gint len = 0;
 148
 149         while (*inp != '\0') {
 150                 if (*inp == 0x20)
 151                         len++;
 152                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
 153                          *inp < 32 || *inp > 127 || isspace(*inp))
 154                         len += 3;
 155                 else
 156                         len++;
 157
 158                 inp++;
 159         }
 160
 161         return len;
 162 }
 163
 164 void qp_q_encode(gchar *out, const guchar *in)
 165 {
 166         const guchar *inp = in;
 167         gchar *outp = out;
 168
 169         while (*inp != '\0') {
 170                 if (*inp == 0x20)
 171                         *outp++ = '_';
 172                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
 173                          *inp < 32 || *inp > 127 || isspace(*inp)) {
 174                         *outp++ = '=';
 175                         get_hex_str(outp, *inp);
 176                         outp += 2;
 177                 } else
 178                         *outp++ = *inp;
 179
 180                 inp++;
 181         }
 182
 183         *outp = '\0';
 184 }
 185
 186 #define HEX_TO_INT(val, hex)                    \
 187 {                                               \
 188         gchar c = hex;                          \
 189                                                 \
 190         if ('0' <= c && c <= '9') {             \
 191                 val = c - '0';                  \
 192         } else if ('a' <= c && c <= 'f') {      \
 193                 val = c - 'a' + 10;             \
 194         } else if ('A' <= c && c <= 'F') {      \
 195                 val = c - 'A' + 10;             \
 196         } else {                                \
 197                 val = -1;                       \
 198         }                                       \
 199 }
 200
 201 static gboolean get_hex_value(guchar *out, gchar c1, gchar c2)
 202 {
 203         gint hi, lo;
 204
 205         HEX_TO_INT(hi, c1);
 206         HEX_TO_INT(lo, c2);
 207
 208         if (hi == -1 || lo == -1)
 209                 return FALSE;
 210
 211         *out = (hi << 4) + lo;
 212         return TRUE;
 213 }
 214
 215 #define INT_TO_HEX(hex, val)            \
 216 {                                       \
 217         if ((val) < 10)                 \
 218                 hex = '0' + (val);      \
 219         else                            \
 220                 hex = 'A' + (val) - 10; \
 221 }
 222
 223 static void get_hex_str(gchar *out, guchar ch)
 224 {
 225         gchar hex;
 226
 227         INT_TO_HEX(hex, ch >> 4);
 228         *out++ = hex;
 229         INT_TO_HEX(hex, ch & 0x0f);
 230         *out++ = hex;
 231 }