2007-01-05 [colin] 2.6.1cvs108
[claws.git] / src / common / quoted-printable.c
1 /*
2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
3  * Copyright (C) 1999-2007 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 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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] && inp[1] == '0' && inp[2] == '0') {
94                                 inp += 3;
95                                 continue;
96                         } else if (inp[1] && inp[2] &&
97                             get_hex_value((guchar *)outp, inp[1], inp[2])
98                             == TRUE) {
99                                 inp += 3;
100                         } else if (inp[1] == '\0' || g_ascii_isspace(inp[1])) {
101                                 /* soft line break */
102                                 break;
103                         } else {
104                                 /* broken QP string */
105                                 *outp = *inp++;
106                         }
107                 } else {
108                         *outp = *inp++;
109                 }
110                 outp++;
111         }
112
113         *outp = '\0';
114
115         return outp - str;
116 }
117
118 gint qp_decode_const(gchar *out, gint avail, const gchar *str)
119 {
120         const gchar *inp = str;
121         gchar *outp = out;
122
123         while (*inp != '\0' && avail > 0) {
124                 if (*inp == '=') {
125                         if (inp[1] && inp[2] && inp[1] == '0' && inp[2] == '0') {
126                                 inp += 3;
127                                 continue;
128                         } else if (inp[1] && inp[2] &&
129                             get_hex_value((guchar *)outp, inp[1], inp[2])
130                             == TRUE) {
131                                 inp += 3;
132                         } else if (inp[1] == '\0' || g_ascii_isspace(inp[1])) {
133                                 /* soft line break */
134                                 break;
135                         } else {
136                                 /* broken QP string */
137                                 *outp = *inp++;
138                         }
139                 } else {
140                         *outp = *inp++;
141                 }
142                 outp++;
143                 avail--;
144         }
145
146         *outp = '\0';
147
148         return outp - out;
149 }
150
151 gint qp_decode_q_encoding(guchar *out, const gchar *in, gint inlen)
152 {
153         const gchar *inp = in;
154         guchar *outp = out;
155
156         if (inlen < 0)
157                 inlen = G_MAXINT;
158
159         while (inp - in < inlen && *inp != '\0') {
160                 if (*inp == '=' && inp + 3 - in <= inlen) {
161                         if (inp[1] && inp[2] && inp[1] == '0' && inp[2] == '0') {
162                                 inp += 3;
163                                 continue;
164                         } else if (get_hex_value(outp, inp[1], inp[2]) == TRUE) {
165                                 inp += 3;
166                         } else {
167                                 *outp = *inp++;
168                         }
169                 } else if (*inp == '_') {
170                         *outp = ' ';
171                         inp++;
172                 } else {
173                         *outp = *inp++;
174                 }
175                 outp++;
176         }
177
178         *outp = '\0';
179
180         return outp - out;
181 }
182
183 gint qp_get_q_encoding_len(const guchar *str)
184 {
185         const guchar *inp = str;
186         gint len = 0;
187
188         while (*inp != '\0') {
189                 if (*inp == 0x20)
190                         len++;
191                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
192                          *inp < 32 || *inp > 127 || g_ascii_isspace(*inp))
193                         len += 3;
194                 else
195                         len++;
196
197                 inp++;
198         }
199
200         return len;
201 }
202
203 void qp_q_encode(gchar *out, const guchar *in)
204 {
205         const guchar *inp = in;
206         gchar *outp = out;
207
208         while (*inp != '\0') {
209                 if (*inp == 0x20)
210                         *outp++ = '_';
211                 else if (*inp == '=' || *inp == '?' || *inp == '_' ||
212                          *inp < 32 || *inp > 127 || g_ascii_isspace(*inp)) {
213                         *outp++ = '=';
214                         get_hex_str(outp, *inp);
215                         outp += 2;
216                 } else
217                         *outp++ = *inp;
218
219                 inp++;
220         }
221
222         *outp = '\0';
223 }