d9898ee8 |
1 | /* |
2 | ** Copyright 2003-2004 Double Precision, Inc. See COPYING for |
3 | ** distribution information. |
4 | */ |
5 | |
6 | /* |
d9898ee8 |
7 | */ |
8 | #include "encode.h" |
9 | #include <string.h> |
10 | #include <stdlib.h> |
11 | |
12 | static int quoted_printable(struct libmail_encode_info *, |
13 | const char *, size_t); |
14 | static int base64(struct libmail_encode_info *, |
15 | const char *, size_t); |
16 | static int eflush(struct libmail_encode_info *, |
17 | const char *, size_t); |
18 | |
19 | void libmail_encode_start(struct libmail_encode_info *info, |
20 | const char *transfer_encoding, |
21 | int (*callback_func)(const char *, size_t, void *), |
22 | void *callback_arg) |
23 | { |
24 | info->output_buf_cnt=0; |
25 | info->input_buf_cnt=0; |
26 | |
27 | switch (*transfer_encoding) { |
28 | case 'q': |
29 | case 'Q': |
30 | info->encoding_func=quoted_printable; |
31 | info->input_buffer[0]=0; /* Recycle for qp encoding */ |
32 | break; |
33 | case 'b': |
34 | case 'B': |
35 | info->encoding_func=base64; |
36 | break; |
37 | default: |
38 | info->encoding_func=eflush; |
39 | break; |
40 | } |
41 | info->callback_func=callback_func; |
42 | info->callback_arg=callback_arg; |
43 | } |
44 | |
45 | int libmail_encode(struct libmail_encode_info *info, |
46 | const char *ptr, |
47 | size_t cnt) |
48 | { |
49 | return ((*info->encoding_func)(info, ptr, cnt)); |
50 | } |
51 | |
52 | int libmail_encode_end(struct libmail_encode_info *info) |
53 | { |
54 | int rc=(*info->encoding_func)(info, NULL, 0); |
55 | |
56 | if (rc == 0 && info->output_buf_cnt > 0) |
57 | { |
58 | rc= (*info->callback_func)(info->output_buffer, |
59 | info->output_buf_cnt, |
60 | info->callback_arg); |
61 | info->output_buf_cnt=0; |
62 | } |
63 | |
64 | return rc; |
65 | } |
66 | |
67 | static int eflush(struct libmail_encode_info *info, const char *ptr, size_t n) |
68 | { |
69 | while (n > 0) |
70 | { |
71 | size_t i; |
72 | |
73 | if (info->output_buf_cnt == sizeof(info->output_buffer)) |
74 | { |
75 | int rc= (*info->callback_func)(info->output_buffer, |
76 | info->output_buf_cnt, |
77 | info->callback_arg); |
78 | |
79 | info->output_buf_cnt=0; |
80 | if (rc) |
81 | return rc; |
82 | } |
83 | |
84 | i=n; |
85 | |
86 | if (i > sizeof(info->output_buffer) - info->output_buf_cnt) |
87 | i=sizeof(info->output_buffer) - info->output_buf_cnt; |
88 | |
89 | memcpy(info->output_buffer + info->output_buf_cnt, ptr, i); |
90 | info->output_buf_cnt += i; |
91 | ptr += i; |
92 | n -= i; |
93 | } |
94 | return 0; |
95 | } |
96 | |
97 | static int base64_flush(struct libmail_encode_info *); |
98 | |
99 | static int base64(struct libmail_encode_info *info, |
100 | const char *buf, size_t n) |
101 | { |
102 | if (!buf) |
103 | { |
104 | int rc=0; |
105 | |
106 | if (info->input_buf_cnt > 0) |
107 | rc=base64_flush(info); |
108 | |
109 | return rc; |
110 | } |
111 | |
112 | while (n) |
113 | { |
114 | size_t i; |
115 | |
116 | if (info->input_buf_cnt == sizeof(info->input_buffer)) |
117 | { |
118 | int rc=base64_flush(info); |
119 | |
120 | if (rc != 0) |
121 | return rc; |
122 | } |
123 | |
124 | i=n; |
125 | if (i > sizeof(info->input_buffer) - info->input_buf_cnt) |
126 | i=sizeof(info->input_buffer) - info->input_buf_cnt; |
127 | |
128 | memcpy(info->input_buffer + info->input_buf_cnt, |
129 | buf, i); |
130 | info->input_buf_cnt += i; |
131 | buf += i; |
132 | n -= i; |
133 | } |
134 | return 0; |
135 | } |
136 | |
137 | static const char base64tab[]= |
138 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
139 | |
140 | static int base64_flush(struct libmail_encode_info *info) |
141 | { |
142 | int a=0,b=0,c=0; |
143 | int i, j; |
144 | int d, e, f, g; |
145 | char output_buf[ sizeof(info->input_buffer) / 3 * 4+1]; |
146 | |
147 | for (j=i=0; i<info->input_buf_cnt; i += 3) |
148 | { |
149 | a=(unsigned char)info->input_buffer[i]; |
150 | b= i+1 < info->input_buf_cnt ? |
151 | (unsigned char)info->input_buffer[i+1]:0; |
152 | c= i+2 < info->input_buf_cnt ? |
153 | (unsigned char)info->input_buffer[i+2]:0; |
154 | |
155 | d=base64tab[ a >> 2 ]; |
156 | e=base64tab[ ((a & 3 ) << 4) | (b >> 4)]; |
157 | f=base64tab[ ((b & 15) << 2) | (c >> 6)]; |
158 | g=base64tab[ c & 63 ]; |
159 | if (i + 1 >= info->input_buf_cnt) f='='; |
160 | if (i + 2 >= info->input_buf_cnt) g='='; |
161 | output_buf[j++]=d; |
162 | output_buf[j++]=e; |
163 | output_buf[j++]=f; |
164 | output_buf[j++]=g; |
165 | } |
166 | |
167 | info->input_buf_cnt=0; |
168 | |
169 | output_buf[j++]='\n'; |
170 | return eflush(info, output_buf, j); |
171 | } |
172 | |
173 | static const char xdigit[]="0123456789ABCDEF"; |
174 | |
175 | static int quoted_printable(struct libmail_encode_info *info, |
176 | const char *p, size_t n) |
177 | { |
178 | char local_buf[256]; |
179 | int local_buf_cnt=0; |
180 | |
181 | #define QPUT(c) do { if (local_buf_cnt == sizeof(local_buf)) \ |
182 | { int rc=eflush(info, local_buf, local_buf_cnt); \ |
183 | local_buf_cnt=0; if (rc) return (rc); } \ |
184 | local_buf[local_buf_cnt]=(c); ++local_buf_cnt; } while(0) |
185 | |
186 | if (!p) |
187 | return (0); |
188 | |
189 | while (n) |
190 | { |
191 | |
192 | |
193 | /* |
194 | ** Repurpose input_buffer[0] as a flag whether the previous |
195 | ** character was a space. |
196 | ** |
197 | ** A space before a newline gets escaped. |
198 | */ |
199 | |
200 | if (info->input_buffer[0]) |
201 | { |
202 | if (*p == '\n') |
203 | { |
204 | QPUT('='); |
205 | QPUT('2'); |
206 | QPUT('0'); |
207 | } |
208 | else |
209 | { |
210 | QPUT(' '); |
211 | } |
212 | ++info->input_buf_cnt; |
213 | } |
214 | |
215 | info->input_buffer[0]=0; |
216 | |
217 | if (*p == ' ') |
218 | { |
219 | info->input_buffer[0]=1; |
220 | p++; |
221 | --n; |
222 | continue; |
223 | } |
224 | |
225 | if (info->input_buf_cnt > 72 && *p != '\n') |
226 | { |
227 | QPUT('='); |
228 | QPUT('\n'); |
229 | info->input_buf_cnt=0; |
230 | } |
231 | |
232 | if ( *p == '\n') |
233 | info->input_buf_cnt=0; |
234 | else if (*p < ' ' || *p == '=' || *p >= 0x7F) |
235 | { |
236 | QPUT('='); |
237 | QPUT(xdigit[ (*p >> 4) & 15]); |
238 | QPUT(xdigit[ *p & 15 ]); |
239 | info->input_buf_cnt += 3; |
240 | p++; |
241 | --n; |
242 | continue; |
243 | } |
244 | else info->input_buf_cnt++; |
245 | |
246 | QPUT( *p); |
247 | p++; |
248 | --n; |
249 | } |
250 | |
251 | if (local_buf_cnt > 0) |
252 | return eflush(info, local_buf, local_buf_cnt); |
253 | |
254 | return 0; |
255 | } |