d9898ee8 |
1 | /* |
2 | ** Copyright 2003-2004 Double Precision, Inc. See COPYING for |
3 | ** distribution information. |
4 | */ |
5 | |
6 | /* |
7 | ** $Id: encode.c,v 1.5 2005/11/16 02:23:15 mrsam Exp $ |
8 | */ |
9 | #include "encode.h" |
10 | #include <string.h> |
11 | #include <stdlib.h> |
12 | |
13 | static int quoted_printable(struct libmail_encode_info *, |
14 | const char *, size_t); |
15 | static int base64(struct libmail_encode_info *, |
16 | const char *, size_t); |
17 | static int eflush(struct libmail_encode_info *, |
18 | const char *, size_t); |
19 | |
20 | void libmail_encode_start(struct libmail_encode_info *info, |
21 | const char *transfer_encoding, |
22 | int (*callback_func)(const char *, size_t, void *), |
23 | void *callback_arg) |
24 | { |
25 | info->output_buf_cnt=0; |
26 | info->input_buf_cnt=0; |
27 | |
28 | switch (*transfer_encoding) { |
29 | case 'q': |
30 | case 'Q': |
31 | info->encoding_func=quoted_printable; |
32 | info->input_buffer[0]=0; /* Recycle for qp encoding */ |
33 | break; |
34 | case 'b': |
35 | case 'B': |
36 | info->encoding_func=base64; |
37 | break; |
38 | default: |
39 | info->encoding_func=eflush; |
40 | break; |
41 | } |
42 | info->callback_func=callback_func; |
43 | info->callback_arg=callback_arg; |
44 | } |
45 | |
46 | int libmail_encode(struct libmail_encode_info *info, |
47 | const char *ptr, |
48 | size_t cnt) |
49 | { |
50 | return ((*info->encoding_func)(info, ptr, cnt)); |
51 | } |
52 | |
53 | int libmail_encode_end(struct libmail_encode_info *info) |
54 | { |
55 | int rc=(*info->encoding_func)(info, NULL, 0); |
56 | |
57 | if (rc == 0 && info->output_buf_cnt > 0) |
58 | { |
59 | rc= (*info->callback_func)(info->output_buffer, |
60 | info->output_buf_cnt, |
61 | info->callback_arg); |
62 | info->output_buf_cnt=0; |
63 | } |
64 | |
65 | return rc; |
66 | } |
67 | |
68 | static int eflush(struct libmail_encode_info *info, const char *ptr, size_t n) |
69 | { |
70 | while (n > 0) |
71 | { |
72 | size_t i; |
73 | |
74 | if (info->output_buf_cnt == sizeof(info->output_buffer)) |
75 | { |
76 | int rc= (*info->callback_func)(info->output_buffer, |
77 | info->output_buf_cnt, |
78 | info->callback_arg); |
79 | |
80 | info->output_buf_cnt=0; |
81 | if (rc) |
82 | return rc; |
83 | } |
84 | |
85 | i=n; |
86 | |
87 | if (i > sizeof(info->output_buffer) - info->output_buf_cnt) |
88 | i=sizeof(info->output_buffer) - info->output_buf_cnt; |
89 | |
90 | memcpy(info->output_buffer + info->output_buf_cnt, ptr, i); |
91 | info->output_buf_cnt += i; |
92 | ptr += i; |
93 | n -= i; |
94 | } |
95 | return 0; |
96 | } |
97 | |
98 | static int base64_flush(struct libmail_encode_info *); |
99 | |
100 | static int base64(struct libmail_encode_info *info, |
101 | const char *buf, size_t n) |
102 | { |
103 | if (!buf) |
104 | { |
105 | int rc=0; |
106 | |
107 | if (info->input_buf_cnt > 0) |
108 | rc=base64_flush(info); |
109 | |
110 | return rc; |
111 | } |
112 | |
113 | while (n) |
114 | { |
115 | size_t i; |
116 | |
117 | if (info->input_buf_cnt == sizeof(info->input_buffer)) |
118 | { |
119 | int rc=base64_flush(info); |
120 | |
121 | if (rc != 0) |
122 | return rc; |
123 | } |
124 | |
125 | i=n; |
126 | if (i > sizeof(info->input_buffer) - info->input_buf_cnt) |
127 | i=sizeof(info->input_buffer) - info->input_buf_cnt; |
128 | |
129 | memcpy(info->input_buffer + info->input_buf_cnt, |
130 | buf, i); |
131 | info->input_buf_cnt += i; |
132 | buf += i; |
133 | n -= i; |
134 | } |
135 | return 0; |
136 | } |
137 | |
138 | static const char base64tab[]= |
139 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
140 | |
141 | static int base64_flush(struct libmail_encode_info *info) |
142 | { |
143 | int a=0,b=0,c=0; |
144 | int i, j; |
145 | int d, e, f, g; |
146 | char output_buf[ sizeof(info->input_buffer) / 3 * 4+1]; |
147 | |
148 | for (j=i=0; i<info->input_buf_cnt; i += 3) |
149 | { |
150 | a=(unsigned char)info->input_buffer[i]; |
151 | b= i+1 < info->input_buf_cnt ? |
152 | (unsigned char)info->input_buffer[i+1]:0; |
153 | c= i+2 < info->input_buf_cnt ? |
154 | (unsigned char)info->input_buffer[i+2]:0; |
155 | |
156 | d=base64tab[ a >> 2 ]; |
157 | e=base64tab[ ((a & 3 ) << 4) | (b >> 4)]; |
158 | f=base64tab[ ((b & 15) << 2) | (c >> 6)]; |
159 | g=base64tab[ c & 63 ]; |
160 | if (i + 1 >= info->input_buf_cnt) f='='; |
161 | if (i + 2 >= info->input_buf_cnt) g='='; |
162 | output_buf[j++]=d; |
163 | output_buf[j++]=e; |
164 | output_buf[j++]=f; |
165 | output_buf[j++]=g; |
166 | } |
167 | |
168 | info->input_buf_cnt=0; |
169 | |
170 | output_buf[j++]='\n'; |
171 | return eflush(info, output_buf, j); |
172 | } |
173 | |
174 | static const char xdigit[]="0123456789ABCDEF"; |
175 | |
176 | static int quoted_printable(struct libmail_encode_info *info, |
177 | const char *p, size_t n) |
178 | { |
179 | char local_buf[256]; |
180 | int local_buf_cnt=0; |
181 | |
182 | #define QPUT(c) do { if (local_buf_cnt == sizeof(local_buf)) \ |
183 | { int rc=eflush(info, local_buf, local_buf_cnt); \ |
184 | local_buf_cnt=0; if (rc) return (rc); } \ |
185 | local_buf[local_buf_cnt]=(c); ++local_buf_cnt; } while(0) |
186 | |
187 | if (!p) |
188 | return (0); |
189 | |
190 | while (n) |
191 | { |
192 | |
193 | |
194 | /* |
195 | ** Repurpose input_buffer[0] as a flag whether the previous |
196 | ** character was a space. |
197 | ** |
198 | ** A space before a newline gets escaped. |
199 | */ |
200 | |
201 | if (info->input_buffer[0]) |
202 | { |
203 | if (*p == '\n') |
204 | { |
205 | QPUT('='); |
206 | QPUT('2'); |
207 | QPUT('0'); |
208 | } |
209 | else |
210 | { |
211 | QPUT(' '); |
212 | } |
213 | ++info->input_buf_cnt; |
214 | } |
215 | |
216 | info->input_buffer[0]=0; |
217 | |
218 | if (*p == ' ') |
219 | { |
220 | info->input_buffer[0]=1; |
221 | p++; |
222 | --n; |
223 | continue; |
224 | } |
225 | |
226 | if (info->input_buf_cnt > 72 && *p != '\n') |
227 | { |
228 | QPUT('='); |
229 | QPUT('\n'); |
230 | info->input_buf_cnt=0; |
231 | } |
232 | |
233 | if ( *p == '\n') |
234 | info->input_buf_cnt=0; |
235 | else if (*p < ' ' || *p == '=' || *p >= 0x7F) |
236 | { |
237 | QPUT('='); |
238 | QPUT(xdigit[ (*p >> 4) & 15]); |
239 | QPUT(xdigit[ *p & 15 ]); |
240 | info->input_buf_cnt += 3; |
241 | p++; |
242 | --n; |
243 | continue; |
244 | } |
245 | else info->input_buf_cnt++; |
246 | |
247 | QPUT( *p); |
248 | p++; |
249 | --n; |
250 | } |
251 | |
252 | if (local_buf_cnt > 0) |
253 | return eflush(info, local_buf, local_buf_cnt); |
254 | |
255 | return 0; |
256 | } |