1
2 /*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8 #include <ngx_config.h>
9 #include <ngx_core.h>
10 #include <ngx_event.h>
11 #include <ngx_mail.h>
12 #include <ngx_mail_imap_module.h>
13
14
15 static ngx_int_t ngx_mail_imap_login(ngx_mail_session_t *s,
16 ngx_connection_t *c);
17 static ngx_int_t ngx_mail_imap_authenticate(ngx_mail_session_t *s,
18 ngx_connection_t *c);
19 static ngx_int_t ngx_mail_imap_capability(ngx_mail_session_t *s,
20 ngx_connection_t *c);
21 static ngx_int_t ngx_mail_imap_starttls(ngx_mail_session_t *s,
22 ngx_connection_t *c);
23
24
25 static u_char imap_greeting[] = "* OK IMAP4 ready" CRLF;
26 static u_char imap_star[] = "* ";
27 static u_char imap_ok[] = "OK completed" CRLF;
28 static u_char imap_next[] = "+ OK" CRLF;
29 static u_char imap_plain_next[] = "+ " CRLF;
30 static u_char imap_username[] = "+ VXNlcm5hbWU6" CRLF;
31 static u_char imap_password[] = "+ UGFzc3dvcmQ6" CRLF;
32 static u_char imap_bye[] = "* BYE" CRLF;
33 static u_char imap_invalid_command[] = "BAD invalid command" CRLF;
34
35
36 void
ngx_mail_imap_init_session(ngx_mail_session_t * s,ngx_connection_t * c)37 ngx_mail_imap_init_session(ngx_mail_session_t *s, ngx_connection_t *c)
38 {
39 ngx_mail_core_srv_conf_t *cscf;
40
41 cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
42
43 ngx_str_set(&s->out, imap_greeting);
44
45 c->read->handler = ngx_mail_imap_init_protocol;
46
47 ngx_add_timer(c->read, cscf->timeout);
48
49 if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
50 ngx_mail_close_connection(c);
51 }
52
53 ngx_mail_send(c->write);
54 }
55
56
57 void
ngx_mail_imap_init_protocol(ngx_event_t * rev)58 ngx_mail_imap_init_protocol(ngx_event_t *rev)
59 {
60 ngx_connection_t *c;
61 ngx_mail_session_t *s;
62 ngx_mail_imap_srv_conf_t *iscf;
63
64 c = rev->data;
65
66 c->log->action = "in auth state";
67
68 if (rev->timedout) {
69 ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
70 c->timedout = 1;
71 ngx_mail_close_connection(c);
72 return;
73 }
74
75 s = c->data;
76
77 if (s->buffer == NULL) {
78 if (ngx_array_init(&s->args, c->pool, 2, sizeof(ngx_str_t))
79 == NGX_ERROR)
80 {
81 ngx_mail_session_internal_server_error(s);
82 return;
83 }
84
85 iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
86
87 s->buffer = ngx_create_temp_buf(c->pool, iscf->client_buffer_size);
88 if (s->buffer == NULL) {
89 ngx_mail_session_internal_server_error(s);
90 return;
91 }
92 }
93
94 s->mail_state = ngx_imap_start;
95 c->read->handler = ngx_mail_imap_auth_state;
96
97 ngx_mail_imap_auth_state(rev);
98 }
99
100
101 void
ngx_mail_imap_auth_state(ngx_event_t * rev)102 ngx_mail_imap_auth_state(ngx_event_t *rev)
103 {
104 u_char *p, *dst, *src, *end;
105 ngx_str_t *arg;
106 ngx_int_t rc;
107 ngx_uint_t tag, i;
108 ngx_connection_t *c;
109 ngx_mail_session_t *s;
110
111 c = rev->data;
112 s = c->data;
113
114 ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth state");
115
116 if (rev->timedout) {
117 ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
118 c->timedout = 1;
119 ngx_mail_close_connection(c);
120 return;
121 }
122
123 if (s->out.len) {
124 ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap send handler busy");
125 s->blocked = 1;
126 return;
127 }
128
129 s->blocked = 0;
130
131 rc = ngx_mail_read_command(s, c);
132
133 if (rc == NGX_AGAIN || rc == NGX_ERROR) {
134 return;
135 }
136
137 tag = 1;
138 s->text.len = 0;
139 ngx_str_set(&s->out, imap_ok);
140
141 if (rc == NGX_OK) {
142
143 ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth command: %i",
144 s->command);
145
146 if (s->backslash) {
147
148 arg = s->args.elts;
149
150 for (i = 0; i < s->args.nelts; i++) {
151 dst = arg[i].data;
152 end = dst + arg[i].len;
153
154 for (src = dst; src < end; dst++) {
155 *dst = *src;
156 if (*src++ == '\\') {
157 *dst = *src++;
158 }
159 }
160
161 arg[i].len = dst - arg[i].data;
162 }
163
164 s->backslash = 0;
165 }
166
167 switch (s->mail_state) {
168
169 case ngx_imap_start:
170
171 switch (s->command) {
172
173 case NGX_IMAP_LOGIN:
174 rc = ngx_mail_imap_login(s, c);
175 break;
176
177 case NGX_IMAP_AUTHENTICATE:
178 rc = ngx_mail_imap_authenticate(s, c);
179 tag = (rc != NGX_OK);
180 break;
181
182 case NGX_IMAP_CAPABILITY:
183 rc = ngx_mail_imap_capability(s, c);
184 break;
185
186 case NGX_IMAP_LOGOUT:
187 s->quit = 1;
188 ngx_str_set(&s->text, imap_bye);
189 break;
190
191 case NGX_IMAP_NOOP:
192 break;
193
194 case NGX_IMAP_STARTTLS:
195 rc = ngx_mail_imap_starttls(s, c);
196 break;
197
198 default:
199 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
200 break;
201 }
202
203 break;
204
205 case ngx_imap_auth_login_username:
206 rc = ngx_mail_auth_login_username(s, c, 0);
207
208 tag = 0;
209 ngx_str_set(&s->out, imap_password);
210 s->mail_state = ngx_imap_auth_login_password;
211
212 break;
213
214 case ngx_imap_auth_login_password:
215 rc = ngx_mail_auth_login_password(s, c);
216 break;
217
218 case ngx_imap_auth_plain:
219 rc = ngx_mail_auth_plain(s, c, 0);
220 break;
221
222 case ngx_imap_auth_cram_md5:
223 rc = ngx_mail_auth_cram_md5(s, c);
224 break;
225
226 case ngx_imap_auth_external:
227 rc = ngx_mail_auth_external(s, c, 0);
228 break;
229 }
230
231 } else if (rc == NGX_IMAP_NEXT) {
232 tag = 0;
233 ngx_str_set(&s->out, imap_next);
234 }
235
236 switch (rc) {
237
238 case NGX_DONE:
239 ngx_mail_auth(s, c);
240 return;
241
242 case NGX_ERROR:
243 ngx_mail_session_internal_server_error(s);
244 return;
245
246 case NGX_MAIL_PARSE_INVALID_COMMAND:
247 s->state = 0;
248 ngx_str_set(&s->out, imap_invalid_command);
249 s->mail_state = ngx_imap_start;
250 break;
251 }
252
253 if (tag) {
254 if (s->tag.len == 0) {
255 ngx_str_set(&s->tag, imap_star);
256 }
257
258 if (s->tagged_line.len < s->tag.len + s->text.len + s->out.len) {
259 s->tagged_line.len = s->tag.len + s->text.len + s->out.len;
260 s->tagged_line.data = ngx_pnalloc(c->pool, s->tagged_line.len);
261 if (s->tagged_line.data == NULL) {
262 ngx_mail_close_connection(c);
263 return;
264 }
265 }
266
267 p = s->tagged_line.data;
268
269 if (s->text.len) {
270 p = ngx_cpymem(p, s->text.data, s->text.len);
271 }
272
273 p = ngx_cpymem(p, s->tag.data, s->tag.len);
274 ngx_memcpy(p, s->out.data, s->out.len);
275
276 s->out.len = s->text.len + s->tag.len + s->out.len;
277 s->out.data = s->tagged_line.data;
278 }
279
280 if (rc != NGX_IMAP_NEXT) {
281 s->args.nelts = 0;
282
283 if (s->state) {
284 /* preserve tag */
285 s->arg_start = s->buffer->start + s->tag.len;
286 s->buffer->pos = s->arg_start;
287 s->buffer->last = s->arg_start;
288
289 } else {
290 s->buffer->pos = s->buffer->start;
291 s->buffer->last = s->buffer->start;
292 s->tag.len = 0;
293 }
294 }
295
296 ngx_mail_send(c->write);
297 }
298
299
300 static ngx_int_t
ngx_mail_imap_login(ngx_mail_session_t * s,ngx_connection_t * c)301 ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c)
302 {
303 ngx_str_t *arg;
304
305 #if (NGX_MAIL_SSL)
306 if (ngx_mail_starttls_only(s, c)) {
307 return NGX_MAIL_PARSE_INVALID_COMMAND;
308 }
309 #endif
310
311 arg = s->args.elts;
312
313 if (s->args.nelts != 2 || arg[0].len == 0) {
314 return NGX_MAIL_PARSE_INVALID_COMMAND;
315 }
316
317 s->login.len = arg[0].len;
318 s->login.data = ngx_pnalloc(c->pool, s->login.len);
319 if (s->login.data == NULL) {
320 return NGX_ERROR;
321 }
322
323 ngx_memcpy(s->login.data, arg[0].data, s->login.len);
324
325 s->passwd.len = arg[1].len;
326 s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
327 if (s->passwd.data == NULL) {
328 return NGX_ERROR;
329 }
330
331 ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len);
332
333 #if (NGX_DEBUG_MAIL_PASSWD)
334 ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
335 "imap login:\"%V\" passwd:\"%V\"",
336 &s->login, &s->passwd);
337 #else
338 ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
339 "imap login:\"%V\"", &s->login);
340 #endif
341
342 return NGX_DONE;
343 }
344
345
346 static ngx_int_t
ngx_mail_imap_authenticate(ngx_mail_session_t * s,ngx_connection_t * c)347 ngx_mail_imap_authenticate(ngx_mail_session_t *s, ngx_connection_t *c)
348 {
349 ngx_int_t rc;
350 ngx_mail_core_srv_conf_t *cscf;
351 ngx_mail_imap_srv_conf_t *iscf;
352
353 #if (NGX_MAIL_SSL)
354 if (ngx_mail_starttls_only(s, c)) {
355 return NGX_MAIL_PARSE_INVALID_COMMAND;
356 }
357 #endif
358
359 iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
360
361 rc = ngx_mail_auth_parse(s, c);
362
363 switch (rc) {
364
365 case NGX_MAIL_AUTH_LOGIN:
366
367 ngx_str_set(&s->out, imap_username);
368 s->mail_state = ngx_imap_auth_login_username;
369
370 return NGX_OK;
371
372 case NGX_MAIL_AUTH_LOGIN_USERNAME:
373
374 ngx_str_set(&s->out, imap_password);
375 s->mail_state = ngx_imap_auth_login_password;
376
377 return ngx_mail_auth_login_username(s, c, 1);
378
379 case NGX_MAIL_AUTH_PLAIN:
380
381 ngx_str_set(&s->out, imap_plain_next);
382 s->mail_state = ngx_imap_auth_plain;
383
384 return NGX_OK;
385
386 case NGX_MAIL_AUTH_CRAM_MD5:
387
388 if (!(iscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
389 return NGX_MAIL_PARSE_INVALID_COMMAND;
390 }
391
392 if (s->salt.data == NULL) {
393 cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
394
395 if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
396 return NGX_ERROR;
397 }
398 }
399
400 if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) {
401 s->mail_state = ngx_imap_auth_cram_md5;
402 return NGX_OK;
403 }
404
405 return NGX_ERROR;
406
407 case NGX_MAIL_AUTH_EXTERNAL:
408
409 if (!(iscf->auth_methods & NGX_MAIL_AUTH_EXTERNAL_ENABLED)) {
410 return NGX_MAIL_PARSE_INVALID_COMMAND;
411 }
412
413 ngx_str_set(&s->out, imap_username);
414 s->mail_state = ngx_imap_auth_external;
415
416 return NGX_OK;
417 }
418
419 return rc;
420 }
421
422
423 static ngx_int_t
ngx_mail_imap_capability(ngx_mail_session_t * s,ngx_connection_t * c)424 ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c)
425 {
426 ngx_mail_imap_srv_conf_t *iscf;
427
428 iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
429
430 #if (NGX_MAIL_SSL)
431
432 if (c->ssl == NULL) {
433 ngx_mail_ssl_conf_t *sslcf;
434
435 sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
436
437 if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
438 s->text = iscf->starttls_capability;
439 return NGX_OK;
440 }
441
442 if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
443 s->text = iscf->starttls_only_capability;
444 return NGX_OK;
445 }
446 }
447 #endif
448
449 s->text = iscf->capability;
450
451 return NGX_OK;
452 }
453
454
455 static ngx_int_t
ngx_mail_imap_starttls(ngx_mail_session_t * s,ngx_connection_t * c)456 ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c)
457 {
458 #if (NGX_MAIL_SSL)
459 ngx_mail_ssl_conf_t *sslcf;
460
461 if (c->ssl == NULL) {
462 sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
463 if (sslcf->starttls) {
464 c->read->handler = ngx_mail_starttls_handler;
465 return NGX_OK;
466 }
467 }
468
469 #endif
470
471 return NGX_MAIL_PARSE_INVALID_COMMAND;
472 }
473