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;
105 ngx_int_t rc;
106 ngx_uint_t tag;
107 ngx_connection_t *c;
108 ngx_mail_session_t *s;
109
110 c = rev->data;
111 s = c->data;
112
113 ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth state");
114
115 if (rev->timedout) {
116 ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
117 c->timedout = 1;
118 ngx_mail_close_connection(c);
119 return;
120 }
121
122 if (s->out.len) {
123 ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap send handler busy");
124 s->blocked = 1;
125
126 if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
127 ngx_mail_close_connection(c);
128 return;
129 }
130
131 return;
132 }
133
134 s->blocked = 0;
135
136 rc = ngx_mail_read_command(s, c);
137
138 if (rc == NGX_AGAIN) {
139 if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
140 ngx_mail_session_internal_server_error(s);
141 return;
142 }
143
144 return;
145 }
146
147 if (rc == NGX_ERROR) {
148 return;
149 }
150
151 tag = 1;
152 s->text.len = 0;
153 ngx_str_set(&s->out, imap_ok);
154
155 if (rc == NGX_OK) {
156
157 ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth command: %i",
158 s->command);
159
160 switch (s->mail_state) {
161
162 case ngx_imap_start:
163
164 switch (s->command) {
165
166 case NGX_IMAP_LOGIN:
167 rc = ngx_mail_imap_login(s, c);
168 break;
169
170 case NGX_IMAP_AUTHENTICATE:
171 rc = ngx_mail_imap_authenticate(s, c);
172 tag = (rc != NGX_OK);
173 break;
174
175 case NGX_IMAP_CAPABILITY:
176 rc = ngx_mail_imap_capability(s, c);
177 break;
178
179 case NGX_IMAP_LOGOUT:
180 s->quit = 1;
181 ngx_str_set(&s->text, imap_bye);
182 break;
183
184 case NGX_IMAP_NOOP:
185 break;
186
187 case NGX_IMAP_STARTTLS:
188 rc = ngx_mail_imap_starttls(s, c);
189 break;
190
191 default:
192 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
193 break;
194 }
195
196 break;
197
198 case ngx_imap_auth_login_username:
199 rc = ngx_mail_auth_login_username(s, c, 0);
200
201 tag = 0;
202 ngx_str_set(&s->out, imap_password);
203 s->mail_state = ngx_imap_auth_login_password;
204
205 break;
206
207 case ngx_imap_auth_login_password:
208 rc = ngx_mail_auth_login_password(s, c);
209 break;
210
211 case ngx_imap_auth_plain:
212 rc = ngx_mail_auth_plain(s, c, 0);
213 break;
214
215 case ngx_imap_auth_cram_md5:
216 rc = ngx_mail_auth_cram_md5(s, c);
217 break;
218
219 case ngx_imap_auth_external:
220 rc = ngx_mail_auth_external(s, c, 0);
221 break;
222 }
223
224 } else if (rc == NGX_IMAP_NEXT) {
225 tag = 0;
226 ngx_str_set(&s->out, imap_next);
227 }
228
229 if (s->buffer->pos < s->buffer->last) {
230 s->blocked = 1;
231 }
232
233 switch (rc) {
234
235 case NGX_DONE:
236 ngx_mail_auth(s, c);
237 return;
238
239 case NGX_ERROR:
240 ngx_mail_session_internal_server_error(s);
241 return;
242
243 case NGX_MAIL_PARSE_INVALID_COMMAND:
244 s->state = 0;
245 ngx_str_set(&s->out, imap_invalid_command);
246 s->mail_state = ngx_imap_start;
247 break;
248 }
249
250 if (tag) {
251 if (s->tag.len == 0) {
252 ngx_str_set(&s->tag, imap_star);
253 }
254
255 if (s->tagged_line.len < s->tag.len + s->text.len + s->out.len) {
256 s->tagged_line.len = s->tag.len + s->text.len + s->out.len;
257 s->tagged_line.data = ngx_pnalloc(c->pool, s->tagged_line.len);
258 if (s->tagged_line.data == NULL) {
259 ngx_mail_close_connection(c);
260 return;
261 }
262 }
263
264 p = s->tagged_line.data;
265
266 if (s->text.len) {
267 p = ngx_cpymem(p, s->text.data, s->text.len);
268 }
269
270 p = ngx_cpymem(p, s->tag.data, s->tag.len);
271 ngx_memcpy(p, s->out.data, s->out.len);
272
273 s->out.len = s->text.len + s->tag.len + s->out.len;
274 s->out.data = s->tagged_line.data;
275 }
276
277 if (rc != NGX_IMAP_NEXT) {
278 s->args.nelts = 0;
279
280 if (s->state) {
281 /* preserve tag */
282 s->arg_start = s->buffer->pos;
283
284 } else {
285 if (s->buffer->pos == s->buffer->last) {
286 s->buffer->pos = s->buffer->start;
287 s->buffer->last = s->buffer->start;
288 }
289
290 s->tag.len = 0;
291 }
292 }
293
294 if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
295 ngx_mail_session_internal_server_error(s);
296 return;
297 }
298
299 ngx_mail_send(c->write);
300 }
301
302
303 static ngx_int_t
ngx_mail_imap_login(ngx_mail_session_t * s,ngx_connection_t * c)304 ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c)
305 {
306 ngx_str_t *arg;
307
308 #if (NGX_MAIL_SSL)
309 if (ngx_mail_starttls_only(s, c)) {
310 return NGX_MAIL_PARSE_INVALID_COMMAND;
311 }
312 #endif
313
314 arg = s->args.elts;
315
316 if (s->args.nelts != 2 || arg[0].len == 0) {
317 return NGX_MAIL_PARSE_INVALID_COMMAND;
318 }
319
320 s->login.len = arg[0].len;
321 s->login.data = ngx_pnalloc(c->pool, s->login.len);
322 if (s->login.data == NULL) {
323 return NGX_ERROR;
324 }
325
326 ngx_memcpy(s->login.data, arg[0].data, s->login.len);
327
328 s->passwd.len = arg[1].len;
329 s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
330 if (s->passwd.data == NULL) {
331 return NGX_ERROR;
332 }
333
334 ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len);
335
336 #if (NGX_DEBUG_MAIL_PASSWD)
337 ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
338 "imap login:\"%V\" passwd:\"%V\"",
339 &s->login, &s->passwd);
340 #else
341 ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
342 "imap login:\"%V\"", &s->login);
343 #endif
344
345 return NGX_DONE;
346 }
347
348
349 static ngx_int_t
ngx_mail_imap_authenticate(ngx_mail_session_t * s,ngx_connection_t * c)350 ngx_mail_imap_authenticate(ngx_mail_session_t *s, ngx_connection_t *c)
351 {
352 ngx_int_t rc;
353 ngx_mail_core_srv_conf_t *cscf;
354 ngx_mail_imap_srv_conf_t *iscf;
355
356 #if (NGX_MAIL_SSL)
357 if (ngx_mail_starttls_only(s, c)) {
358 return NGX_MAIL_PARSE_INVALID_COMMAND;
359 }
360 #endif
361
362 iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
363
364 rc = ngx_mail_auth_parse(s, c);
365
366 switch (rc) {
367
368 case NGX_MAIL_AUTH_LOGIN:
369
370 ngx_str_set(&s->out, imap_username);
371 s->mail_state = ngx_imap_auth_login_username;
372
373 return NGX_OK;
374
375 case NGX_MAIL_AUTH_LOGIN_USERNAME:
376
377 ngx_str_set(&s->out, imap_password);
378 s->mail_state = ngx_imap_auth_login_password;
379
380 return ngx_mail_auth_login_username(s, c, 1);
381
382 case NGX_MAIL_AUTH_PLAIN:
383
384 ngx_str_set(&s->out, imap_plain_next);
385 s->mail_state = ngx_imap_auth_plain;
386
387 return NGX_OK;
388
389 case NGX_MAIL_AUTH_CRAM_MD5:
390
391 if (!(iscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
392 return NGX_MAIL_PARSE_INVALID_COMMAND;
393 }
394
395 if (s->salt.data == NULL) {
396 cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
397
398 if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
399 return NGX_ERROR;
400 }
401 }
402
403 if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) {
404 s->mail_state = ngx_imap_auth_cram_md5;
405 return NGX_OK;
406 }
407
408 return NGX_ERROR;
409
410 case NGX_MAIL_AUTH_EXTERNAL:
411
412 if (!(iscf->auth_methods & NGX_MAIL_AUTH_EXTERNAL_ENABLED)) {
413 return NGX_MAIL_PARSE_INVALID_COMMAND;
414 }
415
416 ngx_str_set(&s->out, imap_username);
417 s->mail_state = ngx_imap_auth_external;
418
419 return NGX_OK;
420 }
421
422 return rc;
423 }
424
425
426 static ngx_int_t
ngx_mail_imap_capability(ngx_mail_session_t * s,ngx_connection_t * c)427 ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c)
428 {
429 ngx_mail_imap_srv_conf_t *iscf;
430
431 iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
432
433 #if (NGX_MAIL_SSL)
434
435 if (c->ssl == NULL) {
436 ngx_mail_ssl_conf_t *sslcf;
437
438 sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
439
440 if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
441 s->text = iscf->starttls_capability;
442 return NGX_OK;
443 }
444
445 if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
446 s->text = iscf->starttls_only_capability;
447 return NGX_OK;
448 }
449 }
450 #endif
451
452 s->text = iscf->capability;
453
454 return NGX_OK;
455 }
456
457
458 static ngx_int_t
ngx_mail_imap_starttls(ngx_mail_session_t * s,ngx_connection_t * c)459 ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c)
460 {
461 #if (NGX_MAIL_SSL)
462 ngx_mail_ssl_conf_t *sslcf;
463
464 if (c->ssl == NULL) {
465 sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
466 if (sslcf->starttls) {
467 s->buffer->pos = s->buffer->start;
468 s->buffer->last = s->buffer->start;
469 c->read->handler = ngx_mail_starttls_handler;
470 return NGX_OK;
471 }
472 }
473
474 #endif
475
476 return NGX_MAIL_PARSE_INVALID_COMMAND;
477 }
478