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
127 if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
128 ngx_mail_close_connection(c);
129 return;
130 }
131
132 return;
133 }
134
135 s->blocked = 0;
136
137 rc = ngx_mail_read_command(s, c);
138
139 if (rc == NGX_AGAIN) {
140 if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
141 ngx_mail_session_internal_server_error(s);
142 return;
143 }
144
145 return;
146 }
147
148 if (rc == NGX_ERROR) {
149 return;
150 }
151
152 tag = 1;
153 s->text.len = 0;
154 ngx_str_set(&s->out, imap_ok);
155
156 if (rc == NGX_OK) {
157
158 ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth command: %i",
159 s->command);
160
161 if (s->backslash) {
162
163 arg = s->args.elts;
164
165 for (i = 0; i < s->args.nelts; i++) {
166 dst = arg[i].data;
167 end = dst + arg[i].len;
168
169 for (src = dst; src < end; dst++) {
170 *dst = *src;
171 if (*src++ == '\\') {
172 *dst = *src++;
173 }
174 }
175
176 arg[i].len = dst - arg[i].data;
177 }
178
179 s->backslash = 0;
180 }
181
182 switch (s->mail_state) {
183
184 case ngx_imap_start:
185
186 switch (s->command) {
187
188 case NGX_IMAP_LOGIN:
189 rc = ngx_mail_imap_login(s, c);
190 break;
191
192 case NGX_IMAP_AUTHENTICATE:
193 rc = ngx_mail_imap_authenticate(s, c);
194 tag = (rc != NGX_OK);
195 break;
196
197 case NGX_IMAP_CAPABILITY:
198 rc = ngx_mail_imap_capability(s, c);
199 break;
200
201 case NGX_IMAP_LOGOUT:
202 s->quit = 1;
203 ngx_str_set(&s->text, imap_bye);
204 break;
205
206 case NGX_IMAP_NOOP:
207 break;
208
209 case NGX_IMAP_STARTTLS:
210 rc = ngx_mail_imap_starttls(s, c);
211 break;
212
213 default:
214 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
215 break;
216 }
217
218 break;
219
220 case ngx_imap_auth_login_username:
221 rc = ngx_mail_auth_login_username(s, c, 0);
222
223 tag = 0;
224 ngx_str_set(&s->out, imap_password);
225 s->mail_state = ngx_imap_auth_login_password;
226
227 break;
228
229 case ngx_imap_auth_login_password:
230 rc = ngx_mail_auth_login_password(s, c);
231 break;
232
233 case ngx_imap_auth_plain:
234 rc = ngx_mail_auth_plain(s, c, 0);
235 break;
236
237 case ngx_imap_auth_cram_md5:
238 rc = ngx_mail_auth_cram_md5(s, c);
239 break;
240
241 case ngx_imap_auth_external:
242 rc = ngx_mail_auth_external(s, c, 0);
243 break;
244 }
245
246 } else if (rc == NGX_IMAP_NEXT) {
247 tag = 0;
248 ngx_str_set(&s->out, imap_next);
249 }
250
251 switch (rc) {
252
253 case NGX_DONE:
254 ngx_mail_auth(s, c);
255 return;
256
257 case NGX_ERROR:
258 ngx_mail_session_internal_server_error(s);
259 return;
260
261 case NGX_MAIL_PARSE_INVALID_COMMAND:
262 s->state = 0;
263 ngx_str_set(&s->out, imap_invalid_command);
264 s->mail_state = ngx_imap_start;
265 break;
266 }
267
268 if (tag) {
269 if (s->tag.len == 0) {
270 ngx_str_set(&s->tag, imap_star);
271 }
272
273 if (s->tagged_line.len < s->tag.len + s->text.len + s->out.len) {
274 s->tagged_line.len = s->tag.len + s->text.len + s->out.len;
275 s->tagged_line.data = ngx_pnalloc(c->pool, s->tagged_line.len);
276 if (s->tagged_line.data == NULL) {
277 ngx_mail_close_connection(c);
278 return;
279 }
280 }
281
282 p = s->tagged_line.data;
283
284 if (s->text.len) {
285 p = ngx_cpymem(p, s->text.data, s->text.len);
286 }
287
288 p = ngx_cpymem(p, s->tag.data, s->tag.len);
289 ngx_memcpy(p, s->out.data, s->out.len);
290
291 s->out.len = s->text.len + s->tag.len + s->out.len;
292 s->out.data = s->tagged_line.data;
293 }
294
295 if (rc != NGX_IMAP_NEXT) {
296 s->args.nelts = 0;
297
298 if (s->state) {
299 /* preserve tag */
300 s->arg_start = s->buffer->start + s->tag.len;
301 s->buffer->pos = s->arg_start;
302 s->buffer->last = s->arg_start;
303
304 } else {
305 s->buffer->pos = s->buffer->start;
306 s->buffer->last = s->buffer->start;
307 s->tag.len = 0;
308 }
309 }
310
311 if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
312 ngx_mail_session_internal_server_error(s);
313 return;
314 }
315
316 ngx_mail_send(c->write);
317 }
318
319
320 static ngx_int_t
ngx_mail_imap_login(ngx_mail_session_t * s,ngx_connection_t * c)321 ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c)
322 {
323 ngx_str_t *arg;
324
325 #if (NGX_MAIL_SSL)
326 if (ngx_mail_starttls_only(s, c)) {
327 return NGX_MAIL_PARSE_INVALID_COMMAND;
328 }
329 #endif
330
331 arg = s->args.elts;
332
333 if (s->args.nelts != 2 || arg[0].len == 0) {
334 return NGX_MAIL_PARSE_INVALID_COMMAND;
335 }
336
337 s->login.len = arg[0].len;
338 s->login.data = ngx_pnalloc(c->pool, s->login.len);
339 if (s->login.data == NULL) {
340 return NGX_ERROR;
341 }
342
343 ngx_memcpy(s->login.data, arg[0].data, s->login.len);
344
345 s->passwd.len = arg[1].len;
346 s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
347 if (s->passwd.data == NULL) {
348 return NGX_ERROR;
349 }
350
351 ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len);
352
353 #if (NGX_DEBUG_MAIL_PASSWD)
354 ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
355 "imap login:\"%V\" passwd:\"%V\"",
356 &s->login, &s->passwd);
357 #else
358 ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
359 "imap login:\"%V\"", &s->login);
360 #endif
361
362 return NGX_DONE;
363 }
364
365
366 static ngx_int_t
ngx_mail_imap_authenticate(ngx_mail_session_t * s,ngx_connection_t * c)367 ngx_mail_imap_authenticate(ngx_mail_session_t *s, ngx_connection_t *c)
368 {
369 ngx_int_t rc;
370 ngx_mail_core_srv_conf_t *cscf;
371 ngx_mail_imap_srv_conf_t *iscf;
372
373 #if (NGX_MAIL_SSL)
374 if (ngx_mail_starttls_only(s, c)) {
375 return NGX_MAIL_PARSE_INVALID_COMMAND;
376 }
377 #endif
378
379 iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
380
381 rc = ngx_mail_auth_parse(s, c);
382
383 switch (rc) {
384
385 case NGX_MAIL_AUTH_LOGIN:
386
387 ngx_str_set(&s->out, imap_username);
388 s->mail_state = ngx_imap_auth_login_username;
389
390 return NGX_OK;
391
392 case NGX_MAIL_AUTH_LOGIN_USERNAME:
393
394 ngx_str_set(&s->out, imap_password);
395 s->mail_state = ngx_imap_auth_login_password;
396
397 return ngx_mail_auth_login_username(s, c, 1);
398
399 case NGX_MAIL_AUTH_PLAIN:
400
401 ngx_str_set(&s->out, imap_plain_next);
402 s->mail_state = ngx_imap_auth_plain;
403
404 return NGX_OK;
405
406 case NGX_MAIL_AUTH_CRAM_MD5:
407
408 if (!(iscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
409 return NGX_MAIL_PARSE_INVALID_COMMAND;
410 }
411
412 if (s->salt.data == NULL) {
413 cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
414
415 if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
416 return NGX_ERROR;
417 }
418 }
419
420 if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) {
421 s->mail_state = ngx_imap_auth_cram_md5;
422 return NGX_OK;
423 }
424
425 return NGX_ERROR;
426
427 case NGX_MAIL_AUTH_EXTERNAL:
428
429 if (!(iscf->auth_methods & NGX_MAIL_AUTH_EXTERNAL_ENABLED)) {
430 return NGX_MAIL_PARSE_INVALID_COMMAND;
431 }
432
433 ngx_str_set(&s->out, imap_username);
434 s->mail_state = ngx_imap_auth_external;
435
436 return NGX_OK;
437 }
438
439 return rc;
440 }
441
442
443 static ngx_int_t
ngx_mail_imap_capability(ngx_mail_session_t * s,ngx_connection_t * c)444 ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c)
445 {
446 ngx_mail_imap_srv_conf_t *iscf;
447
448 iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
449
450 #if (NGX_MAIL_SSL)
451
452 if (c->ssl == NULL) {
453 ngx_mail_ssl_conf_t *sslcf;
454
455 sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
456
457 if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
458 s->text = iscf->starttls_capability;
459 return NGX_OK;
460 }
461
462 if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
463 s->text = iscf->starttls_only_capability;
464 return NGX_OK;
465 }
466 }
467 #endif
468
469 s->text = iscf->capability;
470
471 return NGX_OK;
472 }
473
474
475 static ngx_int_t
ngx_mail_imap_starttls(ngx_mail_session_t * s,ngx_connection_t * c)476 ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c)
477 {
478 #if (NGX_MAIL_SSL)
479 ngx_mail_ssl_conf_t *sslcf;
480
481 if (c->ssl == NULL) {
482 sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
483 if (sslcf->starttls) {
484 c->read->handler = ngx_mail_starttls_handler;
485 return NGX_OK;
486 }
487 }
488
489 #endif
490
491 return NGX_MAIL_PARSE_INVALID_COMMAND;
492 }
493