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_pop3_module.h>
13 #include <ngx_mail_imap_module.h>
14 #include <ngx_mail_smtp_module.h>
15
16
17 ngx_int_t
ngx_mail_pop3_parse_command(ngx_mail_session_t * s)18 ngx_mail_pop3_parse_command(ngx_mail_session_t *s)
19 {
20 u_char ch, *p, *c, c0, c1, c2, c3;
21 ngx_str_t *arg;
22 enum {
23 sw_start = 0,
24 sw_spaces_before_argument,
25 sw_argument,
26 sw_almost_done
27 } state;
28
29 state = s->state;
30
31 for (p = s->buffer->pos; p < s->buffer->last; p++) {
32 ch = *p;
33
34 switch (state) {
35
36 /* POP3 command */
37 case sw_start:
38 if (ch == ' ' || ch == CR || ch == LF) {
39 c = s->buffer->start;
40
41 if (p - c == 4) {
42
43 c0 = ngx_toupper(c[0]);
44 c1 = ngx_toupper(c[1]);
45 c2 = ngx_toupper(c[2]);
46 c3 = ngx_toupper(c[3]);
47
48 if (c0 == 'U' && c1 == 'S' && c2 == 'E' && c3 == 'R')
49 {
50 s->command = NGX_POP3_USER;
51
52 } else if (c0 == 'P' && c1 == 'A' && c2 == 'S' && c3 == 'S')
53 {
54 s->command = NGX_POP3_PASS;
55
56 } else if (c0 == 'A' && c1 == 'P' && c2 == 'O' && c3 == 'P')
57 {
58 s->command = NGX_POP3_APOP;
59
60 } else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
61 {
62 s->command = NGX_POP3_QUIT;
63
64 } else if (c0 == 'C' && c1 == 'A' && c2 == 'P' && c3 == 'A')
65 {
66 s->command = NGX_POP3_CAPA;
67
68 } else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
69 {
70 s->command = NGX_POP3_AUTH;
71
72 } else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
73 {
74 s->command = NGX_POP3_NOOP;
75 #if (NGX_MAIL_SSL)
76 } else if (c0 == 'S' && c1 == 'T' && c2 == 'L' && c3 == 'S')
77 {
78 s->command = NGX_POP3_STLS;
79 #endif
80 } else {
81 goto invalid;
82 }
83
84 } else {
85 goto invalid;
86 }
87
88 switch (ch) {
89 case ' ':
90 state = sw_spaces_before_argument;
91 break;
92 case CR:
93 state = sw_almost_done;
94 break;
95 case LF:
96 goto done;
97 }
98 break;
99 }
100
101 if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
102 goto invalid;
103 }
104
105 break;
106
107 case sw_spaces_before_argument:
108 switch (ch) {
109 case ' ':
110 break;
111 case CR:
112 state = sw_almost_done;
113 s->arg_end = p;
114 break;
115 case LF:
116 s->arg_end = p;
117 goto done;
118 default:
119 if (s->args.nelts <= 2) {
120 state = sw_argument;
121 s->arg_start = p;
122 break;
123 }
124 goto invalid;
125 }
126 break;
127
128 case sw_argument:
129 switch (ch) {
130
131 case ' ':
132
133 /*
134 * the space should be considered as part of the at username
135 * or password, but not of argument in other commands
136 */
137
138 if (s->command == NGX_POP3_USER
139 || s->command == NGX_POP3_PASS)
140 {
141 break;
142 }
143
144 /* fall through */
145
146 case CR:
147 case LF:
148 arg = ngx_array_push(&s->args);
149 if (arg == NULL) {
150 return NGX_ERROR;
151 }
152 arg->len = p - s->arg_start;
153 arg->data = s->arg_start;
154 s->arg_start = NULL;
155
156 switch (ch) {
157 case ' ':
158 state = sw_spaces_before_argument;
159 break;
160 case CR:
161 state = sw_almost_done;
162 break;
163 case LF:
164 goto done;
165 }
166 break;
167
168 default:
169 break;
170 }
171 break;
172
173 case sw_almost_done:
174 switch (ch) {
175 case LF:
176 goto done;
177 default:
178 goto invalid;
179 }
180 }
181 }
182
183 s->buffer->pos = p;
184 s->state = state;
185
186 return NGX_AGAIN;
187
188 done:
189
190 s->buffer->pos = p + 1;
191
192 if (s->arg_start) {
193 arg = ngx_array_push(&s->args);
194 if (arg == NULL) {
195 return NGX_ERROR;
196 }
197 arg->len = s->arg_end - s->arg_start;
198 arg->data = s->arg_start;
199 s->arg_start = NULL;
200 }
201
202 s->state = (s->command != NGX_POP3_AUTH) ? sw_start : sw_argument;
203
204 return NGX_OK;
205
206 invalid:
207
208 s->state = sw_start;
209 s->arg_start = NULL;
210
211 return NGX_MAIL_PARSE_INVALID_COMMAND;
212 }
213
214
215 ngx_int_t
ngx_mail_imap_parse_command(ngx_mail_session_t * s)216 ngx_mail_imap_parse_command(ngx_mail_session_t *s)
217 {
218 u_char ch, *p, *c;
219 ngx_str_t *arg;
220 enum {
221 sw_start = 0,
222 sw_spaces_before_command,
223 sw_command,
224 sw_spaces_before_argument,
225 sw_argument,
226 sw_backslash,
227 sw_literal,
228 sw_no_sync_literal_argument,
229 sw_start_literal_argument,
230 sw_literal_argument,
231 sw_end_literal_argument,
232 sw_almost_done
233 } state;
234
235 state = s->state;
236
237 for (p = s->buffer->pos; p < s->buffer->last; p++) {
238 ch = *p;
239
240 switch (state) {
241
242 /* IMAP tag */
243 case sw_start:
244 switch (ch) {
245 case ' ':
246 s->tag.len = p - s->buffer->start + 1;
247 s->tag.data = s->buffer->start;
248 state = sw_spaces_before_command;
249 break;
250 case CR:
251 s->state = sw_start;
252 return NGX_MAIL_PARSE_INVALID_COMMAND;
253 case LF:
254 s->state = sw_start;
255 return NGX_MAIL_PARSE_INVALID_COMMAND;
256 }
257 break;
258
259 case sw_spaces_before_command:
260 switch (ch) {
261 case ' ':
262 break;
263 case CR:
264 s->state = sw_start;
265 return NGX_MAIL_PARSE_INVALID_COMMAND;
266 case LF:
267 s->state = sw_start;
268 return NGX_MAIL_PARSE_INVALID_COMMAND;
269 default:
270 s->cmd_start = p;
271 state = sw_command;
272 break;
273 }
274 break;
275
276 case sw_command:
277 if (ch == ' ' || ch == CR || ch == LF) {
278
279 c = s->cmd_start;
280
281 switch (p - c) {
282
283 case 4:
284 if ((c[0] == 'N' || c[0] == 'n')
285 && (c[1] == 'O'|| c[1] == 'o')
286 && (c[2] == 'O'|| c[2] == 'o')
287 && (c[3] == 'P'|| c[3] == 'p'))
288 {
289 s->command = NGX_IMAP_NOOP;
290
291 } else {
292 goto invalid;
293 }
294 break;
295
296 case 5:
297 if ((c[0] == 'L'|| c[0] == 'l')
298 && (c[1] == 'O'|| c[1] == 'o')
299 && (c[2] == 'G'|| c[2] == 'g')
300 && (c[3] == 'I'|| c[3] == 'i')
301 && (c[4] == 'N'|| c[4] == 'n'))
302 {
303 s->command = NGX_IMAP_LOGIN;
304
305 } else {
306 goto invalid;
307 }
308 break;
309
310 case 6:
311 if ((c[0] == 'L'|| c[0] == 'l')
312 && (c[1] == 'O'|| c[1] == 'o')
313 && (c[2] == 'G'|| c[2] == 'g')
314 && (c[3] == 'O'|| c[3] == 'o')
315 && (c[4] == 'U'|| c[4] == 'u')
316 && (c[5] == 'T'|| c[5] == 't'))
317 {
318 s->command = NGX_IMAP_LOGOUT;
319
320 } else {
321 goto invalid;
322 }
323 break;
324
325 #if (NGX_MAIL_SSL)
326 case 8:
327 if ((c[0] == 'S'|| c[0] == 's')
328 && (c[1] == 'T'|| c[1] == 't')
329 && (c[2] == 'A'|| c[2] == 'a')
330 && (c[3] == 'R'|| c[3] == 'r')
331 && (c[4] == 'T'|| c[4] == 't')
332 && (c[5] == 'T'|| c[5] == 't')
333 && (c[6] == 'L'|| c[6] == 'l')
334 && (c[7] == 'S'|| c[7] == 's'))
335 {
336 s->command = NGX_IMAP_STARTTLS;
337
338 } else {
339 goto invalid;
340 }
341 break;
342 #endif
343
344 case 10:
345 if ((c[0] == 'C'|| c[0] == 'c')
346 && (c[1] == 'A'|| c[1] == 'a')
347 && (c[2] == 'P'|| c[2] == 'p')
348 && (c[3] == 'A'|| c[3] == 'a')
349 && (c[4] == 'B'|| c[4] == 'b')
350 && (c[5] == 'I'|| c[5] == 'i')
351 && (c[6] == 'L'|| c[6] == 'l')
352 && (c[7] == 'I'|| c[7] == 'i')
353 && (c[8] == 'T'|| c[8] == 't')
354 && (c[9] == 'Y'|| c[9] == 'y'))
355 {
356 s->command = NGX_IMAP_CAPABILITY;
357
358 } else {
359 goto invalid;
360 }
361 break;
362
363 case 12:
364 if ((c[0] == 'A'|| c[0] == 'a')
365 && (c[1] == 'U'|| c[1] == 'u')
366 && (c[2] == 'T'|| c[2] == 't')
367 && (c[3] == 'H'|| c[3] == 'h')
368 && (c[4] == 'E'|| c[4] == 'e')
369 && (c[5] == 'N'|| c[5] == 'n')
370 && (c[6] == 'T'|| c[6] == 't')
371 && (c[7] == 'I'|| c[7] == 'i')
372 && (c[8] == 'C'|| c[8] == 'c')
373 && (c[9] == 'A'|| c[9] == 'a')
374 && (c[10] == 'T'|| c[10] == 't')
375 && (c[11] == 'E'|| c[11] == 'e'))
376 {
377 s->command = NGX_IMAP_AUTHENTICATE;
378
379 } else {
380 goto invalid;
381 }
382 break;
383
384 default:
385 goto invalid;
386 }
387
388 switch (ch) {
389 case ' ':
390 state = sw_spaces_before_argument;
391 break;
392 case CR:
393 state = sw_almost_done;
394 break;
395 case LF:
396 goto done;
397 }
398 break;
399 }
400
401 if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
402 goto invalid;
403 }
404
405 break;
406
407 case sw_spaces_before_argument:
408 switch (ch) {
409 case ' ':
410 break;
411 case CR:
412 state = sw_almost_done;
413 s->arg_end = p;
414 break;
415 case LF:
416 s->arg_end = p;
417 goto done;
418 case '"':
419 if (s->args.nelts <= 2) {
420 s->quoted = 1;
421 s->arg_start = p + 1;
422 state = sw_argument;
423 break;
424 }
425 goto invalid;
426 case '{':
427 if (s->args.nelts <= 2) {
428 state = sw_literal;
429 break;
430 }
431 goto invalid;
432 default:
433 if (s->args.nelts <= 2) {
434 s->arg_start = p;
435 state = sw_argument;
436 break;
437 }
438 goto invalid;
439 }
440 break;
441
442 case sw_argument:
443 if (ch == ' ' && s->quoted) {
444 break;
445 }
446
447 switch (ch) {
448 case '"':
449 if (!s->quoted) {
450 break;
451 }
452 s->quoted = 0;
453 /* fall through */
454 case ' ':
455 case CR:
456 case LF:
457 arg = ngx_array_push(&s->args);
458 if (arg == NULL) {
459 return NGX_ERROR;
460 }
461 arg->len = p - s->arg_start;
462 arg->data = s->arg_start;
463 s->arg_start = NULL;
464
465 switch (ch) {
466 case '"':
467 case ' ':
468 state = sw_spaces_before_argument;
469 break;
470 case CR:
471 state = sw_almost_done;
472 break;
473 case LF:
474 goto done;
475 }
476 break;
477 case '\\':
478 if (s->quoted) {
479 s->backslash = 1;
480 state = sw_backslash;
481 }
482 break;
483 }
484 break;
485
486 case sw_backslash:
487 switch (ch) {
488 case CR:
489 case LF:
490 goto invalid;
491 default:
492 state = sw_argument;
493 }
494 break;
495
496 case sw_literal:
497 if (ch >= '0' && ch <= '9') {
498 s->literal_len = s->literal_len * 10 + (ch - '0');
499 break;
500 }
501 if (ch == '}') {
502 state = sw_start_literal_argument;
503 break;
504 }
505 if (ch == '+') {
506 state = sw_no_sync_literal_argument;
507 break;
508 }
509 goto invalid;
510
511 case sw_no_sync_literal_argument:
512 if (ch == '}') {
513 s->no_sync_literal = 1;
514 state = sw_start_literal_argument;
515 break;
516 }
517 goto invalid;
518
519 case sw_start_literal_argument:
520 switch (ch) {
521 case CR:
522 break;
523 case LF:
524 s->buffer->pos = p + 1;
525 s->arg_start = p + 1;
526 if (s->no_sync_literal == 0) {
527 s->state = sw_literal_argument;
528 return NGX_IMAP_NEXT;
529 }
530 state = sw_literal_argument;
531 s->no_sync_literal = 0;
532 break;
533 default:
534 goto invalid;
535 }
536 break;
537
538 case sw_literal_argument:
539 if (s->literal_len && --s->literal_len) {
540 break;
541 }
542
543 arg = ngx_array_push(&s->args);
544 if (arg == NULL) {
545 return NGX_ERROR;
546 }
547 arg->len = p + 1 - s->arg_start;
548 arg->data = s->arg_start;
549 s->arg_start = NULL;
550 state = sw_end_literal_argument;
551
552 break;
553
554 case sw_end_literal_argument:
555 switch (ch) {
556 case '{':
557 if (s->args.nelts <= 2) {
558 state = sw_literal;
559 break;
560 }
561 goto invalid;
562 case CR:
563 state = sw_almost_done;
564 break;
565 case LF:
566 goto done;
567 default:
568 state = sw_spaces_before_argument;
569 break;
570 }
571 break;
572
573 case sw_almost_done:
574 switch (ch) {
575 case LF:
576 goto done;
577 default:
578 goto invalid;
579 }
580 }
581 }
582
583 s->buffer->pos = p;
584 s->state = state;
585
586 return NGX_AGAIN;
587
588 done:
589
590 s->buffer->pos = p + 1;
591
592 if (s->arg_start) {
593 arg = ngx_array_push(&s->args);
594 if (arg == NULL) {
595 return NGX_ERROR;
596 }
597 arg->len = s->arg_end - s->arg_start;
598 arg->data = s->arg_start;
599
600 s->arg_start = NULL;
601 s->cmd_start = NULL;
602 s->quoted = 0;
603 s->no_sync_literal = 0;
604 s->literal_len = 0;
605 }
606
607 s->state = (s->command != NGX_IMAP_AUTHENTICATE) ? sw_start : sw_argument;
608
609 return NGX_OK;
610
611 invalid:
612
613 s->state = sw_start;
614 s->quoted = 0;
615 s->no_sync_literal = 0;
616 s->literal_len = 0;
617
618 return NGX_MAIL_PARSE_INVALID_COMMAND;
619 }
620
621
622 ngx_int_t
ngx_mail_smtp_parse_command(ngx_mail_session_t * s)623 ngx_mail_smtp_parse_command(ngx_mail_session_t *s)
624 {
625 u_char ch, *p, *c, c0, c1, c2, c3;
626 ngx_str_t *arg;
627 enum {
628 sw_start = 0,
629 sw_command,
630 sw_invalid,
631 sw_spaces_before_argument,
632 sw_argument,
633 sw_almost_done
634 } state;
635
636 state = s->state;
637
638 for (p = s->buffer->pos; p < s->buffer->last; p++) {
639 ch = *p;
640
641 switch (state) {
642
643 /* SMTP command */
644 case sw_start:
645 s->cmd_start = p;
646 state = sw_command;
647
648 /* fall through */
649
650 case sw_command:
651 if (ch == ' ' || ch == CR || ch == LF) {
652 c = s->cmd_start;
653
654 if (p - c == 4) {
655
656 c0 = ngx_toupper(c[0]);
657 c1 = ngx_toupper(c[1]);
658 c2 = ngx_toupper(c[2]);
659 c3 = ngx_toupper(c[3]);
660
661 if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'O')
662 {
663 s->command = NGX_SMTP_HELO;
664
665 } else if (c0 == 'E' && c1 == 'H' && c2 == 'L' && c3 == 'O')
666 {
667 s->command = NGX_SMTP_EHLO;
668
669 } else if (c0 == 'Q' && c1 == 'U' && c2 == 'I' && c3 == 'T')
670 {
671 s->command = NGX_SMTP_QUIT;
672
673 } else if (c0 == 'A' && c1 == 'U' && c2 == 'T' && c3 == 'H')
674 {
675 s->command = NGX_SMTP_AUTH;
676
677 } else if (c0 == 'N' && c1 == 'O' && c2 == 'O' && c3 == 'P')
678 {
679 s->command = NGX_SMTP_NOOP;
680
681 } else if (c0 == 'M' && c1 == 'A' && c2 == 'I' && c3 == 'L')
682 {
683 s->command = NGX_SMTP_MAIL;
684
685 } else if (c0 == 'R' && c1 == 'S' && c2 == 'E' && c3 == 'T')
686 {
687 s->command = NGX_SMTP_RSET;
688
689 } else if (c0 == 'R' && c1 == 'C' && c2 == 'P' && c3 == 'T')
690 {
691 s->command = NGX_SMTP_RCPT;
692
693 } else if (c0 == 'V' && c1 == 'R' && c2 == 'F' && c3 == 'Y')
694 {
695 s->command = NGX_SMTP_VRFY;
696
697 } else if (c0 == 'E' && c1 == 'X' && c2 == 'P' && c3 == 'N')
698 {
699 s->command = NGX_SMTP_EXPN;
700
701 } else if (c0 == 'H' && c1 == 'E' && c2 == 'L' && c3 == 'P')
702 {
703 s->command = NGX_SMTP_HELP;
704
705 } else {
706 goto invalid;
707 }
708 #if (NGX_MAIL_SSL)
709 } else if (p - c == 8) {
710
711 if ((c[0] == 'S'|| c[0] == 's')
712 && (c[1] == 'T'|| c[1] == 't')
713 && (c[2] == 'A'|| c[2] == 'a')
714 && (c[3] == 'R'|| c[3] == 'r')
715 && (c[4] == 'T'|| c[4] == 't')
716 && (c[5] == 'T'|| c[5] == 't')
717 && (c[6] == 'L'|| c[6] == 'l')
718 && (c[7] == 'S'|| c[7] == 's'))
719 {
720 s->command = NGX_SMTP_STARTTLS;
721
722 } else {
723 goto invalid;
724 }
725 #endif
726 } else {
727 goto invalid;
728 }
729
730 s->cmd.data = s->cmd_start;
731 s->cmd.len = p - s->cmd_start;
732
733 switch (ch) {
734 case ' ':
735 state = sw_spaces_before_argument;
736 break;
737 case CR:
738 state = sw_almost_done;
739 break;
740 case LF:
741 goto done;
742 }
743 break;
744 }
745
746 if ((ch < 'A' || ch > 'Z') && (ch < 'a' || ch > 'z')) {
747 goto invalid;
748 }
749
750 break;
751
752 case sw_invalid:
753 goto invalid;
754
755 case sw_spaces_before_argument:
756 switch (ch) {
757 case ' ':
758 break;
759 case CR:
760 state = sw_almost_done;
761 s->arg_end = p;
762 break;
763 case LF:
764 s->arg_end = p;
765 goto done;
766 default:
767 if (s->args.nelts <= 10) {
768 state = sw_argument;
769 s->arg_start = p;
770 break;
771 }
772 goto invalid;
773 }
774 break;
775
776 case sw_argument:
777 switch (ch) {
778 case ' ':
779 case CR:
780 case LF:
781 arg = ngx_array_push(&s->args);
782 if (arg == NULL) {
783 return NGX_ERROR;
784 }
785 arg->len = p - s->arg_start;
786 arg->data = s->arg_start;
787 s->arg_start = NULL;
788
789 switch (ch) {
790 case ' ':
791 state = sw_spaces_before_argument;
792 break;
793 case CR:
794 state = sw_almost_done;
795 break;
796 case LF:
797 goto done;
798 }
799 break;
800
801 default:
802 break;
803 }
804 break;
805
806 case sw_almost_done:
807 switch (ch) {
808 case LF:
809 goto done;
810 default:
811 goto invalid;
812 }
813 }
814 }
815
816 s->buffer->pos = p;
817 s->state = state;
818
819 return NGX_AGAIN;
820
821 done:
822
823 s->buffer->pos = p + 1;
824
825 if (s->arg_start) {
826 arg = ngx_array_push(&s->args);
827 if (arg == NULL) {
828 return NGX_ERROR;
829 }
830 arg->len = s->arg_end - s->arg_start;
831 arg->data = s->arg_start;
832 s->arg_start = NULL;
833 }
834
835 s->state = (s->command != NGX_SMTP_AUTH) ? sw_start : sw_argument;
836
837 return NGX_OK;
838
839 invalid:
840
841 s->state = sw_invalid;
842 s->arg_start = NULL;
843
844 /* skip invalid command till LF */
845
846 for (p = s->buffer->pos; p < s->buffer->last; p++) {
847 if (*p == LF) {
848 s->state = sw_start;
849 p++;
850 break;
851 }
852 }
853
854 s->buffer->pos = p;
855
856 return NGX_MAIL_PARSE_INVALID_COMMAND;
857 }
858
859
860 ngx_int_t
ngx_mail_auth_parse(ngx_mail_session_t * s,ngx_connection_t * c)861 ngx_mail_auth_parse(ngx_mail_session_t *s, ngx_connection_t *c)
862 {
863 ngx_str_t *arg;
864
865 #if (NGX_MAIL_SSL)
866 if (ngx_mail_starttls_only(s, c)) {
867 return NGX_MAIL_PARSE_INVALID_COMMAND;
868 }
869 #endif
870
871 if (s->args.nelts == 0) {
872 return NGX_MAIL_PARSE_INVALID_COMMAND;
873 }
874
875 arg = s->args.elts;
876
877 if (arg[0].len == 5) {
878
879 if (ngx_strncasecmp(arg[0].data, (u_char *) "LOGIN", 5) == 0) {
880
881 if (s->args.nelts == 1) {
882 return NGX_MAIL_AUTH_LOGIN;
883 }
884
885 if (s->args.nelts == 2) {
886 return NGX_MAIL_AUTH_LOGIN_USERNAME;
887 }
888
889 return NGX_MAIL_PARSE_INVALID_COMMAND;
890 }
891
892 if (ngx_strncasecmp(arg[0].data, (u_char *) "PLAIN", 5) == 0) {
893
894 if (s->args.nelts == 1) {
895 return NGX_MAIL_AUTH_PLAIN;
896 }
897
898 if (s->args.nelts == 2) {
899 return ngx_mail_auth_plain(s, c, 1);
900 }
901 }
902
903 return NGX_MAIL_PARSE_INVALID_COMMAND;
904 }
905
906 if (arg[0].len == 8) {
907
908 if (ngx_strncasecmp(arg[0].data, (u_char *) "CRAM-MD5", 8) == 0) {
909
910 if (s->args.nelts != 1) {
911 return NGX_MAIL_PARSE_INVALID_COMMAND;
912 }
913
914 return NGX_MAIL_AUTH_CRAM_MD5;
915 }
916
917 if (ngx_strncasecmp(arg[0].data, (u_char *) "EXTERNAL", 8) == 0) {
918
919 if (s->args.nelts == 1) {
920 return NGX_MAIL_AUTH_EXTERNAL;
921 }
922
923 if (s->args.nelts == 2) {
924 return ngx_mail_auth_external(s, c, 1);
925 }
926 }
927
928 return NGX_MAIL_PARSE_INVALID_COMMAND;
929 }
930
931 return NGX_MAIL_PARSE_INVALID_COMMAND;
932 }
933