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src/mail/ngx_mail_imap_handler.c - nginx source code

Global variables defined

Functions defined

Source code


  2. /*
  3. * Copyright (C) Igor Sysoev
  4. * Copyright (C) Nginx, Inc.
  5. */


  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>


  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);


  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;


  36. void
  37. ‌ngx_mail_imap_init_session(ngx_mail_session_t *s, ngx_connection_t *c)
  38. {
  39.     ngx_mail_core_srv_conf_t  *cscf;

  41.     cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);

  43.     ngx_str_set(&s->out, imap_greeting);

  45.     c->read->handler = ngx_mail_imap_init_protocol;

  47.     ngx_add_timer(c->read, cscf->timeout);

  49.     if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
  50.         ngx_mail_close_connection(c);
  51.     }

  53.     ngx_mail_send(c->write);
  54. }


  57. void
  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;

  64.     c = rev->data;

  66.     c->log->action = "in auth state";

  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.     }

  75.     s = c->data;

  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.         }

  85.         iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);

  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.     }

  94.     s->mail_state = ngx_imap_start;
  95.     c->read->handler = ngx_mail_imap_auth_state;

  97.     ngx_mail_imap_auth_state(rev);
  98. }


  101. void
  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;

  110.     c = rev->data;
  111.     s = c->data;

  113.     ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth state");

  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.     }

  122.     if (s->out.len) {
  123.         ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap send handler busy");
  124.         s->blocked = 1;

  126.         if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
  127.             ngx_mail_close_connection(c);
  128.             return;
  129.         }

  131.         return;
  132.     }

  134.     s->blocked = 0;

  136.     rc = ngx_mail_read_command(s, c);

  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.         }

  144.         return;
  145.     }

  147.     if (rc == NGX_ERROR) {
  148.         return;
  149.     }

  151.     tag = 1;
  152.     s->text.len = 0;
  153.     ngx_str_set(&s->out, imap_ok);

  155.     if (rc == NGX_OK) {

  157.         ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth command: %i",
  158.                        s->command);

  160.         switch (s->mail_state) {

  162.         case ngx_imap_start:

  164.             switch (s->command) {

  166.             case NGX_IMAP_LOGIN:
  167.                 rc = ngx_mail_imap_login(s, c);
  168.                 break;

  170.             case NGX_IMAP_AUTHENTICATE:
  171.                 rc = ngx_mail_imap_authenticate(s, c);
  172.                 tag = (rc != NGX_OK);
  173.                 break;

  175.             case NGX_IMAP_CAPABILITY:
  176.                 rc = ngx_mail_imap_capability(s, c);
  177.                 break;

  179.             case NGX_IMAP_LOGOUT:
  180.                 s->quit = 1;
  181.                 ngx_str_set(&s->text, imap_bye);
  182.                 break;

  184.             case NGX_IMAP_NOOP:
  185.                 break;

  187.             case NGX_IMAP_STARTTLS:
  188.                 rc = ngx_mail_imap_starttls(s, c);
  189.                 break;

  191.             default:
  192.                 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
  193.                 break;
  194.             }

  196.             break;

  198.         case ngx_imap_auth_login_username:
  199.             rc = ngx_mail_auth_login_username(s, c, 0);

  201.             tag = 0;
  202.             ngx_str_set(&s->out, imap_password);
  203.             s->mail_state = ngx_imap_auth_login_password;

  205.             break;

  207.         case ngx_imap_auth_login_password:
  208.             rc = ngx_mail_auth_login_password(s, c);
  209.             break;

  211.         case ngx_imap_auth_plain:
  212.             rc = ngx_mail_auth_plain(s, c, 0);
  213.             break;

  215.         case ngx_imap_auth_cram_md5:
  216.             rc = ngx_mail_auth_cram_md5(s, c);
  217.             break;

  219.         case ngx_imap_auth_external:
  220.             rc = ngx_mail_auth_external(s, c, 0);
  221.             break;
  222.         }

  224.     } else if (rc == NGX_IMAP_NEXT) {
  225.         tag = 0;
  226.         ngx_str_set(&s->out, imap_next);
  227.     }

  229.     if (s->buffer->pos < s->buffer->last) {
  230.         s->blocked = 1;
  231.     }

  233.     switch (rc) {

  235.     case NGX_DONE:
  236.         ngx_mail_auth(s, c);
  237.         return;

  239.     case NGX_ERROR:
  240.         ngx_mail_session_internal_server_error(s);
  241.         return;

  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.     }

  250.     if (tag) {
  251.         if (s->tag.len == 0) {
  252.             ngx_str_set(&s->tag, imap_star);
  253.         }

  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.         }

  264.         p = s->tagged_line.data;

  266.         if (s->text.len) {
  267.             p = ngx_cpymem(p, s->text.data, s->text.len);
  268.         }

  270.         p = ngx_cpymem(p, s->tag.data, s->tag.len);
  271.         ngx_memcpy(p, s->out.data, s->out.len);

  273.         s->out.len = s->text.len + s->tag.len + s->out.len;
  274.         s->out.data = s->tagged_line.data;
  275.     }

  277.     if (rc != NGX_IMAP_NEXT) {
  278.         s->args.nelts = 0;

  280.         if (s->state) {
  281.             /* preserve tag */
  282.             s->arg_start = s->buffer->pos;

  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.             }

  290.             s->tag.len = 0;
  291.         }
  292.     }

  294.     if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
  295.         ngx_mail_session_internal_server_error(s);
  296.         return;
  297.     }

  299.     ngx_mail_send(c->write);
  300. }


  303. static ngx_int_t
  304. ‌ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c)
  305. {
  306.     ngx_str_t  *arg;

  308. #if (NGX_MAIL_SSL)
  309.     if (ngx_mail_starttls_only(s, c)) {
  310.         return NGX_MAIL_PARSE_INVALID_COMMAND;
  311.     }
  312. #endif

  314.     arg = s->args.elts;

  316.     if (s->args.nelts != 2 || arg[0].len == 0) {
  317.         return NGX_MAIL_PARSE_INVALID_COMMAND;
  318.     }

  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.     }

  326.     ngx_memcpy(s->login.data, arg[0].data, s->login.len);

  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.     }

  334.     ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len);

  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

  345.     return NGX_DONE;
  346. }


  349. static ngx_int_t
  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;

  356. #if (NGX_MAIL_SSL)
  357.     if (ngx_mail_starttls_only(s, c)) {
  358.         return NGX_MAIL_PARSE_INVALID_COMMAND;
  359.     }
  360. #endif

  362.     iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);

  364.     rc = ngx_mail_auth_parse(s, c);

  366.     switch (rc) {

  368.     case NGX_MAIL_AUTH_LOGIN:

  370.         ngx_str_set(&s->out, imap_username);
  371.         s->mail_state = ngx_imap_auth_login_username;

  373.         return NGX_OK;

  375.     case NGX_MAIL_AUTH_LOGIN_USERNAME:

  377.         ngx_str_set(&s->out, imap_password);
  378.         s->mail_state = ngx_imap_auth_login_password;

  380.         return ngx_mail_auth_login_username(s, c, 1);

  382.     case NGX_MAIL_AUTH_PLAIN:

  384.         ngx_str_set(&s->out, imap_plain_next);
  385.         s->mail_state = ngx_imap_auth_plain;

  387.         return NGX_OK;

  389.     case NGX_MAIL_AUTH_CRAM_MD5:

  391.         if (!(iscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
  392.             return NGX_MAIL_PARSE_INVALID_COMMAND;
  393.         }

  395.         if (s->salt.data == NULL) {
  396.             cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);

  398.             if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
  399.                 return NGX_ERROR;
  400.             }
  401.         }

  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.         }

  408.         return NGX_ERROR;

  410.     case NGX_MAIL_AUTH_EXTERNAL:

  412.         if (!(iscf->auth_methods & NGX_MAIL_AUTH_EXTERNAL_ENABLED)) {
  413.             return NGX_MAIL_PARSE_INVALID_COMMAND;
  414.         }

  416.         ngx_str_set(&s->out, imap_username);
  417.         s->mail_state = ngx_imap_auth_external;

  419.         return NGX_OK;
  420.     }

  422.     return rc;
  423. }


  426. static ngx_int_t
  427. ‌ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c)
  428. {
  429.     ngx_mail_imap_srv_conf_t  *iscf;

  431.     iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);

  433. #if (NGX_MAIL_SSL)

  435.     if (c->ssl == NULL) {
  436.         ngx_mail_ssl_conf_t  *sslcf;

  438.         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);

  440.         if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
  441.             s->text = iscf->starttls_capability;
  442.             return NGX_OK;
  443.         }

  445.         if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
  446.             s->text = iscf->starttls_only_capability;
  447.             return NGX_OK;
  448.         }
  449.     }
  450. #endif

  452.     s->text = iscf->capability;

  454.     return NGX_OK;
  455. }


  458. static ngx_int_t
  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;

  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.     }

  474. #endif

  476.     return NGX_MAIL_PARSE_INVALID_COMMAND;
  477. }

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