src/mail/ngx_mail_imap_handler.c - nginx-1.7.10

Global variables defined

Functions defined

Source code


  1. /*
  2. * Copyright (C) Igor Sysoev
  3. * Copyright (C) Nginx, Inc.
  4. */


  5. #include <ngx_config.h>
  6. #include <ngx_core.h>
  7. #include <ngx_event.h>
  8. #include <ngx_mail.h>
  9. #include <ngx_mail_imap_module.h>


  10. static ngx_int_t ngx_mail_imap_login(ngx_mail_session_t *s,
  11.     ngx_connection_t *c);
  12. static ngx_int_t ngx_mail_imap_authenticate(ngx_mail_session_t *s,
  13.     ngx_connection_t *c);
  14. static ngx_int_t ngx_mail_imap_capability(ngx_mail_session_t *s,
  15.     ngx_connection_t *c);
  16. static ngx_int_t ngx_mail_imap_starttls(ngx_mail_session_t *s,
  17.     ngx_connection_t *c);


  18. static u_char  imap_greeting[] = "* OK IMAP4 ready" CRLF;
  19. static u_char  imap_star[] = "* ";
  20. static u_char  imap_ok[] = "OK completed" CRLF;
  21. static u_char  imap_next[] = "+ OK" CRLF;
  22. static u_char  imap_plain_next[] = "+ " CRLF;
  23. static u_char  imap_username[] = "+ VXNlcm5hbWU6" CRLF;
  24. static u_char  imap_password[] = "+ UGFzc3dvcmQ6" CRLF;
  25. static u_char  imap_bye[] = "* BYE" CRLF;
  26. static u_char  imap_invalid_command[] = "BAD invalid command" CRLF;


  27. void
  28. ngx_mail_imap_init_session(ngx_mail_session_t *s, ngx_connection_t *c)
  29. {
  30.     ngx_mail_core_srv_conf_t  *cscf;

  31.     cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);

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

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

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

  35.     if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
  36.         ngx_mail_close_connection(c);
  37.     }

  38.     ngx_mail_send(c->write);
  39. }


  40. void
  41. ngx_mail_imap_init_protocol(ngx_event_t *rev)
  42. {
  43.     ngx_connection_t          *c;
  44.     ngx_mail_session_t        *s;
  45.     ngx_mail_imap_srv_conf_t  *iscf;

  46.     c = rev->data;

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

  48.     if (rev->timedout) {
  49.         ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
  50.         c->timedout = 1;
  51.         ngx_mail_close_connection(c);
  52.         return;
  53.     }

  54.     s = c->data;

  55.     if (s->buffer == NULL) {
  56.         if (ngx_array_init(&s->args, c->pool, 2, sizeof(ngx_str_t))
  57.             == NGX_ERROR)
  58.         {
  59.             ngx_mail_session_internal_server_error(s);
  60.             return;
  61.         }

  62.         iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);

  63.         s->buffer = ngx_create_temp_buf(c->pool, iscf->client_buffer_size);
  64.         if (s->buffer == NULL) {
  65.             ngx_mail_session_internal_server_error(s);
  66.             return;
  67.         }
  68.     }

  69.     s->mail_state = ngx_imap_start;
  70.     c->read->handler = ngx_mail_imap_auth_state;

  71.     ngx_mail_imap_auth_state(rev);
  72. }


  73. void
  74. ngx_mail_imap_auth_state(ngx_event_t *rev)
  75. {
  76.     u_char              *p, *dst, *src, *end;
  77.     ngx_str_t           *arg;
  78.     ngx_int_t            rc;
  79.     ngx_uint_t           tag, i;
  80.     ngx_connection_t    *c;
  81.     ngx_mail_session_t  *s;

  82.     c = rev->data;
  83.     s = c->data;

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

  85.     if (rev->timedout) {
  86.         ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
  87.         c->timedout = 1;
  88.         ngx_mail_close_connection(c);
  89.         return;
  90.     }

  91.     if (s->out.len) {
  92.         ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap send handler busy");
  93.         s->blocked = 1;
  94.         return;
  95.     }

  96.     s->blocked = 0;

  97.     rc = ngx_mail_read_command(s, c);

  98.     if (rc == NGX_AGAIN || rc == NGX_ERROR) {
  99.         return;
  100.     }

  101.     tag = 1;
  102.     s->text.len = 0;
  103.     ngx_str_set(&s->out, imap_ok);

  104.     if (rc == NGX_OK) {

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

  107.         if (s->backslash) {

  108.             arg = s->args.elts;

  109.             for (i = 0; i < s->args.nelts; i++) {
  110.                 dst = arg[i].data;
  111.                 end = dst + arg[i].len;

  112.                 for (src = dst; src < end; dst++) {
  113.                     *dst = *src;
  114.                     if (*src++ == '\\') {
  115.                         *dst = *src++;
  116.                     }
  117.                 }

  118.                 arg[i].len = dst - arg[i].data;
  119.             }

  120.             s->backslash = 0;
  121.         }

  122.         switch (s->mail_state) {

  123.         case ngx_imap_start:

  124.             switch (s->command) {

  125.             case NGX_IMAP_LOGIN:
  126.                 rc = ngx_mail_imap_login(s, c);
  127.                 break;

  128.             case NGX_IMAP_AUTHENTICATE:
  129.                 rc = ngx_mail_imap_authenticate(s, c);
  130.                 tag = (rc != NGX_OK);
  131.                 break;

  132.             case NGX_IMAP_CAPABILITY:
  133.                 rc = ngx_mail_imap_capability(s, c);
  134.                 break;

  135.             case NGX_IMAP_LOGOUT:
  136.                 s->quit = 1;
  137.                 ngx_str_set(&s->text, imap_bye);
  138.                 break;

  139.             case NGX_IMAP_NOOP:
  140.                 break;

  141.             case NGX_IMAP_STARTTLS:
  142.                 rc = ngx_mail_imap_starttls(s, c);
  143.                 break;

  144.             default:
  145.                 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
  146.                 break;
  147.             }

  148.             break;

  149.         case ngx_imap_auth_login_username:
  150.             rc = ngx_mail_auth_login_username(s, c, 0);

  151.             tag = 0;
  152.             ngx_str_set(&s->out, imap_password);
  153.             s->mail_state = ngx_imap_auth_login_password;

  154.             break;

  155.         case ngx_imap_auth_login_password:
  156.             rc = ngx_mail_auth_login_password(s, c);
  157.             break;

  158.         case ngx_imap_auth_plain:
  159.             rc = ngx_mail_auth_plain(s, c, 0);
  160.             break;

  161.         case ngx_imap_auth_cram_md5:
  162.             rc = ngx_mail_auth_cram_md5(s, c);
  163.             break;
  164.         }

  165.     } else if (rc == NGX_IMAP_NEXT) {
  166.         tag = 0;
  167.         ngx_str_set(&s->out, imap_next);
  168.     }

  169.     switch (rc) {

  170.     case NGX_DONE:
  171.         ngx_mail_auth(s, c);
  172.         return;

  173.     case NGX_ERROR:
  174.         ngx_mail_session_internal_server_error(s);
  175.         return;

  176.     case NGX_MAIL_PARSE_INVALID_COMMAND:
  177.         s->state = 0;
  178.         ngx_str_set(&s->out, imap_invalid_command);
  179.         s->mail_state = ngx_imap_start;
  180.         break;
  181.     }

  182.     if (tag) {
  183.         if (s->tag.len == 0) {
  184.             ngx_str_set(&s->tag, imap_star);
  185.         }

  186.         if (s->tagged_line.len < s->tag.len + s->text.len + s->out.len) {
  187.             s->tagged_line.len = s->tag.len + s->text.len + s->out.len;
  188.             s->tagged_line.data = ngx_pnalloc(c->pool, s->tagged_line.len);
  189.             if (s->tagged_line.data == NULL) {
  190.                 ngx_mail_close_connection(c);
  191.                 return;
  192.             }
  193.         }

  194.         p = s->tagged_line.data;

  195.         if (s->text.len) {
  196.             p = ngx_cpymem(p, s->text.data, s->text.len);
  197.         }

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

  200.         s->out.len = s->text.len + s->tag.len + s->out.len;
  201.         s->out.data = s->tagged_line.data;
  202.     }

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

  205.         if (s->state) {
  206.             /* preserve tag */
  207.             s->arg_start = s->buffer->start + s->tag.len;
  208.             s->buffer->pos = s->arg_start;
  209.             s->buffer->last = s->arg_start;

  210.         } else {
  211.             s->buffer->pos = s->buffer->start;
  212.             s->buffer->last = s->buffer->start;
  213.             s->tag.len = 0;
  214.         }
  215.     }

  216.     ngx_mail_send(c->write);
  217. }


  218. static ngx_int_t
  219. ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c)
  220. {
  221.     ngx_str_t  *arg;

  222. #if (NGX_MAIL_SSL)
  223.     if (ngx_mail_starttls_only(s, c)) {
  224.         return NGX_MAIL_PARSE_INVALID_COMMAND;
  225.     }
  226. #endif

  227.     arg = s->args.elts;

  228.     if (s->args.nelts != 2 || arg[0].len == 0) {
  229.         return NGX_MAIL_PARSE_INVALID_COMMAND;
  230.     }

  231.     s->login.len = arg[0].len;
  232.     s->login.data = ngx_pnalloc(c->pool, s->login.len);
  233.     if (s->login.data == NULL) {
  234.         return NGX_ERROR;
  235.     }

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

  237.     s->passwd.len = arg[1].len;
  238.     s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
  239.     if (s->passwd.data == NULL) {
  240.         return NGX_ERROR;
  241.     }

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

  243. #if (NGX_DEBUG_MAIL_PASSWD)
  244.     ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
  245.                    "imap login:\"%V\" passwd:\"%V\"",
  246.                    &s->login, &s->passwd);
  247. #else
  248.     ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
  249.                    "imap login:\"%V\"", &s->login);
  250. #endif

  251.     return NGX_DONE;
  252. }


  253. static ngx_int_t
  254. ngx_mail_imap_authenticate(ngx_mail_session_t *s, ngx_connection_t *c)
  255. {
  256.     ngx_int_t                  rc;
  257.     ngx_mail_core_srv_conf_t  *cscf;
  258.     ngx_mail_imap_srv_conf_t  *iscf;

  259. #if (NGX_MAIL_SSL)
  260.     if (ngx_mail_starttls_only(s, c)) {
  261.         return NGX_MAIL_PARSE_INVALID_COMMAND;
  262.     }
  263. #endif

  264.     rc = ngx_mail_auth_parse(s, c);

  265.     switch (rc) {

  266.     case NGX_MAIL_AUTH_LOGIN:

  267.         ngx_str_set(&s->out, imap_username);
  268.         s->mail_state = ngx_imap_auth_login_username;

  269.         return NGX_OK;

  270.     case NGX_MAIL_AUTH_LOGIN_USERNAME:

  271.         ngx_str_set(&s->out, imap_password);
  272.         s->mail_state = ngx_imap_auth_login_password;

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

  274.     case NGX_MAIL_AUTH_PLAIN:

  275.         ngx_str_set(&s->out, imap_plain_next);
  276.         s->mail_state = ngx_imap_auth_plain;

  277.         return NGX_OK;

  278.     case NGX_MAIL_AUTH_CRAM_MD5:

  279.         iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);

  280.         if (!(iscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
  281.             return NGX_MAIL_PARSE_INVALID_COMMAND;
  282.         }

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

  285.             if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
  286.                 return NGX_ERROR;
  287.             }
  288.         }

  289.         if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) {
  290.             s->mail_state = ngx_imap_auth_cram_md5;
  291.             return NGX_OK;
  292.         }

  293.         return NGX_ERROR;
  294.     }

  295.     return rc;
  296. }


  297. static ngx_int_t
  298. ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c)
  299. {
  300.     ngx_mail_imap_srv_conf_t  *iscf;

  301.     iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);

  302. #if (NGX_MAIL_SSL)

  303.     if (c->ssl == NULL) {
  304.         ngx_mail_ssl_conf_t  *sslcf;

  305.         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);

  306.         if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
  307.             s->text = iscf->starttls_capability;
  308.             return NGX_OK;
  309.         }

  310.         if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
  311.             s->text = iscf->starttls_only_capability;
  312.             return NGX_OK;
  313.         }
  314.     }
  315. #endif

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

  317.     return NGX_OK;
  318. }


  319. static ngx_int_t
  320. ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c)
  321. {
  322. #if (NGX_MAIL_SSL)
  323.     ngx_mail_ssl_conf_t  *sslcf;

  324.     if (c->ssl == NULL) {
  325.         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
  326.         if (sslcf->starttls) {
  327.             c->read->handler = ngx_mail_starttls_handler;
  328.             return NGX_OK;
  329.         }
  330.     }

  331. #endif

  332.     return NGX_MAIL_PARSE_INVALID_COMMAND;
  333. }