nginx/src/mail/ngx_mail_imap_handler.c

   1
   2 /*
   3  * Copyright (C) Igor Sysoev
   4  */
   5
   6
   7 #include <ngx_config.h>
   8 #include <ngx_core.h>
   9 #include <ngx_event.h>
  10 #include <ngx_mail.h>
  11 #include <ngx_mail_imap_module.h>
  12
  13
  14 static ngx_int_t ngx_mail_imap_login(ngx_mail_session_t *s,
  15     ngx_connection_t *c);
  16 static ngx_int_t ngx_mail_imap_authenticate(ngx_mail_session_t *s,
  17     ngx_connection_t *c);
  18 static ngx_int_t ngx_mail_imap_capability(ngx_mail_session_t *s,
  19     ngx_connection_t *c);
  20 static ngx_int_t ngx_mail_imap_starttls(ngx_mail_session_t *s,
  21     ngx_connection_t *c);
  22
  23
  24 static u_char  imap_greeting[] = "* OK IMAP4 ready" CRLF;
  25 static u_char  imap_star[] = "* ";
  26 static u_char  imap_ok[] = "OK completed" CRLF;
  27 static u_char  imap_next[] = "+ OK" CRLF;
  28 static u_char  imap_plain_next[] = "+ " CRLF;
  29 static u_char  imap_username[] = "+ VXNlcm5hbWU6" CRLF;
  30 static u_char  imap_password[] = "+ UGFzc3dvcmQ6" CRLF;
  31 static u_char  imap_bye[] = "* BYE" CRLF;
  32 static u_char  imap_invalid_command[] = "BAD invalid command" CRLF;
  33
  34
  35 void
  36 ngx_mail_imap_init_session(ngx_mail_session_t *s, ngx_connection_t *c)
  37 {
  38     ngx_mail_core_srv_conf_t  *cscf;
  39
  40     cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
  41
  42     s->out.len = sizeof(imap_greeting) - 1;
  43     s->out.data = 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
  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
 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         return;
 127     }
 128
 129     s->blocked = 0;
 130
 131     rc = ngx_mail_read_command(s, c);
 132
 133     if (rc == NGX_AGAIN || rc == NGX_ERROR) {
 134         return;
 135     }
 136
 137     tag = 1;
 138     s->text.len = 0;
 139     s->out.len = sizeof(imap_ok) - 1;
 140     s->out.data = imap_ok;
 141
 142     if (rc == NGX_OK) {
 143
 144         ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "imap auth command: %i",
 145                        s->command);
 146
 147         if (s->backslash) {
 148
 149             arg = s->args.elts;
 150
 151             for (i = 0; i < s->args.nelts; i++) {
 152                 dst = arg[i].data;
 153                 end = dst + arg[i].len;
 154
 155                 for (src = dst; src < end; dst++) {
 156                     *dst = *src;
 157                     if (*src++ == '\\') {
 158                         *dst = *src++;
 159                     }
 160                 }
 161
 162                 arg[i].len = dst - arg[i].data;
 163             }
 164
 165             s->backslash = 0;
 166         }
 167
 168         switch (s->mail_state) {
 169
 170         case ngx_imap_start:
 171
 172             switch (s->command) {
 173
 174             case NGX_IMAP_LOGIN:
 175                 rc = ngx_mail_imap_login(s, c);
 176                 break;
 177
 178             case NGX_IMAP_AUTHENTICATE:
 179                 rc = ngx_mail_imap_authenticate(s, c);
 180                 tag = (rc != NGX_OK);
 181                 break;
 182
 183             case NGX_IMAP_CAPABILITY:
 184                 rc = ngx_mail_imap_capability(s, c);
 185                 break;
 186
 187             case NGX_IMAP_LOGOUT:
 188                 s->quit = 1;
 189                 s->text.len = sizeof(imap_bye) - 1;
 190                 s->text.data = imap_bye;
 191                 break;
 192
 193             case NGX_IMAP_NOOP:
 194                 break;
 195
 196             case NGX_IMAP_STARTTLS:
 197                 rc = ngx_mail_imap_starttls(s, c);
 198                 break;
 199
 200             default:
 201                 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
 202                 break;
 203             }
 204
 205             break;
 206
 207         case ngx_imap_auth_login_username:
 208             rc = ngx_mail_auth_login_username(s, c, 0);
 209
 210             tag = 0;
 211             s->out.len = sizeof(imap_password) - 1;
 212             s->out.data = imap_password;
 213             s->mail_state = ngx_imap_auth_login_password;
 214
 215             break;
 216
 217         case ngx_imap_auth_login_password:
 218             rc = ngx_mail_auth_login_password(s, c);
 219             break;
 220
 221         case ngx_imap_auth_plain:
 222             rc = ngx_mail_auth_plain(s, c, 0);
 223             break;
 224
 225         case ngx_imap_auth_cram_md5:
 226             rc = ngx_mail_auth_cram_md5(s, c);
 227             break;
 228         }
 229
 230     } else if (rc == NGX_IMAP_NEXT) {
 231         tag = 0;
 232         s->out.len = sizeof(imap_next) - 1;
 233         s->out.data = imap_next;
 234     }
 235
 236     switch (rc) {
 237
 238     case NGX_DONE:
 239         ngx_mail_auth(s, c);
 240         return;
 241
 242     case NGX_ERROR:
 243         ngx_mail_session_internal_server_error(s);
 244         return;
 245
 246     case NGX_MAIL_PARSE_INVALID_COMMAND:
 247         s->state = 0;
 248         s->out.len = sizeof(imap_invalid_command) - 1;
 249         s->out.data = imap_invalid_command;
 250         s->mail_state = ngx_imap_start;
 251         break;
 252     }
 253
 254     if (tag) {
 255         if (s->tag.len == 0) {
 256             s->tag.len = sizeof(imap_star) - 1;
 257             s->tag.data = (u_char *) imap_star;
 258         }
 259
 260         if (s->tagged_line.len < s->tag.len + s->text.len + s->out.len) {
 261             s->tagged_line.len = s->tag.len + s->text.len + s->out.len;
 262             s->tagged_line.data = ngx_pnalloc(c->pool, s->tagged_line.len);
 263             if (s->tagged_line.data == NULL) {
 264                 ngx_mail_close_connection(c);
 265                 return;
 266             }
 267         }
 268
 269         p = s->tagged_line.data;
 270
 271         if (s->text.len) {
 272             p = ngx_cpymem(p, s->text.data, s->text.len);
 273         }
 274
 275         p = ngx_cpymem(p, s->tag.data, s->tag.len);
 276         ngx_memcpy(p, s->out.data, s->out.len);
 277
 278         s->out.len = s->text.len + s->tag.len + s->out.len;
 279         s->out.data = s->tagged_line.data;
 280     }
 281
 282     if (rc != NGX_IMAP_NEXT) {
 283         s->args.nelts = 0;
 284
 285         if (s->state) {
 286             /* preserve tag */
 287             s->arg_start = s->buffer->start + s->tag.len;
 288             s->buffer->pos = s->arg_start;
 289             s->buffer->last = s->arg_start;
 290
 291         } else {
 292             s->buffer->pos = s->buffer->start;
 293             s->buffer->last = s->buffer->start;
 294             s->tag.len = 0;
 295         }
 296     }
 297
 298     ngx_mail_send(c->write);
 299 }
 300
 301
 302 static ngx_int_t
 303 ngx_mail_imap_login(ngx_mail_session_t *s, ngx_connection_t *c)
 304 {
 305     ngx_str_t  *arg;
 306
 307 #if (NGX_MAIL_SSL)
 308     if (ngx_mail_starttls_only(s, c)) {
 309         return NGX_MAIL_PARSE_INVALID_COMMAND;
 310     }
 311 #endif
 312
 313     arg = s->args.elts;
 314
 315     if (s->args.nelts != 2 || arg[0].len == 0) {
 316         return NGX_MAIL_PARSE_INVALID_COMMAND;
 317     }
 318
 319     s->login.len = arg[0].len;
 320     s->login.data = ngx_pnalloc(c->pool, s->login.len);
 321     if (s->login.data == NULL) {
 322         return NGX_ERROR;
 323     }
 324
 325     ngx_memcpy(s->login.data, arg[0].data, s->login.len);
 326
 327     s->passwd.len = arg[1].len;
 328     s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
 329     if (s->passwd.data == NULL) {
 330         return NGX_ERROR;
 331     }
 332
 333     ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len);
 334
 335 #if (NGX_DEBUG_MAIL_PASSWD)
 336     ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
 337                    "imap login:\"%V\" passwd:\"%V\"",
 338                    &s->login, &s->passwd);
 339 #else
 340     ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
 341                    "imap login:\"%V\"", &s->login);
 342 #endif
 343
 344     return NGX_DONE;
 345 }
 346
 347
 348 static ngx_int_t
 349 ngx_mail_imap_authenticate(ngx_mail_session_t *s, ngx_connection_t *c)
 350 {
 351     ngx_int_t                  rc;
 352     ngx_mail_core_srv_conf_t  *cscf;
 353     ngx_mail_imap_srv_conf_t  *iscf;
 354
 355 #if (NGX_MAIL_SSL)
 356     if (ngx_mail_starttls_only(s, c)) {
 357         return NGX_MAIL_PARSE_INVALID_COMMAND;
 358     }
 359 #endif
 360
 361     rc = ngx_mail_auth_parse(s, c);
 362
 363     switch (rc) {
 364
 365     case NGX_MAIL_AUTH_LOGIN:
 366
 367         s->out.len = sizeof(imap_username) - 1;
 368         s->out.data = imap_username;
 369         s->mail_state = ngx_imap_auth_login_username;
 370
 371         return NGX_OK;
 372
 373     case NGX_MAIL_AUTH_LOGIN_USERNAME:
 374
 375         s->out.len = sizeof(imap_password) - 1;
 376         s->out.data = imap_password;
 377         s->mail_state = ngx_imap_auth_login_password;
 378
 379         return ngx_mail_auth_login_username(s, c, 1);
 380
 381     case NGX_MAIL_AUTH_PLAIN:
 382
 383         s->out.len = sizeof(imap_plain_next) - 1;
 384         s->out.data = 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         iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
 392
 393         if (!(iscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
 394             return NGX_MAIL_PARSE_INVALID_COMMAND;
 395         }
 396
 397         if (s->salt.data == NULL) {
 398             cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
 399
 400             if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
 401                 return NGX_ERROR;
 402             }
 403         }
 404
 405         if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) {
 406             s->mail_state = ngx_imap_auth_cram_md5;
 407             return NGX_OK;
 408         }
 409
 410         return NGX_ERROR;
 411     }
 412
 413     return rc;
 414 }
 415
 416
 417 static ngx_int_t
 418 ngx_mail_imap_capability(ngx_mail_session_t *s, ngx_connection_t *c)
 419 {
 420     ngx_mail_imap_srv_conf_t  *iscf;
 421
 422     iscf = ngx_mail_get_module_srv_conf(s, ngx_mail_imap_module);
 423
 424 #if (NGX_MAIL_SSL)
 425
 426     if (c->ssl == NULL) {
 427         ngx_mail_ssl_conf_t  *sslcf;
 428
 429         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
 430
 431         if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
 432             s->text = iscf->starttls_capability;
 433             return NGX_OK;
 434         }
 435
 436         if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
 437             s->text = iscf->starttls_only_capability;
 438             return NGX_OK;
 439         }
 440     }
 441 #endif
 442
 443     s->text = iscf->capability;
 444
 445     return NGX_OK;
 446 }
 447
 448
 449 static ngx_int_t
 450 ngx_mail_imap_starttls(ngx_mail_session_t *s, ngx_connection_t *c)
 451 {
 452 #if (NGX_MAIL_SSL)
 453     ngx_mail_ssl_conf_t  *sslcf;
 454
 455     if (c->ssl == NULL) {
 456         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
 457         if (sslcf->starttls) {
 458             c->read->handler = ngx_mail_starttls_handler;
 459             return NGX_OK;
 460         }
 461     }
 462
 463 #endif
 464
 465     return NGX_MAIL_PARSE_INVALID_COMMAND;
 466 }