nginx/src/mail/ngx_mail_pop3_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_pop3_module.h>
  12
  13
  14 static ngx_int_t ngx_mail_pop3_user(ngx_mail_session_t *s, ngx_connection_t *c);
  15 static ngx_int_t ngx_mail_pop3_pass(ngx_mail_session_t *s, ngx_connection_t *c);
  16 static ngx_int_t ngx_mail_pop3_capa(ngx_mail_session_t *s, ngx_connection_t *c,
  17     ngx_int_t stls);
  18 static ngx_int_t ngx_mail_pop3_stls(ngx_mail_session_t *s, ngx_connection_t *c);
  19 static ngx_int_t ngx_mail_pop3_apop(ngx_mail_session_t *s, ngx_connection_t *c);
  20 static ngx_int_t ngx_mail_pop3_auth(ngx_mail_session_t *s, ngx_connection_t *c);
  21
  22
  23 static u_char  pop3_greeting[] = "+OK POP3 ready" CRLF;
  24 static u_char  pop3_ok[] = "+OK" CRLF;
  25 static u_char  pop3_next[] = "+ " CRLF;
  26 static u_char  pop3_username[] = "+ VXNlcm5hbWU6" CRLF;
  27 static u_char  pop3_password[] = "+ UGFzc3dvcmQ6" CRLF;
  28 static u_char  pop3_invalid_command[] = "-ERR invalid command" CRLF;
  29
  30
  31 void
  32 ngx_mail_pop3_init_session(ngx_mail_session_t *s, ngx_connection_t *c)
  33 {
  34     u_char                    *p;
  35     ngx_mail_core_srv_conf_t  *cscf;
  36     ngx_mail_pop3_srv_conf_t  *pscf;
  37
  38     pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
  39     cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module);
  40
  41     if (pscf->auth_methods
  42         & (NGX_MAIL_AUTH_APOP_ENABLED|NGX_MAIL_AUTH_CRAM_MD5_ENABLED))
  43     {
  44         if (ngx_mail_salt(s, c, cscf) != NGX_OK) {
  45             ngx_mail_session_internal_server_error(s);
  46             return;
  47         }
  48
  49         s->out.data = ngx_pnalloc(c->pool, sizeof(pop3_greeting) + s->salt.len);
  50         if (s->out.data == NULL) {
  51             ngx_mail_session_internal_server_error(s);
  52             return;
  53         }
  54
  55         p = ngx_cpymem(s->out.data, pop3_greeting, sizeof(pop3_greeting) - 3);
  56         *p++ = ' ';
  57         p = ngx_cpymem(p, s->salt.data, s->salt.len);
  58
  59         s->out.len = p - s->out.data;
  60
  61     } else {
  62         s->out.len = sizeof(pop3_greeting) - 1;
  63         s->out.data = pop3_greeting;
  64     }
  65
  66     c->read->handler = ngx_mail_pop3_init_protocol;
  67
  68     ngx_add_timer(c->read, cscf->timeout);
  69
  70     if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
  71         ngx_mail_close_connection(c);
  72     }
  73
  74     ngx_mail_send(c->write);
  75 }
  76
  77
  78 void
  79 ngx_mail_pop3_init_protocol(ngx_event_t *rev)
  80 {
  81     ngx_connection_t    *c;
  82     ngx_mail_session_t  *s;
  83
  84     c = rev->data;
  85
  86     c->log->action = "in auth state";
  87
  88     if (rev->timedout) {
  89         ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
  90         c->timedout = 1;
  91         ngx_mail_close_connection(c);
  92         return;
  93     }
  94
  95     s = c->data;
  96
  97     if (s->buffer == NULL) {
  98         if (ngx_array_init(&s->args, c->pool, 2, sizeof(ngx_str_t))
  99             == NGX_ERROR)
 100         {
 101             ngx_mail_session_internal_server_error(s);
 102             return;
 103         }
 104
 105         s->buffer = ngx_create_temp_buf(c->pool, 128);
 106         if (s->buffer == NULL) {
 107             ngx_mail_session_internal_server_error(s);
 108             return;
 109         }
 110     }
 111
 112     s->mail_state = ngx_pop3_start;
 113     c->read->handler = ngx_mail_pop3_auth_state;
 114
 115     ngx_mail_pop3_auth_state(rev);
 116 }
 117
 118
 119 void
 120 ngx_mail_pop3_auth_state(ngx_event_t *rev)
 121 {
 122     ngx_int_t            rc;
 123     ngx_connection_t    *c;
 124     ngx_mail_session_t  *s;
 125
 126     c = rev->data;
 127     s = c->data;
 128
 129     ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "pop3 auth state");
 130
 131     if (rev->timedout) {
 132         ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
 133         c->timedout = 1;
 134         ngx_mail_close_connection(c);
 135         return;
 136     }
 137
 138     if (s->out.len) {
 139         ngx_log_debug0(NGX_LOG_DEBUG_MAIL, c->log, 0, "pop3 send handler busy");
 140         s->blocked = 1;
 141         return;
 142     }
 143
 144     s->blocked = 0;
 145
 146     rc = ngx_mail_read_command(s, c);
 147
 148     if (rc == NGX_AGAIN || rc == NGX_ERROR) {
 149         return;
 150     }
 151
 152     s->out.len = sizeof(pop3_ok) - 1;
 153     s->out.data = pop3_ok;
 154
 155     if (rc == NGX_OK) {
 156         switch (s->mail_state) {
 157
 158         case ngx_pop3_start:
 159
 160             switch (s->command) {
 161
 162             case NGX_POP3_USER:
 163                 rc = ngx_mail_pop3_user(s, c);
 164                 break;
 165
 166             case NGX_POP3_CAPA:
 167                 rc = ngx_mail_pop3_capa(s, c, 1);
 168                 break;
 169
 170             case NGX_POP3_APOP:
 171                 rc = ngx_mail_pop3_apop(s, c);
 172                 break;
 173
 174             case NGX_POP3_AUTH:
 175                 rc = ngx_mail_pop3_auth(s, c);
 176                 break;
 177
 178             case NGX_POP3_QUIT:
 179                 s->quit = 1;
 180                 break;
 181
 182             case NGX_POP3_NOOP:
 183                 break;
 184
 185             case NGX_POP3_STLS:
 186                 rc = ngx_mail_pop3_stls(s, c);
 187                 break;
 188
 189             default:
 190                 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
 191                 s->mail_state = ngx_pop3_start;
 192                 break;
 193             }
 194
 195             break;
 196
 197         case ngx_pop3_user:
 198
 199             switch (s->command) {
 200
 201             case NGX_POP3_PASS:
 202                 rc = ngx_mail_pop3_pass(s, c);
 203                 break;
 204
 205             case NGX_POP3_CAPA:
 206                 rc = ngx_mail_pop3_capa(s, c, 0);
 207                 break;
 208
 209             case NGX_POP3_QUIT:
 210                 s->quit = 1;
 211                 break;
 212
 213             case NGX_POP3_NOOP:
 214                 break;
 215
 216             default:
 217                 rc = NGX_MAIL_PARSE_INVALID_COMMAND;
 218                 s->mail_state = ngx_pop3_start;
 219                 break;
 220             }
 221
 222             break;
 223
 224         /* suppress warinings */
 225         case ngx_pop3_passwd:
 226             break;
 227
 228         case ngx_pop3_auth_login_username:
 229             rc = ngx_mail_auth_login_username(s, c, 0);
 230
 231             s->out.len = sizeof(pop3_password) - 1;
 232             s->out.data = pop3_password;
 233             s->mail_state = ngx_pop3_auth_login_password;
 234             break;
 235
 236         case ngx_pop3_auth_login_password:
 237             rc = ngx_mail_auth_login_password(s, c);
 238             break;
 239
 240         case ngx_pop3_auth_plain:
 241             rc = ngx_mail_auth_plain(s, c, 0);
 242             break;
 243
 244         case ngx_pop3_auth_cram_md5:
 245             rc = ngx_mail_auth_cram_md5(s, c);
 246             break;
 247         }
 248     }
 249
 250     switch (rc) {
 251
 252     case NGX_DONE:
 253         ngx_mail_auth(s, c);
 254         return;
 255
 256     case NGX_ERROR:
 257         ngx_mail_session_internal_server_error(s);
 258         return;
 259
 260     case NGX_MAIL_PARSE_INVALID_COMMAND:
 261         s->mail_state = ngx_pop3_start;
 262         s->state = 0;
 263
 264         s->out.len = sizeof(pop3_invalid_command) - 1;
 265         s->out.data = pop3_invalid_command;
 266
 267         /* fall through */
 268
 269     case NGX_OK:
 270
 271         s->args.nelts = 0;
 272         s->buffer->pos = s->buffer->start;
 273         s->buffer->last = s->buffer->start;
 274
 275         if (s->state) {
 276             s->arg_start = s->buffer->start;
 277         }
 278
 279         ngx_mail_send(c->write);
 280     }
 281 }
 282
 283 static ngx_int_t
 284 ngx_mail_pop3_user(ngx_mail_session_t *s, ngx_connection_t *c)
 285 {
 286     ngx_str_t  *arg;
 287
 288 #if (NGX_MAIL_SSL)
 289     if (ngx_mail_starttls_only(s, c)) {
 290         return NGX_MAIL_PARSE_INVALID_COMMAND;
 291     }
 292 #endif
 293
 294     if (s->args.nelts != 1) {
 295         return NGX_MAIL_PARSE_INVALID_COMMAND;
 296     }
 297
 298     arg = s->args.elts;
 299     s->login.len = arg[0].len;
 300     s->login.data = ngx_pnalloc(c->pool, s->login.len);
 301     if (s->login.data == NULL) {
 302         return NGX_ERROR;
 303     }
 304
 305     ngx_memcpy(s->login.data, arg[0].data, s->login.len);
 306
 307     ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
 308                    "pop3 login: \"%V\"", &s->login);
 309
 310     s->mail_state = ngx_pop3_user;
 311
 312     return NGX_OK;
 313 }
 314
 315
 316 static ngx_int_t
 317 ngx_mail_pop3_pass(ngx_mail_session_t *s, ngx_connection_t *c)
 318 {
 319     ngx_str_t  *arg;
 320
 321     if (s->args.nelts != 1) {
 322         return NGX_MAIL_PARSE_INVALID_COMMAND;
 323     }
 324
 325     arg = s->args.elts;
 326     s->passwd.len = arg[0].len;
 327     s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
 328     if (s->passwd.data == NULL) {
 329         return NGX_ERROR;
 330     }
 331
 332     ngx_memcpy(s->passwd.data, arg[0].data, s->passwd.len);
 333
 334 #if (NGX_DEBUG_MAIL_PASSWD)
 335     ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0,
 336                    "pop3 passwd: \"%V\"", &s->passwd);
 337 #endif
 338
 339     return NGX_DONE;
 340 }
 341
 342
 343 static ngx_int_t
 344 ngx_mail_pop3_capa(ngx_mail_session_t *s, ngx_connection_t *c, ngx_int_t stls)
 345 {
 346     ngx_mail_pop3_srv_conf_t  *pscf;
 347
 348     pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
 349
 350 #if (NGX_MAIL_SSL)
 351
 352     if (stls && c->ssl == NULL) {
 353         ngx_mail_ssl_conf_t  *sslcf;
 354
 355         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
 356
 357         if (sslcf->starttls == NGX_MAIL_STARTTLS_ON) {
 358             s->out = pscf->starttls_capability;
 359             return NGX_OK;
 360         }
 361
 362         if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) {
 363             s->out = pscf->starttls_only_capability;
 364             return NGX_OK;
 365         }
 366     }
 367
 368 #endif
 369
 370     s->out = pscf->capability;
 371     return NGX_OK;
 372 }
 373
 374
 375 static ngx_int_t
 376 ngx_mail_pop3_stls(ngx_mail_session_t *s, ngx_connection_t *c)
 377 {
 378 #if (NGX_MAIL_SSL)
 379     ngx_mail_ssl_conf_t  *sslcf;
 380
 381     if (c->ssl == NULL) {
 382         sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module);
 383         if (sslcf->starttls) {
 384             c->read->handler = ngx_mail_starttls_handler;
 385             return NGX_OK;
 386         }
 387     }
 388
 389 #endif
 390
 391     return NGX_MAIL_PARSE_INVALID_COMMAND;
 392 }
 393
 394
 395 static ngx_int_t
 396 ngx_mail_pop3_apop(ngx_mail_session_t *s, ngx_connection_t *c)
 397 {
 398     ngx_str_t                 *arg;
 399     ngx_mail_pop3_srv_conf_t  *pscf;
 400
 401 #if (NGX_MAIL_SSL)
 402     if (ngx_mail_starttls_only(s, c)) {
 403         return NGX_MAIL_PARSE_INVALID_COMMAND;
 404     }
 405 #endif
 406
 407     if (s->args.nelts != 2) {
 408         return NGX_MAIL_PARSE_INVALID_COMMAND;
 409     }
 410
 411     pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
 412
 413     if (!(pscf->auth_methods & NGX_MAIL_AUTH_APOP_ENABLED)) {
 414         return NGX_MAIL_PARSE_INVALID_COMMAND;
 415     }
 416
 417     arg = s->args.elts;
 418
 419     s->login.len = arg[0].len;
 420     s->login.data = ngx_pnalloc(c->pool, s->login.len);
 421     if (s->login.data == NULL) {
 422         return NGX_ERROR;
 423     }
 424
 425     ngx_memcpy(s->login.data, arg[0].data, s->login.len);
 426
 427     s->passwd.len = arg[1].len;
 428     s->passwd.data = ngx_pnalloc(c->pool, s->passwd.len);
 429     if (s->passwd.data == NULL) {
 430         return NGX_ERROR;
 431     }
 432
 433     ngx_memcpy(s->passwd.data, arg[1].data, s->passwd.len);
 434
 435     ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0,
 436                    "pop3 apop: \"%V\" \"%V\"", &s->login, &s->passwd);
 437
 438     s->auth_method = NGX_MAIL_AUTH_APOP;
 439
 440     return NGX_DONE;
 441 }
 442
 443
 444 static ngx_int_t
 445 ngx_mail_pop3_auth(ngx_mail_session_t *s, ngx_connection_t *c)
 446 {
 447     ngx_int_t                  rc;
 448     ngx_mail_pop3_srv_conf_t  *pscf;
 449
 450 #if (NGX_MAIL_SSL)
 451     if (ngx_mail_starttls_only(s, c)) {
 452         return NGX_MAIL_PARSE_INVALID_COMMAND;
 453     }
 454 #endif
 455
 456     pscf = ngx_mail_get_module_srv_conf(s, ngx_mail_pop3_module);
 457
 458     if (s->args.nelts == 0) {
 459         s->out = pscf->auth_capability;
 460         s->state = 0;
 461
 462         return NGX_OK;
 463     }
 464
 465     rc = ngx_mail_auth_parse(s, c);
 466
 467     switch (rc) {
 468
 469     case NGX_MAIL_AUTH_LOGIN:
 470
 471         s->out.len = sizeof(pop3_username) - 1;
 472         s->out.data = pop3_username;
 473         s->mail_state = ngx_pop3_auth_login_username;
 474
 475         return NGX_OK;
 476
 477     case NGX_MAIL_AUTH_LOGIN_USERNAME:
 478
 479         s->out.len = sizeof(pop3_password) - 1;
 480         s->out.data = pop3_password;
 481         s->mail_state = ngx_pop3_auth_login_password;
 482
 483         return ngx_mail_auth_login_username(s, c, 1);
 484
 485     case NGX_MAIL_AUTH_PLAIN:
 486
 487         s->out.len = sizeof(pop3_next) - 1;
 488         s->out.data = pop3_next;
 489         s->mail_state = ngx_pop3_auth_plain;
 490
 491         return NGX_OK;
 492
 493     case NGX_MAIL_AUTH_CRAM_MD5:
 494
 495         if (!(pscf->auth_methods & NGX_MAIL_AUTH_CRAM_MD5_ENABLED)) {
 496             return NGX_MAIL_PARSE_INVALID_COMMAND;
 497         }
 498
 499         if (ngx_mail_auth_cram_md5_salt(s, c, "+ ", 2) == NGX_OK) {
 500             s->mail_state = ngx_pop3_auth_cram_md5;
 501             return NGX_OK;
 502         }
 503
 504         return NGX_ERROR;
 505     }
 506
 507     return rc;
 508 }