src/common/smtp.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2009 Hiroyuki Yamamoto and the Claws Mail team
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  17  *
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include "config.h"
  22 #endif
  23
  24 #include <glib.h>
  25 #ifdef ENABLE_NLS
  26 #include <glib/gi18n.h>
  27 #else
  28 #define _(a) (a)
  29 #define N_(a) (a)
  30 #endif
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "smtp.h"
  35 #include "md5.h"
  36 #include "base64.h"
  37 #include "utils.h"
  38 #include "log.h"
  39
  40 static void smtp_session_destroy(Session *session);
  41
  42 static gint smtp_auth(SMTPSession *session);
  43 #ifdef USE_GNUTLS
  44 static gint smtp_starttls(SMTPSession *session);
  45 #endif
  46 static gint smtp_auth_cram_md5(SMTPSession *session);
  47 static gint smtp_auth_login(SMTPSession *session);
  48 static gint smtp_auth_plain(SMTPSession *session);
  49
  50 static gint smtp_ehlo(SMTPSession *session);
  51 static gint smtp_ehlo_recv(SMTPSession *session, const gchar *msg);
  52
  53 static gint smtp_helo(SMTPSession *session);
  54 static gint smtp_rcpt(SMTPSession *session);
  55 static gint smtp_data(SMTPSession *session);
  56 static gint smtp_send_data(SMTPSession *session);
  57 static gint smtp_make_ready(SMTPSession *session);
  58 static gint smtp_eom(SMTPSession *session);
  59
  60 static gint smtp_session_recv_msg(Session *session, const gchar *msg);
  61 static gint smtp_session_send_data_finished(Session *session, guint len);
  62
  63
  64 Session *smtp_session_new(void *prefs_account)
  65 {
  66         SMTPSession *session;
  67
  68         session = g_new0(SMTPSession, 1);
  69
  70         session_init(SESSION(session), prefs_account, TRUE);
  71
  72         SESSION(session)->type             = SESSION_SMTP;
  73
  74         SESSION(session)->recv_msg         = smtp_session_recv_msg;
  75
  76         SESSION(session)->recv_data_finished = NULL;
  77         SESSION(session)->send_data_finished = smtp_session_send_data_finished;
  78
  79         SESSION(session)->destroy          = smtp_session_destroy;
  80
  81         session->state                     = SMTP_READY;
  82
  83 #ifdef USE_GNUTLS
  84         session->tls_init_done             = FALSE;
  85 #endif
  86
  87         session->hostname                  = NULL;
  88         session->user                      = NULL;
  89         session->pass                      = NULL;
  90
  91         session->from                      = NULL;
  92         session->to_list                   = NULL;
  93         session->cur_to                    = NULL;
  94
  95         session->send_data                 = NULL;
  96         session->send_data_len             = 0;
  97
  98         session->max_message_size          = -1;
  99
 100         session->avail_auth_type           = 0;
 101         session->forced_auth_type          = 0;
 102         session->auth_type                 = 0;
 103         session->esmtp_flags               = 0;
 104
 105         session->error_val                 = SM_OK;
 106         session->error_msg                 = NULL;
 107
 108         return SESSION(session);
 109 }
 110
 111 static void smtp_session_destroy(Session *session)
 112 {
 113         SMTPSession *smtp_session = SMTP_SESSION(session);
 114
 115         g_free(smtp_session->hostname);
 116         g_free(smtp_session->user);
 117         g_free(smtp_session->pass);
 118         g_free(smtp_session->from);
 119
 120         g_free(smtp_session->send_data);
 121
 122         g_free(smtp_session->error_msg);
 123 }
 124
 125 gint smtp_from(SMTPSession *session)
 126 {
 127         gchar buf[MSGBUFSIZE];
 128         gchar *mail_size = NULL;
 129
 130         cm_return_val_if_fail(session->from != NULL, SM_ERROR);
 131
 132         session->state = SMTP_FROM;
 133
 134         if (session->is_esmtp && (session->esmtp_flags & ESMTP_SIZE)!=0)
 135                 mail_size = g_strdup_printf(" SIZE=%d", session->send_data_len);
 136         else
 137                 mail_size = g_strdup("");
 138
 139
 140         if (strchr(session->from, '<'))
 141                 g_snprintf(buf, sizeof(buf), "MAIL FROM:%s%s", session->from,
 142                            mail_size);
 143         else
 144                 g_snprintf(buf, sizeof(buf), "MAIL FROM:<%s>%s", session->from,
 145                            mail_size);
 146
 147         g_free(mail_size);
 148
 149         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
 150                 return SM_ERROR;
 151         log_print(LOG_PROTOCOL, "%sSMTP> %s\n", (session->is_esmtp?"E":""), buf);
 152
 153         return SM_OK;
 154 }
 155
 156 static gint smtp_auth(SMTPSession *session)
 157 {
 158
 159         cm_return_val_if_fail(session->user != NULL, SM_ERROR);
 160
 161         session->state = SMTP_AUTH;
 162
 163         if (session->forced_auth_type == SMTPAUTH_CRAM_MD5 ||
 164             (session->forced_auth_type == 0 &&
 165              (session->avail_auth_type & SMTPAUTH_CRAM_MD5) != 0))
 166                 smtp_auth_cram_md5(session);
 167         else if (session->forced_auth_type == SMTPAUTH_LOGIN ||
 168                  (session->forced_auth_type == 0 &&
 169                   (session->avail_auth_type & SMTPAUTH_LOGIN) != 0))
 170                 smtp_auth_login(session);
 171         else if (session->forced_auth_type == SMTPAUTH_PLAIN ||
 172                  (session->forced_auth_type == 0 &&
 173                   (session->avail_auth_type & SMTPAUTH_PLAIN) != 0))
 174                 smtp_auth_plain(session);
 175         else {
 176                 log_warning(LOG_PROTOCOL, _("SMTP AUTH not available\n"));
 177                 return SM_AUTHFAIL;
 178         }
 179
 180         return SM_OK;
 181 }
 182
 183 static gint smtp_auth_recv(SMTPSession *session, const gchar *msg)
 184 {
 185         gchar buf[MSGBUFSIZE];
 186
 187         switch (session->auth_type) {
 188         case SMTPAUTH_LOGIN:
 189                 session->state = SMTP_AUTH_LOGIN_USER;
 190
 191                 if (!strncmp(msg, "334 ", 4)) {
 192                         base64_encode(buf, session->user, strlen(session->user));
 193
 194                         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
 195                                          buf) < 0)
 196                                 return SM_ERROR;
 197                         log_print(LOG_PROTOCOL, "ESMTP> [USERID]\n");
 198                 } else {
 199                         /* Server rejects AUTH */
 200                         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
 201                                          "*") < 0)
 202                                 return SM_ERROR;
 203                         log_print(LOG_PROTOCOL, "ESMTP> *\n");
 204                 }
 205                 break;
 206         case SMTPAUTH_CRAM_MD5:
 207                 session->state = SMTP_AUTH_CRAM_MD5;
 208
 209                 if (!strncmp(msg, "334 ", 4)) {
 210                         gchar *response;
 211                         gchar *response64;
 212                         gchar *challenge;
 213                         gint challengelen;
 214                         guchar hexdigest[33];
 215
 216                         challenge = g_malloc(strlen(msg + 4) + 1);
 217                         challengelen = base64_decode(challenge, msg + 4, -1);
 218                         challenge[challengelen] = '\0';
 219                         log_print(LOG_PROTOCOL, "ESMTP< [Decoded: %s]\n", challenge);
 220
 221                         g_snprintf(buf, sizeof(buf), "%s", session->pass);
 222                         md5_hex_hmac(hexdigest, challenge, challengelen,
 223                                      buf, strlen(session->pass));
 224                         g_free(challenge);
 225
 226                         response = g_strdup_printf
 227                                 ("%s %s", session->user, hexdigest);
 228                         log_print(LOG_PROTOCOL, "ESMTP> [Encoded: %s]\n", response);
 229
 230                         response64 = g_malloc((strlen(response) + 3) * 2 + 1);
 231                         base64_encode(response64, response, strlen(response));
 232                         g_free(response);
 233
 234                         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
 235                                          response64) < 0)
 236                                 return SM_ERROR;
 237                         log_print(LOG_PROTOCOL, "ESMTP> %s\n", response64);
 238                         g_free(response64);
 239                 } else {
 240                         /* Server rejects AUTH */
 241                         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
 242                                          "*") < 0)
 243                                 return SM_ERROR;
 244                         log_print(LOG_PROTOCOL, "ESMTP> *\n");
 245                 }
 246                 break;
 247         case SMTPAUTH_DIGEST_MD5:
 248         default:
 249                 /* stop smtp_auth when no correct authtype */
 250                 if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "*") < 0)
 251                         return SM_ERROR;
 252                 log_print(LOG_PROTOCOL, "ESMTP> *\n");
 253                 break;
 254         }
 255
 256         return SM_OK;
 257 }
 258
 259 static gint smtp_auth_login_user_recv(SMTPSession *session, const gchar *msg)
 260 {
 261         gchar buf[MSGBUFSIZE];
 262
 263         session->state = SMTP_AUTH_LOGIN_PASS;
 264
 265         if (!strncmp(msg, "334 ", 4))
 266                 base64_encode(buf, session->pass, strlen(session->pass));
 267         else
 268                 /* Server rejects AUTH */
 269                 g_snprintf(buf, sizeof(buf), "*");
 270
 271         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
 272                 return SM_ERROR;
 273
 274         log_print(LOG_PROTOCOL, "ESMTP> [PASSWORD]\n");
 275
 276         return SM_OK;
 277 }
 278
 279 static gint smtp_ehlo(SMTPSession *session)
 280 {
 281         gchar buf[MSGBUFSIZE];
 282
 283         session->state = SMTP_EHLO;
 284
 285         session->avail_auth_type = 0;
 286
 287         g_snprintf(buf, sizeof(buf), "EHLO %s",
 288                    session->hostname ? session->hostname : get_domain_name());
 289         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
 290                 return SM_ERROR;
 291         log_print(LOG_PROTOCOL, "ESMTP> %s\n", buf);
 292
 293         return SM_OK;
 294 }
 295
 296 static gint smtp_ehlo_recv(SMTPSession *session, const gchar *msg)
 297 {
 298         if (strncmp(msg, "250", 3) == 0) {
 299                 const gchar *p = msg;
 300                 p += 3;
 301                 if (*p == '-' || *p == ' ') p++;
 302                 if (g_ascii_strncasecmp(p, "AUTH", 4) == 0) {
 303                         p += 5;
 304                         if (strcasestr(p, "PLAIN"))
 305                                 session->avail_auth_type |= SMTPAUTH_PLAIN;
 306                         if (strcasestr(p, "LOGIN"))
 307                                 session->avail_auth_type |= SMTPAUTH_LOGIN;
 308                         if (strcasestr(p, "CRAM-MD5"))
 309                                 session->avail_auth_type |= SMTPAUTH_CRAM_MD5;
 310                         if (strcasestr(p, "DIGEST-MD5"))
 311                                 session->avail_auth_type |= SMTPAUTH_DIGEST_MD5;
 312                 }
 313                 if (g_ascii_strncasecmp(p, "SIZE", 4) == 0) {
 314                         p += 5;
 315                         session->max_message_size = atoi(p);
 316                         session->esmtp_flags |= ESMTP_SIZE;
 317                 }
 318                 if (g_ascii_strncasecmp(p, "STARTTLS", 8) == 0) {
 319                         p += 9;
 320                         session->avail_auth_type |= SMTPAUTH_TLS_AVAILABLE;
 321                 }
 322                 return SM_OK;
 323         } else if ((msg[0] == '1' || msg[0] == '2' || msg[0] == '3') &&
 324             (msg[3] == ' ' || msg[3] == '\0'))
 325                 return SM_OK;
 326         else if (msg[0] == '5' && msg[1] == '0' &&
 327                  (msg[2] == '4' || msg[2] == '3' || msg[2] == '1'))
 328                 return SM_ERROR;
 329
 330         return SM_ERROR;
 331 }
 332
 333 #ifdef USE_GNUTLS
 334 static gint smtp_starttls(SMTPSession *session)
 335 {
 336         session->state = SMTP_STARTTLS;
 337
 338         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "STARTTLS") < 0)
 339                 return SM_ERROR;
 340         log_print(LOG_PROTOCOL, "ESMTP> STARTTLS\n");
 341
 342         return SM_OK;
 343 }
 344 #endif
 345
 346 static gint smtp_auth_cram_md5(SMTPSession *session)
 347 {
 348         session->state = SMTP_AUTH;
 349         session->auth_type = SMTPAUTH_CRAM_MD5;
 350
 351         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "AUTH CRAM-MD5") < 0)
 352                 return SM_ERROR;
 353         log_print(LOG_PROTOCOL, "ESMTP> AUTH CRAM-MD5\n");
 354
 355         return SM_OK;
 356 }
 357
 358 static gint smtp_auth_plain(SMTPSession *session)
 359 {
 360         gchar buf[MSGBUFSIZE];
 361
 362         /*
 363          * +1      +1      +1
 364          * \0<user>\0<pass>\0
 365          */
 366         int b64len = (1 + strlen(session->user) + 1 + strlen(session->pass) + 1);
 367         gchar *b64buf = g_malloc(b64len);
 368
 369         /* use the char *ptr to walk the base64 string with embedded \0 */
 370         char  *a = b64buf;
 371         int  b64cnt = 0;
 372
 373         session->state = SMTP_AUTH_PLAIN;
 374         session->auth_type = SMTPAUTH_PLAIN;
 375
 376         memset(buf, 0, sizeof buf);
 377
 378         /*
 379          * have to construct the string bit by bit. sprintf can't do it in one.
 380          * first field is null, so string is \0<user>\0<password>
 381          */
 382         *a = 0;
 383         a++;
 384
 385         g_snprintf (a, b64len - 1, "%s", session->user);
 386
 387         b64cnt = strlen(session->user)+1;
 388         a += b64cnt;
 389
 390         g_snprintf (a, b64len - b64cnt - 1, "%s", session->pass);
 391         b64cnt += strlen(session->pass) + 1;
 392
 393         /*
 394          * reuse the char *ptr to offset into the textbuf to meld
 395          * the plaintext ESMTP message and the base64 string value
 396          */
 397         strcpy(buf, "AUTH PLAIN ");
 398         a = buf + strlen(buf);
 399         base64_encode(a, b64buf, b64cnt);
 400
 401         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
 402                 return SM_ERROR;
 403
 404         log_print(LOG_PROTOCOL, "ESMTP> [AUTH PLAIN]\n");
 405
 406         g_free(b64buf);
 407
 408         return SM_OK;
 409 }
 410
 411 static gint smtp_auth_login(SMTPSession *session)
 412 {
 413         session->state = SMTP_AUTH;
 414         session->auth_type = SMTPAUTH_LOGIN;
 415
 416         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "AUTH LOGIN") < 0)
 417                 return SM_ERROR;
 418         log_print(LOG_PROTOCOL, "ESMTP> AUTH LOGIN\n");
 419
 420         return SM_OK;
 421 }
 422
 423 static gint smtp_helo(SMTPSession *session)
 424 {
 425         gchar buf[MSGBUFSIZE];
 426
 427         session->state = SMTP_HELO;
 428
 429         g_snprintf(buf, sizeof(buf), "HELO %s",
 430                    session->hostname ? session->hostname : get_domain_name());
 431         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
 432                 return SM_ERROR;
 433         log_print(LOG_PROTOCOL, "SMTP> %s\n", buf);
 434
 435         return SM_OK;
 436 }
 437
 438 static gint smtp_rcpt(SMTPSession *session)
 439 {
 440         gchar buf[MSGBUFSIZE];
 441         gchar *to;
 442
 443         cm_return_val_if_fail(session->cur_to != NULL, SM_ERROR);
 444
 445         session->state = SMTP_RCPT;
 446
 447         to = (gchar *)session->cur_to->data;
 448
 449         if (strchr(to, '<'))
 450                 g_snprintf(buf, sizeof(buf), "RCPT TO:%s", to);
 451         else
 452                 g_snprintf(buf, sizeof(buf), "RCPT TO:<%s>", to);
 453         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
 454                 return SM_ERROR;
 455         log_print(LOG_PROTOCOL, "SMTP> %s\n", buf);
 456
 457         session->cur_to = session->cur_to->next;
 458
 459         return SM_OK;
 460 }
 461
 462 static gint smtp_data(SMTPSession *session)
 463 {
 464         session->state = SMTP_DATA;
 465
 466         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "DATA") < 0)
 467                 return SM_ERROR;
 468         log_print(LOG_PROTOCOL, "SMTP> DATA\n");
 469
 470         return SM_OK;
 471 }
 472
 473 static gint smtp_send_data(SMTPSession *session)
 474 {
 475         session->state = SMTP_SEND_DATA;
 476
 477         session_send_data(SESSION(session), session->send_data,
 478                           session->send_data_len);
 479
 480         return SM_OK;
 481 }
 482
 483 static gint smtp_make_ready(SMTPSession *session)
 484 {
 485         session->state = SMTP_MAIL_SENT_OK;
 486
 487         return SM_OK;
 488 }
 489
 490 gint smtp_quit(SMTPSession *session)
 491 {
 492         session->state = SMTP_QUIT;
 493
 494         session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "QUIT");
 495         log_print(LOG_PROTOCOL, "SMTP> QUIT\n");
 496
 497         return SM_OK;
 498 }
 499
 500 static gint smtp_eom(SMTPSession *session)
 501 {
 502         session->state = SMTP_EOM;
 503
 504         if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, ".") < 0)
 505                 return SM_ERROR;
 506         log_print(LOG_PROTOCOL, "SMTP> . (EOM)\n");
 507
 508         return SM_OK;
 509 }
 510
 511 static gint smtp_session_recv_msg(Session *session, const gchar *msg)
 512 {
 513         SMTPSession *smtp_session = SMTP_SESSION(session);
 514         gboolean cont = FALSE;
 515         gint ret = 0;
 516
 517         if (strlen(msg) < 4) {
 518                 log_warning(LOG_PROTOCOL, _("bad SMTP response\n"));
 519                 return -1;
 520         }
 521
 522         switch (smtp_session->state) {
 523         case SMTP_EHLO:
 524         case SMTP_STARTTLS:
 525         case SMTP_AUTH:
 526         case SMTP_AUTH_PLAIN:
 527         case SMTP_AUTH_LOGIN_USER:
 528         case SMTP_AUTH_LOGIN_PASS:
 529         case SMTP_AUTH_CRAM_MD5:
 530                 log_print(LOG_PROTOCOL, "ESMTP< %s\n", msg);
 531                 break;
 532         default:
 533                 log_print(LOG_PROTOCOL, "SMTP< %s\n", msg);
 534                 break;
 535         }
 536
 537         if (msg[0] == '5' && msg[1] == '0' &&
 538             (msg[2] == '4' || msg[2] == '3' || msg[2] == '1')) {
 539                 log_warning(LOG_PROTOCOL, _("error occurred on SMTP session\n"));
 540                 smtp_session->state = SMTP_ERROR;
 541                 smtp_session->error_val = SM_ERROR;
 542                 g_free(smtp_session->error_msg);
 543                 smtp_session->error_msg = g_strdup(msg);
 544                 return -1;
 545         }
 546
 547         if (!strncmp(msg, "535", 3)) {
 548                 log_warning(LOG_PROTOCOL, _("error occurred on authentication\n"));
 549                 smtp_session->state = SMTP_ERROR;
 550                 smtp_session->error_val = SM_AUTHFAIL;
 551                 g_free(smtp_session->error_msg);
 552                 smtp_session->error_msg = g_strdup(msg);
 553                 return -1;
 554         }
 555
 556         if (msg[0] != '1' && msg[0] != '2' && msg[0] != '3') {
 557                 log_warning(LOG_PROTOCOL, _("error occurred on SMTP session\n"));
 558                 smtp_session->state = SMTP_ERROR;
 559                 smtp_session->error_val = SM_ERROR;
 560                 g_free(smtp_session->error_msg);
 561                 smtp_session->error_msg = g_strdup(msg);
 562                 return -1;
 563         }
 564
 565         if (msg[3] == '-')
 566                 cont = TRUE;
 567         else if (msg[3] != ' ' && msg[3] != '\0') {
 568                 log_warning(LOG_PROTOCOL, _("bad SMTP response\n"));
 569                 smtp_session->state = SMTP_ERROR;
 570                 smtp_session->error_val = SM_UNRECOVERABLE;
 571                 return -1;
 572         }
 573
 574         /* ignore all multiline responses except for EHLO */
 575         if (cont && smtp_session->state != SMTP_EHLO)
 576                 return session_recv_msg(session);
 577
 578         switch (smtp_session->state) {
 579         case SMTP_READY:
 580                 if (strstr(msg, "ESMTP"))
 581                         smtp_session->is_esmtp = TRUE;
 582         case SMTP_CONNECTED:
 583 #ifdef USE_GNUTLS
 584                 if (smtp_session->user || session->ssl_type != SSL_NONE ||
 585                     smtp_session->is_esmtp)
 586 #else
 587                 if (smtp_session->user || smtp_session->is_esmtp)
 588 #endif
 589                         ret = smtp_ehlo(smtp_session);
 590                 else
 591                         ret = smtp_helo(smtp_session);
 592                 break;
 593         case SMTP_HELO:
 594                 ret = smtp_from(smtp_session);
 595                 break;
 596         case SMTP_EHLO:
 597                 ret = smtp_ehlo_recv(smtp_session, msg);
 598                 if (cont == TRUE)
 599                         break;
 600                 if (smtp_session->max_message_size > 0
 601                 && smtp_session->max_message_size <
 602                    smtp_session->send_data_len) {
 603                         log_warning(LOG_PROTOCOL, _("Message is too big "
 604                               "(Maximum size is %s)\n"),
 605                               to_human_readable(
 606                                (goffset)(smtp_session->max_message_size)));
 607                         smtp_session->state = SMTP_ERROR;
 608                         smtp_session->error_val = SM_ERROR;
 609                         return -1;
 610                 }
 611 #ifdef USE_GNUTLS
 612                 if (session->ssl_type == SSL_STARTTLS &&
 613                     smtp_session->tls_init_done == FALSE) {
 614                         ret = smtp_starttls(smtp_session);
 615                         break;
 616                 }
 617 #endif
 618                 if (smtp_session->user) {
 619                         if (smtp_auth(smtp_session) != SM_OK) {
 620 #ifdef USE_GNUTLS
 621                                 if (session->ssl_type == SSL_NONE
 622                                 &&  smtp_session->tls_init_done == FALSE
 623                                 &&  (smtp_session->avail_auth_type & SMTPAUTH_TLS_AVAILABLE))
 624                                         ret = smtp_starttls(smtp_session);
 625                                 else
 626 #endif
 627                                         ret = smtp_from(smtp_session);
 628                         }
 629                 } else
 630                         ret = smtp_from(smtp_session);
 631                 break;
 632         case SMTP_STARTTLS:
 633 #ifdef USE_GNUTLS
 634                 if (session_start_tls(session) < 0) {
 635                         log_warning(LOG_PROTOCOL, _("couldn't start TLS session\n"));
 636                         smtp_session->state = SMTP_ERROR;
 637                         smtp_session->error_val = SM_ERROR;
 638                         return -1;
 639                 }
 640                 smtp_session->tls_init_done = TRUE;
 641                 ret = smtp_ehlo(smtp_session);
 642 #endif
 643                 break;
 644         case SMTP_AUTH:
 645                 ret = smtp_auth_recv(smtp_session, msg);
 646                 break;
 647         case SMTP_AUTH_LOGIN_USER:
 648                 ret = smtp_auth_login_user_recv(smtp_session, msg);
 649                 break;
 650         case SMTP_AUTH_PLAIN:
 651         case SMTP_AUTH_LOGIN_PASS:
 652         case SMTP_AUTH_CRAM_MD5:
 653                 ret = smtp_from(smtp_session);
 654                 break;
 655         case SMTP_FROM:
 656                 if (smtp_session->cur_to)
 657                         ret = smtp_rcpt(smtp_session);
 658                 break;
 659         case SMTP_RCPT:
 660                 if (smtp_session->cur_to)
 661                         ret = smtp_rcpt(smtp_session);
 662                 else
 663                         ret = smtp_data(smtp_session);
 664                 break;
 665         case SMTP_DATA:
 666                 ret = smtp_send_data(smtp_session);
 667                 break;
 668         case SMTP_EOM:
 669                 smtp_make_ready(smtp_session);
 670                 break;
 671         case SMTP_QUIT:
 672                 session_disconnect(session);
 673                 break;
 674         case SMTP_ERROR:
 675         default:
 676                 log_warning(LOG_PROTOCOL, _("error occurred on SMTP session\n"));
 677                 smtp_session->error_val = SM_ERROR;
 678                 return -1;
 679         }
 680
 681         if (cont && ret == SM_OK)
 682                 return session_recv_msg(session);
 683
 684         if (ret != SM_OK)
 685                 smtp_session->error_val = SM_ERROR;
 686
 687         return ret == SM_OK ? 0 : -1;
 688 }
 689
 690 static gint smtp_session_send_data_finished(Session *session, guint len)
 691 {
 692         return smtp_eom(SMTP_SESSION(session));
 693 }