Fix SMTP LOGIN auth method.
[claws.git] / src / common / smtp.c
index 859840338053f436687e47ed17d14cbfb564dc13..4c818d8ede0f8044b3460c947f2a2a4a1152a957 100644 (file)
@@ -1,10 +1,10 @@
 /*
  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
- * Copyright (C) 1999-2003 Hiroyuki Yamamoto
+ * Copyright (C) 1999-2012 Hiroyuki Yamamoto and the Claws Mail team
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * the Free Software Foundation; either version 3 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ * 
  */
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
+#include "claws-features.h"
 #endif
 
 #include <glib.h>
+#ifdef ENABLE_NLS
+#include <glib/gi18n.h>
+#else
+#define _(a) (a)
+#define N_(a) (a)
+#endif
 #include <stdio.h>
 #include <string.h>
 
-#include "intl.h"
 #include "smtp.h"
 #include "md5.h"
-#include "base64.h"
 #include "utils.h"
 #include "log.h"
 
 static void smtp_session_destroy(Session *session);
 
-static gint smtp_from(SMTPSession *session);
-
 static gint smtp_auth(SMTPSession *session);
+#ifdef USE_GNUTLS
 static gint smtp_starttls(SMTPSession *session);
+#endif
 static gint smtp_auth_cram_md5(SMTPSession *session);
 static gint smtp_auth_login(SMTPSession *session);
+static gint smtp_auth_plain(SMTPSession *session);
 
 static gint smtp_ehlo(SMTPSession *session);
 static gint smtp_ehlo_recv(SMTPSession *session, const gchar *msg);
@@ -48,25 +54,22 @@ static gint smtp_helo(SMTPSession *session);
 static gint smtp_rcpt(SMTPSession *session);
 static gint smtp_data(SMTPSession *session);
 static gint smtp_send_data(SMTPSession *session);
-static gint smtp_rset(SMTPSession *session);
-static gint smtp_quit(SMTPSession *session);
+static gint smtp_make_ready(SMTPSession *session);
 static gint smtp_eom(SMTPSession *session);
 
 static gint smtp_session_recv_msg(Session *session, const gchar *msg);
 static gint smtp_session_send_data_finished(Session *session, guint len);
 
 
-Session *smtp_session_new(void)
+Session *smtp_session_new(void *prefs_account)
 {
        SMTPSession *session;
 
        session = g_new0(SMTPSession, 1);
+
+       session_init(SESSION(session), prefs_account, TRUE);
+
        SESSION(session)->type             = SESSION_SMTP;
-       SESSION(session)->server           = NULL;
-       SESSION(session)->port             = 0;
-       SESSION(session)->sock             = NULL;
-       SESSION(session)->state            = SESSION_READY;
-       SESSION(session)->data             = NULL;
 
        SESSION(session)->recv_msg         = smtp_session_recv_msg;
 
@@ -77,7 +80,7 @@ Session *smtp_session_new(void)
 
        session->state                     = SMTP_READY;
 
-#if USE_OPENSSL
+#ifdef USE_GNUTLS
        session->tls_init_done             = FALSE;
 #endif
 
@@ -92,11 +95,15 @@ Session *smtp_session_new(void)
        session->send_data                 = NULL;
        session->send_data_len             = 0;
 
+       session->max_message_size          = -1;
+
        session->avail_auth_type           = 0;
        session->forced_auth_type          = 0;
        session->auth_type                 = 0;
+       session->esmtp_flags               = 0;
 
        session->error_val                 = SM_OK;
+       session->error_msg                 = NULL;
 
        return SESSION(session);
 }
@@ -111,23 +118,37 @@ static void smtp_session_destroy(Session *session)
        g_free(smtp_session->from);
 
        g_free(smtp_session->send_data);
+
+       g_free(smtp_session->error_msg);
 }
 
-static gint smtp_from(SMTPSession *session)
+gint smtp_from(SMTPSession *session)
 {
-       gchar buf[MSGBUFSIZE];
+       gchar buf[MESSAGEBUFSIZE];
+       gchar *mail_size = NULL;
 
-       g_return_val_if_fail(session->from != NULL, SM_ERROR);
+       cm_return_val_if_fail(session->from != NULL, SM_ERROR);
 
        session->state = SMTP_FROM;
+       
+       if (session->is_esmtp && (session->esmtp_flags & ESMTP_SIZE)!=0)
+               mail_size = g_strdup_printf(" SIZE=%d", session->send_data_len);
+       else
+               mail_size = g_strdup("");
+               
 
        if (strchr(session->from, '<'))
-               g_snprintf(buf, sizeof(buf), "MAIL FROM: %s", session->from);
+               g_snprintf(buf, sizeof(buf), "MAIL FROM:%s%s", session->from,
+                          mail_size);
        else
-               g_snprintf(buf, sizeof(buf), "MAIL FROM: <%s>", session->from);
+               g_snprintf(buf, sizeof(buf), "MAIL FROM:<%s>%s", session->from,
+                          mail_size);
+
+       g_free(mail_size);
 
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf);
-       log_print("SMTP> %s\n", buf);
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "%sSMTP> %s\n", (session->is_esmtp?"E":""), buf);
 
        return SM_OK;
 }
@@ -135,20 +156,30 @@ static gint smtp_from(SMTPSession *session)
 static gint smtp_auth(SMTPSession *session)
 {
 
-       g_return_val_if_fail(session->user != NULL, SM_ERROR);
+       cm_return_val_if_fail(session->user != NULL, SM_ERROR);
 
        session->state = SMTP_AUTH;
 
-       if (session->forced_auth_type == SMTPAUTH_CRAM_MD5 ||
-           (session->forced_auth_type == 0 &&
-            (session->avail_auth_type & SMTPAUTH_CRAM_MD5) != 0))
+       if ((session->forced_auth_type == SMTPAUTH_CRAM_MD5
+            || session->forced_auth_type == 0)
+            &&
+            (session->avail_auth_type & SMTPAUTH_CRAM_MD5) != 0)
                smtp_auth_cram_md5(session);
-       else if (session->forced_auth_type == SMTPAUTH_LOGIN ||
-                (session->forced_auth_type == 0 &&
-                 (session->avail_auth_type & SMTPAUTH_LOGIN) != 0))
+       else if ((session->forced_auth_type == SMTPAUTH_LOGIN
+                 || session->forced_auth_type == 0)
+                 &&
+                 (session->avail_auth_type & SMTPAUTH_LOGIN) != 0)
                smtp_auth_login(session);
-       else {
-               log_warning(_("SMTP AUTH not available\n"));
+       else if ((session->forced_auth_type == SMTPAUTH_PLAIN
+                 || session->forced_auth_type == 0)
+                 &&
+                 (session->avail_auth_type & SMTPAUTH_PLAIN) != 0)
+               smtp_auth_plain(session);
+       else if (session->forced_auth_type == 0) {
+               log_warning(LOG_PROTOCOL, _("No SMTP AUTH method available\n"));
+               return SM_AUTHFAIL;
+       } else {
+               log_warning(LOG_PROTOCOL, _("Selected SMTP AUTH method not available\n"));
                return SM_AUTHFAIL;
        }
 
@@ -157,23 +188,29 @@ static gint smtp_auth(SMTPSession *session)
 
 static gint smtp_auth_recv(SMTPSession *session, const gchar *msg)
 {
-       gchar buf[MSGBUFSIZE];
+       gchar buf[MESSAGEBUFSIZE], *tmp;
 
        switch (session->auth_type) {
        case SMTPAUTH_LOGIN:
                session->state = SMTP_AUTH_LOGIN_USER;
 
                if (!strncmp(msg, "334 ", 4)) {
-                       base64_encode(buf, session->user, strlen(session->user));
-
-                       session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
-                                        buf);
-                       log_print("ESMTP> [USERID]\n");
+                       tmp = g_base64_encode(session->user, strlen(session->user));
+                       debug_print("|%s|\n", tmp);
+
+                       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
+                                        tmp) < 0) {
+                               g_free(tmp);
+                               return SM_ERROR;
+                       }
+                       g_free(tmp);
+                       log_print(LOG_PROTOCOL, "ESMTP> [USERID]\n");
                } else {
                        /* Server rejects AUTH */
-                       session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
-                                        "*");
-                       log_print("ESMTP> *\n");
+                       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
+                                        "*") < 0)
+                               return SM_ERROR;
+                       log_print(LOG_PROTOCOL, "ESMTP> *\n");
                }
                break;
        case SMTPAUTH_CRAM_MD5:
@@ -182,14 +219,14 @@ static gint smtp_auth_recv(SMTPSession *session, const gchar *msg)
                if (!strncmp(msg, "334 ", 4)) {
                        gchar *response;
                        gchar *response64;
-                       gchar *challenge;
-                       gint challengelen;
+                       gchar *challenge, *tmp;
+                       gsize challengelen;
                        guchar hexdigest[33];
 
-                       challenge = g_malloc(strlen(msg + 4) + 1);
-                       challengelen = base64_decode(challenge, msg + 4, -1);
-                       challenge[challengelen] = '\0';
-                       log_print("ESMTP< [Decoded: %s]\n", challenge);
+                       tmp = g_base64_decode(msg + 4, &challengelen);
+                       challenge = g_strndup(tmp, challengelen);
+                       g_free(tmp);
+                       log_print(LOG_PROTOCOL, "ESMTP< [Decoded: %s]\n", challenge);
 
                        g_snprintf(buf, sizeof(buf), "%s", session->pass);
                        md5_hex_hmac(hexdigest, challenge, challengelen,
@@ -198,28 +235,32 @@ static gint smtp_auth_recv(SMTPSession *session, const gchar *msg)
 
                        response = g_strdup_printf
                                ("%s %s", session->user, hexdigest);
-                       log_print("ESMTP> [Encoded: %s]\n", response);
+                       log_print(LOG_PROTOCOL, "ESMTP> [Encoded: %s]\n", response);
 
-                       response64 = g_malloc((strlen(response) + 3) * 2 + 1);
-                       base64_encode(response64, response, strlen(response));
+                       response64 = g_base64_encode(response, strlen(response));
                        g_free(response);
 
-                       session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
-                                        response64);
-                       log_print("ESMTP> %s\n", response64);
+                       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
+                                        response64) < 0) {
+                               g_free(response64);
+                               return SM_ERROR;
+                       }
+                       log_print(LOG_PROTOCOL, "ESMTP> %s\n", response64);
                        g_free(response64);
                } else {
                        /* Server rejects AUTH */
-                       session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
-                                        "*");
-                       log_print("ESMTP> *\n");
+                       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL,
+                                        "*") < 0)
+                               return SM_ERROR;
+                       log_print(LOG_PROTOCOL, "ESMTP> *\n");
                }
                break;
        case SMTPAUTH_DIGEST_MD5:
         default:
                /* stop smtp_auth when no correct authtype */
-               session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "*");
-               log_print("ESMTP> *\n");
+               if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "*") < 0)
+                       return SM_ERROR;
+               log_print(LOG_PROTOCOL, "ESMTP> *\n");
                break;
        }
 
@@ -228,25 +269,31 @@ static gint smtp_auth_recv(SMTPSession *session, const gchar *msg)
 
 static gint smtp_auth_login_user_recv(SMTPSession *session, const gchar *msg)
 {
-       gchar buf[MSGBUFSIZE];
+       gchar *tmp;
 
        session->state = SMTP_AUTH_LOGIN_PASS;
 
-       if (!strncmp(msg, "334 ", 4))
-               base64_encode(buf, session->pass, strlen(session->pass));
-       else
+       if (!strncmp(msg, "334 ", 4)) {
+               tmp = g_base64_encode(session->pass, strlen(session->pass));
+       } else {
                /* Server rejects AUTH */
-               g_snprintf(buf, sizeof(buf), "*");
+               tmp = g_strdup("*");
+       }
 
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf);
-       log_print("ESMTP> [PASSWORD]\n");
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, tmp) < 0) {
+               g_free(tmp);
+               return SM_ERROR;
+       }
+       g_free(tmp);
+
+       log_print(LOG_PROTOCOL, "ESMTP> [PASSWORD]\n");
 
        return SM_OK;
 }
 
 static gint smtp_ehlo(SMTPSession *session)
 {
-       gchar buf[MSGBUFSIZE];
+       gchar buf[MESSAGEBUFSIZE];
 
        session->state = SMTP_EHLO;
 
@@ -254,8 +301,9 @@ static gint smtp_ehlo(SMTPSession *session)
 
        g_snprintf(buf, sizeof(buf), "EHLO %s",
                   session->hostname ? session->hostname : get_domain_name());
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf);
-       log_print("ESMTP> %s\n", buf);
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "ESMTP> %s\n", buf);
 
        return SM_OK;
 }
@@ -266,8 +314,10 @@ static gint smtp_ehlo_recv(SMTPSession *session, const gchar *msg)
                const gchar *p = msg;
                p += 3;
                if (*p == '-' || *p == ' ') p++;
-               if (g_strncasecmp(p, "AUTH", 4) == 0) {
+               if (g_ascii_strncasecmp(p, "AUTH", 4) == 0) {
                        p += 5;
+                       if (strcasestr(p, "PLAIN"))
+                               session->avail_auth_type |= SMTPAUTH_PLAIN;
                        if (strcasestr(p, "LOGIN"))
                                session->avail_auth_type |= SMTPAUTH_LOGIN;
                        if (strcasestr(p, "CRAM-MD5"))
@@ -275,6 +325,15 @@ static gint smtp_ehlo_recv(SMTPSession *session, const gchar *msg)
                        if (strcasestr(p, "DIGEST-MD5"))
                                session->avail_auth_type |= SMTPAUTH_DIGEST_MD5;
                }
+               if (g_ascii_strncasecmp(p, "SIZE", 4) == 0) {
+                       p += 5;
+                       session->max_message_size = atoi(p);
+                       session->esmtp_flags |= ESMTP_SIZE;
+               }
+               if (g_ascii_strncasecmp(p, "STARTTLS", 8) == 0) {
+                       p += 9;
+                       session->avail_auth_type |= SMTPAUTH_TLS_AVAILABLE;
+               }
                return SM_OK;
        } else if ((msg[0] == '1' || msg[0] == '2' || msg[0] == '3') &&
            (msg[3] == ' ' || msg[3] == '\0'))
@@ -286,23 +345,57 @@ static gint smtp_ehlo_recv(SMTPSession *session, const gchar *msg)
        return SM_ERROR;
 }
 
+#ifdef USE_GNUTLS
 static gint smtp_starttls(SMTPSession *session)
 {
        session->state = SMTP_STARTTLS;
 
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "STARTTLS");
-       log_print("ESMTP> STARTTLS\n");
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "STARTTLS") < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "ESMTP> STARTTLS\n");
 
        return SM_OK;
 }
+#endif
 
 static gint smtp_auth_cram_md5(SMTPSession *session)
 {
        session->state = SMTP_AUTH;
        session->auth_type = SMTPAUTH_CRAM_MD5;
 
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "AUTH CRAM-MD5");
-       log_print("ESMTP> AUTH CRAM-MD5\n");
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "AUTH CRAM-MD5") < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "ESMTP> AUTH CRAM-MD5\n");
+
+       return SM_OK;
+}
+
+static gint smtp_auth_plain(SMTPSession *session)
+{
+       gchar buf[MESSAGEBUFSIZE], *b64buf, *out;
+       gint len;
+
+       session->state = SMTP_AUTH_PLAIN;
+       session->auth_type = SMTPAUTH_PLAIN;
+
+       memset(buf, 0, sizeof buf);
+
+       /* "\0user\0password" */
+       len = sprintf(buf, "%c%s%c%s", '\0', session->user, '\0', session->pass);
+       b64buf = g_base64_encode(buf, len);
+       out = g_strconcat("AUTH PLAIN ", b64buf, NULL);
+       g_free(b64buf);
+
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, out) < 0) {
+               g_free(out);
+               return SM_ERROR;
+       }
+
+       g_free(out);
+
+       log_print(LOG_PROTOCOL, "ESMTP> [AUTH PLAIN]\n");
+
+       g_free(b64buf);
 
        return SM_OK;
 }
@@ -312,43 +405,46 @@ static gint smtp_auth_login(SMTPSession *session)
        session->state = SMTP_AUTH;
        session->auth_type = SMTPAUTH_LOGIN;
 
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "AUTH LOGIN");
-       log_print("ESMTP> AUTH LOGIN\n");
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "AUTH LOGIN") < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "ESMTP> AUTH LOGIN\n");
 
        return SM_OK;
 }
 
 static gint smtp_helo(SMTPSession *session)
 {
-       gchar buf[MSGBUFSIZE];
+       gchar buf[MESSAGEBUFSIZE];
 
        session->state = SMTP_HELO;
 
        g_snprintf(buf, sizeof(buf), "HELO %s",
                   session->hostname ? session->hostname : get_domain_name());
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf);
-       log_print("SMTP> %s\n", buf);
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "SMTP> %s\n", buf);
 
        return SM_OK;
 }
 
 static gint smtp_rcpt(SMTPSession *session)
 {
-       gchar buf[MSGBUFSIZE];
+       gchar buf[MESSAGEBUFSIZE];
        gchar *to;
 
-       g_return_val_if_fail(session->cur_to != NULL, SM_ERROR);
+       cm_return_val_if_fail(session->cur_to != NULL, SM_ERROR);
 
        session->state = SMTP_RCPT;
 
        to = (gchar *)session->cur_to->data;
 
        if (strchr(to, '<'))
-               g_snprintf(buf, sizeof(buf), "RCPT TO: %s", to);
+               g_snprintf(buf, sizeof(buf), "RCPT TO:%s", to);
        else
-               g_snprintf(buf, sizeof(buf), "RCPT TO: <%s>", to);
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf);
-       log_print("SMTP> %s\n", buf);
+               g_snprintf(buf, sizeof(buf), "RCPT TO:<%s>", to);
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, buf) < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "SMTP> %s\n", buf);
 
        session->cur_to = session->cur_to->next;
 
@@ -359,8 +455,9 @@ static gint smtp_data(SMTPSession *session)
 {
        session->state = SMTP_DATA;
 
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "DATA");
-       log_print("SMTP> DATA\n");
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "DATA") < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "SMTP> DATA\n");
 
        return SM_OK;
 }
@@ -375,22 +472,19 @@ static gint smtp_send_data(SMTPSession *session)
        return SM_OK;
 }
 
-static gint smtp_rset(SMTPSession *session)
+static gint smtp_make_ready(SMTPSession *session)
 {
-       session->state = SMTP_RSET;
-
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "RSET");
-       log_print("SMTP> RSET\n");
+       session->state = SMTP_MAIL_SENT_OK;
 
        return SM_OK;
 }
 
-static gint smtp_quit(SMTPSession *session)
+gint smtp_quit(SMTPSession *session)
 {
        session->state = SMTP_QUIT;
 
        session_send_msg(SESSION(session), SESSION_MSG_NORMAL, "QUIT");
-       log_print("SMTP> QUIT\n");
+       log_print(LOG_PROTOCOL, "SMTP> QUIT\n");
 
        return SM_OK;
 }
@@ -399,8 +493,9 @@ static gint smtp_eom(SMTPSession *session)
 {
        session->state = SMTP_EOM;
 
-       session_send_msg(SESSION(session), SESSION_MSG_NORMAL, ".");
-       log_print("SMTP> . (EOM)\n");
+       if (session_send_msg(SESSION(session), SESSION_MSG_NORMAL, ".") < 0)
+               return SM_ERROR;
+       log_print(LOG_PROTOCOL, "SMTP> . (EOM)\n");
 
        return SM_OK;
 }
@@ -409,9 +504,10 @@ static gint smtp_session_recv_msg(Session *session, const gchar *msg)
 {
        SMTPSession *smtp_session = SMTP_SESSION(session);
        gboolean cont = FALSE;
-
+       gint ret = 0;
+       
        if (strlen(msg) < 4) {
-               log_warning(_("bad SMTP response\n"));
+               log_warning(LOG_PROTOCOL, _("bad SMTP response\n"));
                return -1;
        }
 
@@ -419,138 +515,170 @@ static gint smtp_session_recv_msg(Session *session, const gchar *msg)
        case SMTP_EHLO:
        case SMTP_STARTTLS:
        case SMTP_AUTH:
+       case SMTP_AUTH_PLAIN:
        case SMTP_AUTH_LOGIN_USER:
        case SMTP_AUTH_LOGIN_PASS:
        case SMTP_AUTH_CRAM_MD5:
-               log_print("ESMTP< %s\n", msg);
+               log_print(LOG_PROTOCOL, "ESMTP< %s\n", msg);
                break;
        default:
-               log_print("SMTP< %s\n", msg);
+               log_print(LOG_PROTOCOL, "SMTP< %s\n", msg);
                break;
        }
 
+       /* ignore all multiline responses except for EHLO */
+       if (msg[3] == '-' && smtp_session->state != SMTP_EHLO)
+               return session_recv_msg(session);
+
        if (msg[0] == '5' && msg[1] == '0' &&
            (msg[2] == '4' || msg[2] == '3' || msg[2] == '1')) {
-               log_warning(_("error occurred on SMTP session\n"));
+               log_warning(LOG_PROTOCOL, _("error occurred on SMTP session\n"));
                smtp_session->state = SMTP_ERROR;
                smtp_session->error_val = SM_ERROR;
+               g_free(smtp_session->error_msg);
+               smtp_session->error_msg = g_strdup(msg);
                return -1;
        }
 
-       if (msg[0] == '5' && msg[1] == '3' && msg[2] == '5') {
-               smtp_session->state = SMTP_AUTH_FAILED;
+       if (!strncmp(msg, "535", 3)) {
+               log_warning(LOG_PROTOCOL, _("error occurred on authentication\n"));
+               smtp_session->state = SMTP_ERROR;
+               smtp_session->error_val = SM_AUTHFAIL;
+               g_free(smtp_session->error_msg);
+               smtp_session->error_msg = g_strdup(msg);
                return -1;
        }
 
        if (msg[0] != '1' && msg[0] != '2' && msg[0] != '3') {
-               log_warning(_("error occurred on SMTP session\n"));
+               log_warning(LOG_PROTOCOL, _("error occurred on SMTP session\n"));
                smtp_session->state = SMTP_ERROR;
                smtp_session->error_val = SM_ERROR;
+               g_free(smtp_session->error_msg);
+               smtp_session->error_msg = g_strdup(msg);
                return -1;
        }
 
        if (msg[3] == '-')
                cont = TRUE;
        else if (msg[3] != ' ' && msg[3] != '\0') {
-               log_warning(_("bad SMTP response\n"));
+               log_warning(LOG_PROTOCOL, _("bad SMTP response\n"));
                smtp_session->state = SMTP_ERROR;
                smtp_session->error_val = SM_UNRECOVERABLE;
                return -1;
        }
 
-       /* ignore all multiline responses except for EHLO */
-       if (cont && smtp_session->state != SMTP_EHLO)
-               return 1;
-
        switch (smtp_session->state) {
        case SMTP_READY:
-       case SMTP_CONNECTED:
-#if USE_OPENSSL
-               if (smtp_session->user || session->ssl_type != SSL_NONE)
+               if (strstr(msg, "ESMTP"))
+                       smtp_session->is_esmtp = TRUE;
+#ifdef USE_GNUTLS
+               if (smtp_session->user || session->ssl_type != SSL_NONE ||
+                   smtp_session->is_esmtp)
 #else
-               if (smtp_session->user)
+               if (smtp_session->user || smtp_session->is_esmtp)
 #endif
-                       smtp_ehlo(smtp_session);
+                       ret = smtp_ehlo(smtp_session);
                else
-                       smtp_helo(smtp_session);
+                       ret = smtp_helo(smtp_session);
                break;
        case SMTP_HELO:
-               smtp_from(smtp_session);
+               ret = smtp_from(smtp_session);
                break;
        case SMTP_EHLO:
-               smtp_ehlo_recv(smtp_session, msg);
+               ret = smtp_ehlo_recv(smtp_session, msg);
                if (cont == TRUE)
                        break;
-#if USE_OPENSSL
+               if (smtp_session->max_message_size > 0
+               && smtp_session->max_message_size < 
+                  smtp_session->send_data_len) {
+                       log_warning(LOG_PROTOCOL, _("Message is too big "
+                             "(Maximum size is %s)\n"),
+                             to_human_readable(
+                              (goffset)(smtp_session->max_message_size)));
+                       smtp_session->state = SMTP_ERROR;
+                       smtp_session->error_val = SM_ERROR;
+                       return -1;
+               }
+#ifdef USE_GNUTLS
                if (session->ssl_type == SSL_STARTTLS &&
                    smtp_session->tls_init_done == FALSE) {
-                       smtp_starttls(smtp_session);
+                       ret = smtp_starttls(smtp_session);
                        break;
                }
 #endif
                if (smtp_session->user) {
-                       if (smtp_auth(smtp_session) != SM_OK)
-                               smtp_from(smtp_session);
+                       if (smtp_auth(smtp_session) != SM_OK) {
+#ifdef USE_GNUTLS
+                               if (session->ssl_type == SSL_NONE
+                               &&  smtp_session->tls_init_done == FALSE
+                               &&  (smtp_session->avail_auth_type & SMTPAUTH_TLS_AVAILABLE))
+                                       ret = smtp_starttls(smtp_session);
+                               else
+#endif
+                                       ret = smtp_from(smtp_session);
+                       }
                } else
-                       smtp_from(smtp_session);
+                       ret = smtp_from(smtp_session);
                break;
        case SMTP_STARTTLS:
-#if USE_OPENSSL
+#ifdef USE_GNUTLS
                if (session_start_tls(session) < 0) {
-                       log_warning(_("can't start TLS session\n"));
+                       log_warning(LOG_PROTOCOL, _("couldn't start TLS session\n"));
                        smtp_session->state = SMTP_ERROR;
                        smtp_session->error_val = SM_ERROR;
                        return -1;
                }
                smtp_session->tls_init_done = TRUE;
-               smtp_ehlo(smtp_session);
+               ret = smtp_ehlo(smtp_session);
 #endif
                break;
        case SMTP_AUTH:
-               smtp_auth_recv(smtp_session, msg);
+               ret = smtp_auth_recv(smtp_session, msg);
                break;
        case SMTP_AUTH_LOGIN_USER:
-               smtp_auth_login_user_recv(smtp_session, msg);
+               ret = smtp_auth_login_user_recv(smtp_session, msg);
                break;
+       case SMTP_AUTH_PLAIN:
        case SMTP_AUTH_LOGIN_PASS:
        case SMTP_AUTH_CRAM_MD5:
-               smtp_from(smtp_session);
+               ret = smtp_from(smtp_session);
                break;
        case SMTP_FROM:
                if (smtp_session->cur_to)
-                       smtp_rcpt(smtp_session);
+                       ret = smtp_rcpt(smtp_session);
                break;
        case SMTP_RCPT:
                if (smtp_session->cur_to)
-                       smtp_rcpt(smtp_session);
+                       ret = smtp_rcpt(smtp_session);
                else
-                       smtp_data(smtp_session);
+                       ret = smtp_data(smtp_session);
                break;
        case SMTP_DATA:
-               smtp_send_data(smtp_session);
+               ret = smtp_send_data(smtp_session);
                break;
        case SMTP_EOM:
-               smtp_quit(smtp_session);
+               smtp_make_ready(smtp_session);
                break;
        case SMTP_QUIT:
                session_disconnect(session);
                break;
        case SMTP_ERROR:
-       case SMTP_AUTH_FAILED:
        default:
-               log_warning(_("error occurred on SMTP session\n"));
+               log_warning(LOG_PROTOCOL, _("error occurred on SMTP session\n"));
                smtp_session->error_val = SM_ERROR;
                return -1;
        }
 
-       if (cont)
-               return 1;
+       if (cont && ret == SM_OK)
+               return session_recv_msg(session);
+
+       if (ret != SM_OK)
+               smtp_session->error_val = SM_ERROR;
 
-       return 0;
+       return ret == SM_OK ? 0 : -1;
 }
 
 static gint smtp_session_send_data_finished(Session *session, guint len)
 {
-       smtp_eom(SMTP_SESSION(session));
-       return 0;
+       return smtp_eom(SMTP_SESSION(session));
 }