Initial revision

1 files changed, 982 insertions, 0 deletions

diff --git a/kmicromail/libetpan/smtp/mailsmtp.c b/kmicromail/libetpan/smtp/mailsmtp.c
new file mode 100644
index 0000000..b3be432
--- a/dev/null
+++ b/kmicromail/libetpan/smtp/mailsmtp.c
@@ -0,0 +1,982 @@
+/*
+ * libEtPan! -- a mail stuff library
+ *
+ * Copyright (C) 2001, 2002 - DINH Viet Hoa,
+ * All rights reserved.
+ *
+ * SMTP AUTH support by Juergen Graf
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the libEtPan! project nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * $Id$
+ */
+
+#include "mailsmtp.h"
+#include "connect.h"
+#include "md5.h"
+#include "base64.h"
+#include "mail.h"
+
+#include <netinet/in.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+
+
+/*
+  RFC 2821 : SMTP
+  RFC 1891 : SMTP Service Extension for Delivery Status Notifications
+
+  RFC 1428 : Transition of Internet Mail from Just-Send-8 to 8bit-SMTP/MIME
+  RFC 1652 : SMTP Service Extension for 8bit-MIMEtransport
+  RFC 1845 : SMTP Service Extension for Checkpoint/Restart
+  RFC 1846 : SMTP 521 Reply Code
+  RFC 1870 : SMTP Service Extension for Message Size Declaration
+  RFC 1985 : SMTP Service Extension for Remote Message Queue Starting
+  RFC 2034 : SMTP Service Extension for Returning Enhanced Error Codes
+  RFC 2442 : The Batch SMTP Media Type
+  RFC 2487 : SMTP Service Extension for Secure SMTP over TLS
+  RFC 2505 : Anti-Spam Recommendations for SMTP MTAs
+  RFC 2554 : SMTP Service Extension for Authentication
+  RFC 2645 : ON-DEMAND MAIL RELAY (ODMR) SMTP with Dynamic IP Addresses
+  RFC 2852 : Deliver By SMTP Service Extension
+  RFC 2920 : SMTP Service Extension for Command Pipelining
+  RFC 3030 : SMTP Service Extensions for Transmission of Large and Binary MIME
+     Messages
+*/
+
+#define SMTP_STATUS_CONTINUE 0x1000
+
+mailsmtp * mailsmtp_new(size_t progr_rate,
+			progress_function * progr_fun)
+{
+  mailsmtp * session;
+
+  session = malloc(sizeof(* session));
+  if (session == NULL)
+    goto err;
+
+  session->stream = NULL;
+
+  session->progr_rate = progr_rate;
+  session->progr_fun = progr_fun;
+
+  session->response = NULL;
+
+  session->line_buffer = mmap_string_new("");
+  if (session->line_buffer == NULL)
+    goto free_session;
+
+  session->response_buffer = mmap_string_new("");
+  if (session->response_buffer == NULL)
+    goto free_line_buffer;
+
+  session->esmtp = 0;
+  session->auth = MAILSMTP_AUTH_NOT_CHECKED;
+
+  return session;
+
+ free_line_buffer:
+  mmap_string_free(session->line_buffer);
+ free_session:
+  free(session);
+ err:
+  return NULL;
+}
+
+void mailsmtp_free(mailsmtp * session)
+{
+  if (session->stream)
+    mailsmtp_quit(session);
+
+  mmap_string_free(session->line_buffer);
+  mmap_string_free(session->response_buffer);
+  free(session);
+}
+
+static int send_command(mailsmtp * f, char * command);
+
+static int read_response(mailsmtp * session);
+
+/* smtp operations */
+
+int mailsmtp_connect(mailsmtp * session, mailstream * s)
+{
+  int code;
+
+  session->stream = s;
+
+  code = read_response(session);
+
+  switch (code) {
+  case 220:
+    return MAILSMTP_NO_ERROR;
+      
+  case 554:
+    session->stream = NULL;
+    mailstream_close(s);
+    return MAILSMTP_ERROR_SERVICE_NOT_AVAILABLE;
+      
+  default:
+    session->stream = NULL;
+    mailstream_close(s);
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+
+#define SMTP_STRING_SIZE 513
+
+int mailsmtp_quit(mailsmtp * session)
+{
+  char command[SMTP_STRING_SIZE];
+  int r;
+
+  snprintf(command, SMTP_STRING_SIZE, "QUIT\r\n");
+  r = send_command(session, command);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+  if (r == 0)
+    return MAILSMTP_ERROR_STREAM;
+  mailstream_close(session->stream);
+  session->stream = NULL;
+  
+  return MAILSMTP_NO_ERROR;
+}
+
+
+
+#define HOSTNAME_SIZE 256
+
+int mailsmtp_helo(mailsmtp * session)
+{
+  int r;
+  char hostname[HOSTNAME_SIZE];
+  char command[SMTP_STRING_SIZE];
+
+  r = gethostname(hostname, HOSTNAME_SIZE);
+  if (r < 0)
+    return MAILSMTP_ERROR_HOSTNAME;
+
+  snprintf(command, SMTP_STRING_SIZE, "HELO %s\r\n", hostname);
+  r = send_command(session, command);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+  
+  switch (r) {
+  case 250:
+    return MAILSMTP_NO_ERROR;
+    
+  case 504:
+    return MAILSMTP_ERROR_NOT_IMPLEMENTED;
+
+  case 550:
+    return MAILSMTP_ERROR_ACTION_NOT_TAKEN;
+
+  case 0:
+    return MAILSMTP_ERROR_STREAM;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+int mailsmtp_mail(mailsmtp * session, const char * from)
+{
+  int r;
+  char command[SMTP_STRING_SIZE];
+
+  snprintf(command, SMTP_STRING_SIZE, "MAIL FROM:<%s>\r\n", from);
+  r = send_command(session, command);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+
+  switch (r) {
+  case 250:
+    return MAILSMTP_NO_ERROR;
+
+  case 552:
+    return MAILSMTP_ERROR_EXCEED_STORAGE_ALLOCATION;
+
+  case 451:
+    return MAILSMTP_ERROR_IN_PROCESSING;
+
+  case 452:
+    return MAILSMTP_ERROR_INSUFFICIENT_SYSTEM_STORAGE;
+
+  case 550:
+    return MAILSMTP_ERROR_MAILBOX_UNAVAILABLE;
+
+  case 553:
+    return MAILSMTP_ERROR_MAILBOX_NAME_NOT_ALLOWED;
+
+  case 503:
+    return MAILSMTP_ERROR_BAD_SEQUENCE_OF_COMMAND;
+
+  case 0:
+    return MAILSMTP_ERROR_STREAM;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+int mailsmtp_rcpt(mailsmtp * session, const char * to)
+{
+  return mailesmtp_rcpt(session, to, 0, NULL);
+}
+
+int mailsmtp_data(mailsmtp * session)
+{
+  int r;
+  char command[SMTP_STRING_SIZE];
+
+  snprintf(command, SMTP_STRING_SIZE, "DATA\r\n");
+  r = send_command(session, command);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+
+  switch (r) {
+  case 354:
+    return MAILSMTP_NO_ERROR;
+
+  case 451:
+    return MAILSMTP_ERROR_IN_PROCESSING;
+
+  case 554:
+    return MAILSMTP_ERROR_TRANSACTION_FAILED;
+
+  case 503:
+    return MAILSMTP_ERROR_BAD_SEQUENCE_OF_COMMAND;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+static int send_data(mailsmtp * session, const char * message, size_t size);
+
+int mailsmtp_data_message(mailsmtp * session,
+			   const char * message,
+			   size_t size)
+{
+  int r;
+
+  r = send_data(session, message, size);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+
+  r = read_response(session);
+
+  switch(r) {
+  case 250:
+    return MAILSMTP_NO_ERROR;
+      
+  case 552:
+    return MAILSMTP_ERROR_EXCEED_STORAGE_ALLOCATION;
+
+  case 554:
+    return MAILSMTP_ERROR_TRANSACTION_FAILED;
+      
+  case 451:
+    return MAILSMTP_ERROR_IN_PROCESSING;
+      
+  case 452:
+    return MAILSMTP_ERROR_INSUFFICIENT_SYSTEM_STORAGE;
+
+  case 0:
+    return MAILSMTP_ERROR_STREAM;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+/* esmtp operations */
+
+
+/**
+ * called during mailesmtp_ehlo
+ * checks EHLO answer for server extensions and sets flags
+ * in session->esmtp
+ * checks AUTH methods in session->response and sets flags
+ * in session->auth
+ */
+#define isdelim(x) ((x) == ' ' || (x) == '\r' || (x) == '\n' || (x) == '\0')
+
+int mailesmtp_parse_ehlo(mailsmtp * session)
+{
+  char * response;
+  
+  /* restore data */
+  session->esmtp = MAILSMTP_ESMTP;
+  session->auth = MAILSMTP_AUTH_CHECKED;
+
+  response = session->response;
+  
+  /* ESMTP supported extensions :
+     DSN
+     EXPN
+     8BITMIME
+     SIZE [<n>]
+     ETRN
+     STARTTLS
+     AUTH <mechanisms...>
+  */
+  while (response != NULL) {
+    if (!strncasecmp(response, "EXPN", 4) && isdelim(response[4])) 
+      session->esmtp |= MAILSMTP_ESMTP_EXPN;
+    else if (!strncasecmp(response, "ETRN", 4) && isdelim(response[4]))
+      session->esmtp |= MAILSMTP_ESMTP_ETRN;
+    else if (!strncasecmp(response, "DSN", 3) && isdelim(response[3]))
+      session->esmtp |= MAILSMTP_ESMTP_DSN;
+    else if (!strncasecmp(response, "8BITMIME", 8) && isdelim(response[8]))
+      session->esmtp |= MAILSMTP_ESMTP_8BITMIME;
+    else if (!strncasecmp(response, "STARTTLS", 8) && isdelim(response[8]))
+      session->esmtp |= MAILSMTP_ESMTP_STARTTLS;
+    else if (!strncasecmp(response, "SIZE", 4) && isdelim(response[4])) {
+      session->esmtp |= MAILSMTP_ESMTP_SIZE;
+      /* TODO: grab optionnal max size */
+    } else if (!strncasecmp(response, "AUTH ", 5)) {
+      response += 5;       /* remove "AUTH " */
+      while (response[0] != '\n' && response[0] != '\0') {
+	while (response[0] == ' ') response++;
+	if (strncasecmp(response, "LOGIN", 5) == 0) {
+	  session->auth |= MAILSMTP_AUTH_LOGIN;
+	  response += 5;
+	} else if (strncasecmp(response, "CRAM-MD5", 8) == 0) {
+	  session->auth |= MAILSMTP_AUTH_CRAM_MD5;
+	  response += 8;
+	} else if (strncasecmp(response, "PLAIN", 5) == 0) {
+	  session->auth |= MAILSMTP_AUTH_PLAIN;
+	  response += 5;
+	} else {
+	  /* unknown auth method - jump to next word or eol */
+	  while (!isdelim(response[0]) || response[0] == '\r')
+	    response++;
+	}
+      }
+    }
+    response = strpbrk(response, "\n");
+    if (response != NULL)
+      response++;
+  }
+  
+  return MAILSMTP_NO_ERROR;
+}
+
+
+int mailesmtp_ehlo(mailsmtp * session)
+{
+  int r;
+  char hostname[HOSTNAME_SIZE];
+  char command[SMTP_STRING_SIZE];
+
+  r = gethostname(hostname, HOSTNAME_SIZE);
+  if (r != 0)
+    return MAILSMTP_ERROR_HOSTNAME;
+
+  snprintf(command, SMTP_STRING_SIZE, "EHLO %s\r\n", hostname);
+  r = send_command(session, command);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+  
+  switch (r) {
+  case 250:
+    return mailesmtp_parse_ehlo(session);
+    
+  case 504:
+    return MAILSMTP_ERROR_NOT_IMPLEMENTED;
+
+  case 550:
+    return MAILSMTP_ERROR_ACTION_NOT_TAKEN;
+
+  case 0:
+    return MAILSMTP_ERROR_STREAM;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+/*
+  if return_full is TRUE, the entire message is returned on error
+  envid can be NULL
+*/
+
+
+int mailesmtp_mail(mailsmtp * session,
+		    const char * from,
+		    int return_full,
+		    const char * envid)
+{
+  int r;
+  char command[SMTP_STRING_SIZE];
+  char *body = "";
+
+#if notyet
+  /* TODO: figure out a way for the user to explicity enable this or not */
+  if (session->esmtp & MAILSMTP_ESMTP_8BITMIME)
+    body = " BODY=8BITMIME";
+#endif
+  
+  if (session->esmtp & MAILSMTP_ESMTP_DSN) {
+    if (envid)
+      snprintf(command, SMTP_STRING_SIZE, "MAIL FROM:<%s> RET=%s ENVID=%s%s\r\n",
+	       from, return_full ? "FULL" : "HDRS", envid, body);
+    else
+      snprintf(command, SMTP_STRING_SIZE, "MAIL FROM:<%s> RET=%s%s\r\n",
+	       from, return_full ? "FULL" : "HDRS", body);
+  } else
+    snprintf(command, SMTP_STRING_SIZE, "MAIL FROM:<%s>%s\r\n",
+	     from, body);
+
+  r = send_command(session, command);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+
+  switch (r) {
+  case 250:
+    return MAILSMTP_NO_ERROR;
+
+  case 552:
+    return MAILSMTP_ERROR_EXCEED_STORAGE_ALLOCATION;
+
+  case 451:
+    return MAILSMTP_ERROR_IN_PROCESSING;
+
+  case 452:
+    return MAILSMTP_ERROR_INSUFFICIENT_SYSTEM_STORAGE;
+
+  case 550:
+    return MAILSMTP_ERROR_MAILBOX_UNAVAILABLE;
+
+  case 553:
+    return MAILSMTP_ERROR_MAILBOX_NAME_NOT_ALLOWED;
+
+  case 503:
+    return MAILSMTP_ERROR_BAD_SEQUENCE_OF_COMMAND;
+
+  case 0:
+    return MAILSMTP_ERROR_STREAM;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+int mailesmtp_rcpt(mailsmtp * session,
+		    const char * to,
+		    int notify,
+		    const char * orcpt)
+{
+  int r;
+  char command[SMTP_STRING_SIZE];
+  char notify_str[30] = "";
+  char notify_info_str[30] = "";
+
+  if (notify != 0 && session->esmtp & MAILSMTP_ESMTP_DSN) {
+    if (notify & MAILSMTP_DSN_NOTIFY_SUCCESS)
+      strcat(notify_info_str, ",SUCCESS");
+    if (notify & MAILSMTP_DSN_NOTIFY_FAILURE)
+      strcat(notify_info_str, ",FAILURE");
+    if (notify & MAILSMTP_DSN_NOTIFY_DELAY)
+      strcat(notify_info_str, ",DELAY");
+
+    if (notify & MAILSMTP_DSN_NOTIFY_NEVER)
+      strcpy(notify_info_str, ",NEVER");
+
+    notify_info_str[0] = '=';
+
+    strcpy(notify_str, " NOTIFY");
+    strcat(notify_str, notify_info_str);
+  }
+
+  if (orcpt && session->esmtp & MAILSMTP_ESMTP_DSN)
+    snprintf(command, SMTP_STRING_SIZE, "RCPT TO:<%s>%s ORCPT=%s\r\n",
+	     to, notify_str, orcpt);
+  else
+    snprintf(command, SMTP_STRING_SIZE, "RCPT TO:<%s>%s\r\n", to, notify_str);
+
+  r = send_command(session, command);
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+
+  switch (r) {
+  case 250:
+    return MAILSMTP_NO_ERROR;
+
+  case 251: /* not local user, will be forwarded */
+    return MAILSMTP_NO_ERROR;
+
+  case 550:
+  case 450:
+    return MAILSMTP_ERROR_MAILBOX_UNAVAILABLE;
+
+  case 551:
+    return MAILSMTP_ERROR_USER_NOT_LOCAL;
+
+  case 552:
+    return MAILSMTP_ERROR_EXCEED_STORAGE_ALLOCATION;
+
+  case 553:
+    return MAILSMTP_ERROR_MAILBOX_NAME_NOT_ALLOWED;
+
+  case 451:
+    return MAILSMTP_ERROR_IN_PROCESSING;
+
+  case 452:
+    return MAILSMTP_ERROR_INSUFFICIENT_SYSTEM_STORAGE;
+
+  case 503:
+    return MAILSMTP_ERROR_BAD_SEQUENCE_OF_COMMAND;
+
+  case 0:
+    return MAILSMTP_ERROR_STREAM;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+int auth_map_errors(int err)
+{
+  switch (err) {
+  case 235:
+    return MAILSMTP_NO_ERROR;     /* AUTH successfull */
+  case 334:
+    return MAILSMTP_NO_ERROR;     /* AUTH in progress */
+  case 432:
+    return MAILSMTP_ERROR_AUTH_TRANSITION_NEEDED;
+  case 454:
+    return MAILSMTP_ERROR_AUTH_TEMPORARY_FAILTURE;
+  case 504:
+    return MAILSMTP_ERROR_AUTH_NOT_SUPPORTED;
+  case 530:
+    return MAILSMTP_ERROR_AUTH_REQUIRED;
+  case 534:
+    return MAILSMTP_ERROR_AUTH_TOO_WEAK;
+  case 538:
+    return MAILSMTP_ERROR_AUTH_ENCRYPTION_REQUIRED;
+  default:
+    /* opportunistic approach ;) */
+    return MAILSMTP_NO_ERROR;
+  }
+}
+
+static int mailsmtp_auth_login(mailsmtp * session,
+    const char * user, const char * pass)
+{
+  int err;
+  char command[SMTP_STRING_SIZE];
+  char * user64, * pass64;
+  
+  user64 = NULL;
+  pass64 = NULL;
+  
+  user64 = encode_base64(user, strlen(user));
+  if (user64 == NULL) {
+    err = MAILSMTP_ERROR_MEMORY;
+    goto err_free;
+  }
+  
+  pass64 = encode_base64(pass, strlen(pass));
+  if (pass64 == NULL) {
+    err = MAILSMTP_ERROR_MEMORY;
+    goto err_free;
+  }
+  
+  snprintf(command, SMTP_STRING_SIZE, "%s\r\n", user64);
+  err = send_command(session, command);
+  if (err == -1) {
+    err = MAILSMTP_ERROR_STREAM;
+    goto err_free;
+  }
+  err = read_response(session);
+  err = auth_map_errors(err);
+  if (err != MAILSMTP_NO_ERROR)
+    goto err_free;
+  
+  snprintf(command, SMTP_STRING_SIZE, "%s\r\n", pass64);
+  err = send_command(session, command);
+  if (err == -1) {
+    err = MAILSMTP_ERROR_STREAM;
+    goto err_free;
+  }
+  err = read_response(session);
+  err = auth_map_errors(err);
+  
+ err_free:
+  free(user64);
+  free(pass64);
+  
+  return err;
+}
+
+static int mailsmtp_auth_plain(mailsmtp * session,
+    const char * user, const char * pass)
+{
+  int err, len;
+  char command[SMTP_STRING_SIZE];
+  char * plain, * plain64;
+
+  len = strlen(user) + strlen(pass) + 3;
+  plain = (char *) malloc(len);
+  if (plain == NULL) {
+    err = MAILSMTP_ERROR_MEMORY;
+    goto err;
+  }
+  
+  snprintf(plain, len, "%c%s%c%s", '\0', user, '\0', pass);
+  plain64 = encode_base64(plain, len - 1);
+
+  snprintf(command, SMTP_STRING_SIZE, "%s\r\n", plain64);
+  err = send_command(session, command);
+  if (err == -1) {
+    err = MAILSMTP_ERROR_STREAM;
+    goto err_free;
+  }
+
+  err = read_response(session);
+  err = auth_map_errors(err);
+  
+err_free:
+  free(plain64);
+  free(plain);
+
+ err:
+  return err;
+}
+
+static char * convert_hex(unsigned char *in, int len)
+{
+  static char hex[] = "0123456789abcdef";
+  char * out;
+  int i;
+
+  out = (char *) malloc(len * 2 + 1);
+  if (out == NULL)
+    return NULL;
+
+  for (i = 0; i < len; i++) {
+    out[i * 2] = hex[in[i] >> 4];
+    out[i * 2 + 1] = hex[in[i] & 15];
+  }
+
+  out[i*2] = 0;
+  
+  return out;
+}
+
+static char * hash_md5(const char * sec_key, const char * data, int len)
+{
+  char key[65], digest[24];
+  char * hash_hex;
+  
+  int sec_len, i;
+
+  sec_len = strlen(sec_key);
+  
+  if (sec_len < 64) {
+    memcpy(key, sec_key, sec_len);      
+    for (i = sec_len; i < 64; i++) {
+      key[i] = 0;
+    }
+  } else {
+    memcpy(key, sec_key, 64);      
+  }
+
+  hmac_md5(data, len, key, 64, digest);
+  hash_hex = convert_hex(digest, 16);
+
+  return hash_hex;
+}
+
+static int mailsmtp_auth_cram_md5(mailsmtp * session,
+    const char * user, const char * pass)
+{
+  int err;
+  char command[SMTP_STRING_SIZE];
+  char *response, *auth_hex, *auth;
+  
+  response = decode_base64(session->response, strlen(session->response));
+  if (response == NULL) return MAILSMTP_ERROR_MEMORY;
+  
+  auth_hex = hash_md5(pass, response, strlen(response));
+  if (auth_hex == NULL) {
+    err = MAILSMTP_ERROR_MEMORY;
+    goto err_free_response;
+  }
+  
+  snprintf(command, SMTP_STRING_SIZE, "%s %s", user, auth_hex);
+  
+  auth = encode_base64(command, strlen(command));
+  if (auth == NULL) {
+    err = MAILSMTP_ERROR_MEMORY;
+    goto err_free_auth_hex;
+  }
+
+  snprintf(command, SMTP_STRING_SIZE, "%s\r\n", auth);
+  err = send_command(session, command);
+  if (err == -1) {
+    err = MAILSMTP_ERROR_STREAM;
+    goto err_free;
+  }
+
+  err = read_response(session);
+  err = auth_map_errors(err);
+  
+err_free:  
+  free(auth);
+err_free_auth_hex:
+  free(auth_hex);
+err_free_response:
+  free(response);
+  return err;
+}
+
+int mailsmtp_auth_type(mailsmtp * session,
+    const char * user, const char * pass, int type)
+{
+  int err;
+  char command[SMTP_STRING_SIZE];
+  
+  if (session->auth == MAILSMTP_AUTH_NOT_CHECKED) 
+    return MAILSMTP_ERROR_BAD_SEQUENCE_OF_COMMAND;
+    
+  if ( !(session->auth & type) ) return MAILSMTP_ERROR_AUTH_NOT_SUPPORTED;
+  
+  switch (type) {
+  case MAILSMTP_AUTH_LOGIN:
+    snprintf(command, SMTP_STRING_SIZE, "AUTH LOGIN\r\n");
+    break;
+  case MAILSMTP_AUTH_PLAIN:
+    snprintf(command, SMTP_STRING_SIZE, "AUTH PLAIN\r\n");
+    break;
+  case MAILSMTP_AUTH_CRAM_MD5:
+    snprintf(command, SMTP_STRING_SIZE, "AUTH CRAM-MD5\r\n");
+    break;
+  default:
+    return MAILSMTP_ERROR_NOT_IMPLEMENTED;
+  }
+  
+  err = send_command(session, command);
+  if (err == -1) return MAILSMTP_ERROR_STREAM;
+
+  err = read_response(session);
+  err = auth_map_errors(err);
+  if (err != MAILSMTP_NO_ERROR) return err;
+  
+  switch (type) {
+  case MAILSMTP_AUTH_LOGIN:
+    return mailsmtp_auth_login(session, user, pass);
+  case MAILSMTP_AUTH_PLAIN:
+    return mailsmtp_auth_plain(session, user, pass);
+  case MAILSMTP_AUTH_CRAM_MD5:
+    return mailsmtp_auth_cram_md5(session, user, pass);
+  default:
+    return MAILSMTP_ERROR_NOT_IMPLEMENTED;
+  }
+}
+
+
+int mailsmtp_auth(mailsmtp * session, const char * user, const char * pass)
+{
+  if (session->auth == MAILSMTP_AUTH_NOT_CHECKED) 
+    return MAILSMTP_ERROR_BAD_SEQUENCE_OF_COMMAND;
+    
+  if (session->auth & MAILSMTP_AUTH_CRAM_MD5) {
+    return mailsmtp_auth_type(session, user, pass, MAILSMTP_AUTH_CRAM_MD5);
+  } else if (session->auth & MAILSMTP_AUTH_PLAIN) {
+    return mailsmtp_auth_type(session, user, pass, MAILSMTP_AUTH_PLAIN);
+  } else if (session->auth & MAILSMTP_AUTH_LOGIN) {
+    return mailsmtp_auth_type(session, user, pass, MAILSMTP_AUTH_LOGIN);
+  } else {
+    return MAILSMTP_ERROR_AUTH_NOT_SUPPORTED;
+  }
+}
+
+/* TODO: add mailesmtp_etrn, mailssmtp_expn */
+
+int mailesmtp_starttls(mailsmtp * session) {
+  int r;
+
+  if (!(session->esmtp & MAILSMTP_ESMTP_STARTTLS))
+    return MAILSMTP_ERROR_STARTTLS_NOT_SUPPORTED;
+
+  r = send_command(session, "STARTTLS\r\n");
+  if (r == -1)
+    return MAILSMTP_ERROR_STREAM;
+  r = read_response(session);
+
+  switch (r) {
+  case 220:
+    return MAILSMTP_NO_ERROR;
+
+  case 454:
+    return MAILSMTP_ERROR_STARTTLS_TEMPORARY_FAILURE;
+
+  default:
+    return MAILSMTP_ERROR_UNEXPECTED_CODE;
+  }
+}
+
+static int parse_response(mailsmtp * session,
+			   char * response)
+{
+  char * message;
+  int code;
+  int cont = 0;
+
+  code = strtol(response, &message, 10);
+  if (* message == ' ')
+    mmap_string_append(session->response_buffer, message + 1);
+  else if (* message == '-') {
+    cont = SMTP_STATUS_CONTINUE;
+    mmap_string_append(session->response_buffer, message + 1);
+  }
+  else
+    mmap_string_append(session->response_buffer, message);
+      
+  return code | cont;
+}
+
+static char * read_line(mailsmtp * session)
+{
+  return mailstream_read_line_remove_eol(session->stream,
+					 session->line_buffer);
+}
+
+static int read_response(mailsmtp * session)
+{
+  char * line;
+  int code;
+
+  mmap_string_assign(session->response_buffer, "");
+
+  do {
+    line = read_line(session);
+
+    if (line != NULL) {
+	code = parse_response(session, line);
+        mmap_string_append_c(session->response_buffer, '\n');
+      }
+    else
+      code = 0;
+  }
+  while ((code & SMTP_STATUS_CONTINUE) != 0);
+
+  session->response = session->response_buffer->str;
+
+  return code;
+}
+
+
+
+
+
+static int send_command(mailsmtp * f, char * command)
+{
+  ssize_t r;
+
+  r = mailstream_write(f->stream, command, strlen(command));
+  if (r == -1)
+    return -1;
+
+  r = mailstream_flush(f->stream);
+  if (r == -1)
+    return -1;
+
+  return 0;
+}
+
+static int send_data(mailsmtp * session, const char * message, size_t size)
+{
+  if (mailstream_send_data(session->stream, message, size,
+			   session->progr_rate, session->progr_fun) == -1)
+    return -1;
+
+  if (mailstream_flush(session->stream) == -1)
+    return -1;
+
+  return 0;
+}
+
+
+const char * mailsmtp_strerror(int errnum)
+{
+  switch (errnum)    {
+  case MAILSMTP_NO_ERROR:
+    return "No error";
+  case MAILSMTP_ERROR_UNEXPECTED_CODE:
+    return "Unexpected error code";
+  case MAILSMTP_ERROR_SERVICE_NOT_AVAILABLE:
+    return "Service not available";
+  case MAILSMTP_ERROR_STREAM:
+    return "Stream error";
+  case MAILSMTP_ERROR_HOSTNAME:
+    return "gethostname() failed";
+  case MAILSMTP_ERROR_NOT_IMPLEMENTED:
+    return "Not implemented";
+  case MAILSMTP_ERROR_ACTION_NOT_TAKEN:
+    return "Error, action not taken";
+  case MAILSMTP_ERROR_EXCEED_STORAGE_ALLOCATION:
+    return "Data exceeds storage allocation";
+  case MAILSMTP_ERROR_IN_PROCESSING:
+    return "Error in processing";
+  case MAILSMTP_ERROR_INSUFFICIENT_SYSTEM_STORAGE:
+    return "Insufficient system storage";
+  case MAILSMTP_ERROR_MAILBOX_UNAVAILABLE:
+    return "Mailbox unavailable";
+  case MAILSMTP_ERROR_MAILBOX_NAME_NOT_ALLOWED:
+    return "Mailbox name not allowed";
+  case MAILSMTP_ERROR_BAD_SEQUENCE_OF_COMMAND:
+    return "Bad command sequence";
+  case MAILSMTP_ERROR_USER_NOT_LOCAL:
+    return "User not local";
+  case MAILSMTP_ERROR_TRANSACTION_FAILED:
+    return "Transaction failed";
+  case MAILSMTP_ERROR_MEMORY:
+    return "Memory error";
+  case MAILSMTP_ERROR_CONNECTION_REFUSED:
+    return "Connection refused";
+  case MAILSMTP_ERROR_STARTTLS_TEMPORARY_FAILURE:
+    return "TLS not available on server for temporary reason";
+  case MAILSMTP_ERROR_STARTTLS_NOT_SUPPORTED:
+    return "TLS not supported by server";
+  default:
+    return "Unknown error code";
+  }
+}