Commit message: imap: if a FETCH response has no size, don't call write callback

CVE-2017-1000257

Reported-by: Brian Carpenter and 0xd34db347
Also detected by OSS-Fuzz: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3586
CVE: CVE-2017-1000257
CWE: CWE-119
Vulnerability description: An IMAP FETCH response line indicates the size of the returned data, in number of bytes. When that response says the data is zero bytes, libcurl would pass on that (non-existing) data with a pointer and the size (zero) to the deliver-data function. libcurl's deliver-data function treats zero as a magic number and invokes strlen() on the data to figure out the length. The strlen() is called on a heap based buffer that might not be zero terminated so libcurl might read beyond the end of it into whatever memory lies after (or just crash) and then deliver that to the application as if it was actually downloaded.

Project: curl
File: imap.c

static CURLcode imap_state_auth_resp(struct connectdata *conn,
                                     int imapcode,
                                     imapstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct imap_conn *imapc = &conn->proto.imapc;
  saslprogress progress;

  (void)instate; /* no use for this yet */

  result = Curl_sasl_continue(&imapc->sasl, conn, imapcode, &progress);
  if(!result)
    switch(progress) {
    case SASL_DONE:
      state(conn, IMAP_STOP);  /* Authenticated */
      break;
    case SASL_IDLE:            /* No mechanism left after cancellation */
      if((!imapc->login_disabled) && (imapc->preftype & IMAP_TYPE_CLEARTEXT))
        /* Perform clear text authentication */
        result = imap_perform_login(conn);
      else {
        failf(data, "Authentication cancelled");
        result = CURLE_LOGIN_DENIED;
      }
      break;
    default:
      break;
    }

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_done(struct connectdata *conn, CURLcode status,
                          bool premature)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = data->req.protop;

  (void)premature;

  if(!imap)
    return CURLE_OK;

  if(status) {
    connclose(conn, "IMAP done with bad status"); /* marked for closure */
    result = status;         /* use the already set error code */
  }
  else if(!data->set.connect_only && !imap->custom &&
          (imap->uid || data->set.upload ||
          data->set.mimepost.kind != MIMEKIND_NONE)) {
    /* Handle responses after FETCH or APPEND transfer has finished */
    if(!data->set.upload && data->set.mimepost.kind == MIMEKIND_NONE)
      state(conn, IMAP_FETCH_FINAL);
    else {
      /* End the APPEND command first by sending an empty line */
      result = Curl_pp_sendf(&conn->proto.imapc.pp, "%s", "");
      if(!result)
        state(conn, IMAP_APPEND_FINAL);
    }

    /* Run the state-machine

       TODO: when the multi interface is used, this _really_ should be using
       the imap_multi_statemach function but we have no general support for
       non-blocking DONE operations!
    */
    if(!result)
      result = imap_block_statemach(conn);
  }

  /* Cleanup our per-request based variables */
  Curl_safefree(imap->mailbox);
  Curl_safefree(imap->uidvalidity);
  Curl_safefree(imap->uid);
  Curl_safefree(imap->section);
  Curl_safefree(imap->partial);
  Curl_safefree(imap->query);
  Curl_safefree(imap->custom);
  Curl_safefree(imap->custom_params);

  /* Clear the transfer mode for the next request */
  imap->transfer = FTPTRANSFER_BODY;

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_state_login_resp(struct connectdata *conn,
                                      int imapcode,
                                      imapstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;

  (void)instate; /* no use for this yet */

  if(imapcode != IMAP_RESP_OK) {
    failf(data, "Access denied. %c", imapcode);
    result = CURLE_LOGIN_DENIED;
  }
  else
    /* End of connect phase */
    state(conn, IMAP_STOP);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_list(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = data->req.protop;
  char *mailbox;

  if(imap->custom)
    /* Send the custom request */
    result = imap_sendf(conn, "%s%s", imap->custom,
                        imap->custom_params ? imap->custom_params : "");
  else {
    /* Make sure the mailbox is in the correct atom format if necessary */
    mailbox = imap->mailbox ? imap_atom(imap->mailbox, true) : strdup("");
    if(!mailbox)
      return CURLE_OUT_OF_MEMORY;

    /* Send the LIST command */
    result = imap_sendf(conn, "LIST \"%s\" *", mailbox);

    free(mailbox);
  }

  if(!result)
    state(conn, IMAP_LIST);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_setup_connection(struct connectdata *conn)
{
  struct Curl_easy *data = conn->data;

  /* Initialise the IMAP layer */
  CURLcode result = imap_init(conn);
  if(result)
    return result;

  /* Clear the TLS upgraded flag */
  conn->tls_upgraded = FALSE;
  data->state.path++;   /* don't include the initial slash */

  return CURLE_OK;
}

Project: curl
File: imap.c

static bool imap_endofresp(struct connectdata *conn, char *line, size_t len,
                           int *resp)
{
  struct IMAP *imap = conn->data->req.protop;
  struct imap_conn *imapc = &conn->proto.imapc;
  const char *id = imapc->resptag;
  size_t id_len = strlen(id);

  /* Do we have a tagged command response? */
  if(len >= id_len + 1 && !memcmp(id, line, id_len) && line[id_len] == ' ') {
    line += id_len + 1;
    len -= id_len + 1;

    if(len >= 2 && !memcmp(line, "OK", 2))
      *resp = IMAP_RESP_OK;
    else if(len >= 7 && !memcmp(line, "PREAUTH", 7))
      *resp = IMAP_RESP_PREAUTH;
    else
      *resp = IMAP_RESP_NOT_OK;

    return TRUE;
  }

  /* Do we have an untagged command response? */
  if(len >= 2 && !memcmp("* ", line, 2)) {
    switch(imapc->state) {
      /* States which are interested in untagged responses */
      case IMAP_CAPABILITY:
        if(!imap_matchresp(line, len, "CAPABILITY"))
          return FALSE;
        break;

      case IMAP_LIST:
        if((!imap->custom && !imap_matchresp(line, len, "LIST")) ||
          (imap->custom && !imap_matchresp(line, len, imap->custom) &&
           (strcmp(imap->custom, "STORE") ||
            !imap_matchresp(line, len, "FETCH")) &&
           strcmp(imap->custom, "SELECT") &&
           strcmp(imap->custom, "EXAMINE") &&
           strcmp(imap->custom, "SEARCH") &&
           strcmp(imap->custom, "EXPUNGE") &&
           strcmp(imap->custom, "LSUB") &&
           strcmp(imap->custom, "UID") &&
           strcmp(imap->custom, "NOOP")))
          return FALSE;
        break;

      case IMAP_SELECT:
        /* SELECT is special in that its untagged responses do not have a
           common prefix so accept anything! */
        break;

      case IMAP_FETCH:
        if(!imap_matchresp(line, len, "FETCH"))
          return FALSE;
        break;

      case IMAP_SEARCH:
        if(!imap_matchresp(line, len, "SEARCH"))
          return FALSE;
        break;

      /* Ignore other untagged responses */
      default:
        return FALSE;
    }

    *resp = '*';
    return TRUE;
  }

  /* Do we have a continuation response? This should be a + symbol followed by
     a space and optionally some text as per RFC-3501 for the AUTHENTICATE and
     APPEND commands and as outlined in Section 4. Examples of RFC-4959 but
     some e-mail servers ignore this and only send a single + instead. */
  if(imap && !imap->custom && ((len == 3 && !memcmp("+", line, 1)) ||
     (len >= 2 && !memcmp("+ ", line, 2)))) {
    switch(imapc->state) {
      /* States which are interested in continuation responses */
      case IMAP_AUTHENTICATE:
      case IMAP_APPEND:
        *resp = '+';
        break;

      default:
        failf(conn->data, "Unexpected continuation response");
        *resp = -1;
        break;
    }

    return TRUE;
  }

  return FALSE; /* Nothing for us */
}

Project: curl
File: imap.c

static CURLcode imap_state_fetch_final_resp(struct connectdata *conn,
                                            int imapcode,
                                            imapstate instate)
{
  CURLcode result = CURLE_OK;

  (void)instate; /* No use for this yet */

  if(imapcode != IMAP_RESP_OK)
    result = CURLE_WEIRD_SERVER_REPLY;
  else
    /* End of DONE phase */
    state(conn, IMAP_STOP);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_select(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = data->req.protop;
  struct imap_conn *imapc = &conn->proto.imapc;
  char *mailbox;

  /* Invalidate old information as we are switching mailboxes */
  Curl_safefree(imapc->mailbox);
  Curl_safefree(imapc->mailbox_uidvalidity);

  /* Check we have a mailbox */
  if(!imap->mailbox) {
    failf(conn->data, "Cannot SELECT without a mailbox.");
    return CURLE_URL_MALFORMAT;
  }

  /* Make sure the mailbox is in the correct atom format */
  mailbox = imap_atom(imap->mailbox, false);
  if(!mailbox)
    return CURLE_OUT_OF_MEMORY;

  /* Send the SELECT command */
  result = imap_sendf(conn, "SELECT %s", mailbox);

  free(mailbox);

  if(!result)
    state(conn, IMAP_SELECT);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_block_statemach(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;

  while(imapc->state != IMAP_STOP && !result)
    result = Curl_pp_statemach(&imapc->pp, TRUE);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_state_select_resp(struct connectdata *conn, int imapcode,
                                       imapstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = conn->data->req.protop;
  struct imap_conn *imapc = &conn->proto.imapc;
  const char *line = data->state.buffer;
  char tmp[20];

  (void)instate; /* no use for this yet */

  if(imapcode == '*') {
    /* See if this is an UIDVALIDITY response */
    if(sscanf(line + 2, "OK [UIDVALIDITY %19[0123456789]]", tmp) == 1) {
      Curl_safefree(imapc->mailbox_uidvalidity);
      imapc->mailbox_uidvalidity = strdup(tmp);
    }
  }
  else if(imapcode == IMAP_RESP_OK) {
    /* Check if the UIDVALIDITY has been specified and matches */
    if(imap->uidvalidity && imapc->mailbox_uidvalidity &&
       strcmp(imap->uidvalidity, imapc->mailbox_uidvalidity)) {
      failf(conn->data, "Mailbox UIDVALIDITY has changed");
      result = CURLE_REMOTE_FILE_NOT_FOUND;
    }
    else {
      /* Note the currently opened mailbox on this connection */
      imapc->mailbox = strdup(imap->mailbox);

      if(imap->custom)
        result = imap_perform_list(conn);
      else if(imap->query)
        result = imap_perform_search(conn);
      else
        result = imap_perform_fetch(conn);
    }
  }
  else {
    failf(data, "Select failed");
    result = CURLE_LOGIN_DENIED;
  }

  return result;
}

Project: curl
File: imap.c

static int imap_getsock(struct connectdata *conn, curl_socket_t *socks,
                        int numsocks)
{
  return Curl_pp_getsock(&conn->proto.imapc.pp, socks, numsocks);
}

Project: curl
File: imap.c

static CURLcode imap_parse_custom_request(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = data->req.protop;
  const char *custom = data->set.str[STRING_CUSTOMREQUEST];

  if(custom) {
    /* URL decode the custom request */
    result = Curl_urldecode(data, custom, 0, &imap->custom, NULL, TRUE);

    /* Extract the parameters if specified */
    if(!result) {
      const char *params = imap->custom;

      while(*params && *params != ' ')
        params++;

      if(*params) {
        imap->custom_params = strdup(params);
        imap->custom[params - imap->custom] = '\0';

        if(!imap->custom_params)
          result = CURLE_OUT_OF_MEMORY;
      }
    }
  }

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_login(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  char *user;
  char *passwd;

  /* Check we have a username and password to authenticate with and end the
     connect phase if we don't */
  if(!conn->bits.user_passwd) {
    state(conn, IMAP_STOP);

    return result;
  }

  /* Make sure the username and password are in the correct atom format */
  user = imap_atom(conn->user, false);
  passwd = imap_atom(conn->passwd, false);

  /* Send the LOGIN command */
  result = imap_sendf(conn, "LOGIN %s %s", user ? user : "",
                      passwd ? passwd : "");

  free(user);
  free(passwd);

  if(!result)
    state(conn, IMAP_LOGIN);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_multi_statemach(struct connectdata *conn, bool *done)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;

  if((conn->handler->flags & PROTOPT_SSL) && !imapc->ssldone) {
    result = Curl_ssl_connect_nonblocking(conn, FIRSTSOCKET, &imapc->ssldone);
    if(result || !imapc->ssldone)
      return result;
  }

  result = Curl_pp_statemach(&imapc->pp, FALSE);
  *done = (imapc->state == IMAP_STOP) ? TRUE : FALSE;

  return result;
}

Project: curl
File: imap.c

static bool imap_is_bchar(char ch)
{
  switch(ch) {
    /* bchar */
    case ':': case '@': case '/':
    /* bchar -> achar */
    case '&': case '=':
    /* bchar -> achar -> uchar -> unreserved */
    case '0': case '1': case '2': case '3': case '4': case '5': case '6':
    case '7': case '8': case '9':
    case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':
    case 'H': case 'I': case 'J': case 'K': case 'L': case 'M': case 'N':
    case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U':
    case 'V': case 'W': case 'X': case 'Y': case 'Z':
    case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
    case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
    case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
    case 'v': case 'w': case 'x': case 'y': case 'z':
    case '-': case '.': case '_': case '~':
    /* bchar -> achar -> uchar -> sub-delims-sh */
    case '!': case '$': case '\'': case '(': case ')': case '*':
    case '+': case ',':
    /* bchar -> achar -> uchar -> pct-encoded */
    case '%': /* HEXDIG chars are already included above */
      return true;

    default:
      return false;
  }
}

Project: curl
File: imap.c

static CURLcode imap_state_capability_resp(struct connectdata *conn,
                                           int imapcode,
                                           imapstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct imap_conn *imapc = &conn->proto.imapc;
  const char *line = data->state.buffer;
  size_t wordlen;

  (void)instate; /* no use for this yet */

  /* Do we have a untagged response? */
  if(imapcode == '*') {
    line += 2;

    /* Loop through the data line */
    for(;;) {
      while(*line &&
            (*line == ' ' || *line == '\t' ||
              *line == '\r' || *line == '\n')) {

        line++;
      }

      if(!*line)
        break;

      /* Extract the word */
      for(wordlen = 0; line[wordlen] && line[wordlen] != ' ' &&
            line[wordlen] != '\t' && line[wordlen] != '\r' &&
            line[wordlen] != '\n';)
        wordlen++;

      /* Does the server support the STARTTLS capability? */
      if(wordlen == 8 && !memcmp(line, "STARTTLS", 8))
        imapc->tls_supported = TRUE;

      /* Has the server explicitly disabled clear text authentication? */
      else if(wordlen == 13 && !memcmp(line, "LOGINDISABLED", 13))
        imapc->login_disabled = TRUE;

      /* Does the server support the SASL-IR capability? */
      else if(wordlen == 7 && !memcmp(line, "SASL-IR", 7))
        imapc->ir_supported = TRUE;

      /* Do we have a SASL based authentication mechanism? */
      else if(wordlen > 5 && !memcmp(line, "AUTH=", 5)) {
        size_t llen;
        unsigned int mechbit;

        line += 5;
        wordlen -= 5;

        /* Test the word for a matching authentication mechanism */
        mechbit = Curl_sasl_decode_mech(line, wordlen, &llen);
        if(mechbit && llen == wordlen)
          imapc->sasl.authmechs |= mechbit;
      }

      line += wordlen;
    }
  }
  else if(imapcode == IMAP_RESP_OK) {
    if(data->set.use_ssl && !conn->ssl[FIRSTSOCKET].use) {
      /* We don't have a SSL/TLS connection yet, but SSL is requested */
      if(imapc->tls_supported)
        /* Switch to TLS connection now */
        result = imap_perform_starttls(conn);
      else if(data->set.use_ssl == CURLUSESSL_TRY)
        /* Fallback and carry on with authentication */
        result = imap_perform_authentication(conn);
      else {
        failf(data, "STARTTLS not supported.");
        result = CURLE_USE_SSL_FAILED;
      }
    }
    else
      result = imap_perform_authentication(conn);
  }
  else
    result = imap_perform_authentication(conn);

  return result;
}

Project: curl
File: imap.c

static char *imap_atom(const char *str, bool escape_only)
{
  /* !checksrc! disable PARENBRACE 1 */
  const char atom_specials[] = "(){ %*]";
  const char *p1;
  char *p2;
  size_t backsp_count = 0;
  size_t quote_count = 0;
  bool others_exists = FALSE;
  size_t newlen = 0;
  char *newstr = NULL;

  if(!str)
    return NULL;

  /* Look for "atom-specials", counting the backslash and quote characters as
     these will need escapping */
  p1 = str;
  while(*p1) {
    if(*p1 == '\\')
      backsp_count++;
    else if(*p1 == '"')
      quote_count++;
    else if(!escape_only) {
      const char *p3 = atom_specials;

      while(*p3 && !others_exists) {
        if(*p1 == *p3)
          others_exists = TRUE;

        p3++;
      }
    }

    p1++;
  }

  /* Does the input contain any "atom-special" characters? */
  if(!backsp_count && !quote_count && !others_exists)
    return strdup(str);

  /* Calculate the new string length */
  newlen = strlen(str) + backsp_count + quote_count + (escape_only ? 0 : 2);

  /* Allocate the new string */
  newstr = (char *) malloc((newlen + 1) * sizeof(char));
  if(!newstr)
    return NULL;

  /* Surround the string in quotes if necessary */
  p2 = newstr;
  if(!escape_only) {
    newstr[0] = '"';
    newstr[newlen - 1] = '"';
    p2++;
  }

  /* Copy the string, escaping backslash and quote characters along the way */
  p1 = str;
  while(*p1) {
    if(*p1 == '\\' || *p1 == '"') {
      *p2 = '\\';
      p2++;
    }

   *p2 = *p1;

    p1++;
    p2++;
  }

  /* Terminate the string */
  newstr[newlen] = '\0';

  return newstr;
}

Project: curl
File: imap.c

static CURLcode imap_state_fetch_resp(struct connectdata *conn, int imapcode,
                                      imapstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct imap_conn *imapc = &conn->proto.imapc;
  struct pingpong *pp = &imapc->pp;
  const char *ptr = data->state.buffer;
  bool parsed = FALSE;
  curl_off_t size = 0;

  (void)instate; /* no use for this yet */

  if(imapcode != '*') {
    Curl_pgrsSetDownloadSize(data, -1);
    state(conn, IMAP_STOP);
    return CURLE_REMOTE_FILE_NOT_FOUND; /* TODO: Fix error code */
  }

  /* Something like this is received "* 1 FETCH (BODY[TEXT] {2021}\r" so parse
     the continuation data contained within the curly brackets */
  while(*ptr && (*ptr != '{'))
    ptr++;

  if(*ptr == '{') {
    char *endptr;
    if(!curlx_strtoofft(ptr + 1, &endptr, 10, &size)) {
      if(endptr - ptr > 1 && endptr[0] == '}' &&
         endptr[1] == '\r' && endptr[2] == '\0')
        parsed = TRUE;
    }
  }

  if(parsed) {
    infof(data, "Found %" CURL_FORMAT_CURL_OFF_TU " bytes to download\n",
          size);
    Curl_pgrsSetDownloadSize(data, size);

    if(pp->cache) {
      /* At this point there is a bunch of data in the header "cache" that is
         actually body content, send it as body and then skip it. Do note
         that there may even be additional "headers" after the body. */
      size_t chunk = pp->cache_size;

      if(chunk > (size_t)size)
        /* The conversion from curl_off_t to size_t is always fine here */
        chunk = (size_t)size;

      if(!chunk) {
        /* no size, we're done with the data */
        state(conn, IMAP_STOP);
        return CURLE_OK;
      }
      result = Curl_client_write(conn, CLIENTWRITE_BODY, pp->cache, chunk);
      if(result)
        return result;

      data->req.bytecount += chunk;

      infof(data, "Written %" CURL_FORMAT_CURL_OFF_TU
            " bytes, %" CURL_FORMAT_CURL_OFF_TU
            " bytes are left for transfer\n", (curl_off_t)chunk,
            size - chunk);

      /* Have we used the entire cache or just part of it?*/
      if(pp->cache_size > chunk) {
        /* Only part of it so shrink the cache to fit the trailing data */
        memmove(pp->cache, pp->cache + chunk, pp->cache_size - chunk);
        pp->cache_size -= chunk;
      }
      else {
        /* Free the cache */
        Curl_safefree(pp->cache);

        /* Reset the cache size */
        pp->cache_size = 0;
      }
    }

    if(data->req.bytecount == size)
      /* The entire data is already transferred! */
      Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
    else {
      /* IMAP download */
      data->req.maxdownload = size;
      Curl_setup_transfer(conn, FIRSTSOCKET, size, FALSE, NULL, -1, NULL);
    }
  }
  else {
    /* We don't know how to parse this line */
    failf(pp->conn->data, "Failed to parse FETCH response.");
    result = CURLE_WEIRD_SERVER_REPLY;
  }

  /* End of DO phase */
  state(conn, IMAP_STOP);

  return result;
}

Project: curl
File: imap.c

static void imap_to_imaps(struct connectdata *conn)
{
  /* Change the connection handler */
  conn->handler = &Curl_handler_imaps;

  /* Set the connection's upgraded to TLS flag */
  conn->tls_upgraded = TRUE;
}

Project: curl
File: imap.c

static CURLcode imap_perform_search(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct IMAP *imap = conn->data->req.protop;

  /* Check we have a query string */
  if(!imap->query) {
    failf(conn->data, "Cannot SEARCH without a query string.");
    return CURLE_URL_MALFORMAT;
  }

  /* Send the SEARCH command */
  result = imap_sendf(conn, "SEARCH %s", imap->query);

  if(!result)
    state(conn, IMAP_SEARCH);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_state_append_final_resp(struct connectdata *conn,
                                             int imapcode,
                                             imapstate instate)
{
  CURLcode result = CURLE_OK;

  (void)instate; /* No use for this yet */

  if(imapcode != IMAP_RESP_OK)
    result = CURLE_UPLOAD_FAILED;
  else
    /* End of DONE phase */
    state(conn, IMAP_STOP);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_fetch(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct IMAP *imap = conn->data->req.protop;

  /* Check we have a UID */
  if(!imap->uid) {
    failf(conn->data, "Cannot FETCH without a UID.");
    return CURLE_URL_MALFORMAT;
  }

  /* Send the FETCH command */
  if(imap->partial)
    result = imap_sendf(conn, "FETCH %s BODY[%s]<%s>",
                        imap->uid,
                        imap->section ? imap->section : "",
                        imap->partial);
  else
    result = imap_sendf(conn, "FETCH %s BODY[%s]",
                        imap->uid,
                        imap->section ? imap->section : "");

  if(!result)
    state(conn, IMAP_FETCH);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_parse_url_path(struct connectdata *conn)
{
  /* The imap struct is already initialised in imap_connect() */
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = data->req.protop;
  const char *begin = data->state.path;
  const char *ptr = begin;

  /* See how much of the URL is a valid path and decode it */
  while(imap_is_bchar(*ptr))
    ptr++;

  if(ptr != begin) {
    /* Remove the trailing slash if present */
    const char *end = ptr;
    if(end > begin && end[-1] == '/')
      end--;

    result = Curl_urldecode(data, begin, end - begin, &imap->mailbox, NULL,
                            TRUE);
    if(result)
      return result;
  }
  else
    imap->mailbox = NULL;

  /* There can be any number of parameters in the form ";NAME=VALUE" */
  while(*ptr == ';') {
    char *name;
    char *value;
    size_t valuelen;

    /* Find the length of the name parameter */
    begin = ++ptr;
    while(*ptr && *ptr != '=')
      ptr++;

    if(!*ptr)
      return CURLE_URL_MALFORMAT;

    /* Decode the name parameter */
    result = Curl_urldecode(data, begin, ptr - begin, &name, NULL, TRUE);
    if(result)
      return result;

    /* Find the length of the value parameter */
    begin = ++ptr;
    while(imap_is_bchar(*ptr))
      ptr++;

    /* Decode the value parameter */
    result = Curl_urldecode(data, begin, ptr - begin, &value, &valuelen, TRUE);
    if(result) {
      free(name);
      return result;
    }

    DEBUGF(infof(conn->data, "IMAP URL parameter '%s' = '%s'\n", name, value));

    /* Process the known hierarchical parameters (UIDVALIDITY, UID, SECTION and
       PARTIAL) stripping of the trailing slash character if it is present.

       Note: Unknown parameters trigger a URL_MALFORMAT error. */
    if(strcasecompare(name, "UIDVALIDITY") && !imap->uidvalidity) {
      if(valuelen > 0 && value[valuelen - 1] == '/')
        value[valuelen - 1] = '\0';

      imap->uidvalidity = value;
      value = NULL;
    }
    else if(strcasecompare(name, "UID") && !imap->uid) {
      if(valuelen > 0 && value[valuelen - 1] == '/')
        value[valuelen - 1] = '\0';

      imap->uid = value;
      value = NULL;
    }
    else if(strcasecompare(name, "SECTION") && !imap->section) {
      if(valuelen > 0 && value[valuelen - 1] == '/')
        value[valuelen - 1] = '\0';

      imap->section = value;
      value = NULL;
    }
    else if(strcasecompare(name, "PARTIAL") && !imap->partial) {
      if(valuelen > 0 && value[valuelen - 1] == '/')
        value[valuelen - 1] = '\0';

      imap->partial = value;
      value = NULL;
    }
    else {
      free(name);
      free(value);

      return CURLE_URL_MALFORMAT;
    }

    free(name);
    free(value);
  }

  /* Does the URL contain a query parameter? Only valid when we have a mailbox
     and no UID as per RFC-5092 */
  if(imap->mailbox && !imap->uid && *ptr == '?') {
    /* Find the length of the query parameter */
    begin = ++ptr;
    while(imap_is_bchar(*ptr))
      ptr++;

    /* Decode the query parameter */
    result = Curl_urldecode(data, begin, ptr - begin, &imap->query, NULL,
                            TRUE);
    if(result)
      return result;
  }

  /* Any extra stuff at the end of the URL is an error */
  if(*ptr)
    return CURLE_URL_MALFORMAT;

  return CURLE_OK;
}

Project: curl
File: imap.c

static CURLcode imap_state_starttls_resp(struct connectdata *conn,
                                         int imapcode,
                                         imapstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;

  (void)instate; /* no use for this yet */

  if(imapcode != IMAP_RESP_OK) {
    if(data->set.use_ssl != CURLUSESSL_TRY) {
      failf(data, "STARTTLS denied");
      result = CURLE_USE_SSL_FAILED;
    }
    else
      result = imap_perform_authentication(conn);
  }
  else
    result = imap_perform_upgrade_tls(conn);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_append(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = data->req.protop;
  char *mailbox;

  /* Check we have a mailbox */
  if(!imap->mailbox) {
    failf(data, "Cannot APPEND without a mailbox.");
    return CURLE_URL_MALFORMAT;
  }

  /* Prepare the mime data if some. */
  if(data->set.mimepost.kind != MIMEKIND_NONE) {
    /* Use the whole structure as data. */
    data->set.mimepost.flags &= ~MIME_BODY_ONLY;

    /* Add external headers and mime version. */
    curl_mime_headers(&data->set.mimepost, data->set.headers, 0);
    result = Curl_mime_prepare_headers(&data->set.mimepost, NULL,
                                       NULL, MIMESTRATEGY_MAIL);

    if(!result)
      if(!Curl_checkheaders(conn, "Mime-Version"))
        result = Curl_mime_add_header(&data->set.mimepost.curlheaders,
                                      "Mime-Version: 1.0");

    /* Make sure we will read the entire mime structure. */
    if(!result)
      result = Curl_mime_rewind(&data->set.mimepost);

    if(result)
      return result;

    data->state.infilesize = Curl_mime_size(&data->set.mimepost);

    /* Read from mime structure. */
    data->state.fread_func = (curl_read_callback) Curl_mime_read;
    data->state.in = (void *) &data->set.mimepost;
  }

  /* Check we know the size of the upload */
  if(data->state.infilesize < 0) {
    failf(data, "Cannot APPEND with unknown input file size\n");
    return CURLE_UPLOAD_FAILED;
  }

  /* Make sure the mailbox is in the correct atom format */
  mailbox = imap_atom(imap->mailbox, false);
  if(!mailbox)
    return CURLE_OUT_OF_MEMORY;

  /* Send the APPEND command */
  result = imap_sendf(conn, "APPEND %s (\\Seen) {%" CURL_FORMAT_CURL_OFF_T "}",
                      mailbox, data->state.infilesize);

  free(mailbox);

  if(!result)
    state(conn, IMAP_APPEND);

  return result;
}

Project: curl
File: imap.c

static void state(struct connectdata *conn, imapstate newstate)
{
  struct imap_conn *imapc = &conn->proto.imapc;
#if defined(DEBUGBUILD) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
  /* for debug purposes */
  static const char * const names[]={
    "STOP",
    "SERVERGREET",
    "CAPABILITY",
    "STARTTLS",
    "UPGRADETLS",
    "AUTHENTICATE",
    "LOGIN",
    "LIST",
    "SELECT",
    "FETCH",
    "FETCH_FINAL",
    "APPEND",
    "APPEND_FINAL",
    "SEARCH",
    "LOGOUT",
    /* LAST */
  };

  if(imapc->state != newstate)
    infof(conn->data, "IMAP %p state change from %s to %s\n",
          (void *)imapc, names[imapc->state], names[newstate]);
#endif

  imapc->state = newstate;
}

Project: curl
File: imap.c

static void imap_get_message(char *buffer, char **outptr)
{
  size_t len = 0;
  char *message = NULL;

  /* Find the start of the message */
  for(message = buffer + 2; *message == ' ' || *message == '\t'; message++)
    ;

  /* Find the end of the message */
  for(len = strlen(message); len--;)
    if(message[len] != '\r' && message[len] != '\n' && message[len] != ' ' &&
        message[len] != '\t')
      break;

  /* Terminate the message */
  if(++len) {
    message[len] = '\0';
  }

  *outptr = message;
}

Project: curl
File: imap.c

static CURLcode imap_state_listsearch_resp(struct connectdata *conn,
                                           int imapcode,
                                           imapstate instate)
{
  CURLcode result = CURLE_OK;
  char *line = conn->data->state.buffer;
  size_t len = strlen(line);

  (void)instate; /* No use for this yet */

  if(imapcode == '*') {
    /* Temporarily add the LF character back and send as body to the client */
    line[len] = '\n';
    result = Curl_client_write(conn, CLIENTWRITE_BODY, line, len + 1);
    line[len] = '\0';
  }
  else if(imapcode != IMAP_RESP_OK)
    result = CURLE_QUOTE_ERROR; /* TODO: Fix error code */
  else
    /* End of DO phase */
    state(conn, IMAP_STOP);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_doing(struct connectdata *conn, bool *dophase_done)
{
  CURLcode result = imap_multi_statemach(conn, dophase_done);

  if(result)
    DEBUGF(infof(conn->data, "DO phase failed\n"));
  else if(*dophase_done) {
    result = imap_dophase_done(conn, FALSE /* not connected */);

    DEBUGF(infof(conn->data, "DO phase is complete\n"));
  }

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_parse_url_options(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;
  const char *ptr = conn->options;

  imapc->sasl.resetprefs = TRUE;

  while(!result && ptr && *ptr) {
    const char *key = ptr;
    const char *value;

    while(*ptr && *ptr != '=')
        ptr++;

    value = ptr + 1;

    while(*ptr && *ptr != ';')
      ptr++;

    if(strncasecompare(key, "AUTH=", 5))
      result = Curl_sasl_parse_url_auth_option(&imapc->sasl,
                                               value, ptr - value);
    else
      result = CURLE_URL_MALFORMAT;

    if(*ptr == ';')
      ptr++;
  }

  switch(imapc->sasl.prefmech) {
  case SASL_AUTH_NONE:
    imapc->preftype = IMAP_TYPE_NONE;
    break;
  case SASL_AUTH_DEFAULT:
    imapc->preftype = IMAP_TYPE_ANY;
    break;
  default:
    imapc->preftype = IMAP_TYPE_SASL;
    break;
  }

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_continue_authenticate(struct connectdata *conn,
                                           const char *resp)
{
  struct imap_conn *imapc = &conn->proto.imapc;

  return Curl_pp_sendf(&imapc->pp, "%s", resp);
}

Project: curl
File: imap.c

static CURLcode imap_connect(struct connectdata *conn, bool *done)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;
  struct pingpong *pp = &imapc->pp;

  *done = FALSE; /* default to not done yet */

  /* We always support persistent connections in IMAP */
  connkeep(conn, "IMAP default");

  /* Set the default response time-out */
  pp->response_time = RESP_TIMEOUT;
  pp->statemach_act = imap_statemach_act;
  pp->endofresp = imap_endofresp;
  pp->conn = conn;

  /* Set the default preferred authentication type and mechanism */
  imapc->preftype = IMAP_TYPE_ANY;
  Curl_sasl_init(&imapc->sasl, &saslimap);

  /* Initialise the pingpong layer */
  Curl_pp_init(pp);

  /* Parse the URL options */
  result = imap_parse_url_options(conn);
  if(result)
    return result;

  /* Start off waiting for the server greeting response */
  state(conn, IMAP_SERVERGREET);

  /* Start off with an response id of '*' */
  strcpy(imapc->resptag, "*");

  result = imap_multi_statemach(conn, done);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_disconnect(struct connectdata *conn, bool dead_connection)
{
  struct imap_conn *imapc = &conn->proto.imapc;

  /* We cannot send quit unconditionally. If this connection is stale or
     bad in any way, sending quit and waiting around here will make the
     disconnect wait in vain and cause more problems than we need to. */

  /* The IMAP session may or may not have been allocated/setup at this
     point! */
  if(!dead_connection && imapc->pp.conn && imapc->pp.conn->bits.protoconnstart)
    if(!imap_perform_logout(conn))
      (void)imap_block_statemach(conn); /* ignore errors on LOGOUT */

  /* Disconnect from the server */
  Curl_pp_disconnect(&imapc->pp);

  /* Cleanup the SASL module */
  Curl_sasl_cleanup(conn, imapc->sasl.authused);

  /* Cleanup our connection based variables */
  Curl_safefree(imapc->mailbox);
  Curl_safefree(imapc->mailbox_uidvalidity);

  return CURLE_OK;
}

Project: curl
File: imap.c

static CURLcode imap_perform_authenticate(struct connectdata *conn,
                                          const char *mech,
                                          const char *initresp)
{
  CURLcode result = CURLE_OK;

  if(initresp) {
    /* Send the AUTHENTICATE command with the initial response */
    result = imap_sendf(conn, "AUTHENTICATE %s %s", mech, initresp);
  }
  else {
    /* Send the AUTHENTICATE command */
    result = imap_sendf(conn, "AUTHENTICATE %s", mech);
  }

  return result;
}

Project: curl
File: imap.c

static bool imap_matchresp(const char *line, size_t len, const char *cmd)
{
  const char *end = line + len;
  size_t cmd_len = strlen(cmd);

  /* Skip the untagged response marker */
  line += 2;

  /* Do we have a number after the marker? */
  if(line < end && ISDIGIT(*line)) {
    /* Skip the number */
    do
      line++;
    while(line < end && ISDIGIT(*line));

    /* Do we have the space character? */
    if(line == end || *line != ' ')
      return FALSE;

    line++;
  }

  /* Does the command name match and is it followed by a space character or at
     the end of line? */
  if(line + cmd_len <= end && strncasecompare(line, cmd, cmd_len) &&
     (line[cmd_len] == ' ' || line + cmd_len + 2 == end))
    return TRUE;

  return FALSE;
}

Project: curl
File: imap.c

static CURLcode imap_dophase_done(struct connectdata *conn, bool connected)
{
  struct IMAP *imap = conn->data->req.protop;

  (void)connected;

  if(imap->transfer != FTPTRANSFER_BODY)
    /* no data to transfer */
    Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);

  return CURLE_OK;
}

Project: curl
File: imap.c

static CURLcode imap_state_append_resp(struct connectdata *conn, int imapcode,
                                       imapstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;

  (void)instate; /* No use for this yet */

  if(imapcode != '+') {
    result = CURLE_UPLOAD_FAILED;
  }
  else {
    /* Set the progress upload size */
    Curl_pgrsSetUploadSize(data, data->state.infilesize);

    /* IMAP upload */
    Curl_setup_transfer(conn, -1, -1, FALSE, NULL, FIRSTSOCKET, NULL);

    /* End of DO phase */
    state(conn, IMAP_STOP);
  }

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_regular_transfer(struct connectdata *conn,
                                      bool *dophase_done)
{
  CURLcode result = CURLE_OK;
  bool connected = FALSE;
  struct Curl_easy *data = conn->data;

  /* Make sure size is unknown at this point */
  data->req.size = -1;

  /* Set the progress data */
  Curl_pgrsSetUploadCounter(data, 0);
  Curl_pgrsSetDownloadCounter(data, 0);
  Curl_pgrsSetUploadSize(data, -1);
  Curl_pgrsSetDownloadSize(data, -1);

  /* Carry out the perform */
  result = imap_perform(conn, &connected, dophase_done);

  /* Perform post DO phase operations if necessary */
  if(!result && *dophase_done)
    result = imap_dophase_done(conn, connected);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_upgrade_tls(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;

  /* Start the SSL connection */
  result = Curl_ssl_connect_nonblocking(conn, FIRSTSOCKET, &imapc->ssldone);

  if(!result) {
    if(imapc->state != IMAP_UPGRADETLS)
      state(conn, IMAP_UPGRADETLS);

    if(imapc->ssldone) {
      imap_to_imaps(conn);
      result = imap_perform_capability(conn);
    }
  }

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_starttls(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;

  /* Send the STARTTLS command */
  result = imap_sendf(conn, "STARTTLS");

  if(!result)
    state(conn, IMAP_STARTTLS);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_state_servergreet_resp(struct connectdata *conn,
                                            int imapcode,
                                            imapstate instate)
{
  struct Curl_easy *data = conn->data;
  (void)instate; /* no use for this yet */

  if(imapcode == IMAP_RESP_PREAUTH) {
    /* PREAUTH */
    struct imap_conn *imapc = &conn->proto.imapc;
    imapc->preauth = TRUE;
    infof(data, "PREAUTH connection, already authenticated!\n");
  }
  else if(imapcode != IMAP_RESP_OK) {
    failf(data, "Got unexpected imap-server response");
    return CURLE_WEIRD_SERVER_REPLY;
  }

  return imap_perform_capability(conn);
}

Project: curl
File: imap.c

static CURLcode imap_perform_authentication(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;
  saslprogress progress;

  /* Check if already authenticated OR if there is enough data to authenticate
     with and end the connect phase if we don't */
  if(imapc->preauth ||
     !Curl_sasl_can_authenticate(&imapc->sasl, conn)) {
    state(conn, IMAP_STOP);
    return result;
  }

  /* Calculate the SASL login details */
  result = Curl_sasl_start(&imapc->sasl, conn, imapc->ir_supported, &progress);

  if(!result) {
    if(progress == SASL_INPROGRESS)
      state(conn, IMAP_AUTHENTICATE);
    else if(!imapc->login_disabled && (imapc->preftype & IMAP_TYPE_CLEARTEXT))
      /* Perform clear text authentication */
      result = imap_perform_login(conn);
    else {
      /* Other mechanisms not supported */
      infof(conn->data, "No known authentication mechanisms supported!\n");
      result = CURLE_LOGIN_DENIED;
    }
  }

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_do(struct connectdata *conn, bool *done)
{
  CURLcode result = CURLE_OK;

  *done = FALSE; /* default to false */

  /* Parse the URL path */
  result = imap_parse_url_path(conn);
  if(result)
    return result;

  /* Parse the custom request */
  result = imap_parse_custom_request(conn);
  if(result)
    return result;

  result = imap_regular_transfer(conn, done);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_sendf(struct connectdata *conn, const char *fmt, ...)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;
  char *taggedfmt;
  va_list ap;

  DEBUGASSERT(fmt);

  /* Calculate the next command ID wrapping at 3 digits */
  imapc->cmdid = (imapc->cmdid + 1) % 1000;

  /* Calculate the tag based on the connection ID and command ID */
  snprintf(imapc->resptag, sizeof(imapc->resptag), "%c%03d",
           'A' + curlx_sltosi(conn->connection_id % 26), imapc->cmdid);

  /* Prefix the format with the tag */
  taggedfmt = aprintf("%s %s", imapc->resptag, fmt);
  if(!taggedfmt)
    return CURLE_OUT_OF_MEMORY;

  /* Send the data with the tag */
  va_start(ap, fmt);
  result = Curl_pp_vsendf(&imapc->pp, taggedfmt, ap);
  va_end(ap);

  free(taggedfmt);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_capability(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct imap_conn *imapc = &conn->proto.imapc;

  imapc->sasl.authmechs = SASL_AUTH_NONE; /* No known auth. mechanisms yet */
  imapc->sasl.authused = SASL_AUTH_NONE;  /* Clear the auth. mechanism used */
  imapc->tls_supported = FALSE;           /* Clear the TLS capability */

  /* Send the CAPABILITY command */
  result = imap_sendf(conn, "CAPABILITY");

  if(!result)
    state(conn, IMAP_CAPABILITY);

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform(struct connectdata *conn, bool *connected,
                             bool *dophase_done)
{
  /* This is IMAP and no proxy */
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap = data->req.protop;
  struct imap_conn *imapc = &conn->proto.imapc;
  bool selected = FALSE;

  DEBUGF(infof(conn->data, "DO phase starts\n"));

  if(conn->data->set.opt_no_body) {
    /* Requested no body means no transfer */
    imap->transfer = FTPTRANSFER_INFO;
  }

  *dophase_done = FALSE; /* not done yet */

  /* Determine if the requested mailbox (with the same UIDVALIDITY if set)
     has already been selected on this connection */
  if(imap->mailbox && imapc->mailbox &&
     !strcmp(imap->mailbox, imapc->mailbox) &&
     (!imap->uidvalidity || !imapc->mailbox_uidvalidity ||
      !strcmp(imap->uidvalidity, imapc->mailbox_uidvalidity)))
    selected = TRUE;

  /* Start the first command in the DO phase */
  if(conn->data->set.upload || data->set.mimepost.kind != MIMEKIND_NONE)
    /* APPEND can be executed directly */
    result = imap_perform_append(conn);
  else if(imap->custom && (selected || !imap->mailbox))
    /* Custom command using the same mailbox or no mailbox */
    result = imap_perform_list(conn);
  else if(!imap->custom && selected && imap->uid)
    /* FETCH from the same mailbox */
    result = imap_perform_fetch(conn);
  else if(!imap->custom && selected && imap->query)
    /* SEARCH the current mailbox */
    result = imap_perform_search(conn);
  else if(imap->mailbox && !selected &&
         (imap->custom || imap->uid || imap->query))
    /* SELECT the mailbox */
    result = imap_perform_select(conn);
  else
    /* LIST */
    result = imap_perform_list(conn);

  if(result)
    return result;

  /* Run the state-machine */
  result = imap_multi_statemach(conn, dophase_done);

  *connected = conn->bits.tcpconnect[FIRSTSOCKET];

  if(*dophase_done)
    DEBUGF(infof(conn->data, "DO phase is complete\n"));

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_init(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct IMAP *imap;

  imap = data->req.protop = calloc(sizeof(struct IMAP), 1);
  if(!imap)
    result = CURLE_OUT_OF_MEMORY;

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_statemach_act(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  curl_socket_t sock = conn->sock[FIRSTSOCKET];
  int imapcode;
  struct imap_conn *imapc = &conn->proto.imapc;
  struct pingpong *pp = &imapc->pp;
  size_t nread = 0;

  /* Busy upgrading the connection; right now all I/O is SSL/TLS, not IMAP */
  if(imapc->state == IMAP_UPGRADETLS)
    return imap_perform_upgrade_tls(conn);

  /* Flush any data that needs to be sent */
  if(pp->sendleft)
    return Curl_pp_flushsend(pp);

  do {
    /* Read the response from the server */
    result = Curl_pp_readresp(sock, pp, &imapcode, &nread);
    if(result)
      return result;

    /* Was there an error parsing the response line? */
    if(imapcode == -1)
      return CURLE_WEIRD_SERVER_REPLY;

    if(!imapcode)
      break;

    /* We have now received a full IMAP server response */
    switch(imapc->state) {
    case IMAP_SERVERGREET:
      result = imap_state_servergreet_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_CAPABILITY:
      result = imap_state_capability_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_STARTTLS:
      result = imap_state_starttls_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_AUTHENTICATE:
      result = imap_state_auth_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_LOGIN:
      result = imap_state_login_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_LIST:
      result = imap_state_listsearch_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_SELECT:
      result = imap_state_select_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_FETCH:
      result = imap_state_fetch_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_FETCH_FINAL:
      result = imap_state_fetch_final_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_APPEND:
      result = imap_state_append_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_APPEND_FINAL:
      result = imap_state_append_final_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_SEARCH:
      result = imap_state_listsearch_resp(conn, imapcode, imapc->state);
      break;

    case IMAP_LOGOUT:
      /* fallthrough, just stop! */
    default:
      /* internal error */
      state(conn, IMAP_STOP);
      break;
    }
  } while(!result && imapc->state != IMAP_STOP && Curl_pp_moredata(pp));

  return result;
}

Project: curl
File: imap.c

static CURLcode imap_perform_logout(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;

  /* Send the LOGOUT command */
  result = imap_sendf(conn, "LOGOUT");

  if(!result)
    state(conn, IMAP_LOGOUT);

  return result;
}