1---
2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLOPT_FTP_SSL_CCC
5Section: 3
6Source: libcurl
7Protocol:
8  - FTP
9See-also:
10  - CURLOPT_FTPSSLAUTH (3)
11  - CURLOPT_PROTOCOLS_STR (3)
12  - CURLOPT_USE_SSL (3)
13---
14
15# NAME
16
17CURLOPT_FTP_SSL_CCC - switch off SSL again with FTP after auth
18
19# SYNOPSIS
20
21~~~c
22#include <curl/curl.h>
23
24CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SSL_CCC,
25                          long how);
26~~~
27
28# DESCRIPTION
29
30If enabled, this option makes libcurl use CCC (Clear Command Channel). It
31shuts down the SSL/TLS layer after authenticating. The rest of the control
32channel communication remains unencrypted. This allows NAT routers to follow
33the FTP transaction. Pass a long using one of the values below
34
35## CURLFTPSSL_CCC_NONE
36
37do not attempt to use CCC.
38
39## CURLFTPSSL_CCC_PASSIVE
40
41Do not initiate the shutdown, but wait for the server to do it. Do not send a
42reply.
43
44## CURLFTPSSL_CCC_ACTIVE
45
46Initiate the shutdown and wait for a reply.
47
48# DEFAULT
49
50CURLFTPSSL_CCC_NONE
51
52# EXAMPLE
53
54~~~c
55int main(void)
56{
57  CURL *curl = curl_easy_init();
58  if(curl) {
59    CURLcode res;
60    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/file.txt");
61    curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_CONTROL);
62    /* go back to clear-text FTP after authenticating */
63    curl_easy_setopt(curl, CURLOPT_FTP_SSL_CCC, (long)CURLFTPSSL_CCC_ACTIVE);
64    res = curl_easy_perform(curl);
65    curl_easy_cleanup(curl);
66  }
67}
68~~~
69
70# AVAILABILITY
71
72Added in 7.16.1
73
74# RETURN VALUE
75
76Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
77