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)
13Added-in: 7.16.1
14---
15
16# NAME
17
18CURLOPT_FTP_SSL_CCC - switch off SSL again with FTP after auth
19
20# SYNOPSIS
21
22~~~c
23#include <curl/curl.h>
24
25CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SSL_CCC,
26                          long how);
27~~~
28
29# DESCRIPTION
30
31If enabled, this option makes libcurl use CCC (Clear Command Channel). It
32shuts down the SSL/TLS layer after authenticating. The rest of the control
33channel communication remains unencrypted. This allows NAT routers to follow
34the FTP transaction. Pass a long using one of the values below
35
36## CURLFTPSSL_CCC_NONE
37
38do not attempt to use CCC.
39
40## CURLFTPSSL_CCC_PASSIVE
41
42Do not initiate the shutdown, but wait for the server to do it. Do not send a
43reply.
44
45## CURLFTPSSL_CCC_ACTIVE
46
47Initiate the shutdown and wait for a reply.
48
49# DEFAULT
50
51CURLFTPSSL_CCC_NONE
52
53# %PROTOCOLS%
54
55# EXAMPLE
56
57~~~c
58int main(void)
59{
60  CURL *curl = curl_easy_init();
61  if(curl) {
62    CURLcode res;
63    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/file.txt");
64    curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_CONTROL);
65    /* go back to clear-text FTP after authenticating */
66    curl_easy_setopt(curl, CURLOPT_FTP_SSL_CCC, (long)CURLFTPSSL_CCC_ACTIVE);
67    res = curl_easy_perform(curl);
68    curl_easy_cleanup(curl);
69  }
70}
71~~~
72
73# %AVAILABILITY%
74
75# RETURN VALUE
76
77Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
78