--- c: Copyright (C) Daniel Stenberg, , et al. SPDX-License-Identifier: curl Title: CURLOPT_FTP_SSL_CCC Section: 3 Source: libcurl See-also: - CURLOPT_FTPSSLAUTH (3) - CURLOPT_PROTOCOLS_STR (3) - CURLOPT_USE_SSL (3) --- # NAME CURLOPT_FTP_SSL_CCC - switch off SSL again with FTP after auth # SYNOPSIS ~~~c #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SSL_CCC, long how); ~~~ # DESCRIPTION If enabled, this option makes libcurl use CCC (Clear Command Channel). It shuts down the SSL/TLS layer after authenticating. The rest of the control channel communication remains unencrypted. This allows NAT routers to follow the FTP transaction. Pass a long using one of the values below ## CURLFTPSSL_CCC_NONE do not attempt to use CCC. ## CURLFTPSSL_CCC_PASSIVE Do not initiate the shutdown, but wait for the server to do it. Do not send a reply. ## CURLFTPSSL_CCC_ACTIVE Initiate the shutdown and wait for a reply. # DEFAULT CURLFTPSSL_CCC_NONE # PROTOCOLS FTP # EXAMPLE ~~~c int main(void) { CURL *curl = curl_easy_init(); if(curl) { CURLcode res; curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/file.txt"); curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_CONTROL); /* go back to clear-text FTP after authenticating */ curl_easy_setopt(curl, CURLOPT_FTP_SSL_CCC, (long)CURLFTPSSL_CCC_ACTIVE); res = curl_easy_perform(curl); curl_easy_cleanup(curl); } } ~~~ # AVAILABILITY Added in 7.16.1 # RETURN VALUE Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.