1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: CURLOPT_USE_SSL 5Section: 3 6Source: libcurl 7See-also: 8 - CURLOPT_PROXY_SSLVERSION (3) 9 - CURLOPT_SSLVERSION (3) 10 - CURLOPT_SSL_OPTIONS (3) 11Protocol: 12 - FTP 13 - SMTP 14 - POP3 15 - IMAP 16Added-in: 7.17.0 17--- 18 19# NAME 20 21CURLOPT_USE_SSL - request using SSL / TLS for the transfer 22 23# SYNOPSIS 24 25~~~c 26#include <curl/curl.h> 27 28CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USE_SSL, long level); 29~~~ 30 31# DESCRIPTION 32 33Pass a long using one of the values from below, to make libcurl use your 34desired *level* of SSL for the transfer. 35 36These are all protocols that start out plain text and get "upgraded" to SSL 37using the STARTTLS command. 38 39This is for enabling SSL/TLS when you use FTP, SMTP, POP3, IMAP etc. 40 41## CURLUSESSL_NONE 42 43do not attempt to use SSL. 44 45## CURLUSESSL_TRY 46 47Try using SSL, proceed as normal otherwise. Note that server may close the 48connection if the negotiation does not succeed. 49 50## CURLUSESSL_CONTROL 51 52Require SSL for the control connection or fail with *CURLE_USE_SSL_FAILED*. 53 54## CURLUSESSL_ALL 55 56Require SSL for all communication or fail with *CURLE_USE_SSL_FAILED*. 57 58# DEFAULT 59 60CURLUSESSL_NONE 61 62# %PROTOCOLS% 63 64# EXAMPLE 65 66~~~c 67int main(void) 68{ 69 CURL *curl = curl_easy_init(); 70 if(curl) { 71 curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/dir/file.ext"); 72 73 /* require use of SSL for this, or fail */ 74 curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL); 75 76 /* Perform the request */ 77 curl_easy_perform(curl); 78 } 79} 80~~~ 81 82# HISTORY 83 84This option was known as CURLOPT_FTP_SSL up to 7.16.4, and the constants were 85known as CURLFTPSSL_* Handled by LDAP since 7.81.0. Fully supported by the 86OpenLDAP backend only. 87 88# %AVAILABILITY% 89 90# RETURN VALUE 91 92Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. 93
