repo/core/curl/files/CURLOPT_USE_SSL.3

.\" generated by cd2nroff 0.1 from CURLOPT_USE_SSL.md
.TH CURLOPT_USE_SSL 3 "2024-08-02" libcurl
.SH NAME
CURLOPT_USE_SSL \- request using SSL / TLS for the transfer
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USE_SSL, long level);
.fi
.SH DESCRIPTION
Pass a long using one of the values from below, to make libcurl use your
desired \fIlevel\fP of SSL for the transfer.

These are all protocols that start out plain text and get "upgraded" to SSL
using the STARTTLS command.

This is for enabling SSL/TLS when you use FTP, SMTP, POP3, IMAP etc.
.IP CURLUSESSL_NONE
do not attempt to use SSL.
.IP CURLUSESSL_TRY
Try using SSL, proceed as normal otherwise. Note that server may close the
connection if the negotiation does not succeed.
.IP CURLUSESSL_CONTROL
Require SSL for the control connection or fail with \fICURLE_USE_SSL_FAILED\fP.
.IP CURLUSESSL_ALL
Require SSL for all communication or fail with \fICURLE_USE_SSL_FAILED\fP.
.SH DEFAULT
CURLUSESSL_NONE
.SH PROTOCOLS
This functionality affects ftp, imap, pop3 and smtp
.SH EXAMPLE
.nf
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/dir/file.ext");

    /* require use of SSL for this, or fail */
    curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL);

    /* Perform the request */
    curl_easy_perform(curl);
  }
}
.fi
.SH HISTORY
This option was known as CURLOPT_FTP_SSL up to 7.16.4, and the constants were
known as CURLFTPSSL_* Handled by LDAP since 7.81.0. Fully supported by the
OpenLDAP backend only.
.SH AVAILABILITY
Added in curl 7.17.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH SEE ALSO
.BR CURLOPT_PROXY_SSLVERSION (3),
.BR CURLOPT_SSLVERSION (3),
.BR CURLOPT_SSL_OPTIONS (3)