CURLOPT_USE_SSL(3)

NAME
CURLOPT_USE_SSL - request using SSL / TLS for the transfer

SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_USE_SSL, long level);

DESCRIPTION
Pass a long using one of the values from below, to make libcurl use your desired level 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.

CURLUSESSL_NONE
    do not attempt to use SSL.

CURLUSESSL_TRY
    Try using SSL, proceed as normal otherwise. Note that server may close the connection if the negotiation does not succeed.

CURLUSESSL_CONTROL
    Require SSL for the control connection or fail with CURLE_USE_SSL_FAILED.

CURLUSESSL_ALL
    Require SSL for all communication or fail with CURLE_USE_SSL_FAILED.

DEFAULT
CURLUSESSL_NONE

PROTOCOLS
This functionality affects ftp, imap, pop3 and smtp

EXAMPLE
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);
  }
}

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.

AVAILABILITY
Added in curl 7.17.0

RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO
CURLOPT_PROXY_SSLVERSION(3), CURLOPT_SSLVERSION(3), CURLOPT_SSL_OPTIONS(3)