CURLOPT_USE_SSL

Section: curl_easy_setopt options (3)
Updated: November 04, 2020
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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: Don't attempt to use SSL.
CURLUSESSL_TRY: Try using SSL, proceed as normal otherwise.
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

FTP, SMTP, POP3, IMAP

EXAMPLE

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, CURLUSESSL_ALL);

  /* Perform the request */
  curl_easy_perform(curl);
}

AVAILABILITY

Added in 7.11.0. This option was known as CURLOPT_FTP_SSL up to 7.16.4, and the constants were known as CURLFTPSSL_*

RETURN VALUE

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