NAME

       CURLOPT_SSLENGINE - Set SSL engine or provider

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSLENGINE, char *id);

DESCRIPTION

       Pass  a  pointer to a null-terminated string as parameter. It is used as the identifier for the engine or
       provider you want to use for your private key. OpenSSL 1 had engines, OpenSSL 3 has providers.

       The application does not have to keep the string around after setting this option.

       When asking libcurl to use a provider, the application can also optionally provide a property, a  set  of
       name value pairs. Such a property can be specified separated from the name with a colon (:).

       Using  this option multiple times makes the last set string override the previous ones. Set it to NULL to
       disable its use again.

DEFAULT

       NULL

PROTOCOLS

       This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

       This option works only with the following TLS backends: OpenSSL

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode res;
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
           curl_easy_setopt(curl, CURLOPT_SSLENGINE, "dynamic");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY

       Added in curl 7.9.3

RETURN VALUE

       CURLE_OK - Engine found.

       CURLE_SSL_ENGINE_NOTFOUND - Engine not found, or OpenSSL was not built with engine support.

       CURLE_SSL_ENGINE_INITFAILED - Engine found but initialization failed.

       CURLE_NOT_BUILT_IN - Option not built in, OpenSSL is not the SSL backend.

       CURLE_UNKNOWN_OPTION - Option not recognized.

       CURLE_OUT_OF_MEMORY - Insufficient heap space.

SEE ALSO

       CURLINFO_SSL_ENGINES(3), CURLOPT_SSLENGINE_DEFAULT(3), CURLOPT_SSLKEY(3)

libcurl                                            2025-06-16                               CURLOPT_SSLENGINE(3)