Set tls authentication methods
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TLSAUTH_TYPE, long bitmask);
Pass a long as parameter, which is set to a bitmask, to tell libcurl which authentication method(s) you want it to use for TLS authentication.
All TLS-based protocols
You need to build libcurl with GnuTLS or OpenSSL with TLS-SRP support for this to work. Added in 7.21.4
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.