---
name: "CURLOPT_TLSAUTH_TYPE"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_TLSAUTH_TYPE"
---

# CURLOPT\_TLSAUTH\_TYPE(3)

TLS authentication methods

## NAME

CURLOPT\_TLSAUTH\_TYPE - TLS authentication methods

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TLSAUTH_TYPE, char *type);
```

## DESCRIPTION

Pass a pointer to a null-terminated string as parameter. The string should be the method of the TLS authentication. Supported method is "SRP".

- SRP

  TLS-SRP authentication. Secure Remote Password authentication for TLS is defined in RFC 5054 and provides mutual authentication if both sides have a shared secret. To use TLS-SRP, you must also set the *[CURLOPT\_TLSAUTH\_USERNAME(3)](/CURLOPT_TLSAUTH_USERNAME/3.md)* and *[CURLOPT\_TLSAUTH\_PASSWORD(3)](/CURLOPT_TLSAUTH_PASSWORD/3.md)* options.

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

  TLS SRP does not work with TLS 1.3.

## DEFAULT

blank

## PROTOCOLS

All TLS-based protocols

## 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_TLSAUTH_TYPE, "SRP");
    curl_easy_setopt(curl, CURLOPT_TLSAUTH_USERNAME, "user");
    curl_easy_setopt(curl, CURLOPT_TLSAUTH_PASSWORD, "secret");
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

You need to build libcurl with GnuTLS or OpenSSL with TLS-SRP support for this to work. Added in 7.21.4

## RETURN VALUE

Returns CURLE\_OK if the option is supported, and CURLE\_UNKNOWN\_OPTION if not.

## SEE ALSO

[**CURLOPT\_TLSAUTH\_PASSWORD**(3)](/CURLOPT_TLSAUTH_PASSWORD/3.md), [**CURLOPT\_TLSAUTH\_USERNAME**(3)](/CURLOPT_TLSAUTH_USERNAME/3.md)