---
name: "CURLOPT_TLSAUTH_USERNAME"
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_USERNAME"
---

# CURLOPT\_TLSAUTH\_USERNAME(3)

user name to use for TLS authentication

## NAME

CURLOPT\_TLSAUTH\_USERNAME - user name to use for TLS authentication

## SYNOPSIS

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

## DESCRIPTION

Pass a char pointer as parameter, which should point to the null-terminated username to use for the TLS authentication method specified with the *[CURLOPT\_TLSAUTH\_TYPE(3)](/CURLOPT_TLSAUTH_TYPE/3.md)* option. Requires that the *[CURLOPT\_TLSAUTH\_PASSWORD(3)](/CURLOPT_TLSAUTH_PASSWORD/3.md)* option also be set.

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

This feature relies in TLS SRP which does not work with TLS 1.3.

## DEFAULT

NULL

## 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

Added in 7.21.4, with the OpenSSL and GnuTLS backends only

## RETURN VALUE

Returns CURLE\_OK if the option is supported, CURLE\_UNKNOWN\_OPTION if not, or CURLE\_OUT\_OF\_MEMORY if there was insufficient heap space.

## SEE ALSO

[**CURLOPT\_TLSAUTH\_PASSWORD**(3)](/CURLOPT_TLSAUTH_PASSWORD/3.md), [**CURLOPT\_TLSAUTH\_TYPE**(3)](/CURLOPT_TLSAUTH_TYPE/3.md)