---
name: "CURLOPT_SSH_PUBLIC_KEYFILE"
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_SSH_PUBLIC_KEYFILE"
---

# CURLOPT\_SSH\_PUBLIC\_KEYFILE(3)

public key file for SSH auth

## NAME

CURLOPT\_SSH\_PUBLIC\_KEYFILE - public key file for SSH auth

## SYNOPSIS

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

## DESCRIPTION

Pass a char pointer pointing to a *filename* for your public key. If not used, libcurl defaults to **$HOME/.ssh/id\_dsa.pub** if the HOME environment variable is set, and just "id\_dsa.pub" in the current directory if HOME is not set.

If NULL (or an empty string) is passed to this option, libcurl passes no public key to the SSH library, which then rather derives it from the private key. If the SSH library cannot derive the public key from the private one and no public one is provided, the transfer fails.

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

## DEFAULT

NULL

## PROTOCOLS

SFTP and SCP

## EXAMPLE

```
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/file");
    curl_easy_setopt(curl, CURLOPT_SSH_PUBLIC_KEYFILE,
                     "/home/clarkkent/.ssh/id_rsa.pub");
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

The "" trick was added in 7.26.0

## 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\_SSH\_AUTH\_TYPES**(3)](/CURLOPT_SSH_AUTH_TYPES/3.md), [**CURLOPT\_SSH\_PRIVATE\_KEYFILE**(3)](/CURLOPT_SSH_PRIVATE_KEYFILE/3.md)