CURLOPT\_KEYPASSWD(3) Library Functions Manual CURLOPT\_KEYPASSWD(3)

# [NAME](#NAME)

CURLOPT\_KEYPASSWD - passphrase to private key

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#DESCRIPTION)

Pass a pointer to a null-terminated string as parameter. It is used as the password required to use the [*CURLOPT\_SSLKEY(3)*](/man/os/curl/CURLOPT_SSLKEY.3) or [*CURLOPT\_SSH\_PRIVATE\_KEYFILE(3)*](/man/os/curl/CURLOPT_SSH_PRIVATE_KEYFILE.3) private key. You never need a passphrase to load a certificate but you need one to load your private key.

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

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

# [DEFAULT](#DEFAULT)

NULL

# [PROTOCOLS](#PROTOCOLS)

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

This option works only with the following TLS backends: OpenSSL, Schannel, mbedTLS and wolfSSL

# [EXAMPLE](#EXAMPLE)

```
int main(void)
{


  CURL *curl = curl_easy_init();


  if(curl) {


    CURLcode result;


    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");


    curl_easy_setopt(curl, CURLOPT_SSLCERT, "client.pem");


    curl_easy_setopt(curl, CURLOPT_SSLKEY, "key.pem");


    curl_easy_setopt(curl, CURLOPT_KEYPASSWD, "superman");


    result = curl_easy_perform(curl);


    curl_easy_cleanup(curl);


  }
}
```

# [HISTORY](#HISTORY)

This option was known as CURLOPT\_SSLKEYPASSWD up to 7.16.4 and CURLOPT\_SSLCERTPASSWD up to 7.9.2.

# [AVAILABILITY](#AVAILABILITY)

Added in curl 7.17.0

# [RETURN VALUE](#RETURN_VALUE)

[*curl\_easy\_setopt(3)*](/man/os/curl/curl_easy_setopt.3) returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see [*libcurl-errors(3)*](/man/os/curl/libcurl-errors.3).

# [SEE ALSO](#SEE_ALSO)

[**CURLOPT\_SSH\_PRIVATE\_KEYFILE**(3)](/man/os/curl/CURLOPT_SSH_PRIVATE_KEYFILE.3), [**CURLOPT\_SSLKEY**(3)](/man/os/curl/CURLOPT_SSLKEY.3)

2026-10-14 libcurl

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Document: CURLOPT_KEYPASSWD(3) from curl 8.23.0-r0 (Chainguard OS)
Source: https://github.com/curl/curl.git