CURLOPT_KEYPASSWD(3) Introduction to Library Functions CURLOPT_KEYPASSWD(3)
CURLOPT_KEYPASSWD - passphrase to private key
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_KEYPASSWD, char *pwd);
Pass a pointer to a null-terminated string as parameter. It is used
as the password required to use the CURLOPT_SSLKEY(3) or
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.
NULL
This functionality affects all TLS based protocols: HTTPS, FTPS,
IMAPS, POP3S, SMTPS etc.
This option works only with the following TLS backends: OpenSSL,
Schannel, mbedTLS and wolfSSL
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);
}
}
This option was known as CURLOPT_SSLKEYPASSWD up to 7.16.4 and
CURLOPT_SSLCERTPASSWD up to 7.9.2.
Added in curl 7.17.0
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).
CURLOPT_SSH_PRIVATE_KEYFILE(3), CURLOPT_SSLKEY(3)
libcurl 2026-01-08 CURLOPT_KEYPASSWD(3)
NAME
CURLOPT_KEYPASSWD - passphrase to private key
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_KEYPASSWD, char *pwd);
DESCRIPTION
Pass a pointer to a null-terminated string as parameter. It is used
as the password required to use the CURLOPT_SSLKEY(3) or
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
NULL
PROTOCOLS
This functionality affects 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
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
This option was known as CURLOPT_SSLKEYPASSWD up to 7.16.4 and
CURLOPT_SSLCERTPASSWD up to 7.9.2.
AVAILABILITY
Added in curl 7.17.0
RETURN VALUE
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).
SEE ALSO
CURLOPT_SSH_PRIVATE_KEYFILE(3), CURLOPT_SSLKEY(3)
libcurl 2026-01-08 CURLOPT_KEYPASSWD(3)