CURLOPT_SSLCERTTYPE(3) Library Functions Manual CURLOPT_SSLCERTTYPE(3)
NAME
CURLOPT_SSLCERTTYPE - type of client SSL certificate
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSLCERTTYPE, char *type);
DESCRIPTION
Pass a pointer to a null-terminated string as parameter. The string
should be the format of your certificate.
Supported formats are "PEM" and "DER", except with Secure Transport or
Schannel. OpenSSL (versions 0.9.3 and later), Secure Transport (on iOS 5
or later, or macOS 10.7 or later) and Schannel support "P12" for
PKCS#12-encoded files. GnuTLS supports P12 starting with curl 8.11.0.
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 restores back to internal default.
DEFAULT
"PEM"
PROTOCOLS
This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS,
POP3S, SMTPS etc.
This option works only with the following TLS backends: GnuTLS, OpenSSL,
Schannel, Secure Transport, mbedTLS and wolfSSL
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_SSLCERT, "client.pem");
curl_easy_setopt(curl, CURLOPT_SSLCERTTYPE, "PEM");
curl_easy_setopt(curl, CURLOPT_SSLKEY, "key.pem");
curl_easy_setopt(curl, CURLOPT_KEYPASSWD, "s3cret");
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}
AVAILABILITY
Added in curl 7.9.3
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_SSLCERT(3), CURLOPT_SSLKEY(3)
libcurl 2026-07-12 CURLOPT_SSLCERTTYPE(3)
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