CURLOPT_PROXY_SSLCERTTYPE(3) Library Functions Manual
NAME
CURLOPT_PROXY_SSLCERTTYPE - type of the proxy client SSL certificate
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLCERTTYPE, char *type);
DESCRIPTION
Pass a pointer to a null-terminated string as parameter. The string
should be the format of your client certificate used when connecting to
an HTTPS proxy.
Supported formats are "PEM" and "DER", except with Schannel. OpenSSL
and Schannel support "P12" for PKCS#12-encoded files.
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
"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, 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/");
curl_easy_setopt(curl, CURLOPT_PROXY, "https://proxy.example");
curl_easy_setopt(curl, CURLOPT_PROXY_SSLCERT, "client.pem");
curl_easy_setopt(curl, CURLOPT_PROXY_SSLCERTTYPE, "PEM");
curl_easy_setopt(curl, CURLOPT_PROXY_SSLKEY, "key.pem");
curl_easy_setopt(curl, CURLOPT_PROXY_KEYPASSWD, "s3cret");
result = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}
AVAILABILITY
Added in curl 7.52.0
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_PROXY_SSLCERT(3), CURLOPT_PROXY_SSLKEY(3),
CURLOPT_SSLCERTTYPE(3)
libcurl 2026-03-23 CURLOPT_PROXY_SSLCERTTYPE(3)
curl 8.19.0 - Generated Mon Mar 30 07:36:10 CDT 2026