---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Title: CURLOPT_PROXY_SSLCERT
Section: 3
Source: libcurl
See-also:
  - CURLOPT_PROXY_SSLCERTTYPE (3)
  - CURLOPT_PROXY_SSLKEY (3)
  - CURLOPT_SSLCERT (3)
Protocol:
  - TLS
TLS-backend:
  - OpenSSL
  - GnuTLS
  - mbedTLS
  - Schannel
  - wolfSSL
Added-in: 7.52.0
---

# NAME

CURLOPT_PROXY_SSLCERT - HTTPS proxy client certificate

# SYNOPSIS

~~~c
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLCERT, char *cert);
~~~

# DESCRIPTION

This option is for connecting to an HTTPS proxy, not an HTTPS server.

Pass a pointer to a null-terminated string as parameter. The string should be
the filename of your client certificate used to connect to the HTTPS proxy.
The default format "PEM", and can be changed with
CURLOPT_PROXY_SSLCERTTYPE(3).

When using a client certificate, you most likely also need to provide a
private key with CURLOPT_PROXY_SSLKEY(3).

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%

# EXAMPLE

~~~c
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_SSLKEY, "key.pem");
    curl_easy_setopt(curl, CURLOPT_PROXY_KEYPASSWD, "s3cret");
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
~~~

# %AVAILABILITY%

# 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).