curl/docs/libcurl/opts/CURLOPT_PROXY_CAINFO.3

.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  Project                     ___| | | |  _ \| |
.\" *                             / __| | | | |_) | |
.\" *                            | (__| |_| |  _ <| |___
.\" *                             \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
.\" *
.\" * This software is licensed as described in the file COPYING, which
.\" * you should have received as part of this distribution. The terms
.\" * are also available at https://curl.se/docs/copyright.html.
.\" *
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
.\" *
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
.\" * KIND, either express or implied.
.\" *
.\" * SPDX-License-Identifier: curl
.\" *
.\" **************************************************************************
.\"
.TH CURLOPT_PROXY_CAINFO 3 "16 Nov 2016" libcurl libcurl
.SH NAME
CURLOPT_PROXY_CAINFO \- path to proxy Certificate Authority (CA) bundle
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_CAINFO, char *path);
.fi
.SH DESCRIPTION
This option is for connecting to an HTTPS proxy, not an HTTPS server.

Pass a char * to a null-terminated string naming a file holding one or more
certificates to verify the HTTPS proxy with.

If \fICURLOPT_PROXY_SSL_VERIFYPEER(3)\fP is zero and you avoid verifying the
server's certificate, \fICURLOPT_PROXY_CAINFO(3)\fP need not even indicate an
accessible file.

This option is by default set to the system path where libcurl's CA
certificate bundle is assumed to be stored, as established at build time.

If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module
(libnsspem.so) needs to be available for this option to work properly.

(iOS and macOS only) If curl is built against Secure Transport, then this
option is supported for backward compatibility with other SSL engines, but it
should not be set. If the option is not set, then curl will use the
certificates in the system and user Keychain to verify the peer, which is the
preferred method of verifying the peer's certificate chain.

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

The default value for this can be figured out with \fICURLINFO_CAINFO(3)\fP.
.SH DEFAULT
Built-in system specific
.SH PROTOCOLS
Used with HTTPS proxy
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
  /* using an HTTPS proxy */
  curl_easy_setopt(curl, CURLOPT_PROXY, "https://localhost:443");
  curl_easy_setopt(curl, CURLOPT_PROXY_CAINFO, "/etc/certs/cabundle.pem");
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}
.fi
.SH AVAILABILITY
Added in 7.52.0

For TLS backends that do not support certificate files, the
\fICURLOPT_PROXY_CAINFO(3)\fP option is ignored. Refer to
https://curl.se/docs/ssl-compared.html
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or
CURLE_OUT_OF_MEMORY if there was insufficient heap space.
.SH "SEE ALSO"
.BR CURLOPT_PROXY_CAINFO_BLOB "(3), " CURLOPT_PROXY_CAPATH "(3), "
.BR CURLOPT_PROXY_SSL_VERIFYPEER "(3), " CURLOPT_PROXY_SSL_VERIFYHOST "(3), "
.BR CURLOPT_CAINFO "(3), " CURLOPT_CAINFO_BLOB "(3), "
.BR CURLOPT_CAPATH "(3), "
.BR CURLOPT_SSL_VERIFYPEER "(3), " CURLOPT_SSL_VERIFYHOST "(3), "