Tribblix: manual page: CURLOPT

CURLOPT_CAINFO(3) Introduction to Library Functions CURLOPT_CAINFO(3)

NAME

CURLOPT_CAINFO - path to Certificate Authority (CA) bundle

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CAINFO, char *path);

DESCRIPTION

Pass a char pointer to a null-terminated string naming a file holding
one or more certificates to verify the peer with.

If CURLOPT_SSL_VERIFYPEER(3) is zero and you avoid verifying the
server's certificate, CURLOPT_CAINFO(3) 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.

(iOS and macOS) When curl uses Secure Transport this option is
supported. If the option is not set, then curl uses the certificates
in the system and user Keychain to verify the peer.

(Schannel) This option is supported for Schannel in Windows 7 or
later but we recommend not using it until Windows 8 since it works
better starting then. If the option is not set, then curl uses the
certificates in the Windows' store of root certificates (the default
for Schannel).

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.

The default value for this can be figured out with
CURLINFO_CAINFO(3).

DEFAULT

Built-in system specific. When curl is built with Secure Transport or
Schannel, this option is not set by default.

PROTOCOLS

This functionality affects all TLS based protocols: HTTPS, FTPS,
IMAPS, POP3S, SMTPS etc.

All TLS backends support this option.

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_CAINFO, "/etc/certs/cabundle.pem");
curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}

HISTORY

Schannel support added in libcurl 7.60.

AVAILABILITY

Added in curl 7.4.2

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).