CURLOPT_DOH_SSL_VERIFYPEER - verify the DoH SSL certificate
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_SSL_VERIFYPEER, long verify);
curl_easy_setopt options CURLOPT_DOH_SSL_VERIFYPEER(3)
NAME
CURLOPT_DOH_SSL_VERIFYPEER - verify the DoH SSL certificate
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_SSL_VERIFYPEER,
long verify);
DESCRIPTION
Pass a long as parameter set to 1L to enable or 0L to disable.
This option tells curl to verify the authenticity of the DoH (DNS-over-
HTTPS) server's certificate. A value of 1 means curl verifies; 0 (zero)
means it does not.
This option is the DoH equivalent of CURLOPT_SSL_VERIFYPEER(3) and only
affects requests to the DoH server.
When negotiating a TLS or SSL connection, the server sends a certifi-
cate indicating its identity. Curl verifies whether the certificate is
authentic, i.e. that you can trust that the server is who the certifi-
cate says it is. This trust is based on a chain of digital signatures,
rooted in certification authority (CA) certificates you supply. curl
uses a default bundle of CA certificates (the path for that is deter-
mined at build time) and you can specify alternate certificates with
the CURLOPT_CAINFO(3) option or the CURLOPT_CAPATH(3) option.
When CURLOPT_DOH_SSL_VERIFYPEER(3) is enabled, and the verification
fails to prove that the certificate is authentic, the connection fails.
When the option is zero, the peer certificate verification succeeds
regardless.
Authenticating the certificate is not enough to be sure about the
server. You typically also want to ensure that the server is the server
you mean to be talking to. Use CURLOPT_DOH_SSL_VERIFYHOST(3) for that.
The check that the host name in the certificate is valid for the host
name you are connecting to is done independently of the CUR-
LOPT_DOH_SSL_VERIFYPEER(3) option.
WARNING: disabling verification of the certificate allows bad guys to
man-in-the-middle the communication without you knowing it. Disabling
verification makes the communication insecure. Just having encryption
on a transfer is not enough as you cannot be sure that you are communi-
cating with the correct end-point.
DEFAULT
1
PROTOCOLS
DoH
EXAMPLE
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
curl_easy_setopt(curl, CURLOPT_DOH_URL, "https://cloudflare-dns.com/dns-query");
/* Disable certificate verification of the DoH server */
curl_easy_setopt(curl, CURLOPT_DOH_SSL_VERIFYPEER, 0L);
curl_easy_perform(curl);
}
AVAILABILITY
Added in 7.76.0
If built TLS enabled.
RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION
if not.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | web/curl |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
CURLOPT_DOH_SSL_VERIFYHOST(3), CURLOPT_SSL_VERIFYHOST(3), CUR-
LOPT_SSL_VERIFYPEER(3), CURLOPT_PROXY_SSL_VERIFYPEER(3), CUR-
LOPT_PROXY_SSL_VERIFYHOST(3), CURLOPT_CAINFO(3), CURLOPT_CAPATH(3),
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from https://curl.se/down-
load/curl-7.83.1.tar.bz2.
Further information about this software can be found on the open source
community website at http://curl.haxx.se/.
libcurl 7.83.1 November 26, 2021
CURLOPT_DOH_SSL_VERIFYPEER(3)