CURLOPT_DOH_SSL_VERIFYHOST(3)                         Library Functions Manual

NAME
       CURLOPT_DOH_SSL_VERIFYHOST - verify the hostname in the DoH SSL
       certificate

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_SSL_VERIFYHOST,
                                 long verify);

DESCRIPTION
       Pass a long set to 2L as asking curl to verify the DoH (DNS-over-HTTPS)
       server's certificate name fields against the hostname.

       This option is the DoH equivalent of CURLOPT_SSL_VERIFYHOST(3) and only
       affects requests to the DoH server.

       When CURLOPT_DOH_SSL_VERIFYHOST(3) is 2, the SSL certificate provided
       by the DoH server must indicate that the server name is the same as the
       server name to which you meant to connect to, or the connection fails.

       Curl considers the DoH server the intended one when the Common Name
       field or a Subject Alternate Name field in the certificate matches the
       hostname in the DoH URL to which you told Curl to connect.

       When the verify value is set to 1L it is treated the same as 2L.
       However for consistency with the other VERIFYHOST options we suggest
       use 2 and not 1.

       When the verify value is set to 0L, the connection succeeds regardless
       of the names used in the certificate. Use that ability with caution!

       See also CURLOPT_DOH_SSL_VERIFYPEER(3) to verify the digital signature
       of the DoH server certificate.

DEFAULT
       2

PROTOCOLS
       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_DOH_URL,
                            "https://cloudflare-dns.com/dns-query");

           /* Disable host name verification of the DoH server */
           curl_easy_setopt(curl, CURLOPT_DOH_SSL_VERIFYHOST, 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.

SEE ALSO
       CURLOPT_DOH_SSL_VERIFYPEER(3), CURLOPT_PROXY_SSL_VERIFYHOST(3),
       CURLOPT_PROXY_SSL_VERIFYPEER(3), CURLOPT_SSL_VERIFYHOST(3),
       CURLOPT_SSL_VERIFYPEER(3)

libcurl                          April 26 2024   CURLOPT_DOH_SSL_VERIFYHOST(3)