CURLOPT_SSL_VERIFYHOST(3) curl_easy_setopt options CURLOPT_SSL_VERIFYHOST(3)NAMECURLOPT_SSL_VERIFYHOST - verify the certificate's name against host
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_VERIFYHOST, long
verify);
DESCRIPTION
Pass a long as parameter specifying what to verify.
This option determines whether libcurl verifies that the server cert is
for the server it is known as.
When negotiating TLS and SSL connections, the server sends a certifi‐
cate indicating its identity.
When CURLOPT_SSL_VERIFYHOST(3) is 2, that certificate must indicate
that the server is the server to which you meant to connect, or the
connection fails. Simply put, it means it has to have the same name in
the certificate as is in the URL you operate against.
Curl considers the server the intended one when the Common Name field
or a Subject Alternate Name field in the certificate matches the host
name in the URL to which you told Curl to connect.
When the verify value is 1, curl_easy_setopt will return an error and
the option value will not be changed. It was previously (in 7.28.0 and
earlier) a debug option of some sorts, but it is no longer supported
due to frequently leading to programmer mistakes. Future versions will
stop returning an error for 1 and just treat 1 and 2 the same.
When the verify value is 0, the connection succeeds regardless of the
names in the certificate. Use that ability with caution!
The default value for this option is 2.
This option controls checking the server's certificate's claimed iden‐
tity. The server could be lying. To control lying, see CUR‐
LOPT_SSL_VERIFYPEER(3). If libcurl is built against NSS and CUR‐
LOPT_SSL_VERIFYPEER(3) is zero, CURLOPT_SSL_VERIFYHOST(3) is also set
to zero and cannot be overridden.
DEFAULT
2
PROTOCOLS
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
EXAMPLE
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
/* Set the default value: strict name check please */
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
curl_easy_perform(curl);
}
AVAILABILITY
If built TLS enabled.
RETURN VALUE
Returns CURLE_OK if TLS is supported, and CURLE_UNKNOWN_OPTION if not.
If 1 is set as argument, CURLE_BAD_FUNCTION_ARGUMENT is returned.
SEE ALSOCURLOPT_SSL_VERIFYPEER(3), CURLOPT_CAINFO(3),
libcurl 7.37.0 17 Jun 2014 CURLOPT_SSL_VERIFYHOST(3)
