NAME

       CURLOPT_SSL_VERIFYPEER - verify the peer's SSL certificate

SYNOPSIS

       #include <curl/curl.h>

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

DESCRIPTION

       Pass a long as parameter to enable or disable.

       This  option  determines  whether  curl verifies the authenticity of the peer's certificate. A value of 1
       means curl verifies; 0 (zero) means it does not.

       When negotiating a TLS or SSL connection, the server sends a certificate indicating its  identity.   Curl
       verifies  whether  the  certificate  is  authentic,  i.e.  that  you can trust that the server is who the
       certificate 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 determined at build time) and you can specify alternate certificates with the CURLOPT_CAINFO(3) option
       or the CURLOPT_CAPATH(3) option.

       When  CURLOPT_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_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 CURLOPT_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 communicating with the correct end-point.

       NOTE:  even  when  this  option  is  disabled, depending on the used TLS backend, curl may still load the
       certificate file specified in CURLOPT_CAINFO(3). curl default settings in some  distributions  might  use
       quite  a  large  file  as  a  default  setting  for  CURLOPT_CAINFO(3),  so loading the file can be quite
       expensive, especially when dealing with many connections. Thus, in some situations,  you  might  want  to
       disable  verification  fully  to  save  resources  by setting CURLOPT_CAINFO(3) to NULL - but please also
       consider the warning above!

DEFAULT

       By default, curl assumes a value of 1.

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 certificate check please */
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);

         curl_easy_perform(curl);
       }

AVAILABILITY

       If built TLS enabled.

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_SSL_VERIFYHOST(3),       CURLOPT_PROXY_SSL_VERIFYPEER(3),        CURLOPT_PROXY_SSL_VERIFYHOST(3),
       CURLOPT_CAINFO(3),

libcurl 7.81.0                                  November 26, 2021                      CURLOPT_SSL_VERIFYPEER(3)