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CURLOPT_SSL_VERIFYPEER(3)           libcurl          CURLOPT_SSL_VERIFYPEER(3)


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.

       When libcurl uses secure protocols it trusts responses and allows for
       example HSTS and Alt-Svc information to be stored and used
       subsequently. Disabling certificate verification can make libcurl trust
       and use such information from malicious servers.


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),

ibcurl 8.1.2                    April 26, 2023       CURLOPT_SSL_VERIFYPEER(3)

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