NAME

       CURLOPT_SSL_OPTIONS - set SSL behavior options

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_OPTIONS, long bitmask);

DESCRIPTION

       Pass a long with a bitmask to tell libcurl about specific SSL behaviors. Available bits:

       CURLSSLOPT_ALLOW_BEAST
              Tells  libcurl  to  not  attempt to use any workarounds for a security flaw in the SSL3 and TLS1.0
              protocols.  If this option isn't used or this bit is set to 0, the SSL layer libcurl uses may  use
              a  work-around  for  this flaw although it might cause interoperability problems with some (older)
              SSL implementations. WARNING: avoiding this work-around lessens the security, and by setting  this
              option  to  1  you  ask  for  exactly  that.  This option is only supported for DarwinSSL, NSS and
              OpenSSL.

       CURLSSLOPT_NO_REVOKE
              Tells libcurl to disable certificate revocation checks for those SSL backends where such  behavior
              is  present.  This option is only supported for Schannel (the native Windows SSL library), with an
              exception in the case of Windows' Untrusted Publishers blacklist which it seems can't be bypassed.
              (Added in 7.44.0)

       CURLSSLOPT_NO_PARTIALCHAIN
              Tells libcurl to not accept "partial" certificate chains, which it otherwise does by default. This
              option is only supported for OpenSSL and will fail the certificate verification if the chain  ends
              with an intermediate certificate and not with a root cert. (Added in 7.68.0)

DEFAULT

       0

PROTOCOLS

       All TLS-based protocols

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
         /* weaken TLS only for use with silly servers */
         curl_easy_setopt(curl, CURLOPT_SSL_OPTIONS, CURLSSLOPT_ALLOW_BEAST |
                          CURLSSLOPT_NO_REVOKE);
         ret = curl_easy_perform(curl);
         curl_easy_cleanup(curl);
       }

AVAILABILITY

       Added in 7.25.0

RETURN VALUE

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

SEE ALSO

       CURLOPT_SSLVERSION(3), CURLOPT_SSL_CIPHER_LIST(3),

libcurl 7.68.0                                  December 02, 2019                         CURLOPT_SSL_OPTIONS(3)