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| .TH CURLOPT_SSL_CTX_FUNCTION 3 "19 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options" |
| .SH NAME |
| CURLOPT_SSL_CTX_FUNCTION \- SSL context callback for OpenSSL or wolfSSL/CyaSSL |
| .SH SYNOPSIS |
| .nf |
| #include <curl/curl.h> |
| |
| CURLcode ssl_ctx_callback(CURL *curl, void *ssl_ctx, void *userptr); |
| |
| CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_CTX_FUNCTION, |
| ssl_ctx_callback); |
| .SH DESCRIPTION |
| This option only works for libcurl powered by OpenSSL or wolfSSL/CyaSSL. If |
| libcurl was built against another SSL library this functionality is absent. |
| |
| Pass a pointer to your callback function, which should match the prototype |
| shown above. |
| |
| This callback function gets called by libcurl just before the initialization |
| of an SSL connection after having processed all other SSL related options to |
| give a last chance to an application to modify the behaviour of the SSL |
| initialization. The \fIssl_ctx\fP parameter is actually a pointer to the SSL |
| library's \fISSL_CTX\fP. If an error is returned from the callback no attempt |
| to establish a connection is made and the perform operation will return the |
| callback's error code. Set the \fIuserptr\fP argument with the |
| \fICURLOPT_SSL_CTX_DATA(3)\fP option. |
| |
| This function will get called on all new connections made to a server, during |
| the SSL negotiation. The SSL_CTX pointer will be a new one every time. |
| |
| To use this properly, a non-trivial amount of knowledge of your SSL library |
| is necessary. For example, you can use this function to call library-specific |
| callbacks to add additional validation code for certificates, and even to |
| change the actual URI of a HTTPS request (example used in the lib509 test |
| case). See also the example section for a replacement of the key, certificate |
| and trust file settings. |
| .SH DEFAULT |
| NULL |
| .SH PROTOCOLS |
| All TLS based protocols: HTTPS, FTPS, IMAPS, POP3, SMTPS etc. |
| .SH EXAMPLE |
| TODO |
| .SH AVAILABILITY |
| Added in 7.11.0 for OpenSSL. Added in 7.42.0 for wolfSSL/CyaSSL. Other SSL |
| backends not supported. |
| .SH RETURN VALUE |
| Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. |
| .SH "SEE ALSO" |
| .BR CURLOPT_SSL_CTX_DATA "(3), " CURLOPT_SSL_VERIFYPEER "(3), " |
