Go to main content

man pages section 3: Library Interfaces and Headers

Exit Print View

Updated: Thursday, June 13, 2019
 
 

CURLOPT_SSL_CTX_DATA (3)

Name

CURLOPT_SSL_CTX_DATA - custom pointer passed to ssl_ctx callback

Synopsis

#include <curl/curl.h>

CURLcode   curl_easy_setopt(CURL  *handle,  CURLOPT_SSL_CTX_DATA,  void
*pointer);

Description

CURLOPT_SSL_CTX_DATA(3)    curl_easy_setopt options    CURLOPT_SSL_CTX_DATA(3)



NAME
       CURLOPT_SSL_CTX_DATA - custom pointer passed to ssl_ctx callback

SYNOPSIS
       #include <curl/curl.h>

       CURLcode   curl_easy_setopt(CURL  *handle,  CURLOPT_SSL_CTX_DATA,  void
       *pointer);

DESCRIPTION
       Data pointer to pass to the ssl context callback set by the option CUR-
       LOPT_SSL_CTX_FUNCTION(3),  this  is  the  pointer  you'll  get as third
       parameter.

DEFAULT
       NULL

PROTOCOLS
       All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

EXAMPLE
       /* OpenSSL specific */

       #include <openssl/ssl.h>
       #include <curl/curl.h>
       #include <stdio.h>

       static CURLcode sslctx_function(CURL *curl, void *sslctx, void *parm)
       {
         X509_STORE *store;
         X509 *cert=NULL;
         BIO *bio;
         char *mypem = (char *)parm;
         /* get a BIO */
         bio=BIO_new_mem_buf(mypem, -1);
         /* use it to read the PEM formatted certificate from memory into an
          * X509 structure that SSL can use
          */
         PEM_read_bio_X509(bio, &cert, 0, NULL);
         if(cert == NULL)
           printf("PEM_read_bio_X509 failed...\n");

         /* get a pointer to the X509 certificate store (which may be empty) */
         store=SSL_CTX_get_cert_store((SSL_CTX *)sslctx);

         /* add our certificate to this store */
         if(X509_STORE_add_cert(store, cert)==0)
           printf("error adding certificate\n");

         /* decrease reference counts */
         X509_free(cert);
         BIO_free(bio);

         /* all set to go */
         return CURLE_OK;
       }

       int main(void)
       {
         CURL * ch;
         CURLcode rv;
         char *mypem = /* example CA cert PEM - shortened */
           "-----BEGIN CERTIFICATE-----\n"
           "MIIHPTCCBSWgAwIBAgIBADANBgkqhkiG9w0BAQQFADB5MRAwDgYDVQQKEwdSb290\n"
           "IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNB\n"
           "IENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRA\n"
           "Y2FjZXJ0Lm9yZzAeFw0wMzAzMzAxMjI5NDlaFw0zMzAzMjkxMjI5NDlaMHkxEDAO\n"
           "GCSNe9FINSkYQKyTYOGWhlC0elnYjyELn8+CkcY7v2vcB5G5l1YjqrZslMZIBjzk\n"
           "zk6q5PYvCdxTby78dOs6Y5nCpqyJvKeyRKANihDjbPIky/qbn3BHLt4Ui9SyIAmW\n"
           "omTxJBzcoTWcFbLUvFUufQb1nA5V9FrWk9p2rSVzTMVD\n"
           "-----END CERTIFICATE-----\n";

         rv=curl_global_init(CURL_GLOBAL_ALL);
         ch=curl_easy_init();
         rv=curl_easy_setopt(ch, CURLOPT_SSLCERTTYPE, "PEM");
         rv=curl_easy_setopt(ch, CURLOPT_SSL_VERIFYPEER, 1L);
         rv=curl_easy_setopt(ch, CURLOPT_URL, "https://www.example.com/");

         /* Retrieve page using cacerts' certificate -> will succeed
          * load the certificate by installing a function doing the necessary
          * "modifications" to the SSL CONTEXT just before link init
          */
         rv=curl_easy_setopt(ch, CURLOPT_SSL_CTX_FUNCTION, *sslctx_function);
         rv=curl_easy_setopt(ch, CURLOPT_SSL_CTX_DATA, mypem);
         rv=curl_easy_perform(ch);
         if(rv==CURLE_OK)
           printf("*** transfer succeeded ***\n");
         else
           printf("*** transfer failed ***\n");

         curl_easy_cleanup(ch);
         curl_global_cleanup();
         return rv;
       }

AVAILABILITY
       Added in 7.11.0 for OpenSSL. Added in 7.42.0 for wolfSSL/CyaSSL.  Other
       SSL backends not supported.

RETURN VALUE
       CURLE_OK if supported; or an error such as:

       CURLE_NOT_BUILT_IN - Not supported by the SSL backend

       CURLE_UNKNOWN_OPTION


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | web/curl         |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+
SEE ALSO
       CURLOPT_SSL_CTX_FUNCTION(3), CURLOPT_SSLVERSION(3),



NOTES
       This     software     was    built    from    source    available    at
       https://github.com/oracle/solaris-userland.   The  original   community
       source    was    downloaded    from    https://github.com/curl/curl/ar-
       chive/curl-7_64_0.zip

       Further information about this software can be found on the open source
       community website at http://curl.haxx.se/.



libcurl 7.37.0                    19 Jun 2014          CURLOPT_SSL_CTX_DATA(3)