mirror of
https://github.com/moparisthebest/curl
synced 2024-12-23 08:38:49 -05:00
142 lines
5.2 KiB
Groff
142 lines
5.2 KiB
Groff
.\" **************************************************************************
|
|
.\" * _ _ ____ _
|
|
.\" * Project ___| | | | _ \| |
|
|
.\" * / __| | | | |_) | |
|
|
.\" * | (__| |_| | _ <| |___
|
|
.\" * \___|\___/|_| \_\_____|
|
|
.\" *
|
|
.\" * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
|
|
.\" *
|
|
.\" * This software is licensed as described in the file COPYING, which
|
|
.\" * you should have received as part of this distribution. The terms
|
|
.\" * are also available at https://curl.haxx.se/docs/copyright.html.
|
|
.\" *
|
|
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
|
.\" * copies of the Software, and permit persons to whom the Software is
|
|
.\" * furnished to do so, under the terms of the COPYING file.
|
|
.\" *
|
|
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
.\" * KIND, either express or implied.
|
|
.\" *
|
|
.\" **************************************************************************
|
|
.\"
|
|
.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.
|
|
.SH DEFAULT
|
|
NULL
|
|
.SH PROTOCOLS
|
|
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
|
|
.SH EXAMPLE
|
|
.nf
|
|
/* 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 = /* 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";
|
|
/* 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;
|
|
|
|
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 nescessary
|
|
* "modifications" to the SSL CONTEXT just before link init
|
|
*/
|
|
rv=curl_easy_setopt(ch, CURLOPT_SSL_CTX_FUNCTION, *sslctx_function);
|
|
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;
|
|
}
|
|
.fi
|
|
.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), "
|