On Tue, Jan 27, 2015 at 10:09:38PM +0300, Serj wrote:
> 27.01.2015, 20:23, "Viktor Dukhovni" <openssl-us...@dukhovni.org>:
> > I would set SSL verification parameters is to obtain the parameter
> > handle via SSL_get0_param() or where appropriate SSL_CTX_get0_param(),
> > and use the various X509_VERIFY_PARAM_mumble() functions to tweak
> > the parameter object in place.
>
> Why are not there any X509_VERIFY_PARAM_mumble() functions in your code?
> So your code is not complete?
It is complete enough. The word "mumble" is not meant to be taken
literally. The phrase:
"various X509_VERIFY_PARAM_mumble() functions"
means any of:
X509_VERIFY_PARAM_set_hostflags()
X509_VERIFY_PARAM_set1_host()
...
> > As I mentioned, this function should be documented, but is not yet.
> > The documentation for these functions is not yet written. ?The way
> > Yes, these need (more) documentation.
>
> That's why maybe it is better to use X509_check_host() in "post conection
> checks" now?
No, it is better to use the parameter functions, and also to document
the missing SSL_get0_param().
> NOTES
> Applications are encouraged to use X509_VERIFY_PARAM_set1_host()
> rather than explicitly calling X509_check_host(3). Host name checks
> are out of scope with the DANE-EE(3) certificate usage, and the
> internal checks will be suppressed as appropriate when DANE support
> is added to OpenSSL.
> ----------------------------------------------------------------------------------
> and no any documentation on how to set properly params for SSL or CTX!
Example code should likely be added to that document.
> Maybe this code is right, while there is no full documentation yet:
>
> char servername[]="www.openssl.org\x0";
> X509_VERIFY_PARAM *param;
> param = X509_VERIFY_PARAM_new();
>
> //enable automatic hostname checks
> X509_VERIFY_PARAM_set_hostflags(param,
> X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS);
> X509_VERIFY_PARAM_set1_host(param, servername,0);
> SSL_CTX_set1_param(ctx, param); //is right if combined by a bitwise 'OR'
> operation
>
> //free param
> X509_VERIFY_PARAM_free(param);
No, use the code example I provided. The above sets the hostname
in the global context, where it does not belong. My original
message is below:
On Sun, Jan 25, 2015 at 05:57:06PM +0000, Viktor Dukhovni wrote:
> On Sun, Jan 25, 2015 at 07:43:14PM +0300, Serj wrote:
>
> > What is the best way to make hostname validation?
> >
> > 1. http://wiki.openssl.org/index.php/Hostname_validation
> > 2. X509_check_host that was added in OpenSSL 1.1.0.
>
> The X509_check_host() interface is also available in OpenSSL 1.0.2
> released a few days ago
>
> https://www.openssl.org/docs/crypto/X509_check_host.html
>
> (the documentation should be updated to note the earlier availability).
>
> Starting with 1.0.2, you can also ask OpenSSL to automatically
> perform hostname checks during the SSL handshake on the application's
> behalf:
>
> https://www.openssl.org/docs/crypto/X509_VERIFY_PARAM_set_hostflags.html
> https://www.openssl.org/docs/crypto/X509_VERIFY_PARAM_set1_host.html
> https://www.openssl.org/docs/crypto/X509_VERIFY_PARAM_add1_host.html
> https://www.openssl.org/docs/ssl/SSL_set_verify.html
>
> Sadly, we're still lacking documentation of SSL_get0_param() which
> is needed for a complete SSL hostname check recipe:
>
> const char *servername;
> SSL *ssl;
> X509_VERIFY_PARAM *param;
>
> servername = "www.example.com";
> ssl = SSL_new(...);
> param = SSL_get0_param(ssl);
>
> /* Enable automatic hostname checks */
> X509_VERIFY_PARAM_set_hostflags(param,
> X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS);
> X509_VERIFY_PARAM_set1_host(param, servername, 0);
>
> /* Configure a non-zero callback if desired */
> SSL_set_verify(ssl, SSL_VERIFY_PEER, 0);
>
> /*
> * Establish SSL connection, hostname should be checked
> * automatically test with a hostname that should not match,
> * the connection will fail (unless you specify a callback
> * that returns despite the verification failure. In that
> * case SSL_get_verify_status() can expose the problem after
> * connection completion.
> */
> ...
>
> > I don't know does the first one support wildcards or no! Seems
> > to be: how does Curl_cert_hostcheck work - is the answer, but I
> > don't know how it works.
>
> Wildcard support is configured via the flags documented for X509_check_host(),
> the two most frequently useful are:
>
> X509_CHECK_FLAG_NO_WILDCARDS
> X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
--
Viktor.
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