NE_SSL_SET_VERIFY(3)						neon API reference					      NE_SSL_SET_VERIFY(3)

NAME

       ne_ssl_set_verify - register an SSL certificate verification callback

SYNOPSIS

       #include <ne_session.h>

       typedef int ne_ssl_verify_fn (void *userdata, int failures, const ne_ssl_certificate *cert);

       void ne_ssl_set_verify (ne_session *session, ne_ssl_verify_fn verify_fn, void *userdata);

DESCRIPTION

       To  enable manual SSL certificate verification, a callback can be registered using ne_ssl_set_verify. If such a callback is not registered,
       when a connection is established to an SSL server which does not present a certificate signed by a trusted CA  (see  ne_ssl_trust_cert(3)),
       or if the certificate presented is invalid in some way, the connection will fail.

       When  the callback is invoked, the failures parameter gives a bitmask indicating in what way the automatic certificate verification failed.
       The value is equal to the bit-wise OR of one or more of the following constants (and is guaranteed to be non-zero):

       NE_SSL_NOTYETVALID
	      The certificate is not yet valid.

       NE_SSL_EXPIRED
	      The certificate has expired.

       NE_SSL_IDMISMATCH
	      The hostname used for the session does not match the hostname to which the certificate was issued.

       NE_SSL_UNTRUSTED
	      The Certificate Authority which signed the certificate is not trusted.

       Note that if either of theNE_SSL_IDMISMATCH orNE_SSL_UNTRUSTED failures is given, the connection may have been intercepted by a third  par-
       ty, and must not be presumed to be ``secure''.

       The  cert parameter passed to the callback represents the certificate which was presented by the server. If the server presented a chain of
       certificates, the chain can be accessed using ne_ssl_cert_signedby(3). The cert object given is not valid after the callback returns.

RETURN VALUE

       The verification callback must return zero to indicate that the certificate should be trusted; and non-zero otherwise (in which	case,  the
       connection will fail).

EXAMPLES

       The  following code implements an example verification callback, using the dump_cert function from ne_ssl_cert_subject(3) to display certi-
       fication information. Notice that the hostname of the server used for the session is passed as theuserdata parameter to the callback.

       static int
       my_verify(void *userdata, int failures, const ne_ssl_certificate *cert)
       {
	 const char *hostname = userdata;

	 dump_cert(cert);

	 puts("Certificate verification failed - the connection may have been "
	      "intercepted by a third party!");

	 if (failures & NE_SSL_IDMISMATCH) {
	   const char *id = ne_ssl_cert_identity(cert);
	   if (id)
	     printf("Server certificate was issued to '%s' not '%s'.
",
		    id, hostname);
	   else
	     printf("The certificate was not issued for '%s'
", hostname);
	 }

	 if (failures & NE_SSL_UNTRUSTED)
	   puts("The certificate is not signed by a trusted Certificate Authority.");

	 /* ... check for validity failures ... */

	 if (prompt_user())
	   return 1; /* fail verification */
	 else
	   return 0; /* trust the certificate anyway */
       }

       int
       main(...)
       {
	 ne_session *sess = ne_session_create("https", "some.host.name", 443);
	 ne_ssl_set_verify(sess, my_verify, "some.host.name");
	 ...
       }

SEE ALSO

       ne_ssl_trust_cert(3), ne_ssl_readable_dname(3), ne_ssl_cert_subject(3)

AUTHOR

       Joe Orton <neon@webdav.org>.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +--------------------+-----------------+
       |  ATTRIBUTE TYPE    | ATTRIBUTE VALUE |
       +--------------------+-----------------+
       |Availability	    | SUNWneon	      |
       +--------------------+-----------------+
       |Interface Stability | Volatile	      |
       +--------------------+-----------------+
NOTES

       Source for Neon is available on http://opensolaris.org.

neon 0.25.5							  20 January 2006					      NE_SSL_SET_VERIFY(3)