Go to main content

man pages section 3: Library Interfaces and Headers

Exit Print View

Updated: Thursday, June 13, 2019
 
 

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

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), 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 the NE_SSL_IDMISMATCH or NE_SSL_UNTRUSTED
       failures is given, the connection may have been intercepted by a third
       party, 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. 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 to display
       certification information. Notice that the hostname of the server used
       for the session is passed as the userdata 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'.\n",
                        id, hostname);
               else
                 printf("The certificate was not issued for '%s'\n", 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");
             ...
           }


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


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | library/neon     |
       +---------------+------------------+
       |Stability      | Volatile         |
       +---------------+------------------+
SEE ALSO
       ne_ssl_trust_cert, ne_ssl_readable_dname, ne_ssl_cert_subject

AUTHOR
       Joe Orton <neon@lists.manyfish.co.uk>
           Author.

COPYRIGHT
NOTES
       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from
       http://www.webdav.org/neon/neon-0.30.1.tar.gz

       Further information about this software can be found on the open source
       community website at http://www.webdav.org/neon/.



neon 0.30.1                    23 September 2014          NE_SSL_SET_VERIFY(3)