NAME

       nbdkit_peer_tls_dn, nbdkit_peer_tls_issuer_dn - read the client TLS X.509 Distinguished Name

SYNOPSIS

        #include <nbdkit-plugin.h>

        char *nbdkit_peer_tls_dn (void);
        char *nbdkit_peer_tls_issuer_dn (void);

DESCRIPTION

       If all of these conditions are met:

       •   the client connects over TLS (see nbdkit-tls(1))

       •   the TLS connection is using X.509 certificates

       •   the client presents a client certificate

       •   the nbdkit --tls-verify-peer option is used

       then  these  APIs  can be used to get the Distinguished Name (DN) of the certificate or the certificate's
       issuer.  The issuer is the Certificate Authority (CA) that issued the client certificate.

       The DN is returned as a string of the form "CN=xx,O=yy,[...]C=zz" (see RFC 4514 for the exact format).

       If the DN is not available, "" is returned (this is not an error).

       nbdkit-ip-filter(1) can be used to filter client connections by the DN.

   EXAMPLE CERTIFICATE AND DISTINGUISHED NAME
       Please  see  nbdkit-tls(1)  for  details  of  how  to  generate  client  certificates.   Following  those
       instructions, if you were to generate a client certificate from this client.info input:

        country = US
        state = New York
        locality = New York
        organization = BigCo
        cn = client.example.com
        tls_www_client
        encryption_key
        signing_key

       and sign it with this Certificate Authority ca.info:

        cn = BigCo
        ca
        cert_signing_key

       then the client certificate DN would be:

        CN=client.example.com,O=BigCo,L=New York,ST=New York,C=US

       and the issuer DN would be:

        CN=BigCo

RETURN VALUE

       On  success  both of these functions return a TLS Distinguished Name as a string, or "".  The caller must
       free this string.

       If there is an error they call nbdkit_error(3) and return "NULL".

LANGUAGE BINDINGS

       In nbdkit-ocaml-plugin(3):

        NBDKit.peer_tls_dn : unit -> string
        NBDKit.peer_tls_issuer_dn : unit -> string

       In nbdkit-python-plugin(3):

        import nbdkit
        dn = nbdkit.peer_tls_dn()
        dn = nbdkit.peer_tls_issuer_dn()

HISTORY

       "nbdkit_peer_tls_dn" and "nbdkit_peer_tls_issuer_dn" were added in nbdkit 1.40.

SEE ALSO

       nbdkit(1),  nbdkit-plugin(3),  nbdkit-filter(3),  nbdkit-tls(1),  nbdkit-ip-filter(1),  nbdkit_is_tls(3),
       nbdkit_peer_name(3).

AUTHORS

       Richard W.M. Jones

COPYRIGHT

       Copyright Red Hat

LICENSE

       Redistribution  and  use in source and binary forms, with or without modification, are permitted provided
       that the following conditions are met:

       •   Redistributions of source code must retain the above copyright notice, this list  of  conditions  and
           the following disclaimer.

       •   Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
           the following disclaimer in the documentation and/or other materials provided with the distribution.

       •   Neither  the  name  of  Red  Hat  nor the names of its contributors may be used to endorse or promote
           products derived from this software without specific prior written permission.

       THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS  OR  IMPLIED  WARRANTIES,
       INCLUDING,  BUT  NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
       PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE  FOR  ANY  DIRECT,  INDIRECT,
       INCIDENTAL,  SPECIAL,  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
       ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT  LIABILITY,  OR  TORT  (INCLUDING  NEGLIGENCE  OR
       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
       DAMAGE.

nbdkit-1.42.2                                      2025-04-02                              nbdkit_peer_tls_dn(3)