nbdkit_peer_tls_dn(3)

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.

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