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lprng_certs(1) lprng_certs command lprng_certs(1)


lprng_certs - lprng SSL certificate management


lprng_certs option

init - make directory structure
newca - make new root CA
defaults - set new default values for certs
gen - generate user, server, or signing cert
index [dir] - index cert files
verify [cert] - verify cert file
encrypt keyfile
- set or change keyfile password


The lprng_certs program is used to manage SSL certificates for the LPRng software. There SSL certificate structure consists of a hierarchy of certificates. The LPRng software assumes that the following types of certificates will be used:

A top level or self-signed certificate.
A certificate that can be used to sign other certificates. This is signed by the root CA or another signing certificate.
A certificate used by a user to identify themselves to the lpd server.
A certificate used by the lpd server to identify themselves to the user or other lpd servers.

Signing Certificates

All of the signing certificates, including the root certificate (root CA), /etc/lprng/, are in the same directory as the root CA file. Alternately, all of the signing certs can be concatenated and put into a single file, which by convention is assumed to have the same name as the root CA file, /etc/lprng/ The ssl_ca_file, ssl_ca_path, and ssl_ca_key printcap and configuration options can be used to specify the locations of the root CA files, a directory containing the signing certificate files, and the private key file for the root CA file respectively.

The root certificate (root CA file) /etc/lprng/ has a private key file /etc/lprng/ as well. By convention, the private keys for the other signing certificate files are stored in the certificate file.

The OpenSSL software requires that this directory also contain a set of hash files which are, in effect, links to these files.

By default, all signing certificates are assumed to be in the same directory as the root certificate.

Server Certificates

The certificate used by the lpd server are kept in another directory. These files do not need to have hash links to them. By convention, the private keys for these certificate files are stored in the certificate file. The server certificate file is specified by the ssl_server_cert and has the default value /etc/lprng/ssl.server/server.crt. This file contains the cert and private key. The server certificate password file is specified by the ssl_server_password option with the default value

and contains the password used to decrypt the servers private key and use it for authentication. This key file should be read only by the lpd server.

User Certificates

The certificates used by users are kept in a separate directory in the users home directory. By convention, the private keys for these certificate files are stored in the certificate file.

The user certificate file is specified by the LPR_SSL_FILE environment variable, otherwise the ${HOME}/.lpr/client.crt is used. The password is taken from the file specified by the LPR_SSL_PASSWORD environment variable, otherwise the ${HOME}/.lpr/client.pwd file is read.


The organization of the SSL certificates used by LPRng is similar to that used by other programs such as the Apache mod_ssl support. The lprng_certs program is used to create the directory structure, create certificates for the root CA, signing, user and servers. In order to make management simple, the following support is provided.

lprng_certs init

This command creates the directories used by the lpd server. It is useful when setting up a new lpd server.

lprng_certs newca

This command creates a self-signed certificate, suitable for use as a root CA certificate. It also sets up a set of default values for other certificate creation.

lprng_certs defaults

This command is used to modify the set of default values.

The default values are listed and should be self-explanatory, except for the value of the signer certificate. By default, the root CA can be used to sign certificates. However, a signing certificate can be used as well. This allows delegation of signing authority without compromising the security of the root CA.

lprng_certs gen

This is used to generate a user, server, or signing certificate.

lprng_certs index

This is used to create the indexes for the signing certificates.

lprng_certs verify [cert]

This checks the certificate file using the Openssl openssl verify command.

lprng_certs encrypt keyfile

This removes all key information from the key file, reencrypts the key information, and the puts the encrypted key information in the file.


Option	Purpose
ssl_ca_path	directory holding the SSL signing certs
ssl_ca_file	file holding the root CA or all SSL signing certs
ssl_server_cert	cert file for the server
ssl_server_password	file containing password for server server
${HOME}/.lpr/client.crt	client certificate file
${HOME}/.lpr/client.pwd	client certificate private key password


LPR_SSL_FILE	client certificate file
LPR_SSL_PASSWORD	client certificate private key password


The following exit values are returned:

Successful completion.
An error occurred.


lpd.conf(5), lpc(8), lpd(8), checkpc(8), lpr(1), lpq(1), lprm(1), printcap(5), lpd.conf(5), pr(1), lprng_certs(1), lprng_index_certs(1).


Patrick Powell <>.


LPRng is a enhanced printer spooler system with functionality similar to the Berkeley LPR software. The LPRng developer mailing list is; subscribe by visiting or sending mail to with the word subscribe in the body.
The software is available via

2006-12-09 LPRng