SUDO_LOGSRVD(8)



SUDO_LOGSRVD(8)           BSD System Manager's Manual          SUDO_LOGSRVD(8)

NAME
     sudo_logsrvd -- sudo event and I/O log server

SYNOPSIS
     sudo_logsrvd [-hnV] [-f file] [-R percentage]

DESCRIPTION
     sudo_logsrvd is a high-performance log server that accepts event and I/O
     logs from sudo.  It can be used to implement centralized logging of sudo
     logs.  Event log entries may be logged either via syslog(3) or to a file.
     I/O Logs created by sudo_logsrvd can be replayed via the sudoreplay(8)
     utility in the same way as logs generated directly by the sudoers plugin.

     The server also supports restarting interrupted log transfers.  To dis-
     tinguish completed I/O logs from incomplete ones, the I/O log timing file
     is set to be read-only when the log is complete.

     Configuration parameters for sudo_logsrvd may be specified in the
     sudo_logsrvd.conf(5) file.

     The options are as follows:

     -f, --file  Read configuration from file instead of the default,
                 /etc/sudo_logsrvd.conf.

     -h, --help  Display a short help message to the standard output and exit.

     -n, --no-fork
                 Run sudo_logsrvd in the foreground instead of detaching from
                 the terminal and becoming a daemon.

     -R, --random-drop
                 For each message, there is a percentage chance that the
                 server will drop the connection.  This is only intended for
                 debugging the ability of a client to restart a connection.

     -V, --version
                 Print the sudo_logsrvd version and exit.

   Securing server connections
     The I/O log data sent to sudo_logsrvd may contain sensitive information
     such as passwords and should be secured using Transport Layer Security
     (TLS).  Doing so requires having a signed certificate on the server and,
     if tls_checkpeer is enabled in sudo_logsrvd.conf(5), a signed certificate
     on the client as well.

     The certificates can either be signed by a well-known Certificate Author-
     ity (CA), or a private CA can be used.  Instructions for creating a pri-
     vate CA are included below in the EXAMPLES section.

   Debugging sudo_logsrvd
     sudo_logsrvd supports a flexible debugging framework that is configured
     via Debug lines in the sudo.conf(5) file.

     For more information on configuring sudo.conf(5), please refer to its
     manual.

FILES
     /etc/sudo.conf            Sudo front end configuration

     /etc/sudo_logsrvd.conf    Sudo log server configuration file

     /var/log/sudo-io          Default I/O log file location

     /run/sudo/sudo_logsrvd.pid
                               Process ID file for sudo_logsrvd

EXAMPLES
   Creating self-signed certificates
     Unless you are using certificates signed by a well-known Certificate Au-
     thority (or a local enterprise CA), you will need to create your own CA
     that can sign the certificates used by sudo_logsrvd, sudo_sendlog, and
     the sudoers plugin.  The following steps use the openssl(1) command to
     create keys and certificates.

   Initial setup
     First, we need to create a directory structure to store the files for the
     CA.  We'll create a new directory hierarchy in /etc/ssl/sudo for this
     purpose.

           # mkdir /etc/ssl/sudo
           # cd /etc/ssl/sudo
           # mkdir certs csr newcerts private
           # chmod 700 private
           # touch index.txt
           # echo 1000 > serial

     The serial and index.txt files are used to keep track of signed certifi-
     cates.

     Next, we need to make a copy of the openssl.conf file and customize it
     for our new CA.  The path to openssl.cnf is system-dependent but
     /etc/ssl/openssl.cnf is the most common location.  You will need to ad-
     just the example below if it has a different location on your system.

           # cp /etc/ssl/openssl.cnf .

     Now edit the openssl.cnf file in the current directory and make sure it
     contains "ca" and "CA_default" sections.  Those sections should include
     the following settings:

           [ ca ]
           default_ca      = CA_default

           [ CA_default ]
           dir             = /etc/ssl/sudo
           certs           = $dir/certs
           database        = $dir/index.txt
           certificate     = $dir/cacert.pem
           serial          = $dir/serial

     If your openssl.conf file already has a "CA_default" section, you may
     only need to modify the "dir" setting.

   Creating the CA key and certificate
     In order to create and sign our own certificates, we need to create a
     private key and a certificate for the root of the CA.  First, create the
     private key and protect it with a pass phrase:

           # openssl genrsa -aes256 -out private/cakey.pem 4096
           # chmod 400 private/cakey.pem

     Next, generate the root certificate, using appropriate values for the
     site-specific fields:

           # openssl req -config openssl.cnf -key private/cakey.pem \
               -new -x509 -days 7300 -sha256 -extensions v3_ca \
               -out cacert.pem

           Enter pass phrase for private/cakey.pem:
           You are about to be asked to enter information that will be
           incorporated into your certificate request.
           What you are about to enter is what is called a Distinguished Name
           or a DN.
           There are quite a few fields but you can leave some blank.
           For some fields there will be a default value,
           If you enter '.', the field will be left blank.
           -----
           Country Name (2 letter code) [AU]:US
           State or Province Name (full name) [Some-State]:Colorado
           Locality Name (eg, city) []:
           Organization Name (eg, company) [Internet Widgits Pty Ltd]:sudo
           Organizational Unit Name (eg, section) []:sudo Certificate Authority
           Common Name (e.g., server FQDN or YOUR name) []:sudo Root CA
           Email Address []:

           # chmod 444 cacert.pem

     Finally, verify the root certificate:

           # openssl x509 -noout -text -in cacert.pem

   Creating and signing certificates
     The server and client certificates will be signed by the previously cre-
     ated root CA.  Usually, the root CA is not used to sign server/client
     certificates directly.  Instead, intermediate certificates are created
     and signed with the root CA and the intermediate certs are used to sign
     CSRs (Certificate Signing Request).  In this example we'll skip this part
     for simplicity's sake and sign the CSRs with the root CA.

     First, generate the private key without a pass phrase.

           # openssl genrsa -out private/logsrvd_key.pem 2048
           # chmod 400 private/logsrvd_key.pem

     Next, create a certificate signing request (CSR) for the server's cer-
     tificate.  The organization name must match the name given in the root
     certificate.  The common name should be either the server's IP address or
     a fully qualified domain name.

           # openssl req -config openssl.cnf -key private/logsrvd_key.pem -new \
               -sha256 -out csr/logsrvd_csr.pem

           Enter pass phrase for private/logsrvd_key.pem:
           You are about to be asked to enter information that will be
           incorporated into your certificate request.
           What you are about to enter is what is called a Distinguished Name
           or a DN.
           There are quite a few fields but you can leave some blank.
           For some fields there will be a default value,
           If you enter '.', the field will be left blank.
           -----
           Country Name (2 letter code) [AU]:US
           State or Province Name (full name) [Some-State]:Colorado
           Locality Name (eg, city) []:
           Organization Name (eg, company) [Internet Widgits Pty Ltd]:sudo
           Organizational Unit Name (eg, section) []:sudo log server
           Common Name (e.g., server FQDN or YOUR name) []:logserver.example.com
           Email Address []:

           Please enter the following 'extra' attributes
           to be sent with your certificate request
           A challenge password []:
           An optional company name []:

     Now sign the CSR that was just created:

           # openssl ca -config openssl.cnf -days 375 -notext -md sha256 \
               -in csr/logsrvd_csr.pem -out certs/logsrvd_cert.pem

           Using configuration from openssl.cnf
           Enter pass phrase for ./private/cakey.pem:
           Check that the request matches the signature
           Signature ok
           Certificate Details:
                   Serial Number: 4096 (0x1000)
                   Validity
                       Not Before: Nov 11 14:05:05 2019 GMT
                       Not After : Nov 20 14:05:05 2020 GMT
                   Subject:
                       countryName               = US
                       stateOrProvinceName       = Colorado
                       organizationName          = sudo
                       organizationalUnitName    = sudo log server
                       commonName                = logserve.example.com
                   X509v3 extensions:
                       X509v3 Basic Constraints:
                           CA:FALSE
                       Netscape Comment:
                           OpenSSL Generated Certificate
                       X509v3 Subject Key Identifier:
                           4C:50:F9:D0:BE:1A:4C:B2:AC:90:76:56:C7:9E:16:AE:E6:9E:E5:B5
                       X509v3 Authority Key Identifier:
                           keyid:D7:91:24:16:B1:03:06:65:1A:7A:6E:CF:51:E9:5C:CB:7A:95:3E:0C

           Certificate is to be certified until Nov 20 14:05:05 2020 GMT (375 days)
           Sign the certificate? [y/n]:y

           1 out of 1 certificate requests certified, commit? [y/n]y
           Write out database with 1 new entries
           Data Base Updated

     Finally, verify the new certificate:

           # openssl verify -CAfile cacert.pem certs/logsrvd_cert.pem
           certs/logsrvd_cert.pem: OK

     The /etc/ssl/sudo/certs directory now contains a signed and verified cer-
     tificate for use with sudo_logsrvd.

     To generate a client certificate, repeat the process above using a dif-
     ferent file name.

   Configuring sudo_logsrvd to use TLS
     To use TLS for client/server communication, both sudo_logsrvd and the
     sudoers plugin need to be configured to use TLS.  Configuring
     sudo_logsrvd for TLS requires the following settings, assuming the same
     path names used earlier:

           # If set, secure connections with TLS 1.2 or 1.3.
           tls = true

           # Path to the certificate authority bundle file in PEM format.
           tls_cacert = /etc/ssl/sudo/cacert.pem

           # Path to the server's certificate file in PEM format.
           tls_cert = /etc/ssl/sudo/certs/logsrvd_cert.pem

           # Path to the server's private key file in PEM format.
           tls_key = /etc/ssl/sudo/private/logsrvd_key.pem

     The root CA cert (cacert.pem) must be installed on the system running
     sudo_logsrvd.  If peer authentication is enabled on the client, a copy of
     cacert.pem must be present on the client system too.

SEE ALSO
     sudo.conf(5), sudo_logsrvd.conf(5), sudoers(5), sudo(8), sudo_sendlog(8),
     sudoreplay(8)

AUTHORS
     Many people have worked on sudo over the years; this version consists of
     code written primarily by:

           Todd C. Miller

     See the CONTRIBUTORS file in the sudo distribution
     (https://www.sudo.ws/contributors.html) for an exhaustive list of people
     who have contributed to sudo.

BUGS
     If you feel you have found a bug in sudo_logsrvd, please submit a bug re-
     port at https://bugzilla.sudo.ws/

SUPPORT
     Limited free support is available via the sudo-users mailing list, see
     https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
     the archives.

DISCLAIMER
     sudo_logsrvd is provided "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.  See the LICENSE
     file distributed with sudo or https://www.sudo.ws/license.html for com-
     plete details.

Sudo 1.9.5p2                    March 28, 2020                    Sudo 1.9.5p2

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