Sudo Log Server Configuration Manual
NAME
sudo_logsrvd.conf
—
configuration for
sudo_logsrvd
DESCRIPTION
The sudo_logsrvd.conf
file is used to
configure the sudo_logsrvd
log server. It uses an
INI-style format made up of sections in square brackets and “key =
value” pairs specific to each section below the section name.
Depending on the key, values may be integers, booleans or strings. Section
and key names are not case sensitive, but values are.
The pound sign (‘#
’) is used
to indicate a comment. Both the comment character and any text after it, up
to the end of the line, are ignored. Lines beginning with a semi-colon
(‘;
’) are also ignored.
Long lines can be continued with a backslash
(‘\
’) as the last character on the
line. Note that leading white space is removed from the beginning of lines
even when the continuation character is used.
The EXAMPLES section contains a
copy of the default sudo_logsrvd.conf
file.
The following configuration sections are recognized:
- server
- iolog
- eventlog
- syslog
- logfile
Each section is described in detail below.
server
The server section configures the address and port the server will listen on. The following keys are recognized:
- listen_address = host[:port][(tls)]
- The host name or IP address, optional port to listen on and an optional
Transport Layer Security (TLS) flag in parentheses.
The host may be a host name, an IPv4 address, an IPv6 address in square brackets or the wild card entry ‘
*
’. A host setting of ‘*
’ will causesudo_logsrvd
to listen on all configured network interfaces.If the optional tls flag is present,
sudo_logsrvd
will secure the connection with TLS version 1.2 or 1.3. Versions of TLS prior to 1.2 are not supported. See sudo_logsrvd(8) for details on generating TLS keys and certificates.If a port is specified, it may either be a port number or a known service name as defined by the system service name database. If no port is specified, port 30343 will be used for plaintext connections and port 30344 will be used for TLS connections.
The default value is:
listen_address = *:30343 listen_address = *:30344(tls)
- pid_file = path
- The path to the file containing the process ID of the running
sudo_logsrvd
. This file is not created whensudo_logsrvd
is run with the-n
option. The default value is /var/run/sudo/sudo_logsrvd.pid. - tcp_keepalive = boolean
- If true,
sudo_logsrvd
will enable the TCP keepalive socket option on the client connection. This enables the periodic transmission of keepalive messages to the client. If the client does not respond to a message, the connection will be closed. - timeout = number
- The amount of time, in seconds,
sudo_logsrvd
will wait for the client to respond. A value of 0 will disable the timeout. The default value is 30. - tls_cacert = path
- The path to a certificate authority bundle file, in PEM format, to use instead of the system's default certificate authority database when authenticating clients. The default is to use /etc/ssl/sudo/cacert.pem if it exists, otherwise the system's default certificate authority database is used.
- tls_cert = path
- The path to the server's certificate file, in PEM format. The default value is /etc/ssl/sudo/certs/logsrvd_cert.pem.
- tls_checkpeer = bool
- If true, client certificates will be validated by the server; clients
without a valid certificate will be unable to connect. If false, no
validation of client certificates will be performed. It true and client
certificates are created using a private certificate authority, the
tls_cacert
setting must be set to a CA bundle that contains the CA certificate used
to generate the client certificate. The default value is
false
. - tls_ciphers_v12 = string
- A list of ciphers to use for connections secured by TLS version 1.2 only,
separated by a colon ‘
:
’. See the CIPHER LIST FORMAT section in openssl-ciphers(1) for full details. The default value isHIGH:!aNULL
which consists of encryption cipher suites with key lengths larger than 128 bits, and some cipher suites with 128-bit keys. Cipher suites that offer no authentication are excluded. - tls_ciphers_v13 = string
- A list of ciphers to use for connections secured by TLS version 1.3 only,
separated by a colon ‘
:
’. Supported cipher suites depend on the version of OpenSSL used, but should include the following:- TLS_AES_128_GCM_SHA256
- TLS_AES_256_GCM_SHA384
- TLS_CHACHA20_POLY1305_SHA256
- TLS_AES_128_CCM_SHA256
- TLS_AES_128_CCM_8_SHA256
The default cipher suite is TLS_AES_256_GCM_SHA384.
- tls_dhparams = path
- The path to a file containing custom Diffie-Hellman parameters in PEM
format. This file can be created with the following command:
openssl dhparam -out /etc/sudo_logsrvd_dhparams.pem 2048
By default,
sudo_logsrvd
will use the OpenSSL defaults for Diffie-Hellman key generation. - tls_key = path
- The path to the server's private key file, in PEM format. The default value is /etc/ssl/sudo/private/logsrvd_key.pem.
- tls_verify = bool
- If true, the server certificate will be verified at startup and clients will authenticate the server by verifying its certificate and identity. If false, no verification is performed of the server certificate by the server or the client. When using self-signed certificates without a certificate authority, this setting should be set to false. The default value is true.
iolog
The iolog section configures I/O log parameters. These settings are identical to the I/O configuration in sudoers(5). The following keys are recognized:
- iolog_compress = boolean
- If set, I/O logs will be compressed using
zlib. Enabling
compression can make it harder to view the logs in real-time as the
program is executing due to buffering. The default value is
false
. - iolog_dir = path
- The top-level directory to use when constructing the path name for the I/O
log directory. The session sequence number, if any, is stored in the
directory. The default value is /var/log/sudo-io.
The following percent (‘
%
’) escape sequences are supported:%{seq}
- expanded to a monotonically increasing base-36 sequence number, such as 0100A5, where every two digits are used to form a new directory, e.g., 01/00/A5
%{user}
- expanded to the invoking user's login name
%{group}
- expanded to the name of the invoking user's real group-ID
%{runas_user}
- expanded to the login name of the user the command will be run as (e.g., root)
%{runas_group}
- expanded to the group name of the user the command will be run as (e.g., wheel)
%{hostname}
- expanded to the local host name without the domain name
%{command}
- expanded to the base name of the command being run
In addition, any escape sequences supported by the system's strftime(3) function will be expanded.
To include a literal ‘
%
’ character, the string ‘%%
’ should be used. - iolog_file = path
- The path name, relative to iolog_dir, in which to store
I/O logs. Note that iolog_file may contain directory
components. The default value is
%{seq}
.See the iolog_dir setting above for a list of supported percent (‘
%
’) escape sequences.In addition to the escape sequences, path names that end in six or more
X
s will have theX
s replaced with a unique combination of digits and letters, similar to the mktemp(3) function.If the path created by concatenating iolog_dir and iolog_file already exists, the existing I/O log file will be truncated and overwritten unless iolog_file ends in six or more
X
s. - iolog_flush = boolean
- If set, I/O log data is flushed to disk after each write instead of
buffering it. This makes it possible to view the logs in real-time as the
program is executing but may significantly reduce the effectiveness of I/O
log compression. The default value is
true
. - iolog_group = name
- The group name to look up when setting the group-ID on new I/O log files and directories. If iolog_group is not set, the primary group-ID of the user specified by iolog_user is used. If neither iolog_group nor iolog_user are set, I/O log files and directories are created with group-ID 0.
- iolog_mode = mode
- The file mode to use when creating I/O log files. Mode bits for read and
write permissions for owner, group or other are honored, everything else
is ignored. The file permissions will always include the owner read and
write bits, even if they are not present in the specified mode. When
creating I/O log directories, search (execute) bits are added to match the
read and write bits specified by
iolog_mode.
The default value is
0600
. - iolog_user = name
- The user name to look up when setting the owner of new I/O log files and directories. If iolog_group is set, it will be used instead of the user's primary group-ID. By default, I/O log files and directories are created with user and group-ID 0.
- maxseq = number
- The maximum sequence number that will be substituted for the
“
%{seq}
” escape in the I/O log file (see the iolog_dir description above for more information). While the value substituted for “%{seq}
” is in base 36, maxseq itself should be expressed in decimal. Values larger than 2176782336 (which corresponds to the base 36 sequence number “ZZZZZZ”) will be silently truncated to 2176782336. The default value is 2176782336.
eventlog
The eventlog section configures how (and if) security policy events are logged.
- log_type = string
- Where to log accept, reject and alert events reported by the policy. Supported values are syslog, logfile, and none. The default value is syslog.
- log_format = string
- The event log format. Supported log formats are “sudo” for traditional sudo-style logs and “json” for JSON-format logs. The JSON log entries contain the full contents of the accept, reject and alert messages. The default value is sudo.
syslog
The syslog section configures how events are logged via syslog(3).
- facility = string
- Syslog facility if syslog is being used for logging. Defaults to
auth
.The following syslog facilities are supported: authpriv (if your OS supports it), auth, daemon, user, local0, local1, local2, local3, local4, local5, local6, and local7.
- accept_priority = string
- Syslog priority to use when the user is allowed to run a command and
authentication is successful. Defaults to
notice
.The following syslog priorities are supported: alert, crit, debug, emerg, err, info, notice, warning, and none. Setting it to a value of none will disable logging of successful commands.
- reject_priority = string
- Syslog priority to use when the user is not allowed to run a command or
when authentication is unsuccessful. Defaults to
alert
.See accept_priority for the list of supported syslog priorities.
- alert_priority = string
- Syslog priority to use for event log alert messages received from the
client. Defaults to
alert
.See accept_priority for the list of supported syslog priorities.
- maxlen = number
- On many systems, syslog(3) has a relatively small log buffer. IETF RFC 5424 states
that syslog servers must support messages of at least 480 bytes and should
support messages up to 2048 bytes. By default,
sudo_logsrvd
creates log messages up to 960 bytes which corresponds to the historic BSD syslog implementation which used a 1024 byte buffer to store the message, date, hostname and program name.To prevent syslog messages from being truncated,
sudo_logsrvd
will split up sudo-style log messages that are larger than maxlen bytes. When a message is split, additional parts will include the string “(command continued)” after the user name and before the continued command line arguments. JSON-format log entries are never split and are not affected by maxlen.
logfile
The logfile section consists of settings related to logging to a plain file (not syslog).
- path = string
- The path to the file-based event log. This path must be fully-qualified and start with a ‘/’ character. The default value is /var/log/sudo.log.
- time_format = string
- The string used when formatting the date and time for file-based event
logs. Formatting is performed via the system's
strftime(3) function so
any escape sequences supported by that function will be expanded. The
default value is “
%h %e %T
” which produces dates like “Oct 3 07:15:24” in the C locale.
FILES
- /etc/sudo_logsrvd.conf
- Sudo log server configuration file
EXAMPLES
# # sudo logsrv configuration #[server] # The host name or IP address and port to listen on with an optional TLS # flag. If no port is specified, port 30343 will be used for plaintext # connections and port 30344 will be used to TLS connections. # The following forms are accepted: # listen_address = hostname(tls) # listen_address = hostname:port(tls) # listen_address = IPv4_address(tls) # listen_address = IPv4_address:port(tls) # listen_address = IPv6_address # listen_address = [IPv6_address]:port(tls) # # The (tls) suffix should be omitted for plaintext connections. # # Multiple listen_address settings may be specified. # The default is to listen on all addresses. #listen_address = *:30343 #listen_address = *:30344(tls)
# The file containing the ID of the running sudo_logsrvd process. #pid_file = /var/run/sudo/sudo_logsrvd.pid
# If set, enable the SO_KEEPALIVE socket option on the connected socket. #tcp_keepalive = true
# The amount of time, in seconds, the server will wait for the client to # respond. A value of 0 will disable the timeout. The default value is 30. #timeout = 30
# If set, server certificate will be verified at server startup and # also connecting clients will perform server authentication by # verifying the server’s certificate and identity. #tls_verify = true
# Whether to verify client certificates for TLS connections. # By default client certs are not checked. #tls_checkpeer = false
# Path to the certificate authority bundle file in PEM format. # Required if ’tls_verify’ or ’tls_checkpeer’ is set. #tls_cacert = /etc/ssl/sudo/cacert.pem
# Path to the server’s certificate file in PEM format. # Required for TLS connections. #tls_cert = /etc/ssl/sudo/certs/logsrvd_cert.pem
# Path to the server’s private key file in PEM format. # Required for TLS connections. #tls_key = /etc/ssl/sudo/private/logsrvd_key.pem
# TLS cipher list (see "CIPHER LIST FORMAT" in the openssl-ciphers manual). # NOTE that this setting is only effective if the negotiated protocol # is TLS version 1.2. # The default cipher list is HIGH:!aNULL. #tls_ciphers_v12 = HIGH:!aNULL
# TLS cipher list if the negotiated protocol is TLS version 1.3. # The default cipher list is TLS_AES_256_GCM_SHA384. #tls_ciphers_v13 = TLS_AES_256_GCM_SHA384
# Path to the Diffie-Hellman parameter file in PEM format. # If not set, the server will use the OpenSSL defaults. #tls_dhparams = /etc/ssl/sudo/logsrvd_dhparams.pem
[iolog] # The top-level directory to use when constructing the path name for the # I/O log directory. The session sequence number, if any, is stored here. #iolog_dir = /var/log/sudo-io
# The path name, relative to iolog_dir, in which to store I/O logs. # Note that iolog_file may contain directory components. #iolog_file = %{seq}
# If set, I/O logs will be compressed using zlib. Enabling compression can # make it harder to view the logs in real-time as the program is executing. #iolog_compress = false
# If set, I/O log data is flushed to disk after each write instead of # buffering it. This makes it possible to view the logs in real-time # as the program is executing but reduces the effectiveness of compression. #iolog_flush = true
# The group to use when creating new I/O log files and directories. # If iolog_group is not set, the primary group-ID of the user specified # by iolog_user is used. If neither iolog_group nor iolog_user # are set, I/O log files and directories are created with group-ID 0. #iolog_group = wheel
# The user to use when setting the user-ID and group-ID of new I/O # log files and directories. If iolog_group is set, it will be used # instead of the user’s primary group-ID. By default, I/O log files # and directories are created with user and group-ID 0. #iolog_user = root
# The file mode to use when creating I/O log files. The file permissions # will always include the owner read and write bits, even if they are # not present in the specified mode. When creating I/O log directories, # search (execute) bits are added to match the read and write bits # specified by iolog_mode. #iolog_mode = 0600
# The maximum sequence number that will be substituted for the "%{seq}" # escape in the I/O log file. While the value substituted for "%{seq}" # is in base 36, maxseq itself should be expressed in decimal. Values # larger than 2176782336 (which corresponds to the base 36 sequence # number "ZZZZZZ") will be silently truncated to 2176782336. #maxseq = 2176782336
[eventlog] # Where to log accept, reject and alert events. # Accepted values are syslog, logfile, or none. # Defaults to syslog #log_type = syslog
# Event log format. # Currently only sudo-style event logs are supported. #log_format = sudo
[syslog] # The maximum length of a syslog payload. # On many systems, syslog(3) has a relatively small log buffer. # IETF RFC 5424 states that syslog servers must support messages # of at least 480 bytes and should support messages up to 2048 bytes. # Messages larger than this value will be split into multiple messages. #maxlen = 960
# The syslog facility to use for event log messages. # The following syslog facilities are supported: authpriv (if your OS # supports it), auth, daemon, user, local0, local1, local2, local3, # local4, local5, local6, and local7. #facility = authpriv
# Syslog priority to use for event log accept messages, when the command # is allowed by the security policy. The following syslog priorities are # supported: alert, crit, debug, emerg, err, info, notice, warning, none. #accept_priority = notice
# Syslog priority to use for event log reject messages, when the command # is not allowed by the security policy. #reject_priority = alert
# Syslog priority to use for event log alert messages reported by the # client. #alert_priority = alert
[logfile] # The path to the file-based event log. # This path must be fully-qualified and start with a ‘/’ character. #path = /var/log/sudo
# The format string used when formatting the date and time for # file-based event logs. Formatting is performed via strftime(3) so # any format string supported by that function is allowed. #time_format = %h %e %T
SEE ALSO
strftime(3), sudo.conf(5), sudoers(5), sudo(8), sudo_logsrvd(8)
HISTORY
See the HISTORY file in the sudo
distribution (https://www.sudo.ws/history.html) for a brief history of
sudo.
AUTHORS
Many people have worked on sudo
over the
years; this version consists of code written primarily by:
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
,
please submit a bug report 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
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
complete details.