Provided by: sudo_1.9.15p5-3ubuntu5_amd64 bug

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.
     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
        relay
        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 cause sudo_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)
           which will listen on all configured network interfaces for both plaintext and TLS
           connections.  Multiple listen_address lines may be specified to listen on more than
           one port or interface.

     server_log = string
           Where to log server warning and error messages.  Supported values are none, stderr,
           syslog, or a path name beginning with the ‘/’ character.  A value of stderr is only
           effective when used in conjunction with the -n option.  The default value is syslog.

     pid_file = path
           The path to the file containing the process ID of the running sudo_logsrvd.  If set to
           an empty value, or if sudo_logsrvd is run with the -n option, no pid_file will be
           created.  If pid_file refers to a symbolic link, it will be ignored.  The default
           value is /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 in time, the connection will be
           closed.  Defaults to true.

     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 sudo_logsrvd; 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 is “HIGH:!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, sudo_logsrvd will validate its own certificate at startup time or when the
           configuration is changed.  If false, no verification is performed of the server
           certificate.  When using self-signed certificates without a certificate authority,
           this setting should be set to false.  The default value is true.

   relay
     The relay section configures the optional logsrv relay host and port the server will connect
     to.  The TLS configuration keys are optional, by default the corresponding keys in the
     server section will be used.  They are only present in this section to make it possible for
     the relay connection to use a different set of TLS parameters from the client-facing server.
     The following keys are recognized:

     connect_timeout = number
           The amount of time, in seconds, sudo_logsrvd will wait for the connection to a
           relay_host (see below) to complete.  Once the connection is complete, the timeout
           setting controls the amount of time sudo_logsrvd will wait for the relay to respond.
           A value of 0 will disable the timeout.  The default value is 30.

     relay_dir = path
           The directory in which log messages are temporarily stored before they are sent to the
           relay host.  Messages are stored in the wire format specified by sudo_logsrv.proto(5)
           The default value is /var/log/sudo_logsrvd.

     relay_host = host[:port][(tls)]
           The relay host name or IP address, optional port to connect to and an optional
           Transport Layer Security (TLS) flag in parentheses.  The syntax is identical to
           listen_address in the server section with one exception: the wild card ‘*’ syntax is
           not supported.

           When this setting is enabled, messages from the client will be forwarded to one of the
           specified relay hosts instead of being stored locally.  The host could be running an
           instance of sudo_logsrvd or another server that supports the sudo_logsrv.proto(5)
           protocol.

           If multiple relay_host lines are specified, the first available relay host will be
           used.

     retry_interval = number
           The number of seconds to wait after a connection error before making a new attempt to
           forward a message to a relay host.  The default value is 30.

     store_first = boolean
           If true, sudo_logsrvd will store logs locally before relaying them.  Once the log is
           complete, a connection to the relay host is opened and the log is relayed.  If the
           network connection is interrupted before the log can be fully transferred, it will be
           retransmitted later.  The default is to relay logs in real-time.

     tcp_keepalive = boolean
           If true, sudo_logsrvd will enable the TCP keepalive socket option on the relay
           connection.  This enables the periodic transmission of keepalive messages to the relay
           server.  If the relay does not respond to a message in time, the connection will be
           closed.

     timeout = number
           The amount of time, in seconds, sudo_logsrvd will wait for the relay server to respond
           after a connection has succeeded.  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 the value specified in the server section, or the system's default
           certificate authority database if no value is set.

     tls_cert = path
           The path to the server's certificate file, in PEM format.  The default is to use the
           value specified in the server section.

     tls_checkpeer = bool
           If true, the relay host's certificate will be validated by sudo_logsrvd; connections
           to a relay without a valid certificate will fail.  If false, no validation of relay
           certificates will be performed.  It true and relay 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 relay certificate.  The default is to
           use the value specified in the server section.

     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 is to use the value specified in the server section.

     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, see the
           server section for more information.  The default is to use the value specified in the
           server section.

     tls_dhparams = path
           The path to a file containing custom Diffie-Hellman parameters in PEM format.  The
           default is to use the value specified in the server section.

     tls_key = path
           The path to the server's private key file, in PEM format.  The default is to use the
           value specified in the server section.

     tls_verify = bool
           If true, the server's certificate used for relaying will be verified at startup.  If
           false, no verification is performed of the server certificate.  When using self-signed
           certificates without a certificate authority, this setting should be set to false.
           The default is to use the value specified in the server section.

   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.  It is possible for
           iolog_file to 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 Xs will have
           the Xs 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 Xs.

     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.  I/O logs are
           always flushed before sending a commit point to the client regardless of this setting.
           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.

     log_passwords = bool
           Most programs that require a user's password will disable echo before reading the
           password to avoid displaying the plaintext password on the screen.  However, if
           terminal input is being logged, the password will still be present in the I/O log.  If
           log_passwords is set to false, sudo_logsrvd will attempt to prevent passwords from
           being logged.  It does this by using the regular expressions in passprompt_regex to
           match a password prompt in the terminal output buffer.  When a match is found, input
           characters in the I/O log will be replaced with ‘*’ until either a line feed or
           carriage return is found in the terminal input or a new terminal output buffer is
           received.  If, however, a program displays characters as the user types them (such as
           sudo when the pwfeedback option is set), only the first character of the password will
           be replaced in the I/O log.  The default value is true.

     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.

     passprompt_regex = string
           One or more POSIX extended regular expressions used to match password prompts in the
           terminal output when log_passwords is disabled.  As an extension, if the regular
           expression begins with “(?i)”, it will be matched in a case-insensitive manner.
           Multiple passprompt_regex settings may be specified.  Each regular expression is
           limited to 1024 characters.  The default value is “[Pp]assword[: ]*”.

   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_exit = boolean
           If true, sudo_logsrvd will log an event when a command exits or is terminated by a
           signal.  Defaults to false.

     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, exit 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 authpriv.

           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.

     server_facility = string
           Syslog facility if syslog is being used for server warning messages.  See above for a
           list of supported facilities.  Defaults to daemon

   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 daemon 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](tls)
     #   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 = /run/sudo/sudo_logsrvd.pid

     # Where to log server warnings: none, stderr, syslog, or a path name.
     #server_log = syslog

     # If true, enable the SO_KEEPALIVE socket option on client connections.
     # Defaults to true.
     #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 true, the server will validate its own certificate at startup.
     # Defaults to true.
     #tls_verify = true

     # If true, client certificates will be validated by the server;
     # clients without a valid certificate will be unable to connect.
     # By default, client certs are not checked.
     #tls_checkpeer = false

     # Path to a certificate authority bundle file in PEM format to use
     # instead of the system's default certificate authority database.
     #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).
     # 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

     [relay]
     # The host name or IP address and port to send logs to in relay mode.
     # The syntax is identical to listen_address with the exception of
     # the wild card ('*') syntax.  When this setting is enabled, logs will
     # be relayed to the specified host instead of being stored locally.
     # This setting is not enabled by default.
     #relay_host = relayhost.dom.ain
     #relay_host = relayhost.dom.ain(tls)

     # The amount of time, in seconds, the server will wait for a connection
     # to the relay server to complete.  A value of 0 will disable the timeout.
     # The default value is 30.
     #connect_timeout = 30

     # The directory to store messages in before they are sent to the relay.
     # Messages are stored in wire format.
     # The default value is /var/log/sudo_logsrvd.
     #relay_dir = /var/log/sudo_logsrvd

     # The number of seconds to wait after a connection error before
     # making a new attempt to forward a message to a relay host.
     # The default value is 30.
     #retry_interval = 30

     # Whether to store the log before relaying it.  If true, enable store
     # and forward mode.  If false, the client connection is immediately
     # relayed.  Defaults to false.
     #store_first = true

     # If true, enable the SO_KEEPALIVE socket option on relay connections.
     # Defaults to true.
     #tcp_keepalive = true

     # The amount of time, in seconds, the server will wait for the relay to
     # respond.  A value of 0 will disable the timeout.  The default value is 30.
     #timeout = 30

     # If true, the server's relay certificate will be verified at startup.
     # The default is to use the value in the [server] section.
     #tls_verify = true

     # Whether to verify the relay's certificate for TLS connections.
     # The default is to use the value in the [server] section.
     #tls_checkpeer = false

     # Path to a certificate authority bundle file in PEM format to use
     # instead of the system's default certificate authority database.
     # The default is to use the value in the [server] section.
     #tls_cacert = /etc/ssl/sudo/cacert.pem

     # Path to the server's certificate file in PEM format.
     # The default is to use the certificate in the [server] section.
     #tls_cert = /etc/ssl/sudo/certs/logsrvd_cert.pem

     # Path to the server's private key file in PEM format.
     # The default is to use the key in the [server] section.
     #tls_key = /etc/ssl/sudo/private/logsrvd_key.pem

     # TLS cipher list (see "CIPHER LIST FORMAT" in the openssl-ciphers manual).
     # this setting is only effective if the negotiated protocol is TLS version
     # 1.2.  The default is to use the value in the [server] section.
     #tls_ciphers_v12 = HIGH:!aNULL

     # TLS cipher list if the negotiated protocol is TLS version 1.3.
     # The default is to use the value in the [server] section.
     #tls_ciphers_v13 = TLS_AES_256_GCM_SHA384

     # Path to the Diffie-Hellman parameter file in PEM format.
     # The default is to use the value in the [server] section.
     #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.
     # It is possible for iolog_file to 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

     # If disabled, sudo_logsrvd will attempt to avoid logging plaintext
     # password in the terminal input using passprompt_regex.
     #log_passwords = true

     # 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

     # One or more POSIX extended regular expressions used to match
     # password prompts in the terminal output when log_passwords is
     # disabled.  Multiple passprompt_regex settings may be specified.
     #passprompt_regex = [Pp]assword[: ]*
     #passprompt_regex = [Pp]assword for [a-z0-9]+: *

     [eventlog]
     # Where to log accept, reject, exit, and alert events.
     # Accepted values are syslog, logfile, or none.
     # Defaults to syslog
     #log_type = syslog

     # Whether to log an event when a command exits or is terminated by a signal.
     # Defaults to false
     #log_exit = true

     # 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

     # The syslog facility to use for server warning messages.
     # Defaults to daemon.
     #server_facility = daemon

     [logfile]
     # The path to the file-based event log.
     # This path must be fully-qualified and start with a '/' character.
     #path = /var/log/sudo.log

     # 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)

AUTHORS

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

           Todd C. Miller

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

BUGS

     If you believe you have found a bug in sudo, you can 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.md file distributed with sudo or
     https://www.sudo.ws/about/license/ for complete details.