1SUDO_LOGSRVD(8) BSD System Manager's Manual SUDO_LOGSRVD(8)
2
4 sudo_logsrvd — sudo event and I/O log server
5
7 sudo_logsrvd [-hnV] [-f file] [-R percentage]
8
10 sudo_logsrvd is a high-performance log server that accepts event and I/O
11 logs from sudo. It can be used to implement centralized logging of sudo
12 logs. The server has two modes of operation: local and relay. By de‐
13 fault, sudo_logsrvd stores the logs locally but it can also be configured
14 to relay them to another server that supports the sudo_logsrv.proto(5)
15 protocol.
16 When not relaying, event log entries may be logged either via syslog(3)
18 or to a local file. I/O Logs stored locally by sudo_logsrvd can be re‐
19 played via the sudoreplay(8) utility in the same way as logs generated
20 directly by the sudoers plugin.
21 The server also supports restarting interrupted log transfers. To dis‐
23 tinguish completed I/O logs from incomplete ones, the I/O log timing file
24 is set to be read-only when the log is complete.
25 Configuration parameters for sudo_logsrvd may be specified in the
27 sudo_logsrvd.conf(5) file or the file specified via the -f option.
28 sudo_logsrvd rereads its configuration file when it receives SIGHUP and
30 writes server state to the debug file (if one is configured) when it re‐
31 ceives SIGUSR1.
32 The options are as follows:
34 -f file, --file=file
36 Read configuration from file instead of the default,
37 /etc/sudo_logsrvd.conf.
38 -h, --help Display a short help message to the standard output and exit.
40 -n, --no-fork
42 Run sudo_logsrvd in the foreground instead of detaching from
43 the terminal and becoming a daemon.
44 -R percentage, --random-drop=percentage
46 For each message, there is a percentage chance that the
47 server will drop the connection. This is only intended for
48 debugging the ability of a client to restart a connection.
49 -V, --version
51 Print the sudo_logsrvd version and exit.
52 Securing server connections
54 The I/O log data sent to sudo_logsrvd may contain sensitive information
55 such as passwords and should be secured using Transport Layer Security
56 (TLS). Doing so requires having a signed certificate on the server and,
57 if tls_checkpeer is enabled in sudo_logsrvd.conf(5), a signed certificate
58 on the client as well.
59 The certificates can either be signed by a well-known Certificate Author‐
61 ity (CA), or a private CA can be used. Instructions for creating a pri‐
62 vate CA are included below in the EXAMPLES section.
63 Debugging sudo_logsrvd
65 sudo_logsrvd supports a flexible debugging framework that is configured
66 via Debug lines in the sudo.conf(5) file.
67 For more information on configuring sudo.conf(5), please refer to its
69 manual.
70
72 /etc/sudo.conf Sudo front end configuration
73 /etc/sudo_logsrvd.conf Sudo log server configuration file
75 /var/log/sudo_logsrvd/incoming
77 Directory where new journals are stored when
78 the store_first relay setting is enabled.
79 /var/log/sudo_logsrvd/outgoing
81 Directory where completed journals are stored
82 when the store_first relay setting is enabled.
83 /var/log/sudo-io Default I/O log file location
85 /run/sudo/sudo_logsrvd.pid
87 Process ID file for sudo_logsrvd
88
90 Creating self-signed certificates
91 Unless you are using certificates signed by a well-known Certificate Au‐
92 thority (or a local enterprise CA), you will need to create your own CA
93 that can sign the certificates used by sudo_logsrvd, sudo_sendlog, and
94 the sudoers plugin. The following steps use the openssl(1) command to
95 create keys and certificates.
96 Initial setup
98 First, we need to create a directory structure to store the files for the
99 CA. We'll create a new directory hierarchy in /etc/ssl/sudo for this
100 purpose.
101 # mkdir /etc/ssl/sudo
103 # cd /etc/ssl/sudo
104 # mkdir certs csr newcerts private
105 # chmod 700 private
106 # touch index.txt
107 # echo 1000 > serial
108 The serial and index.txt files are used to keep track of signed certifi‐
110 cates.
111 Next, we need to make a copy of the openssl.conf file and customize it
113 for our new CA. The path to openssl.cnf is system-dependent but
114 /etc/ssl/openssl.cnf is the most common location. You will need to ad‐
115 just the example below if it has a different location on your system.
116 # cp /etc/ssl/openssl.cnf .
118 Now edit the openssl.cnf file in the current directory and make sure it
120 contains “ca” and “CA_default” sections. Those sections should include
121 the following settings:
122 [ ca ]
124 default_ca = CA_default
125 [ CA_default ]
127 dir = /etc/ssl/sudo
128 certs = $dir/certs
129 database = $dir/index.txt
130 certificate = $dir/cacert.pem
131 serial = $dir/serial
132 If your openssl.conf file already has a “CA_default” section, you may
134 only need to modify the “dir” setting.
135 Creating the CA key and certificate
137 In order to create and sign our own certificates, we need to create a
138 private key and a certificate for the root of the CA. First, create the
139 private key and protect it with a pass phrase:
140 # openssl genrsa -aes256 -out private/cakey.pem 4096
142 # chmod 400 private/cakey.pem
143 Next, generate the root certificate, using appropriate values for the
145 site-specific fields:
146 # openssl req -config openssl.cnf -key private/cakey.pem \
148 -new -x509 -days 7300 -sha256 -extensions v3_ca \
149 -out cacert.pem
150 Enter pass phrase for private/cakey.pem:
152 You are about to be asked to enter information that will be
153 incorporated into your certificate request.
154 What you are about to enter is what is called a Distinguished Name
155 or a DN.
156 There are quite a few fields but you can leave some blank.
157 For some fields there will be a default value,
158 If you enter '.', the field will be left blank.
159 -----
160 Country Name (2 letter code) [AU]:US
161 State or Province Name (full name) [Some-State]:Colorado
162 Locality Name (eg, city) []:
163 Organization Name (eg, company) [Internet Widgits Pty Ltd]:sudo
164 Organizational Unit Name (eg, section) []:sudo Certificate Authority
165 Common Name (e.g., server FQDN or YOUR name) []:sudo Root CA
166 Email Address []:
167 # chmod 444 cacert.pem
169 Finally, verify the root certificate:
171 # openssl x509 -noout -text -in cacert.pem
173 Creating and signing certificates
175 The server and client certificates will be signed by the previously cre‐
176 ated root CA. Usually, the root CA is not used to sign server/client
177 certificates directly. Instead, intermediate certificates are created
178 and signed with the root CA and the intermediate certs are used to sign
179 CSRs (Certificate Signing Request). In this example we'll skip this part
180 for simplicity's sake and sign the CSRs with the root CA.
181 First, generate the private key without a pass phrase.
183 # openssl genrsa -out private/logsrvd_key.pem 2048
185 # chmod 400 private/logsrvd_key.pem
186 Next, create a certificate signing request (CSR) for the server's cer‐
188 tificate. The organization name must match the name given in the root
189 certificate. The common name should be either the server's IP address or
190 a fully qualified domain name.
191 # openssl req -config openssl.cnf -key private/logsrvd_key.pem -new \
193 -sha256 -out csr/logsrvd_csr.pem
194 Enter pass phrase for private/logsrvd_key.pem:
196 You are about to be asked to enter information that will be
197 incorporated into your certificate request.
198 What you are about to enter is what is called a Distinguished Name
199 or a DN.
200 There are quite a few fields but you can leave some blank.
201 For some fields there will be a default value,
202 If you enter '.', the field will be left blank.
203 -----
204 Country Name (2 letter code) [AU]:US
205 State or Province Name (full name) [Some-State]:Colorado
206 Locality Name (eg, city) []:
207 Organization Name (eg, company) [Internet Widgits Pty Ltd]:sudo
208 Organizational Unit Name (eg, section) []:sudo log server
209 Common Name (e.g., server FQDN or YOUR name) []:logserver.example.com
210 Email Address []:
211 Please enter the following 'extra' attributes
213 to be sent with your certificate request
214 A challenge password []:
215 An optional company name []:
216 Now sign the CSR that was just created:
218 # openssl ca -config openssl.cnf -days 375 -notext -md sha256 \
220 -in csr/logsrvd_csr.pem -out certs/logsrvd_cert.pem
221 Using configuration from openssl.cnf
223 Enter pass phrase for ./private/cakey.pem:
224 Check that the request matches the signature
225 Signature ok
226 Certificate Details:
227 Serial Number: 4096 (0x1000)
228 Validity
229 Not Before: Nov 11 14:05:05 2019 GMT
230 Not After : Nov 20 14:05:05 2020 GMT
231 Subject:
232 countryName = US
233 stateOrProvinceName = Colorado
234 organizationName = sudo
235 organizationalUnitName = sudo log server
236 commonName = logserve.example.com
237 X509v3 extensions:
238 X509v3 Basic Constraints:
239 CA:FALSE
240 Netscape Comment:
241 OpenSSL Generated Certificate
242 X509v3 Subject Key Identifier:
243 4C:50:F9:D0:BE:1A:4C:B2:AC:90:76:56:C7:9E:16:AE:E6:9E:E5:B5
244 X509v3 Authority Key Identifier:
245 keyid:D7:91:24:16:B1:03:06:65:1A:7A:6E:CF:51:E9:5C:CB:7A:95:3E:0C
246 Certificate is to be certified until Nov 20 14:05:05 2020 GMT (375 days)
248 Sign the certificate? [y/n]:y
249 1 out of 1 certificate requests certified, commit? [y/n]y
251 Write out database with 1 new entries
252 Data Base Updated
253 Finally, verify the new certificate:
255 # openssl verify -CAfile cacert.pem certs/logsrvd_cert.pem
257 certs/logsrvd_cert.pem: OK
258 The /etc/ssl/sudo/certs directory now contains a signed and verified cer‐
260 tificate for use with sudo_logsrvd.
261 To generate a client certificate, repeat the process above using a dif‐
263 ferent file name.
264 Configuring sudo_logsrvd to use TLS
266 To use TLS for client/server communication, both sudo_logsrvd and the
267 sudoers plugin need to be configured to use TLS. Configuring
268 sudo_logsrvd for TLS requires the following settings, assuming the same
269 path names used earlier:
270 # Listen on port 30344 for TLS connections to any address.
272 listen_address = *:30344(tls)
273 # Path to the certificate authority bundle file in PEM format.
275 tls_cacert = /etc/ssl/sudo/cacert.pem
276 # Path to the server's certificate file in PEM format.
278 tls_cert = /etc/ssl/sudo/certs/logsrvd_cert.pem
279 # Path to the server's private key file in PEM format.
281 tls_key = /etc/ssl/sudo/private/logsrvd_key.pem
282 The root CA cert (cacert.pem) must be installed on the system running
284 sudo_logsrvd. If peer authentication is enabled on the client, a copy of
285 cacert.pem must be present on the client system too.
286
288 sudo.conf(5), sudo_logsrvd.conf(5), sudoers(5), sudo(8), sudo_sendlog(8),
289 sudoreplay(8)
290
292 Many people have worked on sudo over the years; this version consists of
293 code written primarily by:
294 Todd C. Miller
296 See the CONTRIBUTORS file in the sudo distribution
298 (https://www.sudo.ws/contributors.html) for an exhaustive list of people
299 who have contributed to sudo.
300
302 If you feel you have found a bug in sudo_logsrvd, please submit a bug re‐
303 port at https://bugzilla.sudo.ws/
304
306 Limited free support is available via the sudo-users mailing list, see
307 https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
308 the archives.
309
311 sudo_logsrvd is provided “AS IS” and any express or implied warranties,
312 including, but not limited to, the implied warranties of merchantability
313 and fitness for a particular purpose are disclaimed. See the LICENSE
314 file distributed with sudo or https://www.sudo.ws/license.html for com‐
315 plete details.
316Sudo 1.9.7p2 April 29, 2021 Sudo 1.9.7p2