1PAM_TALLY2(8) Linux-PAM Manual PAM_TALLY2(8)
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6 pam_tally2 - The login counter (tallying) module
7
9 pam_tally2.so [file=/path/to/counter] [onerr=[fail|succeed]]
10 [magic_root] [even_deny_root] [deny=n] [lock_time=n]
11 [unlock_time=n] [root_unlock_time=n] [serialize] [audit]
12 [silent] [no_log_info] [debug]
13 pam_tally2 [--file /path/to/counter] [--user username] [--reset[=n]]
15 [--quiet]
16
18 This module maintains a count of attempted accesses, can reset count on
19 success, can deny access if too many attempts fail.
20 pam_tally2 comes in two parts: pam_tally2.so and pam_tally2. The former
22 is the PAM module and the latter, a stand-alone program. pam_tally2 is
23 an (optional) application which can be used to interrogate and
24 manipulate the counter file. It can display user counts, set individual
25 counts, or clear all counts. Setting artificially high counts may be
26 useful for blocking users without changing their passwords. For
27 example, one might find it useful to clear all counts every midnight
28 from a cron job.
29 Normally, failed attempts to access root will not cause the root
31 account to become blocked, to prevent denial-of-service: if your users
32 aren't given shell accounts and root may only login via su or at the
33 machine console (not telnet/rsh, etc), this is safe.
34
36 GLOBAL OPTIONS
37 This can be used for auth and account module types.
38 onerr=[fail|succeed]
40 If something weird happens (like unable to open the file),
41 return with PAM_SUCCESS if onerr=succeed is given, else with
42 the corresponding PAM error code.
43 file=/path/to/counter
45 File where to keep counts. Default is /var/log/tallylog.
46 audit
48 Will log the user name into the system log if the user is not
49 found.
50 silent
52 Don't print informative messages.
53 no_log_info
55 Don't log informative messages via syslog(3).
56 debug
58 Always log tally count when it is incremented as a debug level
59 message to the system log.
60 AUTH OPTIONS
62 Authentication phase first increments attempted login counter and
63 checks if user should be denied access. If the user is
64 authenticated and the login process continues on call to
65 pam_setcred(3) it resets the attempts counter.
66 deny=n
68 Deny access if tally for this user exceeds n.
69 lock_time=n
71 Always deny for n seconds after failed attempt.
72 unlock_time=n
74 Allow access after n seconds after failed attempt. If this
75 option is used the user will be locked out for the specified
76 amount of time after he exceeded his maximum allowed attempts.
77 Otherwise the account is locked until the lock is removed by a
78 manual intervention of the system administrator.
79 magic_root
81 If the module is invoked by a user with uid=0 the counter is
82 not incremented. The sysadmin should use this for user launched
83 services, like su, otherwise this argument should be omitted.
84 even_deny_root
86 Root account can become unavailable.
87 root_unlock_time=n
89 This option implies even_deny_root option. Allow access after n
90 seconds to root account after failed attempt. If this option is
91 used the root user will be locked out for the specified amount
92 of time after he exceeded his maximum allowed attempts.
93 serialize
95 Serialize access to the tally file using locks. This option
96 might be used only for non-multithreaded services because it
97 depends on the fcntl locking of the tally file. Also it is a
98 good idea to use this option only in such configurations where
99 the time between auth phase and account or setcred phase is not
100 dependent on the authenticating client. Otherwise the
101 authenticating client will be able to prevent simultaneous
102 authentications by the same user by simply artificially
103 prolonging the time the file record lock is held.
104 ACCOUNT OPTIONS
106 Account phase resets attempts counter if the user is not magic
107 root. This phase can be used optionally for services which don't
108 call pam_setcred(3) correctly or if the reset should be done
109 regardless of the failure of the account phase of other modules.
110 magic_root
112 If the module is invoked by a user with uid=0 the counter is
113 not changed. The sysadmin should use this for user launched
114 services, like su, otherwise this argument should be omitted.
115
117 The auth and account module types are provided.
118
120 PAM_AUTH_ERR
121 A invalid option was given, the module was not able to retrieve the
122 user name, no valid counter file was found, or too many failed
123 logins.
124 PAM_SUCCESS
126 Everything was successful.
127 PAM_USER_UNKNOWN
129 User not known.
130
132 pam_tally2 is not compatible with the old pam_tally faillog file
133 format. This is caused by requirement of compatibility of the tallylog
134 file format between 32bit and 64bit architectures on multiarch systems.
135 There is no setuid wrapper for access to the data file such as when the
137 pam_tally2.so module is called from xscreensaver. As this would make it
138 impossible to share PAM configuration with such services the following
139 workaround is used: If the data file cannot be opened because of
140 insufficient permissions (EACCES) the module returns PAM_IGNORE.
141
143 Add the following line to /etc/pam.d/login to lock the account after 4
144 failed logins. Root account will be locked as well. The accounts will
145 be automatically unlocked after 20 minutes. The module does not have to
146 be called in the account phase because the login calls pam_setcred(3)
147 correctly.
148 auth required pam_securetty.so
150 auth required pam_tally2.so deny=4 even_deny_root unlock_time=1200
151 auth required pam_env.so
152 auth required pam_unix.so
153 auth required pam_nologin.so
154 account required pam_unix.so
155 password required pam_unix.so
156 session required pam_limits.so
157 session required pam_unix.so
158 session required pam_lastlog.so nowtmp
159 session optional pam_mail.so standard
160
163 /var/log/tallylog
164 failure count logging file
165
167 pam.conf(5), pam.d(5), pam(8)
168
170 pam_tally2 was written by Tim Baverstock and Tomas Mraz.
171Linux-PAM Manual 05/18/2017 PAM_TALLY2(8)