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Diffstat (limited to 'modules/pam_unix/pam_unix.8')
| -rw-r--r-- | modules/pam_unix/pam_unix.8 | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/modules/pam_unix/pam_unix.8 b/modules/pam_unix/pam_unix.8 new file mode 100644 index 00000000..164843a6 --- /dev/null +++ b/modules/pam_unix/pam_unix.8 @@ -0,0 +1,387 @@ +.\" Title: pam_unix +.\" Author: [see the "AUTHOR" section] +.\" Generator: DocBook XSL Stylesheets v1.74.0 <http://docbook.sf.net/> +.\" Date: 10/27/2010 +.\" Manual: Linux-PAM Manual +.\" Source: Linux-PAM Manual +.\" Language: English +.\" +.TH "PAM_UNIX" "8" "10/27/2010" "Linux-PAM Manual" "Linux\-PAM Manual" +.\" ----------------------------------------------------------------- +.\" * (re)Define some macros +.\" ----------------------------------------------------------------- +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" toupper - uppercase a string (locale-aware) +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de toupper +.tr aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ +\\$* +.tr aabbccddeeffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" SH-xref - format a cross-reference to an SH section +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de SH-xref +.ie n \{\ +.\} +.toupper \\$* +.el \{\ +\\$* +.\} +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" SH - level-one heading that works better for non-TTY output +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de1 SH +.\" put an extra blank line of space above the head in non-TTY output +.if t \{\ +.sp 1 +.\} +.sp \\n[PD]u +.nr an-level 1 +.set-an-margin +.nr an-prevailing-indent \\n[IN] +.fi +.in \\n[an-margin]u +.ti 0 +.HTML-TAG ".NH \\n[an-level]" +.it 1 an-trap +.nr an-no-space-flag 1 +.nr an-break-flag 1 +\." make the size of the head bigger +.ps +3 +.ft B +.ne (2v + 1u) +.ie n \{\ +.\" if n (TTY output), use uppercase +.toupper \\$* +.\} +.el \{\ +.nr an-break-flag 0 +.\" if not n (not TTY), use normal case (not uppercase) +\\$1 +.in \\n[an-margin]u +.ti 0 +.\" if not n (not TTY), put a border/line under subheading +.sp -.6 +\l'\n(.lu' +.\} +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" SS - level-two heading that works better for non-TTY output +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de1 SS +.sp \\n[PD]u +.nr an-level 1 +.set-an-margin +.nr an-prevailing-indent \\n[IN] +.fi +.in \\n[IN]u +.ti \\n[SN]u +.it 1 an-trap +.nr an-no-space-flag 1 +.nr an-break-flag 1 +.ps \\n[PS-SS]u +\." make the size of the head bigger +.ps +2 +.ft B +.ne (2v + 1u) +.if \\n[.$] \&\\$* +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" BB/BE - put background/screen (filled box) around block of text +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de BB +.if t \{\ +.sp -.5 +.br +.in +2n +.ll -2n +.gcolor red +.di BX +.\} +.. +.de EB +.if t \{\ +.if "\\$2"adjust-for-leading-newline" \{\ +.sp -1 +.\} +.br +.di +.in +.ll +.gcolor +.nr BW \\n(.lu-\\n(.i +.nr BH \\n(dn+.5v +.ne \\n(BHu+.5v +.ie "\\$2"adjust-for-leading-newline" \{\ +\M[\\$1]\h'1n'\v'+.5v'\D'P \\n(BWu 0 0 \\n(BHu -\\n(BWu 0 0 -\\n(BHu'\M[] +.\} +.el \{\ +\M[\\$1]\h'1n'\v'-.5v'\D'P \\n(BWu 0 0 \\n(BHu -\\n(BWu 0 0 -\\n(BHu'\M[] +.\} +.in 0 +.sp -.5v +.nf +.BX +.in +.sp .5v +.fi +.\} +.. +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" BM/EM - put colored marker in margin next to block of text +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.de BM +.if t \{\ +.br +.ll -2n +.gcolor red +.di BX +.\} +.. +.de EM +.if t \{\ +.br +.di +.ll +.gcolor +.nr BH \\n(dn +.ne \\n(BHu +\M[\\$1]\D'P -.75n 0 0 \\n(BHu -(\\n[.i]u - \\n(INu - .75n) 0 0 -\\n(BHu'\M[] +.in 0 +.nf +.BX +.in +.fi +.\} +.. +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.SH "Name" +pam_unix \- Module for traditional password authentication +.SH "Synopsis" +.fam C +.HP \w'\fBpam_unix\&.so\fR\ 'u +\fBpam_unix\&.so\fR [\&.\&.\&.] +.fam +.SH "DESCRIPTION" +.PP +This is the standard Unix authentication module\&. It uses standard calls from the system\'s libraries to retrieve and set account information as well as authentication\&. Usually this is obtained from the /etc/passwd and the /etc/shadow file as well if shadow is enabled\&. +.PP +The account component performs the task of establishing the status of the user\'s account and password based on the following +\fIshadow\fR +elements: expire, last_change, max_change, min_change, warn_change\&. In the case of the latter, it may offer advice to the user on changing their password or, through the +\fBPAM_AUTHTOKEN_REQD\fR +return, delay giving service to the user until they have established a new password\&. The entries listed above are documented in the +\fBshadow\fR(5) +manual page\&. Should the user\'s record not contain one or more of these entries, the corresponding +\fIshadow\fR +check is not performed\&. +.PP +The authentication component performs the task of checking the users credentials (password)\&. The default action of this module is to not permit the user access to a service if their official password is blank\&. +.PP +A helper binary, +\fBunix_chkpwd\fR(8), is provided to check the user\'s password when it is stored in a read protected database\&. This binary is very simple and will only check the password of the user invoking it\&. It is called transparently on behalf of the user by the authenticating component of this module\&. In this way it is possible for applications like +\fBxlock\fR(1) +to work without being setuid\-root\&. The module, by default, will temporarily turn off SIGCHLD handling for the duration of execution of the helper binary\&. This is generally the right thing to do, as many applications are not prepared to handle this signal from a child they didn\'t know was +\fBfork()\fRd\&. The +\fBnoreap\fR +module argument can be used to suppress this temporary shielding and may be needed for use with certain applications\&. +.PP +The password component of this module performs the task of updating the user\'s password\&. +.PP +The session component of this module logs when a user logins or leave the system\&. +.PP +Remaining arguments, supported by others functions of this module, are silently ignored\&. Other arguments are logged as errors through +\fBsyslog\fR(3)\&. +.SH "OPTIONS" +.PP +\fBdebug\fR +.RS 4 +Turns on debugging via +\fBsyslog\fR(3)\&. +.RE +.PP +\fBaudit\fR +.RS 4 +A little more extreme than debug\&. +.RE +.PP +\fBnullok\fR +.RS 4 +The default action of this module is to not permit the user access to a service if their official password is blank\&. The +\fBnullok\fR +argument overrides this default\&. +.RE +.PP +\fBtry_first_pass\fR +.RS 4 +Before prompting the user for their password, the module first tries the previous stacked module\'s password in case that satisfies this module as well\&. +.RE +.PP +\fBuse_first_pass\fR +.RS 4 +The argument +\fBuse_first_pass\fR +forces the module to use a previous stacked modules password and will never prompt the user \- if no password is available or the password is not appropriate, the user will be denied access\&. +.RE +.PP +\fBnodelay\fR +.RS 4 +This argument can be used to discourage the authentication component from requesting a delay should the authentication as a whole fail\&. The default action is for the module to request a delay\-on\-failure of the order of two second\&. +.RE +.PP +\fBuse_authtok\fR +.RS 4 +When password changing enforce the module to set the new password to the one provided by a previously stacked +\fBpassword\fR +module (this is used in the example of the stacking of the +\fBpam_cracklib\fR +module documented below)\&. +.RE +.PP +\fBnot_set_pass\fR +.RS 4 +This argument is used to inform the module that it is not to pay attention to/make available the old or new passwords from/to other (stacked) password modules\&. +.RE +.PP +\fBnis\fR +.RS 4 +NIS RPC is used for setting new passwords\&. +.RE +.PP +\fBremember=\fR\fB\fIn\fR\fR +.RS 4 +The last +\fIn\fR +passwords for each user are saved in +\FC/etc/security/opasswd\F[] +in order to force password change history and keep the user from alternating between the same password too frequently\&. +.RE +.PP +\fBshadow\fR +.RS 4 +Try to maintain a shadow based system\&. +.RE +.PP +\fBmd5\fR +.RS 4 +When a user changes their password next, encrypt it with the MD5 algorithm\&. +.RE +.PP +\fBbigcrypt\fR +.RS 4 +When a user changes their password next, encrypt it with the DEC C2 algorithm\&. +.RE +.PP +\fBsha256\fR +.RS 4 +When a user changes their password next, encrypt it with the SHA256 algorithm\&. If the SHA256 algorithm is not known to the +\fBcrypt\fR(3) +function, fall back to MD5\&. +.RE +.PP +\fBsha512\fR +.RS 4 +When a user changes their password next, encrypt it with the SHA512 algorithm\&. If the SHA512 algorithm is not known to the +\fBcrypt\fR(3) +function, fall back to MD5\&. +.RE +.PP +\fBblowfish\fR +.RS 4 +When a user changes their password next, encrypt it with the blowfish algorithm\&. If the blowfish algorithm is not known to the +\fBcrypt\fR(3) +function, fall back to MD5\&. +.RE +.PP +\fBrounds=\fR\fB\fIn\fR\fR +.RS 4 +Set the optional number of rounds of the SHA256, SHA512 and blowfish password hashing algorithms to +\fIn\fR\&. +.RE +.PP +\fBbroken_shadow\fR +.RS 4 +Ignore errors reading shadow information for users in the account management module\&. +.RE +.PP +\fBminlen=\fR\fB\fIn\fR\fR +.RS 4 +Set a minimum password length of +\fIn\fR +characters\&. The max\&. for DES crypt based passwords are 8 characters\&. +.RE +.PP +Invalid arguments are logged with +\fBsyslog\fR(3)\&. +.SH "MODULE TYPES PROVIDED" +.PP +All module types (\fBaccount\fR, +\fBauth\fR, +\fBpassword\fR +and +\fBsession\fR) are provided\&. +.SH "RETURN VALUES" +.PP +PAM_IGNORE +.RS 4 +Ignore this module\&. +.RE +.SH "EXAMPLES" +.PP +An example usage for +\FC/etc/pam\&.d/login\F[] +would be: +.sp +.if n \{\ +.RS 4 +.\} +.fam C +.ps -1 +.nf +.if t \{\ +.sp -1 +.\} +.BB lightgray adjust-for-leading-newline +.sp -1 + +# Authenticate the user +auth required pam_unix\&.so +# Ensure users account and password are still active +account required pam_unix\&.so +# Change the users password, but at first check the strength +# with pam_cracklib(8) +password required pam_cracklib\&.so retry=3 minlen=6 difok=3 +password required pam_unix\&.so use_authtok nullok md5 +session required pam_unix\&.so + +.EB lightgray adjust-for-leading-newline +.if t \{\ +.sp 1 +.\} +.fi +.fam +.ps +1 +.if n \{\ +.RE +.\} +.sp +.SH "SEE ALSO" +.PP + +\fBpam.conf\fR(5), +\fBpam.d\fR(5), +\fBpam\fR(8) +.SH "AUTHOR" +.PP +pam_unix was written by various people\&. |