bionic (8) userhelper.8.gz

Provided by: usermode_1.109-1build1_amd64 bug

NAME

       userhelper - A helper interface to PAM.

SYNOPSIS

       userhelper    [ -t ]   [ -w prog args ]   [ -c ]   [ -f full-name ]   [ -o office ]   [ -p office-phone ]
       [ -h home-phone ] [ -s shell ] [ username ]

DESCRIPTION

       NOTE this program is NOT intended to be run interactively.  If you want to change this information on the
       command line use passwd(1), chfn(1), or chsh(1).

       This  program  provides a basic interface to change a user's password, gecos information, and shell.  The
       main difference between this program and its traditional equivalents  is  that  prompts  are  written  to
       standard out to make it easy for a GUI wrapper to interface to it as a child process.

       The output is in the form of:

       <number> <string>

       Where  the  number  is  the type of prompt returned from libpam, and the string is the prompt to give the
       user.

       The prompt numbers are as follows:

       1      Prompt with visible input.

       2      Prompt with invisible input.

       3      Suggested answer for the current prompt.

       4      Informational message.

       5      Error message.

       6      Count of messages sent in this block so far.

       7      The name of the service being used.

       8      Whether or not the command will be executed as the user if authentication fails.

       9      The name of the user being authenticated.

OPTIONS

       -t     Use text mode authentication instead of the numbered message types just described; only used  with
              -w.

       -w     Specify  a  program  name to be run and arguments to be passed to it.  userhelper will look in the
              file /etc/security/console.apps/programname for the name of a user to authenticate,  the  path  of
              the  binary  to  be  run,  and  other  settings  described below.  userhelper will then attempt to
              authenticate  the  user  using  PAM,  specifying  programname  as  the  PAM  service   name.    If
              authentication  succeeds,  the binary will be run with superuser privileges.  If the configuration
              file specifies that PAM session management should be performed, userhelper will also  open  a  PAM
              session  before  starting  the  program,  and  close  the session when the program terminates.  If
              authentication fails, userhelper can be configured run the  program  with  the  user's  privileges
              instead.

       -c     Change  the  current  user's password.  Note that this option cannot be used with any of the other
              options.  This is due to the limitation in the interface to libpam.

       -f     Specify a new Full Name.

       -o     Specify a new Office.

       -p     Specify a new Office Phone.

       -h     Specify a new Home Phone.

       -s     Specify a new shell.

WRAPPER CONFIGURATION

       The wrapper configuration file used with -w contains variable assignments and file inclusions.

       A file inclusion line has the following form:
              . path
       (that is a dot and a space, followed by path).  If path is relative, it is interpreted  relative  to  the
       directory  containing  the current file.  The file inclusion line is interpreted by inserting contents of
       path to the current file.  Nested file inclusions are  possible,  recursive  file  inclusion  results  in
       undefined behavior.

       A variable assignment line has the following form:
              name=value
       No  additional  white  space is allowed.  If value is surrounded by a matching pair of " or ' quotes, the
       quotes are removed; otherwise, the \ characters are removed, except that \\ is replaced by a single \.

       The following variables are recognized:

       USER   The name of the user userhelper should attempt to authenticate the invoking  user  as.   Typically
              this  is  root.   The  special  value <user> (which is also the default) indicates that userhelper
              should authenticate the invoking user.

              The special value <none> indicates that access should be denied; when  used  in  conjunction  with
              UGROUPS,  members  of  the  given groups can authenticate but all others are given an Insufficient
              Rights message.

       UGROUPS
              A comma-separated list of groups whose members will be authenticated as if USER were  set  to  the
              special  value  <user>.  If  the  invoking  user  is not a member of one of these groups, the name
              defined in USER will be used as normal. For example, setting UGROUPS to wheel  and  USER  to  root
              allows  members  of  wheel (traditionally used for administrative privileges) to authenticate with
              their own credentials and requires other users to provide the root password.

       PROGRAM
              The name of the binary to execute if authentication succeeds.  This should always be specified  as
              an  absolute  path.  If not specified, userhelper will attempt to run /sbin/programname first, and
              failing that, it will attempt to run /usr/sbin/programname.

       SESSION
              Specifies whether or not userhelper  should  perform  PAM  session  management  when  running  the
              program.   Typically this is needed if the PAM configuration uses a module such as pam_xauth.so to
              forward X11 authentication tokens for use by the program.  Valid values are yes and no,  with  the
              default being no.

       KEEP_ENV_VARS
              A comma-separated list of names of environment variables that should be kept in the environment of
              the wrapped program.  The environment is cleared by default and only a few selected variables  are
              kept in the environment if they do not contain any potentially dangerous substrings.

       RETRY  Specifies  the  number  of times userhelper should attempt to authenticate the user if the initial
              attempt fails.  The default value is 2, which causes userhelper to  attempt  to  authenticate  the
              user a total of 3 times.

       FALLBACK
              Specifies whether or not the specified binary should be run with the invoking user's privileges if
              authentication fails.  This option is  useful  for  running  applications  which  gain  additional
              abilities when run with superuser privileges, but which are still useful when run without them.

       NOXOPTION
              The  name  of an option which, if passed to userhelper as an argument for the program it will run,
              will cause userhelper to behave as if the -t flag had been passed to it.

       GUI    Specifies whether or not userhelper should use consolehelper to  present  graphical  dialog  boxes
              when  prompting the user for information.  This is the inverse of the -t option.  Valid values are
              yes and no, with the default being yes.

       BANNER Specifies specific text which userhelper should present to the user when  userhelper  prompts  for
              information.  The default is a generic message based on the PAM service name.

       BANNER_DOMAIN
              Specifies  the  text  domain  in  which  translations  of  the banner are stored.  This setting is
              deprecated in favor of the DOMAIN setting.

       DOMAIN Specifies the text domain in which translations  of  strings  are  stored.   If  this  setting  is
              specified, it overrides any setting for BANNER_DOMAIN which may also be set.

       STARTUP_NOTIFICATION_NAME
              Specifies the startup notification name used for startup notification.

       STARTUP_NOTIFICATION_DESCRIPTION
              Specifies the startup notification name used for startup notification.

       STARTUP_NOTIFICATION_WORKSPACE
              Specifies the startup notification workspace used for startup notification.

       STARTUP_NOTIFICATION_WMCLASS
              Specifies the startup notification binary wmclass used for startup notification.

       STARTUP_NOTIFICATION_BINARY_NAME
              Specifies the startup notification binary name used for startup notification.

       STARTUP_NOTIFICATION_ICON_NAME
              Specifies the startup notification icon name used for startup notification.

EXIT STATUS

       A non-zero exit status indicates an error occurred.  Those errors are:

       1      The authentication passwords was incorrect.

       2      One  or more of the GECOS fields is invalid.  This occurs when there is a colon supplied in one of
              the fields.

       3      Password resetting error.

       4      Some system files are locked.

       5      User unknown.

       6      Insufficient rights.

       7      Invalid call to this program.

       8      The shell provided is not valid (i.e., does not exist in /etc/shells).

       9      Ran out of memory.

       10     Could not find the program.

       11     exec failed even though program exists.

       12     the user canceled the operation.

       255    Unknown error.

FILES

       /etc/passwd              The gecos and shell information is stored in this file.

       /etc/shells              This file is checked to see if the new shell supplied is valid.

       /etc/security/console.apps/prog
                                This file contains the  values  which  will  be  used  for  the  variables  when
                                userhelper is used with the -w flag.

       /etc/pam.d/prog          This  file  contains the PAM configuration used when userhelper is used with the
                                -w flag.

SEE ALSO

       userpasswd(1), userinfo(1), consolehelper(8), chfn(1), chsh(1), passwd(5)

AUTHOR

       Otto Hammersmith <otto@redhat.com>
       Michael K. Johnson <johnsonm@redhat.com>