Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

pkcheck(1) [suse man page]

PKCHECK(1)							      pkcheck								PKCHECK(1)

NAME
pkcheck - Check whether a process is authorized SYNOPSIS
pkcheck [--version] [--help] pkcheck --action-id action {--process { pid | pid,pid-start-time } | --system-bus-name busname} [--allow-user-interaction] [--detail key value...] DESCRIPTION
pkcheck is used to check whether a process, specified by either --process or --system-bus-name, is authorized for action. The --detail option can be used zero or more times to pass details about action. If --allow-user-interaction is passed, pkcheck blocks while waiting for authentication. This command is a simple wrapper around the PolicyKit D-Bus interface; see the D-Bus interface documentation for details. RETURN VALUE
If the specified process is authorized, pkcheck exits with a return value of 0. If the authorization result contains any details, these are printed on standard output as key/value pairs using environment style reporting, e.g. first the key followed by a an equal sign, then the value followed by a newline. KEY1=VALUE1 KEY2=VALUE2 KEY3=VALUE3 ... Octects that are not in [a-zA-Z0-9_] are escaped using octal codes prefixed with . For example, the UTF-8 string fol, will be printed as f303270l54344275240345245275. If the specificied process is not authorized, pkcheck exits with a return value of 1 and a diagnostic message is printed on standard error. Details are printed on standard output. If the specificied process is not authorized because no suitable authentication agent is available or if the --allow-user-interaction wasn't passed, pkcheck exits with a return value of 2 and a diagnostic message is printed on standard error. Details are printed on standard output. If an error occured while checking for authorization, pkcheck exits with a return value of 127 with a diagnostic message printed on standard error. If one or more of the options passed are malformed, pkcheck exits with a return value of 126. If stdin is a tty, then this manual page is also shown. NOTES
Since process identifiers can be recycled, the caller should always use pid,pid-start-time to specify the process to check for authorization when using the --process option. The value of pid-start-time can be determined by consulting e.g. the proc(5) file system depending on the operating system. If only pid is passed to the --process option, then pkcheck will look up the start time itself but note that this may be racy. AUTHOR
Written by David Zeuthen davidz@redhat.com with a lot of help from many others. BUGS
Please send bug reports to either the distribution or the polkit-devel mailing list, see the link http://lists.freedesktop.org/mailman/listinfo/polkit-devel on how to subscribe. SEE ALSO
polkit(8), pkaction(1), pkexec(1) polkit May 2009 PKCHECK(1)

Check Out this Related Man Page

PKEXEC(1)							      pkexec								 PKEXEC(1)

NAME
pkexec - Execute a command as another user SYNOPSIS
pkexec [--version] [--disable-internal-agent] [--help] pkexec [--user username] PROGRAM [ARGUMENTS...] DESCRIPTION
pkexec allows an authorized user to execute PROGRAM as another user. If username is not specified, then the program will be executed as the administrative super user, root. RETURN VALUE
Upon successful completion, the return value is the return value of PROGRAM. If the calling process is not authorized or an authorization could not be obtained through authentication or an error occured, pkexec exits with a return value of 127. If the authorization could not be obtained because the user dismissed the authentication dialog, pkexec exits with a return value of 126. AUTHENTICATION AGENT
pkexec, like any other PolicyKit application, will use the authentication agent registered for the calling process. However, if no authentication agent is available, then pkexec will register its own textual authentication agent. This behavior can be turned off by passing the --disable-internal-agent option. SECURITY NOTES
Executing a program as another user is a privileged operation. By default the required authorization (See the section called "REQUIRED AUTHORIZATIONS") requires administrator authentication. In addition, the authentication dialog presented to the user will display the full path to the program to be executed so the user is aware of what will happen: [IMAGE][1] +----------------------------------------------------------+ | Authenticate [X] | +----------------------------------------------------------+ | | | [Icon] Authentication is needed to run `/bin/bash' | | as the super user | | | | An application is attempting to perform an | | action that requires privileges. Authentication | | as the super user is required to perform this | | action. | | | | Password for root: [_________________________] | | | | [V] Details: | | Command: /bin/bash | | Run As: Super User (root) | | Action: org.freedesktop.policykit.exec | | Vendor: The PolicyKit Project | | | | [Cancel] [Authenticate] | +----------------------------------------------------------+ The environment that PROGRAM will run it, will be set to a minimal known and safe environment in order to avoid injecting code through LD_LIBRARY_PATH or similar mechanisms. In addition the PKEXEC_UID environment variable is set to the user id of the process invoking pkexec. As a result, pkexec will not allow you to run X11 applications as another user since the $DISPLAY and $XAUTHORITY environment variables are not set. These two variables will be retained if the org.freedesktop.policykit.exec.allow_gui annotation on an action is set to a nonempty value; this is discouraged, though, and should only be used for legacy programs. REQUIRED AUTHORIZATIONS
By default, the org.freedesktop.policykit.exec authorization is required unless an action definition file is present for the program in question. To require another authorization, it can be specified using the org.freedesktop.policykit.exec.path annotation on an action (See the section called "EXAMPLE" for details). EXAMPLE
To specify what kind of authorization is needed to execute the program /usr/bin/pk-example-frobnicate as another user, simply write an action definition file like this <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE policyconfig PUBLIC "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN" "http://www.freedesktop.org/standards/PolicyKit/1/policyconfig.dtd"> <policyconfig> <vendor>Examples for the PolicyKit Project</vendor> <vendor_url>http://hal.freedesktop.org/docs/PolicyKit/</vendor_url> <action id="org.freedesktop.policykit.example.pkexec.run-frobnicate"> <description>Run the PolicyKit example program Frobnicate</description> <description xml:lang="da">Kor PolicyKit eksemplet Frobnicate</description> <message>Authentication is required to run the PolicyKit example program Frobnicate (user=$(user), program=$(program), command_line=$(command_line))</message> <message xml:lang="da">Autorisering er pakraevet for at afvikle PolicyKit eksemplet Frobnicate (user=$(user), program=$(program), command_line=$(command_line))</message> <icon_name>audio-x-generic</icon_name> <defaults> <allow_any>no</allow_any> <allow_inactive>no</allow_inactive> <allow_active>auth_self_keep</allow_active> </defaults> <annotate key="org.freedesktop.policykit.exec.path">/usr/bin/pk-example-frobnicate</annotate> </action> </policyconfig> and drop it in the /usr/share/polkit-1/actions directory under a suitable name (e.g. matching the namespace of the action). Note that in addition to specifying the program, the authentication message, description, icon and defaults can be specified. Note that occurences of the strings $(user), $(program) and $(command_line) in the message will be replaced with respectively the user (of the form "Real Name (username)" or just "username" if there is no real name for the username), the binary to execute (a fully-qualified path, e.g. "/usr/bin/pk-example-frobnicate") and the command-line, e.g. "pk-example-frobnicate foo bar". For example, for the action defined above, the following authentication dialog will be shown: [IMAGE][2] +----------------------------------------------------------+ | Authenticate [X] | +----------------------------------------------------------+ | | | [Icon] Authentication is required to run the PolicyKit | | example program Frobnicate | | | | An application is attempting to perform an | | action that requires privileges. Authentication | | is required to perform this action. | | | | Password: [__________________________________] | | | | [V] Details: | | Command: /usr/bin/pk-example-frobnicate | | Run As: Super User (root) | | Action: org.fd.pk.example.pkexec.run-frobnicate | | Vendor: Examples for the PolicyKit Project | | | | [Cancel] [Authenticate] | +----------------------------------------------------------+ If the user is using the da_DK locale, the dialog looks like this: [IMAGE][3] +----------------------------------------------------------+ | Autorisering [X] | +----------------------------------------------------------+ | | | [Icon] Autorisering er pakraevet for at afvikle | | PolicyKit eksemplet Frobnicate | | | | Et program forsoger at udfore en handling der | | kraever privilegier. Autorisering er pakraevet. | | | | Kodeord: [___________________________________] | | | | [V] Detaljer: | | Bruger: Super User (root) | | Program: /usr/bin/pk-example-frobnicate | | Handling: org.fd.pk.example.pkexec.run-frobnicate | | Vendor: Examples for the PolicyKit Project | | | | [Annuller] [Autorisering] | +----------------------------------------------------------+ Note that pkexec does no validation of the ARGUMENTS passed to PROGRAM. In the normal case (where administrator authentication is required every time pkexec is used), this is not a problem since if the user is an administrator he might as well just run pkexec bash to get root. However, if an action is used for which the user can retain authorization (or if the user is implicitly authorized), such as with pk-example-frobnicate above, this could be a security hole. Therefore, as a rule of thumb, programs for which the default required authorization is changed, should never implicitly trust user input (e.g. like any other well-written suid program). AUTHOR
Written by David Zeuthen davidz@redhat.com with a lot of help from many others. BUGS
Please send bug reports to either the distribution or the polkit-devel mailing list, see the link http://lists.freedesktop.org/mailman/listinfo/polkit-devel on how to subscribe. SEE ALSO
polkit(8), pkaction(1), pkcheck(1), pkttyagent(1) NOTES
1. /usr/share/gtk-doc/html/polkit-1/pkexec-bash.png 2. /usr/share/gtk-doc/html/polkit-1/pkexec-frobnicate.png 3. /usr/share/gtk-doc/html/polkit-1/pkexec-frobnicate-da.png polkit May 2009 PKEXEC(1)
Man Page

Featured Tech Videos