Windows PowerShell command on Get-command RBAC

Manual Pages for UNIX Operating System command usage for man RBAC

Standards, Environments, and Macros rbac(5)

NAME

rbac, RBAC - role-based access control

DESCRIPTION

The addition of role-based access control (RBAC) to the

Solaris operating environment gives developers the opportun-

ity to deliver fine-grained security in new and modified

applications. RBAC is an alternative to the all-or-nothing

security model of traditional superuser-based systems. With

RBAC, an administrator can assign privileged functions to

specific user accounts (or special accounts called roles). There are two ways to give applications privileges: 1. Administrators can assign special attributes such as setUID to application binaries (executable files). 2. Administrators can assign special attributes such as setUID to applications using execution profiles. Special attribute assignment along with the theory behind

RBAC is discussed in detail in "Role Based Access Control"

chapter of the System Administration Guide: Security Ser-

vices. This chapter describes what authorizations are and how to code for them. Authorizations An authorization is a unique string that represents a user's right to perform some operation or class of operations. Authorization definitions are stored in a database called

auth_attr(4). For programming authorization checks, only the

authorization name is significant.

Some typical values in an auth_attr database are shown

below. solaris.jobs.:::Cron and At Jobs::help=JobHeader.html solaris.jobs.grant:::Delegate Cron & At \ Administration::help=JobsGrant.html solaris.jobs.admin:::Manage All Jobs::help=AuthJobsAdmin.html solaris.jobs.user:::Cron & At User::help=JobsUser.html Authorization name strings ending with the grant suffix are special authorizations that give a user the ability to delegate authorizations with the same prefix and functional area to other users.

SunOS 5.11 Last change: 15 Jul 2003 1

Standards, Environments, and Macros rbac(5) Creating Authorization Checks To check authorizations, use the chkauthattr(3SECDB) library function, which verifies whether or not a user has a given authorization. The synopsis is: int chkauthattr(const char *authname, const char *username); The chkauthattr() function checks the policy.conf(4),

user_attr(4), and prof_attr(4) databases in order for a

match to the given authorization. If you are modifying existing code that tests for root UID, you should find the test in the code and replace it with the chkauthattr() function. A typical root UID check is shown in

the first code segment below. An authorization check replac-

ing it is shown in the second code segment; it uses the solaris.jobs.admin authorization and a variable called

real_login representing the user.

Example 1 Standard root check ruid = getuid(); if ((eflag || lflag || rflag) && argc == 1) { if ((pwp = getpwnam(*argv)) == NULL) crabort(INVALIDUSER); if (ruid != 0) {

if (pwp->pw_uid != ruid)

crabort(NOTROOT); else pp = getuser(ruid); } else pp = *argv++; } else { Example 2 Authorization check ruid = getuid(); if ((pwp = getpwuid(ruid)) == NULL) crabort(INVALIDUSER);

strcpy(real_login, pwp->pw_name);

if ((eflag || lflag || rflag) && argc == 1) { if ((pwp = getpwnam(*argv)) == NULL) crabort(INVALIDUSER);

SunOS 5.11 Last change: 15 Jul 2003 2

Standards, Environments, and Macros rbac(5)

if (!chkauthattr("solaris.jobs.admin", real_login)) {

if (pwp->pw_uid != ruid)

crabort(NOTROOT); else pp = getuser(ruid); } else pp = *argv++; } else { For new applications, find an appropriate location for the test and use chkauthattr() as shown above. Typically the authorization check makes an access decision based on the identity of the calling user to determine if a privileged action (for example, a system call) should be taken on behalf of that user. Applications that perform a test to restrict who can perform

their security-relevant functionality are generally setuid

to root. Programs that were written prior to RBAC and that

are only available to the root user may not have such checks. In most cases, the kernel requires an effective user ID of root to override policy enforcement. Therefore, authorization checking is most useful in programs that are setuid to root. For instance, if you want to write a program that allows authorized users to set the system date, the command must be run with an effective user ID of root. Typically, this means

that the file modes for the file would be -rwsr-xr-x with

root ownership. Use caution, though, when making programs setuid to root. For example, the effective UID should be set to the real UID

as early as possible in the program's initialization func-

tion. The effective UID can then be set back to root after the authorization check is performed and before the system call is made. On return from the system call, the effective UID should be set back to the real UID again to adhere to the principle of least privilege.

Another consideration is that LD_LIBRARY path is ignored for

setuid programs (see SECURITY section in ld.so.1(1)) and that shell scripts must be modified to work properly when the effective and real UIDs are different. For example, the

-p flag in Bourne shell is required to avoid resetting the

effective UID back to the real UID.

SunOS 5.11 Last change: 15 Jul 2003 3

Standards, Environments, and Macros rbac(5) Using an effective UID of root instead of the real UID requires extra care when writing shell scripts. For example, many shell scripts check to see if the user is root before

executing their functionality. With RBAC, these shell

scripts may be running with the effective UID of root and with a real UID of a user or role. Thus, the shell script should check euid instead of uid. For example,

WHO=`id | cut -f1 -d" "`

if [ ! "$WHO" = "uid=0(root)" ]

then

echo "$PROG: ERROR: you must be super-user to run this script."

exit 1 fi should be changed to

WHO=`/usr/xpg4/bin/id -n -u`

if [ ! "$WHO" = "root" ]

then

echo "$PROG: ERROR: you are not authorized to run this script."

exit 1 fi Authorizations can be explicitly checked in shell scripts by checking the output of the auths(1) utility. For example, for auth in `auths | tr , " "` NOTFOUND do

[ "$auth" = "solaris.date" ] && break # authorization found

done

if [ "$auth" != "solaris.date" ]

then

echo >&2 "$PROG: ERROR: you are not authorized to set the date"

exit 1 fi

Manual Pages for UNIX Operating System command usage for man RBAC

NAME

rbac, RBAC - role-based access control

DESCRIPTION

The addition of role-based access control (RBAC) to the

applications. RBAC is an alternative to the all-or-nothing

RBAC, an administrator can assign privileged functions to

RBAC is discussed in detail in "Role Based Access Control"

to root. Programs that were written prior to RBAC and that

executing their functionality. With RBAC, these shell

echo "$PROG: ERROR: you must be super-user to run this script."

echo "$PROG: ERROR: you are not authorized to run this script."

echo >&2 "$PROG: ERROR: you are not authorized to set the date"

SEE ALSO