Controlling execution of Java JAR files with SELinux RBAC

[Bill D]

Greetings:

I have been trying to figure out how to control the execution of Java 
JAR files with SELinux RBAC.

I have two Linux users named joe and mary and two Java JAR files named 
jack.jar and mary.jar.

Here is how jack executes jack.jar: java -jar jack.jar

Here is how mary executes mary.jar: java -jar mary.jar

I would like SELinux RBAC to prevent jack from executing mary.jar and 
prevent mary from executing jack.jar.

How to configure SELinux RBAC to make that happen?

I have tried various approaches without success.  I have also tried the 
steps in http://forums.fedoraforum.org/archive/index.php/t-222938.html 
without success.

I would greatly appreciate any hints.

Regards,

Bill

[Manuel Wolfshant]

On 24 May 2017 02:51:11 EEST, Bill D <littus(a)icloud.com&gt; wrote:
> Greetings:
>
> I have been trying to figure out how to control the execution of Java 
> JAR files with SELinux RBAC.
>
> I have two Linux users named joe and mary and two Java JAR files named 
> jack.jar and mary.jar.
>
> Here is how jack executes jack.jar: java -jar jack.jar
>
> Here is how mary executes mary.jar: java -jar mary.jar
>
> I would like SELinux RBAC to prevent jack from executing mary.jar and 
> prevent mary from executing jack.jar.
>  
Leaving a bit aside the original question (to which I want to learn the answer as
well), may I ask why isn't something like :
  chown jack jack.jar
  chown mary mary.jar
  chmod 700 jack.jar
  chmod 700 mary.jar
suitable for your use case ?

[Bill D]

On 05/23/2017 05:00 PM, Manuel Wolfshant wrote:
>  On 24 May 2017 02:51:11 EEST, Bill D <littus(a)icloud.com&gt;
> wrote:
> > Greetings:
> >
> > I have been trying to figure out how to control the execution of Java
> > JAR files with SELinux RBAC.
> >
> > I have two Linux users named joe and mary and two Java JAR files named
> > jack.jar and mary.jar.
> >
> > Here is how jack executes jack.jar: java -jar jack.jar
> >
> > Here is how mary executes mary.jar: java -jar mary.jar
> >
> > I would like SELinux RBAC to prevent jack from executing mary.jar and
> > prevent mary from executing jack.jar.
> >
>  Leaving a bit aside the original question (to which I want to learn 
>  the answer as well), may I ask why isn't something like :
>     chown jack jack.jar
>     chown mary mary.jar
>     chmod 700 jack.jar
>     chmod 700 mary.jar
>  suitable for your use case ? 
Indeed, I am aware of this approach.  However, that scheme is the DAC 
(discretionary access control) solution which is not ideal for my case.  
I am more interested in the MAC (mandatory access control) solution 
(thus SELinux RBAC).  Thanks!  -Bill

>  _______________________________________________
>  selinux mailing list -- selinux(a)lists.fedoraproject.org
>  To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org

[Philip Seeley]

Hi Bill,

Have you thought about using categories?

https://www.centos.org/docs/5/html/Deployment_Guide-en-US/sec-mcs-getstar...

Cheers

Phil



From:	Bill D <littus(a)icloud.com&gt;
To:	selinux(a)lists.fedoraproject.org
Cc:	littus(a)icloud.com
Date:	24/05/2017 09:52
Subject:	Controlling execution of Java JAR files with SELinux RBAC



Greetings:

I have been trying to figure out how to control the execution of Java
JAR files with SELinux RBAC.

I have two Linux users named joe and mary and two Java JAR files named
jack.jar and mary.jar.

Here is how jack executes jack.jar: java -jar jack.jar

Here is how mary executes mary.jar: java -jar mary.jar

I would like SELinux RBAC to prevent jack from executing mary.jar and
prevent mary from executing jack.jar.

How to configure SELinux RBAC to make that happen?

I have tried various approaches without success.  I have also tried the
steps in http://forums.fedoraforum.org/archive/index.php/t-222938.html
without success.

I would greatly appreciate any hints.

Regards,

Bill


_______________________________________________
selinux mailing list -- selinux(a)lists.fedoraproject.org
To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org

[Bill Durant]

Hello Phil:

Thank you for the suggestion.  I have tried the steps from the URL that 
you provided without success.

I get an error when I try to assign Linux user mary to an SELinux login 
as follows:

# cat /etc/redhat-release
CentOS release 6.9 (Final)

;;; Add "s0:c0=NetworkAdministrator" and "s0:c1=Operator" to 
/etc/selinux/targeted/setrans.conf

# cat /etc/selinux/targeted/setrans.conf
#
# Multi-Category Security translation table for SELinux
#
# Uncomment the following to disable translation libary
# disable=1
#
# Objects can be categorized with 0-1023 categories defined by the admin.
# Objects can be in more than one category at a time.
# Categories are stored in the system as c0-c1023.  Users can use this
# table to translate the categories into a more meaningful output.
# Examples:
# s0:c0=CompanyConfidential
# s0:c1=PatientRecord
# s0:c2=Unclassified
# s0:c3=TopSecret
# s0:c1,c3=CompanyConfidentialRedHat
s0:c0=NetworkAdministrator
s0:c1=Operator
s0=SystemLow
s0-s0:c0.c1023=SystemLow-SystemHigh
s0:c0.c1023=SystemHigh

# service mcstrans start

# chcat -L
s0:c0                          NetworkAdministrator
s0:c1                          Operator
s0                             SystemLow
s0-s0:c0.c1023                 SystemLow-SystemHigh
s0:c0.c1023                    SystemHigh


# useradd mary
# passwd mary
Changing password for user mary.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# semanage login -a mary

# chcat -l -- +NetworkAdministrator mary
libsemanage.validate_handler: MLS range s0-s0:c0 for Unix user mary 
exceeds allowed range s0 for SELinux user user_u (No such file or 
directory).
libsemanage.validate_handler: seuser mapping [mary -> (user_u, 
s0-s0:c0)] is invalid (No such file or directory).
libsemanage.dbase_llist_iterate: could not iterate over records (No such 
file or directory).
/usr/sbin/semanage: Could not commit semanage transaction

I would appreciate any hints on how to resolve that error.

Thanks!

Bill


On 05/23/2017 05:49 PM, Philip Seeley wrote:
>  Hi Bill,
>
>  Have you thought aboutusing categories?
>
>  https://www.centos.org/docs/5/html/Deployment_Guide-en-US/sec-mcs-getstar...
>
>  Cheers
>
>  Phil
>
>  Inactive hide details for Bill D ---24/05/2017 09:52:00---Greetings: I 
>  have been trying to figure out how to control the executBill D 
>  ---24/05/2017 09:52:00---Greetings: I have been trying to figure out 
>  how to control the execution of Java
>
>  From: Bill D <littus(a)icloud.com&gt;
>  To: selinux(a)lists.fedoraproject.org
>  Cc: littus(a)icloud.com
>  Date: 24/05/2017 09:52
>  Subject: Controlling execution of Java JAR files with SELinux RBAC
>
>  ------------------------------------------------------------------------
>
>
>
>  Greetings:
>
>  I have been trying to figure out how to control the execution of Java
>  JAR files with SELinux RBAC.
>
>  I have two Linux users named joe and mary and two Java JAR files named
>  jack.jar and mary.jar.
>
>  Here is how jack executes jack.jar: java -jar jack.jar
>
>  Here is how mary executes mary.jar: java -jar mary.jar
>
>  I would like SELinux RBAC to prevent jack from executing mary.jar and
>  prevent mary from executing jack.jar.
>
>  How to configure SELinux RBAC to make that happen?
>
>  I have tried various approaches without success.  I have also tried the
>  steps in http://forums.fedoraforum.org/archive/index.php/t-222938.html
>  without success.
>
>  I would greatly appreciate any hints.
>
>  Regards,
>
>  Bill
>
>
>  _______________________________________________
>  selinux mailing list -- selinux(a)lists.fedoraproject.org
>  To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org
>
>
>
>
>
>  _______________________________________________
>  selinux mailing list -- selinux(a)lists.fedoraproject.org
>  To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org

[Philip Seeley]

Hi Bill,

This is probably because the default RHEL6 configuration does not include
any categories in the user_u SELinux user's range:

# semanage user -l

                Labeling   MLS/       MLS/
SELinux User    Prefix     MCS Level  MCS Range
SELinux Roles

guest_u         user       s0         s0
guest_r
root            user       s0         s0-s0:c0.c1023
staff_r sysadm_r system_r unconfined_r
staff_u         user       s0         s0-s0:c0.c1023
staff_r sysadm_r system_r unconfined_r
sysadm_u        user       s0         s0-s0:c0.c1023
sysadm_r
system_u        user       s0         s0-s0:c0.c1023
system_r unconfined_r
unconfined_u    user       s0         s0-s0:c0.c1023
system_r unconfined_r
user_u          user       s0         s0                             user_r

You probably have to extend the user definition to include the categories
you're using. As an example, this gives all categories:

# semanage user -m -r s0:c0.c1023 user_u

# semanage user -l

                Labeling   MLS/       MLS/
SELinux User    Prefix     MCS Level  MCS Range
SELinux Roles

guest_u         user       s0         s0
guest_r
root            user       s0         s0-s0:c0.c1023
staff_r sysadm_r system_r unconfined_r
staff_u         user       s0         s0-s0:c0.c1023
staff_r sysadm_r system_r unconfined_r
sysadm_u        user       s0         s0-s0:c0.c1023
sysadm_r
system_u        user       s0         s0-s0:c0.c1023
system_r unconfined_r
unconfined_u    user       s0         s0-s0:c0.c1023
system_r unconfined_r
user_u          user       s0         s0:c0.c1023                    user_r

Hope that helps.

Phil




From:	Bill Durant <littus(a)icloud.com&gt;
To:	Philip Seeley <pseeley(a)au1.ibm.com&gt;
Cc:	littus(a)icloud.com, selinux(a)lists.fedoraproject.org
Date:	24/05/2017 12:34
Subject:	Re: Controlling execution of Java JAR files with SELinux RBAC



Hello Phil:


Thank you for the suggestion.  I have tried the steps from the URL that you
provided without success.


I get an error when I try to assign Linux user mary to an SELinux login as
follows:


# cat /etc/redhat-release
CentOS release 6.9 (Final)

;;; Add "s0:c0=NetworkAdministrator" and "s0:c1=Operator"
to /etc/selinux/targeted/setrans.conf

# cat /etc/selinux/targeted/setrans.conf
#
# Multi-Category Security translation table for SELinux
#
# Uncomment the following to disable translation libary
# disable=1
#
# Objects can be categorized with 0-1023 categories defined by the admin.
# Objects can be in more than one category at a time.
# Categories are stored in the system as c0-c1023.  Users can use this
# table to translate the categories into a more meaningful output.
# Examples:
# s0:c0=CompanyConfidential
# s0:c1=PatientRecord
# s0:c2=Unclassified
# s0:c3=TopSecret
# s0:c1,c3=CompanyConfidentialRedHat
s0:c0=NetworkAdministrator
s0:c1=Operator
s0=SystemLow
s0-s0:c0.c1023=SystemLow-SystemHigh
s0:c0.c1023=SystemHigh

# service mcstrans start

# chcat -L
s0:c0                          NetworkAdministrator
s0:c1                          Operator
s0                             SystemLow
s0-s0:c0.c1023                 SystemLow-SystemHigh
s0:c0.c1023                    SystemHigh


# useradd mary
# passwd mary
Changing password for user mary.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# semanage login -a mary

# chcat -l -- +NetworkAdministrator mary
libsemanage.validate_handler: MLS range s0-s0:c0 for Unix user mary exceeds
allowed range s0 for SELinux user user_u (No such file or directory).
libsemanage.validate_handler: seuser mapping [mary -> (user_u, s0-s0:c0)]
is invalid (No such file or directory).
libsemanage.dbase_llist_iterate: could not iterate over records (No such
file or directory).
/usr/sbin/semanage: Could not commit semanage transaction


I would appreciate any hints on how to resolve that error.


Thanks!


Bill



On 05/23/2017 05:49 PM, Philip Seeley wrote:


      Hi Bill,

      Have you thought about using categories?

      https://www.centos.org/docs/5/html/Deployment_Guide-en-US/sec-mcs-getstar...


      Cheers

      Phil

      Inactive
          hide details for Bill D ---24/05/2017
      09:52:00---Greetings: I
          have been trying to figure out how
      to control the executBill D ---24/05/2017 09:52:00---Greetings: I
      have been trying to figure out how to control the execution of Java

      From: Bill D <littus(a)icloud.com&gt;
      To: selinux(a)lists.fedoraproject.org
      Cc: littus(a)icloud.com
      Date: 24/05/2017 09:52
      Subject: Controlling execution of Java JAR files with SELinux RBAC





      Greetings:

      I have been trying to figure out how to control the execution of Java

      JAR files with SELinux RBAC.

      I have two Linux users named joe and mary and two Java JAR files
      named
      jack.jar and mary.jar.

      Here is how jack executes jack.jar: java -jar jack.jar

      Here is how mary executes mary.jar: java -jar mary.jar

      I would like SELinux RBAC to prevent jack from executing mary.jar and

      prevent mary from executing jack.jar.

      How to configure SELinux RBAC to make that happen?

      I have tried various approaches without success.  I have also tried
      the
      steps in
      http://forums.fedoraforum.org/archive/index.php/t-222938.html
      without success.

      I would greatly appreciate any hints.

      Regards,

      Bill


      _______________________________________________
      selinux mailing list -- selinux(a)lists.fedoraproject.org
      To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org





      _______________________________________________
      selinux mailing list -- selinux(a)lists.fedoraproject.org
      To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org

[Bill D]

Hello Phil,

I have tried your suggestion of extending the user_u definition without 
success:

# semanage user -l

                 Labeling   MLS/ MLS/
SELinux User    Prefix     MCS Level  MCS Range                      
SELinux Roles

git_shell_u     user       SystemLow SystemLow                      
git_shell_r
guest_u         user       SystemLow SystemLow                      guest_r
root            user       SystemLow SystemLow-SystemHigh           
staff_r sysadm_r system_r unconfined_r
staff_u         user       SystemLow SystemLow-SystemHigh           
staff_r sysadm_r system_r unconfined_r
sysadm_u        user       SystemLow SystemLow-SystemHigh           sysadm_r
system_u        user       SystemLow SystemLow-SystemHigh           
system_r unconfined_r
unconfined_u    user       SystemLow SystemLow-SystemHigh           
system_r unconfined_r
user_u          user       SystemLow SystemLow                      user_r
xguest_u        user       SystemLow SystemLow                      xguest_r

# semanage user -m -r s0:c0.c1023 user_u

# semanage user -l

                 Labeling   MLS/ MLS/
SELinux User    Prefix     MCS Level  MCS Range                      
SELinux Roles

git_shell_u     user       SystemLow SystemLow                      
git_shell_r
guest_u         user       SystemLow SystemLow                      guest_r
root            user       SystemLow SystemLow-SystemHigh           
staff_r sysadm_r system_r unconfined_r
staff_u         user       SystemLow SystemLow-SystemHigh           
staff_r sysadm_r system_r unconfined_r
sysadm_u        user       SystemLow SystemLow-SystemHigh           sysadm_r
system_u        user       SystemLow SystemLow-SystemHigh           
system_r unconfined_r
unconfined_u    user       SystemLow SystemLow-SystemHigh           
system_r unconfined_r
user_u          user       SystemLow SystemHigh                     user_r
xguest_u        user       SystemLow SystemLow                      xguest_r

# useradd kate

# passwd kate
Changing password for user kate.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# semanage login -a kate
libsemanage.validate_handler: MLS range s0 for Unix user regularuser 
exceeds allowed range s0:c0.c1023 for SELinux user user_u (No such file 
or directory).
libsemanage.validate_handler: seuser mapping [regularuser -> (user_u, 
s0)] is invalid (No such file or directory).
libsemanage.dbase_llist_iterate: could not iterate over records (No such 
file or directory).
/usr/sbin/semanage: Could not commit semanage transaction

I would greatly appreciate any other hints to make this work.

Regards,

Bill

On 5/23/2017 8:42 PM, Philip Seeley wrote:
>  Hi Bill,
>
>  This is probably because the default RHEL6 configuration does not 
>  include any categories in the user_u SELinux user's range:
>
>  # semanage user -l
>
>                  Labeling   MLS/       MLS/
>  SELinux User    Prefix     MCS Level  MCS Range                     
>   SELinux Roles
>
>  guest_u         user       s0         s0                         guest_r
>  root            user       s0 s0-s0:c0.c1023                 staff_r 
>  sysadm_r system_r unconfined_r
>  staff_u         user       s0 s0-s0:c0.c1023                 staff_r 
>  sysadm_r system_r unconfined_r
>  sysadm_u        user       s0 s0-s0:c0.c1023                 sysadm_r
>  system_u        user       s0 s0-s0:c0.c1023                 system_r 
>  unconfined_r
>  unconfined_u    user       s0 s0-s0:c0.c1023                 system_r 
>  unconfined_r
>  user_u          user       s0         s0                         user_r
>
>  You probably have to extend the user definition to include the 
>  categories you're using. As an example, this gives all categories:
>
>  # semanage user -m -r s0:c0.c1023 user_u
>
>  # semanage user -l
>
>                  Labeling   MLS/       MLS/
>  SELinux User    Prefix     MCS Level  MCS Range                     
>   SELinux Roles
>
>  guest_u         user       s0         s0                         guest_r
>  root            user       s0 s0-s0:c0.c1023                 staff_r 
>  sysadm_r system_r unconfined_r
>  staff_u         user       s0 s0-s0:c0.c1023                 staff_r 
>  sysadm_r system_r unconfined_r
>  sysadm_u        user       s0 s0-s0:c0.c1023                 sysadm_r
>  system_u        user       s0 s0-s0:c0.c1023                 system_r 
>  unconfined_r
>  unconfined_u    user       s0 s0-s0:c0.c1023                 system_r 
>  unconfined_r
>  user_u          user       s0 s0:c0.c1023                    user_r
>
>  Hope that helps.
>
>  Phil
>
>
>  Inactive hide details for Bill Durant ---24/05/2017 12:34:53---Hello 
>  Phil: Thank you for the suggestion. I have tried the stepBill Durant 
>  ---24/05/2017 12:34:53---Hello Phil: Thank you for the suggestion. I 
>  have tried the steps from the URL that
>
>  From: Bill Durant <littus(a)icloud.com&gt;
>  To: Philip Seeley <pseeley(a)au1.ibm.com&gt;
>  Cc: littus(a)icloud.com, selinux(a)lists.fedoraproject.org
>  Date: 24/05/2017 12:34
>  Subject: Re: Controlling execution of Java JAR files with SELinux RBAC
>
>  ------------------------------------------------------------------------
>
>
>
>  Hello Phil:
>
>  Thank you for the suggestion.  I have tried the steps from the URL 
>  that you provided without success.
>
>  I get an error when I try to assign Linux user mary to an SELinux 
>  login as follows:
>
>  # cat /etc/redhat-release
>  CentOS release 6.9 (Final)
>
>  ;;; Add "s0:c0=NetworkAdministrator" and "s0:c1=Operator" to 
>  /etc/selinux/targeted/setrans.conf
>
>  # cat /etc/selinux/targeted/setrans.conf
>  #
>  # Multi-Category Security translation table for SELinux
>  #
>  # Uncomment the following to disable translation libary
>  # disable=1
>  #
>  # Objects can be categorized with 0-1023 categories defined by the admin.
>  # Objects can be in more than one category at a time.
>  # Categories are stored in the system as c0-c1023.  Users can use this
>  # table to translate the categories into a more meaningful output.
>  # Examples:
>  # s0:c0=CompanyConfidential
>  # s0:c1=PatientRecord
>  # s0:c2=Unclassified
>  # s0:c3=TopSecret
>  # s0:c1,c3=CompanyConfidentialRedHat
>  s0:c0=NetworkAdministrator
>  s0:c1=Operator
>  s0=SystemLow
>  s0-s0:c0.c1023=SystemLow-SystemHigh
>  s0:c0.c1023=SystemHigh
>
>  # service mcstrans start
>
>  # chcat -L
>  s0:c0                          NetworkAdministrator
>  s0:c1                          Operator
>  s0                             SystemLow
>  s0-s0:c0.c1023                 SystemLow-SystemHigh
>  s0:c0.c1023                    SystemHigh
>
>
>  # useradd mary
>  # passwd mary
>  Changing password for user mary.
>  New password:
>  Retype new password:
>  passwd: all authentication tokens updated successfully.
>
>  # semanage login -a mary
>
>  # chcat -l -- +NetworkAdministrator mary
>  libsemanage.validate_handler: MLS range s0-s0:c0 for Unix user mary 
>  exceeds allowed range s0 for SELinux user user_u (No such file or 
>  directory).
>  libsemanage.validate_handler: seuser mapping [mary -> (user_u, 
>  s0-s0:c0)] is invalid (No such file or directory).
>  libsemanage.dbase_llist_iterate: could not iterate over records (No 
>  such file or directory).
>  /usr/sbin/semanage: Could not commit semanage transaction
>
>  I would appreciate any hints on how to resolve that error.
>
>  Thanks!
>
>  Bill
>
>
>  On 05/23/2017 05:49 PM, Philip Seeley wrote:
>
>          Hi Bill,
>
>          Have you thought about using categories?
>          _
>         
> __https://www.centos.org/docs/5/html/Deployment_Guide-en-US/sec-mcs-getst...
>
>          Cheers
>
>          Phil
>
>          Inactive hide details for Bill D ---24/05/2017
>          09:52:00---Greetings: I have been trying to figure out how to
>          control the executBill D ---24/05/2017 09:52:00---Greetings: I
>          have been trying to figure out how to control the execution of
>          Java
>
>          From: Bill D _&lt;littus(a)icloud.com&gt;_ <mailto:[e-mail]>
>          To: _selinux(a)lists.fedoraproject.org_
>          <mailto:[e-mail]>
>          Cc: _littus(a)icloud.com_ <mailto:[e-mail]>
>          Date: 24/05/2017 09:52
>          Subject: Controlling execution of Java JAR files with SELinux
>          RBAC
>          ------------------------------------------------------------------------
>
>
>
>          Greetings:
>
>          I have been trying to figure out how to control the execution
>          of Java
>          JAR files with SELinux RBAC.
>
>          I have two Linux users named joe and mary and two Java JAR
>          files named
>          jack.jar and mary.jar.
>
>          Here is how jack executes jack.jar: java -jar jack.jar
>
>          Here is how mary executes mary.jar: java -jar mary.jar
>
>          I would like SELinux RBAC to prevent jack from executing
>          mary.jar and
>          prevent mary from executing jack.jar.
>
>          How to configure SELinux RBAC to make that happen?
>
>          I have tried various approaches without success.  I have also
>          tried the
>          steps in
>          _http://forums.fedoraforum.org/archive/index.php/t-222938.html_
>          without success.
>
>          I would greatly appreciate any hints.
>
>          Regards,
>
>          Bill
>
>
>          _______________________________________________
>          selinux mailing list -- _selinux(a)lists.fedoraproject.org_
>          <mailto:[e-mail]>
>          To unsubscribe send an email to
>          _selinux-leave(a)lists.fedoraproject.org_
>          <mailto:[e-mail]>
>
>
>
>
>
>          _______________________________________________
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>          <mailto:[e-mail]>
>          To unsubscribe send an email to
>          _selinux-leave(a)lists.fedoraproject.org_
>          <mailto:[e-mail]>
>
>
>
>

[Stephen Smalley]

On Tue, 2017-05-23 at 16:51 -0700, Bill D wrote:
>  Greetings:
>  
>  I have been trying to figure out how to control the execution of
>  Java 
>  JAR files with SELinux RBAC.
>  
>  I have two Linux users named joe and mary and two Java JAR files
>  named 
>  jack.jar and mary.jar.
>  
>  Here is how jack executes jack.jar: java -jar jack.jar
>  
>  Here is how mary executes mary.jar: java -jar mary.jar 
So they aren't actually executing those files; they are both executing
java, which in turn is reading those files and interpreting the
contents.

>  I would like SELinux RBAC to prevent jack from executing mary.jar
>  and 
>  prevent mary from executing jack.jar.
>  
>  How to configure SELinux RBAC to make that happen?
>  
>  I have tried various approaches without success.  I have also tried
>  the 
>  steps in http://forums.fedoraforum.org/archive/index.php/t-222938.htm
>  l 
>  without success.
>  
>  I would greatly appreciate any hints. 
Perhaps you could describe what you tried in more detail, and how it
failed.  The thing to remember is that for your scenario above, you
need to control read permission, not execute permission.  You can
either do this via RBAC/TE (in which case you need separate SELinux
users, roles, and domains for jack and mary, and separate types for
jack.jar and mary.jar), or via MCS/MLS (in which case you need to have
jack and mary run in MCS constrained domains, authorize them for
different categories, and assign those different categories to the .jar
files).

Perhaps the better question is what is it that you are really trying to
achieve.  Merely controlling which jar files they can read/execute
isn't terribly interesting; what prevents them from just re-creating or
downloading the other .jar file themselves?

[Bill D]

On 05/24/2017 01:36 PM, Stephen Smalley wrote:

>  On Tue, 2017-05-23 at 16:51 -0700, Bill D wrote:
> > Greetings:
> >
> > I have been trying to figure out how to control the execution of
> > Java
> > JAR files with SELinux RBAC.
> >
> > I have two Linux users named joe and mary and two Java JAR files
> > named
> > jack.jar and mary.jar.
> >
> > Here is how jack executes jack.jar: java -jar jack.jar
> >
> > Here is how mary executes mary.jar: java -jar mary.jar
>  So they aren't actually executing those files; they are both executing
>  java, which in turn is reading those files and interpreting the
>  contents. 
Correct.


> > I would like SELinux RBAC to prevent jack from executing
> mary.jar
> > and
> > prevent mary from executing jack.jar.
> >
> > How to configure SELinux RBAC to make that happen?
> >
> > I have tried various approaches without success.  I have also tried
> > the
> > steps in http://forums.fedoraforum.org/archive/index.php/t-222938.htm
> > l
> > without success.
> >
> > I would greatly appreciate any hints.
>  Perhaps you could describe what you tried in more detail, and how it
>  failed.  The thing to remember is that for your scenario above, you
>  need to control read permission, not execute permission.  You can
>  either do this via RBAC/TE (in which case you need separate SELinux
>  users, roles, and domains for jack and mary, and separate types for
>  jack.jar and mary.jar), or via MCS/MLS (in which case you need to have
>  jack and mary run in MCS constrained domains, authorize them for
>  different categories, and assign those different categories to the .jar
>  files). 

Thank you for making me realize that the access control that I need is 
indeed read, not execute.

I will try again via RBAC/TE and will provide details on what I tried if 
I still cannot get it to work.

>  Perhaps the better question is what is it that you are really trying
> to
>  achieve.  Merely controlling which jar files they can read/execute
>  isn't terribly interesting; what prevents them from just re-creating or
>  downloading the other .jar file themselves? 
I am trying to implement the least privilege concept on a particular 
system.  At this point it is fine if the user copies the other JAR file 
to other systems since it will not run as expected on that other 
system.  But this may become a requirement later...

Thanks!

Bill

>  _______________________________________________
>  selinux mailing list -- selinux(a)lists.fedoraproject.org
>  To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org

[Bill D]

Hello Stephen:

I tried it via RBAC/TE without success.

How to prevent a Linux user from reading/running a Java JAR file via 
RBAC/TE?

Here is what I did:

# id -u
0

# uname -a
Linux rhel-billd 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Mar 21 12:19:18 
EDT 2017 x86_64 x86_64 x86_64 GNU/Linux

# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.9 (Santiago)

# setenforce 0

# getenforce
Permissive

# cd green

# cat green_app.te
policy_module(green_app, 0.0.1)
type green_app_t;
type green_app_exec_t;
application_executable_file(green_app_exec_t)
application_domain(green_app_t, green_app_exec_t)
role green_r types green_app_t;
require { type green_t; }
domain_auto_trans(green_t, green_app_exec_t, green_app_t)

# cat green_user.te
policy_module(green, 0.0.1)
role green_r;
userdom_unpriv_user_template(green)
gen_user(green_u, user, green_r, s0, s0)

# cat green_app.fc
/usr/local/soup/bin/green.jar -- 
gen_context(system_u:object_r:green_app_exec_t, s0)

# cp /etc/selinux/targeted/contexts/users/user_u 
/etc/selinux/targeted/contexts/users/green_u

# sed -i 's/user/green/g' /etc/selinux/targeted/contexts/users/green_u

# cat /etc/selinux/targeted/contexts/users/green_u
system_r:local_login_t:s0    green_r:green_t:s0
system_r:remote_login_t:s0    green_r:green_t:s0
system_r:sshd_t:s0        green_r:green_t:s0
system_r:crond_t:s0        green_r:green_t:s0
system_r:xdm_t:s0        green_r:green_t:s0
green_r:green_su_t:s0        green_r:green_t:s0
green_r:green_sudo_t:s0        green_r:green_t:s0
system_r:initrc_su_t:s0        green_r:green_t:s0
green_r:green_t:s0        green_r:green_t:s0

# make -f /usr/share/selinux/devel/Makefile
Compiling targeted green_app module
/usr/bin/checkmodule:  loading policy configuration from tmp/green_app.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/green_app.mod
Creating targeted green_app.pp policy package
Compiling targeted green_user module
/usr/bin/checkmodule:  loading policy configuration from tmp/green_user.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/green_user.mod
Creating targeted green_user.pp policy package
rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod 
tmp/green_app.mod.fc

# cat green_app.if
## <summary></summary>

# cat green_user.if
## <summary></summary>

# cat green_user.fc

# semodule -i green_user.pp green_app.pp

# useradd -Z green_u mary

# passwd mary
Changing password for user mary.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# restorecon -v /usr/local/soup/bin/green.jar
restorecon reset /usr/local/soup/bin/green.jar context 
system_u:object_r:bin_t:s0->system_u:object_r:green_app_exec_t:s0

# ls -Z /usr/local/soup/bin/green.jar
-rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
/usr/local/soup/bin/green.jar

# cd ../red

# cat red_app.te
policy_module(red_app, 0.0.1)
type red_app_t;
type red_app_exec_t;
application_executable_file(red_app_exec_t)
application_domain(red_app_t, red_app_exec_t)
role red_r types red_app_t;
require { type red_t; }
domain_auto_trans(red_t, red_app_exec_t, red_app_t)

# cat red_user.te
policy_module(red, 0.0.1)
role red_r;
userdom_unpriv_user_template(red)
gen_user(red_u, user, red_r, s0, s0)

# cat red_app.fc
/usr/local/soup/bin/red.jar -- 
gen_context(system_u:object_r:red_app_exec_t, s0)

# cp /etc/selinux/targeted/contexts/users/user_u 
/etc/selinux/targeted/contexts/users/red_u

# sed -i 's/user/red/g' /etc/selinux/targeted/contexts/users/red_u

# cat /etc/selinux/targeted/contexts/users/red_u
system_r:local_login_t:s0    red_r:red_t:s0
system_r:remote_login_t:s0    red_r:red_t:s0
system_r:sshd_t:s0        red_r:red_t:s0
system_r:crond_t:s0        red_r:red_t:s0
system_r:xdm_t:s0        red_r:red_t:s0
red_r:red_su_t:s0        red_r:red_t:s0
red_r:red_sudo_t:s0        red_r:red_t:s0
system_r:initrc_su_t:s0        red_r:red_t:s0
red_r:red_t:s0        red_r:red_t:s0

# make -f /usr/share/selinux/devel/Makefile
Compiling targeted red_app module
/usr/bin/checkmodule:  loading policy configuration from tmp/red_app.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/red_app.mod
Creating targeted red_app.pp policy package
Compiling targeted red_user module
/usr/bin/checkmodule:  loading policy configuration from tmp/red_user.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/red_user.mod
Creating targeted red_user.pp policy package
rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod tmp/red_app.mod.fc

# cat red_app.if
## <summary></summary>

# cat red_user.if
## <summary></summary>

# cat red_user.fc

# semodule -i red_user.pp red_app.pp

# useradd -Z red_u jack

# passwd jack
Changing password for user jack.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# restorecon -v /usr/local/soup/bin/red.jar
restorecon reset /usr/local/soup/bin/red.jar context 
system_u:object_r:bin_t:s0->system_u:object_r:red_app_exec_t:s0

# ls -Z /usr/local/soup/bin/red.jar
-rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow 
/usr/local/soup/bin/red.jar

# setenforce 1

# getenforce
Enforcing

Now logon as Linux user mary and notice that it can read/run red.jar 
which is NOT expected:

$ whoami
mary

$ id -Z
green_u:green_r:green_t:SystemLow

$ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
-rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
/usr/local/soup/bin/green.jar
-rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow 
/usr/local/soup/bin/red.jar

$ getenforce
Enforcing

$ java -jar /usr/local/soup/bin/green.jar
Hello from the green application

$ java -jar /usr/local/soup/bin/red.jar
Hello from the red application

The same situation happens with user jack as follows:

$ whoami
jack

$ id -Z
red_u:red_r:red_t:SystemLow

$ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
-rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
/usr/local/soup/bin/green.jar
-rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow 
/usr/local/soup/bin/red.jar

$ getenforce
Enforcing

$ java -jar /usr/local/soup/bin/green.jar
Hello from the green application

$ java -jar /usr/local/soup/bin/red.jar
Hello from the red application

How to prevent mary from reading/running red.jar and jack from 
running/running green.jar?

===================================

Following is how to create the JAR files:

$ whoami
admin

$ id -Z
unconfined_u:unconfined_r:unconfined_t:SystemLow-SystemHigh

$ cat Green.java
public class Green {
     public static void main(String[] args) {
         System.out.println("Hello from the green application");
     }
}

$ javac Green.java

$ cat manifest.txt
Main-Class:

$ jar cvfe green.jar Green Green.class
added manifest
adding: Green.class(in = 436) (out= 301)(deflated 30%)

$ ls -Z green.jar
-rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
green.jar

$ cat Red.java
public class Red {
     public static void main(String[] args) {
         System.out.println("Hello from the red application");
     }
}

$ javac Red.java

$ cat manifest.txt
Main-Class:

$ jar cvfe red.jar Red Red.class
added manifest
adding: Red.class(in = 430) (out= 301)(deflated 30%)

$ ls -Z red.jar
-rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow red.jar

Best Regards,

Bill
On 05/24/2017 02:19 PM, Bill D wrote:

>  On 05/24/2017 01:36 PM, Stephen Smalley wrote:
>
> > On Tue, 2017-05-23 at 16:51 -0700, Bill D wrote:
> >> Greetings:
> >>
> >> I have been trying to figure out how to control the execution of
> >> Java
> >> JAR files with SELinux RBAC.
> >>
> >> I have two Linux users named joe and mary and two Java JAR files
> >> named
> >> jack.jar and mary.jar.
> >>
> >> Here is how jack executes jack.jar: java -jar jack.jar
> >>
> >> Here is how mary executes mary.jar: java -jar mary.jar
> > So they aren't actually executing those files; they are both executing
> > java, which in turn is reading those files and interpreting the
> > contents.
>
>  Correct.
>
>
> >> I would like SELinux RBAC to prevent jack from executing mary.jar
> >> and
> >> prevent mary from executing jack.jar.
> >>
> >> How to configure SELinux RBAC to make that happen?
> >>
> >> I have tried various approaches without success.  I have also tried
> >> the
> >> steps in http://forums.fedoraforum.org/archive/index.php/t-222938.htm
> >> l
> >> without success.
> >>
> >> I would greatly appreciate any hints.
> > Perhaps you could describe what you tried in more detail, and how it
> > failed.  The thing to remember is that for your scenario above, you
> > need to control read permission, not execute permission.  You can
> > either do this via RBAC/TE (in which case you need separate SELinux
> > users, roles, and domains for jack and mary, and separate types for
> > jack.jar and mary.jar), or via MCS/MLS (in which case you need to have
> > jack and mary run in MCS constrained domains, authorize them for
> > different categories, and assign those different categories to the .jar
> > files).
>
>
>  Thank you for making me realize that the access control that I need is 
>  indeed read, not execute.
>
>  I will try again via RBAC/TE and will provide details on what I tried 
>  if I still cannot get it to work.
>
> > Perhaps the better question is what is it that you are really trying to
> > achieve.  Merely controlling which jar files they can read/execute
> > isn't terribly interesting; what prevents them from just re-creating or
> > downloading the other .jar file themselves?
>
>  I am trying to implement the least privilege concept on a particular 
>  system.  At this point it is fine if the user copies the other JAR 
>  file to other systems since it will not run as expected on that other 
>  system.  But this may become a requirement later...
>
>  Thanks!
>
>  Bill
>
> > _______________________________________________
> > selinux mailing list -- selinux(a)lists.fedoraproject.org
> > To unsubscribe send an email to selinux-leave(a)lists.fedoraproject.org
>

[Stephen Smalley]

On Thu, 2017-05-25 at 14:20 -0700, Bill D wrote:
>  Hello Stephen:
>  
>  I tried it via RBAC/TE without success.
>  
>  How to prevent a Linux user from reading/running a Java JAR file via 
>  RBAC/TE?
>  
>  Here is what I did:
>  
>  # id -u
>  0
>  
>  # uname -a
>  Linux rhel-billd 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Mar 21
>  12:19:18 
>  EDT 2017 x86_64 x86_64 x86_64 GNU/Linux
>  
>  # cat /etc/redhat-release
>  Red Hat Enterprise Linux Server release 6.9 (Santiago)
>  
>  # setenforce 0
>  
>  # getenforce
>  Permissive
>  
>  # cd green
>  
>  # cat green_app.te
>  policy_module(green_app, 0.0.1)
>  type green_app_t;
>  type green_app_exec_t;
>  application_executable_file(green_app_exec_t)
>  application_domain(green_app_t, green_app_exec_t)
>  role green_r types green_app_t;
>  require { type green_t; }
>  domain_auto_trans(green_t, green_app_exec_t, green_app_t) 
Note that most of this policy module is unnecessary/unused, because you
aren't truly executing the jar files, so there is no domain transition,
and hence neither green_app_t nor the rules generated by
application_domain() or domain_auto_trans() are ever exercised.  The
definitions you have above are more suitable to an executable program,
not a data file, and at the end of the day, a .jar file is really just
data.  I would just declare green_jar_t and make it a file_type() only.

>  
>  # cat green_user.te
>  policy_module(green, 0.0.1)
>  role green_r;
>  userdom_unpriv_user_template(green)
>  gen_user(green_u, user, green_r, s0, s0)
>  
>  # cat green_app.fc
>  /usr/local/soup/bin/green.jar -- 
>  gen_context(system_u:object_r:green_app_exec_t, s0)
>  
>  # cp /etc/selinux/targeted/contexts/users/user_u 
>  /etc/selinux/targeted/contexts/users/green_u
>  
>  # sed -i 's/user/green/g'
>  /etc/selinux/targeted/contexts/users/green_u
>  
>  # cat /etc/selinux/targeted/contexts/users/green_u
>  system_r:local_login_t:s0    green_r:green_t:s0
>  system_r:remote_login_t:s0    green_r:green_t:s0
>  system_r:sshd_t:s0        green_r:green_t:s0
>  system_r:crond_t:s0        green_r:green_t:s0
>  system_r:xdm_t:s0        green_r:green_t:s0
>  green_r:green_su_t:s0        green_r:green_t:s0
>  green_r:green_sudo_t:s0        green_r:green_t:s0
>  system_r:initrc_su_t:s0        green_r:green_t:s0
>  green_r:green_t:s0        green_r:green_t:s0
>  
>  # make -f /usr/share/selinux/devel/Makefile
>  Compiling targeted green_app module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/green_app.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/green_app.mod
>  Creating targeted green_app.pp policy package
>  Compiling targeted green_user module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/green_user.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/green_user.mod
>  Creating targeted green_user.pp policy package
>  rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod 
>  tmp/green_app.mod.fc
>  
>  # cat green_app.if
>  ## <summary></summary>
>  
>  # cat green_user.if
>  ## <summary></summary>
>  
>  # cat green_user.fc
>  
>  # semodule -i green_user.pp green_app.pp
>  
>  # useradd -Z green_u mary
>  
>  # passwd mary
>  Changing password for user mary.
>  New password:
>  Retype new password:
>  passwd: all authentication tokens updated successfully.
>  
>  # restorecon -v /usr/local/soup/bin/green.jar
>  restorecon reset /usr/local/soup/bin/green.jar context 
>  system_u:object_r:bin_t:s0->system_u:object_r:green_app_exec_t:s0
>  
>  # ls -Z /usr/local/soup/bin/green.jar
>  -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
>  /usr/local/soup/bin/green.jar
>  
>  # cd ../red
>  
>  # cat red_app.te
>  policy_module(red_app, 0.0.1)
>  type red_app_t;
>  type red_app_exec_t;
>  application_executable_file(red_app_exec_t)
>  application_domain(red_app_t, red_app_exec_t)
>  role red_r types red_app_t;
>  require { type red_t; }
>  domain_auto_trans(red_t, red_app_exec_t, red_app_t) 
Same as for green_app.te above.

>  
>  # cat red_user.te
>  policy_module(red, 0.0.1)
>  role red_r;
>  userdom_unpriv_user_template(red)
>  gen_user(red_u, user, red_r, s0, s0)
>  
>  # cat red_app.fc
>  /usr/local/soup/bin/red.jar -- 
>  gen_context(system_u:object_r:red_app_exec_t, s0)
>  
>  # cp /etc/selinux/targeted/contexts/users/user_u 
>  /etc/selinux/targeted/contexts/users/red_u
>  
>  # sed -i 's/user/red/g' /etc/selinux/targeted/contexts/users/red_u
>  
>  # cat /etc/selinux/targeted/contexts/users/red_u
>  system_r:local_login_t:s0    red_r:red_t:s0
>  system_r:remote_login_t:s0    red_r:red_t:s0
>  system_r:sshd_t:s0        red_r:red_t:s0
>  system_r:crond_t:s0        red_r:red_t:s0
>  system_r:xdm_t:s0        red_r:red_t:s0
>  red_r:red_su_t:s0        red_r:red_t:s0
>  red_r:red_sudo_t:s0        red_r:red_t:s0
>  system_r:initrc_su_t:s0        red_r:red_t:s0
>  red_r:red_t:s0        red_r:red_t:s0
>  
>  # make -f /usr/share/selinux/devel/Makefile
>  Compiling targeted red_app module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/red_app.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/red_app.mod
>  Creating targeted red_app.pp policy package
>  Compiling targeted red_user module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/red_user.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/red_user.mod
>  Creating targeted red_user.pp policy package
>  rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod
>  tmp/red_app.mod.fc
>  
>  # cat red_app.if
>  ## <summary></summary>
>  
>  # cat red_user.if
>  ## <summary></summary>
>  
>  # cat red_user.fc
>  
>  # semodule -i red_user.pp red_app.pp
>  
>  # useradd -Z red_u jack
>  
>  # passwd jack
>  Changing password for user jack.
>  New password:
>  Retype new password:
>  passwd: all authentication tokens updated successfully.
>  
>  # restorecon -v /usr/local/soup/bin/red.jar
>  restorecon reset /usr/local/soup/bin/red.jar context 
>  system_u:object_r:bin_t:s0->system_u:object_r:red_app_exec_t:s0
>  
>  # ls -Z /usr/local/soup/bin/red.jar
>  -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow 
>  /usr/local/soup/bin/red.jar
>  
>  # setenforce 1
>  
>  # getenforce
>  Enforcing
>  
>  Now logon as Linux user mary and notice that it can read/run red.jar 
>  which is NOT expected:
>  
>  $ whoami
>  mary
>  
>  $ id -Z
>  green_u:green_r:green_t:SystemLow
>  
>  $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
>  -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
>  /usr/local/soup/bin/green.jar
>  -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow 
>  /usr/local/soup/bin/red.jar
>  
>  $ getenforce
>  Enforcing
>  
>  $ java -jar /usr/local/soup/bin/green.jar
>  Hello from the green application
>  
>  $ java -jar /usr/local/soup/bin/red.jar
>  Hello from the red application 
So at this point you can query the policy to understand what is
allowing this access:
yum install setools-console
sesearch -A -s green_t -t red_app_exec_t -c file
Found 1 semantic av rules:
   allow green_usertype application_exec_type : file { ioctl read
getattr lock execute execute_no_trans open } ;

And if we look at the refpolicy headers, we see that all user domains
are allowed to read/execute all applications:
# grep -n application_exec
/usr/share/selinux/devel/include/system/userdomain.if 
72:	application_exec_all($1_usertype)

So by declaring the types as application_executable_file(), you allowed
all user domains to read/execute them. If you only make them
file_type(), then they won't be immediately readable/executable by all
user domains.

Depending on your goals, you may find that refpolicy's
userdom_unpriv_user_template() is too liberal in what it allows and you
may want to define your own, more minimalist set.

Questions/comments about refpolicy interfaces and implementation should
go to the refpolicy mailing list,
http://oss.tresys.com/mailman/listinfo/refpolicy

> 
> The same situation happens with user jack as follows:
> 
> $ whoami
> jack
> 
> $ id -Z
> red_u:red_r:red_t:SystemLow
> 
> $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
> -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
> /usr/local/soup/bin/green.jar
> -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow 
> /usr/local/soup/bin/red.jar
> 
> $ getenforce
> Enforcing
> 
> $ java -jar /usr/local/soup/bin/green.jar
> Hello from the green application
> 
> $ java -jar /usr/local/soup/bin/red.jar
> Hello from the red application
> 
> How to prevent mary from reading/running red.jar and jack from 
> running/running green.jar?
> 
> ===================================
> 
> Following is how to create the JAR files:
> 
> $ whoami
> admin
> 
> $ id -Z
> unconfined_u:unconfined_r:unconfined_t:SystemLow-SystemHigh
> 
> $ cat Green.java
> public class Green {
>      public static void main(String[] args) {
>          System.out.println("Hello from the green application");
>      }
> }
> 
> $ javac Green.java
> 
> $ cat manifest.txt
> Main-Class:
> 
> $ jar cvfe green.jar Green Green.class
> added manifest
> adding: Green.class(in = 436) (out= 301)(deflated 30%)
> 
> $ ls -Z green.jar
> -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow 
> green.jar
> 
> $ cat Red.java
> public class Red {
>      public static void main(String[] args) {
>          System.out.println("Hello from the red application");
>      }
> }
> 
> $ javac Red.java
> 
> $ cat manifest.txt
> Main-Class:
> 
> $ jar cvfe red.jar Red Red.class
> added manifest
> adding: Red.class(in = 430) (out= 301)(deflated 30%)
> 
> $ ls -Z red.jar
> -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow
> red.jar
> 
> Best Regards,
> 
> Bill
> On 05/24/2017 02:19 PM, Bill D wrote:
> 
> > On 05/24/2017 01:36 PM, Stephen Smalley wrote:
> > 
> > > On Tue, 2017-05-23 at 16:51 -0700, Bill D wrote:
> > > > Greetings:
> > > > 
> > > > I have been trying to figure out how to control the execution
> > > > of
> > > > Java
> > > > JAR files with SELinux RBAC.
> > > > 
> > > > I have two Linux users named joe and mary and two Java JAR
> > > > files
> > > > named
> > > > jack.jar and mary.jar.
> > > > 
> > > > Here is how jack executes jack.jar: java -jar jack.jar
> > > > 
> > > > Here is how mary executes mary.jar: java -jar mary.jar
> > > 
> > > So they aren't actually executing those files; they are both
> > > executing
> > > java, which in turn is reading those files and interpreting the
> > > contents.
> > 
> > Correct.
> > 
> > 
> > > > I would like SELinux RBAC to prevent jack from executing
> > > > mary.jar
> > > > and
> > > > prevent mary from executing jack.jar.
> > > > 
> > > > How to configure SELinux RBAC to make that happen?
> > > > 
> > > > I have tried various approaches without success.  I have also
> > > > tried
> > > > the
> > > > steps in http://forums.fedoraforum.org/archive/index.php/t-2229
> > > > 38.htm
> > > > l
> > > > without success.
> > > > 
> > > > I would greatly appreciate any hints.
> > > 
> > > Perhaps you could describe what you tried in more detail, and how
> > > it
> > > failed.  The thing to remember is that for your scenario above,
> > > you
> > > need to control read permission, not execute permission.  You can
> > > either do this via RBAC/TE (in which case you need separate
> > > SELinux
> > > users, roles, and domains for jack and mary, and separate types
> > > for
> > > jack.jar and mary.jar), or via MCS/MLS (in which case you need to
> > > have
> > > jack and mary run in MCS constrained domains, authorize them for
> > > different categories, and assign those different categories to
> > > the .jar
> > > files).
> > 
> > 
> > Thank you for making me realize that the access control that I need
> > is 
> > indeed read, not execute.
> > 
> > I will try again via RBAC/TE and will provide details on what I
> > tried 
> > if I still cannot get it to work.
> > 
> > > Perhaps the better question is what is it that you are really
> > > trying to
> > > achieve.  Merely controlling which jar files they can
> > > read/execute
> > > isn't terribly interesting; what prevents them from just re-
> > > creating or
> > > downloading the other .jar file themselves?
> > 
> > I am trying to implement the least privilege concept on a
> > particular 
> > system.  At this point it is fine if the user copies the other JAR 
> > file to other systems since it will not run as expected on that
> > other 
> > system.  But this may become a requirement later...
> > 
> > Thanks!
> > 
> > Bill
> > 
> > > _______________________________________________
> > > selinux mailing list -- selinux(a)lists.fedoraproject.org
> > > To unsubscribe send an email to selinux-leave(a)lists.fedoraproject
> > > .org

[Bill Durant]

Hello Stephen:

I went ahead and tried to just declare green_jar_t and made it a file 
type as you have suggested but I think I may have something wrong with 
the TE policy that I created.  Here is what I did and the error that I 
am getting:

# uname -a
Linux es300h 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Apr 11 17:13:24 UTC 
2017 x86_64 x86_64 x86_64 GNU/Linux

# cat /etc/redhat-release
CentOS release 6.9 (Final)

# whoami
root

# setenforce 0

# cp /etc/selinux/targeted/contexts/users/user_u 
/etc/selinux/targeted/contexts/users/red_u
# cp /etc/selinux/targeted/contexts/users/user_u 
/etc/selinux/targeted/contexts/users/green_u
# sed -i 's/user/red/g' /etc/selinux/targeted/contexts/users/red_u
# sed -i 's/user/green/g' /etc/selinux/targeted/contexts/users/green_u

# cd red

# cat red_user.te
policy_module(red, 0.0.1)
role red_r;
userdom_unpriv_user_template(red)
gen_user(red_u, user, red_r, s0, s0)

# cat red_app.te
policy_module(red_app, 0.0.1)
type red_jar_t;
files_type(red_jar_t)
role red_r types red_jar_t;

# cat red_app.fc
/usr/local/soup/bin/red.jar -- gen_context(system_u:object_r:red_jar_t, s0)

# make -f /usr/share/selinux/devel/Makefile
Compiling targeted red_app module
/usr/bin/checkmodule:  loading policy configuration from tmp/red_app.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/red_app.mod
Creating targeted red_app.pp policy package
Compiling targeted red_user module
/usr/bin/checkmodule:  loading policy configuration from tmp/red_user.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/red_user.mod
Creating targeted red_user.pp policy package
rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod tmp/red_app.mod.fc

# semodule -i red_user.pp red_app.pp

# restorecon -v /usr/local/soup/bin/red.jar
restorecon reset /usr/local/soup/bin/red.jar context 
system_u:object_r:bin_t:s0->system_u:object_r:red_jar_t:s0

# ls -Z /usr/local/soup/bin/red.jar
-rwxr-xr-x. root root system_u:object_r:red_jar_t:s0 
/usr/local/soup/bin/red.jar

# cd ../green

# cat green_user.te
policy_module(green, 0.0.1)
role green_r;
userdom_unpriv_user_template(green)
gen_user(green_u, user, green_r, s0, s0)

# cat green_app.te
policy_module(green_app, 0.0.1)
type green_jar_t;
files_type(green_jar_t)
role green_r types green_jar_t;

# cat green_app.fc
/usr/local/soup/bin/green.jar -- 
gen_context(system_u:object_r:green_jar_t, s0)

# make -f /usr/share/selinux/devel/Makefile
Compiling targeted green_app module
/usr/bin/checkmodule:  loading policy configuration from tmp/green_app.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/green_app.mod
Creating targeted green_app.pp policy package
Compiling targeted green_user module
/usr/bin/checkmodule:  loading policy configuration from tmp/green_user.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/green_user.mod
Creating targeted green_user.pp policy package
rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod 
tmp/green_app.mod.fc

# semodule -i green_user.pp green_app.pp

# restorecon -v /usr/local/soup/bin/green.jar
restorecon reset /usr/local/soup/bin/green.jar context 
system_u:object_r:bin_t:s0->system_u:object_r:green_jar_t:s0

# ls -Z /usr/local/soup/bin/green.jar
-rwxr-xr-x. root root system_u:object_r:green_jar_t:s0 
/usr/local/soup/bin/green.jar

# useradd -Z green_u mary

# useradd -Z red_u jack

# passwd mary
Changing password for user mary.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# passwd jack
Changing password for user jack.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# setenforce 1

Now login as Linux user mary and notice that java is unable to read the 
JAR file which is NOT expected:

$ whoami
mary

$ java -jar /usr/local/soup/bin/green.jar
Error: Unable to access jarfile /usr/local/soup/bin/green.jar

Now let's try to fix that with audit2allow:

 From /var/log/audit/audit.log:
...
...
type=AVC msg=audit(1496085668.816:22282): avc:  denied  { read } for  
pid=10657 comm="java" name="green.jar" dev=dm-0 ino=934010 
scontext=green_u:green_r:green_java_t:s0 
tcontext=system_u:object_r:green_jar_t:s0 tclass=file

...
...

# grep java /var/log/audit/audit.log | audit2allow -m java > foo.te

# cat foo.te

module java 1.0;

require {
     type user_tmp_t;
     type green_java_t;
     type vmblock_t;
     type sshd_t;
     type sysctl_fs_t;
     type usr_t;
     type green_jar_t;
     class dir { getattr search };
     class file { read execute append };
}

#============= green_java_t ==============
allow green_java_t green_jar_t:file read;

#============= sshd_t ==============
allow sshd_t sysctl_fs_t:dir search;
allow sshd_t user_tmp_t:file execute;
allow sshd_t usr_t:file append;
allow sshd_t vmblock_t:dir getattr;

# make -f /usr/share/selinux/devel/Makefile
Compiling targeted foo module
/usr/bin/checkmodule:  loading policy configuration from tmp/foo.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/foo.mod
Creating targeted foo.pp policy package
rm tmp/foo.mod.fc tmp/foo.mod

# semodule -i foo.pp
libsepol.print_missing_requirements: java's global requirements were not 
met: type/attribute green_java_t (No such file or directory).
libsemanage.semanage_link_sandbox: Link packages failed (No such file or 
directory).
semodule:  Failed!
You have new mail in /var/spool/mail/root

# sesearch -A -s green_java_t -t green_jar_t -c file
Found 1 semantic av rules:
    allow green_java_t file_type : file execmod ;

What am I missing?

Thank you & Best Regards,

Bill

P.S. I have subscribed to the refpolicy mailing list but I am still 
waiting for my subscription request to get accepted.

On 05/26/2017 06:58 AM, Stephen Smalley wrote:
>  On Thu, 2017-05-25 at 14:20 -0700, Bill D wrote:
> > Hello Stephen:
> >
> > I tried it via RBAC/TE without success.
> >
> > How to prevent a Linux user from reading/running a Java JAR file via
> > RBAC/TE?
> >
> > Here is what I did:
> >
> > # id -u
> > 0
> >
> > # uname -a
> > Linux rhel-billd 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Mar 21
> > 12:19:18
> > EDT 2017 x86_64 x86_64 x86_64 GNU/Linux
> >
> > # cat /etc/redhat-release
> > Red Hat Enterprise Linux Server release 6.9 (Santiago)
> >
> > # setenforce 0
> >
> > # getenforce
> > Permissive
> >
> > # cd green
> >
> > # cat green_app.te
> > policy_module(green_app, 0.0.1)
> > type green_app_t;
> > type green_app_exec_t;
> > application_executable_file(green_app_exec_t)
> > application_domain(green_app_t, green_app_exec_t)
> > role green_r types green_app_t;
> > require { type green_t; }
> > domain_auto_trans(green_t, green_app_exec_t, green_app_t)
>  Note that most of this policy module is unnecessary/unused, because you
>  aren't truly executing the jar files, so there is no domain transition,
>  and hence neither green_app_t nor the rules generated by
>  application_domain() or domain_auto_trans() are ever exercised.  The
>  definitions you have above are more suitable to an executable program,
>  not a data file, and at the end of the day, a .jar file is really just
>  data.  I would just declare green_jar_t and make it a file_type() only.
>
> > # cat green_user.te
> > policy_module(green, 0.0.1)
> > role green_r;
> > userdom_unpriv_user_template(green)
> > gen_user(green_u, user, green_r, s0, s0)
> >
> > # cat green_app.fc
> > /usr/local/soup/bin/green.jar --
> > gen_context(system_u:object_r:green_app_exec_t, s0)
> >
> > # cp /etc/selinux/targeted/contexts/users/user_u
> > /etc/selinux/targeted/contexts/users/green_u
> >
> > # sed -i 's/user/green/g'
> > /etc/selinux/targeted/contexts/users/green_u
> >
> > # cat /etc/selinux/targeted/contexts/users/green_u
> > system_r:local_login_t:s0    green_r:green_t:s0
> > system_r:remote_login_t:s0    green_r:green_t:s0
> > system_r:sshd_t:s0        green_r:green_t:s0
> > system_r:crond_t:s0        green_r:green_t:s0
> > system_r:xdm_t:s0        green_r:green_t:s0
> > green_r:green_su_t:s0        green_r:green_t:s0
> > green_r:green_sudo_t:s0        green_r:green_t:s0
> > system_r:initrc_su_t:s0        green_r:green_t:s0
> > green_r:green_t:s0        green_r:green_t:s0
> >
> > # make -f /usr/share/selinux/devel/Makefile
> > Compiling targeted green_app module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/green_app.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/green_app.mod
> > Creating targeted green_app.pp policy package
> > Compiling targeted green_user module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/green_user.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/green_user.mod
> > Creating targeted green_user.pp policy package
> > rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod
> > tmp/green_app.mod.fc
> >
> > # cat green_app.if
> > ## <summary></summary>
> >
> > # cat green_user.if
> > ## <summary></summary>
> >
> > # cat green_user.fc
> >
> > # semodule -i green_user.pp green_app.pp
> >
> > # useradd -Z green_u mary
> >
> > # passwd mary
> > Changing password for user mary.
> > New password:
> > Retype new password:
> > passwd: all authentication tokens updated successfully.
> >
> > # restorecon -v /usr/local/soup/bin/green.jar
> > restorecon reset /usr/local/soup/bin/green.jar context
> > system_u:object_r:bin_t:s0->system_u:object_r:green_app_exec_t:s0
> >
> > # ls -Z /usr/local/soup/bin/green.jar
> > -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow
> > /usr/local/soup/bin/green.jar
> >
> > # cd ../red
> >
> > # cat red_app.te
> > policy_module(red_app, 0.0.1)
> > type red_app_t;
> > type red_app_exec_t;
> > application_executable_file(red_app_exec_t)
> > application_domain(red_app_t, red_app_exec_t)
> > role red_r types red_app_t;
> > require { type red_t; }
> > domain_auto_trans(red_t, red_app_exec_t, red_app_t)
>  Same as for green_app.te above.
>
> > # cat red_user.te
> > policy_module(red, 0.0.1)
> > role red_r;
> > userdom_unpriv_user_template(red)
> > gen_user(red_u, user, red_r, s0, s0)
> >
> > # cat red_app.fc
> > /usr/local/soup/bin/red.jar --
> > gen_context(system_u:object_r:red_app_exec_t, s0)
> >
> > # cp /etc/selinux/targeted/contexts/users/user_u
> > /etc/selinux/targeted/contexts/users/red_u
> >
> > # sed -i 's/user/red/g' /etc/selinux/targeted/contexts/users/red_u
> >
> > # cat /etc/selinux/targeted/contexts/users/red_u
> > system_r:local_login_t:s0    red_r:red_t:s0
> > system_r:remote_login_t:s0    red_r:red_t:s0
> > system_r:sshd_t:s0        red_r:red_t:s0
> > system_r:crond_t:s0        red_r:red_t:s0
> > system_r:xdm_t:s0        red_r:red_t:s0
> > red_r:red_su_t:s0        red_r:red_t:s0
> > red_r:red_sudo_t:s0        red_r:red_t:s0
> > system_r:initrc_su_t:s0        red_r:red_t:s0
> > red_r:red_t:s0        red_r:red_t:s0
> >
> > # make -f /usr/share/selinux/devel/Makefile
> > Compiling targeted red_app module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/red_app.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/red_app.mod
> > Creating targeted red_app.pp policy package
> > Compiling targeted red_user module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/red_user.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/red_user.mod
> > Creating targeted red_user.pp policy package
> > rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod
> > tmp/red_app.mod.fc
> >
> > # cat red_app.if
> > ## <summary></summary>
> >
> > # cat red_user.if
> > ## <summary></summary>
> >
> > # cat red_user.fc
> >
> > # semodule -i red_user.pp red_app.pp
> >
> > # useradd -Z red_u jack
> >
> > # passwd jack
> > Changing password for user jack.
> > New password:
> > Retype new password:
> > passwd: all authentication tokens updated successfully.
> >
> > # restorecon -v /usr/local/soup/bin/red.jar
> > restorecon reset /usr/local/soup/bin/red.jar context
> > system_u:object_r:bin_t:s0->system_u:object_r:red_app_exec_t:s0
> >
> > # ls -Z /usr/local/soup/bin/red.jar
> > -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow
> > /usr/local/soup/bin/red.jar
> >
> > # setenforce 1
> >
> > # getenforce
> > Enforcing
> >
> > Now logon as Linux user mary and notice that it can read/run red.jar
> > which is NOT expected:
> >
> > $ whoami
> > mary
> >
> > $ id -Z
> > green_u:green_r:green_t:SystemLow
> >
> > $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
> > -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow
> > /usr/local/soup/bin/green.jar
> > -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow
> > /usr/local/soup/bin/red.jar
> >
> > $ getenforce
> > Enforcing
> >
> > $ java -jar /usr/local/soup/bin/green.jar
> > Hello from the green application
> >
> > $ java -jar /usr/local/soup/bin/red.jar
> > Hello from the red application
>  So at this point you can query the policy to understand what is
>  allowing this access:
>  yum install setools-console
>  sesearch -A -s green_t -t red_app_exec_t -c file
>  Found 1 semantic av rules:
>      allow green_usertype application_exec_type : file { ioctl read
>  getattr lock execute execute_no_trans open } ;
>
>  And if we look at the refpolicy headers, we see that all user domains
>  are allowed to read/execute all applications:
>  # grep -n application_exec
>  /usr/share/selinux/devel/include/system/userdomain.if
>  72:	application_exec_all($1_usertype)
>
>  So by declaring the types as application_executable_file(), you allowed
>  all user domains to read/execute them. If you only make them
>  file_type(), then they won't be immediately readable/executable by all
>  user domains.
>
>  Depending on your goals, you may find that refpolicy's
>  userdom_unpriv_user_template() is too liberal in what it allows and you
>  may want to define your own, more minimalist set.
>
>  Questions/comments about refpolicy interfaces and implementation should
>  go to the refpolicy mailing list,
>  http://oss.tresys.com/mailman/listinfo/refpolicy
>
> > The same situation happens with user jack as follows:
> >
> > $ whoami
> > jack
> >
> > $ id -Z
> > red_u:red_r:red_t:SystemLow
> >
> > $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
> > -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow
> > /usr/local/soup/bin/green.jar
> > -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow
> > /usr/local/soup/bin/red.jar
> >
> > $ getenforce
> > Enforcing
> >
> > $ java -jar /usr/local/soup/bin/green.jar
> > Hello from the green application
> >
> > $ java -jar /usr/local/soup/bin/red.jar
> > Hello from the red application
> >
> > How to prevent mary from reading/running red.jar and jack from
> > running/running green.jar?
> >
> > ===================================
> >
> > Following is how to create the JAR files:
> >
> > $ whoami
> > admin
> >
> > $ id -Z
> > unconfined_u:unconfined_r:unconfined_t:SystemLow-SystemHigh
> >
> > $ cat Green.java
> > public class Green {
> >       public static void main(String[] args) {
> >           System.out.println("Hello from the green application");
> >       }
> > }
> >
> > $ javac Green.java
> >
> > $ cat manifest.txt
> > Main-Class:
> >
> > $ jar cvfe green.jar Green Green.class
> > added manifest
> > adding: Green.class(in = 436) (out= 301)(deflated 30%)
> >
> > $ ls -Z green.jar
> > -rwxr-xr-x. admin admin system_u:object_r:green_app_exec_t:SystemLow
> > green.jar
> >
> > $ cat Red.java
> > public class Red {
> >       public static void main(String[] args) {
> >           System.out.println("Hello from the red application");
> >       }
> > }
> >
> > $ javac Red.java
> >
> > $ cat manifest.txt
> > Main-Class:
> >
> > $ jar cvfe red.jar Red Red.class
> > added manifest
> > adding: Red.class(in = 430) (out= 301)(deflated 30%)
> >
> > $ ls -Z red.jar
> > -rwxr-xr-x. admin admin system_u:object_r:red_app_exec_t:SystemLow
> > red.jar
> >
> > Best Regards,
> >
> > Bill
> > On 05/24/2017 02:19 PM, Bill D wrote:
> >
> >> On 05/24/2017 01:36 PM, Stephen Smalley wrote:
> >>
> >>> On Tue, 2017-05-23 at 16:51 -0700, Bill D wrote:
> >>>> Greetings:
> >>>>
> >>>> I have been trying to figure out how to control the execution
> >>>> of
> >>>> Java
> >>>> JAR files with SELinux RBAC.
> >>>>
> >>>> I have two Linux users named joe and mary and two Java JAR
> >>>> files
> >>>> named
> >>>> jack.jar and mary.jar.
> >>>>
> >>>> Here is how jack executes jack.jar: java -jar jack.jar
> >>>>
> >>>> Here is how mary executes mary.jar: java -jar mary.jar
> >>> So they aren't actually executing those files; they are both
> >>> executing
> >>> java, which in turn is reading those files and interpreting the
> >>> contents.
> >> Correct.
> >>
> >>
> >>>> I would like SELinux RBAC to prevent jack from executing
> >>>> mary.jar
> >>>> and
> >>>> prevent mary from executing jack.jar.
> >>>>
> >>>> How to configure SELinux RBAC to make that happen?
> >>>>
> >>>> I have tried various approaches without success.  I have also
> >>>> tried
> >>>> the
> >>>> steps in http://forums.fedoraforum.org/archive/index.php/t-2229
> >>>> 38.htm
> >>>> l
> >>>> without success.
> >>>>
> >>>> I would greatly appreciate any hints.
> >>> Perhaps you could describe what you tried in more detail, and how
> >>> it
> >>> failed.  The thing to remember is that for your scenario above,
> >>> you
> >>> need to control read permission, not execute permission.  You can
> >>> either do this via RBAC/TE (in which case you need separate
> >>> SELinux
> >>> users, roles, and domains for jack and mary, and separate types
> >>> for
> >>> jack.jar and mary.jar), or via MCS/MLS (in which case you need to
> >>> have
> >>> jack and mary run in MCS constrained domains, authorize them for
> >>> different categories, and assign those different categories to
> >>> the .jar
> >>> files).
> >>
> >> Thank you for making me realize that the access control that I need
> >> is
> >> indeed read, not execute.
> >>
> >> I will try again via RBAC/TE and will provide details on what I
> >> tried
> >> if I still cannot get it to work.
> >>
> >>> Perhaps the better question is what is it that you are really
> >>> trying to
> >>> achieve.  Merely controlling which jar files they can
> >>> read/execute
> >>> isn't terribly interesting; what prevents them from just re-
> >>> creating or
> >>> downloading the other .jar file themselves?
> >> I am trying to implement the least privilege concept on a
> >> particular
> >> system.  At this point it is fine if the user copies the other JAR
> >> file to other systems since it will not run as expected on that
> >> other
> >> system.  But this may become a requirement later...
> >>
> >> Thanks!
> >>
> >> Bill
> >>
> >>> _______________________________________________
> >>> selinux mailing list -- selinux(a)lists.fedoraproject.org
> >>> To unsubscribe send an email to selinux-leave(a)lists.fedoraproject
> >>> .org

[Stephen Smalley]

On Mon, 2017-05-29 at 12:43 -0700, Bill Durant wrote:
>  Hello Stephen:
>  
>  I went ahead and tried to just declare green_jar_t and made it a
>  file 
>  type as you have suggested but I think I may have something wrong
>  with 
>  the TE policy that I created.  Here is what I did and the error that
>  I 
>  am getting:
>  
>  # uname -a
>  Linux es300h 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Apr 11 17:13:24
>  UTC 
>  2017 x86_64 x86_64 x86_64 GNU/Linux
>  
>  # cat /etc/redhat-release
>  CentOS release 6.9 (Final)
>  
>  # whoami
>  root
>  
>  # setenforce 0
>  
>  # cp /etc/selinux/targeted/contexts/users/user_u 
>  /etc/selinux/targeted/contexts/users/red_u
>  # cp /etc/selinux/targeted/contexts/users/user_u 
>  /etc/selinux/targeted/contexts/users/green_u
>  # sed -i 's/user/red/g' /etc/selinux/targeted/contexts/users/red_u
>  # sed -i 's/user/green/g'
>  /etc/selinux/targeted/contexts/users/green_u
>  
>  # cd red
>  
>  # cat red_user.te
>  policy_module(red, 0.0.1)
>  role red_r;
>  userdom_unpriv_user_template(red)
>  gen_user(red_u, user, red_r, s0, s0)
>  
>  # cat red_app.te
>  policy_module(red_app, 0.0.1)
>  type red_jar_t;
>  files_type(red_jar_t)
>  role red_r types red_jar_t; 
You don't need the above role statement, because red_jar_t is only used
as a file type (with object_r), never as a process type/domain.

>  
>  # cat red_app.fc
>  /usr/local/soup/bin/red.jar --
>  gen_context(system_u:object_r:red_jar_t, s0)
>  
>  # make -f /usr/share/selinux/devel/Makefile
>  Compiling targeted red_app module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/red_app.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/red_app.mod
>  Creating targeted red_app.pp policy package
>  Compiling targeted red_user module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/red_user.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/red_user.mod
>  Creating targeted red_user.pp policy package
>  rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod
>  tmp/red_app.mod.fc
>  
>  # semodule -i red_user.pp red_app.pp
>  
>  # restorecon -v /usr/local/soup/bin/red.jar
>  restorecon reset /usr/local/soup/bin/red.jar context 
>  system_u:object_r:bin_t:s0->system_u:object_r:red_jar_t:s0
>  
>  # ls -Z /usr/local/soup/bin/red.jar
>  -rwxr-xr-x. root root system_u:object_r:red_jar_t:s0 
>  /usr/local/soup/bin/red.jar
>  
>  # cd ../green
>  
>  # cat green_user.te
>  policy_module(green, 0.0.1)
>  role green_r;
>  userdom_unpriv_user_template(green)
>  gen_user(green_u, user, green_r, s0, s0)
>  
>  # cat green_app.te
>  policy_module(green_app, 0.0.1)
>  type green_jar_t;
>  files_type(green_jar_t)
>  role green_r types green_jar_t; 
Likewise for the above role statement.

>  
>  # cat green_app.fc
>  /usr/local/soup/bin/green.jar -- 
>  gen_context(system_u:object_r:green_jar_t, s0)
>  
>  # make -f /usr/share/selinux/devel/Makefile
>  Compiling targeted green_app module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/green_app.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/green_app.mod
>  Creating targeted green_app.pp policy package
>  Compiling targeted green_user module
>  /usr/bin/checkmodule:  loading policy configuration from
>  tmp/green_user.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/green_user.mod
>  Creating targeted green_user.pp policy package
>  rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod 
>  tmp/green_app.mod.fc
>  
>  # semodule -i green_user.pp green_app.pp
>  
>  # restorecon -v /usr/local/soup/bin/green.jar
>  restorecon reset /usr/local/soup/bin/green.jar context 
>  system_u:object_r:bin_t:s0->system_u:object_r:green_jar_t:s0
>  
>  # ls -Z /usr/local/soup/bin/green.jar
>  -rwxr-xr-x. root root system_u:object_r:green_jar_t:s0 
>  /usr/local/soup/bin/green.jar
>  
>  # useradd -Z green_u mary
>  
>  # useradd -Z red_u jack
>  
>  # passwd mary
>  Changing password for user mary.
>  New password:
>  Retype new password:
>  passwd: all authentication tokens updated successfully.
>  
>  # passwd jack
>  Changing password for user jack.
>  New password:
>  Retype new password:
>  passwd: all authentication tokens updated successfully.
>  
>  # setenforce 1
>  
>  Now login as Linux user mary and notice that java is unable to read
>  the 
>  JAR file which is NOT expected:
>  
>  $ whoami
>  mary
>  
>  $ java -jar /usr/local/soup/bin/green.jar
>  Error: Unable to access jarfile /usr/local/soup/bin/green.jar
>  
>  Now let's try to fix that with audit2allow:
>  
>   From /var/log/audit/audit.log:
>  ...
>  ...
>  type=AVC msg=audit(1496085668.816:22282): avc:  denied  { read }
>  for  
>  pid=10657 comm="java" name="green.jar" dev=dm-0 ino=934010 
>  scontext=green_u:green_r:green_java_t:s0 
>  tcontext=system_u:object_r:green_jar_t:s0 tclass=file
>  
>  ...
>  ...
>  
>  # grep java /var/log/audit/audit.log | audit2allow -m java > foo.te
>  
>  # cat foo.te
>  
>  module java 1.0;
>  
>  require {
>       type user_tmp_t;
>       type green_java_t;
>       type vmblock_t;
>       type sshd_t;
>       type sysctl_fs_t;
>       type usr_t;
>       type green_jar_t;
>       class dir { getattr search };
>       class file { read execute append };
>  }
>  
>  #============= green_java_t ==============
>  allow green_java_t green_jar_t:file read;
>  
>  #============= sshd_t ==============
>  allow sshd_t sysctl_fs_t:dir search;
>  allow sshd_t user_tmp_t:file execute;
>  allow sshd_t usr_t:file append;
>  allow sshd_t vmblock_t:dir getattr; 
There are several problems with this policy module:
1) You named it "java", and therefore it will replace the refpolicy
java policy module when you try to install it (that's why you get the
error below, because you are removing the java module definitions when
you insert this one).

2) You included several unrelated requires and allow rules above that
have nothing to do with this denial.  You want to be more selective in
what you select with ausearch or remove the extraneous ones afterward.

3) You will need more than just read permission ultimately (e.g. open,
possibly others).  Better to use a refpolicy macro instead.

So, for example, I would write this as:
policy_module(greenjava, 1.0)
require {
	type green_java_t;
	type green_jar_t;
}
allow green_java_t green_jar_t:file read_file_perms;

And probably I would just insert the above requires and allow rules
into your already existing green_app.te module instead of creating a
separate one.

>  
>  # make -f /usr/share/selinux/devel/Makefile
>  Compiling targeted foo module
>  /usr/bin/checkmodule:  loading policy configuration from tmp/foo.tmp
>  /usr/bin/checkmodule:  policy configuration loaded
>  /usr/bin/checkmodule:  writing binary representation (version 10) to 
>  tmp/foo.mod
>  Creating targeted foo.pp policy package
>  rm tmp/foo.mod.fc tmp/foo.mod
>  
>  # semodule -i foo.pp
>  libsepol.print_missing_requirements: java's global requirements were
>  not 
>  met: type/attribute green_java_t (No such file or directory).
>  libsemanage.semanage_link_sandbox: Link packages failed (No such file
>  or 
>  directory).
>  semodule:  Failed! 
Again, this is because you named your module java and therefore it is
viewed as a replacement for the refpolicy java module, and thereby
removing the normal java policy definitions.

> You have new mail in /var/spool/mail/root
> 
> # sesearch -A -s green_java_t -t green_jar_t -c file
> Found 1 semantic av rules:
>     allow green_java_t file_type : file execmod ;
> 
> What am I missing?
> 
> Thank you & Best Regards,
> 
> Bill
> 
> P.S. I have subscribed to the refpolicy mailing list but I am still 
> waiting for my subscription request to get accepted.
> 
> On 05/26/2017 06:58 AM, Stephen Smalley wrote:
> > On Thu, 2017-05-25 at 14:20 -0700, Bill D wrote:
> > > Hello Stephen:
> > > 
> > > I tried it via RBAC/TE without success.
> > > 
> > > How to prevent a Linux user from reading/running a Java JAR file
> > > via
> > > RBAC/TE?
> > > 
> > > Here is what I did:
> > > 
> > > # id -u
> > > 0
> > > 
> > > # uname -a
> > > Linux rhel-billd 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Mar 21
> > > 12:19:18
> > > EDT 2017 x86_64 x86_64 x86_64 GNU/Linux
> > > 
> > > # cat /etc/redhat-release
> > > Red Hat Enterprise Linux Server release 6.9 (Santiago)
> > > 
> > > # setenforce 0
> > > 
> > > # getenforce
> > > Permissive
> > > 
> > > # cd green
> > > 
> > > # cat green_app.te
> > > policy_module(green_app, 0.0.1)
> > > type green_app_t;
> > > type green_app_exec_t;
> > > application_executable_file(green_app_exec_t)
> > > application_domain(green_app_t, green_app_exec_t)
> > > role green_r types green_app_t;
> > > require { type green_t; }
> > > domain_auto_trans(green_t, green_app_exec_t, green_app_t)
> > 
> > Note that most of this policy module is unnecessary/unused, because
> > you
> > aren't truly executing the jar files, so there is no domain
> > transition,
> > and hence neither green_app_t nor the rules generated by
> > application_domain() or domain_auto_trans() are ever
> > exercised.  The
> > definitions you have above are more suitable to an executable
> > program,
> > not a data file, and at the end of the day, a .jar file is really
> > just
> > data.  I would just declare green_jar_t and make it a file_type()
> > only.
> > 
> > > # cat green_user.te
> > > policy_module(green, 0.0.1)
> > > role green_r;
> > > userdom_unpriv_user_template(green)
> > > gen_user(green_u, user, green_r, s0, s0)
> > > 
> > > # cat green_app.fc
> > > /usr/local/soup/bin/green.jar --
> > > gen_context(system_u:object_r:green_app_exec_t, s0)
> > > 
> > > # cp /etc/selinux/targeted/contexts/users/user_u
> > > /etc/selinux/targeted/contexts/users/green_u
> > > 
> > > # sed -i 's/user/green/g'
> > > /etc/selinux/targeted/contexts/users/green_u
> > > 
> > > # cat /etc/selinux/targeted/contexts/users/green_u
> > > system_r:local_login_t:s0    green_r:green_t:s0
> > > system_r:remote_login_t:s0    green_r:green_t:s0
> > > system_r:sshd_t:s0        green_r:green_t:s0
> > > system_r:crond_t:s0        green_r:green_t:s0
> > > system_r:xdm_t:s0        green_r:green_t:s0
> > > green_r:green_su_t:s0        green_r:green_t:s0
> > > green_r:green_sudo_t:s0        green_r:green_t:s0
> > > system_r:initrc_su_t:s0        green_r:green_t:s0
> > > green_r:green_t:s0        green_r:green_t:s0
> > > 
> > > # make -f /usr/share/selinux/devel/Makefile
> > > Compiling targeted green_app module
> > > /usr/bin/checkmodule:  loading policy configuration from
> > > tmp/green_app.tmp
> > > /usr/bin/checkmodule:  policy configuration loaded
> > > /usr/bin/checkmodule:  writing binary representation (version 10)
> > > to
> > > tmp/green_app.mod
> > > Creating targeted green_app.pp policy package
> > > Compiling targeted green_user module
> > > /usr/bin/checkmodule:  loading policy configuration from
> > > tmp/green_user.tmp
> > > /usr/bin/checkmodule:  policy configuration loaded
> > > /usr/bin/checkmodule:  writing binary representation (version 10)
> > > to
> > > tmp/green_user.mod
> > > Creating targeted green_user.pp policy package
> > > rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod
> > > tmp/green_app.mod.fc
> > > 
> > > # cat green_app.if
> > > ## <summary></summary>
> > > 
> > > # cat green_user.if
> > > ## <summary></summary>
> > > 
> > > # cat green_user.fc
> > > 
> > > # semodule -i green_user.pp green_app.pp
> > > 
> > > # useradd -Z green_u mary
> > > 
> > > # passwd mary
> > > Changing password for user mary.
> > > New password:
> > > Retype new password:
> > > passwd: all authentication tokens updated successfully.
> > > 
> > > # restorecon -v /usr/local/soup/bin/green.jar
> > > restorecon reset /usr/local/soup/bin/green.jar context
> > > system_u:object_r:bin_t:s0->system_u:object_r:green_app_exec_t:s0
> > > 
> > > # ls -Z /usr/local/soup/bin/green.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:green_app_exec_t:SystemLow
> > > /usr/local/soup/bin/green.jar
> > > 
> > > # cd ../red
> > > 
> > > # cat red_app.te
> > > policy_module(red_app, 0.0.1)
> > > type red_app_t;
> > > type red_app_exec_t;
> > > application_executable_file(red_app_exec_t)
> > > application_domain(red_app_t, red_app_exec_t)
> > > role red_r types red_app_t;
> > > require { type red_t; }
> > > domain_auto_trans(red_t, red_app_exec_t, red_app_t)
> > 
> > Same as for green_app.te above.
> > 
> > > # cat red_user.te
> > > policy_module(red, 0.0.1)
> > > role red_r;
> > > userdom_unpriv_user_template(red)
> > > gen_user(red_u, user, red_r, s0, s0)
> > > 
> > > # cat red_app.fc
> > > /usr/local/soup/bin/red.jar --
> > > gen_context(system_u:object_r:red_app_exec_t, s0)
> > > 
> > > # cp /etc/selinux/targeted/contexts/users/user_u
> > > /etc/selinux/targeted/contexts/users/red_u
> > > 
> > > # sed -i 's/user/red/g'
> > > /etc/selinux/targeted/contexts/users/red_u
> > > 
> > > # cat /etc/selinux/targeted/contexts/users/red_u
> > > system_r:local_login_t:s0    red_r:red_t:s0
> > > system_r:remote_login_t:s0    red_r:red_t:s0
> > > system_r:sshd_t:s0        red_r:red_t:s0
> > > system_r:crond_t:s0        red_r:red_t:s0
> > > system_r:xdm_t:s0        red_r:red_t:s0
> > > red_r:red_su_t:s0        red_r:red_t:s0
> > > red_r:red_sudo_t:s0        red_r:red_t:s0
> > > system_r:initrc_su_t:s0        red_r:red_t:s0
> > > red_r:red_t:s0        red_r:red_t:s0
> > > 
> > > # make -f /usr/share/selinux/devel/Makefile
> > > Compiling targeted red_app module
> > > /usr/bin/checkmodule:  loading policy configuration from
> > > tmp/red_app.tmp
> > > /usr/bin/checkmodule:  policy configuration loaded
> > > /usr/bin/checkmodule:  writing binary representation (version 10)
> > > to
> > > tmp/red_app.mod
> > > Creating targeted red_app.pp policy package
> > > Compiling targeted red_user module
> > > /usr/bin/checkmodule:  loading policy configuration from
> > > tmp/red_user.tmp
> > > /usr/bin/checkmodule:  policy configuration loaded
> > > /usr/bin/checkmodule:  writing binary representation (version 10)
> > > to
> > > tmp/red_user.mod
> > > Creating targeted red_user.pp policy package
> > > rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod
> > > tmp/red_app.mod.fc
> > > 
> > > # cat red_app.if
> > > ## <summary></summary>
> > > 
> > > # cat red_user.if
> > > ## <summary></summary>
> > > 
> > > # cat red_user.fc
> > > 
> > > # semodule -i red_user.pp red_app.pp
> > > 
> > > # useradd -Z red_u jack
> > > 
> > > # passwd jack
> > > Changing password for user jack.
> > > New password:
> > > Retype new password:
> > > passwd: all authentication tokens updated successfully.
> > > 
> > > # restorecon -v /usr/local/soup/bin/red.jar
> > > restorecon reset /usr/local/soup/bin/red.jar context
> > > system_u:object_r:bin_t:s0->system_u:object_r:red_app_exec_t:s0
> > > 
> > > # ls -Z /usr/local/soup/bin/red.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:red_app_exec_t:SystemLow
> > > /usr/local/soup/bin/red.jar
> > > 
> > > # setenforce 1
> > > 
> > > # getenforce
> > > Enforcing
> > > 
> > > Now logon as Linux user mary and notice that it can read/run
> > > red.jar
> > > which is NOT expected:
> > > 
> > > $ whoami
> > > mary
> > > 
> > > $ id -Z
> > > green_u:green_r:green_t:SystemLow
> > > 
> > > $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:green_app_exec_t:SystemLow
> > > /usr/local/soup/bin/green.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:red_app_exec_t:SystemLow
> > > /usr/local/soup/bin/red.jar
> > > 
> > > $ getenforce
> > > Enforcing
> > > 
> > > $ java -jar /usr/local/soup/bin/green.jar
> > > Hello from the green application
> > > 
> > > $ java -jar /usr/local/soup/bin/red.jar
> > > Hello from the red application
> > 
> > So at this point you can query the policy to understand what is
> > allowing this access:
> > yum install setools-console
> > sesearch -A -s green_t -t red_app_exec_t -c file
> > Found 1 semantic av rules:
> >     allow green_usertype application_exec_type : file { ioctl read
> > getattr lock execute execute_no_trans open } ;
> > 
> > And if we look at the refpolicy headers, we see that all user
> > domains
> > are allowed to read/execute all applications:
> > # grep -n application_exec
> > /usr/share/selinux/devel/include/system/userdomain.if
> > 72:	application_exec_all($1_usertype)
> > 
> > So by declaring the types as application_executable_file(), you
> > allowed
> > all user domains to read/execute them. If you only make them
> > file_type(), then they won't be immediately readable/executable by
> > all
> > user domains.
> > 
> > Depending on your goals, you may find that refpolicy's
> > userdom_unpriv_user_template() is too liberal in what it allows and
> > you
> > may want to define your own, more minimalist set.
> > 
> > Questions/comments about refpolicy interfaces and implementation
> > should
> > go to the refpolicy mailing list,
> > http://oss.tresys.com/mailman/listinfo/refpolicy
> > 
> > > The same situation happens with user jack as follows:
> > > 
> > > $ whoami
> > > jack
> > > 
> > > $ id -Z
> > > red_u:red_r:red_t:SystemLow
> > > 
> > > $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:green_app_exec_t:SystemLow
> > > /usr/local/soup/bin/green.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:red_app_exec_t:SystemLow
> > > /usr/local/soup/bin/red.jar
> > > 
> > > $ getenforce
> > > Enforcing
> > > 
> > > $ java -jar /usr/local/soup/bin/green.jar
> > > Hello from the green application
> > > 
> > > $ java -jar /usr/local/soup/bin/red.jar
> > > Hello from the red application
> > > 
> > > How to prevent mary from reading/running red.jar and jack from
> > > running/running green.jar?
> > > 
> > > ===================================
> > > 
> > > Following is how to create the JAR files:
> > > 
> > > $ whoami
> > > admin
> > > 
> > > $ id -Z
> > > unconfined_u:unconfined_r:unconfined_t:SystemLow-SystemHigh
> > > 
> > > $ cat Green.java
> > > public class Green {
> > >       public static void main(String[] args) {
> > >           System.out.println("Hello from the green
application");
> > >       }
> > > }
> > > 
> > > $ javac Green.java
> > > 
> > > $ cat manifest.txt
> > > Main-Class:
> > > 
> > > $ jar cvfe green.jar Green Green.class
> > > added manifest
> > > adding: Green.class(in = 436) (out= 301)(deflated 30%)
> > > 
> > > $ ls -Z green.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:green_app_exec_t:SystemLow
> > > green.jar
> > > 
> > > $ cat Red.java
> > > public class Red {
> > >       public static void main(String[] args) {
> > >           System.out.println("Hello from the red application");
> > >       }
> > > }
> > > 
> > > $ javac Red.java
> > > 
> > > $ cat manifest.txt
> > > Main-Class:
> > > 
> > > $ jar cvfe red.jar Red Red.class
> > > added manifest
> > > adding: Red.class(in = 430) (out= 301)(deflated 30%)
> > > 
> > > $ ls -Z red.jar
> > > -rwxr-xr-x. admin admin
> > > system_u:object_r:red_app_exec_t:SystemLow
> > > red.jar
> > > 
> > > Best Regards,
> > > 
> > > Bill
> > > On 05/24/2017 02:19 PM, Bill D wrote:
> > > 
> > > > On 05/24/2017 01:36 PM, Stephen Smalley wrote:
> > > > 
> > > > > On Tue, 2017-05-23 at 16:51 -0700, Bill D wrote:
> > > > > > Greetings:
> > > > > > 
> > > > > > I have been trying to figure out how to control the
> > > > > > execution
> > > > > > of
> > > > > > Java
> > > > > > JAR files with SELinux RBAC.
> > > > > > 
> > > > > > I have two Linux users named joe and mary and two Java JAR
> > > > > > files
> > > > > > named
> > > > > > jack.jar and mary.jar.
> > > > > > 
> > > > > > Here is how jack executes jack.jar: java -jar jack.jar
> > > > > > 
> > > > > > Here is how mary executes mary.jar: java -jar mary.jar
> > > > > 
> > > > > So they aren't actually executing those files; they are both
> > > > > executing
> > > > > java, which in turn is reading those files and interpreting
> > > > > the
> > > > > contents.
> > > > 
> > > > Correct.
> > > > 
> > > > 
> > > > > > I would like SELinux RBAC to prevent jack from executing
> > > > > > mary.jar
> > > > > > and
> > > > > > prevent mary from executing jack.jar.
> > > > > > 
> > > > > > How to configure SELinux RBAC to make that happen?
> > > > > > 
> > > > > > I have tried various approaches without success.  I have
> > > > > > also
> > > > > > tried
> > > > > > the
> > > > > > steps in http://forums.fedoraforum.org/archive/index.php/t-
> > > > > > 2229
> > > > > > 38.htm
> > > > > > l
> > > > > > without success.
> > > > > > 
> > > > > > I would greatly appreciate any hints.
> > > > > 
> > > > > Perhaps you could describe what you tried in more detail, and
> > > > > how
> > > > > it
> > > > > failed.  The thing to remember is that for your scenario
> > > > > above,
> > > > > you
> > > > > need to control read permission, not execute permission.  You
> > > > > can
> > > > > either do this via RBAC/TE (in which case you need separate
> > > > > SELinux
> > > > > users, roles, and domains for jack and mary, and separate
> > > > > types
> > > > > for
> > > > > jack.jar and mary.jar), or via MCS/MLS (in which case you
> > > > > need to
> > > > > have
> > > > > jack and mary run in MCS constrained domains, authorize them
> > > > > for
> > > > > different categories, and assign those different categories
> > > > > to
> > > > > the .jar
> > > > > files).
> > > > 
> > > > Thank you for making me realize that the access control that I
> > > > need
> > > > is
> > > > indeed read, not execute.
> > > > 
> > > > I will try again via RBAC/TE and will provide details on what I
> > > > tried
> > > > if I still cannot get it to work.
> > > > 
> > > > > Perhaps the better question is what is it that you are really
> > > > > trying to
> > > > > achieve.  Merely controlling which jar files they can
> > > > > read/execute
> > > > > isn't terribly interesting; what prevents them from just re-
> > > > > creating or
> > > > > downloading the other .jar file themselves?
> > > > 
> > > > I am trying to implement the least privilege concept on a
> > > > particular
> > > > system.  At this point it is fine if the user copies the other
> > > > JAR
> > > > file to other systems since it will not run as expected on that
> > > > other
> > > > system.  But this may become a requirement later...
> > > > 
> > > > Thanks!
> > > > 
> > > > Bill
> > > > 
> > > > > _______________________________________________
> > > > > selinux mailing list -- selinux(a)lists.fedoraproject.org
> > > > > To unsubscribe send an email to selinux-leave(a)lists.fedorapro
> > > > > ject
> > > > > .org

[Bill D]

Hello Stephen:

It works now as per your suggestions.  Thank you!

Here is the complete solution in case other people would like to know 
how to make it work:

# setenforce 0

# getenforce
Permissive

# cp /etc/selinux/targeted/contexts/users/user_u 
/etc/selinux/targeted/contexts/users/red_u

# cp /etc/selinux/targeted/contexts/users/user_u 
/etc/selinux/targeted/contexts/users/green_u

# sed -i 's/user/red/g' /etc/selinux/targeted/contexts/users/red_u

# sed -i 's/user/green/g' /etc/selinux/targeted/contexts/users/green_u

# cd red

# cat red_user.te
policy_module(red, 0.0.1)
role red_r;
userdom_unpriv_user_template(red)
gen_user(red_u, user, red_r, s0, s0)

# cat red_app.te
policy_module(red_app, 0.0.1)
require {
     type red_java_t;
     type red_jar_t;
}
type red_jar_t;
files_type(red_jar_t)
allow red_java_t red_jar_t:file read_file_perms;

# cat red_app.fc
/usr/local/soup/bin/red.jar -- gen_context(system_u:object_r:red_jar_t, s0)

# make -f /usr/share/selinux/devel/Makefile clean
rm -fR tmp
rm -f *.pp

# make -f /usr/share/selinux/devel/Makefile
Compiling targeted red_app module
/usr/bin/checkmodule:  loading policy configuration from tmp/red_app.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/red_app.mod
Creating targeted red_app.pp policy package
Compiling targeted red_user module
/usr/bin/checkmodule:  loading policy configuration from tmp/red_user.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/red_user.mod
Creating targeted red_user.pp policy package
rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod tmp/red_app.mod.fc

# semodule -i red_user.pp red_app.pp

# restorecon -v /usr/local/soup/bin/red.jar
restorecon reset /usr/local/soup/bin/red.jar context 
unconfined_u:object_r:usr_t:s0->unconfined_u:object_r:red_jar_t:s0

# cd ..

# cd green

# cat green_user.te
policy_module(green, 0.0.1)
role green_r;
userdom_unpriv_user_template(green)
gen_user(green_u, user, green_r, s0, s0)

# cat green_app.te
policy_module(green_app, 0.0.1)
require {
     type green_java_t;
     type green_jar_t;
}
type green_jar_t;
files_type(green_jar_t)
allow green_java_t green_jar_t:file read_file_perms;

# cat green_app.fc
/usr/local/soup/bin/green.jar -- 
gen_context(system_u:object_r:green_jar_t, s0)

# make -f /usr/share/selinux/devel/Makefile clean
rm -fR tmp
rm -f *.pp

# make -f /usr/share/selinux/devel/Makefile
Compiling targeted green_app module
/usr/bin/checkmodule:  loading policy configuration from tmp/green_app.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/green_app.mod
Creating targeted green_app.pp policy package
Compiling targeted green_user module
/usr/bin/checkmodule:  loading policy configuration from tmp/green_user.tmp
/usr/bin/checkmodule:  policy configuration loaded
/usr/bin/checkmodule:  writing binary representation (version 10) to 
tmp/green_user.mod
Creating targeted green_user.pp policy package
rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod 
tmp/green_app.mod.fc

# semodule -i green_user.pp green_app.pp

# restorecon -v /usr/local/soup/bin/green.jar
restorecon reset /usr/local/soup/bin/green.jar context 
unconfined_u:object_r:usr_t:s0->unconfined_u:object_r:green_jar_t:s0

# chmod -R 755 /usr/local/soup

# chown -R admin:admin /usr/local/soup

# chcon -u system_u /usr/local/soup/bin/*.jar

# ls -Z /usr/local/soup/bin/*.jar
-rwxr-xr-x. admin admin system_u:object_r:green_jar_t:s0 
/usr/local/soup/bin/green.jar
-rwxr-xr-x. admin admin system_u:object_r:red_jar_t:s0 
/usr/local/soup/bin/red.jar

# useradd -Z green_u mary

# useradd -Z red_u jack

# passwd mary
Changing password for user mary.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# passwd jack
Changing password for user jack.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

# setenforce 1

# getenforce
Enforcing

Now verify that green_r has green_java_t assigned and that red_r has
red_java_t assigned

# seinfo -rgreen_r -x | grep java
          green_java_t
# seinfo -rred_r -x | grep java
          red_java_t


Verify that green_java_t and red_java_t can execute the java executable:

# ls -Z /usr/java/jdk1.8.0_25/bin/java
-rwxr-xr-x. root root system_u:object_r:java_exec_t:s0 
/usr/java/jdk1.8.0_25/bin/java

# sesearch -A -s green_java_t -t java_exec_t -c file
Found 3 semantic av rules:
    allow green_usertype application_exec_type : file { ioctl read 
getattr lock execute execute_no_trans open } ;
    allow green_java_t java_exec_t : file { ioctl read getattr lock 
execute entrypoint open } ;
    allow green_java_t file_type : file execmod ;

# sesearch -A -s red_java_t -t java_exec_t -c file
Found 3 semantic av rules:
    allow red_java_t java_exec_t : file { ioctl read getattr lock 
execute entrypoint open } ;
    allow red_usertype application_exec_type : file { ioctl read getattr 
lock execute execute_no_trans open } ;
    allow red_java_t file_type : file execmod ;

Now login as Linux user mary and notice that access control works as 
expected:

$ whoami
mary

$ id -Z
green_u:green_r:green_t:s0

$ java -jar /usr/local/soup/bin/green.jar
Hello from the green application

$ java -jar /usr/local/soup/bin/red.jar
Error: Unable to access jarfile /usr/local/soup/bin/red.jar

Now login as Linux user jack and notice that access control works as 
expected:

$ whoami
jack

$ id -Z
red_u:red_r:red_t:s0

$ java -jar /usr/local/soup/bin/red.jar
Hello from the red application

$ java -jar /usr/local/soup/bin/green.jar
Error: Unable to access jarfile /usr/local/soup/bin/green.jar

Regards,

Bill

On 05/30/2017 06:32 AM, Stephen Smalley wrote:
>  On Mon, 2017-05-29 at 12:43 -0700, Bill Durant wrote:
> > Hello Stephen:
> >
> > I went ahead and tried to just declare green_jar_t and made it a
> > file
> > type as you have suggested but I think I may have something wrong
> > with
> > the TE policy that I created.  Here is what I did and the error that
> > I
> > am getting:
> >
> > # uname -a
> > Linux es300h 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Apr 11 17:13:24
> > UTC
> > 2017 x86_64 x86_64 x86_64 GNU/Linux
> >
> > # cat /etc/redhat-release
> > CentOS release 6.9 (Final)
> >
> > # whoami
> > root
> >
> > # setenforce 0
> >
> > # cp /etc/selinux/targeted/contexts/users/user_u
> > /etc/selinux/targeted/contexts/users/red_u
> > # cp /etc/selinux/targeted/contexts/users/user_u
> > /etc/selinux/targeted/contexts/users/green_u
> > # sed -i 's/user/red/g' /etc/selinux/targeted/contexts/users/red_u
> > # sed -i 's/user/green/g'
> > /etc/selinux/targeted/contexts/users/green_u
> >
> > # cd red
> >
> > # cat red_user.te
> > policy_module(red, 0.0.1)
> > role red_r;
> > userdom_unpriv_user_template(red)
> > gen_user(red_u, user, red_r, s0, s0)
> >
> > # cat red_app.te
> > policy_module(red_app, 0.0.1)
> > type red_jar_t;
> > files_type(red_jar_t)
> > role red_r types red_jar_t;
>  You don't need the above role statement, because red_jar_t is only used
>  as a file type (with object_r), never as a process type/domain.
>
> > # cat red_app.fc
> > /usr/local/soup/bin/red.jar --
> > gen_context(system_u:object_r:red_jar_t, s0)
> >
> > # make -f /usr/share/selinux/devel/Makefile
> > Compiling targeted red_app module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/red_app.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/red_app.mod
> > Creating targeted red_app.pp policy package
> > Compiling targeted red_user module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/red_user.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/red_user.mod
> > Creating targeted red_user.pp policy package
> > rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod
> > tmp/red_app.mod.fc
> >
> > # semodule -i red_user.pp red_app.pp
> >
> > # restorecon -v /usr/local/soup/bin/red.jar
> > restorecon reset /usr/local/soup/bin/red.jar context
> > system_u:object_r:bin_t:s0->system_u:object_r:red_jar_t:s0
> >
> > # ls -Z /usr/local/soup/bin/red.jar
> > -rwxr-xr-x. root root system_u:object_r:red_jar_t:s0
> > /usr/local/soup/bin/red.jar
> >
> > # cd ../green
> >
> > # cat green_user.te
> > policy_module(green, 0.0.1)
> > role green_r;
> > userdom_unpriv_user_template(green)
> > gen_user(green_u, user, green_r, s0, s0)
> >
> > # cat green_app.te
> > policy_module(green_app, 0.0.1)
> > type green_jar_t;
> > files_type(green_jar_t)
> > role green_r types green_jar_t;
>  Likewise for the above role statement.
>
> > # cat green_app.fc
> > /usr/local/soup/bin/green.jar --
> > gen_context(system_u:object_r:green_jar_t, s0)
> >
> > # make -f /usr/share/selinux/devel/Makefile
> > Compiling targeted green_app module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/green_app.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/green_app.mod
> > Creating targeted green_app.pp policy package
> > Compiling targeted green_user module
> > /usr/bin/checkmodule:  loading policy configuration from
> > tmp/green_user.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/green_user.mod
> > Creating targeted green_user.pp policy package
> > rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod
> > tmp/green_app.mod.fc
> >
> > # semodule -i green_user.pp green_app.pp
> >
> > # restorecon -v /usr/local/soup/bin/green.jar
> > restorecon reset /usr/local/soup/bin/green.jar context
> > system_u:object_r:bin_t:s0->system_u:object_r:green_jar_t:s0
> >
> > # ls -Z /usr/local/soup/bin/green.jar
> > -rwxr-xr-x. root root system_u:object_r:green_jar_t:s0
> > /usr/local/soup/bin/green.jar
> >
> > # useradd -Z green_u mary
> >
> > # useradd -Z red_u jack
> >
> > # passwd mary
> > Changing password for user mary.
> > New password:
> > Retype new password:
> > passwd: all authentication tokens updated successfully.
> >
> > # passwd jack
> > Changing password for user jack.
> > New password:
> > Retype new password:
> > passwd: all authentication tokens updated successfully.
> >
> > # setenforce 1
> >
> > Now login as Linux user mary and notice that java is unable to read
> > the
> > JAR file which is NOT expected:
> >
> > $ whoami
> > mary
> >
> > $ java -jar /usr/local/soup/bin/green.jar
> > Error: Unable to access jarfile /usr/local/soup/bin/green.jar
> >
> > Now let's try to fix that with audit2allow:
> >
> >   From /var/log/audit/audit.log:
> > ...
> > ...
> > type=AVC msg=audit(1496085668.816:22282): avc:  denied  { read }
> > for
> > pid=10657 comm="java" name="green.jar" dev=dm-0 ino=934010
> > scontext=green_u:green_r:green_java_t:s0
> > tcontext=system_u:object_r:green_jar_t:s0 tclass=file
> >
> > ...
> > ...
> >
> > # grep java /var/log/audit/audit.log | audit2allow -m java > foo.te
> >
> > # cat foo.te
> >
> > module java 1.0;
> >
> > require {
> >       type user_tmp_t;
> >       type green_java_t;
> >       type vmblock_t;
> >       type sshd_t;
> >       type sysctl_fs_t;
> >       type usr_t;
> >       type green_jar_t;
> >       class dir { getattr search };
> >       class file { read execute append };
> > }
> >
> > #============= green_java_t ==============
> > allow green_java_t green_jar_t:file read;
> >
> > #============= sshd_t ==============
> > allow sshd_t sysctl_fs_t:dir search;
> > allow sshd_t user_tmp_t:file execute;
> > allow sshd_t usr_t:file append;
> > allow sshd_t vmblock_t:dir getattr;
>  There are several problems with this policy module:
>  1) You named it "java", and therefore it will replace the refpolicy
>  java policy module when you try to install it (that's why you get the
>  error below, because you are removing the java module definitions when
>  you insert this one).
>
>  2) You included several unrelated requires and allow rules above that
>  have nothing to do with this denial.  You want to be more selective in
>  what you select with ausearch or remove the extraneous ones afterward.
>
>  3) You will need more than just read permission ultimately (e.g. open,
>  possibly others).  Better to use a refpolicy macro instead.
>
>  So, for example, I would write this as:
>  policy_module(greenjava, 1.0)
>  require {
>  	type green_java_t;
>  	type green_jar_t;
>  }
>  allow green_java_t green_jar_t:file read_file_perms;
>
>  And probably I would just insert the above requires and allow rules
>  into your already existing green_app.te module instead of creating a
>  separate one.
>
> > # make -f /usr/share/selinux/devel/Makefile
> > Compiling targeted foo module
> > /usr/bin/checkmodule:  loading policy configuration from tmp/foo.tmp
> > /usr/bin/checkmodule:  policy configuration loaded
> > /usr/bin/checkmodule:  writing binary representation (version 10) to
> > tmp/foo.mod
> > Creating targeted foo.pp policy package
> > rm tmp/foo.mod.fc tmp/foo.mod
> >
> > # semodule -i foo.pp
> > libsepol.print_missing_requirements: java's global requirements were
> > not
> > met: type/attribute green_java_t (No such file or directory).
> > libsemanage.semanage_link_sandbox: Link packages failed (No such file
> > or
> > directory).
> > semodule:  Failed!
>  Again, this is because you named your module java and therefore it is
>  viewed as a replacement for the refpolicy java module, and thereby
>  removing the normal java policy definitions.
>
> > You have new mail in /var/spool/mail/root
> >
> > # sesearch -A -s green_java_t -t green_jar_t -c file
> > Found 1 semantic av rules:
> >      allow green_java_t file_type : file execmod ;
> >
> > What am I missing?
> >
> > Thank you & Best Regards,
> >
> > Bill
> >
> > P.S. I have subscribed to the refpolicy mailing list but I am still
> > waiting for my subscription request to get accepted.
> >
> > On 05/26/2017 06:58 AM, Stephen Smalley wrote:
> >> On Thu, 2017-05-25 at 14:20 -0700, Bill D wrote:
> >>> Hello Stephen:
> >>>
> >>> I tried it via RBAC/TE without success.
> >>>
> >>> How to prevent a Linux user from reading/running a Java JAR file
> >>> via
> >>> RBAC/TE?
> >>>
> >>> Here is what I did:
> >>>
> >>> # id -u
> >>> 0
> >>>
> >>> # uname -a
> >>> Linux rhel-billd 2.6.32-696.1.1.el6.x86_64 #1 SMP Tue Mar 21
> >>> 12:19:18
> >>> EDT 2017 x86_64 x86_64 x86_64 GNU/Linux
> >>>
> >>> # cat /etc/redhat-release
> >>> Red Hat Enterprise Linux Server release 6.9 (Santiago)
> >>>
> >>> # setenforce 0
> >>>
> >>> # getenforce
> >>> Permissive
> >>>
> >>> # cd green
> >>>
> >>> # cat green_app.te
> >>> policy_module(green_app, 0.0.1)
> >>> type green_app_t;
> >>> type green_app_exec_t;
> >>> application_executable_file(green_app_exec_t)
> >>> application_domain(green_app_t, green_app_exec_t)
> >>> role green_r types green_app_t;
> >>> require { type green_t; }
> >>> domain_auto_trans(green_t, green_app_exec_t, green_app_t)
> >> Note that most of this policy module is unnecessary/unused, because
> >> you
> >> aren't truly executing the jar files, so there is no domain
> >> transition,
> >> and hence neither green_app_t nor the rules generated by
> >> application_domain() or domain_auto_trans() are ever
> >> exercised.  The
> >> definitions you have above are more suitable to an executable
> >> program,
> >> not a data file, and at the end of the day, a .jar file is really
> >> just
> >> data.  I would just declare green_jar_t and make it a file_type()
> >> only.
> >>
> >>> # cat green_user.te
> >>> policy_module(green, 0.0.1)
> >>> role green_r;
> >>> userdom_unpriv_user_template(green)
> >>> gen_user(green_u, user, green_r, s0, s0)
> >>>
> >>> # cat green_app.fc
> >>> /usr/local/soup/bin/green.jar --
> >>> gen_context(system_u:object_r:green_app_exec_t, s0)
> >>>
> >>> # cp /etc/selinux/targeted/contexts/users/user_u
> >>> /etc/selinux/targeted/contexts/users/green_u
> >>>
> >>> # sed -i 's/user/green/g'
> >>> /etc/selinux/targeted/contexts/users/green_u
> >>>
> >>> # cat /etc/selinux/targeted/contexts/users/green_u
> >>> system_r:local_login_t:s0    green_r:green_t:s0
> >>> system_r:remote_login_t:s0    green_r:green_t:s0
> >>> system_r:sshd_t:s0        green_r:green_t:s0
> >>> system_r:crond_t:s0        green_r:green_t:s0
> >>> system_r:xdm_t:s0        green_r:green_t:s0
> >>> green_r:green_su_t:s0        green_r:green_t:s0
> >>> green_r:green_sudo_t:s0        green_r:green_t:s0
> >>> system_r:initrc_su_t:s0        green_r:green_t:s0
> >>> green_r:green_t:s0        green_r:green_t:s0
> >>>
> >>> # make -f /usr/share/selinux/devel/Makefile
> >>> Compiling targeted green_app module
> >>> /usr/bin/checkmodule:  loading policy configuration from
> >>> tmp/green_app.tmp
> >>> /usr/bin/checkmodule:  policy configuration loaded
> >>> /usr/bin/checkmodule:  writing binary representation (version 10)
> >>> to
> >>> tmp/green_app.mod
> >>> Creating targeted green_app.pp policy package
> >>> Compiling targeted green_user module
> >>> /usr/bin/checkmodule:  loading policy configuration from
> >>> tmp/green_user.tmp
> >>> /usr/bin/checkmodule:  policy configuration loaded
> >>> /usr/bin/checkmodule:  writing binary representation (version 10)
> >>> to
> >>> tmp/green_user.mod
> >>> Creating targeted green_user.pp policy package
> >>> rm tmp/green_user.mod.fc tmp/green_app.mod tmp/green_user.mod
> >>> tmp/green_app.mod.fc
> >>>
> >>> # cat green_app.if
> >>> ## <summary></summary>
> >>>
> >>> # cat green_user.if
> >>> ## <summary></summary>
> >>>
> >>> # cat green_user.fc
> >>>
> >>> # semodule -i green_user.pp green_app.pp
> >>>
> >>> # useradd -Z green_u mary
> >>>
> >>> # passwd mary
> >>> Changing password for user mary.
> >>> New password:
> >>> Retype new password:
> >>> passwd: all authentication tokens updated successfully.
> >>>
> >>> # restorecon -v /usr/local/soup/bin/green.jar
> >>> restorecon reset /usr/local/soup/bin/green.jar context
> >>> system_u:object_r:bin_t:s0->system_u:object_r:green_app_exec_t:s0
> >>>
> >>> # ls -Z /usr/local/soup/bin/green.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:green_app_exec_t:SystemLow
> >>> /usr/local/soup/bin/green.jar
> >>>
> >>> # cd ../red
> >>>
> >>> # cat red_app.te
> >>> policy_module(red_app, 0.0.1)
> >>> type red_app_t;
> >>> type red_app_exec_t;
> >>> application_executable_file(red_app_exec_t)
> >>> application_domain(red_app_t, red_app_exec_t)
> >>> role red_r types red_app_t;
> >>> require { type red_t; }
> >>> domain_auto_trans(red_t, red_app_exec_t, red_app_t)
> >> Same as for green_app.te above.
> >>
> >>> # cat red_user.te
> >>> policy_module(red, 0.0.1)
> >>> role red_r;
> >>> userdom_unpriv_user_template(red)
> >>> gen_user(red_u, user, red_r, s0, s0)
> >>>
> >>> # cat red_app.fc
> >>> /usr/local/soup/bin/red.jar --
> >>> gen_context(system_u:object_r:red_app_exec_t, s0)
> >>>
> >>> # cp /etc/selinux/targeted/contexts/users/user_u
> >>> /etc/selinux/targeted/contexts/users/red_u
> >>>
> >>> # sed -i 's/user/red/g'
> >>> /etc/selinux/targeted/contexts/users/red_u
> >>>
> >>> # cat /etc/selinux/targeted/contexts/users/red_u
> >>> system_r:local_login_t:s0    red_r:red_t:s0
> >>> system_r:remote_login_t:s0    red_r:red_t:s0
> >>> system_r:sshd_t:s0        red_r:red_t:s0
> >>> system_r:crond_t:s0        red_r:red_t:s0
> >>> system_r:xdm_t:s0        red_r:red_t:s0
> >>> red_r:red_su_t:s0        red_r:red_t:s0
> >>> red_r:red_sudo_t:s0        red_r:red_t:s0
> >>> system_r:initrc_su_t:s0        red_r:red_t:s0
> >>> red_r:red_t:s0        red_r:red_t:s0
> >>>
> >>> # make -f /usr/share/selinux/devel/Makefile
> >>> Compiling targeted red_app module
> >>> /usr/bin/checkmodule:  loading policy configuration from
> >>> tmp/red_app.tmp
> >>> /usr/bin/checkmodule:  policy configuration loaded
> >>> /usr/bin/checkmodule:  writing binary representation (version 10)
> >>> to
> >>> tmp/red_app.mod
> >>> Creating targeted red_app.pp policy package
> >>> Compiling targeted red_user module
> >>> /usr/bin/checkmodule:  loading policy configuration from
> >>> tmp/red_user.tmp
> >>> /usr/bin/checkmodule:  policy configuration loaded
> >>> /usr/bin/checkmodule:  writing binary representation (version 10)
> >>> to
> >>> tmp/red_user.mod
> >>> Creating targeted red_user.pp policy package
> >>> rm tmp/red_user.mod tmp/red_user.mod.fc tmp/red_app.mod
> >>> tmp/red_app.mod.fc
> >>>
> >>> # cat red_app.if
> >>> ## <summary></summary>
> >>>
> >>> # cat red_user.if
> >>> ## <summary></summary>
> >>>
> >>> # cat red_user.fc
> >>>
> >>> # semodule -i red_user.pp red_app.pp
> >>>
> >>> # useradd -Z red_u jack
> >>>
> >>> # passwd jack
> >>> Changing password for user jack.
> >>> New password:
> >>> Retype new password:
> >>> passwd: all authentication tokens updated successfully.
> >>>
> >>> # restorecon -v /usr/local/soup/bin/red.jar
> >>> restorecon reset /usr/local/soup/bin/red.jar context
> >>> system_u:object_r:bin_t:s0->system_u:object_r:red_app_exec_t:s0
> >>>
> >>> # ls -Z /usr/local/soup/bin/red.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:red_app_exec_t:SystemLow
> >>> /usr/local/soup/bin/red.jar
> >>>
> >>> # setenforce 1
> >>>
> >>> # getenforce
> >>> Enforcing
> >>>
> >>> Now logon as Linux user mary and notice that it can read/run
> >>> red.jar
> >>> which is NOT expected:
> >>>
> >>> $ whoami
> >>> mary
> >>>
> >>> $ id -Z
> >>> green_u:green_r:green_t:SystemLow
> >>>
> >>> $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:green_app_exec_t:SystemLow
> >>> /usr/local/soup/bin/green.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:red_app_exec_t:SystemLow
> >>> /usr/local/soup/bin/red.jar
> >>>
> >>> $ getenforce
> >>> Enforcing
> >>>
> >>> $ java -jar /usr/local/soup/bin/green.jar
> >>> Hello from the green application
> >>>
> >>> $ java -jar /usr/local/soup/bin/red.jar
> >>> Hello from the red application
> >> So at this point you can query the policy to understand what is
> >> allowing this access:
> >> yum install setools-console
> >> sesearch -A -s green_t -t red_app_exec_t -c file
> >> Found 1 semantic av rules:
> >>      allow green_usertype application_exec_type : file { ioctl read
> >> getattr lock execute execute_no_trans open } ;
> >>
> >> And if we look at the refpolicy headers, we see that all user
> >> domains
> >> are allowed to read/execute all applications:
> >> # grep -n application_exec
> >> /usr/share/selinux/devel/include/system/userdomain.if
> >> 72:	application_exec_all($1_usertype)
> >>
> >> So by declaring the types as application_executable_file(), you
> >> allowed
> >> all user domains to read/execute them. If you only make them
> >> file_type(), then they won't be immediately readable/executable by
> >> all
> >> user domains.
> >>
> >> Depending on your goals, you may find that refpolicy's
> >> userdom_unpriv_user_template() is too liberal in what it allows and
> >> you
> >> may want to define your own, more minimalist set.
> >>
> >> Questions/comments about refpolicy interfaces and implementation
> >> should
> >> go to the refpolicy mailing list,
> >> http://oss.tresys.com/mailman/listinfo/refpolicy
> >>
> >>> The same situation happens with user jack as follows:
> >>>
> >>> $ whoami
> >>> jack
> >>>
> >>> $ id -Z
> >>> red_u:red_r:red_t:SystemLow
> >>>
> >>> $ ls -Z /usr/local/soup/bin/green.jar /usr/local/soup/bin/red.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:green_app_exec_t:SystemLow
> >>> /usr/local/soup/bin/green.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:red_app_exec_t:SystemLow
> >>> /usr/local/soup/bin/red.jar
> >>>
> >>> $ getenforce
> >>> Enforcing
> >>>
> >>> $ java -jar /usr/local/soup/bin/green.jar
> >>> Hello from the green application
> >>>
> >>> $ java -jar /usr/local/soup/bin/red.jar
> >>> Hello from the red application
> >>>
> >>> How to prevent mary from reading/running red.jar and jack from
> >>> running/running green.jar?
> >>>
> >>> ===================================
> >>>
> >>> Following is how to create the JAR files:
> >>>
> >>> $ whoami
> >>> admin
> >>>
> >>> $ id -Z
> >>> unconfined_u:unconfined_r:unconfined_t:SystemLow-SystemHigh
> >>>
> >>> $ cat Green.java
> >>> public class Green {
> >>>        public static void main(String[] args) {
> >>>            System.out.println("Hello from the green application");
> >>>        }
> >>> }
> >>>
> >>> $ javac Green.java
> >>>
> >>> $ cat manifest.txt
> >>> Main-Class:
> >>>
> >>> $ jar cvfe green.jar Green Green.class
> >>> added manifest
> >>> adding: Green.class(in = 436) (out= 301)(deflated 30%)
> >>>
> >>> $ ls -Z green.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:green_app_exec_t:SystemLow
> >>> green.jar
> >>>
> >>> $ cat Red.java
> >>> public class Red {
> >>>        public static void main(String[] args) {
> >>>            System.out.println("Hello from the red application");
> >>>        }
> >>> }
> >>>
> >>> $ javac Red.java
> >>>
> >>> $ cat manifest.txt
> >>> Main-Class:
> >>>
> >>> $ jar cvfe red.jar Red Red.class
> >>> added manifest
> >>> adding: Red.class(in = 430) (out= 301)(deflated 30%)
> >>>
> >>> $ ls -Z red.jar
> >>> -rwxr-xr-x. admin admin
> >>> system_u:object_r:red_app_exec_t:SystemLow
> >>> red.jar
> >>>
> >>> Best Regards,
> >>>
> >>> Bill
> >>> On 05/24/2017 02:19 PM, Bill D wrote:
> >>>
> >>>> On 05/24/2017 01:36 PM, Stephen Smalley wrote:
> >>>>
> >>>>> On Tue, 2017-05-23 at 16:51 -0700, Bill D wrote:
> >>>>>> Greetings:
> >>>>>>
> >>>>>> I have been trying to figure out how to control the
> >>>>>> execution
> >>>>>> of
> >>>>>> Java
> >>>>>> JAR files with SELinux RBAC.
> >>>>>>
> >>>>>> I have two Linux users named joe and mary and two Java JAR
> >>>>>> files
> >>>>>> named
> >>>>>> jack.jar and mary.jar.
> >>>>>>
> >>>>>> Here is how jack executes jack.jar: java -jar jack.jar
> >>>>>>
> >>>>>> Here is how mary executes mary.jar: java -jar mary.jar
> >>>>> So they aren't actually executing those files; they are both
> >>>>> executing
> >>>>> java, which in turn is reading those files and interpreting
> >>>>> the
> >>>>> contents.
> >>>> Correct.
> >>>>
> >>>>
> >>>>>> I would like SELinux RBAC to prevent jack from executing
> >>>>>> mary.jar
> >>>>>> and
> >>>>>> prevent mary from executing jack.jar.
> >>>>>>
> >>>>>> How to configure SELinux RBAC to make that happen?
> >>>>>>
> >>>>>> I have tried various approaches without success.  I have
> >>>>>> also
> >>>>>> tried
> >>>>>> the
> >>>>>> steps in http://forums.fedoraforum.org/archive/index.php/t-
> >>>>>> 2229
> >>>>>> 38.htm
> >>>>>> l
> >>>>>> without success.
> >>>>>>
> >>>>>> I would greatly appreciate any hints.
> >>>>> Perhaps you could describe what you tried in more detail, and
> >>>>> how
> >>>>> it
> >>>>> failed.  The thing to remember is that for your scenario
> >>>>> above,
> >>>>> you
> >>>>> need to control read permission, not execute permission.  You
> >>>>> can
> >>>>> either do this via RBAC/TE (in which case you need separate
> >>>>> SELinux
> >>>>> users, roles, and domains for jack and mary, and separate
> >>>>> types
> >>>>> for
> >>>>> jack.jar and mary.jar), or via MCS/MLS (in which case you
> >>>>> need to
> >>>>> have
> >>>>> jack and mary run in MCS constrained domains, authorize them
> >>>>> for
> >>>>> different categories, and assign those different categories
> >>>>> to
> >>>>> the .jar
> >>>>> files).
> >>>> Thank you for making me realize that the access control that I
> >>>> need
> >>>> is
> >>>> indeed read, not execute.
> >>>>
> >>>> I will try again via RBAC/TE and will provide details on what I
> >>>> tried
> >>>> if I still cannot get it to work.
> >>>>
> >>>>> Perhaps the better question is what is it that you are really
> >>>>> trying to
> >>>>> achieve.  Merely controlling which jar files they can
> >>>>> read/execute
> >>>>> isn't terribly interesting; what prevents them from just re-
> >>>>> creating or
> >>>>> downloading the other .jar file themselves?
> >>>> I am trying to implement the least privilege concept on a
> >>>> particular
> >>>> system.  At this point it is fine if the user copies the other
> >>>> JAR
> >>>> file to other systems since it will not run as expected on that
> >>>> other
> >>>> system.  But this may become a requirement later...
> >>>>
> >>>> Thanks!
> >>>>
> >>>> Bill
> >>>>
> >>>>> _______________________________________________
> >>>>> selinux mailing list -- selinux(a)lists.fedoraproject.org
> >>>>> To unsubscribe send an email to selinux-leave(a)lists.fedorapro
> >>>>> ject
> >>>>> .org