TOMOYO
Contents
Introduction to TOMOYO
The fundamental concept of TOMOYO Linux is "tracking process invocation history". TOMOYO Linux splits domains using "process invocation history" and the process transits to a different domain whenever execution of a program (i.e. do_execve()) is requested. By transiting to a different domain whenever execution of a program is requested, each domain will have the minimal permissions that are essential for processes in that domain to do their roles. For more information, see http://tomoyo.sourceforge.jp/wiki-e/?WhatIs.
Project Homepage: http://tomoyo.sourceforge.jp/en/2.1.x/
Dependencies
Required
- OpenSSL needed for mailauth function of TOMOYO tools
Note
Rebuild Kernel
2.6.22 Kernel and TOMOYO 1.5
Extract the TOMOYO 1.5 patches and modify the patch file ccs-patch-2.6.22.txt:
8<=========== change for version ============>8 -EXTRAVERSION = .9-cfs-v22 +EXTRAVERSION = .9-cfs-v22-ccs 8<=========== chang for CFS v22 patch http://lkml.org/lkml/2007/9/26/97 ============>8 @@ -64,5 +64,8 @@ #include <asm/tlb.h> +/***** TOMOYO Linux start. *****/ +#include <linux/tomoyo.h> +/***** TOMOYO Linux end. *****/ /* * Scheduler clock - returns current time in nanosec units. @@ -4060,6 +4063,9 @@ int can_nice(const struct task_struct *p 8<=======================>8
Patch the kernel source:
patch -Np1 -i ../sched-cfs-v2.6.22.9-v22.patch && patch -Np1 -i ../ccs-patch-2.6.22.txt
Compile and install a new TOMOYO aware kernel. Ensure you enable the TOMOYO features.
2.6.23 Kernel and TOMOYO 1.5
TOMOYO 1.5 has some features like network and mount operations control that not currently available in TOMOYO 2.x. so TOMOYO 1.5 is a better choice than TOMOYO 2.x.
Patche the kernel source:
patch -Np1 -i ../ccs-patch-2.6.23-rc7.txt
Compile and install a new TOMOYO aware kernel. Ensure you enable the TOMOYO features.
2.6.23 Kernel and TOMOYO 2.x
Extract the TOMOYO 2.x patches to the kernel source directory.
for i in `cat ../patches/series`; do patch -Np1 < ../patches/$i; done
Compile and install a new TOMOYO aware kernel. Ensure you enable the TOMOYO features. Go to "Security options" screen and unselect "Default Linux Capabilities", "Root Plug Support", "NSA SELinux Support" and select "TOMOYO Linux support" as shown below.
[*] Enable different security models < > Default Linux Capabilities < > Root Plug Support [ ] NSA SELinux Support [*] TOMOYO Linux support
Build TOMOYO Tools
Non-Multilib
Compile the package:
make
Install the package:
make install
Multilib
32Bit
Compile the package:
make CC="gcc ${BUILD32}"
Install the package:
make install
N32
Compile the package:
sed -i 's@/usr/lib@/usr/lib32@g' Makefile &&
make CC="gcc ${BUILDN32}"
Install the package:
make install
64Bit
Compile the package:
sed -i 's@/usr/lib@/usr/lib64@g' Makefile &&
make CC="gcc ${BUILD64}"
Install the package:
make install
Configuring
Configuring TOMOYO 1.5
Run init_policy.sh to perform initial configuration for ccs patch
/usr/lib/ccs/init_policy.sh
You will get initial configuration files in /etc/ccs/ directory.
Configuring TOMOYO 2.x
Run tomoyo_init_policy.sh to perform initial configuration for TOMOYO 2.x.
/usr/lib/ccs/tomoyo_init_policy.sh
You will get initial configuration files in /etc/tomoyo/ directory.
Configuring TOMOYO audit logging
cat > /etc/rc.d/init.d/ccs-auditd << EOF #!/bin/sh /usr/lib/ccs/ccs-auditd /dev/null /var/log/tomoyo/reject_log.txt EOF
chmod +x /etc/rc.d/init.d/ccs-auditd
for i in 2 3 4 5; do
ln -sv ../init.d/ccs-auditd /etc/rc.d/rc${i}.d/S99ccs-auditd; done
mkdir -p /var/log/tomoyo
Configuring TOMOYO to begin from learning mode
Configure TOMOYO Linux to learn system behavior.
echo '<kernel>' > /etc/tomoyo/domain_policy.conf echo 'use_profile 1' >> /etc/tomoyo/domain_policy.conf
Boot TOMOYO Linux
When you boot with TOMOYO Linux kernel, you will see the following message when /sbin/init is about to start.
TOMOYO Linux: Enter 'disable' within 10 seconds to disable TOMOYO Linux. TOMOYO Linux>
If you press 'Enter' key or wait for 10 seconds, TOMOYO Linux gets enabled and policy is loaded. If you have trouble such as unable to login because of inappropriate TOMOYO Linux configuration, enter "disable" and press 'Enter' key to disable TOMOYO Linux.
grub menu can use CCS=default to boot using default policy without waiting.
root=/dev/hda8 ro vga=791 video=neofb:ywrap,mtrr acpi=off CCS=default
newer version of /sbin/{ccs,tomoyo}-init from http://svn.sourceforge.jp/cgi-bin/viewcvs.cgi?rev=580&root=tomoyo&view=rev can be used, and with CCS=ask to let user select from available policies at boot time.
Configuring policy to guard Linux as needed
Login to the system as root user, and run editpolicy included in TOMOYO Linux tools.
/usr/lib/ccs/editpolicy
Contents
| Download Source | http://osdn.dl.sourceforge.jp/tomoyo/27220/ccs-tools-Template:CCSTools-Version.tar.gz |
|---|---|
| Download Patch (for 2.6.22 series Kernel): | http://people.redhat.com/mingo/cfs-scheduler/sched-cfs-v2.6.22.9-v22.patch |
| Download Patch (TOMOYO 1.5 for 2.6.22 or 2.6.23 Kernel): | http://osdn.dl.sourceforge.jp/tomoyo/27219/ccs-patch-1.5.0-20070920.tar.gz |
| Download Patch (TOMOYO 2.1 for 2.6.23 series Kernel): | http://svn.sourceforge.jp/cgi-bin/viewcvs.cgi/tags/lkml/4/patches.tar.gz?root=tomoyo&view=tar |
| Installed Directories: | /usr/lib/ccs |
|---|---|
| Installed Programs: | tomoyo_init_policy.sh, init_policy.sh, editpolicy, editpolicy_offline, setlevel, setprofile, ccstree, savepolicy, makesyaoranconf, ccs-auditd, findtemp, sortpolicy, ld-watch, ccs-queryd, checkpolicy, /sbin/{ccs,tomoyo}-init |
| Installed Libraries: |
Short Descriptions
| editpolicy | Edits the current policy in /proc/ccs/ directory |
|---|---|
| editpolicy_offline | Edits the policy in /etc/ccs/ directory. |
| setlevel | Changes the current control level (i.e. writing to /proc/ccs/profile ) and displays the new control level. |
| setprofile | Assigns a profile to domains. |
| ccstree | Lists the domainnames of currently running processes belong to and the profile numbers the domains currently assigned to. |
| savepolicy | Saves the on-memory policy onto disk. |
| makesyaoranconf | Generates syaoran.conf, the configuration file for SYAORAN (the Tamper-Proof /dev filesystem). You can use SYAORAN filesystem if you want to run the system with read-only root fs or you want to prevent device files from tampering. |
| ccs-auditd | Reads from /proc/ccs/grant_log and /proc/ccs/reject_log and writes to the location given in the commandline parameters. |
| sortpolicy | Remove duplicated entry from logs written by "ccs-auditd". |
| findtemp | Reads domain policy from standard input and checks the existence of pathnames, and dumps the nonexistent pathnames. |
| ld-watch | Appends shared libraries to exception policy automatically using "allow_read" directive when the location of shared libraries in /etc/ld.so.cache has changed. |
| ccs-queryd | Detects policy violation and displays the access request. You can tell the system whether the access request should be granted (or granted and policy should be appended to grant the access request) or rejected after you validate the access request.
By running this program while updating packages, you can avoid errors due to insufficient permissions. Never grant access requests unconditionally. The cause of policy violation is not always updating packages, but may by malicious requests by attackers. If you grant access requests caused by malicious requests by attackers, the system gets intruded. To enable "delayed enforcing mode", you need to either set "ALLOW_ENFORCE_GRACE=1" in /proc/ccs/profile using "setlevel" command or assign a profile whose ALLOW_ENFORCE_GRACE is set to 1 to domains using "setprofile" command. |
| checkpolicy | Reads policy files from standard input and checks syntaxes. |
| ccs-init | Loads policy files from /etc/ccs/ directory.
Put this program as /sbin/ccs-init , and this program will be invoked automatically when execution of /sbin/init is requested by initrd. |
