SEforAndroid

From SELinux Wiki

(Difference between revisions)
Jump to: navigation, search
Revision as of 18:24, 18 March 2013 (edit)
StephenSmalley (Talk | contribs)
(Middleware MAC)
← Previous diff
Current revision (12:54, 17 June 2014) (edit) (undo)
StephenSmalley (Talk | contribs)
(Replacing page with 'The content of this page has moved to http://seandroid.bitbucket.org/, please update your bookmarks or links.')
 
(273 intermediate revisions not shown.)
Line 1: Line 1:
-== What is SE Android? ==+The content of this page has moved to http://seandroid.bitbucket.org/,
- +please update your bookmarks or links.
-Security Enhanced (SE) Android is a project to identify and address critical gaps in the security of Android. Initially, the SE Android project is enabling the use of SELinux in Android in order to limit the damage that can be done by flawed or malicious apps and in order to enforce separation guarantees between apps. However, the scope of the SE Android project is not limited to SELinux.+
- +
-SE Android also refers to the reference implementation produced by the SE Android project. The current SE Android reference implementation provides a worked example of how to enable and apply SELinux at the lower layers of the Android software stack and provides a working demonstration of the value provided by SELinux in confining various root exploits and application vulnerabilities.+
- +
-== SE Android Papers and Presentations ==+
- +
-* The Case for SE Android, Linux Security Summit 2011, Sep 2011. [http://selinuxproject.org/~jmorris/lss2011_slides/caseforseandroid.pdf Slides]+
-* The Case for Security Enhanced (SE) Android, Android Builders Summit 2012, Feb 2012. [https://events.linuxfoundation.org/images/stories/pdf/lf_abs12_smalley.pdf Slides] [http://video.linux.com/videos/the-case-for-security-enhanced-se-android Video]+
-* Security Enhanced (SE) Android, 16th Semi-Annual Software Assurance Forum, Mar 2012. [https://buildsecurityin.us-cert.gov/swa/presentations_032612/SE%20Android%20(Panel%20on%20Securing%20Mobile%20Operatins%20Systems)%20-%20Stephen%20Smalley.pdf Slides]+
-* Security Enhanced (SE) Android, LinuxCon North America 2012, Aug 2012. [https://events.linuxfoundation.org/images/stories/pdf/lcna_co2012_smalley.pdf Slides]+
-* Middleware MAC for Android, Linux Security Summit 2012, Aug 2012. [http://kernsec.org/files/LSS2012-MiddlewareMAC.pdf Slides]+
-* Security Enhanced (SE) Android: Bringing Flexible MAC to Android, 20th Annual Network and Distributed System Security Symposium (NDSS '13), Feb 2013. [http://selinuxproject.org/~seandroid/papers/NDSS2013-SEAndroid-Paper.pdf Paper] [http://selinuxproject.org/~seandroid/slides/NDSS2013-SEAndroid-Presentation.pdf Slides]+
-* Laying a Secure Foundation for Mobile Devices, 20th Annual Network and Distributed System Security Symposium (NDSS '13), Feb 2013. [http://selinuxproject.org/~seandroid/slides/NDSS2013-Keynote.pdf Slides]+
- +
-== How do I get the SE Android code? ==+
- +
-First, you should make sure that you are able to successfully download, build and run the Android Open Source Project (AOSP) source code by following the instructions starting from+
-http://source.android.com/source/initializing.html.+
- +
-The AOSP instructions are for Ubuntu or MacOS X users; we are building on+
-64-bit Fedora.+
-Some Fedora-specific notes can be found further below. Ubuntu or MacOS X should also work as build hosts;+
-see the AOSP instructions for specific information about building AOSP on those operating systems.+
- +
-General questions about building and running Android should be directed to the android-building discussion group. Only questions specific to SE Android should be directed to the seandroid-list mailing list.+
- +
-=== Using the master branch ===+
- +
-SE Android development is done relative to the master branch of AOSP, with our changes on a+
-seandroid branch. If you want to work with the latest SE Android code, you should clone the master+
-branch of AOSP as your starting point.+
- +
-Once you have successfully built and run AOSP, you can obtain a local_manifest.xml file specifying the SE Android git trees from+
-https://bitbucket.org/seandroid/manifests.+
-Copy this file to the .repo subdirectory of your AOSP clone, and+
-then run repo sync. Your tree should now include the SE Android modifications.+
- +
-The git projects can be accessed using https or ssh. Cloning via https can sometimes fail, particularly for large repos.+
-Cloning via ssh requires that you first set up an account on bitbucket.org and upload a public key.+
- +
-An abbreviated example sequence of commands is shown below for downloading the AOSP master branch with+
-the SE Android modifications using https-based access.+
-<pre>+
-git clone https://bitbucket.org/seandroid/manifests.git+
-mkdir seandroid+
-cd seandroid+
-repo init -u https://android.googlesource.com/platform/manifest+
-repo sync+
-cp ../manifests/local_manifest.xml .repo+
-repo sync+
-</pre>+
- +
-If you have set up an account on bitbucket.org and uploaded a ssh public key, you can use the ssh-based local manifest instead,+
-as shown below.+
-<pre>+
-git clone -b master-ssh git@bitbucket.org:seandroid/manifests.git+
-mkdir seandroid+
-cd seandroid+
-repo init -u https://android.googlesource.com/platform/manifest+
-repo sync+
-cp ../manifests/local_manifest.xml .repo+
-repo sync+
-</pre>+
- +
-=== Using a release version ===+
- +
-We have created branches of SE Android relative to specific Android release versions, as shown by the table below.+
-The base version is the name of the AOSP release tag from which the branch was forked. If you want to use a stable release of Android as+
-your baseline, then you should clone the corresponding release tag of AOSP as your starting point.+
- +
-{| +
- ! align="left" | Base Version+
- ! align="left" | SE Branch+
- |-+
- | android-4.2.2_r1+
- | seandroid-4.2+
- |-+
- | android-4.1.2_r1+
- | seandroid-4.1.2+
- |-+
- | android-4.0.4_r2.1+
- | seandroid-4.0.4+
- |}+
- +
-Once you have successfully built and run the AOSP sources, you can obtain the version-specific local_manifest.xml file from+
-the corresponding seandroid-4.x.y branch of https://bitbucket.org/seandroid/manifests.+
-Copy this file to the .repo subdirectory of your AOSP clone, and+
-then run repo sync. Your tree should now include the SE Android modifications relative+
-to the released version.+
- +
-An abbreviated example sequence of commands is shown below for downloading Android 4.2 with+
-the SE Android modifications.+
-<pre>+
-git clone -b seandroid-4.2 https://bitbucket.org/seandroid/manifests.git+
-mkdir seandroid-4.2+
-cd seandroid-4.2+
-repo init -u https://android.googlesource.com/platform/manifest -b android-4.2.2_r1+
-repo sync+
-cp ../manifests/local_manifest.xml .repo/+
-repo sync+
-</pre>+
- +
-If you want to use ssh-based access instead, have set up an account on bitbucket.org and have uploaded a ssh public key,+
-you can use the -ssh branch of the manifests project.+
-<pre>+
-git clone -b seandroid-4.2-ssh git@bitbucket.org:seandroid/manifests.git+
-mkdir seandroid-4.2+
-cd seandroid-4.2+
-repo init -u https://android.googlesource.com/platform/manifest -b android-4.2.2_r1+
-repo sync+
-cp ../manifests/local_manifest.xml .repo/+
-repo sync+
-</pre>+
- +
-The same instructions can be applied for other versions such as 4.1.2 or 4.0.4.+
- +
-== Git Trees and Branches ==+
- +
-In addition to using repo to clone SE Android, it is also possible to+
-directly clone the SE Android git repos via git if you merely want to+
-examine the trees. The trees can be cloned via:+
-<pre>+
-git clone https://bitbucket.org/seandroid/ + project path+
-</pre>+
-where the "+ project path" is replaced by the path to the specific git project+
-you wish to clone.+
- +
-The manifests git project contains the local_manifest.xml files. The master branch+
-contains a local_manifest.xml file referencing the seandroid branch relative to AOSP master,+
-while the seandroid-4.x.y branches contain a local_manifest.xml file referencing the seandroid-4.x.y branches+
-relative to specific AOSP releases.+
- +
-Each kernel tree has a seandroid-<board>-<version> branch that was+
-forked from the existing android-<board>-<version> branch. You can+
-extract individual patches from the kernel trees by running git+
-format-patch <remote-name>/android-<board>-<version>. If you cloned via repo,+
-then the <remote-name> will be bitbucket; if you cloned directly via git clone, then+
-the <remote-name> will be origin. Example for the Galaxy Nexus kernel:+
-<pre>+
-cd kernel/omap+
-git branch -r+
-git checkout bitbucket/seandroid-omap-tuna-3.0-jb-mr1.1+
-git format-patch bitbucket/android-omap-tuna-3.0-jb-mr1.1+
-</pre>+
- +
-Each modified AOSP tree has a seandroid branch that was forked from+
-the master branch and a set of seandroid-x.y.z branches. You can extract individual patches from the AOSP trees+
-by running git format-patch <remote-name>/master (for the seandroid branch) or+
-git format-patch <release-tag> (for the seandroid-x.y.z branches). +
-Example for frameworks/base relative to the master branch,+
-assuming you cloned the seandroid branch:+
-<pre>+
-cd seandroid/frameworks/base+
-git format-patch bitbucket/master+
-</pre>+
- +
-Example for frameworks/base relative to the 4.2 release,+
-assuming you cloned the seandroid-4.2 branch:+
-<pre>+
-cd seandroid-4.2/frameworks/base+
-git format-patch android-4.2.2_r1+
-</pre>+
- +
-libsepol, checkpolicy, libselinux and sepolicy are new trees added for SE Android.+
-libsepol and checkpolicy are a port of the SELinux policy compiler, modified slightly+
-to build as part of Android and to build on MacOS X. These two components are only built+
-for the build host and are not installed to the device. libselinux is a port of a subset of the upstream libselinux to Android plus some new Android-specific interfaces, while sepolicy is a completely new SELinux policy written from scratch for Android. libselinux is built for both the build host (for use by certain build tools) and for the device. sepolicy is built once; the binary policy format is architecture-independent.+
- +
-== Fedora-Specific Notes ==+
- +
-AOSP only officially supports building on specific versions of Ubuntu and MacOS X.+
-We have been building on Fedora in addition to Ubuntu and MacOS X. This section contains some tips for building+
-on Fedora if you wish to do so. We have successfully built on 64-bit Fedora. Beyond a typical install, we typically have+
-to install the following to build AOSP. The precise package list may+
-vary for different versions of Fedora.+
-<pre>+
-yum groupinstall "Development Tools" "Development Libraries"+
-yum install gperf perl-Switch+
-yum install glibc.i686 glibc-devel.i686 libstdc++.i686 zlib-devel.i686 ncurses-devel.i686 libX11-devel.i686 libXrender.i686 libXrandr.i686 readline-devel.i686 mesa-libGL-devel.i686+
-</pre>+
- +
-AOSP only officially supports the Oracle/Sun JDK, not OpenJDK. Improved+
-support for OpenJDK has been going into the master branch, but it is+
-unclear as to whether it yields a working result. We are presently+
-building with the Sun JDK. Obtain the Oracle/Sun JDK, install it, and remove+
-OpenJDK or make sure the Oracle/Sun JDK location comes first in your PATH.+
- +
-The Android build process requires allowing executable stacks.+
-<pre>+
-setsebool allow_execstack=1+
-</pre>+
- +
-Use setsebool -P if you want this change to persist across reboots.+
- +
-You may need to patch the LOCAL_LDLIBS definitions of some makefiles+
-to include all library dependencies. We had to add LOCAL_LDLIBS += -lX11+
-to development/tools/emulator/opengl/host/renderer/Android.mk.+
- +
-You will need to add udev rules under /etc/udev/rules.d if you want to+
-be able to access a device via adb without being root. For example:+
-<pre>+
-$ cat /etc/udev/rules.d/51-android.rules+
-ATTR{idVendor}=="18d1", MODE="0666"+
-ATTR{idVendor}=="22b8", MODE="0666"+
-ATTR{idVendor}=="04e8", MODE="0666"+
-</pre>+
- +
-You can get adb, fastboot, etc in your path by running the+
-following:+
-<pre>+
-export PREFIX=/path/to/your/aospclone+
-cd $PREFIX+
-source build/envsetup.sh+
-setpaths+
-</pre>+
- +
-If you have run lunch in the same shell in order to build AOSP,+
-then your path is already set correctly.+
- +
-== Building for the Emulator ==+
- +
-In order to run SE Android on the Android emulator, you need a+
-modified kernel with the necessary support for SELinux. The+
-emulator kernel is located under kernel/goldfish.+
-<pre>+
-export PREFIX=/path/to/your/aospclone+
-cd $PREFIX/kernel/goldfish+
-make ARCH=arm goldfish_armv7_defconfig+
-make ARCH=arm CROSS_COMPILE=$PREFIX/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin/arm-eabi-+
-</pre>+
- +
-If building 4.0.4, the compiler toolchain has a different path,+
-<pre>+
-make ARCH=arm CROSS_COMPILE=$PREFIX/prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-+
-</pre>+
- +
-On MacOS X, you need to specify the darwin-x86 compiler toolchain instead of the linux-x86 toolchain:+
-<pre>+
-make ARCH=arm CROSS_COMPILE=$PREFIX/prebuilts/gcc/darwin-x86/arm/arm-eabi-4.6/bin/arm-eabi-+
-</pre>+
-and you must follow the steps described in:+
-http://code.google.com/p/android/issues/detail?id=2755+
- +
-You can build the Android userspace in the usual manner, except that you must specify HAVE_SELINUX=true on the make command line or set it in your environment prior to running make:+
-<pre>+
-cd $PREFIX+
-source build/envsetup.sh+
-lunch full-eng+
-export HAVE_SELINUX=true+
-make+
-</pre>+
- +
- +
-You must run the emulator with the kernel you built:+
-<pre>+
-emulator -show-kernel -kernel kernel/goldfish/arch/arm/boot/zImage+
-</pre>+
- +
-The above command presumes that you previously ran lunch (as during a+
-build) or manually set your ANDROID_PRODUCT_OUT and PATH variables+
-appropriately.+
- +
-== Building for the x86-based Emulator ==+
- +
-Building for the Android x86 emulator is similar to the above instructions, but using+
-the x86 goldfish_defconfig as the kernel configuration and the+
-full_x86-eng userspace build target.+
-To build the kernel, you can do the following:+
-<pre>+
-export PREFIX=/path/to/your/aospclone+
-cd $PREFIX/kernel/goldfish+
-../../external/qemu/distrib/build-kernel.sh --arch=x86+
-</pre>+
- +
-You can build the Android userspace for x86 as follows:+
-<pre>+
-cd $PREFIX+
-source build/envsetup.sh+
-lunch full_x86-eng+
-export HAVE_SELINUX=true+
-make+
-</pre>+
- +
-You must run the emulator with the kernel you built:+
-<pre>+
-emulator -show-kernel -kernel kernel/goldfish/arch/x86/boot/bzImage+
-</pre>+
- +
-The above command presumes that you previously ran lunch (as during a+
-build) or manually set your ANDROID_PRODUCT_OUT and PATH variables+
-appropriately.+
- +
-== Building for a Device ==+
- +
-It is advisable to make a backup of your device prior to trying to+
-install AOSP on it, typically using a recovery ROM such as+
-ClockworkMod. Also note that you will erase your user data when you+
-unlock the bootloader. Finally, keep in mind that AOSP does not+
-include various proprietary apps such as the Google apps so you will+
-not have them in your build unless you extract a copy from your device+
-and re-package them for your build.+
- +
-As in the emulator case, you will need to build a modified kernel with+
-the necessary support for SELinux. Various kernels are available+
-under the kernel/ directory. Use the right kernel tree, branch and+
-configuration for your device; the defconfig files have been modified+
-to enable the necessary options for SELinux. For example, to build+
-for the Galaxy Nexus phone, you would do the following:+
-<pre>+
-export PREFIX=/path/to/your/aospclone+
-cd $PREFIX/kernel/omap+
-make ARCH=arm tuna_defconfig+
-make ARCH=arm CROSS_COMPILE=$PREFIX/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin/arm-eabi-+
-</pre>+
- +
-On MacOS X, you need to specify the darwin-x86 compiler toolchain instead of the linux-x86 toolchain:+
-<pre>+
-make ARCH=arm CROSS_COMPILE=$PREFIX/prebuilts/gcc/darwin-x86/arm/arm-eabi-4.6/bin/arm-eabi-+
-</pre>+
- +
-If building 4.0.4, the compiler toolchain has a different path,+
-<pre>+
-make ARCH=arm CROSS_COMPILE=$PREFIX/prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-+
-</pre>+
- +
-General AOSP instructions for building kernels can be found at:+
-http://source.android.com/source/building-kernels.html.+
-However, those instructions are for rebuilding the kernel that matches the AOSP prebuilt kernel;+
-you will need to instead use our branches or port our modifications over to the kernel you are using.+
-The correct kernel project, branch, and config to use for each device is shown below. Note that+
-there may be multiple branches in the same kernel project for different Android versions (e.g. samsung) or different+
-devices (e.g. omap, tegra). Older branches may also exist for earlier Android releases.+
- +
-{| +
- ! align="left" | Version+
- ! align="left" | Device+
- ! align="left" | Project+
- ! align="left" | Branch+
- ! align="left" | Config+
- |-+
- | 4.2.2+
- | Nexus 10+
- | kernel/exynos+
- | seandroid-exynos-manta-3.4-jb-mr1.1+
- | manta_defconfig+
- |-+
- | 4.2.2+
- | Nexus 4+
- | kernel/msm+
- | seandroid-msm-mako-3.4-jb-mr1.1+
- | mako_defconfig+
- |-+
- | 4.2.2+
- | Nexus 7+
- | kernel/tegra+
- | seandroid-tegra3-grouper-3.1-jb-mr1.1+
- | tegra3_android_defconfig+
- |-+
- | 4.2.2+
- | Galaxy Nexus+
- | kernel/omap+
- | seandroid-omap-tuna-3.0-jb-mr1.1+
- | tuna_defconfig+
- |-+
- | 4.1.2+
- | Nexus S+
- | kernel/samsung+
- | seandroid-samsung-3.0-jb-mr0+
- | herring_defconfig+
- |-+
- | 4.1.2+
- | Motorola Xoom+
- | kernel/tegra +
- | seandroid-tegra-moto-2.6.39-jb-mr0 +
- | stingray_defconfig+
- |-+
- | master+
- | PandaBoard+
- | kernel/omap+
- | seandroid-omap-panda-3.0+
- | panda_defconfig+
- |} +
- +
-For the device, you need your modified kernel to be included in the+
-boot partition image (boot.img) rather than the prebuilt kernel.+
-We have modified the device/<vendor>/<board>/device.mk files in our branches to refer to a locally built kernel rather than the prebuilt ones.+
-You can do the same for other devices.+
-You can alternatively unpack the boot image and repack it with your own+
-kernel after building AOSP.+
- +
-Follow the AOSP instructions for building for your device+
-as per+
-http://source.android.com/source/building-devices.html+
-except that you will need to specify HAVE_SELINUX=true on the make command line+
-or set it in your environment prior to running make, e.g.+
-<pre>+
-cd $PREFIX+
-source build/envsetup.sh+
-lunch full_maguro-userdebug+
-export HAVE_SELINUX=true+
-make+
-</pre>+
- +
-The above example uses the userdebug build variant. For a production build, you should use a user build instead, e.g.+
-<pre>+
-lunch full_maguro-user+
-</pre> +
- +
-The build system signs packages with the testkeys provided in the source tree. Because the testkeys are part of the standard Android open source distribution, they should never be used for production devices. Instead, you should generate and use your own private keys for creating production builds. Some information about how to do this is included in the (old, removed from source.android.com) Android Platform Developer Guide, in the development/pdk/docs/porting/release_keys.jd file. Note that if you generate your own keys for signing, you need to update the external/sepolicy/keys.conf configuration with the paths to the production keys. This configuration is used to generate the final mac_permissions.xml configuration.+
- +
-== Getting Started with SE Android ==+
- +
-Once you have the emulator or a device running SE Android, you can run adb shell and then look for signs that SELinux is present, e.g.+
-<pre>+
-getenforce+
-ls -Z+
-ps -Z+
-dmesg+
-</pre>+
- +
-The Settings app will also show you your current SELinux status+
-(disabled, permissive, or enforcing) under About phone or tablet.+
-The separate SEAndroidManager app allows you to change your enforcing status and policy booleans.+
- +
-By default, the system will be in permissive mode, i.e. it will log+
-SELinux denials but not enforce them. Before putting it into enforcing+
-mode, make sure you don't have any residual denials to address in your+
-policy, e.g.+
-<pre>+
-adb shell su 0 dmesg | grep avc+
-</pre>+
-or, if running auditd,+
-<pre>+
-adb shell su 0 cat /data/misc/audit/audit.log | grep avc+
-</pre>+
-should show no output.+
- +
-To set enforcing mode at runtime, you can run "setenforce 1"+
-from an adb root shell, e.g.:+
-<pre>+
-adb shell su 0 setenforce 1+
-</pre>+
- +
-To cause the phone to always boot in enforcing mode, +
-add "setenforce 1" to one of the init.rc files, rebuild,+
-and reflash your boot image.+
- +
-Alternatively, you can use the SEAndroidManager app to set your enforcing status.+
-The enforcing status will be saved and restored by the app on each boot.+
- +
-If not running auditd, you can capture policy denials for later use in policy debugging as follows:+
-<pre>+
-adb shell su 0 cat /proc/kmsg > dmesg.txt &+
-</pre>+
- +
-If running auditd, the denials will be written instead to /data/misc/audit/audit.log on the device.+
- +
-You can later apply standard SELinux tools such as audit2allow to these logs, as in:+
-<pre>+
-audit2allow -p out/target/product/<device>/root/sepolicy < dmesg.txt+
-</pre>+
- +
-However, note that you must specify that you are using a policy other than the SELinux policy +
-active on the build host.+
- +
-== SE Android Policy ==+
- +
-The SE Android policy sources are located under external/sepolicy.+
-The policy consists of source files used to generate the SELinux+
-kernel policy file, a file_contexts configuration, a +
-property_contexts configuration, a seapp_contexts configuration, and a mac_permissions.xml configuration.+
-The file_contexts configuration is used+
-to label files at build time (e.g. the system partition) and at+
-runtime (e.g. device nodes, service socket files, /data directories created+
-by init.rc, ...). The property_contexts configuration is used to specify+
-the security context of Android properties for permission checking purposes.+
-The seapp_contexts configuration is used to label app processes and app package directories. The mac_permissions.xml configuration is the middleware MAC policy. The property_contexts, seapp_contexts, and mac_permissions.xml configurations are unique to SE Android (i.e. they were not part of the regular SELinux policy).+
- +
-Device-specific policy can be specified by defining BOARD_SEPOLICY_DIRS, BOARD_SEPOLICY_UNION and/or BOARD_SEPOLICY_REPLACE variables in a BoardConfig.mk file under the device/<vendor>/<device> or vendor/<vendor>/<device> directories. An example can be found in device/samsung/tuna/BoardConfig.mk, which defines these variables to reference device-specific policy files under device/samsung/tuna/sepolicy. Documentation for per-device policy can be found in external/sepolicy/README.+
- +
-SE Android kernel policy is presently compiled as part of the Android build+
-and added to the ramdisk image so that it can be loaded by init very+
-early in boot, before mounting the system partition. Once the data partition has been mounted, policy can+
-be reloaded from /data/security by placing policy files under /data/security and setting the selinux.reload_policy+
-property to 1 (setprop selinux.reload_policy 1). This will trigger a reload of policy by init, which will also restart ueventd and installd so that they can reload the policy configuration files relevant to their operation. Note that for the kernel policy, you must recompile the sepolicy file (make sepolicy) on the build host and push that to /data/security, not the source .te files. If you want the policy to be loaded from /data/security automatically on each boot, add the setprop command to the post-fs-data section of the init.rc file.+
- +
-== Running the CTS ==+
- +
-If you want to run the Android Compatibility Test Suite (CTS) with SE Android, you should follow the+
-standard instructions as per+
-http://source.android.com/compatibility/.+
- +
-Additionally, you will need to set the android_cts policy boolean to enable certain policy rules that+
-are specific to the CTS instrumentation that runs on the device, and you will need to enable enforcing mode+
-if you want to test the impact of an enforcing SE Android system. This can be done by executing the following+
-commands before running the CTS. You should make sure you can run the CTS successfully in permissive mode before+
-trying enforcing mode.+
-<pre>+
-adb shell su 0 setsebool android_cts=1+
-adb shell su 0 setenforce 1+
-</pre>+
- +
-You can also add the setsebool and setenforce commands to your init.rc file to cause them to be executed automatically+
-on each boot of the device.+
- +
-You may wish to collect any permission denials and log messages that occur during the CTS execution for later use in+
-diagnosing failures and amending the policy to better support the CTS. Policy changes that are specific to the CTS+
-instrumentation on the device should go into the sepolicy/cts.te file within the if (android_cts) conditional block, while+
-generic changes suitable for production devices should be integrated into the appropriate policy files.+
-<pre>+
-adb shell su 0 cat /proc/kmsg > dmesg.txt &+
-adb shell logcat *:E > log.txt &+
-</pre>+
- +
-== Middleware MAC ==+
- +
-In addition to the base SE Android code, we have a set of experimental extensions to the Android middleware that provide different forms of mandatory restrictions over the Android permissions model. One of these extensions, install-time MAC (described below), is now merged into the base SE Android code. The other extensions, permission revocation and intent MAC, are only presently available in their own separate feature branches. The mechanisms and their branches are:+
-* Install-time MAC (merged to seandroid),+
-* Permission revocation (revoke-perms),+
-* Intent MAC (intent_mac).+
- +
-=== Install-time MAC ===+
- +
-This mechanism applies an install-time check of app permissions against a MAC policy configuration (found in+
-external/sepolicy/mac_permissions.xml in the source tree and as etc/security/mac_permissions.xml on the system image).+
-The persist.mmac.enforce system property controls whether the MAC restrictions are enforced; this can be set via+
-SEManager app or via setprop. If permissive, then the mechanism will simply log MAC denials, which can be viewed and saved via SEManager. An updated mac_permissions.xml configuration can be pushed to /data/security/mac_permissions.xml to override the configuration on the system image on the next boot. This support is included in the base SE Android code. The setool program can be used to generate policy stanzas for mac_permissions.xml, or to check whether a given apk would violate a given mac_permissions.xml configuration.+
-<pre>+
-setool --build whitelist /path/to/foo.apk+
-setool --policy /path/to/mac_permissions.xml /path/to/foo.apk+
-</pre>+
- +
-=== Permission Revocation ===+
- +
-This mechanism, based on a similar mechanism in CyanogenMod, supports revocation of permissions from installed apps.+
-A revoked permission list is maintained for each package and checked at runtime on permission checks. A revoked permissions configuration (found in external/mac-policy/revoke_permissions.xml in the source tree and as etc/security/revoke_permissions.xml on the system image) can specify revocation lists that are applied automatically on each boot. An updated revoke_permissions.xml configuration can be pushed to /data/system/revoke_permissions.xml to override the configuration on the system image on the next boot. This support is available from the revoke-perms branch.+
- +
-=== Intent MAC ===+
- +
-Intent MAC supports a white-list of Intents and the types of their sources and destinations. Currently, we only protect delivery of Intents to Activities, Broadcast Receivers, and Services. Content Providers are not yet protected. We support filtering of Intents to the action string granularity; data and category field filtering are not yet implemented. This support is available from the intent_mac branch.+
- +
-== For More Information ==+
- +
-Questions about SE Android may be directed to the public seandroid-list AT tycho.nsa.gov mailing list.+
-You can subscribe to the list by sending an email containing "subscribe seandroid-list" as the body (not the subject)+
-to majordomo AT tycho.nsa.gov. You must subscribe before posting to seandroid-list AT tycho.nsa.gov. List archives are available+
-via majordomo (using the index and get commands). The archives can also be read or searched via [http://dir.gmane.org/gmane.comp.security.seandroid GMANE] or [http://www.mail-archive.com/seandroid-list@tycho.nsa.gov/info.html mail-archive.com].+
- +
-You may also send private email to our team alias, seandroid AT tycho.nsa.gov.+
-However, whenever possible, please use the public mailing list.+
- +
-Early SE Android discussions occurred on the public selinux mailing list prior to the creation of the seandroid-list.+
-You can search the selinux mailing list archives at [http://marc.info/?l=selinux MARC] or [http://dir.gmane.org/gmane.comp.security.selinux GMANE] for "android" if you want to read those early discussions.+
- +
-== External Tools ==+
- +
-* [https://bitbucket.org/billcroberts/fixup/overview fixup] : script for converting allow rules to use macros+

Current revision

The content of this page has moved to http://seandroid.bitbucket.org/, please update your bookmarks or links.

Personal tools