mirror of
https://github.com/privacyguides/privacyguides.org.git
synced 2025-10-16 12:42:13 +00:00
Fix some consistency and grammar (#805)
Co-Authored-By: Daniel Gray <dng@disroot.org>
This commit is contained in:
taivlam
@@ -9,7 +9,6 @@ description: |
|
||||
---
|
||||
|
||||
## AOSP Derivatives
|
||||
|
||||
{% for item_hash in site.data.operating-systems.android %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -20,13 +19,10 @@ description: |
|
||||
{% endfor %}
|
||||
|
||||
## Android security and privacy features
|
||||
|
||||
### User Profiles
|
||||
|
||||
Multiple user profiles (Settings → System → Multiple users) are the simplest way to isolate in Android. With user profiles you can limit a user from making calls, SMS or installing apps on the device. Each profile is encrypted using its own encryption key and cannot access the data of any other profiles. Even the device owner cannot view the data of other profiles without knowing their password. Multiple user profiles is a more secure method of isolation.
|
||||
|
||||
### Work Profile
|
||||
|
||||
[Work Profiles](https://support.google.com/work/android/answer/6191949) are another way to isolate individual apps and may be more convenient than separate user profiles.
|
||||
|
||||
A **device controller** such as [Shelter](#recommended-apps) is required, unless you're using CalyxOS which includes one.
|
||||
@@ -36,7 +32,6 @@ The work profile is dependent on a device controller to function. Features such
|
||||
This method is generally less secure than a secondary user profile; however, it does allow you the convenience of running apps in both the work and personal profiles simultaneously.
|
||||
|
||||
### Verified Boot
|
||||
|
||||
[Verified boot](https://source.android.com/security/verifiedboot) is an important part of the Android security model. It provides protection against [Evil maid](https://en.wikipedia.org/wiki/Evil_maid_attack) attacks, malware persistence, and ensures security updates cannot be downgraded with [rollback protection](https://source.android.com/security/verifiedboot/verified-boot#rollback-protection).
|
||||
|
||||
Android 10 and above has moved away from full-disk encryption (FDE) to more flexible [file-based encryption](https://source.android.com/security/encryption/file-based).
|
||||
@@ -46,15 +41,12 @@ Each user's data is encrypted using their own unique encryption key, and the ope
|
||||
Unfortunately, original equipment manufacturers (OEMs) are only obliged to support verified boot on their stock Android distribution. Only a few OEMs such as Google support custom Android Verified Boot (AVB) key enrollment on their devices. Some AOSP derivatives such as LineageOS or /e/ OS do not support verified boot even on hardware with verified boot support for third party operating systems. We recommend that you check for support **before** purchasing a new device. AOSP derivatives which do not support verified boot are **not** recommended.
|
||||
|
||||
### VPN Killswitch
|
||||
|
||||
Android 7 and above supports a VPN killswitch and it is available without the need to install third party apps. This feature can prevent leaks if the VPN is disconnected. It can be found in ⚙️ Settings → Network & internet → VPN → ⚙️ → Block connections without VPN.
|
||||
|
||||
### Global Toggles
|
||||
|
||||
Modern Android devices have global toggles for disabling [Bluetooth](https://en.wikipedia.org/wiki/Bluetooth) and location services. Android 12 introduced toggles for the camera and microphone. When not in use, we recommend disabling these features. Apps cannot use disabled features (even if granted individual permission) until renabled.
|
||||
|
||||
## Recommended Apps
|
||||
|
||||
{% for item_hash in site.data.operating-systems.android-applications %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -65,9 +57,7 @@ Modern Android devices have global toggles for disabling [Bluetooth](https://en.
|
||||
{% endfor %}
|
||||
|
||||
## General Recommendations
|
||||
|
||||
### Avoid Root
|
||||
|
||||
[Rooting](https://en.wikipedia.org/wiki/Rooting_(Android)) Android phones can decrease security significantly as it weakens the complete [Android security model](https://en.wikipedia.org/wiki/Android_(operating_system)#Security_and_privacy). This can decrease privacy should there be an exploit that is assisted by the decreased security. Common rooting methods involve directly tampering with the boot partition, making it impossible to perform successful [verified boot](https://source.android.com/security/verifiedboot). Apps that require root will also modify the system partition meaning that verified boot would have to remain disabled. Having root exposed directly in the user interface also increases the [attack surface](https://en.wikipedia.org/wiki/Attack_surface) of your device and may assist in [privilege escalation](https://en.wikipedia.org/wiki/Privilege_escalation) vulnerabilities and [SELinux](https://en.wikipedia.org/wiki/Security-Enhanced_Linux) policy bypasses.
|
||||
|
||||
Adblockers (AdAway) which modify the <a href="https://en.wikipedia.org/wiki/Hosts_(file)">hosts file</a> and firewalls (AFWall+) which require root access persistently are dangerous and should not be used. They are also not the correct way to solve their intended purposes. For Adblocking we suggest encrypted <a href="/providers/dns/">DNS</a> or <a href="/providers/vpn/">VPN</a> server blocking solutions instead. RethinkDNS, TrackerControl and AdAway in non-root mode will take up the VPN slot (by using a local loopback VPN) preventing you from using privacy enhancing services such as Orbot or a real VPN server.
|
||||
@@ -77,7 +67,6 @@ AFWall+ works based on the <a href="#graphene-calyxos">packet filtering approach
|
||||
We do not believe that the security sacrifices made by rooting a phone are worth the questionable privacy benefits of those apps.
|
||||
|
||||
### Firmware Updates
|
||||
|
||||
Firmware updates are critical for maintaining security and without them your device cannot be secure. Original equipment manufacturers (OEMs)—in other words, phone manufacturers—have support agreements with their partners to provide the closed source components for a limited support period. These are detailed in the monthly [Android Security Bulletins](https://source.android.com/security/bulletin).
|
||||
|
||||
As the components of the phone such as the processor and radio technologies rely on closed source components, the updates must be provided by the respective manufacturers. Therefore it is important that you purchase a device within an active support cycle. [Qualcomm](https://www.qualcomm.com/news/releases/2020/12/16/qualcomm-and-google-announce-collaboration-extend-android-os-support-and) and [Samsung](https://news.samsung.com/us/samsung-galaxy-security-extending-updates-knox/) support their devices for 4 years while cheaper products often have shorter support. With the introduction of the [Pixel 6](https://support.google.com/pixelphone/answer/4457705), Google now makes their own system on chip (SoC) and they will provide 5 years of support.
|
||||
@@ -85,11 +74,9 @@ As the components of the phone such as the processor and radio technologies rely
|
||||
Devices that have reached their end-of-life (EoL) and are no longer supported by the SoC manufacturer, cannot receive firmware updates from OEM vendors or after market Android distributors. This means that security issues with those devices will remain unfixed.
|
||||
|
||||
### Android Versions
|
||||
|
||||
It's important to not use an [end-of-life](https://endoflife.date/android) version of Android. Newer versions of Android not only receive security updates for the operating system but also important privacy enhancing updates too. For example, [prior to Android 10](https://developer.android.com/about/versions/10/privacy/changes), any user apps with the [`READ_PHONE_STATE`](https://developer.android.com/reference/android/Manifest.permission#READ_PHONE_STATE) permission could access sensitive and unique serial numbers of your phone such as [IMEI](https://en.wikipedia.org/wiki/International_Mobile_Equipment_Identity), [MEID](https://en.wikipedia.org/wiki/Mobile_equipment_identifier), your SIM card's [IMSI](https://en.wikipedia.org/wiki/International_mobile_subscriber_identity), whereas now they must be system apps to do so. System apps are only provided by the OEM or Android distribution.
|
||||
|
||||
### Android Permissions
|
||||
|
||||
[Permissions on Android](https://developer.android.com/guide/topics/permissions/overview) grant users control over what apps are allowed to access. Google regularly makes [improvements](https://developer.android.com/about/versions/11/privacy/permissions) on the permission system in each successive version. All user installed apps are strictly [sandboxed](https://source.android.com/security/app-sandbox), therefore there is no need to install any antivirus apps. The savings you make from not purchasing or subscribing to security apps is better spent on paying for a supported device in the future.
|
||||
|
||||
Should you want to run an app that you're unsure about, consider using a user or work [profile](/android/#android-security-privacy).
|
||||
@@ -99,37 +86,34 @@ If you have a Google account we suggest enrolling in the [Advanced Protection Pr
|
||||
|
||||
The Advanced Protection Program provides enhanced threat monitoring and enables:
|
||||
|
||||
* Stricter two factor authentication; e.g. that [U2F](https://en.wikipedia.org/wiki/Universal_2nd_Factor) **must** be used and disallows the use of [SMS OTPs](https://en.wikipedia.org/wiki/One-time_password#SMS), [TOTP](https://en.wikipedia.org/wiki/Time-based_one-time_password), and [OAuth](https://en.wikipedia.org/wiki/OAuth)
|
||||
* Only Google and verified third party apps can access account data
|
||||
* Scanning of incoming emails on Gmail accounts for [phishing](https://en.wikipedia.org/wiki/Phishing#Email_phishing) attempts
|
||||
* Stricter [safe browser scanning](https://www.google.com/chrome/privacy/whitepaper.html#malware) with Google Chrome
|
||||
* Stricter recovery process for accounts with lost credentials
|
||||
* Stricter two factor authentication; e.g. that [U2F](https://en.wikipedia.org/wiki/Universal_2nd_Factor) **must** be used and disallows the use of [SMS OTPs](https://en.wikipedia.org/wiki/One-time_password#SMS), [TOTP](https://en.wikipedia.org/wiki/Time-based_one-time_password), and [OAuth](https://en.wikipedia.org/wiki/OAuth)
|
||||
* Only Google and verified third party apps can access account data
|
||||
* Scanning of incoming emails on Gmail accounts for [phishing](https://en.wikipedia.org/wiki/Phishing#Email_phishing) attempts
|
||||
* Stricter [safe browser scanning](https://www.google.com/chrome/privacy/whitepaper.html#malware) with Google Chrome
|
||||
* Stricter recovery process for accounts with lost credentials
|
||||
|
||||
For users that are using the privileged Google Play Services (common on stock operating systems), the Advanced Protection Program also comes with [additional benefits](https://support.google.com/accounts/answer/9764949?hl=en) such as:
|
||||
* Not allowing app installation outside of the Google Play Store, the OS vendor's app store, or via [`adb`](https://en.wikipedia.org/wiki/Android_Debug_Bridge)
|
||||
* Mandatory automatic device scanning with [Play Protect](https://support.google.com/googleplay/answer/2812853?hl=en#zippy=%2Chow-malware-protection-works%2Chow-privacy-alerts-work)
|
||||
* Warning the user about unverified applications
|
||||
For users that are using the privileged Google Play Services (common on stock operating systems), the Advanced Protection Program also comes with [additional benefits](https://support.google.com/accounts/answer/9764949?hl=en) such as:
|
||||
* Not allowing app installation outside of the Google Play Store, the OS vendor's app store, or via [`adb`](https://en.wikipedia.org/wiki/Android_Debug_Bridge)
|
||||
* Mandatory automatic device scanning with [Play Protect](https://support.google.com/googleplay/answer/2812853?hl=en#zippy=%2Chow-malware-protection-works%2Chow-privacy-alerts-work)
|
||||
* Warning the user about unverified applications
|
||||
|
||||
### SafetyNet and Play Integrity API
|
||||
|
||||
[SafetyNet](https://developer.android.com/training/safetynet/attestation) and the [Play Integrity APIs](https://developer.android.com/google/play/integrity) are generally used for [banking apps](https://grapheneos.org/usage#banking-apps). Many banking apps will work fine in GrapheneOS with sandboxed Play services, however some non-financal apps have their own crude anti-tampering mechanisms which might fail. GrapheneOS passes the `basicIntegrity` check, but not the certification check `ctsProfileMatch`. Devices with Android 8 or later have hardware attestation support which cannot be bypassed without leaked keys or serious vulnerabilities.
|
||||
|
||||
As for Google Wallet, we don't recommend this due to their [privacy policy](https://payments.google.com/payments/apis-secure/get_legal_document?ldo=0&ldt=privacynotice&ldl=en), which states you must opt-out if you don't want your credit rating and personal information shared with affiliate marketing services.
|
||||
|
||||
### Advertising ID
|
||||
|
||||
All devices with Google Play Services installed automatically generate an [advertising ID](https://support.google.com/googleplay/android-developer/answer/6048248?hl=en) used for targeted advertising. Disable this feature to limit the data collected about you.
|
||||
|
||||
On Android distributions with [Sandboxed Google Play](https://grapheneos.org/usage#sandboxed-google-play), go to ⚙️ Settings → Apps → Sandboxed Google Play → Google Settings → Ads and select **Delete advertising ID**.
|
||||
|
||||
On Android distributions with privileged Google Play Services (such as stock OSes), the setting may be in one of several locations. Check
|
||||
* ⚙️ Settings → Google → Ads
|
||||
* ⚙️ Settings → Privacy → Ads
|
||||
* ⚙️ Settings → Google → Ads
|
||||
* ⚙️ Settings → Privacy → Ads
|
||||
|
||||
Depending on your system, you will either be given the option to delete your advertising ID or to "Opt out of interest-based ads". You should delete the advertising ID if you are given the option to, and if you are not, we recommend that you opt out of interested-based ads and then reset your advertising ID.
|
||||
|
||||
### Android Device Shopping
|
||||
|
||||
Google Pixels are known to have good security and properly support [verified boot](https://source.android.com/security/verifiedboot). Some other phones such as the Fairphone and Oneplus devices also support custom Android verified boot (AVB) key enrollment. However, there have been issues with their older models. In the past they were using [test keys](https://social.coop/@dazinism/105346943304083054) or not doing proper verification, making verified boot on those devices useless.
|
||||
|
||||
Avoid buying phones from mobile network operators. These often have a **locked bootloader** and do not support [OEM unlocking](https://source.android.com/devices/bootloader/locking_unlocking). These phone variants will prevent you from installing any kind of alternative Android distribution. Phones that cannot be unlocked will often have an [IMEI](https://en.wikipedia.org/wiki/International_Mobile_Equipment_Identity) starting with "35", that includes phones from purchased from Verizon, Telus, Rogers, EE etc.
|
||||
@@ -138,13 +122,13 @@ Be very **careful** about buying second hand phones from online marketplaces. Al
|
||||
|
||||
We have these general tips:
|
||||
|
||||
* If you're after a bargain on a Pixel device, we suggest buying an "**a**" model, just after the next flagship is released. Discounts are usually available because Google will be trying to clear their stock.
|
||||
* Consider price beating options and specials offered at [brick and mortar](https://en.wikipedia.org/wiki/Brick_and_mortar) stores.
|
||||
* Look at online community bargain sites in your country. These can alert you to good sales.
|
||||
* The price per day for a device can be calculated as \\({\\text {EoL Date}-\\text{Current Date} \\over \\text{Cost}}\\). Google provides a [list](https://support.google.com/nexus/answer/4457705) of their supported devices.
|
||||
* Do not buy devices that have reached or are near their end-of-life, additional firmware updates must be provided by the manufacturer.
|
||||
* Do not buy preloaded LineageOS or /e/ OS phones or any Android phones without proper [verified boot](https://source.android.com/security/verifiedboot) support and firmware updates. These devices also have no way for you to check whether they've been tampered with.
|
||||
* In short, if a device or Android distribution is not listed here, there is probably a good reason, so check our [discussions](https://github.com/privacyguides/privacyguides.org/discussions) page.
|
||||
* If you're after a bargain on a Pixel device, we suggest buying an "**a**" model, just after the next flagship is released. Discounts are usually available because Google will be trying to clear their stock.
|
||||
* Consider price beating options and specials offered at [brick and mortar](https://en.wikipedia.org/wiki/Brick_and_mortar) stores.
|
||||
* Look at online community bargain sites in your country. These can alert you to good sales.
|
||||
* The price per day for a device can be calculated as \\({\\text {EoL Date}-\\text{Current Date} \\over \\text{Cost}}\\). Google provides a [list](https://support.google.com/nexus/answer/4457705) of their supported devices.
|
||||
* Do not buy devices that have reached or are near their end-of-life, additional firmware updates must be provided by the manufacturer.
|
||||
* Do not buy preloaded LineageOS or /e/ OS phones or any Android phones without proper [verified boot](https://source.android.com/security/verifiedboot) support and firmware updates. These devices also have no way for you to check whether they've been tampered with.
|
||||
* In short, if a device or Android distribution is not listed here, there is probably a good reason, so check our [discussions](https://github.com/privacyguides/privacyguides.org/discussions) page.
|
||||
|
||||
The installation of GrapheneOS on a Pixel phone is easy with their [web installer](https://grapheneos.org/install/web). If you don't feel comfortable doing it yourself and are willing to spend a bit of extra money, check out the [NitroPhone](https://shop.nitrokey.com/shop) as they come preloaded with GrapheneOS from the reputable [Nitrokey](https://www.nitrokey.com/about) company. The GrapheneOS project is not currently affiliated with any vendor and cannot ensure the quality or security of their products.
|
||||
|
||||
@@ -171,26 +155,22 @@ To mitigate these problems, we recommend [Droidify](https://github.com/Iamlooker
|
||||
{% endfor %}
|
||||
|
||||
#### Where to get your applications
|
||||
|
||||
Sometimes the official F-Droid repository may fall behind on updates. F-Droid maintainers reuse package ids while signing apps with their own keys, which is not ideal as it does give the F-Droid team ultimate trust. The Google Play version of some apps may contain unwanted telemetry or lack features that are available in the F-Droid version. The Google Play Store requires a Google account to login which is not great for privacy. The [Aurora Store](https://auroraoss.com/download/AuroraStore/) (a Google Play Store proxy) does not always work, though it does most of the time.
|
||||
|
||||
We have these general tips:
|
||||
* Check if the app developers have their own F-Droid repository first eg. [Bitwarden](https://bitwarden.com/), [Samourai Wallet](https://www.samouraiwallet.com/), or [Newpipe](https://newpipe.net/), have their own repositories with either less telemetry, additional features or faster updates. This is the ideal situation and you should be using these repositories if possible.
|
||||
* Check if an app is available on the [IzzyOnDroid](https://apt.izzysoft.de/fdroid/) repository. The IzzyOnDroid repository pulls builds directly from GitHub and is the next best thing to the developers' own repositories. We recommend that you download the GitHub builds and install them manually first, then use IzzyOnDroid for any subsequent updates. This will ensure that the signature of the applications you get from IzzyOnDroid matches that of the developer and the packages have not been tampered with.
|
||||
* Check if there are any differences between the F-Droid version and the Google Play Store version. Some applications like [IVPN](https://www.ivpn.net/) do not include certain features (eg [AntiTracker](https://www.ivpn.net/knowledgebase/general/antitracker-faq/)) in their Google Play Store build out of fear of censorship by Google.
|
||||
* Check if the app developers have their own F-Droid repository first eg. [Bitwarden](https://bitwarden.com/), [Samourai Wallet](https://www.samouraiwallet.com/), or [Newpipe](https://newpipe.net/), have their own repositories with either less telemetry, additional features or faster updates. This is the ideal situation and you should be using these repositories if possible.
|
||||
* Check if an app is available on the [IzzyOnDroid](https://apt.izzysoft.de/fdroid/) repository. The IzzyOnDroid repository pulls builds directly from GitHub and is the next best thing to the developers' own repositories. We recommend that you download the GitHub builds and install them manually first, then use IzzyOnDroid for any subsequent updates. This will ensure that the signature of the applications you get from IzzyOnDroid matches that of the developer and the packages have not been tampered with.
|
||||
* Check if there are any differences between the F-Droid version and the Google Play Store version. Some applications like [IVPN](https://www.ivpn.net/) do not include certain features (eg [AntiTracker](https://www.ivpn.net/knowledgebase/general/antitracker-faq/)) in their Google Play Store build out of fear of censorship by Google.
|
||||
|
||||
Evaluate whether the additional features in the F-Droid build are worth the slower updates. Also think about whether faster updates from the Google Play Store are worth the potential privacy isues in your [threat model](/threat-modeling/).
|
||||
|
||||
## Security comparison of GrapheneOS and CalyxOS
|
||||
|
||||
### Profiles
|
||||
|
||||
CalyxOS includes a device controller app so there is no need to install a third party app like [Shelter](/android/#recommended-apps). GrapheneOS plans to introduce nested profile support with better isolation in the future.
|
||||
|
||||
GrapheneOS extends the [user profile](/android/#android-security-privacy) feature allowing a user to press an "End Session" button. This button clears the encryption key from memory. There are plans to add a [cross profile notifications system](https://github.com/GrapheneOS/os-issue-tracker/issues/88) in the future.
|
||||
|
||||
### Sandboxed Google Play vs Privileged MicroG
|
||||
|
||||
When Google Play services are used on GrapheneOS, they run as a user app and are contained within a user or work profile.
|
||||
|
||||
Sandboxed Google Play is confined using the highly restrictive, default [`untrusted_app`](https://source.android.com/security/selinux/concepts) domain provided by [SELinux](https://en.wikipedia.org/wiki/Security-Enhanced_Linux). Permissions for apps to use Google Play Services can be revoked at any time by the user.
|
||||
@@ -200,7 +180,6 @@ MicroG is a reimplementation of Google Play Services. This means it needs to be
|
||||
From a usability point of view, Sandboxed Google Play also works well with far more applications than MicroG, thanks to its support for services like [Google Play Games](https://play.google.com/googleplaygames) and [In-app Billing API](https://android-doc.github.io/google/play/billing/api.html).
|
||||
|
||||
### Privileged App Extensions
|
||||
|
||||
Android 12 comes with special support for seamless app updates with [third party app stores](https://android-developers.googleblog.com/2020/09/listening-to-developer-feedback-to.html). The popular Free and Open Source Software (FOSS) repository [F-Droid](https://f-droid.org) doesn't implement this feature and requires a [privileged extension](https://f-droid.org/en/packages/org.fdroid.fdroid.privileged) to be included with the Android distribution in order to have unattended app installation.
|
||||
|
||||
GrapheneOS doesn't compromise on security; therefore, they do not include the F-Droid extension. Users have to confirm all updates manually if they want to use F-Droid. Alternatively, they can use the Droidify client which does support seamless app updates in Android 12. GrapheneOS officially recommends [Sandboxed Google Play](https://grapheneos.org/usage#sandboxed-google-play) instead. Many FOSS Android apps are also in Google Play but sometimes they are not (like [NewPipe]({% link _evergreen/video-streaming.md %})).
|
||||
@@ -208,12 +187,11 @@ GrapheneOS doesn't compromise on security; therefore, they do not include the F-
|
||||
CalyxOS includes the [privileged extension](https://f-droid.org/en/packages/org.fdroid.fdroid.privileged), which may lower device security. Seamless app updates should be possible with [Aurora Store](https://auroraoss.com) in Android 12.
|
||||
|
||||
### Additional hardening
|
||||
|
||||
GrapheneOS improves upon [AOSP](https://source.android.com/) security with:
|
||||
|
||||
* **Hardened WebView:** Vanadium WebView requires [64-bit](https://en.wikipedia.org/wiki/64-bit_computing) processes on the [WebView](https://developer.android.com/reference/android/webkit/WebView) process and disables legacy [32-bit](https://en.wikipedia.org/wiki/32-bit_computing) processes. It uses hardened compiler options such as [`-fwrapv`](https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html) and [`-fstack-protector-strong`](https://gcc.gnu.org/onlinedocs/gcc-4.9.3/gcc/Optimize-Options.html), which can help protect against [stack buffer overflows](https://en.wikipedia.org/wiki/Stack_buffer_overflow). [API](https://en.wikipedia.org/wiki/API)s such as the [battery status API](https://chromestatus.com/feature/4537134732017664) are disabled for privacy reasons. All system apps on GrapheneOS use the Vanadium WebView which means user installed apps that use WebView will also benefit from Vanadium's hardening. The [Vanadium patch set](https://github.com/GrapheneOS/Vanadium/tree/12/patches) is a lot more comprehensive than CalyxOS's [Chromium patch set](https://gitlab.com/CalyxOS/chromium-patches) which is derived from it.
|
||||
* **Hardened Kernel:** GrapheneOS kernel includes some hardening from the [linux-hardened](https://github.com/GrapheneOS/linux-hardened) project and the [Kernel Self Protection Project (KSPP)](https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project). CalyxOS uses the [same kernel](https://calyxos.org/docs/development/build/kernel/) as regular Android with some minor modifications.
|
||||
* **Hardened Memory Allocator:** GrapheneOS uses the [hardened malloc](https://github.com/GrapheneOS/hardened_malloc) subproject as its memory allocator. This focuses on hardening against [memory heap corruption](https://en.wikipedia.org/wiki/Memory_corruption). CalyxOS uses the default AOSP [Scudo Malloc](https://source.android.com/devices/tech/debug/scudo), which is generally [less effective](https://twitter.com/danielmicay/status/1033671709197398016). Hardened Malloc has uncovered vulnerabilities in AOSP which have been [fixed](https://github.com/GrapheneOS/platform_system_core/commit/be11b59725aa6118b0e1f0712572e835c3d50746) by GrapheneOS such as [CVE-2021-0703](https://nvd.nist.gov/vuln/detail/CVE-2021-0703).
|
||||
* **Secure Exec Spawning:** GrapheneOS [spawns](https://en.wikipedia.org/wiki/Spawn_(computing)) fresh processes as opposed to using the [Zygote model](https://ayusch.com/android-internals-the-android-os-boot-process) used by AOSP and CalyxOS. The Zygote model weakens [Address Space Layout Randomization](https://en.wikipedia.org/wiki/Address_space_layout_randomization) (ASLR) and is considered [less secure](https://wenke.gtisc.gatech.edu/papers/morula.pdf). Creating [fresh processes](https://grapheneos.org/usage#exec-spawning) is safer but will have some performance penalty when launching a new application. These penalties are not really noticeable unless you have an [old device](https://support.google.com/nexus/answer/4457705) with slow storage such as the Pixel 3a/3a XL as it has [eMMC](https://en.wikipedia.org/wiki/MultiMediaCard#eMMC).
|
||||
* **Hardened WebView:** Vanadium WebView requires [64-bit](https://en.wikipedia.org/wiki/64-bit_computing) processes on the [WebView](https://developer.android.com/reference/android/webkit/WebView) process and disables legacy [32-bit](https://en.wikipedia.org/wiki/32-bit_computing) processes. It uses hardened compiler options such as [`-fwrapv`](https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html) and [`-fstack-protector-strong`](https://gcc.gnu.org/onlinedocs/gcc-4.9.3/gcc/Optimize-Options.html), which can help protect against [stack buffer overflows](https://en.wikipedia.org/wiki/Stack_buffer_overflow). [API](https://en.wikipedia.org/wiki/API)s such as the [battery status API](https://chromestatus.com/feature/4537134732017664) are disabled for privacy reasons. All system apps on GrapheneOS use the Vanadium WebView which means user installed apps that use WebView will also benefit from Vanadium's hardening. The [Vanadium patch set](https://github.com/GrapheneOS/Vanadium/tree/12/patches) is a lot more comprehensive than CalyxOS's [Chromium patch set](https://gitlab.com/CalyxOS/chromium-patches) which is derived from it.
|
||||
* **Hardened Kernel:** GrapheneOS kernel includes some hardening from the [linux-hardened](https://github.com/GrapheneOS/linux-hardened) project and the [Kernel Self Protection Project (KSPP)](https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project). CalyxOS uses the [same kernel](https://calyxos.org/docs/development/build/kernel/) as regular Android with some minor modifications.
|
||||
* **Hardened Memory Allocator:** GrapheneOS uses the [hardened malloc](https://github.com/GrapheneOS/hardened_malloc) subproject as its memory allocator. This focuses on hardening against [memory heap corruption](https://en.wikipedia.org/wiki/Memory_corruption). CalyxOS uses the default AOSP [Scudo Malloc](https://source.android.com/devices/tech/debug/scudo), which is generally [less effective](https://twitter.com/danielmicay/status/1033671709197398016). Hardened Malloc has uncovered vulnerabilities in AOSP which have been [fixed](https://github.com/GrapheneOS/platform_system_core/commit/be11b59725aa6118b0e1f0712572e835c3d50746) by GrapheneOS such as [CVE-2021-0703](https://nvd.nist.gov/vuln/detail/CVE-2021-0703).
|
||||
* **Secure Exec Spawning:** GrapheneOS [spawns](https://en.wikipedia.org/wiki/Spawn_(computing)) fresh processes as opposed to using the [Zygote model](https://ayusch.com/android-internals-the-android-os-boot-process) used by AOSP and CalyxOS. The Zygote model weakens [Address Space Layout Randomization](https://en.wikipedia.org/wiki/Address_space_layout_randomization) (ASLR) and is considered [less secure](https://wenke.gtisc.gatech.edu/papers/morula.pdf). Creating [fresh processes](https://grapheneos.org/usage#exec-spawning) is safer but will have some performance penalty when launching a new application. These penalties are not really noticeable unless you have an [old device](https://support.google.com/nexus/answer/4457705) with slow storage such as the Pixel 3a/3a XL as it has [eMMC](https://en.wikipedia.org/wiki/MultiMediaCard#eMMC).
|
||||
|
||||
**Please note that these are just a few examples and are not an extensive list of GrapheneOS's hardening**. For a more complete list, please read GrapheneOS' [official documentation](https://grapheneos.org/features).
|
||||
|
||||
@@ -6,7 +6,6 @@ description: |
|
||||
---
|
||||
|
||||
## General Recommendations
|
||||
|
||||
{% for item_hash in site.data.software.browsers %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -17,7 +16,6 @@ description: |
|
||||
{% endfor %}
|
||||
|
||||
## Desktop Browser Recommendations
|
||||
|
||||
{% for item_hash in site.data.software.browsers-desktop %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -28,7 +26,6 @@ description: |
|
||||
{% endfor %}
|
||||
|
||||
## Mobile Browser Recommendations
|
||||
|
||||
On Android, Mozilla's engine [GeckoView](https://mozilla.github.io/geckoview/) has yet to support [site isolation](https://hacks.mozilla.org/2021/05/introducing-firefox-new-site-isolation-security-architecture) or enable [isolatedProcess](https://bugzilla.mozilla.org/show_bug.cgi?id=1565196). Firefox on Android also doesn't yet have [HTTPS-Only mode](https://github.com/mozilla-mobile/fenix/issues/16952#issuecomment-907960218) built-in. We do not recommend Firefox or any Gecko based browsers at this time.
|
||||
|
||||
On iOS all web browsers use [WKWebView](https://developer.apple.com/documentation/webkit/wkwebview), so all browsers on the App Store are essentially Safari under the hood.
|
||||
@@ -43,7 +40,6 @@ On iOS all web browsers use [WKWebView](https://developer.apple.com/documentatio
|
||||
{% endfor %}
|
||||
|
||||
## Additional Resources
|
||||
|
||||
{% for item_hash in site.data.software.browsers-resources %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
|
||||
@@ -7,7 +7,6 @@ description: |
|
||||
---
|
||||
|
||||
## Traditional distributions
|
||||
|
||||
{% for item_hash in site.data.operating-systems.linux-desktop %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -18,7 +17,6 @@ description: |
|
||||
{% endfor %}
|
||||
|
||||
## Immutable distributions
|
||||
|
||||
{% for item_hash in site.data.operating-systems.linux-desktop-immutable %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -29,7 +27,6 @@ description: |
|
||||
{% endfor %}
|
||||
|
||||
## Anonymity-focused distributions
|
||||
|
||||
{% for item_hash in site.data.operating-systems.linux-desktop-tor %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -40,12 +37,11 @@ description: |
|
||||
{% endfor %}
|
||||
|
||||
## GNU/Linux
|
||||
|
||||
It is often believed that [open source](https://en.wikipedia.org/wiki/Open-source_software) software is inherently secure because the source code is available. There is an expectation that community verification occurs regularly; however, this isn't always [the case](https://seirdy.one/2022/02/02/floss-security.html). It does depend on a number of factors, such as project activity, developer experience, level of rigour applied to [code reviews](https://en.wikipedia.org/wiki/Code_review), and how often attention is given to specific parts of the [codebase](https://en.wikipedia.org/wiki/Codebase) that may go untouched for years.
|
||||
|
||||
At the moment, desktop GNU/Linux does have some areas that could be better improved when compared to their proprietary counterparts, e.g:
|
||||
|
||||
* A verified boot chain, unlike Apple's [Secure Boot](https://support.apple.com/guide/security/startup-security-utility-secc7b34e5b5/web) (with [Secure Enclave](https://support.apple.com/guide/security/secure-enclave-sec59b0b31ff/1/web/1)), Android's [Verified Boot](https://source.android.com/security/verifiedboot) or Microsoft Windows's [boot process](https://docs.microsoft.com/en-us/windows/security/information-protection/secure-the-windows-10-boot-process) with [TPM](https://docs.microsoft.com/en-us/windows/security/information-protection/tpm/how-windows-uses-the-tpm). These features and hardware technologies can all help prevent persistant tampering by malware or [evil maid attacks](https://en.wikipedia.org/wiki/Evil_Maid_attack)
|
||||
* A verified boot chain, unlike Apple's [Secure Boot](https://support.apple.com/guide/security/startup-security-utility-secc7b34e5b5/web) (with [Secure Enclave](https://support.apple.com/guide/security/secure-enclave-sec59b0b31ff/1/web/1)), Android's [Verified Boot](https://source.android.com/security/verifiedboot) or Microsoft Windows's [boot process](https://docs.microsoft.com/en-us/windows/security/information-protection/secure-the-windows-10-boot-process) with [TPM](https://docs.microsoft.com/en-us/windows/security/information-protection/tpm/how-windows-uses-the-tpm). These features and hardware technologies can all help prevent persistent tampering by malware or [evil maid attacks](https://en.wikipedia.org/wiki/Evil_Maid_attack)
|
||||
* Strong sandboxing solution such as that found in [MacOS](https://developer.apple.com/library/archive/documentation/Security/Conceptual/AppSandboxDesignGuide/AboutAppSandbox/AboutAppSandbox.html), [ChromeOS](https://chromium.googlesource.com/chromiumos/docs/+/HEAD/sandboxing.md), and [Android](https://source.android.com/security/app-sandbox). Commonly used Linux sandboxing solutions such as [Flatpak](https://docs.flatpak.org/en/latest/sandbox-permissions.html) and [Firejail](https://firejail.wordpress.com/) still have a long way to go
|
||||
* Strong [exploit mitigations](https://madaidans-insecurities.github.io/linux.html#exploit-mitigations)
|
||||
|
||||
@@ -60,7 +56,7 @@ This page uses the term "Linux" to describe desktop GNU/Linux distributions. Oth
|
||||
### Release cycle
|
||||
We highly recommend that you choose distributions which stay close to the stable upstream software releases. This is because frozen release cycle distributions often don't update package versions and fall behind on security updates.
|
||||
|
||||
For frozen distributions, package maintainers are expected to backport patches to fix vulnerabilities (Debian is one such [example](https://www.debian.org/security/faq#handling)) rather than bump the software to the "next version" released by the upstream developer. Some security fixes [do not](https://arxiv.org/abs/2105.14565) recieve a [CVE](https://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures) (particularly less popular software) at all and therefore do not make it into the distribution with this patching model. As a result minor security fixes are sometimes held back until the next major release.
|
||||
For frozen distributions, package maintainers are expected to backport patches to fix vulnerabilities (Debian is one such [example](https://www.debian.org/security/faq#handling)) rather than bump the software to the "next version" released by the upstream developer. Some security fixes [do not](https://arxiv.org/abs/2105.14565) receive a [CVE](https://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures) (particularly less popular software) at all and therefore do not make it into the distribution with this patching model. As a result minor security fixes are sometimes held back until the next major release.
|
||||
|
||||
We don't believe holding packages back and applying interim patches is a good idea, as it diverges from the way the developer might have intended the software to work. [Richard Brown](https://rootco.de/aboutme/) has a presentation about this:
|
||||
|
||||
@@ -93,7 +89,6 @@ The Atomic update method is used for immutable distributions like Silverblue, Tu
|
||||
There is often some confusion about "security-focused" distributions and "pentesting" distributions. A quick search for "the most secure Linux distribution" will often give results like Kali Linux, Black Arch, and Parrot OS. These distributions are offensive penetration testing distributions that bundle tools for testing other systems. They don't include any "extra security" or defensive mitigations intended for regular use.
|
||||
|
||||
### Arch-based distributions
|
||||
|
||||
Arch based distributions are not recommended for new users, regardless of the distribution. Arch does not have an distribution update mechanism for the underlying software choices. As a result the user of the system must stay aware with current trends and adopt technologies as they supersede older practices.
|
||||
|
||||
For a secure system, the user is also expected to have sufficient Linux knowledge to properly set up security for their system such as adopting a [mandatory access control](https://en.wikipedia.org/wiki/Mandatory_access_control) system, setting up [kernel module](https://en.wikipedia.org/wiki/Loadable_kernel_module#Security) blacklists, hardening boot parameters, manipulating [sysctl](https://en.wikipedia.org/wiki/Sysctl) parameters, and knowing what components they need such as [Polkit](https://en.wikipedia.org/wiki/Polkit).
|
||||
@@ -109,9 +104,7 @@ For advanced users, we only recommend Arch Linux, not any of its derivatives. We
|
||||
We strongly recommend **against** using the Linux-libre kernel, since it [removes security mitigations](https://www.phoronix.com/scan.php?page=news_item&px=GNU-Linux-Libre-5.7-Released) and [suppresses kernel warnings](https://news.ycombinator.com/item?id=29674846) about vulnerable microcode for ideological reasons.
|
||||
|
||||
## General Recommendations
|
||||
|
||||
### Drive Encryption
|
||||
|
||||
Most Linux distributions have an installer option for enabling [Linux Unified Key Setup (LUKS)](https://en.wikipedia.org/wiki/Linux_Unified_Key_Setup) encryption upon installation.
|
||||
|
||||
If this option isn't set at installation time, the user will have to backup their data and re-install, as encryption is applied after [disk partitioning](https://en.wikipedia.org/wiki/Disk_partitioning) but before [file systems](https://en.wikipedia.org/wiki/File_system) are [formatted](https://en.wikipedia.org/wiki/Disk_formatting).
|
||||
@@ -119,11 +112,9 @@ If this option isn't set at installation time, the user will have to backup thei
|
||||
When securely erasing storage devices such as a [Solid-state drive (SSD)](https://en.wikipedia.org/wiki/Solid-state_drive) you should use the [ATA Secure Erase](https://ata.wiki.kernel.org/index.php/ATA_Secure_Erase) command. This command can be issued from your UEFI setup. If the storage device is a regular [hard drive](https://en.wikipedia.org/wiki/Hard_disk_drive), consider using [`nwipe`](https://en.wikipedia.org/wiki/Nwipe).
|
||||
|
||||
### Swap
|
||||
|
||||
Consider using [ZRAM](https://wiki.archlinux.org/title/Swap#zram-generator) or [encrypted swap](https://wiki.archlinux.org/title/Dm-crypt/Swap_encryption) instead of unencrypted swap to avoid potential security issues with sensitive data being pushed to [swap space](https://en.wikipedia.org/wiki/Memory_paging). Fedora based distributions [use ZRAM](https://fedoraproject.org/wiki/Changes/SwapOnZRAM) by default.
|
||||
|
||||
### Wayland
|
||||
|
||||
We recommend using a desktop environment that supports the [Wayland](https://en.wikipedia.org/wiki/Wayland_(display_server_protocol)) display protocol as it developed with security [in mind](https://lwn.net/Articles/589147/). Its predecessor, [X11](https://en.wikipedia.org/wiki/X_Window_System), does not support GUI isolation, allowing all windows to [record screen, log and inject inputs in other windows](https://blog.invisiblethings.org/2011/04/23/linux-security-circus-on-gui-isolation.html), making any attempt at sandboxing futile. While there are options to do nested X11 such as [Xpra](https://en.wikipedia.org/wiki/Xpra) or [Xephyr](https://en.wikipedia.org/wiki/Xephyr), they often come with negative performance consequences and are not convenient to set up and are not preferable over Wayland.
|
||||
|
||||
Fortunately, common environments such as [GNOME](https://www.gnome.org), [KDE](https://kde.org), and the window manager [Sway](https://swaywm.org) have support for Wayland. Some distributions like Fedora and Tumbleweed use it by default and some others may do so in the future as X11 is in [hard maintenance mode](https://www.phoronix.com/scan.php?page=news_item&px=X.Org-Maintenance-Mode-Quickly). If you're using one of those environments it is as easy as selecting the "Wayland" session at the desktop display manager ([GDM](https://en.wikipedia.org/wiki/GNOME_Display_Manager), [SDDM](https://en.wikipedia.org/wiki/Simple_Desktop_Display_Manager)).
|
||||
@@ -136,10 +127,8 @@ Linux distributions such as those which are [Linux-libre](https://en.wikipedia.o
|
||||
We **highly recommend** that you install the microcode updates, as your CPU is already running the proprietary microcode from the factory. Fedora and openSUSE both have the microcode updates applied by default.
|
||||
|
||||
## Privacy tweaks
|
||||
|
||||
### MAC address randomization
|
||||
|
||||
Many desktop linux distributions (Fedora, openSUSE etc) will come with [NetworkManager](https://en.wikipedia.org/wiki/NetworkManager), to configure ethernet and WiFi settings.
|
||||
Many desktop Linux distributions (Fedora, openSUSE etc) will come with [NetworkManager](https://en.wikipedia.org/wiki/NetworkManager), to configure Ethernet and WiFi settings.
|
||||
|
||||
It is possible to [randomize](https://fedoramagazine.org/randomize-mac-address-nm/) the [MAC address](https://en.wikipedia.org/wiki/MAC_address) when using NetworkManager. This provides a bit more privacy on WiFi networks as it makes it harder to track specific devices on the network you're connected to. It does [**not**](https://papers.mathyvanhoef.com/wisec2016.pdf) make you anonymous.
|
||||
|
||||
@@ -147,43 +136,40 @@ We recommend changing the setting to **random** instead of **stable**, as sugges
|
||||
|
||||
If you are using [systemd-networkd](https://en.wikipedia.org/wiki/Systemd#Ancillary_components), you will need to set [`MACAddressPolicy=random`](https://www.freedesktop.org/software/systemd/man/systemd.link.html#MACAddressPolicy=) which will enable [RFC 7844 (Anonymity Profiles for DHCP Clients)](https://www.freedesktop.org/software/systemd/man/systemd.network.html#Anonymize=).
|
||||
|
||||
There isn't much point in randomizing the MAC address for ethernet connections as a system administrator can find you by looking at the port you are using on the [network switch](https://en.wikipedia.org/wiki/Network_switch). Randomizing WiFi MAC addresses depends on support from the WiFi's firmware.
|
||||
There isn't much point in randomizing the MAC address for Ethernet connections as a system administrator can find you by looking at the port you are using on the [network switch](https://en.wikipedia.org/wiki/Network_switch). Randomizing WiFi MAC addresses depends on support from the WiFi's firmware.
|
||||
|
||||
### Other identifiers
|
||||
|
||||
There are other system [identifiers](https://madaidans-insecurities.github.io/guides/linux-hardening.html#identifiers) which you may wish to be careful about. You should give this some thought to see if it applies to your [threat model](/threat-modeling):
|
||||
|
||||
* [10.1 Hostnames and usernames](https://madaidans-insecurities.github.io/guides/linux-hardening.html#hostnames)
|
||||
* [10.2 Timezones / Locales / Keymaps](https://madaidans-insecurities.github.io/guides/linux-hardening.html#timezones-locales-keymaps)
|
||||
* [10.2 Time zones / Locales / Keymaps](https://madaidans-insecurities.github.io/guides/linux-hardening.html#timezones-locales-keymaps)
|
||||
* [10.3 Machine ID](https://madaidans-insecurities.github.io/guides/linux-hardening.html#machine-id)
|
||||
|
||||
### System counting
|
||||
The Fedora Project [counts](https://fedoraproject.org/wiki/Changes/DNF_Better_Counting) how many unique systems access its mirrors by using a [`countme`](https://fedoraproject.org/wiki/Changes/DNF_Better_Counting#Detailed_Description) variable instead of a unique ID. Fedora does this to determine load and provision better servers for updates where necessary.
|
||||
|
||||
The Fedora project [counts](https://fedoraproject.org/wiki/Changes/DNF_Better_Counting) how many unique systems access its mirrors by using an ID on the system access its mirrors by counting using an ID on the system. They do this to determine load and provision better servers for updates where necessary.
|
||||
|
||||
This [option](https://dnf.readthedocs.io/en/latest/conf_ref.html#options-for-both-main-and-repo) appears to be off by default. We recommend adding `countme=false` to `/etc/dnf/dnf.conf` just in case it is enabled in the future. On systems that use `rpm-ostree` such as Silverblue, the countme option is disabled by masking the [rpm-ostree-countme](https://fedoramagazine.org/getting-better-at-counting-rpm-ostree-based-systems/) timer.
|
||||
This [option](https://dnf.readthedocs.io/en/latest/conf_ref.html#options-for-both-main-and-repo) is currently off by default. We recommend adding `countme=false` to `/etc/dnf/dnf.conf` just in case it is enabled in the future. On systems that use `rpm-ostree` such as Silverblue, the countme option is disabled by masking the [rpm-ostree-countme](https://fedoramagazine.org/getting-better-at-counting-rpm-ostree-based-systems/) timer.
|
||||
|
||||
openSUSE also uses a [unique ID](https://en.opensuse.org/openSUSE:Statistics) to count systems, which can be disabled by deleting the `/var/lib/zypp/AnonymousUniqueId` file.
|
||||
|
||||
## Sandboxing and Application confinement
|
||||
|
||||
Some sandboxing solutions for desktop Linux distributions do exist, however they are not as strict as those found in MacOS or ChromeOS. Applications installed from the package manager (`dnf`, `apt`, etc.) typically have **no** sandboxing or confinement whatsoever. Below are a few projects that aim to solve this problem:
|
||||
|
||||
### Flatpak
|
||||
[Flatpak](https://flatpak.org) aims to be a universal package manager for Linux. One of its main goals is to provide a universal package format which can be used in most Linux distributions. It provides some [permission control](https://docs.flatpak.org/en/latest/sandbox-permissions.html). Madaidan [points out](https://madaidans-insecurities.github.io/linux.html#flatpak) that Flatpak sandboxing could be improved as particular Flatpaks often have greater permission than required.
|
||||
There does seem to be [some agreement](https://theevilskeleton.gitlab.io/2021/02/11/response-to-flatkill-org.html) that this is the case.
|
||||
|
||||
Users can restrict applications further by issuing [flatpak overrides](https://docs.flatpak.org/en/latest/flatpak-command-reference.html#flatpak-override). This can be done with the commandline or by using [Flatseal](https://flathub.org/apps/details/com.github.tchx84.Flatseal). Some sample overrides are provided by [tommytran732](https://github.com/tommytran732/Flatpak-Overrides) and [rusty-snake](https://github.com/rusty-snake/kyst/tree/main/flatpak).
|
||||
Users can restrict applications further by issuing [Flatpak overrides](https://docs.flatpak.org/en/latest/flatpak-command-reference.html#flatpak-override). This can be done with the command-line or by using [Flatseal](https://flathub.org/apps/details/com.github.tchx84.Flatseal). Some sample overrides are provided by [tommytran732](https://github.com/tommytran732/Flatpak-Overrides) and [rusty-snake](https://github.com/rusty-snake/kyst/tree/main/flatpak).
|
||||
|
||||
We generally recommend revoking access to:
|
||||
|
||||
* the Network (`share=network`) socket (internet access)
|
||||
* the pulse audio socket (for both audio in and out), `device=all` (access to all devices including the camera)
|
||||
* the PulseAudio socket (for both audio in and out), `device=all` (access to all devices including the camera)
|
||||
* `org.freedesktop.secrets` dbus (access to secrets stored on your keychain) for applications which do not need it
|
||||
|
||||
If an application works natively with Wayland (and not running through the [XWayland](https://wayland.freedesktop.org/xserver.html) compatibility layer), consider revoking its access to the X11 (`socket=x11`) and [Inter-process communications (IPC)](https://en.wikipedia.org/wiki/Unix_domain_socket) socket (`share=ipc`) as well.
|
||||
|
||||
We also recommend restricting broad filesystem permissions such as `filesystem=home` and `filesystem=host` which should be revoked and replaced with just the directories that the app needs to access. Some applications like [VLC](https://www.flathub.org/apps/details/org.videolan.VLC) implement the [Portals](https://docs.flatpak.org/en/latest/portal-api-reference.html) [API](https://en.wikipedia.org/wiki/API), which allows a file manager to pass files to the flatpak application (e.g. VLC) without direct filesystem access privileges. Security is increased because VLC is only able to access the specific file that the user wants to open, rather than any file at any time the application is open.
|
||||
We also recommend restricting broad filesystem permissions such as `filesystem=home` and `filesystem=host` which should be revoked and replaced with just the directories that the app needs to access. Some applications like [VLC](https://www.flathub.org/apps/details/org.videolan.VLC) implement the [Portals](https://docs.flatpak.org/en/latest/portal-api-reference.html) [API](https://en.wikipedia.org/wiki/API), which allows a file manager to pass files to the Flatpak application (e.g. VLC) without direct filesystem access privileges. Security is increased because VLC is only able to access the specific file that the user wants to open, rather than any file at any time the application is open.
|
||||
|
||||
Hard-coded access to some kernel interfaces like [`/sys`](https://en.wikipedia.org/wiki/Sysfs) and [`/proc`](https://en.wikipedia.org/wiki/Procfs#Linux) and weak [seccomp](https://en.wikipedia.org/wiki/Seccomp) filters unfortunately cannot be secured by the user with Flatpak.
|
||||
|
||||
@@ -216,19 +202,17 @@ If you're running a server you may have heard of Linux Containers, Docker, or Po
|
||||
|
||||
[Docker](https://en.wikipedia.org/wiki/Docker_(software)) is one of the most common container solutions. It does not run a proper sandbox, and this means that there is a large kernel [attack surface](https://en.wikipedia.org/wiki/Attack_surface). The [daemon](https://en.wikipedia.org/wiki/Daemon_(computing)) controls everything and [typically](https://docs.docker.com/engine/security/rootless/#known-limitations) runs as root. If it crashes for some reason, all the containers will crash too. The [gVisor](https://en.wikipedia.org/wiki/GVisor) runtime which implements an application level kernel can help limit the number of [syscalls](https://en.wikipedia.org/wiki/System_call) an application can make and can help isolate it from the host's [kernel](https://en.wikipedia.org/wiki/Kernel_(operating_system)).
|
||||
|
||||
Redhat develops [Podman](https://docs.podman.io/en/latest/) and secures it with SELinux to [isolate](https://www.redhat.com/sysadmin/apparmor-selinux-isolation) containers from each other. One of the notable differences between Docker and Podman is that Docker requires [root](https://en.wikipedia.org/wiki/Superuser) while Podman can run with [rootless containers](https://developers.redhat.com/blog/2020/09/25/rootless-containers-with-podman-the-basics) that are also [daemonless](https://developers.redhat.com/blog/2018/08/29/intro-to-podman), meaning if one crashes they don't all come down.
|
||||
Red Hat develops [Podman](https://docs.podman.io/en/latest/) and secures it with SELinux to [isolate](https://www.redhat.com/sysadmin/apparmor-selinux-isolation) containers from each other. One of the notable differences between Docker and Podman is that Docker requires [root](https://en.wikipedia.org/wiki/Superuser) while Podman can run with [rootless containers](https://developers.redhat.com/blog/2020/09/25/rootless-containers-with-podman-the-basics) that are also [daemonless](https://developers.redhat.com/blog/2018/08/29/intro-to-podman), meaning if one crashes they don't all come down.
|
||||
|
||||
Another option is [Kata containers](https://katacontainers.io/), where virtual machines masquerade as containers. Each Kata container has its own Linux kernel and is isolated from the host.
|
||||
|
||||
These container technologies can be useful even for enthusiastic home users who may want to run certain web app software on their local area network (LAN) such as [vaultwarden](https://github.com/dani-garcia/vaultwarden) or images provided by [linuxserver.io](https://www.linuxserver.io) to increase privacy by decreasing dependence on various web services.
|
||||
|
||||
## Additional hardening
|
||||
|
||||
### Firewalls
|
||||
|
||||
A [firewall](https://en.wikipedia.org/wiki/Firewall_(computing)) may be used to secure connections to your system. If you're on a public network, the necessity of this may be greater than if you're on a local trusted network that you control. We would generally recommend that you block incoming connections only, unless you're using an application firewall such as [OpenSnitch](https://github.com/evilsocket/opensnitch) or [Portmaster](https://safing.io/portmaster/).
|
||||
|
||||
Redhat distributions (such as Fedora) are typically configured through [firewalld](https://en.wikipedia.org/wiki/Firewalld). Redhat has plenty of [documentation](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/using-and-configuring-firewalld_configuring-and-managing-networking) regarding this topic. There is also the [uncomplicated firewall](https://en.wikipedia.org/wiki/Uncomplicated_Firewall) which can be used as an alternative.
|
||||
Red Hat distributions (such as Fedora) are typically configured through [firewalld](https://en.wikipedia.org/wiki/Firewalld). Red Hat has plenty of [documentation](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_networking/using-and-configuring-firewalld_configuring-and-managing-networking) regarding this topic. There is also the [Uncomplicated Firewall](https://en.wikipedia.org/wiki/Uncomplicated_Firewall) which can be used as an alternative.
|
||||
|
||||
Consider blocking all ports which are **not** [well known](https://en.wikipedia.org/wiki/Well-known_port#Well-known_ports) or "privileged ports". That is, ports from 1025 up to 65535. Block both [TCP](https://en.wikipedia.org/wiki/Transmission_Control_Protocol) and [UDP](https://en.wikipedia.org/wiki/User_Datagram_Protocol) after the operating system is installed.
|
||||
|
||||
@@ -241,7 +225,6 @@ If you are using Flatpak packages, you can revoke their network socket access us
|
||||
If you are using non-classic [Snap](https://en.wikipedia.org/wiki/Snap_(package_manager)) packages on a system with proper snap confinement support (with both AppArmor and [CGroupsv1](https://en.wikipedia.org/wiki/Cgroups) present), you can use the Snap Store to revoke network permission as well. This is also not bypassable.
|
||||
|
||||
### Kernel hardening
|
||||
|
||||
There are some additional kernel hardening options such as configuring [sysctl](https://en.wikipedia.org/wiki/Sysctl#Linux) keys and [kernel command-line parameters](https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html) which are described in the following pages. We don't recommend you change these options unless you learn about what they do.
|
||||
|
||||
* [2.2 Sysctl](https://madaidans-insecurities.github.io/guides/linux-hardening.html#sysctl)
|
||||
@@ -270,7 +253,7 @@ If you use [Toolbox](https://docs.fedoraproject.org/en-US/fedora-silverblue/tool
|
||||
### Linux Pluggable Authentication Modules (PAM)
|
||||
There is also further hardening to [PAM](https://en.wikipedia.org/wiki/Linux_PAM) to secure authentication to your system. [14. PAM](https://madaidans-insecurities.github.io/guides/linux-hardening.html#pam) has some tips on this.
|
||||
|
||||
On Redhat distributions you can use [`authselect`](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_authentication_and_authorization_in_rhel/configuring-user-authentication-using-authselect_configuring-authentication-and-authorization-in-rhel) to configure this e.g.:
|
||||
On Red Hat distributions you can use [`authselect`](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_authentication_and_authorization_in_rhel/configuring-user-authentication-using-authselect_configuring-authentication-and-authorization-in-rhel) to configure this e.g.:
|
||||
|
||||
```
|
||||
sudo authselect select <profile_id, default: sssd> with-faillock without-nullok with-pamaccess
|
||||
@@ -286,7 +269,7 @@ Another alternative option if you're using the [linux-hardened](/linux-desktop/#
|
||||
### Secure Boot
|
||||
[Secure Boot](https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface#Secure_Boot) can be used to secure the boot process by preventing the loading of [unsigned](https://en.wikipedia.org/wiki/Public-key_cryptography) [UEFI](https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface) drivers or [boot loaders](https://en.wikipedia.org/wiki/Bootloader). Some guidance for this is provided in [21. Physical security](https://madaidans-insecurities.github.io/guides/linux-hardening.html#physical-security) and [21.4 Verified boot](https://madaidans-insecurities.github.io/guides/linux-hardening.html#verified-boot).
|
||||
|
||||
For further resources on Secure Boot we suggest taking a look at the following for instructional advice
|
||||
For further resources on Secure Boot we suggest taking a look at the following for instructional advice:
|
||||
* The Archwiki's [Secure Boot](https://wiki.archlinux.org/title/Unified_Extensible_Firmware_Interface/Secure_Boot) article. There are two main methods, the first is to use a [shim](https://wiki.archlinux.org/title/Unified_Extensible_Firmware_Interface/Secure_Boot#shim), the second more complete way is to [use your own keys](https://wiki.archlinux.org/title/Unified_Extensible_Firmware_Interface/Secure_Boot#Using_your_own_keys).
|
||||
|
||||
For background of how Secure Boot works on Linux:
|
||||
@@ -301,6 +284,6 @@ One of the problems with Secure Boot particularly on Linux is that only the [cha
|
||||
* [Encrypting the boot partition](https://wiki.archlinux.org/title/GRUB#Encrypted_/boot). However, this has its own issues, the first being that [GRUB](https://en.wikipedia.org/wiki/GNU_GRUB) only supports [LUKS1](https://en.wikipedia.org/wiki/Linux_Unified_Key_Setup) and not the newer default LUKS2 scheme. As the bootloader runs in [protected mode](https://en.wikipedia.org/wiki/Protected_mode) and the encryption module lacks [SSE acceleration](https://en.wikipedia.org/wiki/Streaming_SIMD_Extensions) the boot process will take minutes to complete.
|
||||
* Using [TPM](https://en.wikipedia.org/wiki/Trusted_Platform_Module) to perform a [measured boot](https://www.krose.org/~krose/measured_boot).
|
||||
|
||||
After setting up Secure Boot it is crucial that you set a "firmware password" (also called a "supervisor password, "BIOS password" or "UEFI password"), otherwise an adversary can simply disable secure boot.
|
||||
After setting up Secure Boot it is crucial that you set a "firmware password" (also called a "supervisor password, "BIOS password" or "UEFI password"), otherwise an adversary can simply disable Secure Boot.
|
||||
|
||||
These recommendations can make you a little more resistant to [evil maid](https://en.wikipedia.org/wiki/Evil_maid_attack) attacks, but they not good as a proper verified boot process such as that found on [Android](https://source.android.com/security/verifiedboot), [ChromeOS](https://support.google.com/chromebook/answer/3438631) or [Windows](https://docs.microsoft.com/en-us/windows/security/information-protection/secure-the-windows-10-boot-process).
|
||||
|
||||
@@ -6,7 +6,6 @@ description: |
|
||||
---
|
||||
|
||||
## Encrypted Instant Messengers
|
||||
|
||||
{% for item_hash in site.data.software.messengers %}
|
||||
{% assign item = item_hash[1] %}
|
||||
|
||||
@@ -16,11 +15,9 @@ description: |
|
||||
{% endfor %}
|
||||
|
||||
## Types of Communication Networks
|
||||
|
||||
There are several network architectures commonly used to relay messages between users. These networks can provide different different privacy guarantees, which is why it's worth considering your [threat model](https://en.wikipedia.org/wiki/Threat_model) when making a decision about which app to use.
|
||||
|
||||
### Centralized Networks
|
||||
|
||||
{% capture markdown_text %}
|
||||
Centralized messengers are those where all participants are on the same server or network of servers controlled by the same organization.
|
||||
|
||||
@@ -55,7 +52,6 @@ Some self-hosted messengers allow you to set up your own server. Self-hosting ca
|
||||
</div>
|
||||
|
||||
### Federated Networks
|
||||
|
||||
{% capture markdown_text %}
|
||||
Federated messengers use multiple, independent, decentralized servers that are able to talk to each other (email is one example of a federated service). Federation allows system administrators to control their own server and still be a part of the larger communications network.
|
||||
|
||||
@@ -88,7 +84,6 @@ When self-hosted, users of a federated server can discover and communicate with
|
||||
</div>
|
||||
|
||||
### Peer-to-Peer (P2P) Networks
|
||||
|
||||
{% capture markdown_text %}
|
||||
[P2P](https://en.wikipedia.org/wiki/Peer-to-peer) messengers connect to a [distributed network](https://en.wikipedia.org/wiki/Distributed_networking) of nodes to relay a message to the recepient without a third-party server.
|
||||
|
||||
@@ -125,7 +120,6 @@ P2P networks do not use servers, as users communicate directly between each othe
|
||||
</div>
|
||||
|
||||
### Anonymous Routing
|
||||
|
||||
{% capture markdown_text %}
|
||||
A messenger using [anonymous routing](https://doi.org/10.1007/978-1-4419-5906-5_628) hides either the identity of the sender, the receiver, or evidence that they have been communicating. Ideally, a messenger should hide all three.
|
||||
|
||||
|
||||
@@ -14,4 +14,3 @@ description: |
|
||||
{% endif %}
|
||||
|
||||
{% endfor %}
|
||||
|
||||
|
||||
@@ -16,9 +16,9 @@ By focusing on the threats that matter to you, this narrows down your thinking a
|
||||
Examples of threat models
|
||||
-------------------------
|
||||
|
||||
* An investigative journalist's threat model might be <span class="text-muted">(protecting themselves against)</span> a foreign government.
|
||||
* A company's manager's threat model might be <span class="text-muted">(protecting themselves against)</span> a hacker hired by competition to do corporate espionage.
|
||||
* The average citizen's threat model might be <span class="text-muted">(hiding their data from)</span> large tech corporations.
|
||||
* An investigative journalist's threat model might be <span class="text-muted">(protecting themselves against)</span> a foreign government.
|
||||
* A company's manager's threat model might be <span class="text-muted">(protecting themselves against)</span> a hacker hired by competition to do corporate espionage.
|
||||
* The average citizen's threat model might be <span class="text-muted">(hiding their data from)</span> large tech corporations.
|
||||
|
||||
Creating your threat model
|
||||
--------------------------
|
||||
@@ -33,28 +33,22 @@ To identify what could happen to the things you value and determine from whom yo
|
||||
|
||||
{% capture markdown_text %}
|
||||
#### Example: Protecting your belongings
|
||||
|
||||
* To demonstrate how these questions work, let's build a plan to keep your house and possessions safe.
|
||||
* To demonstrate how these questions work, let's build a plan to keep your house and possessions safe.
|
||||
|
||||
##### What do you want to protect? (Or, _what do you have that is worth protecting?_)
|
||||
|
||||
* Your assets might include jewelry, electronics, important documents, or photos.
|
||||
* Your assets might include jewelry, electronics, important documents, or photos.
|
||||
|
||||
##### Who do you want to protect it from?
|
||||
|
||||
* Your adversaries might include burglars, roommates, or guests.
|
||||
* Your adversaries might include burglars, roommates, or guests.
|
||||
|
||||
##### How likely is it that you will need to protect it?
|
||||
|
||||
* Does your neighborhood have a history of burglaries? How trustworthy are your roommates/guests? What are the capabilities of your adversaries? What are the risks you should consider?
|
||||
* Does your neighborhood have a history of burglaries? How trustworthy are your roommates/guests? What are the capabilities of your adversaries? What are the risks you should consider?
|
||||
|
||||
##### How bad are the consequences if you fail?
|
||||
|
||||
* Do you have anything in your house that you cannot replace? Do you have the time or money to replace these things? Do you have insurance that covers goods stolen from your home?
|
||||
* Do you have anything in your house that you cannot replace? Do you have the time or money to replace these things? Do you have insurance that covers goods stolen from your home?
|
||||
|
||||
##### How much trouble are you willing to go through to prevent these consequences?
|
||||
|
||||
* Are you willing to buy a safe for sensitive documents? Can you afford to buy a high-quality lock? Do you have time to open a security box at your local bank and keep your valuables there?
|
||||
* Are you willing to buy a safe for sensitive documents? Can you afford to buy a high-quality lock? Do you have time to open a security box at your local bank and keep your valuables there?
|
||||
|
||||
Only once you have asked yourself these questions will you be in a position to assess what measures to take. If your possessions are valuable, but the probability of a break-in is low, then you may not want to invest too much money in a lock. But, if the probability of a break-in is high, you'll want to get the best lock on the market, and consider adding a security system.
|
||||
|
||||
@@ -65,13 +59,11 @@ Making a security plan will help you to understand the threats that are unique t
|
||||
Now, let's take a closer look at the questions in our list:
|
||||
|
||||
### What do I want to protect?
|
||||
|
||||
An “asset” is something you value and want to protect. In the context of digital security, <mark>an asset is usually some kind of information.</mark> For example, your emails, contact lists, instant messages, location, and files are all possible assets. Your devices themselves may also be assets.
|
||||
|
||||
_Make a list of your assets: data that you keep, where it's kept, who has access to it, and what stops others from accessing it._
|
||||
|
||||
### Who do I want to protect it from?
|
||||
|
||||
To answer this question, it's important to identify who might want to target you or your information. <mark>A person or entity that poses a threat to your assets is an “adversary.”</mark> Examples of potential adversaries are your boss, your former partner, your business competition, your government, or a hacker on a public network.
|
||||
|
||||
_Make a list of your adversaries, or those who might want to get ahold of your assets. Your list may include individuals, a government agency, or corporations._
|
||||
@@ -79,7 +71,6 @@ _Make a list of your adversaries, or those who might want to get ahold of your a
|
||||
Depending on who your adversaries are, under some circumstances this list might be something you want to destroy after you're done security planning.
|
||||
|
||||
### How likely is it that I will need to protect it?
|
||||
|
||||
<mark>Risk is the likelihood that a particular threat against a particular asset will actually occur.</mark> It goes hand-in-hand with capability. While your mobile phone provider has the capability to access all of your data, the risk of them posting your private data online to harm your reputation is low.
|
||||
|
||||
It is important to distinguish between what might happen and the probability it may happen. For instance, there is a threat that your building might collapse, but the risk of this happening is far greater in San Francisco (where earthquakes are common) than in Stockholm (where they are not).
|
||||
@@ -89,7 +80,6 @@ Assessing risks is both a personal and a subjective process. Many people find ce
|
||||
_Write down which threats you are going to take seriously, and which may be too rare or too harmless (or too difficult to combat) to worry about._
|
||||
|
||||
### How bad are the consequences if I fail?
|
||||
|
||||
There are many ways that an adversary could gain access to your data. For example, an adversary can read your private communications as they pass through the network, or they can delete or corrupt your data.
|
||||
|
||||
<mark>The motives of adversaries differ widely, as do their tactics.</mark> A government trying to prevent the spread of a video showing police violence may be content to simply delete or reduce the availability of that video. In contrast, a political opponent may wish to gain access to secret content and publish that content without you knowing.
|
||||
@@ -99,7 +89,6 @@ Security planning involves understanding how bad the consequences could be if an
|
||||
_Write down what your adversary might want to do with your private data._
|
||||
|
||||
### How much trouble am I willing to go through to try to prevent potential consequences?
|
||||
|
||||
<mark>There is no perfect option for security.</mark> Not everyone has the same priorities, concerns, or access to resources. Your risk assessment will allow you to plan the right strategy for you, balancing convenience, cost, and privacy.
|
||||
|
||||
For example, an attorney representing a client in a national security case may be willing to go to greater lengths to protect communications about that case, such as using encrypted email, than a mother who regularly emails her daughter funny cat videos.
|
||||
|
||||
Reference in New Issue
Block a user