| page.title=Security Enhancements in Android 5.0 |
| @jd:body |
| |
| <p>Every Android release includes dozens of security enhancements to protect |
| users. Here are some of the major security enhancements available in Android |
| 5.0:</p> |
| |
| <ul> |
| <li><strong>Encrypted by default.</strong> On devices that ship with L |
| out-of-the-box, full disk encryption is enabled by default to improve |
| protection of data on lost or stolen devices. Devices that |
| update to L can be encrypted in <strong>Settings</strong> > <strong>Security</strong>. |
| <li><strong>Improved full disk encryption.</strong> The user password is |
| protected against brute-force attacks using <code>scrypt</code> and, where |
| available, the key is bound to the hardware keystore to prevent |
| off-device attacks. As always, the Android screen lock secret and the device |
| encryption key are not sent off the device or exposed to any application. |
| <li><strong>Android sandbox reinforced with SELinux</strong>. Android now |
| requires SELinux in enforcing mode for all domains. SELinux is a |
| mandatory access control (MAC) system in the Linux kernel used to augment the |
| existing discretionary access control (DAC) security model. This new layer |
| provides additional protection against potential security vulnerabilities. |
| <li><strong>Smart Lock. </strong>Android now includes trustlets that provide |
| more flexibility for unlocking devices. For example, trustlets can allow |
| devices to be unlocked automatically when close to another trusted device (via |
| NFC, Bluetooth) or being used by someone with a trusted face. |
| <li><strong>Multi user, restricted profile, and guest modes for phones & |
| tablets.</strong> Android now provides for multiple users on phones and |
| includes a guest mode that can be used to provide easy temporary access to your |
| device without granting access to your data and apps. |
| <li><strong>Updates to WebView without OTA. </strong> WebView can now be |
| updated independent of the framework and without a system |
| OTA. This will allow for faster response to potential security issues in |
| WebView. |
| <li><strong>Updated cryptography for HTTPS and TLS/SSL.</strong> TLSv1.2 and |
| TLSv1.1 is now enabled, Forward Secrecy is now preferred, AES-GCM |
| is now enabled, and weak cipher suites (MD5, 3DES, and export cipher suites) |
| are now disabled. See <a |
| href="https://developer.android.com/reference/javax/net/ssl/SSLSocket.html">https://developer.android.com/reference/javax/net/ssl/SSLSocket.html</a> |
| for more details. |
| <li><strong>non-PIE linker support removed.</strong> Android now requires all |
| dynamically linked executables to support PIE |
| (position-independent executables). This enhances Android’s address space |
| layout randomization (ASLR) implementation. |
| <li><strong>FORTIFY_SOURCE improvements.</strong> The following libc |
| functions now implement FORTIFY_SOURCE protections: <code>stpcpy()</code>, |
| <code>stpncpy()</code>, <code>read()</code>, <code>recvfrom()</code>, |
| <code>FD_CLR()</code>, <code>FD_SET()</code>, and <code>FD_ISSET()</code>. This |
| provides protection against memory-corruption vulnerabilities involving |
| those functions. |
| <li><strong>Security Fixes.</strong> Android 5.0 also includes fixes for |
| Android-specific vulnerabilities. Information about these vulnerabilities has |
| been provided to Open Handset Alliance members, and fixes are available in |
| Android Open Source Project. To improve security, some devices with earlier |
| versions of Android may also include these fixes. |
| </ul> |
