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  1. <?xml version="1.0" encoding="UTF-8" ?>
  2. <html>
  3. <head>
  4. <title>"Secure Boot": Who will control your next computer?</title>
  5. </head>
  6. <body id="secure-boot-analysis" class="article" microformats="h-entry">
  7. <!--<p id="category">
  8. <a href="/freesoftware/freesoftware.html">Free Software</a>
  9. </p>-->
  10. <h1 class="p-name">"Secure Boot": Who will control your next computer?</h1>
  11. <div class="e-content">
  12. <p class="p-summary">FSFE's goal is to ensure that the owners of IT devices are always in full
  13. and sole control of them. <!-- German: permanent die volle und alleinige
  14. Verfügungsgewalt über ihre IT-Geräte innehaben) --> This fundamental principle
  15. is recently being challenged.</p>
  16. <p>With a function called "Secure Boot", which will be deployed in computers
  17. starting 2012, manufacturers of IT hardware and software components are
  18. striving to get into a position where they permanently control the IT devices
  19. they produce. Hence such devices will be "secure" from the manufacturer's
  20. perspective, but not necessarily from the owner's point of view. As a result, the owner could
  21. be treated as an adversary. By preventing uses of the device which the
  22. manufacturer does not intend, they can control and limit what a general purpose
  23. IT machine (e.g. a PC, laptop, netbook) may be used for. In case of IT devices
  24. with internet access, they can alter these usage restrictions at any time
  25. without even informing the device owner. As a result, IT manufacturers can take away common rights owners of products usually receive at will.</p>
  26. <h2>"Secure Boot": Gatekeeper before the operating system</h2>
  27. <p>When powered on, IT devices execute a startup process called booting. In
  28. case of computers this startup process is comprised of executing firmware. This
  29. firmware, in turn, starts another program called a boot loader, which then
  30. launches the actual operating system, on top of which applications can be
  31. executed. In 2012 the industry-wide transition of PCs, notebooks, servers, and
  32. other computers' firmware from conventional BIOS to <a
  33. href="http://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface">UEFI</a> will be mostly
  34. complete. Compared to conventional BIOS, UEFI has several advantages, such as
  35. faster boot time, operating system independent drivers, and the promise of
  36. extended security.</p>
  37. <p>The security aspect is handled by a function called "Secure Boot". Since
  38. UEFI 2.3.1 (released April 8, 2011) "Secure Boot" ensures that during the boot
  39. process only software will execute, which complies with one of predeployed
  40. cryptographic signatures. This is done to prevent unwanted software from being
  41. executed during the startup of the computer, by cryptographically verifying a
  42. signature of each software component (various stages of the UEFI firmware, the
  43. boot loader, the operating system kernel, etc.) before starting it. Therefore
  44. the cryptographic signatures to be utilised have to be deployed in the UEFI
  45. signature database of each IT device equipped with UEFI "Secure Boot",
  46. <strong>before</strong> a cryptographically signed software component can be
  47. started on that specific machine.</p>
  48. <p>FSFE expects that the vast majority of the computer manufacturers will
  49. implement "Secure Boot", as Microsoft <a
  50. href="http://msdn.microsoft.com/en-us/library/windows/hardware/hh748200.aspx">has
  51. announced</a> that computer manufacturers must implement UEFI "Secure Boot",
  52. if they want to acquire a Windows 8 certification for devices they build, e.g.
  53. for putting the "Compatible with Windows 8" logo on them. </p>
  54. <aside>
  55. <h2>The computer: a general purpose machine</h2>
  56. <p>Evolving the computer as a general purpose machine over the past decades,
  57. our society has created a powerful tool to perform all kinds of tasks with a
  58. single machine. Now IT manufacturers have discovered that they may have an
  59. economic interest to arbitrarily limit what these machines can achieve. With
  60. "Secure Boot" the owners of IT devices will not be able to independently
  61. determine the usage of their machines, as they cannot decide which software to
  62. run.</p>
  63. <p>The entity who eventually controls which software can be executed on a
  64. device and thus determines the specific functions the device performs,
  65. ultimately can control any data processed and stored by the device. In result,
  66. the owner of an IT device may not be in sole control of their own data any
  67. more.</p>
  68. </aside>
  69. <h2>For which devices does this apply?</h2>
  70. <p>Currently many people base their analysis of the UEFI situation on the
  71. "Windows 8 Hardware Certification Requirements", published by Microsoft in
  72. December 2011. It is understood that Microsoft did not and still does not have
  73. to make any versions of these hardware-certification requirements public, as
  74. they are the base of an individual contract between Microsoft and each hardware
  75. manufacturer seeking to obtain Microsoft's Windows 8 Certification for their
  76. computer-products. Hence the "Windows 8 Hardware Certification Requirements"
  77. can change anytime without public notice, or specific details of the
  78. logo-requirements may differ between manufacturers: Everything happens at
  79. Microsoft's will and mostly behind closed doors. Thus nobody can rely on the
  80. published version of the "Windows 8 Hardware Certification Requirements" being
  81. static, but realise the details devised for "Secure Boot" as a "moving
  82. target".</p>
  83. <p>So the problem of "Secure Boot" is not necessarily limited to "Connected
  84. Stand-By Systems" (probably a large share of the future market of notebooks,
  85. netbooks and PCs) and computers based on ARM microprocessors (mainly tablets
  86. and mobile phones), but can be expanded to any other type of devices by
  87. Microsoft anytime. Equally, hardware manufacturers not producing Windows 8
  88. devices may deploy UEFI "Secure Boot" or other boot processes restricted by the
  89. help of cryptographic signatures. TiVo has been doing this for a decade, and
  90. various gaming consoles from Sony to Microsoft are using cryptographically
  91. restricted boot processes as well. Other device manufacturers may employ
  92. specifications or requirements similar to the "Windows 8 Hardware Certification
  93. Requirements", in order to artificially restrict the capabilities of IT
  94. devices.</p>
  95. <h2>Restrictions to be extended to applications?</h2>
  96. <p>While the UEFI "Secure Boot" specification (as well as the specifications of
  97. the Trusted Computing Group defining "Trusted Boot") covers the primary boot
  98. process up to the operating system's kernel, the infrastructure to extend
  99. signature-checking to all software running on a computer is mature and working
  100. in various operating systems. But beside Windows 8 it is currently only
  101. enforced for Windows device drivers.</p>
  102. <h2>Threat to general purpose computing</h2>
  103. <p>If all these measures would be solely under control of device owners, these
  104. could be in their best interest, helping them to enhance security of the boot
  105. process, which today is mostly unsecured. This would be the case
  106. <strong>if</strong> the security subsystems specified by the UEFI forum and the
  107. Trusted Computing Group (TCG) would <strong>technically</strong> <!-- they can
  108. guarantee a lot, but they have to do it technically --> guarantee the owner's
  109. permanent, full and sole control over configuration and management of these
  110. security subsystems, which includes the creation, storage, use and deletion of
  111. cryptographic keys, certificates and signatures. But as soon as other entities
  112. beside the device owner can utilise these security subsystems, this enables
  113. them to preclude unintended or simply unforeseen usages of these IT
  114. devices.</p>
  115. <p>Hence, with the implementation of "Secure Boot", the availability of true
  116. general purpose computers under full owner control may be greatly reduced.
  117. Devices significantly restricted by measures as "Secure Boot" under company
  118. control are usually called appliances or special purpose computers (e.g. media
  119. centres, telephones, book readers). Thus at least some Windows 8 devices will
  120. rather constitute a Windows appliance than a customary computer. While there
  121. may be a market for such computing appliances, the FSFE strongly calls for
  122. clearly labelling such IT devices as restricted to use models foreseen by a
  123. company, in order to duly inform a potential buyer.</p>
  124. <h2>Is circumventing these restrictions an option?</h2>
  125. <p>IT savvy people may think that they have seen such measures before, and most
  126. of them were cracked. This was the case in various models of the PlayStation
  127. and Xbox gaming consoles, as well as many newer mobile phones. But the quality
  128. and breadth is wider this time:</p>
  129. <ul>
  130. <li>UEFI "Secure Boot" is primarily aimed at traditional PCs.</li>
  131. <li>It is backed by large parts of the IT industry, see e.g. <a
  132. href="http://www.uefi.org/about/">the members of the UEFI Forum.</a></li>
  133. <li>Its design and specification are the result of a collective effort of IT
  134. engineers from various companies. It draws on a decade of experience with
  135. signature based boot processes and hence avoids many classical pitfalls, e.g.
  136. the lack of a properly specified and cryptographically secured firmware
  137. (UEFI) update process.</li>
  138. <li>It utilises hardware based security subsystems, e.g. as specified by the
  139. TCG (TPM or MTM, and accompanying specifications): While the UEFI
  140. specification does not mandate a specific implementation of "protected
  141. storage" for cryptographic keys, certificates and signatures, the recent TCG
  142. specifications (since 2011) fit well.</li>
  143. <li>Security flaws in "Secure Boot" implementations are expected (as in all
  144. software), but as there will be commercial competition between UEFI vendors,
  145. it is in their best interest to resolve these security flaws. In contrast, in
  146. the past only individual manufacturers implemented cryptographically
  147. restricted boot processes for their own, specific devices: TiVo Inc. for
  148. their TIVOs, Microsoft for various generations of their Xbox, as well as Sony
  149. for their Playstations. </li>
  150. </ul>
  151. <p>Furthermore, even though many of similar usage restrictions have been cracked
  152. in the past, this only shows that their technical implementations were flawed
  153. and open to malware, hence not providing the "security" they were designed for.
  154. Although this is likely to apply to some "Secure Boot" implementations as well,
  155. breaking such mechanisms can never be a solution for freedom issues or the lack
  156. of controllability by the device owner.</p>
  157. <h2>FSFE's demands</h2>
  158. <p>For maintaining sustained growth in the development and use of software, the
  159. broad availability of general purpose computers is crucial.</p>
  160. <p>FSFE demands that before purchasing a device, buyers must be informed
  161. concisely about the technical measures implemented in this device, as well as
  162. the specific usage restrictions and their consequences for the owner.</p>
  163. <p>Furthermore, FSFE strongly recommends to exclusively purchase IT devices
  164. which grant their owners full, sole and permanent control over security
  165. subsystems (e. g. signature-based usage restrictions), in order to maintain the
  166. ability to install arbitrary software and lastly to retain exclusive control
  167. over one's own data.</p>
  168. </div>
  169. <!--/e-content-->
  170. </body>
  171. <sidebar promo="our-work" />
  172. <timestamp>$Date$ $Author: Matthias Kirschner$</timestamp>
  173. <author id="kirschner" />
  174. <date>
  175. <original content="2012-06-01" />
  176. </date>
  177. </html>