Merge remote-tracking branch 'aosp/upstream_master' into init
am: 5bcd0f9063
Change-Id: I542eda1bf72d9bca0f3737c929c9a3433939d027
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..95457ca
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+fsverity
+*.o
+tags
+cscope.*
+ncscope.*
diff --git a/COPYING b/COPYING
new file mode 100644
index 0000000..d159169
--- /dev/null
+++ b/COPYING
@@ -0,0 +1,339 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The licenses for most software are designed to take away your
+freedom to share and change it. By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users. This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it. (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.) You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+ To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have. You must make sure that they, too, receive or can get the
+source code. And you must show them these terms so they know their
+rights.
+
+ We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+ Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software. If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+ Finally, any free program is threatened constantly by software
+patents. We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary. To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+ The precise terms and conditions for copying, distribution and
+modification follow.
+
+ GNU GENERAL PUBLIC LICENSE
+ TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+ 0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License. The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language. (Hereinafter, translation is included without limitation in
+the term "modification".) Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope. The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+ 1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+ 2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+ a) You must cause the modified files to carry prominent notices
+ stating that you changed the files and the date of any change.
+
+ b) You must cause any work that you distribute or publish, that in
+ whole or in part contains or is derived from the Program or any
+ part thereof, to be licensed as a whole at no charge to all third
+ parties under the terms of this License.
+
+ c) If the modified program normally reads commands interactively
+ when run, you must cause it, when started running for such
+ interactive use in the most ordinary way, to print or display an
+ announcement including an appropriate copyright notice and a
+ notice that there is no warranty (or else, saying that you provide
+ a warranty) and that users may redistribute the program under
+ these conditions, and telling the user how to view a copy of this
+ License. (Exception: if the Program itself is interactive but
+ does not normally print such an announcement, your work based on
+ the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole. If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works. But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+ 3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+ a) Accompany it with the complete corresponding machine-readable
+ source code, which must be distributed under the terms of Sections
+ 1 and 2 above on a medium customarily used for software interchange; or,
+
+ b) Accompany it with a written offer, valid for at least three
+ years, to give any third party, for a charge no more than your
+ cost of physically performing source distribution, a complete
+ machine-readable copy of the corresponding source code, to be
+ distributed under the terms of Sections 1 and 2 above on a medium
+ customarily used for software interchange; or,
+
+ c) Accompany it with the information you received as to the offer
+ to distribute corresponding source code. (This alternative is
+ allowed only for noncommercial distribution and only if you
+ received the program in object code or executable form with such
+ an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it. For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable. However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+ 4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License. Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+ 5. You are not required to accept this License, since you have not
+signed it. However, nothing else grants you permission to modify or
+distribute the Program or its derivative works. These actions are
+prohibited by law if you do not accept this License. Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+ 6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions. You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+ 7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License. If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all. For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices. Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+ 8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded. In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+ 9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time. Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number. If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation. If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+ 10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission. For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this. Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+ NO WARRANTY
+
+ 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+ 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+ Gnomovision version 69, Copyright (C) year name of author
+ Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary. Here is a sample; alter the names:
+
+ Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+ `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+ <signature of Ty Coon>, 1 April 1989
+ Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs. If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..d159169
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,339 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The licenses for most software are designed to take away your
+freedom to share and change it. By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users. This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it. (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.) You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+ To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have. You must make sure that they, too, receive or can get the
+source code. And you must show them these terms so they know their
+rights.
+
+ We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+ Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software. If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+ Finally, any free program is threatened constantly by software
+patents. We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary. To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+ The precise terms and conditions for copying, distribution and
+modification follow.
+
+ GNU GENERAL PUBLIC LICENSE
+ TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+ 0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License. The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language. (Hereinafter, translation is included without limitation in
+the term "modification".) Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope. The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+ 1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+ 2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+ a) You must cause the modified files to carry prominent notices
+ stating that you changed the files and the date of any change.
+
+ b) You must cause any work that you distribute or publish, that in
+ whole or in part contains or is derived from the Program or any
+ part thereof, to be licensed as a whole at no charge to all third
+ parties under the terms of this License.
+
+ c) If the modified program normally reads commands interactively
+ when run, you must cause it, when started running for such
+ interactive use in the most ordinary way, to print or display an
+ announcement including an appropriate copyright notice and a
+ notice that there is no warranty (or else, saying that you provide
+ a warranty) and that users may redistribute the program under
+ these conditions, and telling the user how to view a copy of this
+ License. (Exception: if the Program itself is interactive but
+ does not normally print such an announcement, your work based on
+ the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole. If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works. But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+ 3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+ a) Accompany it with the complete corresponding machine-readable
+ source code, which must be distributed under the terms of Sections
+ 1 and 2 above on a medium customarily used for software interchange; or,
+
+ b) Accompany it with a written offer, valid for at least three
+ years, to give any third party, for a charge no more than your
+ cost of physically performing source distribution, a complete
+ machine-readable copy of the corresponding source code, to be
+ distributed under the terms of Sections 1 and 2 above on a medium
+ customarily used for software interchange; or,
+
+ c) Accompany it with the information you received as to the offer
+ to distribute corresponding source code. (This alternative is
+ allowed only for noncommercial distribution and only if you
+ received the program in object code or executable form with such
+ an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it. For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable. However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+ 4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License. Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+ 5. You are not required to accept this License, since you have not
+signed it. However, nothing else grants you permission to modify or
+distribute the Program or its derivative works. These actions are
+prohibited by law if you do not accept this License. Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+ 6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions. You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+ 7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License. If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all. For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices. Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+ 8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded. In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+ 9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time. Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number. If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation. If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+ 10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission. For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this. Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+ NO WARRANTY
+
+ 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+ 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+ Gnomovision version 69, Copyright (C) year name of author
+ Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary. Here is a sample; alter the names:
+
+ Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+ `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+ <signature of Ty Coon>, 1 April 1989
+ Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs. If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.
diff --git a/METADATA b/METADATA
new file mode 100644
index 0000000..a9d6066
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,19 @@
+name: "fsverity-utils"
+description:
+ "This is `fsverity`, a userspace utility for fs-verity. fs-verity is "
+ "a Linux kernel feature that does transparent on-demand "
+ "integrity/authenticity verification of the contents of read-only "
+ "files, using a Merkle tree (hash tree) hidden after the end of the "
+ "file. The mechanism is similar to dm-verity, but implemented at the "
+ "file level rather than at the block device level. The `fsverity` "
+ "utility allows you to set up fs-verity protected files."
+
+third_party {
+ url {
+ type: GIT
+ value: "https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/fsverity-utils.git"
+ }
+ version: "bdebc45b4527d64109723ad5753fa514bac47c9f"
+ last_upgrade_date { year: 2018 month: 10 day: 4 }
+ license_type: RESTRICTED
+}
diff --git a/MODULE_LICENSE_GPL b/MODULE_LICENSE_GPL
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/MODULE_LICENSE_GPL
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..b9c09b9
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,22 @@
+EXE := fsverity
+CFLAGS := -O2 -Wall
+CPPFLAGS := -D_FILE_OFFSET_BITS=64
+LDLIBS := -lcrypto
+DESTDIR := /usr/local
+SRC := $(wildcard *.c)
+OBJ := $(SRC:.c=.o)
+HDRS := $(wildcard *.h)
+
+all:$(EXE)
+
+$(EXE):$(OBJ)
+
+$(OBJ): %.o: %.c $(HDRS)
+
+clean:
+ rm -f $(EXE) $(OBJ)
+
+install:all
+ install -Dm755 -t $(DESTDIR)/bin $(EXE)
+
+.PHONY: all clean install
diff --git a/NOTICE b/NOTICE
new file mode 100644
index 0000000..d159169
--- /dev/null
+++ b/NOTICE
@@ -0,0 +1,339 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The licenses for most software are designed to take away your
+freedom to share and change it. By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users. This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it. (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.) You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+ To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have. You must make sure that they, too, receive or can get the
+source code. And you must show them these terms so they know their
+rights.
+
+ We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+ Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software. If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+ Finally, any free program is threatened constantly by software
+patents. We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary. To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+ The precise terms and conditions for copying, distribution and
+modification follow.
+
+ GNU GENERAL PUBLIC LICENSE
+ TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+ 0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License. The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language. (Hereinafter, translation is included without limitation in
+the term "modification".) Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope. The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+ 1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+ 2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+ a) You must cause the modified files to carry prominent notices
+ stating that you changed the files and the date of any change.
+
+ b) You must cause any work that you distribute or publish, that in
+ whole or in part contains or is derived from the Program or any
+ part thereof, to be licensed as a whole at no charge to all third
+ parties under the terms of this License.
+
+ c) If the modified program normally reads commands interactively
+ when run, you must cause it, when started running for such
+ interactive use in the most ordinary way, to print or display an
+ announcement including an appropriate copyright notice and a
+ notice that there is no warranty (or else, saying that you provide
+ a warranty) and that users may redistribute the program under
+ these conditions, and telling the user how to view a copy of this
+ License. (Exception: if the Program itself is interactive but
+ does not normally print such an announcement, your work based on
+ the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole. If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works. But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+ 3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+ a) Accompany it with the complete corresponding machine-readable
+ source code, which must be distributed under the terms of Sections
+ 1 and 2 above on a medium customarily used for software interchange; or,
+
+ b) Accompany it with a written offer, valid for at least three
+ years, to give any third party, for a charge no more than your
+ cost of physically performing source distribution, a complete
+ machine-readable copy of the corresponding source code, to be
+ distributed under the terms of Sections 1 and 2 above on a medium
+ customarily used for software interchange; or,
+
+ c) Accompany it with the information you received as to the offer
+ to distribute corresponding source code. (This alternative is
+ allowed only for noncommercial distribution and only if you
+ received the program in object code or executable form with such
+ an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it. For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable. However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+ 4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License. Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+ 5. You are not required to accept this License, since you have not
+signed it. However, nothing else grants you permission to modify or
+distribute the Program or its derivative works. These actions are
+prohibited by law if you do not accept this License. Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+ 6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions. You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+ 7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License. If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all. For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices. Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+ 8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded. In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+ 9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time. Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number. If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation. If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+ 10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission. For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this. Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+ NO WARRANTY
+
+ 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+ 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+ Gnomovision version 69, Copyright (C) year name of author
+ Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary. Here is a sample; alter the names:
+
+ Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+ `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+ <signature of Ty Coon>, 1 April 1989
+ Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs. If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..be2a251
--- /dev/null
+++ b/README.md
@@ -0,0 +1,162 @@
+# Introduction
+
+This is `fsverity`, a userspace utility for fs-verity. fs-verity is
+a Linux kernel feature that does transparent on-demand
+integrity/authenticity verification of the contents of read-only
+files, using a Merkle tree (hash tree) hidden after the end of the
+file. The mechanism is similar to dm-verity, but implemented at the
+file level rather than at the block device level. The `fsverity`
+utility allows you to set up fs-verity protected files.
+
+fs-verity will initially be supported by the ext4 and f2fs
+filesystems, but it may later be supported by other filesystems too.
+
+# Building and installing
+
+The `fsverity` utility uses the OpenSSL library, so you first must
+install the needed development files. For example, on Debian-based
+systems, run:
+
+```bash
+ sudo apt-get install libssl-dev
+```
+
+OpenSSL must be version 1.0.0 or later.
+
+Then, to build and install:
+
+```bash
+ make
+ sudo make install
+```
+
+# Examples
+
+## Basic use
+
+```bash
+ mkfs.f2fs -O verity /dev/vdc
+ mount /dev/vdc /vdc
+ cd /vdc
+
+ # Create a test file
+ head -c 1000000 /dev/urandom > file
+ md5sum file
+
+ # Append the Merkle tree and other metadata to the file:
+ fsverity setup file
+
+ # Enable fs-verity on the file
+ fsverity enable file
+
+ # Should show the same hash that 'fsverity setup' printed.
+ # This hash can be logged, or compared to a trusted value.
+ fsverity measure file
+
+ # Contents are now transparently verified and should match the
+ # original file contents, i.e. the metadata is hidden.
+ md5sum file
+```
+
+Note that in the above example, the file isn't signed. Therefore, to
+get any authenticity protection (as opposed to just integrity
+protection), the output of `fsverity measure` needs to be compared
+against a trusted value.
+
+## Using builtin signatures
+
+With `CONFIG_FS_VERITY_BUILTIN_SIGNATURES=y`, the filesystem supports
+automatically verifying a signed file measurement that has been
+included in the fs-verity metadata. The signature is verified against
+the set of X.509 certificates that have been loaded into the
+".fs-verity" kernel keyring. Here's an example:
+
+```bash
+ # Generate a new certificate and private key:
+ openssl req -newkey rsa:4096 -nodes -keyout key.pem -x509 -out cert.pem
+
+ # Convert the certificate from PEM to DER format:
+ openssl x509 -in cert.pem -out cert.der -outform der
+
+ # Load the certificate into the fs-verity keyring:
+ keyctl padd asymmetric '' %keyring:.fs-verity < cert.der
+
+ # Optionally, lock the keyring so that no more keys can be added
+ # (requires keyctl v1.5.11 or later):
+ keyctl restrict_keyring %keyring:.fs-verity
+
+ # Optionally, require that all fs-verity files be signed:
+ sysctl fs.verity.require_signatures=1
+
+ # Now set up fs-verity on a test file:
+ md5sum file
+ fsverity setup file --signing-key=key.pem --signing-cert=cert.pem
+ fsverity enable file
+ md5sum file
+```
+
+By default, it's not required that fs-verity files have a signature.
+This can be changed with `sysctl fs.verity.require_signatures=1`.
+When set, it's guaranteed that the contents of every fs-verity file
+has been signed by one of the certificates in the keyring.
+
+Note: applications generally still need to check whether the file
+they're accessing really is a fs-verity file, since an attacker could
+replace a fs-verity file with a regular one.
+
+## With IMA
+
+IMA support for fs-verity is planned.
+
+# Notices
+
+This project is provided under the terms of the GNU General Public
+License, version 2; or at your option, any later version. A copy of the
+GPLv2 can be found in the file named [COPYING](COPYING).
+
+Permission to link to OpenSSL (libcrypto) is granted.
+
+Send questions and bug reports to linux-fscrypt@vger.kernel.org.
+
+# Submitting patches
+
+Send patches to linux-fscrypt@vger.kernel.org. Patches should follow
+the Linux kernel's coding style. Additionally, like the Linux kernel
+itself, patches require the following "sign-off" procedure:
+
+The sign-off is a simple line at the end of the explanation for the
+patch, which certifies that you wrote it or otherwise have the right
+to pass it on as an open-source patch. The rules are pretty simple:
+if you can certify the below:
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+ (a) The contribution was created in whole or in part by me and I
+ have the right to submit it under the open source license
+ indicated in the file; or
+
+ (b) The contribution is based upon previous work that, to the best
+ of my knowledge, is covered under an appropriate open source
+ license and I have the right under that license to submit that
+ work with modifications, whether created in whole or in part
+ by me, under the same open source license (unless I am
+ permitted to submit under a different license), as indicated
+ in the file; or
+
+ (c) The contribution was provided directly to me by some other
+ person who certified (a), (b) or (c) and I have not modified
+ it.
+
+ (d) I understand and agree that this project and the contribution
+ are public and that a record of the contribution (including all
+ personal information I submit with it, including my sign-off) is
+ maintained indefinitely and may be redistributed consistent with
+ this project or the open source license(s) involved.
+
+then you just add a line saying::
+
+ Signed-off-by: Random J Developer <random@developer.example.org>
+
+using your real name (sorry, no pseudonyms or anonymous contributions.)
diff --git a/cmd_enable.c b/cmd_enable.c
new file mode 100644
index 0000000..ed092f0
--- /dev/null
+++ b/cmd_enable.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The 'fsverity enable' command
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+#include "commands.h"
+#include "fsverity_uapi.h"
+
+int fsverity_cmd_enable(const struct fsverity_command *cmd,
+ int argc, char *argv[])
+{
+ struct filedes file;
+
+ if (argc != 2) {
+ usage(cmd, stderr);
+ return 2;
+ }
+
+ if (!open_file(&file, argv[1], O_RDONLY, 0))
+ return 1;
+ if (ioctl(file.fd, FS_IOC_ENABLE_VERITY, NULL) != 0) {
+ error_msg_errno("FS_IOC_ENABLE_VERITY failed on '%s'",
+ file.name);
+ filedes_close(&file);
+ return 1;
+ }
+ if (!filedes_close(&file))
+ return 1;
+ return 0;
+}
diff --git a/cmd_measure.c b/cmd_measure.c
new file mode 100644
index 0000000..a5480a6
--- /dev/null
+++ b/cmd_measure.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The 'fsverity measure' command
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+
+#include "commands.h"
+#include "fsverity_uapi.h"
+#include "hash_algs.h"
+
+int fsverity_cmd_measure(const struct fsverity_command *cmd,
+ int argc, char *argv[])
+{
+ struct fsverity_digest *d = NULL;
+ struct filedes file;
+ char digest_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + 1];
+ const struct fsverity_hash_alg *hash_alg;
+ char _hash_alg_name[32];
+ const char *hash_alg_name;
+ int status;
+ int i;
+
+ if (argc < 2)
+ goto out_usage;
+
+ d = xzalloc(sizeof(*d) + FS_VERITY_MAX_DIGEST_SIZE);
+
+ for (i = 1; i < argc; i++) {
+ d->digest_size = FS_VERITY_MAX_DIGEST_SIZE;
+
+ if (!open_file(&file, argv[i], O_RDONLY, 0))
+ goto out_err;
+ if (ioctl(file.fd, FS_IOC_MEASURE_VERITY, d) != 0) {
+ error_msg_errno("FS_IOC_MEASURE_VERITY failed on '%s'",
+ file.name);
+ filedes_close(&file);
+ goto out_err;
+ }
+ filedes_close(&file);
+
+ ASSERT(d->digest_size <= FS_VERITY_MAX_DIGEST_SIZE);
+ bin2hex(d->digest, d->digest_size, digest_hex);
+ hash_alg = find_hash_alg_by_num(d->digest_algorithm);
+ if (hash_alg) {
+ hash_alg_name = hash_alg->name;
+ } else {
+ sprintf(_hash_alg_name, "ALG_%u", d->digest_algorithm);
+ hash_alg_name = _hash_alg_name;
+ }
+ printf("%s:%s %s\n", hash_alg_name, digest_hex, argv[i]);
+ }
+ status = 0;
+out:
+ free(d);
+ return status;
+
+out_err:
+ status = 1;
+ goto out;
+
+out_usage:
+ usage(cmd, stderr);
+ status = 2;
+ goto out;
+}
diff --git a/cmd_setup.c b/cmd_setup.c
new file mode 100644
index 0000000..c598a71
--- /dev/null
+++ b/cmd_setup.c
@@ -0,0 +1,565 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * The 'fsverity setup' command
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "commands.h"
+#include "fsverity_uapi.h"
+#include "fsveritysetup.h"
+#include "hash_algs.h"
+
+enum {
+ OPT_HASH,
+ OPT_SALT,
+ OPT_BLOCKSIZE,
+ OPT_SIGNING_KEY,
+ OPT_SIGNING_CERT,
+ OPT_SIGNATURE,
+ OPT_ELIDE,
+ OPT_PATCH,
+};
+
+static const struct option longopts[] = {
+ {"hash", required_argument, NULL, OPT_HASH},
+ {"salt", required_argument, NULL, OPT_SALT},
+ {"blocksize", required_argument, NULL, OPT_BLOCKSIZE},
+ {"signing-key", required_argument, NULL, OPT_SIGNING_KEY},
+ {"signing-cert", required_argument, NULL, OPT_SIGNING_CERT},
+ {"signature", required_argument, NULL, OPT_SIGNATURE},
+ {"elide", required_argument, NULL, OPT_ELIDE},
+ {"patch", required_argument, NULL, OPT_PATCH},
+ {NULL, 0, NULL, 0}
+};
+
+/* Parse the --blocksize=BLOCKSIZE option */
+static bool parse_blocksize_option(const char *opt, int *blocksize_ret)
+{
+ char *end;
+ unsigned long n = strtoul(opt, &end, 10);
+
+ if (n <= 0 || n >= INT32_MAX || *end || !is_power_of_2(n)) {
+ error_msg("Invalid block size: %s. Must be power of 2", opt);
+ return false;
+ }
+ *blocksize_ret = n;
+ return true;
+}
+
+#define FS_VERITY_MAX_LEVELS 64
+
+/*
+ * Calculate the depth of the Merkle tree, then create a map from level to the
+ * block offset at which that level's hash blocks start. Level 'depth - 1' is
+ * the root and is stored first in the file, in the first block following the
+ * original data. Level 0 is the "leaf" level: it's directly "above" the data
+ * blocks and is stored last in the file.
+ */
+static void compute_tree_layout(u64 data_size, u64 tree_offset, int blockbits,
+ unsigned int hashes_per_block,
+ u64 hash_lvl_region_idx[FS_VERITY_MAX_LEVELS],
+ int *depth_ret, u64 *tree_end_ret)
+{
+ u64 blocks = data_size >> blockbits;
+ u64 offset = tree_offset >> blockbits;
+ int depth = 0;
+ int i;
+
+ ASSERT(data_size > 0);
+ ASSERT(data_size % (1 << blockbits) == 0);
+ ASSERT(tree_offset % (1 << blockbits) == 0);
+ ASSERT(hashes_per_block >= 2);
+
+ while (blocks > 1) {
+ ASSERT(depth < FS_VERITY_MAX_LEVELS);
+ blocks = DIV_ROUND_UP(blocks, hashes_per_block);
+ hash_lvl_region_idx[depth++] = blocks;
+ }
+ for (i = depth - 1; i >= 0; i--) {
+ u64 next_count = hash_lvl_region_idx[i];
+
+ hash_lvl_region_idx[i] = offset;
+ offset += next_count;
+ }
+ *depth_ret = depth;
+ *tree_end_ret = offset << blockbits;
+}
+
+/*
+ * Build a Merkle tree (hash tree) over the data of a file.
+ *
+ * @params: Block size, hashes per block, and salt
+ * @hash: Handle for the hash algorithm
+ * @data_file: input data file
+ * @data_size: size of data file in bytes; must be aligned to ->blocksize
+ * @tree_file: output tree file
+ * @tree_offset: byte offset in tree file at which to write the tree;
+ * must be aligned to ->blocksize
+ * @tree_end_ret: On success, the byte offset in the tree file of the end of the
+ * tree is written here
+ * @root_hash_ret: On success, the Merkle tree root hash is written here
+ *
+ * Return: exit status code (0 on success, nonzero on failure)
+ */
+static int build_merkle_tree(const struct fsveritysetup_params *params,
+ struct hash_ctx *hash,
+ struct filedes *data_file, u64 data_size,
+ struct filedes *tree_file, u64 tree_offset,
+ u64 *tree_end_ret, u8 *root_hash_ret)
+{
+ const unsigned int digest_size = hash->alg->digest_size;
+ int depth;
+ u64 hash_lvl_region_idx[FS_VERITY_MAX_LEVELS];
+ u8 *data_to_hash = NULL;
+ u8 *pending_hashes = NULL;
+ unsigned int pending_hash_bytes;
+ u64 nr_hashes_at_this_lvl;
+ int lvl;
+ int status;
+
+ compute_tree_layout(data_size, tree_offset, params->blockbits,
+ params->hashes_per_block, hash_lvl_region_idx,
+ &depth, tree_end_ret);
+
+ /* Allocate block buffers */
+ data_to_hash = xmalloc(params->blocksize);
+ pending_hashes = xmalloc(params->blocksize);
+ pending_hash_bytes = 0;
+ nr_hashes_at_this_lvl = data_size >> params->blockbits;
+
+ /*
+ * Generate each level of the Merkle tree, starting at the leaf level
+ * ('lvl == 0') and ascending to the root node ('lvl == depth - 1').
+ * Then at the end ('lvl == depth'), calculate the root node's hash.
+ */
+ for (lvl = 0; lvl <= depth; lvl++) {
+ u64 i;
+
+ for (i = 0; i < nr_hashes_at_this_lvl; i++) {
+ struct filedes *file;
+ u64 blk_idx;
+
+ hash_init(hash);
+ hash_update(hash, params->salt, params->saltlen);
+
+ if (lvl == 0) {
+ /* Leaf: hashing a data block */
+ file = data_file;
+ blk_idx = i;
+ } else {
+ /* Non-leaf: hashing a hash block */
+ file = tree_file;
+ blk_idx = hash_lvl_region_idx[lvl - 1] + i;
+ }
+ if (!full_pread(file, data_to_hash, params->blocksize,
+ blk_idx << params->blockbits))
+ goto out_err;
+ hash_update(hash, data_to_hash, params->blocksize);
+
+ hash_final(hash, &pending_hashes[pending_hash_bytes]);
+ pending_hash_bytes += digest_size;
+
+ if (lvl == depth) {
+ /* Root hash */
+ ASSERT(nr_hashes_at_this_lvl == 1);
+ ASSERT(pending_hash_bytes == digest_size);
+ memcpy(root_hash_ret, pending_hashes,
+ digest_size);
+ status = 0;
+ goto out;
+ }
+
+ if (pending_hash_bytes + digest_size > params->blocksize
+ || i + 1 == nr_hashes_at_this_lvl) {
+ /* Flush the pending hash block */
+ memset(&pending_hashes[pending_hash_bytes], 0,
+ params->blocksize - pending_hash_bytes);
+ blk_idx = hash_lvl_region_idx[lvl] +
+ (i / params->hashes_per_block);
+ if (!full_pwrite(tree_file,
+ pending_hashes,
+ params->blocksize,
+ blk_idx << params->blockbits))
+ goto out_err;
+ pending_hash_bytes = 0;
+ }
+ }
+
+ nr_hashes_at_this_lvl = DIV_ROUND_UP(nr_hashes_at_this_lvl,
+ params->hashes_per_block);
+ }
+ ASSERT(0); /* unreachable; should exit via "Root hash" case above */
+out_err:
+ status = 1;
+out:
+ free(data_to_hash);
+ free(pending_hashes);
+ return status;
+}
+
+/*
+ * Append to the buffer @*buf_p an extension (variable-length metadata) item of
+ * type @type, containing the data @ext of length @extlen bytes.
+ */
+void fsverity_append_extension(void **buf_p, int type,
+ const void *ext, size_t extlen)
+{
+ void *buf = *buf_p;
+ struct fsverity_extension *hdr = buf;
+
+ hdr->type = cpu_to_le16(type);
+ hdr->length = cpu_to_le32(sizeof(*hdr) + extlen);
+ hdr->reserved = 0;
+ buf += sizeof(*hdr);
+ memcpy(buf, ext, extlen);
+ buf += extlen;
+ memset(buf, 0, -extlen & 7);
+ buf += -extlen & 7;
+ ASSERT(buf - *buf_p == FSVERITY_EXTLEN(extlen));
+ *buf_p = buf;
+}
+
+/*
+ * Append the authenticated portion of the fs-verity descriptor to 'out', in the
+ * process updating 'hash' with the data written.
+ */
+static int append_fsverity_descriptor(const struct fsveritysetup_params *params,
+ u64 filesize, const u8 *root_hash,
+ struct filedes *out,
+ struct hash_ctx *hash)
+{
+ size_t desc_auth_len;
+ void *buf;
+ struct fsverity_descriptor *desc;
+ u16 auth_ext_count;
+ int status;
+
+ desc_auth_len = sizeof(*desc);
+ desc_auth_len += FSVERITY_EXTLEN(params->hash_alg->digest_size);
+ if (params->saltlen)
+ desc_auth_len += FSVERITY_EXTLEN(params->saltlen);
+ desc_auth_len += total_elide_patch_ext_length(params);
+ desc = buf = xzalloc(desc_auth_len);
+
+ memcpy(desc->magic, FS_VERITY_MAGIC, sizeof(desc->magic));
+ desc->major_version = 1;
+ desc->minor_version = 0;
+ desc->log_data_blocksize = params->blockbits;
+ desc->log_tree_blocksize = params->blockbits;
+ desc->data_algorithm = cpu_to_le16(params->hash_alg -
+ fsverity_hash_algs);
+ desc->tree_algorithm = desc->data_algorithm;
+ desc->orig_file_size = cpu_to_le64(filesize);
+
+ auth_ext_count = 1; /* root hash */
+ if (params->saltlen)
+ auth_ext_count++;
+ auth_ext_count += params->num_elisions_and_patches;
+ desc->auth_ext_count = cpu_to_le16(auth_ext_count);
+
+ buf += sizeof(*desc);
+ fsverity_append_extension(&buf, FS_VERITY_EXT_ROOT_HASH,
+ root_hash, params->hash_alg->digest_size);
+ if (params->saltlen)
+ fsverity_append_extension(&buf, FS_VERITY_EXT_SALT,
+ params->salt, params->saltlen);
+ append_elide_patch_exts(&buf, params);
+ ASSERT(buf - (void *)desc == desc_auth_len);
+
+ hash_update(hash, desc, desc_auth_len);
+ if (!full_write(out, desc, desc_auth_len))
+ goto out_err;
+ status = 0;
+out:
+ free(desc);
+ return status;
+
+out_err:
+ status = 1;
+ goto out;
+}
+
+/*
+ * Append any needed unauthenticated extension items: currently, just possibly a
+ * PKCS7_SIGNATURE item containing the signed file measurement.
+ */
+static int
+append_unauthenticated_extensions(struct filedes *out,
+ const struct fsveritysetup_params *params,
+ const u8 *measurement)
+{
+ u16 unauth_ext_count = 0;
+ struct {
+ __le16 unauth_ext_count;
+ __le16 pad[3];
+ } hdr;
+ bool have_sig = params->signing_key_file || params->signature_file;
+
+ if (have_sig)
+ unauth_ext_count++;
+
+ ASSERT(sizeof(hdr) % 8 == 0);
+ memset(&hdr, 0, sizeof(hdr));
+ hdr.unauth_ext_count = cpu_to_le16(unauth_ext_count);
+
+ if (!full_write(out, &hdr, sizeof(hdr)))
+ return 1;
+
+ if (have_sig)
+ return append_signed_measurement(out, params, measurement);
+
+ return 0;
+}
+
+static int append_footer(struct filedes *out, u64 desc_offset)
+{
+ struct fsverity_footer ftr;
+ u32 offset = (out->pos + sizeof(ftr)) - desc_offset;
+
+ ftr.desc_reverse_offset = cpu_to_le32(offset);
+ memcpy(ftr.magic, FS_VERITY_MAGIC, sizeof(ftr.magic));
+
+ if (!full_write(out, &ftr, sizeof(ftr)))
+ return 1;
+ return 0;
+}
+
+static int fsveritysetup(const char *infile, const char *outfile,
+ const struct fsveritysetup_params *params)
+{
+ struct filedes _in = { .fd = -1 };
+ struct filedes _out = { .fd = -1 };
+ struct filedes _tmp = { .fd = -1 };
+ struct hash_ctx *hash = NULL;
+ struct filedes *in = &_in, *out = &_out, *src;
+ u64 filesize;
+ u64 aligned_filesize;
+ u64 src_filesize;
+ u64 tree_end_offset;
+ u8 root_hash[FS_VERITY_MAX_DIGEST_SIZE];
+ u8 measurement[FS_VERITY_MAX_DIGEST_SIZE];
+ char hash_hex[FS_VERITY_MAX_DIGEST_SIZE * 2 + 1];
+ int status;
+
+ if (!open_file(in, infile, (infile == outfile ? O_RDWR : O_RDONLY), 0))
+ goto out_err;
+
+ if (!get_file_size(in, &filesize))
+ goto out_err;
+
+ if (filesize <= 0) {
+ error_msg("input file is empty: '%s'", infile);
+ goto out_err;
+ }
+
+ if (infile == outfile) {
+ /*
+ * Invoked with one file argument: we're appending verity
+ * metadata to an existing file.
+ */
+ out = in;
+ if (!filedes_seek(out, filesize, SEEK_SET))
+ goto out_err;
+ } else {
+ /*
+ * Invoked with two file arguments: we're copying the first file
+ * to the second file, then appending verity metadata to it.
+ */
+ if (!open_file(out, outfile, O_RDWR|O_CREAT|O_TRUNC, 0644))
+ goto out_err;
+ if (!copy_file_data(in, out, filesize))
+ goto out_err;
+ }
+
+ /* Zero-pad the output file to the next block boundary */
+ aligned_filesize = ALIGN(filesize, params->blocksize);
+ if (!write_zeroes(out, aligned_filesize - filesize))
+ goto out_err;
+
+ if (params->num_elisions_and_patches) {
+ /* Merkle tree is built over temporary elided/patched file */
+ src = &_tmp;
+ if (!apply_elisions_and_patches(params, in, filesize,
+ src, &src_filesize))
+ goto out_err;
+ } else {
+ /* Merkle tree is built over original file */
+ src = out;
+ src_filesize = aligned_filesize;
+ }
+
+ hash = hash_create(params->hash_alg);
+
+ /* Build the file's Merkle tree and calculate its root hash */
+ status = build_merkle_tree(params, hash, src, src_filesize,
+ out, aligned_filesize,
+ &tree_end_offset, root_hash);
+ if (status)
+ goto out;
+ if (!filedes_seek(out, tree_end_offset, SEEK_SET))
+ goto out_err;
+
+ /* Append the additional needed metadata */
+
+ hash_init(hash);
+ status = append_fsverity_descriptor(params, filesize, root_hash,
+ out, hash);
+ if (status)
+ goto out;
+ hash_final(hash, measurement);
+
+ status = append_unauthenticated_extensions(out, params, measurement);
+ if (status)
+ goto out;
+
+ status = append_footer(out, tree_end_offset);
+ if (status)
+ goto out;
+
+ bin2hex(measurement, params->hash_alg->digest_size, hash_hex);
+ printf("File measurement: %s:%s\n", params->hash_alg->name, hash_hex);
+ status = 0;
+out:
+ hash_free(hash);
+ if (status != 0 && out->fd >= 0) {
+ /* Error occurred; undo what we wrote */
+ if (in == out)
+ (void)ftruncate(out->fd, filesize);
+ else
+ out->autodelete = true;
+ }
+ filedes_close(&_in);
+ filedes_close(&_tmp);
+ if (!filedes_close(&_out) && status == 0)
+ status = 1;
+ return status;
+
+out_err:
+ status = 1;
+ goto out;
+}
+
+int fsverity_cmd_setup(const struct fsverity_command *cmd,
+ int argc, char *argv[])
+{
+ struct fsveritysetup_params params = {
+ .hash_alg = DEFAULT_HASH_ALG,
+ };
+ STRING_LIST(elide_opts);
+ STRING_LIST(patch_opts);
+ int c;
+ int status;
+
+ while ((c = getopt_long(argc, argv, "", longopts, NULL)) != -1) {
+ switch (c) {
+ case OPT_HASH:
+ params.hash_alg = find_hash_alg_by_name(optarg);
+ if (!params.hash_alg)
+ goto out_usage;
+ break;
+ case OPT_SALT:
+ if (params.salt) {
+ error_msg("--salt can only be specified once");
+ goto out_usage;
+ }
+ params.saltlen = strlen(optarg) / 2;
+ params.salt = xmalloc(params.saltlen);
+ if (!hex2bin(optarg, params.salt, params.saltlen)) {
+ error_msg("salt is not a valid hex string");
+ goto out_usage;
+ }
+ break;
+ case OPT_BLOCKSIZE:
+ if (!parse_blocksize_option(optarg, ¶ms.blocksize))
+ goto out_usage;
+ break;
+ case OPT_SIGNING_KEY:
+ params.signing_key_file = optarg;
+ break;
+ case OPT_SIGNING_CERT:
+ params.signing_cert_file = optarg;
+ break;
+ case OPT_SIGNATURE:
+ params.signature_file = optarg;
+ break;
+ case OPT_ELIDE:
+ string_list_append(&elide_opts, optarg);
+ break;
+ case OPT_PATCH:
+ string_list_append(&patch_opts, optarg);
+ break;
+ default:
+ goto out_usage;
+ }
+ }
+
+ argv += optind;
+ argc -= optind;
+
+ if (argc != 1 && argc != 2)
+ goto out_usage;
+
+ ASSERT(params.hash_alg->digest_size <= FS_VERITY_MAX_DIGEST_SIZE);
+
+ if (params.blocksize == 0) {
+ params.blocksize = sysconf(_SC_PAGESIZE);
+ if (params.blocksize <= 0 || !is_power_of_2(params.blocksize)) {
+ fprintf(stderr,
+ "Warning: invalid _SC_PAGESIZE (%d). Assuming 4K blocks.\n",
+ params.blocksize);
+ params.blocksize = 4096;
+ }
+ }
+ params.blockbits = ilog2(params.blocksize);
+
+ params.hashes_per_block = params.blocksize /
+ params.hash_alg->digest_size;
+ if (params.hashes_per_block < 2) {
+ error_msg("block size of %d bytes is too small for %s hash",
+ params.blocksize, params.hash_alg->name);
+ goto out_err;
+ }
+
+ if (params.signing_cert_file && !params.signing_key_file) {
+ error_msg("--signing-cert was given, but --signing-key was not.\n"
+" You must provide the certificate's private key file using --signing-key.");
+ goto out_err;
+ }
+
+ if ((params.signing_key_file || params.signature_file) &&
+ !params.hash_alg->cryptographic) {
+ error_msg("Signing a file using '%s' checksums does not make sense\n"
+ " because '%s' is not a cryptographically secure hash algorithm.",
+ params.hash_alg->name, params.hash_alg->name);
+ goto out_err;
+ }
+
+ if (!load_elisions_and_patches(&elide_opts, &patch_opts, ¶ms))
+ goto out_err;
+
+ status = fsveritysetup(argv[0], argv[argc - 1], ¶ms);
+out:
+ free(params.salt);
+ free_elisions_and_patches(¶ms);
+ string_list_destroy(&elide_opts);
+ string_list_destroy(&patch_opts);
+ return status;
+
+out_err:
+ status = 1;
+ goto out;
+
+out_usage:
+ usage(cmd, stderr);
+ status = 2;
+ goto out;
+}
diff --git a/commands.h b/commands.h
new file mode 100644
index 0000000..cc87368
--- /dev/null
+++ b/commands.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef COMMANDS_H
+#define COMMANDS_H
+
+#include <stdio.h>
+
+#include "util.h"
+
+struct fsverity_command;
+
+void usage(const struct fsverity_command *cmd, FILE *fp);
+
+int fsverity_cmd_enable(const struct fsverity_command *cmd,
+ int argc, char *argv[]);
+int fsverity_cmd_setup(const struct fsverity_command *cmd,
+ int argc, char *argv[]);
+int fsverity_cmd_measure(const struct fsverity_command *cmd,
+ int argc, char *argv[]);
+
+#endif /* COMMANDS_H */
diff --git a/crc32c_table.h b/crc32c_table.h
new file mode 100644
index 0000000..4c3dafb
--- /dev/null
+++ b/crc32c_table.h
@@ -0,0 +1,72 @@
+/*
+ * crc32c_table.h - data table to accelerate CRC-32C computation
+ *
+ * This file was automatically generated by scripts/gen_crc32c_table.c
+ */
+
+static const u32 crc32c_table[] = {
+ 0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4,
+ 0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb,
+ 0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b,
+ 0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24,
+ 0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b,
+ 0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
+ 0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54,
+ 0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b,
+ 0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a,
+ 0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35,
+ 0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5,
+ 0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
+ 0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45,
+ 0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a,
+ 0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a,
+ 0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595,
+ 0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48,
+ 0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
+ 0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687,
+ 0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198,
+ 0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927,
+ 0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38,
+ 0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8,
+ 0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
+ 0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096,
+ 0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789,
+ 0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859,
+ 0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46,
+ 0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9,
+ 0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
+ 0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36,
+ 0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829,
+ 0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c,
+ 0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93,
+ 0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043,
+ 0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
+ 0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3,
+ 0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc,
+ 0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c,
+ 0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033,
+ 0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652,
+ 0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
+ 0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d,
+ 0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982,
+ 0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d,
+ 0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622,
+ 0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2,
+ 0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
+ 0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530,
+ 0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f,
+ 0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff,
+ 0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0,
+ 0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f,
+ 0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
+ 0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90,
+ 0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f,
+ 0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee,
+ 0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1,
+ 0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321,
+ 0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
+ 0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81,
+ 0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e,
+ 0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e,
+ 0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351,
+};
diff --git a/debian/changelog b/debian/changelog
new file mode 100644
index 0000000..a2e894d
--- /dev/null
+++ b/debian/changelog
@@ -0,0 +1,5 @@
+fsverity-utils (0.1-1) experimental; urgency=low
+
+ * Experimental: debian package for xfstests test appliances
+
+ -- Eric Biggers <ebiggers@google.com> Mon, 02 Apr 2018 10:18:21 -0700
diff --git a/debian/compat b/debian/compat
new file mode 100644
index 0000000..f599e28
--- /dev/null
+++ b/debian/compat
@@ -0,0 +1 @@
+10
diff --git a/debian/control b/debian/control
new file mode 100644
index 0000000..aaa4ac3
--- /dev/null
+++ b/debian/control
@@ -0,0 +1,14 @@
+Source: fsverity-utils
+Priority: optional
+Maintainer: Eric Biggers <ebiggers@google.com>
+Build-Depends: debhelper (>= 10), libssl-dev (>= 1.0.0)
+Standards-Version: 4.0.0
+Vcs-Git: git://git.kernel.org/pub/scm/linux/kernel/git/mhalcrow/fsverity
+
+Package: fsverity-utils
+Section: utils
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: fs-verity userspace utility. This program allows you to set up
+ read-only, integrity and/or authenticity-protected files when supported by the
+ underlying filesystem.
diff --git a/debian/copyright b/debian/copyright
new file mode 100644
index 0000000..a728656
--- /dev/null
+++ b/debian/copyright
@@ -0,0 +1,7 @@
+Format: http://dep.debian.net/deps/dep5
+Upstream-Name: fsverity
+Source: git://git.kernel.org/pub/scm/linux/kernel/git/mhalcrow/fsverity
+
+Files: *
+Copyright: 2018 Google LLC
+License: GPL-2+
diff --git a/debian/rules b/debian/rules
new file mode 100755
index 0000000..9b694a1
--- /dev/null
+++ b/debian/rules
@@ -0,0 +1,8 @@
+#!/usr/bin/make -f
+
+export DH_VERBOSE=1
+
+include /usr/share/dpkg/default.mk
+
+%:
+ dh $@
diff --git a/elide_patch.c b/elide_patch.c
new file mode 100644
index 0000000..3eed416
--- /dev/null
+++ b/elide_patch.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Elide and patch handling for 'fsverity setup'
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fsverity_uapi.h"
+#include "fsveritysetup.h"
+
+/* An elision or a patch */
+struct fsverity_elide_patch {
+ u64 offset; /* byte offset within the original data */
+ u64 length; /* length in bytes */
+ bool patch; /* false if elision, true if patch */
+ u8 data[]; /* replacement data (if patch=true) */
+};
+
+/* Maximum supported patch size, in bytes */
+#define FS_VERITY_MAX_PATCH_SIZE 255
+
+/* Parse an --elide=OFFSET,LENGTH option */
+static struct fsverity_elide_patch *parse_elide_option(const char *optarg)
+{
+ struct fsverity_elide_patch *ext = NULL;
+ char *sep, *end;
+ unsigned long long offset;
+ unsigned long long length;
+
+ sep = strchr(optarg, ',');
+ if (!sep || sep == optarg)
+ goto invalid;
+ errno = 0;
+ *sep = '\0';
+ offset = strtoull(optarg, &end, 10);
+ *sep = ',';
+ if (errno || end != sep)
+ goto invalid;
+ length = strtoull(sep + 1, &end, 10);
+ if (errno || *end)
+ goto invalid;
+ if (length <= 0 || length > UINT64_MAX - offset) {
+ error_msg("Invalid length in '--elide=%s'", optarg);
+ return NULL;
+ }
+ ext = xzalloc(sizeof(*ext));
+ ext->offset = offset;
+ ext->length = length;
+ ext->patch = false;
+ return ext;
+
+invalid:
+ error_msg("Invalid --elide option: '%s'. Must be formatted as OFFSET,LENGTH",
+ optarg);
+ return NULL;
+}
+
+/* Parse a --patch=OFFSET,PATCHFILE option */
+static struct fsverity_elide_patch *parse_patch_option(const char *optarg)
+{
+ struct fsverity_elide_patch *ext = NULL;
+ struct filedes patchfile = { .fd = -1 };
+ char *sep, *end;
+ unsigned long long offset;
+ u64 length;
+
+ sep = strchr(optarg, ',');
+ if (!sep || sep == optarg)
+ goto invalid;
+ errno = 0;
+ *sep = '\0';
+ offset = strtoull(optarg, &end, 10);
+ *sep = ',';
+ if (errno || end != sep)
+ goto invalid;
+ if (!open_file(&patchfile, sep + 1, O_RDONLY, 0))
+ goto out;
+ if (!get_file_size(&patchfile, &length))
+ goto out;
+ if (length <= 0) {
+ error_msg("patch file '%s' is empty", patchfile.name);
+ goto out;
+ }
+ if (length > FS_VERITY_MAX_PATCH_SIZE) {
+ error_msg("Patch file '%s' is too long. Max patch size is %d bytes.",
+ patchfile.name, FS_VERITY_MAX_PATCH_SIZE);
+ goto out;
+ }
+ ext = xzalloc(sizeof(*ext) + length);
+ ext->offset = offset;
+ ext->length = length;
+ ext->patch = true;
+ if (!full_read(&patchfile, ext->data, length)) {
+ free(ext);
+ ext = NULL;
+ }
+out:
+ filedes_close(&patchfile);
+ return ext;
+
+invalid:
+ error_msg("Invalid --patch option: '%s'. Must be formatted as OFFSET,PATCHFILE",
+ optarg);
+ goto out;
+}
+
+/* Sort by increasing offset */
+static int cmp_elide_patch_exts(const void *_p1, const void *_p2)
+{
+ const struct fsverity_elide_patch *ext1, *ext2;
+
+ ext1 = *(const struct fsverity_elide_patch **)_p1;
+ ext2 = *(const struct fsverity_elide_patch **)_p2;
+
+ if (ext1->offset > ext2->offset)
+ return 1;
+ if (ext1->offset < ext2->offset)
+ return -1;
+ return 0;
+}
+
+/*
+ * Given the lists of --elide and --patch options, validate and load the
+ * elisions and patches into @params.
+ */
+bool load_elisions_and_patches(const struct string_list *elide_opts,
+ const struct string_list *patch_opts,
+ struct fsveritysetup_params *params)
+{
+ const size_t num_exts = elide_opts->length + patch_opts->length;
+ struct fsverity_elide_patch **exts;
+ size_t i, j;
+
+ if (num_exts == 0) /* Normal case: no elisions or patches */
+ return true;
+ params->num_elisions_and_patches = num_exts;
+ exts = xzalloc(num_exts * sizeof(exts[0]));
+ params->elisions_and_patches = exts;
+ j = 0;
+
+ /* Parse the --elide options */
+ for (i = 0; i < elide_opts->length; i++) {
+ exts[j] = parse_elide_option(elide_opts->strings[i]);
+ if (!exts[j++])
+ return false;
+ }
+
+ /* Parse the --patch options */
+ for (i = 0; i < patch_opts->length; i++) {
+ exts[j] = parse_patch_option(patch_opts->strings[i]);
+ if (!exts[j++])
+ return false;
+ }
+
+ /* Sort the elisions and patches by increasing offset */
+ qsort(exts, num_exts, sizeof(exts[0]), cmp_elide_patch_exts);
+
+ /* Verify that no elisions or patches overlap */
+ for (j = 1; j < num_exts; j++) {
+ if (exts[j]->offset <
+ exts[j - 1]->offset + exts[j - 1]->length) {
+ error_msg("%s at [%"PRIu64", %"PRIu64") overlaps "
+ "%s at [%"PRIu64", %"PRIu64")",
+ exts[j - 1]->patch ? "Patch" : "Elision",
+ exts[j - 1]->offset,
+ exts[j - 1]->offset + exts[j - 1]->length,
+ exts[j]->patch ? "patch" : "elision",
+ exts[j]->offset,
+ exts[j]->offset + exts[j]->length);
+ return false;
+ }
+ }
+ return true;
+}
+
+void free_elisions_and_patches(struct fsveritysetup_params *params)
+{
+ size_t i;
+
+ for (i = 0; i < params->num_elisions_and_patches; i++)
+ free(params->elisions_and_patches[i]);
+ free(params->elisions_and_patches);
+}
+
+/*
+ * Given the original file @in of length @in_length bytes, create a temporary
+ * file @out_ret and write to it the data with the elisions and patches applied,
+ * with the end zero-padded to the next block boundary. Returns in
+ * @out_length_ret the length of the elided/patched file in bytes.
+ */
+bool apply_elisions_and_patches(const struct fsveritysetup_params *params,
+ struct filedes *in, u64 in_length,
+ struct filedes *out_ret, u64 *out_length_ret)
+{
+ struct fsverity_elide_patch **exts = params->elisions_and_patches;
+ struct filedes *out = out_ret;
+ size_t i;
+
+ for (i = 0; i < params->num_elisions_and_patches; i++) {
+ if (exts[i]->offset + exts[i]->length > in_length) {
+ error_msg("%s at [%"PRIu64", %"PRIu64") extends beyond end of input file",
+ exts[i]->patch ? "Patch" : "Elision",
+ exts[i]->offset,
+ exts[i]->offset + exts[i]->length);
+ return false;
+ }
+ }
+
+ if (!filedes_seek(in, 0, SEEK_SET))
+ return false;
+
+ if (!open_tempfile(out))
+ return false;
+
+ for (i = 0; i < params->num_elisions_and_patches; i++) {
+ printf("Applying %s: offset=%"PRIu64", length=%"PRIu64"\n",
+ exts[i]->patch ? "patch" : "elision",
+ exts[i]->offset, exts[i]->length);
+
+ if (!copy_file_data(in, out, exts[i]->offset - in->pos))
+ return false;
+
+ if (exts[i]->patch &&
+ !full_write(out, exts[i]->data, exts[i]->length))
+ return false;
+
+ if (!filedes_seek(in, exts[i]->length, SEEK_CUR))
+ return false;
+ }
+ if (!copy_file_data(in, out, in_length - in->pos))
+ return false;
+ if (!write_zeroes(out, ALIGN(out->pos, params->blocksize) - out->pos))
+ return false;
+ *out_length_ret = out->pos;
+ return true;
+}
+
+/* Calculate the size the elisions and patches will take up when serialized */
+size_t total_elide_patch_ext_length(const struct fsveritysetup_params *params)
+{
+ size_t total = 0;
+ size_t i;
+
+ for (i = 0; i < params->num_elisions_and_patches; i++) {
+ const struct fsverity_elide_patch *ext =
+ params->elisions_and_patches[i];
+ size_t inner_len;
+
+ if (ext->patch) {
+ inner_len = sizeof(struct fsverity_extension_patch) +
+ ext->length;
+ } else {
+ inner_len = sizeof(struct fsverity_extension_elide);
+ }
+ total += FSVERITY_EXTLEN(inner_len);
+ }
+ return total;
+}
+
+/*
+ * Append the elide and patch extensions (if any) to the given buffer.
+ * The buffer must have enough space; call total_elide_patch_ext_length() first.
+ */
+void append_elide_patch_exts(void **buf_p,
+ const struct fsveritysetup_params *params)
+{
+ void *buf = *buf_p;
+ size_t i;
+ union {
+ struct {
+ struct fsverity_extension_patch hdr;
+ u8 data[FS_VERITY_MAX_PATCH_SIZE];
+ } patch;
+ struct fsverity_extension_elide elide;
+ } u;
+
+ for (i = 0; i < params->num_elisions_and_patches; i++) {
+ const struct fsverity_elide_patch *ext =
+ params->elisions_and_patches[i];
+ int type;
+ size_t extlen;
+
+ if (ext->patch) {
+ type = FS_VERITY_EXT_PATCH;
+ u.patch.hdr.offset = cpu_to_le64(ext->offset);
+ ASSERT(ext->length <= sizeof(u.patch.data));
+ memcpy(u.patch.data, ext->data, ext->length);
+ extlen = sizeof(u.patch.hdr) + ext->length;
+ } else {
+ type = FS_VERITY_EXT_ELIDE;
+ u.elide.offset = cpu_to_le64(ext->offset),
+ u.elide.length = cpu_to_le64(ext->length);
+ extlen = sizeof(u.elide);
+ }
+ fsverity_append_extension(&buf, type, &u, extlen);
+ }
+
+ *buf_p = buf;
+}
diff --git a/fsverity.c b/fsverity.c
new file mode 100644
index 0000000..a463c7f
--- /dev/null
+++ b/fsverity.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * fs-verity userspace tool
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "commands.h"
+#include "hash_algs.h"
+
+static const struct fsverity_command {
+ const char *name;
+ int (*func)(const struct fsverity_command *cmd, int argc, char *argv[]);
+ const char *short_desc;
+ const char *usage_str;
+} fsverity_commands[] = {
+ {
+ .name = "enable",
+ .func = fsverity_cmd_enable,
+ .short_desc =
+"Enable fs-verity on a file with verity metadata",
+ .usage_str =
+" fsverity enable FILE\n"
+ }, {
+ .name = "measure",
+ .func = fsverity_cmd_measure,
+ .short_desc =
+"Display the measurement of the given fs-verity file(s)",
+ .usage_str =
+" fsverity measure FILE...\n"
+ }, {
+ .name = "setup",
+ .func = fsverity_cmd_setup,
+ .short_desc = "Create the verity metadata for a file",
+ .usage_str =
+" fsverity setup INFILE [OUTFILE]\n"
+" [--hash=HASH_ALG] [--salt=SALT] [--signing-key=KEYFILE]\n"
+" [--signing-cert=CERTFILE] [--signature=SIGFILE]\n"
+" [--patch=OFFSET,PATCHFILE] [--elide=OFFSET,LENGTH]\n"
+ }
+};
+
+static void usage_all(FILE *fp)
+{
+ int i;
+
+ fputs("Usage:\n", fp);
+ for (i = 0; i < ARRAY_SIZE(fsverity_commands); i++)
+ fprintf(fp, " %s:\n%s\n", fsverity_commands[i].short_desc,
+ fsverity_commands[i].usage_str);
+ fputs(
+" Standard options:\n"
+" fsverity --help\n"
+" fsverity --version\n"
+"\n"
+"Available hash algorithms: ", fp);
+ show_all_hash_algs(fp);
+ fputs("\nSee `man fsverity` for more details.\n", fp);
+}
+
+static void usage_cmd(const struct fsverity_command *cmd, FILE *fp)
+{
+ fprintf(fp, "Usage:\n%s", cmd->usage_str);
+}
+
+void usage(const struct fsverity_command *cmd, FILE *fp)
+{
+ if (cmd)
+ usage_cmd(cmd, fp);
+ else
+ usage_all(fp);
+}
+
+#define PACKAGE_VERSION "v0.0-alpha"
+#define PACKAGE_BUGREPORT "linux-fscrypt@vger.kernel.org"
+
+static void show_version(void)
+{
+ static const char * const str =
+"fsverity " PACKAGE_VERSION "\n"
+"Copyright (C) 2018 Google LLC\n"
+"License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>.\n"
+"This is free software: you are free to change and redistribute it.\n"
+"There is NO WARRANTY, to the extent permitted by law.\n"
+"\n"
+"Report bugs to " PACKAGE_BUGREPORT ".\n";
+ fputs(str, stdout);
+}
+
+static void handle_common_options(int argc, char *argv[],
+ const struct fsverity_command *cmd)
+{
+ int i;
+
+ for (i = 1; i < argc; i++) {
+ const char *arg = argv[i];
+
+ if (*arg++ != '-')
+ continue;
+ if (*arg++ != '-')
+ continue;
+ if (!strcmp(arg, "help")) {
+ usage(cmd, stdout);
+ exit(0);
+ } else if (!strcmp(arg, "version")) {
+ show_version();
+ exit(0);
+ } else if (!*arg) /* reached "--", no more options */
+ return;
+ }
+}
+
+static const struct fsverity_command *find_command(const char *name)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(fsverity_commands); i++)
+ if (!strcmp(name, fsverity_commands[i].name))
+ return &fsverity_commands[i];
+ return NULL;
+}
+
+int main(int argc, char *argv[])
+{
+ const struct fsverity_command *cmd;
+
+ if (argc < 2) {
+ error_msg("no command specified");
+ usage_all(stderr);
+ return 2;
+ }
+
+ cmd = find_command(argv[1]);
+
+ handle_common_options(argc, argv, cmd);
+
+ if (!cmd) {
+ error_msg("unrecognized command: '%s'", argv[1]);
+ usage_all(stderr);
+ return 2;
+ }
+ return cmd->func(cmd, argc - 1, argv + 1);
+}
diff --git a/fsverity_uapi.h b/fsverity_uapi.h
new file mode 100644
index 0000000..00c64f9
--- /dev/null
+++ b/fsverity_uapi.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * fs-verity (file-based verity) support
+ *
+ * Copyright (C) 2018 Google LLC
+ */
+#ifndef _UAPI_LINUX_FSVERITY_H
+#define _UAPI_LINUX_FSVERITY_H
+
+#include <linux/limits.h>
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/* ========== Ioctls ========== */
+
+struct fsverity_digest {
+ __u16 digest_algorithm;
+ __u16 digest_size; /* input/output */
+ __u8 digest[];
+};
+
+#define FS_IOC_ENABLE_VERITY _IO('f', 133)
+#define FS_IOC_MEASURE_VERITY _IOWR('f', 134, struct fsverity_digest)
+
+/* ========== On-disk format ========== */
+
+#define FS_VERITY_MAGIC "FSVerity"
+
+/* Supported hash algorithms */
+#define FS_VERITY_ALG_SHA256 1
+#define FS_VERITY_ALG_SHA512 2
+#define FS_VERITY_ALG_CRC32C 3 /* for integrity only */
+
+/* Metadata stored near the end of fs-verity files, after the Merkle tree */
+/* This structure is 64 bytes long */
+struct fsverity_descriptor {
+ __u8 magic[8]; /* must be FS_VERITY_MAGIC */
+ __u8 major_version; /* must be 1 */
+ __u8 minor_version; /* must be 0 */
+ __u8 log_data_blocksize;/* log2(data-bytes-per-hash), e.g. 12 for 4KB */
+ __u8 log_tree_blocksize;/* log2(tree-bytes-per-hash), e.g. 12 for 4KB */
+ __le16 data_algorithm; /* hash algorithm for data blocks */
+ __le16 tree_algorithm; /* hash algorithm for tree blocks */
+ __le32 flags; /* flags */
+ __le32 reserved1; /* must be 0 */
+ __le64 orig_file_size; /* size of the original, unpadded data */
+ __le16 auth_ext_count; /* number of authenticated extensions */
+ __u8 reserved2[30]; /* must be 0 */
+};
+/* followed by list of 'auth_ext_count' authenticated extensions */
+/*
+ * then followed by '__le16 unauth_ext_count' padded to next 8-byte boundary,
+ * then a list of 'unauth_ext_count' (may be 0) unauthenticated extensions
+ */
+
+/* Extension types */
+#define FS_VERITY_EXT_ROOT_HASH 1
+#define FS_VERITY_EXT_SALT 2
+#define FS_VERITY_EXT_PKCS7_SIGNATURE 3
+#define FS_VERITY_EXT_ELIDE 4
+#define FS_VERITY_EXT_PATCH 5
+
+/* Header of each extension (variable-length metadata item) */
+struct fsverity_extension {
+ /*
+ * Length in bytes, including this header but excluding padding to next
+ * 8-byte boundary that is applied when advancing to the next extension.
+ */
+ __le32 length;
+ __le16 type; /* Type of this extension (see codes above) */
+ __le16 reserved; /* Reserved, must be 0 */
+};
+/* followed by the payload of 'length - 8' bytes */
+
+/* Extension payload formats */
+
+/*
+ * FS_VERITY_EXT_ROOT_HASH payload is just a byte array, with size equal to the
+ * digest size of the hash algorithm given in the fsverity_descriptor
+ */
+
+/* FS_VERITY_EXT_SALT payload is just a byte array, any size */
+
+/*
+ * FS_VERITY_EXT_PKCS7_SIGNATURE payload is a DER-encoded PKCS#7 message
+ * containing the signed file measurement in the following format:
+ */
+struct fsverity_digest_disk {
+ __le16 digest_algorithm;
+ __le16 digest_size;
+ __u8 digest[];
+};
+
+/* FS_VERITY_EXT_ELIDE payload */
+struct fsverity_extension_elide {
+ __le64 offset;
+ __le64 length;
+};
+
+/* FS_VERITY_EXT_PATCH payload */
+struct fsverity_extension_patch {
+ __le64 offset;
+ /* followed by variable-length patch data */
+};
+
+/* Fields stored at the very end of the file */
+struct fsverity_footer {
+ __le32 desc_reverse_offset; /* distance to fsverity_descriptor */
+ __u8 magic[8]; /* FS_VERITY_MAGIC */
+} __attribute__((packed));
+
+#endif /* _UAPI_LINUX_FSVERITY_H */
diff --git a/fsveritysetup.h b/fsveritysetup.h
new file mode 100644
index 0000000..282aabd
--- /dev/null
+++ b/fsveritysetup.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef FSVERITYSETUP_H
+#define FSVERITYSETUP_H
+
+#include "util.h"
+
+struct fsveritysetup_params {
+ const struct fsverity_hash_alg *hash_alg;
+ u8 *salt;
+ size_t saltlen;
+ int blocksize;
+ int blockbits; /* ilog2(blocksize) */
+ unsigned int hashes_per_block; /* blocksize / digest_size */
+ const char *signing_key_file;
+ const char *signing_cert_file;
+ const char *signature_file;
+ struct fsverity_elide_patch **elisions_and_patches;
+ size_t num_elisions_and_patches;
+};
+
+void fsverity_append_extension(void **buf_p, int type,
+ const void *ext, size_t extlen);
+
+#define FSVERITY_EXTLEN(inner_len) \
+ ALIGN(sizeof(struct fsverity_extension) + (inner_len), 8)
+
+/* elide_patch.c */
+bool load_elisions_and_patches(const struct string_list *elide_opts,
+ const struct string_list *patch_opts,
+ struct fsveritysetup_params *params);
+void free_elisions_and_patches(struct fsveritysetup_params *params);
+bool apply_elisions_and_patches(const struct fsveritysetup_params *params,
+ struct filedes *in, u64 in_length,
+ struct filedes *out_ret, u64 *out_length_ret);
+size_t total_elide_patch_ext_length(const struct fsveritysetup_params *params);
+void append_elide_patch_exts(void **buf_p,
+ const struct fsveritysetup_params *params);
+/* sign.c */
+int append_signed_measurement(struct filedes *out,
+ const struct fsveritysetup_params *params,
+ const u8 *measurement);
+
+#endif /* FSVERITYSETUP_H */
diff --git a/hash_algs.c b/hash_algs.c
new file mode 100644
index 0000000..1e46924
--- /dev/null
+++ b/hash_algs.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * fs-verity hash algorithms
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <openssl/evp.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fsverity_uapi.h"
+#include "hash_algs.h"
+
+static void free_hash_ctx(struct hash_ctx *ctx)
+{
+ free(ctx);
+}
+
+/* ========== libcrypto (OpenSSL) wrappers ========== */
+
+struct openssl_hash_ctx {
+ struct hash_ctx base; /* must be first */
+ EVP_MD_CTX *md_ctx;
+ const EVP_MD *md;
+};
+
+static void openssl_digest_init(struct hash_ctx *_ctx)
+{
+ struct openssl_hash_ctx *ctx = (void *)_ctx;
+
+ if (EVP_DigestInit_ex(ctx->md_ctx, ctx->md, NULL) != 1)
+ fatal_error("EVP_DigestInit_ex() failed for algorithm '%s'",
+ ctx->base.alg->name);
+}
+
+static void openssl_digest_update(struct hash_ctx *_ctx,
+ const void *data, size_t size)
+{
+ struct openssl_hash_ctx *ctx = (void *)_ctx;
+
+ if (EVP_DigestUpdate(ctx->md_ctx, data, size) != 1)
+ fatal_error("EVP_DigestUpdate() failed for algorithm '%s'",
+ ctx->base.alg->name);
+}
+
+static void openssl_digest_final(struct hash_ctx *_ctx, u8 *digest)
+{
+ struct openssl_hash_ctx *ctx = (void *)_ctx;
+
+ if (EVP_DigestFinal_ex(ctx->md_ctx, digest, NULL) != 1)
+ fatal_error("EVP_DigestFinal_ex() failed for algorithm '%s'",
+ ctx->base.alg->name);
+}
+
+static void openssl_digest_ctx_free(struct hash_ctx *_ctx)
+{
+ struct openssl_hash_ctx *ctx = (void *)_ctx;
+
+ /*
+ * OpenSSL 1.1.0 renamed EVP_MD_CTX_destroy() to EVP_MD_CTX_free() but
+ * kept the old name as a macro. Use the old name for compatibility
+ * with older OpenSSL versions.
+ */
+ EVP_MD_CTX_destroy(ctx->md_ctx);
+ free(ctx);
+}
+
+static struct hash_ctx *
+openssl_digest_ctx_create(const struct fsverity_hash_alg *alg, const EVP_MD *md)
+{
+ struct openssl_hash_ctx *ctx;
+
+ ctx = xzalloc(sizeof(*ctx));
+ ctx->base.alg = alg;
+ ctx->base.init = openssl_digest_init;
+ ctx->base.update = openssl_digest_update;
+ ctx->base.final = openssl_digest_final;
+ ctx->base.free = openssl_digest_ctx_free;
+ /*
+ * OpenSSL 1.1.0 renamed EVP_MD_CTX_create() to EVP_MD_CTX_new() but
+ * kept the old name as a macro. Use the old name for compatibility
+ * with older OpenSSL versions.
+ */
+ ctx->md_ctx = EVP_MD_CTX_create();
+ if (!ctx->md_ctx)
+ fatal_error("out of memory");
+
+ ctx->md = md;
+ ASSERT(EVP_MD_size(md) == alg->digest_size);
+
+ return &ctx->base;
+}
+
+static struct hash_ctx *create_sha256_ctx(const struct fsverity_hash_alg *alg)
+{
+ return openssl_digest_ctx_create(alg, EVP_sha256());
+}
+
+static struct hash_ctx *create_sha512_ctx(const struct fsverity_hash_alg *alg)
+{
+ return openssl_digest_ctx_create(alg, EVP_sha512());
+}
+
+/* ========== CRC-32C ========== */
+
+/*
+ * There are faster ways to calculate CRC's, but for now we just use the
+ * 256-entry table method as it's portable and not too complex.
+ */
+
+#include "crc32c_table.h"
+
+struct crc32c_hash_ctx {
+ struct hash_ctx base; /* must be first */
+ u32 remainder;
+};
+
+static void crc32c_init(struct hash_ctx *_ctx)
+{
+ struct crc32c_hash_ctx *ctx = (void *)_ctx;
+
+ ctx->remainder = ~0;
+}
+
+static void crc32c_update(struct hash_ctx *_ctx, const void *data, size_t size)
+{
+ struct crc32c_hash_ctx *ctx = (void *)_ctx;
+ const u8 *p = data;
+ u32 r = ctx->remainder;
+
+ while (size--)
+ r = (r >> 8) ^ crc32c_table[(u8)r ^ *p++];
+
+ ctx->remainder = r;
+}
+
+static void crc32c_final(struct hash_ctx *_ctx, u8 *digest)
+{
+ struct crc32c_hash_ctx *ctx = (void *)_ctx;
+ __le32 remainder = cpu_to_le32(~ctx->remainder);
+
+ memcpy(digest, &remainder, sizeof(remainder));
+}
+
+static struct hash_ctx *create_crc32c_ctx(const struct fsverity_hash_alg *alg)
+{
+ struct crc32c_hash_ctx *ctx = xzalloc(sizeof(*ctx));
+
+ ctx->base.alg = alg;
+ ctx->base.init = crc32c_init;
+ ctx->base.update = crc32c_update;
+ ctx->base.final = crc32c_final;
+ ctx->base.free = free_hash_ctx;
+ return &ctx->base;
+}
+
+/* ========== Hash algorithm definitions ========== */
+
+const struct fsverity_hash_alg fsverity_hash_algs[] = {
+ [FS_VERITY_ALG_SHA256] = {
+ .name = "sha256",
+ .digest_size = 32,
+ .cryptographic = true,
+ .create_ctx = create_sha256_ctx,
+ },
+ [FS_VERITY_ALG_SHA512] = {
+ .name = "sha512",
+ .digest_size = 64,
+ .cryptographic = true,
+ .create_ctx = create_sha512_ctx,
+ },
+ [FS_VERITY_ALG_CRC32C] = {
+ .name = "crc32c",
+ .digest_size = 4,
+ .create_ctx = create_crc32c_ctx,
+ },
+};
+
+const struct fsverity_hash_alg *find_hash_alg_by_name(const char *name)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(fsverity_hash_algs); i++) {
+ if (fsverity_hash_algs[i].name &&
+ !strcmp(name, fsverity_hash_algs[i].name))
+ return &fsverity_hash_algs[i];
+ }
+ error_msg("unknown hash algorithm: '%s'", name);
+ fputs("Available hash algorithms: ", stderr);
+ show_all_hash_algs(stderr);
+ putc('\n', stderr);
+ return NULL;
+}
+
+const struct fsverity_hash_alg *find_hash_alg_by_num(unsigned int num)
+{
+ if (num < ARRAY_SIZE(fsverity_hash_algs) &&
+ fsverity_hash_algs[num].name)
+ return &fsverity_hash_algs[num];
+
+ return NULL;
+}
+
+void show_all_hash_algs(FILE *fp)
+{
+ int i;
+ const char *sep = "";
+
+ for (i = 0; i < ARRAY_SIZE(fsverity_hash_algs); i++) {
+ if (fsverity_hash_algs[i].name) {
+ fprintf(fp, "%s%s", sep, fsverity_hash_algs[i].name);
+ sep = ", ";
+ }
+ }
+}
diff --git a/hash_algs.h b/hash_algs.h
new file mode 100644
index 0000000..3cb0a98
--- /dev/null
+++ b/hash_algs.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef HASH_ALGS_H
+#define HASH_ALGS_H
+
+#include <stdio.h>
+
+#include "util.h"
+
+struct fsverity_hash_alg {
+ const char *name;
+ unsigned int digest_size;
+ bool cryptographic;
+ struct hash_ctx *(*create_ctx)(const struct fsverity_hash_alg *alg);
+};
+
+extern const struct fsverity_hash_alg fsverity_hash_algs[];
+
+struct hash_ctx {
+ const struct fsverity_hash_alg *alg;
+ void (*init)(struct hash_ctx *ctx);
+ void (*update)(struct hash_ctx *ctx, const void *data, size_t size);
+ void (*final)(struct hash_ctx *ctx, u8 *out);
+ void (*free)(struct hash_ctx *ctx);
+};
+
+const struct fsverity_hash_alg *find_hash_alg_by_name(const char *name);
+const struct fsverity_hash_alg *find_hash_alg_by_num(unsigned int num);
+void show_all_hash_algs(FILE *fp);
+#define DEFAULT_HASH_ALG (&fsverity_hash_algs[FS_VERITY_ALG_SHA256])
+
+/*
+ * Largest digest size among all hash algorithms supported by fs-verity.
+ * This can be increased if needed.
+ */
+#define FS_VERITY_MAX_DIGEST_SIZE 64
+
+static inline struct hash_ctx *hash_create(const struct fsverity_hash_alg *alg)
+{
+ return alg->create_ctx(alg);
+}
+
+static inline void hash_init(struct hash_ctx *ctx)
+{
+ ctx->init(ctx);
+}
+
+static inline void hash_update(struct hash_ctx *ctx,
+ const void *data, size_t size)
+{
+ ctx->update(ctx, data, size);
+}
+
+static inline void hash_final(struct hash_ctx *ctx, u8 *digest)
+{
+ ctx->final(ctx, digest);
+}
+
+static inline void hash_free(struct hash_ctx *ctx)
+{
+ if (ctx)
+ ctx->free(ctx);
+}
+
+#endif /* HASH_ALGS_H */
diff --git a/scripts/gen_crc32c_table.c b/scripts/gen_crc32c_table.c
new file mode 100644
index 0000000..1c5af88
--- /dev/null
+++ b/scripts/gen_crc32c_table.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Generate a table for CRC-32C calculation.
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+
+/*
+ * This is the CRC-32C (Castagnoli) polynomial: x^32+x^28+x^27+x^26+x^25+x^23+
+ * x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+x^8+x^6+x^0, with the polynomial
+ * coefficients mapped to bits using the "little endian" convention.
+ */
+#define CRC32C_POLY_LE 0x82F63B78
+
+static uint32_t crc32c_update_bit(uint32_t remainder, uint8_t bit)
+{
+ return (remainder >> 1) ^
+ (((remainder ^ bit) & 1) ? CRC32C_POLY_LE : 0);
+}
+
+static uint32_t crc32c_update_byte(uint32_t remainder, uint8_t byte)
+{
+ int bit;
+
+ for (bit = 0; bit < 8; bit++, byte >>= 1)
+ remainder = crc32c_update_bit(remainder, byte & 1);
+ return remainder;
+}
+
+static uint32_t crc32c_table[256];
+
+int main(void)
+{
+ int i, j;
+
+ for (i = 0; i < 256; i++)
+ crc32c_table[i] = crc32c_update_byte(0, i);
+
+ printf("/*\n");
+ printf(" * crc32c_table.h - data table to accelerate CRC-32C computation\n");
+ printf(" *\n");
+ printf(" * This file was automatically generated by scripts/gen_crc32c_table.c\n");
+ printf(" */\n");
+ printf("\n");
+ printf("static const u32 crc32c_table[] = {\n");
+ for (i = 0; i < 64; i++) {
+ printf("\t");
+ for (j = 0; j < 4; j++) {
+ printf("0x%08x,", crc32c_table[i * 4 + j]);
+ if (j != 3)
+ printf(" ");
+ }
+ printf("\n");
+ }
+ printf("};\n");
+ return 0;
+}
diff --git a/sign.c b/sign.c
new file mode 100644
index 0000000..20fecfa
--- /dev/null
+++ b/sign.c
@@ -0,0 +1,552 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Signature support for 'fsverity setup'
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <fcntl.h>
+#include <limits.h>
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/pem.h>
+#include <openssl/pkcs7.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fsverity_uapi.h"
+#include "fsveritysetup.h"
+#include "hash_algs.h"
+
+static void __printf(1, 2) __cold
+error_msg_openssl(const char *format, ...)
+{
+ va_list va;
+
+ va_start(va, format);
+ do_error_msg(format, va, 0);
+ va_end(va);
+
+ if (ERR_peek_error() == 0)
+ return;
+
+ fprintf(stderr, "OpenSSL library errors:\n");
+ ERR_print_errors_fp(stderr);
+}
+
+/* Read a PEM PKCS#8 formatted private key */
+static EVP_PKEY *read_private_key(const char *keyfile)
+{
+ BIO *bio;
+ EVP_PKEY *pkey;
+
+ bio = BIO_new_file(keyfile, "r");
+ if (!bio) {
+ error_msg_openssl("can't open '%s' for reading", keyfile);
+ return NULL;
+ }
+
+ pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
+ if (!pkey) {
+ error_msg_openssl("Failed to parse private key file '%s'.\n"
+ " Note: it must be in PEM PKCS#8 format.",
+ keyfile);
+ }
+ BIO_free(bio);
+ return pkey;
+}
+
+/* Read a PEM X.509 formatted certificate */
+static X509 *read_certificate(const char *certfile)
+{
+ BIO *bio;
+ X509 *cert;
+
+ bio = BIO_new_file(certfile, "r");
+ if (!bio) {
+ error_msg_openssl("can't open '%s' for reading", certfile);
+ return NULL;
+ }
+ cert = PEM_read_bio_X509(bio, NULL, NULL, NULL);
+ if (!cert) {
+ error_msg_openssl("Failed to parse X.509 certificate file '%s'.\n"
+ " Note: it must be in PEM format.",
+ certfile);
+ }
+ BIO_free(bio);
+ return cert;
+}
+
+/*
+ * Check that the given data is a valid 'struct fsverity_digest_disk' that
+ * matches the given @expected_digest and @hash_alg.
+ *
+ * Return: NULL if the digests match, else a string describing the difference.
+ */
+static const char *
+compare_fsverity_digest(const void *data, size_t size,
+ const u8 *expected_digest,
+ const struct fsverity_hash_alg *hash_alg)
+{
+ const struct fsverity_digest_disk *d = data;
+
+ if (size != sizeof(*d) + hash_alg->digest_size)
+ return "unexpected length";
+
+ if (le16_to_cpu(d->digest_algorithm) != hash_alg - fsverity_hash_algs)
+ return "unexpected hash algorithm";
+
+ if (le16_to_cpu(d->digest_size) != hash_alg->digest_size)
+ return "wrong digest size for hash algorithm";
+
+ if (memcmp(expected_digest, d->digest, hash_alg->digest_size))
+ return "wrong digest";
+
+ return NULL;
+}
+
+#ifdef OPENSSL_IS_BORINGSSL
+
+static bool sign_pkcs7(const void *data_to_sign, size_t data_size,
+ EVP_PKEY *pkey, X509 *cert, const EVP_MD *md,
+ void **sig_ret, int *sig_size_ret)
+{
+ CBB out, outer_seq, wrapped_seq, seq, digest_algos_set, digest_algo,
+ null, content_info, issuer_and_serial, signed_data,
+ wrapped_signed_data, signer_infos, signer_info, sign_algo,
+ signature;
+ EVP_MD_CTX md_ctx;
+ u8 *name_der = NULL, *sig = NULL, *pkcs7_data = NULL;
+ size_t pkcs7_data_len, sig_len;
+ int name_der_len, sig_nid;
+ bool ok = false;
+
+ EVP_MD_CTX_init(&md_ctx);
+ BIGNUM *serial = ASN1_INTEGER_to_BN(X509_get_serialNumber(cert), NULL);
+
+ if (!CBB_init(&out, 1024)) {
+ error_msg("out of memory");
+ goto out;
+ }
+
+ name_der_len = i2d_X509_NAME(X509_get_subject_name(cert), &name_der);
+ if (name_der_len < 0) {
+ error_msg_openssl("i2d_X509_NAME failed");
+ goto out;
+ }
+
+ if (!EVP_DigestSignInit(&md_ctx, NULL, md, NULL, pkey)) {
+ error_msg_openssl("EVP_DigestSignInit failed");
+ goto out;
+ }
+
+ sig_len = EVP_PKEY_size(pkey);
+ sig = xmalloc(sig_len);
+ if (!EVP_DigestSign(&md_ctx, sig, &sig_len, data_to_sign, data_size)) {
+ error_msg_openssl("EVP_DigestSign failed");
+ goto out;
+ }
+
+ sig_nid = EVP_PKEY_id(pkey);
+ /* To mirror OpenSSL behaviour, always use |NID_rsaEncryption| with RSA
+ * rather than the combined hash+pkey NID. */
+ if (sig_nid != NID_rsaEncryption) {
+ OBJ_find_sigid_by_algs(&sig_nid, EVP_MD_type(md),
+ EVP_PKEY_id(pkey));
+ }
+
+ // See https://tools.ietf.org/html/rfc2315#section-7
+ if (!CBB_add_asn1(&out, &outer_seq, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&outer_seq, NID_pkcs7_signed) ||
+ !CBB_add_asn1(&outer_seq, &wrapped_seq, CBS_ASN1_CONTEXT_SPECIFIC |
+ CBS_ASN1_CONSTRUCTED | 0) ||
+ // See https://tools.ietf.org/html/rfc2315#section-9.1
+ !CBB_add_asn1(&wrapped_seq, &seq, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1_uint64(&seq, 1 /* version */) ||
+ !CBB_add_asn1(&seq, &digest_algos_set, CBS_ASN1_SET) ||
+ !CBB_add_asn1(&digest_algos_set, &digest_algo, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&digest_algo, EVP_MD_type(md)) ||
+ !CBB_add_asn1(&digest_algo, &null, CBS_ASN1_NULL) ||
+ !CBB_add_asn1(&seq, &content_info, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&content_info, NID_pkcs7_data) ||
+ !CBB_add_asn1(
+ &content_info, &signed_data,
+ CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
+ !CBB_add_asn1(&signed_data, &wrapped_signed_data,
+ CBS_ASN1_OCTETSTRING) ||
+ !CBB_add_bytes(&wrapped_signed_data, (const u8 *)data_to_sign,
+ data_size) ||
+ !CBB_add_asn1(&seq, &signer_infos, CBS_ASN1_SET) ||
+ !CBB_add_asn1(&signer_infos, &signer_info, CBS_ASN1_SEQUENCE) ||
+ !CBB_add_asn1_uint64(&signer_info, 1 /* version */) ||
+ !CBB_add_asn1(&signer_info, &issuer_and_serial,
+ CBS_ASN1_SEQUENCE) ||
+ !CBB_add_bytes(&issuer_and_serial, name_der, name_der_len) ||
+ !BN_marshal_asn1(&issuer_and_serial, serial) ||
+ !CBB_add_asn1(&signer_info, &digest_algo, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&digest_algo, EVP_MD_type(md)) ||
+ !CBB_add_asn1(&digest_algo, &null, CBS_ASN1_NULL) ||
+ !CBB_add_asn1(&signer_info, &sign_algo, CBS_ASN1_SEQUENCE) ||
+ !OBJ_nid2cbb(&sign_algo, sig_nid) ||
+ !CBB_add_asn1(&sign_algo, &null, CBS_ASN1_NULL) ||
+ !CBB_add_asn1(&signer_info, &signature, CBS_ASN1_OCTETSTRING) ||
+ !CBB_add_bytes(&signature, sig, sig_len) ||
+ !CBB_finish(&out, &pkcs7_data, &pkcs7_data_len)) {
+ error_msg_openssl("failed to construct PKCS#7 data");
+ goto out;
+ }
+
+ *sig_ret = xmemdup(pkcs7_data, pkcs7_data_len);
+ *sig_size_ret = pkcs7_data_len;
+ ok = true;
+out:
+ BN_free(serial);
+ EVP_MD_CTX_cleanup(&md_ctx);
+ CBB_cleanup(&out);
+ free(sig);
+ OPENSSL_free(name_der);
+ OPENSSL_free(pkcs7_data);
+ return ok;
+}
+
+static const char *
+compare_fsverity_digest_pkcs7(const void *sig, size_t sig_len,
+ const u8 *expected_measurement,
+ const struct fsverity_hash_alg *hash_alg)
+{
+ CBS in, content_info, content_type, wrapped_signed_data, signed_data,
+ content, wrapped_data, data;
+ u64 version;
+
+ CBS_init(&in, sig, sig_len);
+ if (!CBS_get_asn1(&in, &content_info, CBS_ASN1_SEQUENCE) ||
+ !CBS_get_asn1(&content_info, &content_type, CBS_ASN1_OBJECT) ||
+ (OBJ_cbs2nid(&content_type) != NID_pkcs7_signed) ||
+ !CBS_get_asn1(
+ &content_info, &wrapped_signed_data,
+ CBS_ASN1_CONTEXT_SPECIFIC | CBS_ASN1_CONSTRUCTED | 0) ||
+ !CBS_get_asn1(&wrapped_signed_data, &signed_data,
+ CBS_ASN1_SEQUENCE) ||
+ !CBS_get_asn1_uint64(&signed_data, &version) ||
+ (version < 1) ||
+ !CBS_get_asn1(&signed_data, NULL /* digests */, CBS_ASN1_SET) ||
+ !CBS_get_asn1(&signed_data, &content, CBS_ASN1_SEQUENCE) ||
+ !CBS_get_asn1(&content, &content_type, CBS_ASN1_OBJECT) ||
+ (OBJ_cbs2nid(&content_type) != NID_pkcs7_data) ||
+ !CBS_get_asn1(&content, &wrapped_data, CBS_ASN1_CONTEXT_SPECIFIC |
+ CBS_ASN1_CONSTRUCTED | 0) ||
+ !CBS_get_asn1(&wrapped_data, &data, CBS_ASN1_OCTETSTRING)) {
+ return "invalid PKCS#7 data";
+ }
+
+ return compare_fsverity_digest(CBS_data(&data), CBS_len(&data),
+ expected_measurement, hash_alg);
+}
+
+#else /* OPENSSL_IS_BORINGSSL */
+
+static BIO *new_mem_buf(const void *buf, size_t size)
+{
+ BIO *bio;
+
+ ASSERT(size <= INT_MAX);
+ /*
+ * Prior to OpenSSL 1.1.0, BIO_new_mem_buf() took a non-const pointer,
+ * despite still marking the resulting bio as read-only. So cast away
+ * the const to avoid a compiler warning with older OpenSSL versions.
+ */
+ bio = BIO_new_mem_buf((void *)buf, size);
+ if (!bio)
+ error_msg_openssl("out of memory");
+ return bio;
+}
+
+static bool sign_pkcs7(const void *data_to_sign, size_t data_size,
+ EVP_PKEY *pkey, X509 *cert, const EVP_MD *md,
+ void **sig_ret, int *sig_size_ret)
+{
+ /*
+ * PKCS#7 signing flags:
+ *
+ * - PKCS7_BINARY signing binary data, so skip MIME translation
+ *
+ * - PKCS7_NOATTR omit extra authenticated attributes, such as
+ * SMIMECapabilities
+ *
+ * - PKCS7_NOCERTS omit the signer's certificate
+ *
+ * - PKCS7_PARTIAL PKCS7_sign() creates a handle only, then
+ * PKCS7_sign_add_signer() can add a signer later.
+ * This is necessary to change the message digest
+ * algorithm from the default of SHA-1. Requires
+ * OpenSSL 1.0.0 or later.
+ */
+ int pkcs7_flags = PKCS7_BINARY | PKCS7_NOATTR | PKCS7_NOCERTS |
+ PKCS7_PARTIAL;
+ void *sig;
+ int sig_size;
+ BIO *bio = NULL;
+ PKCS7 *p7 = NULL;
+ bool ok = false;
+
+ bio = new_mem_buf(data_to_sign, data_size);
+ if (!bio)
+ goto out;
+
+ p7 = PKCS7_sign(NULL, NULL, NULL, bio, pkcs7_flags);
+ if (!p7) {
+ error_msg_openssl("failed to initialize PKCS#7 signature object");
+ goto out;
+ }
+
+ if (!PKCS7_sign_add_signer(p7, cert, pkey, md, pkcs7_flags)) {
+ error_msg_openssl("failed to add signer to PKCS#7 signature object");
+ goto out;
+ }
+
+ if (PKCS7_final(p7, bio, pkcs7_flags) != 1) {
+ error_msg_openssl("failed to finalize PKCS#7 signature");
+ goto out;
+ }
+
+ BIO_free(bio);
+ bio = BIO_new(BIO_s_mem());
+ if (!bio) {
+ error_msg_openssl("out of memory");
+ goto out;
+ }
+
+ if (i2d_PKCS7_bio(bio, p7) != 1) {
+ error_msg_openssl("failed to DER-encode PKCS#7 signature object");
+ goto out;
+ }
+
+ sig_size = BIO_get_mem_data(bio, &sig);
+ *sig_ret = xmemdup(sig, sig_size);
+ *sig_size_ret = sig_size;
+ ok = true;
+out:
+ PKCS7_free(p7);
+ BIO_free(bio);
+ return ok;
+}
+
+static const char *
+compare_fsverity_digest_pkcs7(const void *sig, size_t sig_len,
+ const u8 *expected_measurement,
+ const struct fsverity_hash_alg *hash_alg)
+{
+ BIO *bio = NULL;
+ PKCS7 *p7 = NULL;
+ const char *reason = NULL;
+
+ bio = new_mem_buf(sig, sig_len);
+ if (!bio)
+ return "out of memory";
+
+ p7 = d2i_PKCS7_bio(bio, NULL);
+ if (!p7) {
+ reason = "failed to decode PKCS#7 signature";
+ goto out;
+ }
+
+ if (OBJ_obj2nid(p7->type) != NID_pkcs7_signed ||
+ OBJ_obj2nid(p7->d.sign->contents->type) != NID_pkcs7_data) {
+ reason = "unexpected PKCS#7 content type";
+ } else {
+ const ASN1_OCTET_STRING *o = p7->d.sign->contents->d.data;
+
+ reason = compare_fsverity_digest(o->data, o->length,
+ expected_measurement,
+ hash_alg);
+ }
+out:
+ BIO_free(bio);
+ PKCS7_free(p7);
+ return reason;
+}
+
+#endif /* !OPENSSL_IS_BORINGSSL */
+
+/*
+ * Sign the specified @data_to_sign of length @data_size bytes using the private
+ * key in @keyfile, the certificate in @certfile, and the hash algorithm
+ * @hash_alg. Returns the DER-formatted PKCS#7 signature, with the signed data
+ * included (not detached), in @sig_ret and @sig_size_ret.
+ */
+static bool sign_data(const void *data_to_sign, size_t data_size,
+ const char *keyfile, const char *certfile,
+ const struct fsverity_hash_alg *hash_alg,
+ void **sig_ret, int *sig_size_ret)
+{
+ EVP_PKEY *pkey = NULL;
+ X509 *cert = NULL;
+ const EVP_MD *md;
+ bool ok = false;
+
+ pkey = read_private_key(keyfile);
+ if (!pkey)
+ goto out;
+
+ cert = read_certificate(certfile);
+ if (!cert)
+ goto out;
+
+ OpenSSL_add_all_digests();
+ ASSERT(hash_alg->cryptographic);
+ md = EVP_get_digestbyname(hash_alg->name);
+ if (!md) {
+ fprintf(stderr,
+ "Warning: '%s' algorithm not found in OpenSSL library.\n"
+ " Falling back to SHA-256 signature.\n",
+ hash_alg->name);
+ md = EVP_sha256();
+ }
+
+ ok = sign_pkcs7(data_to_sign, data_size, pkey, cert, md,
+ sig_ret, sig_size_ret);
+out:
+ EVP_PKEY_free(pkey);
+ X509_free(cert);
+ return ok;
+}
+
+/*
+ * Read a file measurement signature in PKCS#7 DER format from @signature_file,
+ * validate that the signed data matches the expected measurement, then return
+ * the PKCS#7 DER message in @sig_ret and @sig_size_ret.
+ */
+static bool read_signature(const char *signature_file,
+ const u8 *expected_measurement,
+ const struct fsverity_hash_alg *hash_alg,
+ void **sig_ret, int *sig_size_ret)
+{
+ struct filedes file = { .fd = -1 };
+ u64 filesize;
+ void *sig = NULL;
+ bool ok = false;
+ const char *reason;
+
+ if (!open_file(&file, signature_file, O_RDONLY, 0))
+ goto out;
+ if (!get_file_size(&file, &filesize))
+ goto out;
+ if (filesize <= 0) {
+ error_msg("signature file '%s' is empty", signature_file);
+ goto out;
+ }
+ if (filesize > 1000000) {
+ error_msg("signature file '%s' is too large", signature_file);
+ goto out;
+ }
+ sig = xmalloc(filesize);
+ if (!full_read(&file, sig, filesize))
+ goto out;
+
+ reason = compare_fsverity_digest_pkcs7(sig, filesize,
+ expected_measurement, hash_alg);
+ if (reason) {
+ error_msg("signed file measurement from '%s' is invalid (%s)",
+ signature_file, reason);
+ goto out;
+ }
+
+ printf("Using existing signed file measurement from '%s'\n",
+ signature_file);
+ *sig_ret = sig;
+ *sig_size_ret = filesize;
+ sig = NULL;
+ ok = true;
+out:
+ filedes_close(&file);
+ free(sig);
+ return ok;
+}
+
+static bool write_signature(const char *signature_file,
+ const void *sig, int sig_size)
+{
+ struct filedes file;
+ bool ok;
+
+ if (!open_file(&file, signature_file, O_WRONLY|O_CREAT|O_TRUNC, 0644))
+ return false;
+ ok = full_write(&file, sig, sig_size);
+ ok &= filedes_close(&file);
+ if (ok)
+ printf("Wrote signed file measurement to '%s'\n",
+ signature_file);
+ return ok;
+}
+
+/*
+ * Append the signed file measurement to the output file as a PKCS7_SIGNATURE
+ * extension item.
+ *
+ * Return: exit status code (0 on success, nonzero on failure)
+ */
+int append_signed_measurement(struct filedes *out,
+ const struct fsveritysetup_params *params,
+ const u8 *measurement)
+{
+ struct fsverity_digest_disk *data_to_sign = NULL;
+ void *sig = NULL;
+ void *extbuf = NULL;
+ void *tmp;
+ int sig_size;
+ int status;
+
+ if (params->signing_key_file) {
+ size_t data_size = sizeof(*data_to_sign) +
+ params->hash_alg->digest_size;
+
+ /* Sign the file measurement using the given key */
+
+ data_to_sign = xzalloc(data_size);
+ data_to_sign->digest_algorithm =
+ cpu_to_le16(params->hash_alg - fsverity_hash_algs);
+ data_to_sign->digest_size =
+ cpu_to_le16(params->hash_alg->digest_size);
+ memcpy(data_to_sign->digest, measurement,
+ params->hash_alg->digest_size);
+
+ ASSERT(compare_fsverity_digest(data_to_sign, data_size,
+ measurement, params->hash_alg) == NULL);
+
+ if (!sign_data(data_to_sign, data_size,
+ params->signing_key_file,
+ params->signing_cert_file ?:
+ params->signing_key_file,
+ params->hash_alg,
+ &sig, &sig_size))
+ goto out_err;
+
+ if (params->signature_file &&
+ !write_signature(params->signature_file, sig, sig_size))
+ goto out_err;
+ } else {
+ /* Using a signature that was already created */
+ if (!read_signature(params->signature_file, measurement,
+ params->hash_alg, &sig, &sig_size))
+ goto out_err;
+ }
+
+ tmp = extbuf = xzalloc(FSVERITY_EXTLEN(sig_size));
+ fsverity_append_extension(&tmp, FS_VERITY_EXT_PKCS7_SIGNATURE,
+ sig, sig_size);
+ ASSERT(tmp == extbuf + FSVERITY_EXTLEN(sig_size));
+ if (!full_write(out, extbuf, FSVERITY_EXTLEN(sig_size)))
+ goto out_err;
+ status = 0;
+out:
+ free(data_to_sign);
+ free(sig);
+ free(extbuf);
+ return status;
+
+out_err:
+ status = 1;
+ goto out;
+}
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..58a2a60
--- /dev/null
+++ b/util.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Utility functions for the 'fsverity' program
+ *
+ * Copyright (C) 2018 Google LLC
+ *
+ * Written by Eric Biggers.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "util.h"
+
+/* ========== Memory allocation ========== */
+
+void *xmalloc(size_t size)
+{
+ void *p = malloc(size);
+
+ if (!p)
+ fatal_error("out of memory");
+ return p;
+}
+
+void *xzalloc(size_t size)
+{
+ return memset(xmalloc(size), 0, size);
+}
+
+void *xmemdup(const void *mem, size_t size)
+{
+ return memcpy(xmalloc(size), mem, size);
+}
+
+char *xstrdup(const char *s)
+{
+ return xmemdup(s, strlen(s) + 1);
+}
+
+char *xasprintf(const char *format, ...)
+{
+ va_list va1, va2;
+ int size;
+ char *s;
+
+ va_start(va1, format);
+
+ va_copy(va2, va1);
+ size = vsnprintf(NULL, 0, format, va2);
+ va_end(va2);
+
+ ASSERT(size >= 0);
+ s = xmalloc(size + 1);
+ vsprintf(s, format, va1);
+
+ va_end(va1);
+ return s;
+}
+
+/* ========== Error messages and assertions ========== */
+
+void do_error_msg(const char *format, va_list va, int err)
+{
+ fputs("ERROR: ", stderr);
+ vfprintf(stderr, format, va);
+ if (err)
+ fprintf(stderr, ": %s", strerror(err));
+ putc('\n', stderr);
+}
+
+void error_msg(const char *format, ...)
+{
+ va_list va;
+
+ va_start(va, format);
+ do_error_msg(format, va, 0);
+ va_end(va);
+}
+
+void error_msg_errno(const char *format, ...)
+{
+ va_list va;
+
+ va_start(va, format);
+ do_error_msg(format, va, errno);
+ va_end(va);
+}
+
+__noreturn void fatal_error(const char *format, ...)
+{
+ va_list va;
+
+ va_start(va, format);
+ do_error_msg(format, va, 0);
+ va_end(va);
+ abort();
+}
+
+__noreturn void assertion_failed(const char *expr, const char *file, int line)
+{
+ fatal_error("Assertion failed: %s at %s:%d", expr, file, line);
+}
+
+/* ========== File utilities ========== */
+
+bool open_file(struct filedes *file, const char *filename, int flags, int mode)
+{
+ file->fd = open(filename, flags, mode);
+ if (file->fd < 0) {
+ error_msg_errno("can't open '%s' for %s", filename,
+ (flags & O_ACCMODE) == O_RDONLY ? "reading" :
+ (flags & O_ACCMODE) == O_WRONLY ? "writing" :
+ "reading and writing");
+ return false;
+ }
+ file->autodelete = false;
+ file->name = xstrdup(filename);
+ file->pos = 0;
+ return true;
+}
+
+bool open_tempfile(struct filedes *file)
+{
+ const char *tmpdir = getenv("TMPDIR") ?: P_tmpdir;
+ char *name = xasprintf("%s/fsverity-XXXXXX", tmpdir);
+
+ file->fd = mkstemp(name);
+ if (file->fd < 0) {
+ error_msg_errno("can't create temporary file");
+ free(name);
+ return false;
+ }
+ file->autodelete = true;
+ file->name = name;
+ file->pos = 0;
+ return true;
+}
+
+bool get_file_size(struct filedes *file, u64 *size_ret)
+{
+ struct stat stbuf;
+
+ if (fstat(file->fd, &stbuf) != 0) {
+ error_msg_errno("can't stat file '%s'", file->name);
+ return false;
+ }
+ *size_ret = stbuf.st_size;
+ return true;
+}
+
+bool filedes_seek(struct filedes *file, u64 pos, int whence)
+{
+ off_t res;
+
+ res = lseek(file->fd, pos, whence);
+ if (res < 0) {
+ error_msg_errno("seek error on '%s'", file->name);
+ return false;
+ }
+ file->pos = res;
+ return true;
+}
+
+bool full_read(struct filedes *file, void *buf, size_t count)
+{
+ while (count) {
+ int n = read(file->fd, buf, min(count, INT_MAX));
+
+ if (n < 0) {
+ error_msg_errno("reading from '%s'", file->name);
+ return false;
+ }
+ if (n == 0) {
+ error_msg("unexpected end-of-file on '%s'", file->name);
+ return false;
+ }
+ buf += n;
+ count -= n;
+ file->pos += n;
+ }
+ return true;
+}
+
+bool full_pread(struct filedes *file, void *buf, size_t count, u64 offset)
+{
+ while (count) {
+ int n = pread(file->fd, buf, min(count, INT_MAX), offset);
+
+ if (n < 0) {
+ error_msg_errno("reading from '%s'", file->name);
+ return false;
+ }
+ if (n == 0) {
+ error_msg("unexpected end-of-file on '%s'", file->name);
+ return false;
+ }
+ buf += n;
+ count -= n;
+ offset += n;
+ }
+ return true;
+}
+
+bool full_write(struct filedes *file, const void *buf, size_t count)
+{
+ while (count) {
+ int n = write(file->fd, buf, min(count, INT_MAX));
+
+ if (n < 0) {
+ error_msg_errno("writing to '%s'", file->name);
+ return false;
+ }
+ buf += n;
+ count -= n;
+ file->pos += n;
+ }
+ return true;
+}
+
+bool full_pwrite(struct filedes *file, const void *buf, size_t count,
+ u64 offset)
+{
+ while (count) {
+ int n = pwrite(file->fd, buf, min(count, INT_MAX), offset);
+
+ if (n < 0) {
+ error_msg_errno("writing to '%s'", file->name);
+ return false;
+ }
+ buf += n;
+ count -= n;
+ offset += n;
+ }
+ return true;
+}
+
+/* Copy 'count' bytes of data from 'src' to 'dst' */
+bool copy_file_data(struct filedes *src, struct filedes *dst, u64 count)
+{
+ char buf[4096];
+
+ while (count) {
+ size_t n = min(count, sizeof(buf));
+
+ if (!full_read(src, buf, n))
+ return false;
+ if (!full_write(dst, buf, n))
+ return false;
+ count -= n;
+ }
+ return true;
+}
+
+/* Write 'count' bytes of zeroes to the file */
+bool write_zeroes(struct filedes *file, u64 count)
+{
+ char buf[4096];
+
+ memset(buf, 0, min(count, sizeof(buf)));
+
+ while (count) {
+ size_t n = min(count, sizeof(buf));
+
+ if (!full_write(file, buf, n))
+ return false;
+ count -= n;
+ }
+ return true;
+}
+
+bool filedes_close(struct filedes *file)
+{
+ int res;
+
+ if (file->fd < 0)
+ return true;
+ res = close(file->fd);
+ if (res != 0)
+ error_msg_errno("closing '%s'", file->name);
+ if (file->autodelete)
+ (void)unlink(file->name);
+ file->fd = -1;
+ free(file->name);
+ file->name = NULL;
+ return res == 0;
+}
+
+/* ========== String utilities ========== */
+
+static int hex2bin_char(char c)
+{
+ if (c >= '0' && c <= '9')
+ return c - '0';
+ if (c >= 'a' && c <= 'f')
+ return 10 + (c - 'a');
+ if (c >= 'A' && c <= 'F')
+ return 10 + (c - 'A');
+ return -1;
+}
+
+bool hex2bin(const char *hex, u8 *bin, size_t bin_len)
+{
+ if (strlen(hex) != 2 * bin_len)
+ return false;
+
+ while (bin_len--) {
+ int hi = hex2bin_char(*hex++);
+ int lo = hex2bin_char(*hex++);
+
+ if (hi < 0 || lo < 0)
+ return false;
+ *bin++ = (hi << 4) | lo;
+ }
+ return true;
+}
+
+static char bin2hex_char(u8 nibble)
+{
+ ASSERT(nibble <= 0xf);
+
+ if (nibble < 10)
+ return '0' + nibble;
+ return 'a' + (nibble - 10);
+}
+
+void bin2hex(const u8 *bin, size_t bin_len, char *hex)
+{
+ while (bin_len--) {
+ *hex++ = bin2hex_char(*bin >> 4);
+ *hex++ = bin2hex_char(*bin & 0xf);
+ bin++;
+ }
+ *hex = '\0';
+}
+
+void string_list_append(struct string_list *list, char *string)
+{
+ ASSERT(list->length <= list->capacity);
+ if (list->length == list->capacity) {
+ list->capacity = (list->capacity * 2) + 4;
+ list->strings = realloc(list->strings,
+ sizeof(list->strings[0]) *
+ list->capacity);
+ if (!list->strings)
+ fatal_error("out of memory");
+ }
+ list->strings[list->length++] = string;
+}
+
+void string_list_destroy(struct string_list *list)
+{
+ free(list->strings);
+ memset(list, 0, sizeof(*list));
+}
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..c4cbe48
--- /dev/null
+++ b/util.h
@@ -0,0 +1,160 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Utility functions and macros for the 'fsverity' program
+ *
+ * Copyright (C) 2018 Google LLC
+ */
+#ifndef UTIL_H
+#define UTIL_H
+
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+#ifndef __force
+# ifdef __CHECKER__
+# define __force __attribute__((force))
+# else
+# define __force
+# endif
+#endif
+
+#ifndef __printf
+# define __printf(fmt_idx, vargs_idx) \
+ __attribute__((format(printf, fmt_idx, vargs_idx)))
+#endif
+
+#ifndef __noreturn
+# define __noreturn __attribute__((noreturn))
+#endif
+
+#ifndef __cold
+# define __cold __attribute__((cold))
+#endif
+
+#define min(a, b) ({ \
+ __typeof__(a) _a = (a); \
+ __typeof__(b) _b = (b); \
+ _a < _b ? _a : _b; \
+})
+#define max(a, b) ({ \
+ __typeof__(a) _a = (a); \
+ __typeof__(b) _b = (b); \
+ _a > _b ? _a : _b; \
+})
+
+#define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0]))
+
+#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+
+/*
+ * Round 'v' up to the next 'alignment'-byte aligned boundary.
+ * 'alignment' must be a power of 2.
+ */
+#define ALIGN(v, alignment) (((v) + ((alignment) - 1)) & ~((alignment) - 1))
+
+static inline bool is_power_of_2(unsigned long n)
+{
+ return n != 0 && ((n & (n - 1)) == 0);
+}
+
+static inline int ilog2(unsigned long n)
+{
+ return (8 * sizeof(n) - 1) - __builtin_clzl(n);
+}
+
+/* ========== Endianness conversion ========== */
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+# define cpu_to_le16(v) ((__force __le16)(u16)(v))
+# define le16_to_cpu(v) ((__force u16)(__le16)(v))
+# define cpu_to_le32(v) ((__force __le32)(u32)(v))
+# define le32_to_cpu(v) ((__force u32)(__le32)(v))
+# define cpu_to_le64(v) ((__force __le64)(u64)(v))
+# define le64_to_cpu(v) ((__force u64)(__le64)(v))
+# define cpu_to_be16(v) ((__force __be16)__builtin_bswap16(v))
+# define be16_to_cpu(v) (__builtin_bswap16((__force u16)(v)))
+# define cpu_to_be32(v) ((__force __be32)__builtin_bswap32(v))
+# define be32_to_cpu(v) (__builtin_bswap32((__force u32)(v)))
+# define cpu_to_be64(v) ((__force __be64)__builtin_bswap64(v))
+# define be64_to_cpu(v) (__builtin_bswap64((__force u64)(v)))
+#else
+# define cpu_to_le16(v) ((__force __le16)__builtin_bswap16(v))
+# define le16_to_cpu(v) (__builtin_bswap16((__force u16)(v)))
+# define cpu_to_le32(v) ((__force __le32)__builtin_bswap32(v))
+# define le32_to_cpu(v) (__builtin_bswap32((__force u32)(v)))
+# define cpu_to_le64(v) ((__force __le64)__builtin_bswap64(v))
+# define le64_to_cpu(v) (__builtin_bswap64((__force u64)(v)))
+# define cpu_to_be16(v) ((__force __be16)(u16)(v))
+# define be16_to_cpu(v) ((__force u16)(__be16)(v))
+# define cpu_to_be32(v) ((__force __be32)(u32)(v))
+# define be32_to_cpu(v) ((__force u32)(__be32)(v))
+# define cpu_to_be64(v) ((__force __be64)(u64)(v))
+# define be64_to_cpu(v) ((__force u64)(__be64)(v))
+#endif
+
+/* ========== Memory allocation ========== */
+
+void *xmalloc(size_t size);
+void *xzalloc(size_t size);
+void *xmemdup(const void *mem, size_t size);
+char *xstrdup(const char *s);
+__printf(1, 2) char *xasprintf(const char *format, ...);
+
+/* ========== Error messages and assertions ========== */
+
+__cold void do_error_msg(const char *format, va_list va, int err);
+__printf(1, 2) __cold void error_msg(const char *format, ...);
+__printf(1, 2) __cold void error_msg_errno(const char *format, ...);
+__printf(1, 2) __cold __noreturn void fatal_error(const char *format, ...);
+__cold __noreturn void assertion_failed(const char *expr,
+ const char *file, int line);
+
+#define ASSERT(e) ({ if (!(e)) assertion_failed(#e, __FILE__, __LINE__); })
+
+/* ========== File utilities ========== */
+
+struct filedes {
+ int fd;
+ bool autodelete; /* unlink when closed? */
+ char *name; /* filename, for logging or error messages */
+ u64 pos; /* lseek() position */
+};
+
+bool open_file(struct filedes *file, const char *filename, int flags, int mode);
+bool open_tempfile(struct filedes *file);
+bool get_file_size(struct filedes *file, u64 *size_ret);
+bool filedes_seek(struct filedes *file, u64 pos, int whence);
+bool full_read(struct filedes *file, void *buf, size_t count);
+bool full_pread(struct filedes *file, void *buf, size_t count, u64 offset);
+bool full_write(struct filedes *file, const void *buf, size_t count);
+bool full_pwrite(struct filedes *file, const void *buf, size_t count,
+ u64 offset);
+bool copy_file_data(struct filedes *src, struct filedes *dst, u64 length);
+bool write_zeroes(struct filedes *file, u64 length);
+bool filedes_close(struct filedes *file);
+
+/* ========== String utilities ========== */
+
+bool hex2bin(const char *hex, u8 *bin, size_t bin_len);
+void bin2hex(const u8 *bin, size_t bin_len, char *hex);
+
+struct string_list {
+ char **strings;
+ size_t length;
+ size_t capacity;
+};
+
+#define STRING_LIST_INITIALIZER { .strings = NULL, .length = 0, .capacity = 0 }
+#define STRING_LIST(_list) struct string_list _list = STRING_LIST_INITIALIZER
+
+void string_list_append(struct string_list *list, char *string);
+void string_list_destroy(struct string_list *list);
+
+#endif /* UTIL_H */
