commit 919deb473d489410067b74dd5576cd3692f223fd Author: moparisthebest Date: Wed Dec 25 01:21:43 2019 -0500 Initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..4585bf0 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +pegh +pegh.exe diff --git a/LICENSE.md b/LICENSE.md new file mode 100644 index 0000000..cba6f6a --- /dev/null +++ b/LICENSE.md @@ -0,0 +1,660 @@ +### GNU AFFERO GENERAL PUBLIC LICENSE + +Version 3, 19 November 2007 + +Copyright (C) 2007 Free Software Foundation, Inc. + + +Everyone is permitted to copy and distribute verbatim copies of this +license document, but changing it is not allowed. + +### Preamble + +The GNU Affero General Public License is a free, copyleft license for +software and other kinds of works, specifically designed to ensure +cooperation with the community in the case of network server software. + +The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +our General Public Licenses are intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains +free software for all its users. + +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 +them 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. + +Developers that use our General Public Licenses protect your rights +with two steps: (1) assert copyright on the software, and (2) offer +you this License which gives you legal permission to copy, distribute +and/or modify the software. + +A secondary benefit of defending all users' freedom is that +improvements made in alternate versions of the program, if they +receive widespread use, become available for other developers to +incorporate. Many developers of free software are heartened and +encouraged by the resulting cooperation. However, in the case of +software used on network servers, this result may fail to come about. +The GNU General Public License permits making a modified version and +letting the public access it on a server without ever releasing its +source code to the public. + +The GNU Affero General Public License is designed specifically to +ensure that, in such cases, the modified source code becomes available +to the community. It requires the operator of a network server to +provide the source code of the modified version running there to the +users of that server. Therefore, public use of a modified version, on +a publicly accessible server, gives the public access to the source +code of the modified version. + +An older license, called the Affero General Public License and +published by Affero, was designed to accomplish similar goals. This is +a different license, not a version of the Affero GPL, but Affero has +released a new version of the Affero GPL which permits relicensing +under this license. + +The precise terms and conditions for copying, distribution and +modification follow. + +### TERMS AND CONDITIONS + +#### 0. Definitions. + +"This License" refers to version 3 of the GNU Affero General Public +License. + +"Copyright" also means copyright-like laws that apply to other kinds +of works, such as semiconductor masks. + +"The Program" refers to any copyrightable work licensed under this +License. Each licensee is addressed as "you". "Licensees" and +"recipients" may be individuals or organizations. + +To "modify" a work means to copy from or adapt all or part of the work +in a fashion requiring copyright permission, other than the making of +an exact copy. The resulting work is called a "modified version" of +the earlier work or a work "based on" the earlier work. + +A "covered work" means either the unmodified Program or a work based +on the Program. + +To "propagate" a work means to do anything with it that, without +permission, would make you directly or secondarily liable for +infringement under applicable copyright law, except executing it on a +computer or modifying a private copy. Propagation includes copying, +distribution (with or without modification), making available to the +public, and in some countries other activities as well. + +To "convey" a work means any kind of propagation that enables other +parties to make or receive copies. Mere interaction with a user +through a computer network, with no transfer of a copy, is not +conveying. + +An interactive user interface displays "Appropriate Legal Notices" to +the extent that it includes a convenient and prominently visible +feature that (1) displays an appropriate copyright notice, and (2) +tells the user that there is no warranty for the work (except to the +extent that warranties are provided), that licensees may convey the +work under this License, and how to view a copy of this License. If +the interface presents a list of user commands or options, such as a +menu, a prominent item in the list meets this criterion. + +#### 1. Source Code. + +The "source code" for a work means the preferred form of the work for +making modifications to it. "Object code" means any non-source form of +a work. + +A "Standard Interface" means an interface that either is an official +standard defined by a recognized standards body, or, in the case of +interfaces specified for a particular programming language, one that +is widely used among developers working in that language. + +The "System Libraries" of an executable work include anything, other +than the work as a whole, that (a) is included in the normal form of +packaging a Major Component, but which is not part of that Major +Component, and (b) serves only to enable use of the work with that +Major Component, or to implement a Standard Interface for which an +implementation is available to the public in source code form. A +"Major Component", in this context, means a major essential component +(kernel, window system, and so on) of the specific operating system +(if any) on which the executable work runs, or a compiler used to +produce the work, or an object code interpreter used to run it. + +The "Corresponding Source" for a work in object code form means all +the source code needed to generate, install, and (for an executable +work) run the object code and to modify the work, including scripts to +control those activities. However, it does not include the work's +System Libraries, or general-purpose tools or generally available free +programs which are used unmodified in performing those activities but +which are not part of the work. For example, Corresponding Source +includes interface definition files associated with source files for +the work, and the source code for shared libraries and dynamically +linked subprograms that the work is specifically designed to require, +such as by intimate data communication or control flow between those +subprograms and other parts of the work. + +The Corresponding Source need not include anything that users can +regenerate automatically from other parts of the Corresponding Source. + +The Corresponding Source for a work in source code form is that same +work. + +#### 2. Basic Permissions. + +All rights granted under this License are granted for the term of +copyright on the Program, and are irrevocable provided the stated +conditions are met. This License explicitly affirms your unlimited +permission to run the unmodified Program. The output from running a +covered work is covered by this License only if the output, given its +content, constitutes a covered work. This License acknowledges your +rights of fair use or other equivalent, as provided by copyright law. + +You may make, run and propagate covered works that you do not convey, +without conditions so long as your license otherwise remains in force. +You may convey covered works to others for the sole purpose of having +them make modifications exclusively for you, or provide you with +facilities for running those works, provided that you comply with the +terms of this License in conveying all material for which you do not +control copyright. Those thus making or running the covered works for +you must do so exclusively on your behalf, under your direction and +control, on terms that prohibit them from making any copies of your +copyrighted material outside their relationship with you. + +Conveying under any other circumstances is permitted solely under the +conditions stated below. Sublicensing is not allowed; section 10 makes +it unnecessary. + +#### 3. Protecting Users' Legal Rights From Anti-Circumvention Law. + +No covered work shall be deemed part of an effective technological +measure under any applicable law fulfilling obligations under article +11 of the WIPO copyright treaty adopted on 20 December 1996, or +similar laws prohibiting or restricting circumvention of such +measures. + +When you convey a covered work, you waive any legal power to forbid +circumvention of technological measures to the extent such +circumvention is effected by exercising rights under this License with +respect to the covered work, and you disclaim any intention to limit +operation or modification of the work as a means of enforcing, against +the work's users, your or third parties' legal rights to forbid +circumvention of technological measures. + +#### 4. Conveying Verbatim Copies. + +You may convey 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; +keep intact all notices stating that this License and any +non-permissive terms added in accord with section 7 apply to the code; +keep intact all notices of the absence of any warranty; and give all +recipients a copy of this License along with the Program. + +You may charge any price or no price for each copy that you convey, +and you may offer support or warranty protection for a fee. + +#### 5. Conveying Modified Source Versions. + +You may convey a work based on the Program, or the modifications to +produce it from the Program, in the form of source code under the +terms of section 4, provided that you also meet all of these +conditions: + +- a) The work must carry prominent notices stating that you modified + it, and giving a relevant date. +- b) The work must carry prominent notices stating that it is + released under this License and any conditions added under + section 7. This requirement modifies the requirement in section 4 + to "keep intact all notices". +- c) You must license the entire work, as a whole, under this + License to anyone who comes into possession of a copy. This + License will therefore apply, along with any applicable section 7 + additional terms, to the whole of the work, and all its parts, + regardless of how they are packaged. This License gives no + permission to license the work in any other way, but it does not + invalidate such permission if you have separately received it. +- d) If the work has interactive user interfaces, each must display + Appropriate Legal Notices; however, if the Program has interactive + interfaces that do not display Appropriate Legal Notices, your + work need not make them do so. + +A compilation of a covered work with other separate and independent +works, which are not by their nature extensions of the covered work, +and which are not combined with it such as to form a larger program, +in or on a volume of a storage or distribution medium, is called an +"aggregate" if the compilation and its resulting copyright are not +used to limit the access or legal rights of the compilation's users +beyond what the individual works permit. Inclusion of a covered work +in an aggregate does not cause this License to apply to the other +parts of the aggregate. + +#### 6. Conveying Non-Source Forms. + +You may convey a covered work in object code form under the terms of +sections 4 and 5, provided that you also convey the machine-readable +Corresponding Source under the terms of this License, in one of these +ways: + +- a) Convey the object code in, or embodied in, a physical product + (including a physical distribution medium), accompanied by the + Corresponding Source fixed on a durable physical medium + customarily used for software interchange. +- b) Convey the object code in, or embodied in, a physical product + (including a physical distribution medium), accompanied by a + written offer, valid for at least three years and valid for as + long as you offer spare parts or customer support for that product + model, to give anyone who possesses the object code either (1) a + copy of the Corresponding Source for all the software in the + product that is covered by this License, on a durable physical + medium customarily used for software interchange, for a price no + more than your reasonable cost of physically performing this + conveying of source, or (2) access to copy the Corresponding + Source from a network server at no charge. +- c) Convey individual copies of the object code with a copy of the + written offer to provide the Corresponding Source. This + alternative is allowed only occasionally and noncommercially, and + only if you received the object code with such an offer, in accord + with subsection 6b. +- d) Convey the object code by offering access from a designated + place (gratis or for a charge), and offer equivalent access to the + Corresponding Source in the same way through the same place at no + further charge. You need not require recipients to copy the + Corresponding Source along with the object code. If the place to + copy the object code is a network server, the Corresponding Source + may be on a different server (operated by you or a third party) + that supports equivalent copying facilities, provided you maintain + clear directions next to the object code saying where to find the + Corresponding Source. Regardless of what server hosts the + Corresponding Source, you remain obligated to ensure that it is + available for as long as needed to satisfy these requirements. +- e) Convey the object code using peer-to-peer transmission, + provided you inform other peers where the object code and + Corresponding Source of the work are being offered to the general + public at no charge under subsection 6d. + +A separable portion of the object code, whose source code is excluded +from the Corresponding Source as a System Library, need not be +included in conveying the object code work. + +A "User Product" is either (1) a "consumer product", which means any +tangible personal property which is normally used for personal, +family, or household purposes, or (2) anything designed or sold for +incorporation into a dwelling. In determining whether a product is a +consumer product, doubtful cases shall be resolved in favor of +coverage. For a particular product received by a particular user, +"normally used" refers to a typical or common use of that class of +product, regardless of the status of the particular user or of the way +in which the particular user actually uses, or expects or is expected +to use, the product. A product is a consumer product regardless of +whether the product has substantial commercial, industrial or +non-consumer uses, unless such uses represent the only significant +mode of use of the product. + +"Installation Information" for a User Product means any methods, +procedures, authorization keys, or other information required to +install and execute modified versions of a covered work in that User +Product from a modified version of its Corresponding Source. The +information must suffice to ensure that the continued functioning of +the modified object code is in no case prevented or interfered with +solely because modification has been made. + +If you convey an object code work under this section in, or with, or +specifically for use in, a User Product, and the conveying occurs as +part of a transaction in which the right of possession and use of the +User Product is transferred to the recipient in perpetuity or for a +fixed term (regardless of how the transaction is characterized), the +Corresponding Source conveyed under this section must be accompanied +by the Installation Information. But this requirement does not apply +if neither you nor any third party retains the ability to install +modified object code on the User Product (for example, the work has +been installed in ROM). + +The requirement to provide Installation Information does not include a +requirement to continue to provide support service, warranty, or +updates for a work that has been modified or installed by the +recipient, or for the User Product in which it has been modified or +installed. Access to a network may be denied when the modification +itself materially and adversely affects the operation of the network +or violates the rules and protocols for communication across the +network. + +Corresponding Source conveyed, and Installation Information provided, +in accord with this section must be in a format that is publicly +documented (and with an implementation available to the public in +source code form), and must require no special password or key for +unpacking, reading or copying. + +#### 7. Additional Terms. + +"Additional permissions" are terms that supplement the terms of this +License by making exceptions from one or more of its conditions. +Additional permissions that are applicable to the entire Program shall +be treated as though they were included in this License, to the extent +that they are valid under applicable law. If additional permissions +apply only to part of the Program, that part may be used separately +under those permissions, but the entire Program remains governed by +this License without regard to the additional permissions. + +When you convey a copy of a covered work, you may at your option +remove any additional permissions from that copy, or from any part of +it. (Additional permissions may be written to require their own +removal in certain cases when you modify the work.) You may place +additional permissions on material, added by you to a covered work, +for which you have or can give appropriate copyright permission. + +Notwithstanding any other provision of this License, for material you +add to a covered work, you may (if authorized by the copyright holders +of that material) supplement the terms of this License with terms: + +- a) Disclaiming warranty or limiting liability differently from the + terms of sections 15 and 16 of this License; or +- b) Requiring preservation of specified reasonable legal notices or + author attributions in that material or in the Appropriate Legal + Notices displayed by works containing it; or +- c) Prohibiting misrepresentation of the origin of that material, + or requiring that modified versions of such material be marked in + reasonable ways as different from the original version; or +- d) Limiting the use for publicity purposes of names of licensors + or authors of the material; or +- e) Declining to grant rights under trademark law for use of some + trade names, trademarks, or service marks; or +- f) Requiring indemnification of licensors and authors of that + material by anyone who conveys the material (or modified versions + of it) with contractual assumptions of liability to the recipient, + for any liability that these contractual assumptions directly + impose on those licensors and authors. + +All other non-permissive additional terms are considered "further +restrictions" within the meaning of section 10. If the Program as you +received it, or any part of it, contains a notice stating that it is +governed by this License along with a term that is a further +restriction, you may remove that term. If a license document contains +a further restriction but permits relicensing or conveying under this +License, you may add to a covered work material governed by the terms +of that license document, provided that the further restriction does +not survive such relicensing or conveying. + +If you add terms to a covered work in accord with this section, you +must place, in the relevant source files, a statement of the +additional terms that apply to those files, or a notice indicating +where to find the applicable terms. + +Additional terms, permissive or non-permissive, may be stated in the +form of a separately written license, or stated as exceptions; the +above requirements apply either way. + +#### 8. Termination. + +You may not propagate or modify a covered work except as expressly +provided under this License. Any attempt otherwise to propagate or +modify it is void, and will automatically terminate your rights under +this License (including any patent licenses granted under the third +paragraph of section 11). + +However, if you cease all violation of this License, then your license +from a particular copyright holder is reinstated (a) provisionally, +unless and until the copyright holder explicitly and finally +terminates your license, and (b) permanently, if the copyright holder +fails to notify you of the violation by some reasonable means prior to +60 days after the cessation. + +Moreover, your license from a particular copyright holder is +reinstated permanently if the copyright holder notifies you of the +violation by some reasonable means, this is the first time you have +received notice of violation of this License (for any work) from that +copyright holder, and you cure the violation prior to 30 days after +your receipt of the notice. + +Termination of your rights under this section does not terminate the +licenses of parties who have received copies or rights from you under +this License. If your rights have been terminated and not permanently +reinstated, you do not qualify to receive new licenses for the same +material under section 10. + +#### 9. Acceptance Not Required for Having Copies. + +You are not required to accept this License in order to receive or run +a copy of the Program. Ancillary propagation of a covered work +occurring solely as a consequence of using peer-to-peer transmission +to receive a copy likewise does not require acceptance. However, +nothing other than this License grants you permission to propagate or +modify any covered work. These actions infringe copyright if you do +not accept this License. Therefore, by modifying or propagating a +covered work, you indicate your acceptance of this License to do so. + +#### 10. Automatic Licensing of Downstream Recipients. + +Each time you convey a covered work, the recipient automatically +receives a license from the original licensors, to run, modify and +propagate that work, subject to this License. You are not responsible +for enforcing compliance by third parties with this License. + +An "entity transaction" is a transaction transferring control of an +organization, or substantially all assets of one, or subdividing an +organization, or merging organizations. If propagation of a covered +work results from an entity transaction, each party to that +transaction who receives a copy of the work also receives whatever +licenses to the work the party's predecessor in interest had or could +give under the previous paragraph, plus a right to possession of the +Corresponding Source of the work from the predecessor in interest, if +the predecessor has it or can get it with reasonable efforts. + +You may not impose any further restrictions on the exercise of the +rights granted or affirmed under this License. For example, you may +not impose a license fee, royalty, or other charge for exercise of +rights granted under this License, and you may not initiate litigation +(including a cross-claim or counterclaim in a lawsuit) alleging that +any patent claim is infringed by making, using, selling, offering for +sale, or importing the Program or any portion of it. + +#### 11. Patents. + +A "contributor" is a copyright holder who authorizes use under this +License of the Program or a work on which the Program is based. The +work thus licensed is called the contributor's "contributor version". + +A contributor's "essential patent claims" are all patent claims owned +or controlled by the contributor, whether already acquired or +hereafter acquired, that would be infringed by some manner, permitted +by this License, of making, using, or selling its contributor version, +but do not include claims that would be infringed only as a +consequence of further modification of the contributor version. For +purposes of this definition, "control" includes the right to grant +patent sublicenses in a manner consistent with the requirements of +this License. + +Each contributor grants you a non-exclusive, worldwide, royalty-free +patent license under the contributor's essential patent claims, to +make, use, sell, offer for sale, import and otherwise run, modify and +propagate the contents of its contributor version. + +In the following three paragraphs, a "patent license" is any express +agreement or commitment, however denominated, not to enforce a patent +(such as an express permission to practice a patent or covenant not to +sue for patent infringement). To "grant" such a patent license to a +party means to make such an agreement or commitment not to enforce a +patent against the party. + +If you convey a covered work, knowingly relying on a patent license, +and the Corresponding Source of the work is not available for anyone +to copy, free of charge and under the terms of this License, through a +publicly available network server or other readily accessible means, +then you must either (1) cause the Corresponding Source to be so +available, or (2) arrange to deprive yourself of the benefit of the +patent license for this particular work, or (3) arrange, in a manner +consistent with the requirements of this License, to extend the patent +license to downstream recipients. "Knowingly relying" means you have +actual knowledge that, but for the patent license, your conveying the +covered work in a country, or your recipient's use of the covered work +in a country, would infringe one or more identifiable patents in that +country that you have reason to believe are valid. + +If, pursuant to or in connection with a single transaction or +arrangement, you convey, or propagate by procuring conveyance of, a +covered work, and grant a patent license to some of the parties +receiving the covered work authorizing them to use, propagate, modify +or convey a specific copy of the covered work, then the patent license +you grant is automatically extended to all recipients of the covered +work and works based on it. + +A patent license is "discriminatory" if it does not include within the +scope of its coverage, prohibits the exercise of, or is conditioned on +the non-exercise of one or more of the rights that are specifically +granted under this License. You may not convey a covered work if you +are a party to an arrangement with a third party that is in the +business of distributing software, under which you make payment to the +third party based on the extent of your activity of conveying the +work, and under which the third party grants, to any of the parties +who would receive the covered work from you, a discriminatory patent +license (a) in connection with copies of the covered work conveyed by +you (or copies made from those copies), or (b) primarily for and in +connection with specific products or compilations that contain the +covered work, unless you entered into that arrangement, or that patent +license was granted, prior to 28 March 2007. + +Nothing in this License shall be construed as excluding or limiting +any implied license or other defenses to infringement that may +otherwise be available to you under applicable patent law. + +#### 12. No Surrender of Others' Freedom. + +If 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 convey a +covered work so as to satisfy simultaneously your obligations under +this License and any other pertinent obligations, then as a +consequence you may not convey it at all. For example, if you agree to +terms that obligate you to collect a royalty for further conveying +from those to whom you convey the Program, the only way you could +satisfy both those terms and this License would be to refrain entirely +from conveying the Program. + +#### 13. Remote Network Interaction; Use with the GNU General Public License. + +Notwithstanding any other provision of this License, if you modify the +Program, your modified version must prominently offer all users +interacting with it remotely through a computer network (if your +version supports such interaction) an opportunity to receive the +Corresponding Source of your version by providing access to the +Corresponding Source from a network server at no charge, through some +standard or customary means of facilitating copying of software. This +Corresponding Source shall include the Corresponding Source for any +work covered by version 3 of the GNU General Public License that is +incorporated pursuant to the following paragraph. + +Notwithstanding any other provision of this License, you have +permission to link or combine any covered work with a work licensed +under version 3 of the GNU General Public License into a single +combined work, and to convey the resulting work. The terms of this +License will continue to apply to the part which is the covered work, +but the work with which it is combined will remain governed by version +3 of the GNU General Public License. + +#### 14. Revised Versions of this License. + +The Free Software Foundation may publish revised and/or new versions +of the GNU Affero 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 that a certain numbered version of the GNU Affero General +Public License "or any later version" applies to it, you have the +option of following the terms and conditions either of that numbered +version or of any later version published by the Free Software +Foundation. If the Program does not specify a version number of the +GNU Affero General Public License, you may choose any version ever +published by the Free Software Foundation. + +If the Program specifies that a proxy can decide which future versions +of the GNU Affero General Public License can be used, that proxy's +public statement of acceptance of a version permanently authorizes you +to choose that version for the Program. + +Later license versions may give you additional or different +permissions. However, no additional obligations are imposed on any +author or copyright holder as a result of your choosing to follow a +later version. + +#### 15. Disclaimer of Warranty. + +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. + +#### 16. Limitation of Liability. + +IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR +CONVEYS 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. + +#### 17. Interpretation of Sections 15 and 16. + +If the disclaimer of warranty and limitation of liability provided +above cannot be given local legal effect according to their terms, +reviewing courts shall apply local law that most closely approximates +an absolute waiver of all civil liability in connection with the +Program, unless a warranty or assumption of liability accompanies a +copy of the Program in return for a fee. + +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 state +the exclusion of warranty; and each file should have at least the +"copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU Affero General Public License as + published by the Free Software Foundation, either version 3 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 Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License + along with this program. If not, see . + +Also add information on how to contact you by electronic and paper +mail. + +If your software can interact with users remotely through a computer +network, you should also make sure that it provides a way for users to +get its source. For example, if your program is a web application, its +interface could display a "Source" link that leads users to an archive +of the code. There are many ways you could offer source, and different +solutions will be better for different programs; see section 13 for +the specific requirements. + +You should also get your employer (if you work as a programmer) or +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. For more information on this, and how to apply and follow +the GNU AGPL, see . diff --git a/README.md b/README.md new file mode 100644 index 0000000..0082019 --- /dev/null +++ b/README.md @@ -0,0 +1,10 @@ +pegh +---- + +[pegh](http://klingonska.org/dict/?q=tlh%3Apegh) is Klingon for secret + +pegh is a file encryption tool using passwords and authenticated encryption. It returns proper exit codes so you can tell whether encryption/decryption failed or not. + +pegh implements a simple versioned file format so encryption parameters can change in the future, but currently version 0 derives a 256-bit key from your password with scrypt, and uses that to encrypt/decrypt your file with aes-256-gcm. + +todo: document usage and file format \ No newline at end of file diff --git a/pegh.c b/pegh.c new file mode 100644 index 0000000..5961f8d --- /dev/null +++ b/pegh.c @@ -0,0 +1,329 @@ + +/* + * pegh is a file encryption tool using passwords and authenticated encryption + * Copyright (C) 2019 Travis Burtrum + + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 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 Affero General Public License for more details. + + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see . + */ + +// compile with: gcc pegh.c -lcrypto -O3 -o pegh + +#include +#include +#include +#include + +#include +#include +#include + +/* + * tweak scrypt hardness params here + * + * https://tools.ietf.org/html/rfc7914#section-2 + * https://blog.filippo.io/the-scrypt-parameters/ + */ +#define SCRYPT_N 32768 +#define SCRYPT_R 8 +#define SCRYPT_P 1 +#define SCRYPT_MAX_MEM (1024 * 1024 * 64) // 64mb, must be sufficient for N + +// tweak initial read buffer size/reads here +#define BYTES_PER_READ (1024 * 32) // 32kb +#define INITIAL_BUFFER_SIZE (1024 * 256) // 256kb, must be at least 2*BYTES_PER_READ + +// don't touch below here unless you know what you are doing + +#define KEY_LEN 32 // 256 bit key required for AES-256 + +// 1 for file format version, 4 for N, 1 for r, 1 for p +#define PRE_SALT_LEN 7 +// from libsodium's crypto_pwhash_scryptsalsa208sha256_SALTBYTES +#define SALT_LEN 32 +// AES-GCM should only ever have an IV_LEN of 12 +#define IV_LEN 12 +#define GCM_TAG_LEN 16 + +#define SALT_IV_LEN (SALT_LEN+IV_LEN) + +#define OVERHEAD_LEN (PRE_SALT_LEN+SALT_IV_LEN+GCM_TAG_LEN) + +/* + * returns 1 on success, 0 on failure + * + * these will be read from: + * plaintext + * plaintext_len + * key must be length KEY_LEN + * iv must be length IV_LEN + * + * these will be written into: + * ciphertext must have the capacity of at least plaintext_len + * tag must have the capacity of at least GCM_TAG_LEN + */ +int gcm_encrypt(unsigned char *plaintext, size_t plaintext_len, + unsigned char *key, + unsigned char *iv, + unsigned char *ciphertext, + unsigned char *tag) +{ + EVP_CIPHER_CTX *ctx; + int len, ret = 0; + + do { + /* Create and initialise the context */ + if(!(ctx = EVP_CIPHER_CTX_new())) + break; + + /* Initialise the encryption operation. */ + if(1 != EVP_EncryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL)) + break; + + /* Setting IV length is not necessary because the default of 12 bytes (96 bits) will be used + if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, IV_LEN, NULL)) + break; + */ + + /* Initialise key and IV */ + if(1 != EVP_EncryptInit_ex(ctx, NULL, NULL, key, iv)) + break; + + /* + * Provide the message to be encrypted, and obtain the encrypted output. + * EVP_EncryptUpdate can be called multiple times if necessary + */ + if(1 != EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len)) + break; + + /* + * Finalise the encryption. Normally ciphertext bytes may be written at + * this stage, but this does not occur in GCM mode + */ + if(1 != EVP_EncryptFinal_ex(ctx, ciphertext + len, &len)) + break; + + /* Get the tag */ + ret = EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_GET_TAG, GCM_TAG_LEN, tag); + } while(0); + + /* Clean up */ + if(ctx) + EVP_CIPHER_CTX_free(ctx); + + return ret; +} + +/* + * returns 1 on success, 0 on failure + * + * these will be read from: + * ciphertext + * ciphertext_len + * key must be length KEY_LEN + * iv must be length IV_LEN + * tag must be length GCM_TAG_LEN + * + * these will be written into: + * plaintext must have the capacity of at least ciphertext_len + */ +int gcm_decrypt(unsigned char *ciphertext, size_t ciphertext_len, + unsigned char *key, + unsigned char *iv, + unsigned char *tag, + unsigned char *plaintext) +{ + EVP_CIPHER_CTX *ctx; + int len, ret = 0; + + do { + /* Create and initialise the context */ + if(!(ctx = EVP_CIPHER_CTX_new())) + break; + + /* Initialise the decryption operation. */ + if(!EVP_DecryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL)) + break; + + /* Setting IV length is not necessary because the default of 12 bytes (96 bits) will be used + if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_IVLEN, IV_LEN, NULL)) + break; + */ + + /* Initialise key and IV */ + if(!EVP_DecryptInit_ex(ctx, NULL, NULL, key, iv)) + break; + + /* + * Provide the message to be decrypted, and obtain the plaintext output. + * EVP_DecryptUpdate can be called multiple times if necessary + */ + if(!EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len)) + break; + + /* Set expected tag value. Works in OpenSSL 1.0.1d and later */ + if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, GCM_TAG_LEN, tag)) + break; + + /* + * Finalise the decryption. A return value of 1 indicates success, + * return value of 0 is a failure - the plaintext is not trustworthy. + */ + ret = EVP_DecryptFinal_ex(ctx, plaintext + len, &len); + } while(0); + + /* Clean up */ + if(ctx) + EVP_CIPHER_CTX_free(ctx); + + return ret; +} + +/* returns 0 on success, 1 on openssl failure, 2 on other failure */ +int main(int argc, char **argv) +{ + unsigned char key[KEY_LEN] = {0}; + /* these are actually mallocd and freed */ + unsigned char *in_buffer, *out_buffer; + /* these are simply pointers into the above */ + unsigned char *salt, *iv, *ciphertext, *plaintext, *tag; + int exit_code = 2, decrypt = 1; + size_t read, in_buffer_len = 0, out_buffer_len, in_buffer_allocd_size = INITIAL_BUFFER_SIZE; + + uint32_t N = SCRYPT_N; + uint8_t r = SCRYPT_R, p = SCRYPT_P; + + if (argc < 2) { + fprintf(stderr, "Usage: %s [enc]\n", argv[0]); + return exit_code; + } + + // this means we want to encrypt, not decrypt + if (argc > 2 && strcmp("enc", argv[2]) == 0) + decrypt = 0; + + in_buffer = malloc(in_buffer_allocd_size); + if(!in_buffer) { + fprintf(stderr, "in_buffer memory allocation failed\n"); + return exit_code; + } + + while ((read = fread(in_buffer + in_buffer_len, 1, BYTES_PER_READ, stdin)) > 0) { + in_buffer_len += read; + if ((in_buffer_len + BYTES_PER_READ) > in_buffer_allocd_size) { + in_buffer_allocd_size = in_buffer_allocd_size * 1.5; + in_buffer = realloc(in_buffer, in_buffer_allocd_size); + if(!in_buffer) { + fprintf(stderr, "in_buffer memory reallocation failed\n"); + return exit_code; + } + } + } + + do { + if (in_buffer_len <= (decrypt ? OVERHEAD_LEN : 0)) { + fprintf(stderr, "File too small for %scryption\n", decrypt ? "de" : "en"); + break; + } + + out_buffer_len = decrypt ? (in_buffer_len - OVERHEAD_LEN) : (in_buffer_len + OVERHEAD_LEN); + out_buffer = malloc(out_buffer_len); + if(!out_buffer) { + fprintf(stderr, "out_buffer memory allocation failed\n"); + break; + } + + if(decrypt) { + if(in_buffer[0] != 0) { + fprintf(stderr, "unsupported file format version %d, we only support version 0\n", in_buffer[0]); + break; + } + N = ((in_buffer[1] & 0xFF) << 24) + | ((in_buffer[2] & 0xFF) << 16) + | ((in_buffer[3] & 0xFF) << 8) + | (in_buffer[4] & 0xFF); + r = in_buffer[5]; + p = in_buffer[6]; + salt = in_buffer + PRE_SALT_LEN; + iv = salt + SALT_LEN; + ciphertext = iv + IV_LEN; + tag = ciphertext + out_buffer_len; + plaintext = out_buffer; + } else { + out_buffer[0] = 0; + out_buffer[1] = (N >> 24) & 0xFF; + out_buffer[2] = (N >> 16) & 0xFF; + out_buffer[3] = (N >> 8) & 0xFF; + out_buffer[4] = N & 0xFF; + out_buffer[5] = r; + out_buffer[6] = p; + salt = out_buffer + PRE_SALT_LEN; + // generate random salt + if (RAND_bytes(salt, SALT_IV_LEN) <= 0) { + fprintf(stderr, "random salt+iv generation error\n"); + exit_code = 1; + break; + } + iv = salt + SALT_LEN; + ciphertext = iv + IV_LEN; + tag = ciphertext + in_buffer_len; + plaintext = in_buffer; + } + + /* https://commondatastorage.googleapis.com/chromium-boringssl-docs/evp.h.html#EVP_PBE_scrypt */ + if (EVP_PBE_scrypt( + argv[1], strlen(argv[1]), + salt, SALT_LEN, + (uint64_t) N, (uint64_t) r, (uint64_t) p, + SCRYPT_MAX_MEM, + key, KEY_LEN + ) <= 0) { + fprintf(stderr, "scrypt key derivation error\n"); + exit_code = 1; + break; + } + + if(decrypt) { + if (1 != gcm_decrypt(ciphertext, out_buffer_len, + key, iv, + tag, + plaintext)) { + fprintf(stderr, "integrity check failed\n"); + exit_code = 1; + break; + } + } else { + if (1 != gcm_encrypt(plaintext, in_buffer_len, + key, iv, + ciphertext, tag)) { + fprintf(stderr, "encryption failed\n"); + exit_code = 1; + break; + } + } + // success! + fwrite(out_buffer, 1, out_buffer_len, stdout); + exit_code = 0; + } while(0); + + if(in_buffer) + free(in_buffer); + if(out_buffer) + free(out_buffer); + + /* print openssl errors */ + if(exit_code == 1) + ERR_print_errors_fp(stderr); + + return exit_code; +} diff --git a/test.sh b/test.sh new file mode 100755 index 0000000..28f8e7e --- /dev/null +++ b/test.sh @@ -0,0 +1,20 @@ +#!/bin/bash +set -euo pipefail +# try different size files to encrypt/decrypt +[ -e /dev/shm/randombytes ] || dd if=/dev/urandom bs=1M count=100 of=/dev/shm/randombytes + +# compile C and rust code this way +gcc pegh.c -lcrypto -O3 -o pegh +#cargo build --release + +export key=$(openssl rand -base64 20) + +echo "key: $key" + +test () { + bin=$1 + tee >(md5sum 1>&2) < /dev/shm/randombytes | $bin $key enc | $bin $key | md5sum 1>&2 + #$bin $key enc < /dev/shm/randombytes | $bin $key &>/dev/null +} + +time test ./pegh