diff options
-rw-r--r-- | GPL-3 | 674 | ||||
-rw-r--r-- | Makefile | 39 | ||||
-rw-r--r-- | rfc4251.h | 254 | ||||
-rw-r--r-- | ssh-agent-filter.C | 378 | ||||
-rw-r--r-- | ssh-agent.h | 55 |
5 files changed, 1400 insertions, 0 deletions
@@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/> + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is 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. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. 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 +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. + + To protect your rights, we need to prevent others from denying you +these rights or asking you to surrender the rights. Therefore, you have +certain responsibilities if you distribute copies of the software, or if +you modify it: responsibilities to respect the freedom of others. + + For example, if you distribute copies of such a program, whether +gratis or for a fee, you must pass on to the recipients the same +freedoms that you received. 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. + + Developers that use the GNU GPL protect your rights with two steps: +(1) assert copyright on the software, and (2) offer you this License +giving you legal permission to copy, distribute and/or modify it. + + For the developers' and authors' protection, the GPL clearly explains +that there is no warranty for this free software. For both users' and +authors' sake, the GPL requires that modified versions be marked as +changed, so that their problems will not be attributed erroneously to +authors of previous versions. + + Some devices are designed to deny users access to install or run +modified versions of the software inside them, although the manufacturer +can do so. This is fundamentally incompatible with the aim of +protecting users' freedom to change the software. The systematic +pattern of such abuse occurs in the area of products for individuals to +use, which is precisely where it is most unacceptable. Therefore, we +have designed this version of the GPL to prohibit the practice for those +products. If such problems arise substantially in other domains, we +stand ready to extend this provision to those domains in future versions +of the GPL, as needed to protect the freedom of users. + + Finally, every program is threatened constantly by software patents. +States should not allow patents to restrict development and use of +software on general-purpose computers, but in those that do, we wish to +avoid the special danger that patents applied to a free program could +make it effectively proprietary. To prevent this, the GPL assures that +patents cannot be used to render the program non-free. + + 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 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. Use with the GNU Affero General Public License. + + 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 Affero 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 special requirements of the GNU Affero General Public License, +section 13, concerning interaction through a network will apply to the +combination as such. + + 14. Revised Versions of this License. + + The Free Software Foundation may publish revised and/or new versions of +the GNU 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 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 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 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. + + <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 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + <program> Copyright (C) <year> <name of author> + This program 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, your program's commands +might be different; for a GUI interface, you would use an "about box". + + 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 GPL, see +<http://www.gnu.org/licenses/>. + + The GNU 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. But first, please read +<http://www.gnu.org/philosophy/why-not-lgpl.html>. diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..368c4dc --- /dev/null +++ b/Makefile @@ -0,0 +1,39 @@ +# Copyright (C) 2013 Timo Weingärtner <timo@tiwe.de> +# +# This file is part of ssh-agent-filter. +# +# ssh-agent-filter 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 3 of the License, or +# (at your option) any later version. +# +# ssh-agent-filter 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 ssh-agent-filter. If not, see <http://www.gnu.org/licenses/>. + + +CXXFLAGS ?= -g -O2 -Wall -Wold-style-cast + +CXXFLAGS += -std=c++11 +LDFLAGS += -lboost_program_options -lboost_filesystem -lboost_system -lnettle + +all: ssh-agent-filter.1 + +ssh-agent-filter.1: ssh-agent-filter + help2man -n $< -o $@ -N ./$< + +ssh-agent-filter: ssh-agent-filter.o + +ssh-agent-filter.o: ssh-agent-filter.C rfc4251.h ssh-agent.h version.h + +version.h: + test ! -d .git || git describe | sed 's/^.*$$/#define SSH_AGENT_FILTER_VERSION "ssh-agent-filter \0"/' > $@ + +clean: + $(RM) ssh-agent-filter.1 ssh-agent-filter *.o + +.PHONY: version.h diff --git a/rfc4251.h b/rfc4251.h new file mode 100644 index 0000000..0a0a4ad --- /dev/null +++ b/rfc4251.h @@ -0,0 +1,254 @@ +/* + * rfc4251.h -- implements types from RFC 4251, section 5 + * + * rfc4251byte byte + * rfc4251bool bool + * rfc4251uint32 uint32 + * rfc4251uint64 uint64 + * rfc4251string string, incl. mpint and (without splitting) name-list + * + * those structs contain the objects in their RFC 4251 representation, + * conversions are provided via constructors and cast operators + * + * Copyright (C) 2013 Timo Weingärtner <timo@tiwe.de> + * + * This file is part of ssh-agent-filter. + * + * ssh-agent-filter 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 3 of the License, or + * (at your option) any later version. + * + * ssh-agent-filter 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 ssh-agent-filter. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <vector> +#include <string> +#include <iostream> +#include <arpa/inet.h> // ntohl() / htonl() +#include <gmpxx.h> + +struct rfc4251byte { + union { + uint8_t value; + char buf[1]; + }; + + rfc4251byte () = default; + rfc4251byte (rfc4251byte const &) = default; + rfc4251byte (rfc4251byte &&) = default; + + inline explicit rfc4251byte (uint8_t v) : value(v) {} + + rfc4251byte & operator= (rfc4251byte const &) = default; + rfc4251byte & operator= (rfc4251byte &&) = default; + + inline operator uint8_t () const { return value; } +}; + +inline std::istream & operator>> (std::istream & is, rfc4251byte & x) { + return is.read(x.buf, sizeof(x.buf)); +} + +inline std::ostream & operator<< (std::ostream & os, rfc4251byte const & x) { + return os.write(x.buf, sizeof(x.buf));; +} + + +struct rfc4251bool { + union { + bool value; + char buf[1]; + }; + + rfc4251bool () = default; + rfc4251bool (rfc4251bool const &) = default; + rfc4251bool (rfc4251bool &&) = default; + + inline explicit rfc4251bool (uint8_t v) : value(v) {} + + rfc4251bool & operator= (rfc4251bool const &) = default; + rfc4251bool & operator= (rfc4251bool &&) = default; + + inline operator uint8_t () const { return value; } +}; + +inline std::istream & operator>> (std::istream & is, rfc4251bool & x) { + return is.read(x.buf, sizeof(x.buf)); +} + +inline std::ostream & operator<< (std::ostream & os, rfc4251bool const & x) { + return os.write(x.buf, sizeof(x.buf));; +} + + +struct rfc4251uint32 { + union { + uint32_t value; + char buf[4]; + }; + + rfc4251uint32 () = default; + rfc4251uint32 (rfc4251uint32 const &) = default; + rfc4251uint32 (rfc4251uint32 &&) = default; + + inline explicit rfc4251uint32 (uint32_t v) { value = htonl(v); } + + rfc4251uint32 & operator= (rfc4251uint32 const &) = default; + rfc4251uint32 & operator= (rfc4251uint32 &&) = default; + + inline operator uint32_t () const { return ntohl(value); } +}; + +inline std::istream & operator>> (std::istream & is, rfc4251uint32 & x) { + return is.read(x.buf, sizeof(x.buf)); +} + +inline std::ostream & operator<< (std::ostream & os, rfc4251uint32 const & x) { + return os.write(x.buf, sizeof(x.buf));; +} + + +struct rfc4251uint64 { + union { + uint64_t value; + char buf[8]; + }; + + rfc4251uint64 () = default; + rfc4251uint64 (rfc4251uint64 const &) = default; + rfc4251uint64 (rfc4251uint64 &&) = default; + + inline explicit rfc4251uint64 (uint64_t v); + + rfc4251uint64 & operator= (rfc4251uint64 const &) = default; + rfc4251uint64 & operator= (rfc4251uint64 &&) = default; + + inline explicit operator uint64_t () const; +}; + +inline rfc4251uint64::rfc4251uint64 (uint64_t v) { + for (int_fast8_t i = 7; i >= 0; --i) { + buf[i] = v & 0xff; + v >>= 8; + } +} + +inline rfc4251uint64::operator uint64_t () const { + uint64_t ret{0}; + for (uint_fast8_t i = 0; i < 8; ++i) { + ret |= buf[i]; + ret <<= 8; + } + return ret; +} + +inline std::istream & operator>> (std::istream & is, rfc4251uint64 & x) { + return is.read(x.buf, sizeof(x.buf)); +} + +inline std::ostream & operator<< (std::ostream & os, rfc4251uint64 const & x) { + return os.write(x.buf, sizeof(x.buf));; +} + + +struct rfc4251string { + std::vector<char> value; + + rfc4251string () = default; + rfc4251string (rfc4251string const &) = default; + rfc4251string (rfc4251string &&) = default; + + inline explicit rfc4251string (char const *); + inline explicit rfc4251string (char const *, size_t); + inline explicit rfc4251string (std::string const & s) : rfc4251string{s.data(), s.size()} {} + inline explicit rfc4251string (mpz_srcptr); + inline explicit rfc4251string (mpz_class const & x) : rfc4251string{x.get_mpz_t()} {} + + rfc4251string & operator= (rfc4251string const &) = default; + rfc4251string & operator= (rfc4251string &&) = default; + + inline operator std::string () const; + inline operator mpz_class () const; +}; + +inline rfc4251string::rfc4251string (char const * s) { + auto len = ntohl(*reinterpret_cast<uint32_t const *>(s)); + value.insert(value.begin(), s, s + 4 + len); +} + +inline rfc4251string::rfc4251string (char const * s, size_t l) { + rfc4251uint32 tmp(l); + value.insert(value.end(), std::begin(tmp.buf), std::end(tmp.buf)); + value.insert(value.end(), s, s + l); +} + +inline rfc4251string::rfc4251string (mpz_srcptr x) { + if (mpz_sgn(x) == 0) + value.assign(4, 0); + else if (mpz_sgn(x) == 1) { + ssize_t bits = mpz_sizeinbase(x, 2); + ssize_t bytes = (bits + 7) / 8; + ssize_t extrabyte = bits % 8 ? 0 : 1; // need extra byte if MSB is 1 to keep it non-negative + value.resize(4 + bytes + extrabyte); + *reinterpret_cast<uint32_t *>(value.data()) = htonl(bytes + extrabyte); + value[4] = 0; + mpz_export(value.data() + 4 + extrabyte, nullptr, 1, 1, 1, 0, x); + } else { + mpz_class tmp(x); + tmp += 1; + x = tmp.get_mpz_t(); + ssize_t bits = mpz_sizeinbase(x, 2); + ssize_t bytes = (bits + 7) / 8; + ssize_t extrabyte = bits % 8 ? 0 : 1; // need extra byte if MSB is 1 (0 after ^= below) to keep it negative + value.resize(4 + bytes + extrabyte); + *reinterpret_cast<uint32_t *>(value.data()) = htonl(bytes + extrabyte); + value[4] = 0; + mpz_export(value.data() + 4 + extrabyte, nullptr, 1, 1, 1, 0, x); + for (auto i = value.data() + 4; i < value.data() + value.size(); ++i) + *i ^= 0xff; + } +} + +inline rfc4251string::operator std::string () const { + return std::string(value.begin() + 4, value.end()); +} + +inline rfc4251string::operator mpz_class () const { + mpz_class ret; + mpz_import(ret.get_mpz_t(), value.size() - 4, 1, 1, 1, 0, value.data() + 4); + if (mpz_sizeinbase(ret.get_mpz_t(), 2) == (value.size() - 4) * 8) { // negative + mpz_com(ret.get_mpz_t(), ret.get_mpz_t()); + ret += 1; + mpz_neg(ret.get_mpz_t(), ret.get_mpz_t()); + } + return ret; +} + +inline std::istream & operator>> (std::istream & is, rfc4251string & s) { + s.value.resize(4); + if (is.read(s.value.data(), 4)) { + auto len = ntohl(*reinterpret_cast<uint32_t const *>(s.value.data())); + s.value.resize(4 + len); + is.read(s.value.data() + 4, len); + } + return is; +} + +inline std::ostream & operator<< (std::ostream & os, rfc4251string const & s) { + return os.write(s.value.data(), s.value.size()); +} + +inline bool operator== (rfc4251string const & l, rfc4251string const & r) { + return l.value == r.value; +} + +inline bool operator< (rfc4251string const & l, rfc4251string const & r) { + return l.value < r.value; +} diff --git a/ssh-agent-filter.C b/ssh-agent-filter.C new file mode 100644 index 0000000..5aa086b --- /dev/null +++ b/ssh-agent-filter.C @@ -0,0 +1,378 @@ +/* + * ssh-agent-filter.C -- filtering proxy for ssh-agent meant to be forwarded to untrusted servers + * + * Copyright (C) 2013 Timo Weingärtner <timo@tiwe.de> + * + * This file is part of ssh-agent-filter. + * + * ssh-agent-filter 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 3 of the License, or + * (at your option) any later version. + * + * ssh-agent-filter 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 ssh-agent-filter. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <boost/program_options.hpp> +namespace po = boost::program_options; + +#include <boost/filesystem.hpp> +namespace fs = boost::filesystem; + +#include <string> +#include <vector> +#include <set> +#include <iostream> +#include <sstream> +#include <stdexcept> +#include <thread> +#include <ext/stdio_filebuf.h> + +#include <csignal> +#include <cstdlib> +#include <fcntl.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <sysexits.h> +#include <nettle/md5.h> +#include <nettle/base64.h> +#include <nettle/base16.h> + +#include "rfc4251.h" +#include "ssh-agent.h" +#include "version.h" + + +std::vector<std::string> allowed_b64; +std::vector<std::string> allowed_md5; +std::vector<std::string> allowed_comment; +std::set<rfc4251string> allowed_pubkeys; +bool debug{false}; +fs::path path; + + +std::string md5_hex (std::string const & s) { + struct md5_ctx ctx; + md5_init(&ctx); + md5_update(&ctx, s.size(), reinterpret_cast<uint8_t const *>(s.data())); + uint8_t bin[MD5_DIGEST_SIZE]; + md5_digest(&ctx, MD5_DIGEST_SIZE, bin); + uint8_t hex[BASE16_ENCODE_LENGTH(MD5_DIGEST_SIZE)]; + base16_encode_update(hex, MD5_DIGEST_SIZE, bin); + return std::string(reinterpret_cast<char const *>(hex), sizeof(hex)); +} + +std::string base64_encode (std::string const & s) { + struct base64_encode_ctx ctx; + base64_encode_init(&ctx); + uint8_t b64[BASE64_ENCODE_LENGTH(s.size())]; + auto len = base64_encode_update(&ctx, b64, s.size(), reinterpret_cast<uint8_t const *>(s.data())); + len += base64_encode_final(&ctx, b64 + len); + return std::string(reinterpret_cast<char const *>(b64), len); +} + +int make_upstream_agent_conn () { + char const * path; + int sock; + struct sockaddr_un addr; + + if (!(path = getenv("SSH_AUTH_SOCK"))) { + std::clog << "no $SSH_AUTH_SOCK" << std::endl; + exit(EX_UNAVAILABLE); + } + + if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) { + perror("socket"); + exit(EX_UNAVAILABLE); + } + + addr.sun_family = AF_UNIX; + + if (strlen(path) >= sizeof(addr.sun_path)) { + std::clog << "$SSH_AUTH_SOCK too long" << std::endl; + exit(EX_UNAVAILABLE); + } + + strcpy(addr.sun_path, path); + + if (connect(sock, reinterpret_cast<struct sockaddr const *>(&addr), sizeof(addr))) { + perror("connect"); + exit(EX_UNAVAILABLE); + } + + return sock; +} + +int make_listen_sock () { + int sock; + struct sockaddr_un addr; + + if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) { + perror("socket"); + exit(EX_UNAVAILABLE); + } + + addr.sun_family = AF_UNIX; + + if (path.native().length() >= sizeof(addr.sun_path)) { + std::clog << "path for listen socket too long" << std::endl; + exit(EX_UNAVAILABLE); + } + + strcpy(addr.sun_path, path.c_str()); + + if (bind(sock, reinterpret_cast<struct sockaddr const *>(&addr), sizeof(addr))) { + perror("bind"); + exit(EX_UNAVAILABLE); + } + + if (listen(sock, 0)) { + perror("listen"); + exit(EX_UNAVAILABLE); + } + + return sock; +} + +void parse_cmdline (int const argc, char const * const * const argv) { + po::options_description opts("OPTIONS"); + opts.add_options() + ("comment,c", po::value(&allowed_comment), "key specified by comment") + ("debug,d", po::bool_switch(&debug), "show even more stuff") + ("fingerprint,fp,f", po::value(&allowed_md5), "key specified by pubkey's hex-encoded md5 fingerprint") + ("help,h", "print this help message") + ("key,k", po::value(&allowed_b64), "key specified by base64-encoded pubkey") + ("version,V", "print version information") + ; + po::variables_map config; + po::store(po::parse_command_line(argc, argv, opts), config); + po::notify(config); + + if (config.count("help")) { + std::cout << "Invocation: ssh-agent-filter [ OPTIONS ] -- [ SSH ARGUMENTS ]" << std::endl; + std::cout << opts << std::endl; + exit(EX_OK); + } + + if (config.count("version")) { + std::cout << SSH_AGENT_FILTER_VERSION << std::endl; + exit(EX_OK); + } + + // canonicalize hashes + for (auto & s : allowed_md5) + for (auto it = s.begin(); it != s.end(); ) + if (isxdigit(*it)) { + *it = tolower(*it); + ++it; + } else + it = s.erase(it); +} + +void setup_filters () { + __gnu_cxx::stdio_filebuf<char> agent_filebuf(make_upstream_agent_conn(), std::ios::in | std::ios::out); + std::iostream agent(&agent_filebuf); + agent.exceptions(std::ios::badbit | std::ios::failbit); + + agent << rfc4251string(std::string(1, SSH2_AGENTC_REQUEST_IDENTITIES)); + rfc4251string answer; + agent >> answer; + std::istringstream answer_iss(answer); + answer_iss.exceptions(std::ios::badbit | std::ios::failbit); + rfc4251byte resp_code; + answer_iss >> resp_code; + if (resp_code != SSH2_AGENT_IDENTITIES_ANSWER) + throw std::runtime_error("unexpected answer from ssh-agent"); + rfc4251uint32 keycount; + answer_iss >> keycount; + for (uint32_t i = keycount; i; --i) { + rfc4251string key; + rfc4251string comment; + answer_iss >> key >> comment; + + auto b64 = base64_encode(key); + if (debug) std::clog << b64 << std::endl; + + auto md5 = md5_hex(key); + if (debug) std::clog << md5 << std::endl; + + std::string comm(comment); + if (debug) std::clog << comm << std::endl; + + if (std::count(allowed_b64.begin(), allowed_b64.end(), b64)) { + allowed_pubkeys.insert(key); + if (debug) std::clog << "key allowed by equal base64 representation" << std::endl; + } + if (std::count(allowed_md5.begin(), allowed_md5.end(), md5)) { + allowed_pubkeys.insert(key); + if (debug) std::clog << "key allowed by matching md5 fingerprint" << std::endl; + } + if (std::count(allowed_comment.begin(), allowed_comment.end(), comm)) { + allowed_pubkeys.insert(key); + if (debug) std::clog << "key allowed by matching comment" << std::endl; + } + + if (debug) std::clog << std::endl; + } +} + +rfc4251string handle_request (rfc4251string const & r) { + std::istringstream request(r); + std::ostringstream answer; + request.exceptions(std::ios::badbit | std::ios::failbit); + answer.exceptions(std::ios::badbit | std::ios::failbit); + rfc4251byte request_code; + request >> request_code; + switch (request_code) { + case SSH2_AGENTC_REQUEST_IDENTITIES: + { + __gnu_cxx::stdio_filebuf<char> agent_filebuf(make_upstream_agent_conn(), std::ios::in | std::ios::out); + std::iostream agent(&agent_filebuf); + agent.exceptions(std::ios::badbit | std::ios::failbit); + rfc4251string agent_answer; + agent << rfc4251string(std::string(1, SSH2_AGENTC_REQUEST_IDENTITIES)); + agent >> agent_answer; + // temp to test key filtering when signing + //return agent_answer; + std::istringstream agent_answer_iss(agent_answer); + rfc4251byte answer_code; + rfc4251uint32 keycount; + agent_answer_iss >> answer_code >> keycount; + if (answer_code != SSH2_AGENT_IDENTITIES_ANSWER) + throw std::runtime_error("unexpected answer from ssh-agent"); + std::vector<std::pair<rfc4251string, rfc4251string>> keys; + for (uint32_t i = keycount; i; --i) { + rfc4251string key; + rfc4251string comment; + agent_answer_iss >> key >> comment; + if (allowed_pubkeys.count(key)) + keys.emplace_back(std::move(key), std::move(comment)); + } + answer << answer_code << rfc4251uint32(keys.size()); + for (auto const & k : keys) + answer << k.first << k.second; + } + break; + case SSH2_AGENTC_SIGN_REQUEST: + { + rfc4251string key; + request >> key; + if (allowed_pubkeys.count(key)) { + __gnu_cxx::stdio_filebuf<char> agent_filebuf(make_upstream_agent_conn(), std::ios::in | std::ios::out); + std::iostream agent(&agent_filebuf); + agent.exceptions(std::ios::badbit | std::ios::failbit); + rfc4251string agent_answer; + + agent << r; + agent >> agent_answer; + return agent_answer; + } else + answer << rfc4251byte(SSH_AGENT_FAILURE); + } + break; + case SSH_AGENTC_REQUEST_RSA_IDENTITIES: + answer << rfc4251byte(SSH_AGENT_RSA_IDENTITIES_ANSWER); + // we got no SSHv1 keys + answer << rfc4251uint32(0); + break; + case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES: + answer << rfc4251byte(SSH_AGENT_SUCCESS); + break; + case SSH_AGENTC_RSA_CHALLENGE: + case SSH_AGENTC_ADD_RSA_IDENTITY: + case SSH_AGENTC_REMOVE_RSA_IDENTITY: + case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED: + case SSH2_AGENTC_ADD_IDENTITY: + case SSH2_AGENTC_REMOVE_IDENTITY: + case SSH2_AGENTC_REMOVE_ALL_IDENTITIES: + case SSH2_AGENTC_ADD_ID_CONSTRAINED: + case SSH_AGENTC_ADD_SMARTCARD_KEY: + case SSH_AGENTC_REMOVE_SMARTCARD_KEY: + case SSH_AGENTC_LOCK: + case SSH_AGENTC_UNLOCK: + case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED: + default: + answer << rfc4251byte(SSH_AGENT_FAILURE); + break; + } + + return rfc4251string(answer.str()); +} + +void handle_client (int const sock) { + // we could use only one streambuf and iostream but when + // switching from read to write an lseek call is made that + // fails with ESPIPE and causes an exception + __gnu_cxx::stdio_filebuf<char> client_filebuf_in(sock, std::ios::in); + __gnu_cxx::stdio_filebuf<char> client_filebuf_out(sock, std::ios::out); + std::istream client_in(&client_filebuf_in); + std::ostream client_out(&client_filebuf_out); + client_out.exceptions(std::ios::badbit | std::ios::failbit); + + rfc4251string request; + while (client_in >> request) try { + client_out << handle_request(request) << std::flush; + } catch (...) { + break; + } +} + +void sighandler (int sig) { + switch (sig) { + case SIGINT: + case SIGPIPE: + break; + default: + remove(path); + std::abort(); + } +} + +int main (int const argc, char const * const * const argv) { + parse_cmdline(argc, argv); + + setup_filters(); + + path = fs::current_path() / ("agent." + std::to_string(getpid())); + int listen_sock = make_listen_sock(); + + if (not debug) { + pid_t pid = fork(); + if (pid == -1) { + perror("fork"); + exit(EX_OSERR); + } + if (pid > 0) { + std::cout << "SSH_AUTH_SOCK='" << path << "'; export SSH_AUTH_SOCK;" << std::endl; + std::cout << "SSH_AGENT_PID='" << pid << "'; export SSH_AGENT_PID;" << std::endl; + std::cout << "echo 'Agent pid " << pid << "';" << std::endl; + exit(EX_OK); + } + + setsid(); + chdir("/"); + int devnull = open("/dev/null", O_RDWR); + dup2(devnull, 0); + dup2(devnull, 1); + dup2(devnull, 2); + close(devnull); + + signal(SIGINT, sighandler); + signal(SIGPIPE, sighandler); + signal(SIGHUP, sighandler); + signal(SIGTERM, sighandler); + } + + int client_sock; + while ((client_sock = accept(listen_sock, nullptr, nullptr)) != -1) { + std::thread t(handle_client, client_sock); + t.detach(); + } +} diff --git a/ssh-agent.h b/ssh-agent.h new file mode 100644 index 0000000..7824dc5 --- /dev/null +++ b/ssh-agent.h @@ -0,0 +1,55 @@ +/* + * ssh-agent.h + * + * constants copied from http://api.libssh.org/rfc/PROTOCOL.agent + * + * public domain. + */ + +// 3. Protocol message numbers + +// 3.1 Requests from client to agent for protocol 1 key operations + +#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 +#define SSH_AGENTC_RSA_CHALLENGE 3 +#define SSH_AGENTC_ADD_RSA_IDENTITY 7 +#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 +#define SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES 9 +#define SSH_AGENTC_ADD_RSA_ID_CONSTRAINED 24 + +// 3.2 Requests from client to agent for protocol 2 key operations + +#define SSH2_AGENTC_REQUEST_IDENTITIES 11 +#define SSH2_AGENTC_SIGN_REQUEST 13 +#define SSH2_AGENTC_ADD_IDENTITY 17 +#define SSH2_AGENTC_REMOVE_IDENTITY 18 +#define SSH2_AGENTC_REMOVE_ALL_IDENTITIES 19 +#define SSH2_AGENTC_ADD_ID_CONSTRAINED 25 + +// 3.3 Key-type independent requests from client to agent + +#define SSH_AGENTC_ADD_SMARTCARD_KEY 20 +#define SSH_AGENTC_REMOVE_SMARTCARD_KEY 21 +#define SSH_AGENTC_LOCK 22 +#define SSH_AGENTC_UNLOCK 23 +#define SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED 26 + +// 3.4 Generic replies from agent to client + +#define SSH_AGENT_FAILURE 5 +#define SSH_AGENT_SUCCESS 6 + +// 3.5 Replies from agent to client for protocol 1 key operations + +#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 +#define SSH_AGENT_RSA_RESPONSE 4 + +// 3.6 Replies from agent to client for protocol 2 key operations + +#define SSH2_AGENT_IDENTITIES_ANSWER 12 +#define SSH2_AGENT_SIGN_RESPONSE 14 + +// 3.7 Key constraint identifiers + +#define SSH_AGENT_CONSTRAIN_LIFETIME 1 +#define SSH_AGENT_CONSTRAIN_CONFIRM 2 |