From b2802053192ba0000866b145b715a557d34ed0eb Mon Sep 17 00:00:00 2001 From: Ben McGinnes Date: Thu, 4 Oct 2018 01:42:12 +1000 Subject: [PATCH] docs: pre-python preparation * doc/Makefile.am: removed the python howto from this file, restoring it to just the main project and the newer .js files. * deleted: doc/gpgme-python-howto.texi * renamed the Short_History.org file to short-history.org to keep the naming conventions similar. * All the Python files can (and should) live together. --- doc/Makefile.am | 6 +- doc/gpgme-python-howto.texi | 3133 ----------------- .../{Short_History.org => short-history.org} | 0 3 files changed, 1 insertion(+), 3138 deletions(-) delete mode 100644 doc/gpgme-python-howto.texi rename lang/python/docs/{Short_History.org => short-history.org} (100%) diff --git a/doc/Makefile.am b/doc/Makefile.am index a944be62..5f161a96 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -30,7 +30,7 @@ BUILT_SOURCES = defsincdate defs.inc info_TEXINFOS = gpgme.texi -gpgme_TEXINFOS = uiserver.texi gpgme-python-howto.texi lesser.texi gpl.texi +gpgme_TEXINFOS = uiserver.texi lesser.texi gpl.texi gpgme.texi : defs.inc @@ -60,7 +60,3 @@ online: gpgme.html gpgme.pdf gpgme-python-howto.html gpgme-python-howto.pdf (cd gpgme.html && rsync -vr --exclude='.svn' . \ $${user}@ftp.gnupg.org:webspace/manuals/gpgme/ ); \ rsync -v gpgme.pdf $${user}@ftp.gnupg.org:webspace/manuals/ - (cd gpgme-python-howto.html && rsync -vr --exclude='.svn' . \ - $${user}@ftp.gnupg.org:webspace/manuals/gpgme/ ); \ - rsync -v gpgme-python-howto.pdf $${user}@ftp.gnupg.org:webspace/manuals/ - diff --git a/doc/gpgme-python-howto.texi b/doc/gpgme-python-howto.texi deleted file mode 100644 index c88c7460..00000000 --- a/doc/gpgme-python-howto.texi +++ /dev/null @@ -1,3133 +0,0 @@ -\input texinfo @c -*- texinfo -*- -@c %**start of header -@setfilename gpgme-python-howto.info -@settitle GNU Privacy Guard (GnuPG) Made Easy Python Bindings HOWTO (English) -@documentencoding UTF-8 -@documentlanguage en -@c %**end of header - -@finalout -@titlepage -@title GNU Privacy Guard (GnuPG) Made Easy Python Bindings HOWTO (English) -@author Ben McGinnes -@end titlepage - -@contents - -@ifnottex -@node Top -@top GNU Privacy Guard (GnuPG) Made Easy Python Bindings HOWTO (English) -@end ifnottex - -@menu -* Introduction:: -* GPGME Concepts:: -* GPGME Python bindings installation:: -* Fundamentals:: -* Working with keys:: -* Basic Functions:: -* Creating keys and subkeys:: -* Advanced or Experimental Use Cases:: -* Miscellaneous extras and work-arounds:: -* Copyright and Licensing:: - -@detailmenu ---- The Detailed Node Listing --- - -Introduction - -* Python 2 versus Python 3:: -* Examples:: -* Unofficial Drafts:: -* What's New:: - -What's New - -* New in GPGME 1·12·0:: - -GPGME Concepts - -* A C API:: -* Python bindings:: -* Difference between the Python bindings and other GnuPG Python packages:: - -Difference between the Python bindings and other GnuPG Python packages - -* The python-gnupg package maintained by Vinay Sajip:: -* The gnupg package created and maintained by Isis Lovecruft:: -* The PyME package maintained by Martin Albrecht:: - -GPGME Python bindings installation - -* No PyPI:: -* Requirements:: -* Installation:: -* Known Issues:: - -Requirements - -* Recommended Additions:: - -Installation - -* Installing GPGME:: - -Known Issues - -* Breaking Builds:: -* Reinstalling Responsibly:: -* Multiple installations:: -* Won't Work With Windows:: -* CFFI is the Best™ and GPGME should use it instead of SWIG:: -* Virtualised Environments:: - -Fundamentals - -* No REST:: -* Context:: - -Working with keys - -* Key selection:: -* Get key:: -* Importing keys:: -* Exporting keys:: - -Key selection - -* Counting keys:: - -Importing keys - -* Working with ProtonMail:: -* Importing with HKP for Python:: -* Importing from ProtonMail with HKP for Python:: - -Exporting keys - -* Exporting public keys:: -* Exporting secret keys:: -* Sending public keys to the SKS Keyservers:: - -Basic Functions - -* Encryption:: -* Decryption:: -* Signing text and files:: -* Signature verification:: - -Encryption - -* Encrypting to one key:: -* Encrypting to multiple keys:: - -Signing text and files - -* Signing key selection:: -* Normal or default signing messages or files:: -* Detached signing messages and files:: -* Clearsigning messages or text:: - -Creating keys and subkeys - -* Primary key:: -* Subkeys:: -* User IDs:: -* Key certification:: - -User IDs - -* Adding User IDs:: -* Revokinging User IDs:: - -Advanced or Experimental Use Cases - -* C plus Python plus SWIG plus Cython:: - -Miscellaneous extras and work-arounds - -* Group lines:: -* Keyserver access for Python:: - -Keyserver access for Python - -* Key import format:: - -Copyright and Licensing - -* Copyright:: -* Draft Editions of this HOWTO:: -* License GPL compatible:: - -@end detailmenu -@end menu - -@node Introduction -@chapter Introduction - -@multitable {aaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} -@item Version: -@tab 0.1.4 -@item GPGME Version: -@tab 1.12.0 -@item Author: -@tab @uref{https://gnupg.org/people/index.html#sec-1-5, Ben McGinnes} -@item Author GPG Key: -@tab DB4724E6FA4286C92B4E55C4321E4E2373590E5D -@item Language: -@tab Australian English, British English -@item xml:lang: -@tab en-AU, en-GB, en -@end multitable - -This document provides basic instruction in how to use the GPGME -Python bindings to programmatically leverage the GPGME library. - -@menu -* Python 2 versus Python 3:: -* Examples:: -* Unofficial Drafts:: -* What's New:: -@end menu - -@node Python 2 versus Python 3 -@section Python 2 versus Python 3 - -Though the GPGME Python bindings themselves provide support for both -Python 2 and 3, the focus is unequivocally on Python 3 and -specifically from Python 3.4 and above. As a consequence all the -examples and instructions in this guide use Python 3 code. - -Much of it will work with Python 2, but much of it also deals with -Python 3 byte literals, particularly when reading and writing data. -Developers concentrating on Python 2.7, and possibly even 2.6, will -need to make the appropriate modifications to support the older string -and unicode types as opposed to bytes. - -There are multiple reasons for concentrating on Python 3; some of -which relate to the immediate integration of these bindings, some of -which relate to longer term plans for both GPGME and the python -bindings and some of which relate to the impending EOL period for -Python 2.7. Essentially, though, there is little value in tying the -bindings to a version of the language which is a dead end and the -advantages offered by Python 3 over Python 2 make handling the data -types with which GPGME deals considerably easier. - -@node Examples -@section Examples - -All of the examples found in this document can be found as Python 3 -scripts in the @samp{lang/python/examples/howto} directory. - -@node Unofficial Drafts -@section Unofficial Drafts - -In addition to shipping with each release of GPGME, there is a section -on locations to read or download @ref{Draft Editions of this HOWTO, , draft editions} of this document from -at the end of it. These are unofficial versions produced in between -major releases. - -@node What's New -@section What's New - -The most obviously new point for those reading this guide is this -section on other new things, but that's hardly important. Not given -all the other things which spurred the need for adding this section -and its subsections. - -@menu -* New in GPGME 1·12·0:: -@end menu - -@node New in GPGME 1·12·0 -@subsection New in GPGME 1·12·0 - -There have been quite a number of additions to GPGME and the Python -bindings to it since the last release of GPGME with versions 1.11.0 -and 1.11.1 in April, 2018. - -The bullet points of new additiions are: - -@itemize -@item -an expanded section on @ref{Installation, , installing} and @ref{Known Issues, , troubleshooting} the Python -bindings. -@item -The release of Python 3.7.0; which appears to be working just fine -with our bindings, in spite of intermittent reports of problems for -many other Python projects with that new release. -@item -Python 3.7 has been moved to the head of the specified python -versions list in the build process. -@item -In order to fix some other issues, there are certain underlying -functions which are more exposed through the @ref{Context, , gpg.Context()}, but -ongoing documentation ought to clarify that or otherwise provide the -best means of using the bindings. Some additions to @samp{gpg.core} and -the @samp{Context()}, however, were intended (see below). -@item -Continuing work in identifying and confirming the cause of -oft-reported @ref{Won't Work With Windows, , problems installing the Python bindings on Windows}. -@item -GSOC: Google's Surreptitiously Ordered Conscription @dots{} erm @dots{} oh, -right; Google's Summer of Code. Though there were two hopeful -candidates this year; only one ended up involved with the GnuPG -Project directly, the other concentrated on an unrelated third party -project with closer ties to one of the GNU/Linux distributions than -to the GnuPG Project. Thus the Python bindings benefited from GSOC -participant Jacob Adams, who added the key@math{_import} function; building -on prior work by Tobias Mueller. -@item -Several new methods functions were added to the gpg.Context(), -including: @ref{Importing keys, , key@math{_import}}, @ref{Exporting keys, , key@math{_export}}, @ref{Exporting public keys, , key@math{_export}@math{_minimal}} and -@ref{Exporting secret keys, , key@math{_export}@math{_secret}}. -@item -Importing and exporting examples include versions integrated with -Marcel Fest's recently released @uref{https://github.com/Selfnet/hkp4py, HKP for Python} module. Some -@ref{Keyserver access for Python, , additional notes on this module} are included at the end of the HOWTO. -@item -Instructions for dealing with semi-walled garden implementations -like ProtonMail are also included. This is intended to make things -a little easier when communicating with users of ProtonMail's -services and should not be construed as an endorsement of said -service. The GnuPG Project neither favours, nor disfavours -ProtonMail and the majority of this deals with interacting with the -ProtonMail keyserver. -@item -Semi-formalised the location where @ref{Draft Editions of this HOWTO, , draft versions} of this HOWTO may -periodically be accessible. This is both for the reference of -others and testing the publishing of the document itself. Renamed -the file at around the same time. -@item -Added a new section for @ref{Advanced or Experimental Use Cases, , advanced or experimental use}. -@item -Began the advanced use cases with @ref{C plus Python plus SWIG plus Cython, , a section} on using the module with -@uref{http://cython.org/, Cython}. -@item -Added a number of new scripts to the @samp{example/howto/} directory; -some of which may be in advance of their planned sections of the -HOWTO (and some are just there because it seemed like a good idea at -the time). -@item -Cleaned up a lot of things under the hood. -@end itemize - -@node GPGME Concepts -@chapter GPGME Concepts - -@menu -* A C API:: -* Python bindings:: -* Difference between the Python bindings and other GnuPG Python packages:: -@end menu - -@node A C API -@section A C API - -Unlike many modern APIs with which programmers will be more familiar -with these days, the GPGME API is a C API. The API is intended for -use by C coders who would be able to access its features by including -the @samp{gpgme.h} header file with their own C source code and then access -its functions just as they would any other C headers. - -This is a very effective method of gaining complete access to the API -and in the most efficient manner possible. It does, however, have the -drawback that it cannot be directly used by other languages without -some means of providing an interface to those languages. This is -where the need for bindings in various languages stems. - -@node Python bindings -@section Python bindings - -The Python bindings for GPGME provide a higher level means of -accessing the complete feature set of GPGME itself. It also provides -a more pythonic means of calling these API functions. - -The bindings are generated dynamically with SWIG and the copy of -@samp{gpgme.h} generated when GPGME is compiled. - -This means that a version of the Python bindings is fundamentally tied -to the exact same version of GPGME used to generate that copy of -@samp{gpgme.h}. - -@node Difference between the Python bindings and other GnuPG Python packages -@section Difference between the Python bindings and other GnuPG Python packages - -There have been numerous attempts to add GnuPG support to Python over -the years. Some of the most well known are listed here, along with -what differentiates them. - -@menu -* The python-gnupg package maintained by Vinay Sajip:: -* The gnupg package created and maintained by Isis Lovecruft:: -* The PyME package maintained by Martin Albrecht:: -@end menu - -@node The python-gnupg package maintained by Vinay Sajip -@subsection The python-gnupg package maintained by Vinay Sajip - -This is arguably the most popular means of integrating GPG with -Python. The package utilises the @samp{subprocess} module to implement -wrappers for the @samp{gpg} and @samp{gpg2} executables normally invoked on the -command line (@samp{gpg.exe} and @samp{gpg2.exe} on Windows). - -The popularity of this package stemmed from its ease of use and -capability in providing the most commonly required features. - -Unfortunately it has been beset by a number of security issues in the -past; most of which stemmed from using unsafe methods of accessing the -command line via the @samp{subprocess} calls. While some effort has been -made over the last two to three years (as of 2018) to mitigate this, -particularly by no longer providing shell access through those -subprocess calls, the wrapper is still somewhat limited in the scope -of its GnuPG features coverage. - -The python-gnupg package is available under the MIT license. - -@node The gnupg package created and maintained by Isis Lovecruft -@subsection The gnupg package created and maintained by Isis Lovecruft - -In 2015 Isis Lovecruft from the Tor Project forked and then -re-implemented the python-gnupg package as just gnupg. This new -package also relied on subprocess to call the @samp{gpg} or @samp{gpg2} -binaries, but did so somewhat more securely. - -The naming and version numbering selected for this package, however, -resulted in conflicts with the original python-gnupg and since its -functions were called in a different manner to python-gnupg, the -release of this package also resulted in a great deal of consternation -when people installed what they thought was an upgrade that -subsequently broke the code relying on it. - -The gnupg package is available under the GNU General Public License -version 3.0 (or any later version). - -@node The PyME package maintained by Martin Albrecht -@subsection The PyME package maintained by Martin Albrecht - -This package is the origin of these bindings, though they are somewhat -different now. For details of when and how the PyME package was -folded back into GPGME itself see the @emph{Short History} document@footnote{@samp{Short_History.org} and/or @samp{Short_History.html}.} -in the Python bindings @samp{docs} directory.@footnote{The @samp{lang/python/docs/} directory in the GPGME source.} - -The PyME package was first released in 2002 and was also the first -attempt to implement a low level binding to GPGME. In doing so it -provided access to considerably more functionality than either the -@samp{python-gnupg} or @samp{gnupg} packages. - -The PyME package is only available for Python 2.6 and 2.7. - -Porting the PyME package to Python 3.4 in 2015 is what resulted in it -being folded into the GPGME project and the current bindings are the -end result of that effort. - -The PyME package is available under the same dual licensing as GPGME -itself: the GNU General Public License version 2.0 (or any later -version) and the GNU Lesser General Public License version 2.1 (or any -later version). - -@node GPGME Python bindings installation -@chapter GPGME Python bindings installation - -@menu -* No PyPI:: -* Requirements:: -* Installation:: -* Known Issues:: -@end menu - -@node No PyPI -@section No PyPI - -Most third-party Python packages and modules are available and -distributed through the Python Package Installer, known as PyPI. - -Due to the nature of what these bindings are and how they work, it is -infeasible to install the GPGME Python bindings in the same way. - -This is because the bindings use SWIG to dynamically generate C -bindings against @samp{gpgme.h} and @samp{gpgme.h} is generated from -@samp{gpgme.h.in} at compile time when GPGME is built from source. Thus to -include a package in PyPI which actually built correctly would require -either statically built libraries for every architecture bundled with -it or a full implementation of C for each architecture. - -See the additional notes regarding @ref{CFFI is the Best™ and GPGME should use it instead of SWIG, , CFFI and SWIG} at the end of this -section for further details. - -@node Requirements -@section Requirements - -The GPGME Python bindings only have three requirements: - -@enumerate -@item -A suitable version of Python 2 or Python 3. With Python 2 that -means CPython 2.7 and with Python 3 that means CPython 3.4 or -higher. -@item -@uref{https://www.swig.org, SWIG}. -@item -GPGME itself. Which also means that all of GPGME's dependencies -must be installed too. -@end enumerate - -@menu -* Recommended Additions:: -@end menu - -@node Recommended Additions -@subsection Recommended Additions - -Though none of the following are absolute requirements, they are all -recommended for use with the Python bindings. In some cases these -recommendations refer to which version(s) of CPython to use the -bindings with, while others refer to third party modules which provide -a significant advantage in some way. - -@enumerate -@item -If possible, use Python 3 instead of 2. -@item -Favour a more recent version of Python since even 3.4 is due to -reach EOL soon. In production systems and services, Python 3.6 -should be robust enough to be relied on. -@item -If possible add the following Python modules which are not part of -the standard library: @uref{http://docs.python-requests.org/en/latest/index.html, Requests}, @uref{http://cython.org/, Cython} and @uref{https://github.com/Selfnet/hkp4py, hkp4py}. Chances are -quite high that at least the first one and maybe two of those will -already be installed. -@end enumerate - -Note that, as with Cython, some of the planned additions to the -@ref{Advanced or Experimental Use Cases, , Advanced} section, will bring with them additional requirements. Most -of these will be fairly well known and commonly installed ones, -however, which are in many cases likely to have already been installed -on many systems or be familiar to Python programmers. - -@node Installation -@section Installation - -Installing the Python bindings is effectively achieved by compiling -and installing GPGME itself. - -Once SWIG is installed with Python and all the dependencies for GPGME -are installed you only need to confirm that the version(s) of Python -you want the bindings installed for are in your @samp{$PATH}. - -By default GPGME will attempt to install the bindings for the most -recent or highest version number of Python 2 and Python 3 it detects -in @samp{$PATH}. It specifically checks for the @samp{python} and @samp{python3} -executables first and then checks for specific version numbers. - -For Python 2 it checks for these executables in this order: @samp{python}, -@samp{python2} and @samp{python2.7}. - -For Python 3 it checks for these executables in this order: @samp{python3}, - @samp{python3.7}, @samp{python3.6}, @samp{python3.5} and @samp{python3.4}.@footnote{With no issues reported specific to Python 3.7, the release of -Python 3.7.1 at around the same time as GPGME 1.12.0 and the testing -with Python 3.7.1rc1, there is no reason to delay moving 3.7 ahead of -3.6 now. Production environments with more conservative requirements -will always enforce their own policies anyway and installation to each -supported minor release is quite possible too.} - -On systems where @samp{python} is actually @samp{python3} and not @samp{python2} it -may be possible that @samp{python2} may be overlooked, but there have been -no reports of that actually occurring as yet. - -In the three months or so since the release of Python 3.7.0 there has -been extensive testing and work with these bindings with no issues -specifically relating to the new version of Python or any of the new -features of either the language or the bindings. This has also been -the case with Python 3.7.1rc1. With that in mind and given the -release of Python 3.7.1 is scheduled for around the same time as GPGME -1.12.0, the order of preferred Python versions has been changed to -move Python 3.7 ahead of Python 3.6. - -@menu -* Installing GPGME:: -@end menu - -@node Installing GPGME -@subsection Installing GPGME - -See the GPGME @samp{README} file for details of how to install GPGME from -source. - -@node Known Issues -@section Known Issues - -There are a few known issues with the current build process and the -Python bindings. For the most part these are easily addressed should -they be encountered. - -@menu -* Breaking Builds:: -* Reinstalling Responsibly:: -* Multiple installations:: -* Won't Work With Windows:: -* CFFI is the Best™ and GPGME should use it instead of SWIG:: -* Virtualised Environments:: -@end menu - -@node Breaking Builds -@subsection Breaking Builds - -Occasionally when installing GPGME with the Python bindings included -it may be observed that the @samp{make} portion of that process induces a -large very number of warnings and, eventually errors which end that -part of the build process. Yet following that with @samp{make check} and -@samp{make install} appears to work seamlessly. - -The cause of this is related to the way SWIG needs to be called to -dynamically generate the C bindings for GPGME in the first place. So -the entire process will always produce @samp{lang/python/python2-gpg/} and -@samp{lang/python/python3-gpg/} directories. These should contain the -build output generated during compilation, including the complete -bindings and module installed into @samp{site-packages}. - -Occasionally the errors in the early part or some other conflict -(e.g. not installing as @strong{@emph{root}} or @strong{@emph{su}}) may result in nothing -being installed to the relevant @samp{site-packages} directory and the -build directory missing a lot of expected files. Even when this -occurs, the solution is actually quite simple and will always work. - -That solution is simply to run the following commands as either the -@strong{root} user or prepended with @samp{sudo -H}@footnote{Yes, even if you use virtualenv with everything you do in -Python. If you want to install this module as just your user account -then you will need to manually configure, compile and install the -@emph{entire} GnuPG stack as that user as well. This includes libraries -which are not often installed that way. It can be done and there are -circumstances under which it is worthwhile, but generally only on -POSIX systems which utilise single user mode (some even require it).} in the @samp{lang/python/} -directory: - -@example -/path/to/pythonX.Y setup.py build -/path/to/pythonX.Y setup.py build -/path/to/pythonX.Y setup.py install -@end example - -Yes, the build command does need to be run twice. Yes, you still need -to run the potentially failing or incomplete steps during the -@samp{configure}, @samp{make} and @samp{make install} steps with installing GPGME. -This is because those steps generate a lot of essential files needed, -both by and in order to create, the bindings (including both the -@samp{setup.py} and @samp{gpgme.h} files). - -@enumerate -@item -IMPORTANT Note - - -If specifying a selected number of languages to create bindings for, -try to leave Python last. Currently the majority of the other -language bindings are also preceding Python of either version when -listed alphabetically and so that just happens by default currently. - -If Python is set to precede one of the other languages then it is -possible that the errors described here may interrupt the build -process before generating bindings for those other languages. In -these cases it may be preferable to configure all preferred language -bindings separately with alternative @samp{configure} steps for GPGME using -the @samp{--enable-languages=$LANGUAGE} option. -@end enumerate - -@node Reinstalling Responsibly -@subsection Reinstalling Responsibly - -Regardless of whether you're installing for one version of Python or -several, there will come a point where reinstallation is required. -With most Python module installations, the installed files go into the -relevant site-packages directory and are then forgotten about. Then -the module is upgraded, the new files are copied over the old and -that's the end of the matter. - -While the same is true of these bindings, there have been intermittent -issues observed on some platforms which have benefited significantly -from removing all the previous installations of the bindings before -installing the updated versions. - -Removing the previous version(s) is simply a matter of changing to the -relevant @samp{site-packages} directory for the version of Python in -question and removing the @samp{gpg/} directory and any accompanying -egg-info files for that module. - -In most cases this will require root or administration privileges on -the system, but the same is true of installing the module in the first -place. - -@node Multiple installations -@subsection Multiple installations - -For a veriety of reasons it may be either necessary or just preferable -to install the bindings to alternative installed Python versions which -meet the requirements of these bindings. - -On POSIX systems this will generally be most simply achieved by -running the manual installation commands (build, build, install) as -described in the previous section for each Python installation the -bindings need to be installed to. - -As per the SWIG documentation: the compilers, libraries and runtime -used to build GPGME and the Python Bindings @strong{must} match those used to -compile Python itself, including the version number(s) (at least going -by major version numbers and probably minor numbers too). - -On most POSIX systems, including OS X, this will very likely be the -case in most, if not all, cases. - -@node Won't Work With Windows -@subsection Won't Work With Windows - -There are semi-regular reports of Windows users having considerable -difficulty in installing and using the Python bindings at all. Very -often, possibly even always, these reports come from Cygwin users -and/or MinGW users and/or Msys2 users. Though not all of them have -been confirmed, it appears that these reports have also come from -people who installed Python using the Windows installer files from the -@uref{https://python.org, Python website} (i.e. mostly MSI installers, sometimes self-extracting -@samp{.exe} files). - -The Windows versions of Python are not built using Cygwin, MinGW or -Msys2; they're built using Microsoft Visual Studio. Furthermore the -version used is @emph{considerably} more advanced than the version which -MinGW obtained a small number of files from many years ago in order to -be able to compile anything at all. Not only that, but there are -changes to the version of Visual Studio between some micro releases, -though that is is particularly the case with Python 2.7, since it has -been kept around far longer than it should have been. - -There are two theoretical solutions to this issue: - -@enumerate -@item -Compile and install the GnuPG stack, including GPGME and the -Python bibdings using the same version of Microsoft Visual Studio -used by the Python Foundation to compile the version of Python -installed. - -If there are multiple versions of Python then this will need to be -done with each different version of Visual Studio used. - -@item -Compile and install Python using the same tools used by choice, -such as MinGW or Msys2. -@end enumerate - -Do @strong{not} use the official Windows installer for Python unless -following the first method. - -In this type of situation it may even be for the best to accept that -there are less limitations on permissive software than free software -and simply opt to use a recent version of the Community Edition of -Microsoft Visual Studio to compile and build all of it, no matter -what. - -Investigations into the extent or the limitations of this issue are -ongoing. - -@node CFFI is the Best™ and GPGME should use it instead of SWIG -@subsection CFFI is the Best™ and GPGME should use it instead of SWIG - -There are many reasons for favouring @uref{https://cffi.readthedocs.io/en/latest/overview.html, CFFI} and proponents of it are -quite happy to repeat these things as if all it would take to switch -from SWIG to CFFI is repeating that list as if it were a new concept. - -The fact is that there are things which Python's CFFI implementation -cannot handle in the GPGME C code. Beyond that there are features of -SWIG which are simply not available with CFFI at all. SWIG generates -the bindings to Python using the @samp{gpgme.h} file, but that file is not -a single version shipped with each release, it too is generated when -GPGME is compiled. - -CFFI is currently unable to adapt to such a potentially mutable -codebase. If there were some means of applying SWIG's dynamic code -generation to produce the Python/CFFI API modes of accessing the GPGME -libraries (or the source source code directly), but such a thing does -not exist yet either and it currently appears that work is needed in -at least one of CFFI's dependencies before any of this can be -addressed. - -So if you're a massive fan of CFFI; that's great, but if you want this -project to switch to CFFI then rather than just insisting that it -should, I'd suggest you volunteer to bring CFFI up to the level this -project needs. - -If you're actually seriously considering doing so, then I'd suggest -taking the @samp{gpgme-tool.c} file in the GPGME @samp{src/} directory and -getting that to work with any of the CFFI API methods (not the ABI -methods, they'll work with pretty much anything). When you start -running into trouble with "ifdefs" then you'll know what sort of -things are lacking. That doesn't even take into account the amount of -work saved via SWIG's code generation techniques either. - -@node Virtualised Environments -@subsection Virtualised Environments - -It is fairly common practice amongst Python developers to, as much as -possible, use packages like virtualenv to keep various things that are -to be installed from interfering with each other. Given how much of -the GPGME bindings is often at odds with the usual pythonic way of -doing things, it stands to reason that this would be called into -question too. - -As it happens the answer as to whether or not the bindings can be used -with virtualenv, the answer is both yes and no. - -In general we recommend installing to the relevant path and matching -prefix of GPGME itself. Which means that when GPGME, and ideally the -rest of the GnuPG stack, is installed to a prefix like @samp{/usr/local} or -@samp{/opt/local} then the bindings would need to be installed to the main -Python installation and not a virtualised abstraction. Attempts to -separate the two in the past have been known to cause weird and -intermittent errors ranging from minor annoyances to complete failures -in the build process. - -As a consequence we only recommend building with and installing to the -main Python installations within the same prefix as GPGME is installed -to or which are found by GPGME's configuration stage immediately prior -to running the make commands. Which is exactly what the compiling and -installing process of GPGME does by default. - -Once that is done, however, it appears that a copy the compiled module -may be installed into a virtualenv of the same major and minor version -matching the build. Alternatively it is possible to utilise a -@samp{sites.pth} file in the @samp{site-packages/} directory of a viertualenv -installation, which links back to the system installations -corresponding directory in order to import anything installed system -wide. This may or may not be appropriate on a case by case basis. - -Though extensive testing of either of these options is not yet -complete, preliminary testing of them indicates that both are viable -as long as the main installation is complete. Which means that -certain other options normally restricted to virtual environments are -also available, including integration with pythonic test suites -(e.g. @uref{https://docs.pytest.org/en/latest/index.html, pytest}) and other large projects. - -That said, it is worth reiterating the warning regarding non-standard -installations. If one were to attempt to install the bindings only to -a virtual environment without somehow also including the full GnuPG -stack (or enough of it as to include GPGME) then it is highly likely -that errors would be encountered at some point and more than a little -likely that the build process itself would break. - -If a degree of separation from the main operating system is still -required in spite of these warnings, then consider other forms of -virtualisation. Either a virtual machine (e.g. @uref{https://www.virtualbox.org/, VirtualBox}), a -hardware emulation layer (e.g. @uref{https://www.qemu.org/, QEMU}) or an application container -(e.g. @uref{https://www.docker.com/why-docker, Docker}). - -Finally it should be noted that the limited tests conducted thus far -have been using the @samp{virtualenv} command in a new directory to create -the virtual python environment. As opposed to the standard @samp{python3 --m venv} and it is possible that this will make a difference depending -on the system and version of Python in use. Another option is to run -the command @samp{python3 -m virtualenv /path/to/install/virtual/thingy} -instead. - -@node Fundamentals -@chapter Fundamentals - -Before we can get to the fun stuff, there are a few matters regarding -GPGME's design which hold true whether you're dealing with the C code -directly or these Python bindings. - -@menu -* No REST:: -* Context:: -@end menu - -@node No REST -@section No REST - -The first part of which is or will be fairly blatantly obvious upon -viewing the first example, but it's worth reiterating anyway. That -being that this API is @emph{@strong{not}} a REST API. Nor indeed could it ever -be one. - -Most, if not all, Python programmers (and not just Python programmers) -know how easy it is to work with a RESTful API. In fact they've -become so popular that many other APIs attempt to emulate REST-like -behaviour as much as they are able. Right down to the use of JSON -formatted output to facilitate the use of their API without having to -retrain developers. - -This API does not do that. It would not be able to do that and also -provide access to the entire C API on which it's built. It does, -however, provide a very pythonic interface on top of the direct -bindings and it's this pythonic layer that this HOWTO deals with. - -@node Context -@section Context - -One of the reasons which prevents this API from being RESTful is that -most operations require more than one instruction to the API to -perform the task. Sure, there are certain functions which can be -performed simultaneously, particularly if the result known or strongly -anticipated (e.g. selecting and encrypting to a key known to be in the -public keybox). - -There are many more, however, which cannot be manipulated so readily: -they must be performed in a specific sequence and the result of one -operation has a direct bearing on the outcome of subsequent -operations. Not merely by generating an error either. - -When dealing with this type of persistent state on the web, full of -both the RESTful and REST-like, it's most commonly referred to as a -session. In GPGME, however, it is called a context and every -operation type has one. - -@node Working with keys -@chapter Working with keys - -@menu -* Key selection:: -* Get key:: -* Importing keys:: -* Exporting keys:: -@end menu - -@node Key selection -@section Key selection - -Selecting keys to encrypt to or to sign with will be a common -occurrence when working with GPGMe and the means available for doing -so are quite simple. - -They do depend on utilising a Context; however once the data is -recorded in another variable, that Context does not need to be the -same one which subsequent operations are performed. - -The easiest way to select a specific key is by searching for that -key's key ID or fingerprint, preferably the full fingerprint without -any spaces in it. A long key ID will probably be okay, but is not -advised and short key IDs are already a problem with some being -generated to match specific patterns. It does not matter whether the -pattern is upper or lower case. - -So this is the best method: - -@example -import gpg - -k = gpg.Context().keylist(pattern="258E88DCBD3CD44D8E7AB43F6ECB6AF0DEADBEEF") -keys = list(k) -@end example - -This is passable and very likely to be common: - -@example -import gpg - -k = gpg.Context().keylist(pattern="0x6ECB6AF0DEADBEEF") -keys = list(k) -@end example - -And this is a really bad idea: - -@example -import gpg - -k = gpg.Context().keylist(pattern="0xDEADBEEF") -keys = list(k) -@end example - -Alternatively it may be that the intention is to create a list of keys -which all match a particular search string. For instance all the -addresses at a particular domain, like this: - -@example -import gpg - -ncsc = gpg.Context().keylist(pattern="ncsc.mil") -nsa = list(ncsc) -@end example - -@menu -* Counting keys:: -@end menu - -@node Counting keys -@subsection Counting keys - -Counting the number of keys in your public keybox (@samp{pubring.kbx}), the -format which has superseded the old keyring format (@samp{pubring.gpg} and -@samp{secring.gpg}), or the number of secret keys is a very simple task. - -@example -import gpg - -c = gpg.Context() -seckeys = c.keylist(pattern=None, secret=True) -pubkeys = c.keylist(pattern=None, secret=False) - -seclist = list(seckeys) -secnum = len(seclist) - -publist = list(pubkeys) -pubnum = len(publist) - -print(""" - Number of secret keys: @{0@} - Number of public keys: @{1@} -""".format(secnum, pubnum)) -@end example - -@strong{NOTE:} The @ref{C plus Python plus SWIG plus Cython, , Cython} introduction in the @ref{Advanced or Experimental Use Cases, , Advanced and Experimental} -section uses this same key counting code with Cython to demonstrate -some areas where Cython can improve performance even with the -bindings. Users with large public keyrings or keyboxes, for instance, -should consider these options if they are comfortable with using -Cython. - -@node Get key -@section Get key - -An alternative method of getting a single key via its fingerprint is -available directly within a Context with @samp{Context().get_key}. This is -the preferred method of selecting a key in order to modify it, sign or -certify it and for obtaining relevant data about a single key as a -part of other functions; when verifying a signature made by that key, -for instance. - -By default this method will select public keys, but it can select -secret keys as well. - -This first example demonstrates selecting the current key of Werner -Koch, which is due to expire at the end of 2018: - -@example -import gpg - -fingerprint = "80615870F5BAD690333686D0F2AD85AC1E42B367" -key = gpg.Context().get_key(fingerprint) -@end example - -Whereas this example demonstrates selecting the author's current key -with the @samp{secret} key word argument set to @samp{True}: - -@example -import gpg - -fingerprint = "DB4724E6FA4286C92B4E55C4321E4E2373590E5D" -key = gpg.Context().get_key(fingerprint, secret=True) -@end example - -It is, of course, quite possible to select expired, disabled and -revoked keys with this function, but only to effectively display -information about those keys. - -It is also possible to use both unicode or string literals and byte -literals with the fingerprint when getting a key in this way. - -@node Importing keys -@section Importing keys - -Importing keys is possible with the @samp{key_import()} method and takes -one argument which is a bytes literal object containing either the -binary or ASCII armoured key data for one or more keys. - -The following example retrieves one or more keys from the SKS -keyservers via the web using the requests module. Since requests -returns the content as a bytes literal object, we can then use that -directly to import the resulting data into our keybox. - -@example -import gpg -import os.path -import requests - -c = gpg.Context() -url = "https://sks-keyservers.net/pks/lookup" -pattern = input("Enter the pattern to search for key or user IDs: ") -payload = @{"op": "get", "search": pattern@} - -r = requests.get(url, verify=True, params=payload) -result = c.key_import(r.content) - -if result is not None and hasattr(result, "considered") is False: - print(result) -elif result is not None and hasattr(result, "considered") is True: - num_keys = len(result.imports) - new_revs = result.new_revocations - new_sigs = result.new_signatures - new_subs = result.new_sub_keys - new_uids = result.new_user_ids - new_scrt = result.secret_imported - nochange = result.unchanged - print(""" - The total number of keys considered for import was: @{0@} - - Number of keys revoked: @{1@} - Number of new signatures: @{2@} - Number of new subkeys: @{3@} - Number of new user IDs: @{4@} - Number of new secret keys: @{5@} - Number of unchanged keys: @{6@} - - The key IDs for all considered keys were: -""".format(num_keys, new_revs, new_sigs, new_subs, new_uids, new_scrt, - nochange)) - for i in range(num_keys): - print("@{0@}\n".format(result.imports[i].fpr)) -else: - pass -@end example - -@strong{NOTE:} When searching for a key ID of any length or a fingerprint -(without spaces), the SKS servers require the the leading @samp{0x} -indicative of hexadecimal be included. Also note that the old short -key IDs (e.g. @samp{0xDEADBEEF}) should no longer be used due to the -relative ease by which such key IDs can be reproduced, as demonstrated -by the Evil32 Project in 2014 (which was subsequently exploited in -2016). - -@menu -* Working with ProtonMail:: -* Importing with HKP for Python:: -* Importing from ProtonMail with HKP for Python:: -@end menu - -@node Working with ProtonMail -@subsection Working with ProtonMail - -Here is a variation on the example above which checks the constrained -ProtonMail keyserver for ProtonMail public keys. - -@example -import gpg -import requests -import sys - -print(""" -This script searches the ProtonMail key server for the specified key and -imports it. -""") - -c = gpg.Context(armor=True) -url = "https://api.protonmail.ch/pks/lookup" -ksearch = [] - -if len(sys.argv) >= 2: - keyterm = sys.argv[1] -else: - keyterm = input("Enter the key ID, UID or search string: ") - -if keyterm.count("@@") == 2 and keyterm.startswith("@@") is True: - ksearch.append(keyterm[1:]) - ksearch.append(keyterm[1:]) - ksearch.append(keyterm[1:]) -elif keyterm.count("@@") == 1 and keyterm.startswith("@@") is True: - ksearch.append("@{0@}@@protonmail.com".format(keyterm[1:])) - ksearch.append("@{0@}@@protonmail.ch".format(keyterm[1:])) - ksearch.append("@{0@}@@pm.me".format(keyterm[1:])) -elif keyterm.count("@@") == 0: - ksearch.append("@{0@}@@protonmail.com".format(keyterm)) - ksearch.append("@{0@}@@protonmail.ch".format(keyterm)) - ksearch.append("@{0@}@@pm.me".format(keyterm)) -elif keyterm.count("@@") == 2 and keyterm.startswith("@@") is False: - uidlist = keyterm.split("@@") - for uid in uidlist: - ksearch.append("@{0@}@@protonmail.com".format(uid)) - ksearch.append("@{0@}@@protonmail.ch".format(uid)) - ksearch.append("@{0@}@@pm.me".format(uid)) -elif keyterm.count("@@") > 2: - uidlist = keyterm.split("@@") - for uid in uidlist: - ksearch.append("@{0@}@@protonmail.com".format(uid)) - ksearch.append("@{0@}@@protonmail.ch".format(uid)) - ksearch.append("@{0@}@@pm.me".format(uid)) -else: - ksearch.append(keyterm) - -for k in ksearch: - payload = @{"op": "get", "search": k@} - try: - r = requests.get(url, verify=True, params=payload) - if r.ok is True: - result = c.key_import(r.content) - elif r.ok is False: - result = r.content - except Exception as e: - result = None - - if result is not None and hasattr(result, "considered") is False: - print("@{0@} for @{1@}".format(result.decode(), k)) - elif result is not None and hasattr(result, "considered") is True: - num_keys = len(result.imports) - new_revs = result.new_revocations - new_sigs = result.new_signatures - new_subs = result.new_sub_keys - new_uids = result.new_user_ids - new_scrt = result.secret_imported - nochange = result.unchanged - print(""" -The total number of keys considered for import was: @{0@} - -With UIDs wholely or partially matching the following string: - - @{1@} - - Number of keys revoked: @{2@} - Number of new signatures: @{3@} - Number of new subkeys: @{4@} - Number of new user IDs: @{5@} -Number of new secret keys: @{6@} - Number of unchanged keys: @{7@} - -The key IDs for all considered keys were: -""".format(num_keys, k, new_revs, new_sigs, new_subs, new_uids, new_scrt, - nochange)) - for i in range(num_keys): - print(result.imports[i].fpr) - print("") - elif result is None: - print(e) -@end example - -Both the above example, @uref{../examples/howto/pmkey-import.py, pmkey-import.py}, and a version which prompts -for an alternative GnuPG home directory, @uref{../examples/howto/pmkey-import-alt.py, pmkey-import-alt.py}, are -available with the other examples and are executable scripts. - -Note that while the ProtonMail servers are based on the SKS servers, -their server is related more to their API and is not feature complete -by comparison to the servers in the SKS pool. One notable difference -being that the ProtonMail server does not permit non ProtonMail users -to update their own keys, which could be a vector for attacking -ProtonMail users who may not receive a key's revocation if it had been -compromised. - -@node Importing with HKP for Python -@subsection Importing with HKP for Python - -Performing the same tasks with the @uref{https://github.com/Selfnet/hkp4py, hkp4py module} (available via PyPI) -is not too much different, but does provide a number of options of -benefit to end users. Not least of which being the ability to perform -some checks on a key before importing it or not. For instance it may -be the policy of a site or project to only import keys which have not -been revoked. The hkp4py module permits such checks prior to the -importing of the keys found. - -@example -import gpg -import hkp4py -import sys - -c = gpg.Context() -server = hkp4py.KeyServer("hkps://hkps.pool.sks-keyservers.net") -results = [] - -if len(sys.argv) > 2: - pattern = " ".join(sys.argv[1:]) -elif len(sys.argv) == 2: - pattern = sys.argv[1] -else: - pattern = input("Enter the pattern to search for keys or user IDs: ") - -try: - keys = server.search(pattern) - print("Found @{0@} key(s).".format(len(keys))) -except Exception as e: - keys = [] - for logrus in pattern.split(): - if logrus.startswith("0x") is True: - key = server.search(logrus) - else: - key = server.search("0x@{0@}".format(logrus)) - keys.append(key[0]) - print("Found @{0@} key(s).".format(len(keys))) - -for key in keys: - import_result = c.key_import(key.key_blob) - results.append(import_result) - -for result in results: - if result is not None and hasattr(result, "considered") is False: - print(result) - elif result is not None and hasattr(result, "considered") is True: - num_keys = len(result.imports) - new_revs = result.new_revocations - new_sigs = result.new_signatures - new_subs = result.new_sub_keys - new_uids = result.new_user_ids - new_scrt = result.secret_imported - nochange = result.unchanged - print(""" -The total number of keys considered for import was: @{0@} - - Number of keys revoked: @{1@} - Number of new signatures: @{2@} - Number of new subkeys: @{3@} - Number of new user IDs: @{4@} -Number of new secret keys: @{5@} - Number of unchanged keys: @{6@} - -The key IDs for all considered keys were: -""".format(num_keys, new_revs, new_sigs, new_subs, new_uids, new_scrt, - nochange)) - for i in range(num_keys): - print(result.imports[i].fpr) - print("") - else: - pass -@end example - -Since the hkp4py module handles multiple keys just as effectively as -one (@samp{keys} is a list of responses per matching key), the example -above is able to do a little bit more with the returned data before -anything is actually imported. - -@node Importing from ProtonMail with HKP for Python -@subsection Importing from ProtonMail with HKP for Python - -Though this can provide certain benefits even when working with -ProtonMail, the scope is somewhat constrained there due to the -limitations of the ProtonMail keyserver. - -For instance, searching the SKS keyserver pool for the term "gnupg" -produces hundreds of results from any time the word appears in any -part of a user ID. Performing the same search on the ProtonMail -keyserver returns zero results, even though there are at least two -test accounts which include it as part of the username. - -The cause of this discrepancy is the deliberate configuration of that -server by ProtonMail to require an exact match of the full email -address of the ProtonMail user whose key is being requested. -Presumably this is intended to reduce breaches of privacy of their -users as an email address must already be known before a key for that -address can be obtained. - -@enumerate -@item -Import from ProtonMail via HKP for Python Example no. 1 - - -The following script is avalable with the rest of the examples under -the somewhat less than original name, @samp{pmkey-import-hkp.py}. - -@example -import gpg -import hkp4py -import os.path -import sys - -print(""" -This script searches the ProtonMail key server for the specified key and -imports it. - -Usage: pmkey-import-hkp.py [search strings] -""") - -c = gpg.Context(armor=True) -server = hkp4py.KeyServer("hkps://api.protonmail.ch") -keyterms = [] -ksearch = [] -allkeys = [] -results = [] -paradox = [] -homeless = None - -if len(sys.argv) > 2: - keyterms = sys.argv[1:] -elif len(sys.argv) == 2: - keyterm = sys.argv[1] - keyterms.append(keyterm) -else: - key_term = input("Enter the key ID, UID or search string: ") - keyterms = key_term.split() - -for keyterm in keyterms: - if keyterm.count("@@") == 2 and keyterm.startswith("@@") is True: - ksearch.append(keyterm[1:]) - ksearch.append(keyterm[1:]) - ksearch.append(keyterm[1:]) - elif keyterm.count("@@") == 1 and keyterm.startswith("@@") is True: - ksearch.append("@{0@}@@protonmail.com".format(keyterm[1:])) - ksearch.append("@{0@}@@protonmail.ch".format(keyterm[1:])) - ksearch.append("@{0@}@@pm.me".format(keyterm[1:])) - elif keyterm.count("@@") == 0: - ksearch.append("@{0@}@@protonmail.com".format(keyterm)) - ksearch.append("@{0@}@@protonmail.ch".format(keyterm)) - ksearch.append("@{0@}@@pm.me".format(keyterm)) - elif keyterm.count("@@") == 2 and keyterm.startswith("@@") is False: - uidlist = keyterm.split("@@") - for uid in uidlist: - ksearch.append("@{0@}@@protonmail.com".format(uid)) - ksearch.append("@{0@}@@protonmail.ch".format(uid)) - ksearch.append("@{0@}@@pm.me".format(uid)) - elif keyterm.count("@@") > 2: - uidlist = keyterm.split("@@") - for uid in uidlist: - ksearch.append("@{0@}@@protonmail.com".format(uid)) - ksearch.append("@{0@}@@protonmail.ch".format(uid)) - ksearch.append("@{0@}@@pm.me".format(uid)) - else: - ksearch.append(keyterm) - -for k in ksearch: - print("Checking for key for: @{0@}".format(k)) - try: - keys = server.search(k) - if isinstance(keys, list) is True: - for key in keys: - allkeys.append(key) - try: - import_result = c.key_import(key.key_blob) - except Exception as e: - import_result = c.key_import(key.key) - else: - paradox.append(keys) - import_result = None - except Exception as e: - import_result = None - results.append(import_result) - -for result in results: - if result is not None and hasattr(result, "considered") is False: - print("@{0@} for @{1@}".format(result.decode(), k)) - elif result is not None and hasattr(result, "considered") is True: - num_keys = len(result.imports) - new_revs = result.new_revocations - new_sigs = result.new_signatures - new_subs = result.new_sub_keys - new_uids = result.new_user_ids - new_scrt = result.secret_imported - nochange = result.unchanged - print(""" -The total number of keys considered for import was: @{0@} - -With UIDs wholely or partially matching the following string: - - @{1@} - - Number of keys revoked: @{2@} - Number of new signatures: @{3@} - Number of new subkeys: @{4@} - Number of new user IDs: @{5@} -Number of new secret keys: @{6@} - Number of unchanged keys: @{7@} - -The key IDs for all considered keys were: -""".format(num_keys, k, new_revs, new_sigs, new_subs, new_uids, new_scrt, - nochange)) - for i in range(num_keys): - print(result.imports[i].fpr) - print("") - elif result is None: - pass -@end example - -@item -Import from ProtonMail via HKP for Python Example no. 2 - - -Like its counterpart above, this script can also be found with the -rest of the examples, by the name pmkey-import-hkp-alt.py. - -With this script a modicum of effort has been made to treat anything -passed as a @samp{homedir} which either does not exist or which is not a -directory, as also being a pssible user ID to check for. It's not -guaranteed to pick up on all such cases, but it should cover most of -them. - -@example -import gpg -import hkp4py -import os.path -import sys - -print(""" -This script searches the ProtonMail key server for the specified key and -imports it. Optionally enables specifying a different GnuPG home directory. - -Usage: pmkey-import-hkp.py [homedir] [search string] - or: pmkey-import-hkp.py [search string] -""") - -c = gpg.Context(armor=True) -server = hkp4py.KeyServer("hkps://api.protonmail.ch") -keyterms = [] -ksearch = [] -allkeys = [] -results = [] -paradox = [] -homeless = None - -if len(sys.argv) > 3: - homedir = sys.argv[1] - keyterms = sys.argv[2:] -elif len(sys.argv) == 3: - homedir = sys.argv[1] - keyterm = sys.argv[2] - keyterms.append(keyterm) -elif len(sys.argv) == 2: - homedir = "" - keyterm = sys.argv[1] - keyterms.append(keyterm) -else: - keyterm = input("Enter the key ID, UID or search string: ") - homedir = input("Enter the GPG configuration directory path (optional): ") - keyterms.append(keyterm) - -if len(homedir) == 0: - homedir = None - homeless = False - -if homedir is not None: - if homedir.startswith("~"): - if os.path.exists(os.path.expanduser(homedir)) is True: - if os.path.isdir(os.path.expanduser(homedir)) is True: - c.home_dir = os.path.realpath(os.path.expanduser(homedir)) - else: - homeless = True - else: - homeless = True - elif os.path.exists(os.path.realpath(homedir)) is True: - if os.path.isdir(os.path.realpath(homedir)) is True: - c.home_dir = os.path.realpath(homedir) - else: - homeless = True - else: - homeless = True - -# First check to see if the homedir really is a homedir and if not, treat it as -# a search string. -if homeless is True: - keyterms.append(homedir) - c.home_dir = None -else: - pass - -for keyterm in keyterms: - if keyterm.count("@@") == 2 and keyterm.startswith("@@") is True: - ksearch.append(keyterm[1:]) - ksearch.append(keyterm[1:]) - ksearch.append(keyterm[1:]) - elif keyterm.count("@@") == 1 and keyterm.startswith("@@") is True: - ksearch.append("@{0@}@@protonmail.com".format(keyterm[1:])) - ksearch.append("@{0@}@@protonmail.ch".format(keyterm[1:])) - ksearch.append("@{0@}@@pm.me".format(keyterm[1:])) - elif keyterm.count("@@") == 0: - ksearch.append("@{0@}@@protonmail.com".format(keyterm)) - ksearch.append("@{0@}@@protonmail.ch".format(keyterm)) - ksearch.append("@{0@}@@pm.me".format(keyterm)) - elif keyterm.count("@@") == 2 and keyterm.startswith("@@") is False: - uidlist = keyterm.split("@@") - for uid in uidlist: - ksearch.append("@{0@}@@protonmail.com".format(uid)) - ksearch.append("@{0@}@@protonmail.ch".format(uid)) - ksearch.append("@{0@}@@pm.me".format(uid)) - elif keyterm.count("@@") > 2: - uidlist = keyterm.split("@@") - for uid in uidlist: - ksearch.append("@{0@}@@protonmail.com".format(uid)) - ksearch.append("@{0@}@@protonmail.ch".format(uid)) - ksearch.append("@{0@}@@pm.me".format(uid)) - else: - ksearch.append(keyterm) - -for k in ksearch: - print("Checking for key for: @{0@}".format(k)) - try: - keys = server.search(k) - if isinstance(keys, list) is True: - for key in keys: - allkeys.append(key) - try: - import_result = c.key_import(key.key_blob) - except Exception as e: - import_result = c.key_import(key.key) - else: - paradox.append(keys) - import_result = None - except Exception as e: - import_result = None - results.append(import_result) - -for result in results: - if result is not None and hasattr(result, "considered") is False: - print("@{0@} for @{1@}".format(result.decode(), k)) - elif result is not None and hasattr(result, "considered") is True: - num_keys = len(result.imports) - new_revs = result.new_revocations - new_sigs = result.new_signatures - new_subs = result.new_sub_keys - new_uids = result.new_user_ids - new_scrt = result.secret_imported - nochange = result.unchanged - print(""" -The total number of keys considered for import was: @{0@} - -With UIDs wholely or partially matching the following string: - - @{1@} - - Number of keys revoked: @{2@} - Number of new signatures: @{3@} - Number of new subkeys: @{4@} - Number of new user IDs: @{5@} -Number of new secret keys: @{6@} - Number of unchanged keys: @{7@} - -The key IDs for all considered keys were: -""".format(num_keys, k, new_revs, new_sigs, new_subs, new_uids, new_scrt, - nochange)) - for i in range(num_keys): - print(result.imports[i].fpr) - print("") - elif result is None: - pass -@end example -@end enumerate - -@node Exporting keys -@section Exporting keys - -Exporting keys remains a reasonably simple task, but has been -separated into three different functions for the OpenPGP cryptographic -engine. Two of those functions are for exporting public keys and the -third is for exporting secret keys. - -@menu -* Exporting public keys:: -* Exporting secret keys:: -* Sending public keys to the SKS Keyservers:: -@end menu - -@node Exporting public keys -@subsection Exporting public keys - -There are two methods of exporting public keys, both of which are very -similar to the other. The default method, @samp{key_export()}, will export -a public key or keys matching a specified pattern as normal. The -alternative, the @samp{key_export_minimal()} method, will do the same thing -except producing a minimised output with extra signatures and third -party signatures or certifications removed. - -@example -import gpg -import os.path -import sys - -print(""" -This script exports one or more public keys. -""") - -c = gpg.Context(armor=True) - -if len(sys.argv) >= 4: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = sys.argv[3] -elif len(sys.argv) == 3: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = input("Enter the GPG configuration directory path (optional): ") -elif len(sys.argv) == 2: - keyfile = sys.argv[1] - logrus = input("Enter the UID matching the key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") -else: - keyfile = input("Enter the path and filename to save the secret key to: ") - logrus = input("Enter the UID matching the key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") - -if homedir.startswith("~"): - if os.path.exists(os.path.expanduser(homedir)) is True: - c.home_dir = os.path.expanduser(homedir) - else: - pass -elif os.path.exists(homedir) is True: - c.home_dir = homedir -else: - pass - -try: - result = c.key_export(pattern=logrus) -except: - result = c.key_export(pattern=None) - -if result is not None: - with open(keyfile, "wb") as f: - f.write(result) -else: - pass -@end example - -It should be noted that the result will only return @samp{None} when a -search pattern has been entered, but has not matched any keys. When -the search pattern itself is set to @samp{None} this triggers the exporting -of the entire public keybox. - -@example -import gpg -import os.path -import sys - -print(""" -This script exports one or more public keys in minimised form. -""") - -c = gpg.Context(armor=True) - -if len(sys.argv) >= 4: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = sys.argv[3] -elif len(sys.argv) == 3: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = input("Enter the GPG configuration directory path (optional): ") -elif len(sys.argv) == 2: - keyfile = sys.argv[1] - logrus = input("Enter the UID matching the key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") -else: - keyfile = input("Enter the path and filename to save the secret key to: ") - logrus = input("Enter the UID matching the key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") - -if homedir.startswith("~"): - if os.path.exists(os.path.expanduser(homedir)) is True: - c.home_dir = os.path.expanduser(homedir) - else: - pass -elif os.path.exists(homedir) is True: - c.home_dir = homedir -else: - pass - -try: - result = c.key_export_minimal(pattern=logrus) -except: - result = c.key_export_minimal(pattern=None) - -if result is not None: - with open(keyfile, "wb") as f: - f.write(result) -else: - pass -@end example - -@node Exporting secret keys -@subsection Exporting secret keys - -Exporting secret keys is, functionally, very similar to exporting -public keys; save for the invocation of @samp{pinentry} via @samp{gpg-agent} in -order to securely enter the key's passphrase and authorise the export. - -The following example exports the secret key to a file which is then -set with the same permissions as the output files created by the -command line secret key export options. - -@example -import gpg -import os -import os.path -import sys - -print(""" -This script exports one or more secret keys. - -The gpg-agent and pinentry are invoked to authorise the export. -""") - -c = gpg.Context(armor=True) - -if len(sys.argv) >= 4: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = sys.argv[3] -elif len(sys.argv) == 3: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = input("Enter the GPG configuration directory path (optional): ") -elif len(sys.argv) == 2: - keyfile = sys.argv[1] - logrus = input("Enter the UID matching the secret key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") -else: - keyfile = input("Enter the path and filename to save the secret key to: ") - logrus = input("Enter the UID matching the secret key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") - -if len(homedir) == 0: - homedir = None -elif homedir.startswith("~"): - userdir = os.path.expanduser(homedir) - if os.path.exists(userdir) is True: - homedir = os.path.realpath(userdir) - else: - homedir = None -else: - homedir = os.path.realpath(homedir) - -if os.path.exists(homedir) is False: - homedir = None -else: - if os.path.isdir(homedir) is False: - homedir = None - else: - pass - -if homedir is not None: - c.home_dir = homedir -else: - pass - -try: - result = c.key_export_secret(pattern=logrus) -except: - result = c.key_export_secret(pattern=None) - -if result is not None: - with open(keyfile, "wb") as f: - f.write(result) - os.chmod(keyfile, 0o600) -else: - pass -@end example - -Alternatively the approach of the following script can be used. This -longer example saves the exported secret key(s) in files in the GnuPG -home directory, in addition to setting the file permissions as only -readable and writable by the user. It also exports the secret key(s) -twice in order to output both GPG binary (@samp{.gpg}) and ASCII armoured -(@samp{.asc}) files. - -@example -import gpg -import os -import os.path -import subprocess -import sys - -print(""" -This script exports one or more secret keys as both ASCII armored and binary -file formats, saved in files within the user's GPG home directory. - -The gpg-agent and pinentry are invoked to authorise the export. -""") - -if sys.platform == "win32": - gpgconfcmd = "gpgconf.exe --list-dirs homedir" -else: - gpgconfcmd = "gpgconf --list-dirs homedir" - -a = gpg.Context(armor=True) -b = gpg.Context() -c = gpg.Context() - -if len(sys.argv) >= 4: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = sys.argv[3] -elif len(sys.argv) == 3: - keyfile = sys.argv[1] - logrus = sys.argv[2] - homedir = input("Enter the GPG configuration directory path (optional): ") -elif len(sys.argv) == 2: - keyfile = sys.argv[1] - logrus = input("Enter the UID matching the secret key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") -else: - keyfile = input("Enter the filename to save the secret key to: ") - logrus = input("Enter the UID matching the secret key(s) to export: ") - homedir = input("Enter the GPG configuration directory path (optional): ") - -if len(homedir) == 0: - homedir = None -elif homedir.startswith("~"): - userdir = os.path.expanduser(homedir) - if os.path.exists(userdir) is True: - homedir = os.path.realpath(userdir) - else: - homedir = None -else: - homedir = os.path.realpath(homedir) - -if os.path.exists(homedir) is False: - homedir = None -else: - if os.path.isdir(homedir) is False: - homedir = None - else: - pass - -if homedir is not None: - c.home_dir = homedir -else: - pass - -if c.home_dir is not None: - if c.home_dir.endswith("/"): - gpgfile = "@{0@}@{1@}.gpg".format(c.home_dir, keyfile) - ascfile = "@{0@}@{1@}.asc".format(c.home_dir, keyfile) - else: - gpgfile = "@{0@}/@{1@}.gpg".format(c.home_dir, keyfile) - ascfile = "@{0@}/@{1@}.asc".format(c.home_dir, keyfile) -else: - if os.path.exists(os.environ["GNUPGHOME"]) is True: - hd = os.environ["GNUPGHOME"] - else: - try: - hd = subprocess.getoutput(gpgconfcmd) - except: - process = subprocess.Popen(gpgconfcmd.split(), - stdout=subprocess.PIPE) - procom = process.communicate() - if sys.version_info[0] == 2: - hd = procom[0].strip() - else: - hd = procom[0].decode().strip() - gpgfile = "@{0@}/@{1@}.gpg".format(hd, keyfile) - ascfile = "@{0@}/@{1@}.asc".format(hd, keyfile) - -try: - a_result = a.key_export_secret(pattern=logrus) - b_result = b.key_export_secret(pattern=logrus) -except: - a_result = a.key_export_secret(pattern=None) - b_result = b.key_export_secret(pattern=None) - -if a_result is not None: - with open(ascfile, "wb") as f: - f.write(a_result) - os.chmod(ascfile, 0o600) -else: - pass - -if b_result is not None: - with open(gpgfile, "wb") as f: - f.write(b_result) - os.chmod(gpgfile, 0o600) -else: - pass -@end example - -@node Sending public keys to the SKS Keyservers -@subsection Sending public keys to the SKS Keyservers - -As with the previous section on importing keys, the @samp{hkp4py} module -adds another option with exporting keys in order to send them to the -public keyservers. - -The following example demonstrates how this may be done. - -@example -import gpg -import hkp4py -import os.path -import sys - -print(""" -This script sends one or more public keys to the SKS keyservers and is -essentially a slight variation on the export-key.py script. -""") - -c = gpg.Context(armor=True) -server = hkp4py.KeyServer("hkps://hkps.pool.sks-keyservers.net") - -if len(sys.argv) > 2: - logrus = " ".join(sys.argv[1:]) -elif len(sys.argv) == 2: - logrus = sys.argv[1] -else: - logrus = input("Enter the UID matching the key(s) to send: ") - -if len(logrus) > 0: - try: - export_result = c.key_export(pattern=logrus) - except Exception as e: - print(e) - export_result = None -else: - export_result = c.key_export(pattern=None) - -if export_result is not None: - try: - try: - send_result = server.add(export_result) - except: - send_result = server.add(export_result.decode()) - if send_result is not None: - print(send_result) - else: - pass - except Exception as e: - print(e) -else: - pass -@end example - -An expanded version of this script with additional functions for -specifying an alternative homedir location is in the examples -directory as @samp{send-key-to-keyserver.py}. - -The @samp{hkp4py} module appears to handle both string and byte literal text -data equally well, but the GPGME bindings deal primarily with byte -literal data only and so this script sends in that format first, then -tries the string literal form. - -@node Basic Functions -@chapter Basic Functions - -The most frequently called features of any cryptographic library will -be the most fundamental tasks for encryption software. In this -section we will look at how to programmatically encrypt data, decrypt -it, sign it and verify signatures. - -@menu -* Encryption:: -* Decryption:: -* Signing text and files:: -* Signature verification:: -@end menu - -@node Encryption -@section Encryption - -Encrypting is very straight forward. In the first example below the -message, @samp{text}, is encrypted to a single recipient's key. In the -second example the message will be encrypted to multiple recipients. - -@menu -* Encrypting to one key:: -* Encrypting to multiple keys:: -@end menu - -@node Encrypting to one key -@subsection Encrypting to one key - -Once the the Context is set the main issues with encrypting data is -essentially reduced to key selection and the keyword arguments -specified in the @samp{gpg.Context().encrypt()} method. - -Those keyword arguments are: @samp{recipients}, a list of keys encrypted to -(covered in greater detail in the following section); @samp{sign}, whether -or not to sign the plaintext data, see subsequent sections on signing -and verifying signatures below (defaults to @samp{True}); @samp{sink}, to write -results or partial results to a secure sink instead of returning it -(defaults to @samp{None}); @samp{passphrase}, only used when utilising symmetric -encryption (defaults to @samp{None}); @samp{always_trust}, used to override the -trust model settings for recipient keys (defaults to @samp{False}); -@samp{add_encrypt_to}, utilises any preconfigured @samp{encrypt-to} or -@samp{default-key} settings in the user's @samp{gpg.conf} file (defaults to -@samp{False}); @samp{prepare}, prepare for encryption (defaults to @samp{False}); -@samp{expect_sign}, prepare for signing (defaults to @samp{False}); @samp{compress}, -compresses the plaintext prior to encryption (defaults to @samp{True}). - -@example -import gpg - -a_key = "0x12345678DEADBEEF" -text = b"""Some text to test with. - -Since the text in this case must be bytes, it is most likely that -the input form will be a separate file which is opened with "rb" -as this is the simplest method of obtaining the correct data format. -""" - -c = gpg.Context(armor=True) -rkey = list(c.keylist(pattern=a_key, secret=False)) -ciphertext, result, sign_result = c.encrypt(text, recipients=rkey, sign=False) - -with open("secret_plans.txt.asc", "wb") as afile: - afile.write(ciphertext) -@end example - -Though this is even more likely to be used like this; with the -plaintext input read from a file, the recipient keys used for -encryption regardless of key trust status and the encrypted output -also encrypted to any preconfigured keys set in the @samp{gpg.conf} file: - -@example -import gpg - -a_key = "0x12345678DEADBEEF" - -with open("secret_plans.txt", "rb") as afile: - text = afile.read() - -c = gpg.Context(armor=True) -rkey = list(c.keylist(pattern=a_key, secret=False)) -ciphertext, result, sign_result = c.encrypt(text, recipients=rkey, sign=True, - always_trust=True, - add_encrypt_to=True) - -with open("secret_plans.txt.asc", "wb") as afile: - afile.write(ciphertext) -@end example - -If the @samp{recipients} paramater is empty then the plaintext is encrypted -symmetrically. If no @samp{passphrase} is supplied as a parameter or via a -callback registered with the @samp{Context()} then an out-of-band prompt -for the passphrase via pinentry will be invoked. - -@node Encrypting to multiple keys -@subsection Encrypting to multiple keys - -Encrypting to multiple keys essentially just expands upon the key -selection process and the recipients from the previous examples. - -The following example encrypts a message (@samp{text}) to everyone with an -email address on the @samp{gnupg.org} domain,@footnote{You probably don't really want to do this. Searching the -keyservers for "gnupg.org" produces over 400 results, the majority of -which aren't actually at the gnupg.org domain, but just included a -comment regarding the project in their key somewhere.} but does @emph{not} encrypt -to a default key or other key which is configured to normally encrypt -to. - -@example -import gpg - -text = b"""Oh look, another test message. - -The same rules apply as with the previous example and more likely -than not, the message will actually be drawn from reading the -contents of a file or, maybe, from entering data at an input() -prompt. - -Since the text in this case must be bytes, it is most likely that -the input form will be a separate file which is opened with "rb" -as this is the simplest method of obtaining the correct data -format. -""" - -c = gpg.Context(armor=True) -rpattern = list(c.keylist(pattern="@@gnupg.org", secret=False)) -logrus = [] - -for i in range(len(rpattern)): - if rpattern[i].can_encrypt == 1: - logrus.append(rpattern[i]) - -ciphertext, result, sign_result = c.encrypt(text, recipients=logrus, - sign=False, always_trust=True) - -with open("secret_plans.txt.asc", "wb") as afile: - afile.write(ciphertext) -@end example - -All it would take to change the above example to sign the message -and also encrypt the message to any configured default keys would -be to change the @samp{c.encrypt} line to this: - -@example -ciphertext, result, sign_result = c.encrypt(text, recipients=logrus, - always_trust=True, - add_encrypt_to=True) -@end example - -The only keyword arguments requiring modification are those for which -the default values are changing. The default value of @samp{sign} is -@samp{True}, the default of @samp{always_trust} is @samp{False}, the default of -@samp{add_encrypt_to} is @samp{False}. - -If @samp{always_trust} is not set to @samp{True} and any of the recipient keys -are not trusted (e.g. not signed or locally signed) then the -encryption will raise an error. It is possible to mitigate this -somewhat with something more like this: - -@example -import gpg - -with open("secret_plans.txt.asc", "rb") as afile: - text = afile.read() - -c = gpg.Context(armor=True) -rpattern = list(c.keylist(pattern="@@gnupg.org", secret=False)) -logrus = [] - -for i in range(len(rpattern)): - if rpattern[i].can_encrypt == 1: - logrus.append(rpattern[i]) - - try: - ciphertext, result, sign_result = c.encrypt(text, recipients=logrus, - add_encrypt_to=True) - except gpg.errors.InvalidRecipients as e: - for i in range(len(e.recipients)): - for n in range(len(logrus)): - if logrus[n].fpr == e.recipients[i].fpr: - logrus.remove(logrus[n]) - else: - pass - try: - ciphertext, result, sign_result = c.encrypt(text, - recipients=logrus, - add_encrypt_to=True) - with open("secret_plans.txt.asc", "wb") as afile: - afile.write(ciphertext) - except: - pass -@end example - -This will attempt to encrypt to all the keys searched for, then remove -invalid recipients if it fails and try again. - -@node Decryption -@section Decryption - -Decrypting something encrypted to a key in one's secret keyring is -fairly straight forward. - -In this example code, however, preconfiguring either @samp{gpg.Context()} -or @samp{gpg.core.Context()} as @samp{c} is unnecessary because there is no need -to modify the Context prior to conducting the decryption and since the -Context is only used once, setting it to @samp{c} simply adds lines for no -gain. - -@example -import gpg - -ciphertext = input("Enter path and filename of encrypted file: ") -newfile = input("Enter path and filename of file to save decrypted data to: ") - -with open(ciphertext, "rb") as cfile: - try: - plaintext, result, verify_result = gpg.Context().decrypt(cfile) - except gpg.errors.GPGMEError as e: - plaintext = None - print(e) - -if plaintext is not None: - with open(newfile, "wb") as nfile: - nfile.write(plaintext) - else: - pass -@end example - -The data available in @samp{plaintext} in this example is the decrypted -content as a byte object, the recipient key IDs and algorithms in -@samp{result} and the results of verifying any signatures of the data in -@samp{verify_result}. - -@node Signing text and files -@section Signing text and files - -The following sections demonstrate how to specify keys to sign with. - -@menu -* Signing key selection:: -* Normal or default signing messages or files:: -* Detached signing messages and files:: -* Clearsigning messages or text:: -@end menu - -@node Signing key selection -@subsection Signing key selection - -By default GPGME and the Python bindings will use the default key -configured for the user invoking the GPGME API. If there is no -default key specified and there is more than one secret key available -it may be necessary to specify the key or keys with which to sign -messages and files. - -@example -import gpg - -logrus = input("Enter the email address or string to match signing keys to: ") -hancock = gpg.Context().keylist(pattern=logrus, secret=True) -sig_src = list(hancock) -@end example - -The signing examples in the following sections include the explicitly -designated @samp{signers} parameter in two of the five examples; once where -the resulting signature would be ASCII armoured and once where it -would not be armoured. - -While it would be possible to enter a key ID or fingerprint here to -match a specific key, it is not possible to enter two fingerprints and -match two keys since the patten expects a string, bytes or None and -not a list. A string with two fingerprints won't match any single -key. - -@node Normal or default signing messages or files -@subsection Normal or default signing messages or files - -The normal or default signing process is essentially the same as is -most often invoked when also encrypting a message or file. So when -the encryption component is not utilised, the result is to produce an -encoded and signed output which may or may not be ASCII armoured and -which may or may not also be compressed. - -By default compression will be used unless GnuPG detects that the -plaintext is already compressed. ASCII armouring will be determined -according to the value of @samp{gpg.Context().armor}. - -The compression algorithm is selected in much the same way as the -symmetric encryption algorithm or the hash digest algorithm is when -multiple keys are involved; from the preferences saved into the key -itself or by comparison with the preferences with all other keys -involved. - -@example -import gpg - -text0 = """Declaration of ... something. - -""" -text = text0.encode() - -c = gpg.Context(armor=True, signers=sig_src) -signed_data, result = c.sign(text, mode=gpg.constants.sig.mode.NORMAL) - -with open("/path/to/statement.txt.asc", "w") as afile: - afile.write(signed_data.decode()) -@end example - -Though everything in this example is accurate, it is more likely that -reading the input data from another file and writing the result to a -new file will be performed more like the way it is done in the next -example. Even if the output format is ASCII armoured. - -@example -import gpg - -with open("/path/to/statement.txt", "rb") as tfile: - text = tfile.read() - -c = gpg.Context() -signed_data, result = c.sign(text, mode=gpg.constants.sig.mode.NORMAL) - -with open("/path/to/statement.txt.sig", "wb") as afile: - afile.write(signed_data) -@end example - -@node Detached signing messages and files -@subsection Detached signing messages and files - -Detached signatures will often be needed in programmatic uses of -GPGME, either for signing files (e.g. tarballs of code releases) or as -a component of message signing (e.g. PGP/MIME encoded email). - -@example -import gpg - -text0 = """Declaration of ... something. - -""" -text = text0.encode() - -c = gpg.Context(armor=True) -signed_data, result = c.sign(text, mode=gpg.constants.sig.mode.DETACH) - -with open("/path/to/statement.txt.asc", "w") as afile: - afile.write(signed_data.decode()) -@end example - -As with normal signatures, detached signatures are best handled as -byte literals, even when the output is ASCII armoured. - -@example -import gpg - -with open("/path/to/statement.txt", "rb") as tfile: - text = tfile.read() - -c = gpg.Context(signers=sig_src) -signed_data, result = c.sign(text, mode=gpg.constants.sig.mode.DETACH) - -with open("/path/to/statement.txt.sig", "wb") as afile: - afile.write(signed_data) -@end example - -@node Clearsigning messages or text -@subsection Clearsigning messages or text - -Though PGP/in-line messages are no longer encouraged in favour of -PGP/MIME, there is still sometimes value in utilising in-line -signatures. This is where clear-signed messages or text is of value. - -@example -import gpg - -text0 = """Declaration of ... something. - -""" -text = text0.encode() - -c = gpg.Context() -signed_data, result = c.sign(text, mode=gpg.constants.sig.mode.CLEAR) - -with open("/path/to/statement.txt.asc", "w") as afile: - afile.write(signed_data.decode()) -@end example - -In spite of the appearance of a clear-signed message, the data handled -by GPGME in signing it must still be byte literals. - -@example -import gpg - -with open("/path/to/statement.txt", "rb") as tfile: - text = tfile.read() - -c = gpg.Context() -signed_data, result = c.sign(text, mode=gpg.constants.sig.mode.CLEAR) - -with open("/path/to/statement.txt.asc", "wb") as afile: - afile.write(signed_data) -@end example - -@node Signature verification -@section Signature verification - -Essentially there are two principal methods of verification of a -signature. The first of these is for use with the normal or default -signing method and for clear-signed messages. The second is for use -with files and data with detached signatures. - -The following example is intended for use with the default signing -method where the file was not ASCII armoured: - -@example -import gpg -import time - -filename = "statement.txt" -gpg_file = "statement.txt.gpg" - -c = gpg.Context() - -try: - data, result = c.verify(open(gpg_file)) - verified = True -except gpg.errors.BadSignatures as e: - verified = False - print(e) - -if verified is True: - for i in range(len(result.signatures)): - sign = result.signatures[i] - print("""Good signature from: -@{0@} -with key @{1@} -made at @{2@} -""".format(c.get_key(sign.fpr).uids[0].uid, sign.fpr, - time.ctime(sign.timestamp))) -else: - pass -@end example - -Whereas this next example, which is almost identical would work with -normal ASCII armoured files and with clear-signed files: - -@example -import gpg -import time - -filename = "statement.txt" -asc_file = "statement.txt.asc" - -c = gpg.Context() - -try: - data, result = c.verify(open(asc_file)) - verified = True -except gpg.errors.BadSignatures as e: - verified = False - print(e) - -if verified is True: - for i in range(len(result.signatures)): - sign = result.signatures[i] - print("""Good signature from: -@{0@} -with key @{1@} -made at @{2@} -""".format(c.get_key(sign.fpr).uids[0].uid, sign.fpr, - time.ctime(sign.timestamp))) -else: - pass -@end example - -In both of the previous examples it is also possible to compare the -original data that was signed against the signed data in @samp{data} to see -if it matches with something like this: - -@example -with open(filename, "rb") as afile: - text = afile.read() - -if text == data: - print("Good signature.") -else: - pass -@end example - -The following two examples, however, deal with detached signatures. -With his method of verification the data that was signed does not get -returned since it is already being explicitly referenced in the first -argument of @samp{c.verify}. So @samp{data} is @samp{None} and only the information -in @samp{result} is available. - -@example -import gpg -import time - -filename = "statement.txt" -sig_file = "statement.txt.sig" - -c = gpg.Context() - -try: - data, result = c.verify(open(filename), open(sig_file)) - verified = True -except gpg.errors.BadSignatures as e: - verified = False - print(e) - -if verified is True: - for i in range(len(result.signatures)): - sign = result.signatures[i] - print("""Good signature from: -@{0@} -with key @{1@} -made at @{2@} -""".format(c.get_key(sign.fpr).uids[0].uid, sign.fpr, - time.ctime(sign.timestamp))) -else: - pass -@end example - -@example -import gpg -import time - -filename = "statement.txt" -asc_file = "statement.txt.asc" - -c = gpg.Context() - -try: - data, result = c.verify(open(filename), open(asc_file)) - verified = True -except gpg.errors.BadSignatures as e: - verified = False - print(e) - -if verified is True: - for i in range(len(result.signatures)): - sign = result.signatures[i] - print("""Good signature from: -@{0@} -with key @{1@} -made at @{2@} -""".format(c.get_key(sign.fpr).uids[0].uid, sign.fpr, - time.ctime(sign.timestamp))) -else: - pass -@end example - -@node Creating keys and subkeys -@chapter Creating keys and subkeys - -The one thing, aside from GnuPG itself, that GPGME depends on, of -course, is the keys themselves. So it is necessary to be able to -generate them and modify them by adding subkeys, revoking or disabling -them, sometimes deleting them and doing the same for user IDs. - -In the following examples a key will be created for the world's -greatest secret agent, Danger Mouse. Since Danger Mouse is a secret -agent he needs to be able to protect information to @samp{SECRET} level -clearance, so his keys will be 3072-bit keys. - -The pre-configured @samp{gpg.conf} file which sets cipher, digest and other -preferences contains the following configuration parameters: - -@example -expert -allow-freeform-uid -allow-secret-key-import -trust-model tofu+pgp -tofu-default-policy unknown -enable-large-rsa -enable-dsa2 -cert-digest-algo SHA512 -default-preference-list TWOFISH CAMELLIA256 AES256 CAMELLIA192 AES192 CAMELLIA128 AES BLOWFISH IDEA CAST5 3DES SHA512 SHA384 SHA256 SHA224 RIPEMD160 SHA1 ZLIB BZIP2 ZIP Uncompressed -personal-cipher-preferences TWOFISH CAMELLIA256 AES256 CAMELLIA192 AES192 CAMELLIA128 AES BLOWFISH IDEA CAST5 3DES -personal-digest-preferences SHA512 SHA384 SHA256 SHA224 RIPEMD160 SHA1 -personal-compress-preferences ZLIB BZIP2 ZIP Uncompressed -@end example - -@menu -* Primary key:: -* Subkeys:: -* User IDs:: -* Key certification:: -@end menu - -@node Primary key -@section Primary key - -Generating a primary key uses the @samp{create_key} method in a Context. -It contains multiple arguments and keyword arguments, including: -@samp{userid}, @samp{algorithm}, @samp{expires_in}, @samp{expires}, @samp{sign}, @samp{encrypt}, -@samp{certify}, @samp{authenticate}, @samp{passphrase} and @samp{force}. The defaults for -all of those except @samp{userid}, @samp{algorithm}, @samp{expires_in}, @samp{expires} and -@samp{passphrase} is @samp{False}. The defaults for @samp{algorithm} and -@samp{passphrase} is @samp{None}. The default for @samp{expires_in} is @samp{0}. The -default for @samp{expires} is @samp{True}. There is no default for @samp{userid}. - -If @samp{passphrase} is left as @samp{None} then the key will not be generated -with a passphrase, if @samp{passphrase} is set to a string then that will -be the passphrase and if @samp{passphrase} is set to @samp{True} then gpg-agent -will launch pinentry to prompt for a passphrase. For the sake of -convenience, these examples will keep @samp{passphrase} set to @samp{None}. - -@example -import gpg - -c = gpg.Context() - -c.home_dir = "~/.gnupg-dm" -userid = "Danger Mouse " - -dmkey = c.create_key(userid, algorithm="rsa3072", expires_in=31536000, - sign=True, certify=True) -@end example - -One thing to note here is the use of setting the @samp{c.home_dir} -parameter. This enables generating the key or keys in a different -location. In this case to keep the new key data created for this -example in a separate location rather than adding it to existing and -active key store data. As with the default directory, @samp{~/.gnupg}, any -temporary or separate directory needs the permissions set to only -permit access by the directory owner. On posix systems this means -setting the directory permissions to 700. - -The @samp{temp-homedir-config.py} script in the HOWTO examples directory -will create an alternative homedir with these configuration options -already set and the correct directory and file permissions. - -The successful generation of the key can be confirmed via the returned -@samp{GenkeyResult} object, which includes the following data: - -@example -print(""" - Fingerprint: @{0@} - Primary Key: @{1@} - Public Key: @{2@} - Secret Key: @{3@} - Sub Key: @{4@} -User IDs: @{5@} -""".format(dmkey.fpr, dmkey.primary, dmkey.pubkey, dmkey.seckey, dmkey.sub, - dmkey.uid)) -@end example - -Alternatively the information can be confirmed using the command line -program: - -@example -bash-4.4$ gpg --homedir ~/.gnupg-dm -K -~/.gnupg-dm/pubring.kbx ----------------------- -sec rsa3072 2018-03-15 [SC] [expires: 2019-03-15] - 177B7C25DB99745EE2EE13ED026D2F19E99E63AA -uid [ultimate] Danger Mouse - -bash-4.4$ -@end example - -As with generating keys manually, to preconfigure expanded preferences -for the cipher, digest and compression algorithms, the @samp{gpg.conf} file -must contain those details in the home directory in which the new key -is being generated. I used a cut down version of my own @samp{gpg.conf} -file in order to be able to generate this: - -@example -bash-4.4$ gpg --homedir ~/.gnupg-dm --edit-key 177B7C25DB99745EE2EE13ED026D2F19E99E63AA showpref quit -Secret key is available. - -sec rsa3072/026D2F19E99E63AA - created: 2018-03-15 expires: 2019-03-15 usage: SC - trust: ultimate validity: ultimate -[ultimate] (1). Danger Mouse - -[ultimate] (1). Danger Mouse - Cipher: TWOFISH, CAMELLIA256, AES256, CAMELLIA192, AES192, CAMELLIA128, AES, BLOWFISH, IDEA, CAST5, 3DES - Digest: SHA512, SHA384, SHA256, SHA224, RIPEMD160, SHA1 - Compression: ZLIB, BZIP2, ZIP, Uncompressed - Features: MDC, Keyserver no-modify - -bash-4.4$ -@end example - -@node Subkeys -@section Subkeys - -Adding subkeys to a primary key is fairly similar to creating the -primary key with the @samp{create_subkey} method. Most of the arguments -are the same, but not quite all. Instead of the @samp{userid} argument -there is now a @samp{key} argument for selecting which primary key to add -the subkey to. - -In the following example an encryption subkey will be added to the -primary key. Since Danger Mouse is a security conscious secret agent, -this subkey will only be valid for about six months, half the length -of the primary key. - -@example -import gpg - -c = gpg.Context() -c.home_dir = "~/.gnupg-dm" - -key = c.get_key(dmkey.fpr, secret=True) -dmsub = c.create_subkey(key, algorithm="rsa3072", expires_in=15768000, - encrypt=True) -@end example - -As with the primary key, the results here can be checked with: - -@example -print(""" - Fingerprint: @{0@} - Primary Key: @{1@} - Public Key: @{2@} - Secret Key: @{3@} - Sub Key: @{4@} -User IDs: @{5@} -""".format(dmsub.fpr, dmsub.primary, dmsub.pubkey, dmsub.seckey, dmsub.sub, - dmsub.uid)) -@end example - -As well as on the command line with: - -@example -bash-4.4$ gpg --homedir ~/.gnupg-dm -K -~/.gnupg-dm/pubring.kbx ----------------------- -sec rsa3072 2018-03-15 [SC] [expires: 2019-03-15] - 177B7C25DB99745EE2EE13ED026D2F19E99E63AA -uid [ultimate] Danger Mouse -ssb rsa3072 2018-03-15 [E] [expires: 2018-09-13] - -bash-4.4$ -@end example - -@node User IDs -@section User IDs - -@menu -* Adding User IDs:: -* Revokinging User IDs:: -@end menu - -@node Adding User IDs -@subsection Adding User IDs - -By comparison to creating primary keys and subkeys, adding a new user -ID to an existing key is much simpler. The method used to do this is -@samp{key_add_uid} and the only arguments it takes are for the @samp{key} and -the new @samp{uid}. - -@example -import gpg - -c = gpg.Context() -c.home_dir = "~/.gnupg-dm" - -dmfpr = "177B7C25DB99745EE2EE13ED026D2F19E99E63AA" -key = c.get_key(dmfpr, secret=True) -uid = "Danger Mouse " - -c.key_add_uid(key, uid) -@end example - -Unsurprisingly the result of this is: - -@example -bash-4.4$ gpg --homedir ~/.gnupg-dm -K -~/.gnupg-dm/pubring.kbx ----------------------- -sec rsa3072 2018-03-15 [SC] [expires: 2019-03-15] - 177B7C25DB99745EE2EE13ED026D2F19E99E63AA -uid [ultimate] Danger Mouse -uid [ultimate] Danger Mouse -ssb rsa3072 2018-03-15 [E] [expires: 2018-09-13] - -bash-4.4$ -@end example - -@node Revokinging User IDs -@subsection Revokinging User IDs - -Revoking a user ID is a fairly similar process, except that it uses -the @samp{key_revoke_uid} method. - -@example -import gpg - -c = gpg.Context() -c.home_dir = "~/.gnupg-dm" - -dmfpr = "177B7C25DB99745EE2EE13ED026D2F19E99E63AA" -key = c.get_key(dmfpr, secret=True) -uid = "Danger Mouse " - -c.key_revoke_uid(key, uid) -@end example - -@node Key certification -@section Key certification - -Since key certification is more frequently referred to as key signing, -the method used to perform this function is @samp{key_sign}. - -The @samp{key_sign} method takes four arguments: @samp{key}, @samp{uids}, -@samp{expires_in} and @samp{local}. The default value of @samp{uids} is @samp{None} and -which results in all user IDs being selected. The default value of -both @samp{expires_in} and @samp{local} is @samp{False}; which results in the -signature never expiring and being able to be exported. - -The @samp{key} is the key being signed rather than the key doing the -signing. To change the key doing the signing refer to the signing key -selection above for signing messages and files. - -If the @samp{uids} value is not @samp{None} then it must either be a string to -match a single user ID or a list of strings to match multiple user -IDs. In this case the matching of those strings must be precise and -it is case sensitive. - -To sign Danger Mouse's key for just the initial user ID with a -signature which will last a little over a month, do this: - -@example -import gpg - -c = gpg.Context() -uid = "Danger Mouse " - -dmfpr = "177B7C25DB99745EE2EE13ED026D2F19E99E63AA" -key = c.get_key(dmfpr, secret=True) -c.key_sign(key, uids=uid, expires_in=2764800) -@end example - -@node Advanced or Experimental Use Cases -@chapter Advanced or Experimental Use Cases - -@menu -* C plus Python plus SWIG plus Cython:: -@end menu - -@node C plus Python plus SWIG plus Cython -@section C plus Python plus SWIG plus Cython - -In spite of the apparent incongruence of using Python bindings to a C -interface only to generate more C from the Python; it is in fact quite -possible to use the GPGME bindings with @uref{http://docs.cython.org/en/latest/index.html, Cython}. Though in many cases -the benefits may not be obvious since the most computationally -intensive work never leaves the level of the C code with which GPGME -itself is interacting with. - -Nevertheless, there are some situations where the benefits are -demonstrable. One of the better and easier examples being the one of -the early examples in this HOWTO, the @ref{Counting keys, , key counting} code. Running that -example as an executable Python script, @samp{keycount.py} (available in -the @samp{examples/howto/} directory), will take a noticable amount of time -to run on most systems where the public keybox or keyring contains a -few thousand public keys. - -Earlier in the evening, prior to starting this section, I ran that -script on my laptop; as I tend to do periodically and timed it using -@samp{time} utility, with the following results: - -@example -bash-4.4$ time keycount.py - -Number of secret keys: 23 -Number of public keys: 12112 - - -real 11m52.945s -user 0m0.913s -sys 0m0.752s - -bash-4.4$ -@end example - -Sometime after that I imported another key and followed it with a -little test of Cython. This test was kept fairly basic, essentially -lifting the material from the @uref{http://docs.cython.org/en/latest/src/tutorial/cython_tutorial.html, Cython Basic Tutorial} to demonstrate -compiling Python code to C. The first step was to take the example -key counting code quoted previously, essentially from the importing of -the @samp{gpg} module to the end of the script: - -@example -import gpg - -c = gpg.Context() -seckeys = c.keylist(pattern=None, secret=True) -pubkeys = c.keylist(pattern=None, secret=False) - -seclist = list(seckeys) -secnum = len(seclist) - -publist = list(pubkeys) -pubnum = len(publist) - -print(""" - Number of secret keys: @{0@} - Number of public keys: @{1@} - -""".format(secnum, pubnum)) -@end example - -Save that into a file called @samp{keycount.pyx} and then create a -@samp{setup.py} file which contains this: - -@example -from distutils.core import setup -from Cython.Build import cythonize - -setup( - ext_modules = cythonize("keycount.pyx") -) -@end example - -Compile it: - -@example -bash-4.4$ python setup.py build_ext --inplace -bash-4.4$ -@end example - -Then run it in a similar manner to @samp{keycount.py}: - -@example -bash-4.4$ time python3.7 -c "import keycount" - -Number of secret keys: 23 -Number of public keys: 12113 - - -real 6m47.905s -user 0m0.785s -sys 0m0.331s - -bash-4.4$ -@end example - -Cython turned @samp{keycount.pyx} into an 81KB @samp{keycount.o} file in the -@samp{build/} directory, a 24KB @samp{keycount.cpython-37m-darwin.so} file to be -imported into Python 3.7 and a 113KB @samp{keycount.c} generated C source -code file of nearly three thousand lines. Quite a bit bigger than the -314 bytes of the @samp{keycount.pyx} file or the full 1,452 bytes of the -full executable @samp{keycount.py} example script. - -On the other hand it ran in nearly half the time; taking 6 minutes and -47.905 seconds to run. As opposed to the 11 minutes and 52.945 seconds -which the CPython script alone took. - -The @samp{keycount.pyx} and @samp{setup.py} files used to generate this example -have been added to the @samp{examples/howto/advanced/cython/} directory -The example versions include some additional options to annotate the -existing code and to detect Cython's use. The latter comes from the -@uref{http://docs.cython.org/en/latest/src/tutorial/pure.html#magic-attributes-within-the-pxd, Magic Attributes} section of the Cython documentation. - -@node Miscellaneous extras and work-arounds -@chapter Miscellaneous extras and work-arounds - -Most of the things in the following sections are here simply because -there was no better place to put them, even though some are only -peripherally related to the GPGME Python bindings. Some are also -workarounds for functions not integrated with GPGME as yet. This is -especially true of the first of these, dealing with @ref{Group lines, , group lines}. - -@menu -* Group lines:: -* Keyserver access for Python:: -@end menu - -@node Group lines -@section Group lines - -There is not yet an easy way to access groups configured in the -gpg.conf file from within GPGME. As a consequence these central -groupings of keys cannot be shared amongst multiple programs, such as -MUAs readily. - -The following code, however, provides a work-around for obtaining this -information in Python. - -@example -import subprocess -import sys - -if sys.platform == "win32": - gpgconfcmd = "gpgconf.exe --list-options gpg" -else: - gpgconfcmd = "gpgconf --list-options gpg" - -try: - lines = subprocess.getoutput(gpgconfcmd).splitlines() -except: - process = subprocess.Popen(gpgconfcmd.split(), stdout=subprocess.PIPE) - procom = process.communicate() - if sys.version_info[0] == 2: - lines = procom[0].splitlines() - else: - lines = procom[0].decode().splitlines() - -for i in range(len(lines)): - if lines[i].startswith("group") is True: - line = lines[i] - else: - pass - -groups = line.split(":")[-1].replace('"', '').split(',') - -group_lines = [] -group_lists = [] - -for i in range(len(groups)): - group_lines.append(groups[i].split("=")) - group_lists.append(groups[i].split("=")) - -for i in range(len(group_lists)): - group_lists[i][1] = group_lists[i][1].split() -@end example - -The result of that code is that @samp{group_lines} is a list of lists where -@samp{group_lines[i][0]} is the name of the group and @samp{group_lines[i][1]} -is the key IDs of the group as a string. - -The @samp{group_lists} result is very similar in that it is a list of -lists. The first part, @samp{group_lists[i][0]} matches -@samp{group_lines[i][0]} as the name of the group, but @samp{group_lists[i][1]} -is the key IDs of the group as a string. - -A demonstration of using the @samp{groups.py} module is also available in -the form of the executable @samp{mutt-groups.py} script. This second -script reads all the group entries in a user's @samp{gpg.conf} file and -converts them into crypt-hooks suitable for use with the Mutt and -Neomutt mail clients. - -@node Keyserver access for Python -@section Keyserver access for Python - -The @uref{https://github.com/Selfnet/hkp4py, hkp4py} module by Marcel Fest was originally a port of the old -@uref{https://github.com/dgladkov/python-hkp, python-hkp} module from Python 2 to Python 3 and updated to use the -@uref{http://docs.python-requests.org/en/latest/index.html, requests} module instead. It has since been modified to provide -support for Python 2.7 as well and is available via PyPI. - -Since it rewrites the @samp{hkp} protocol prefix as @samp{http} and @samp{hkps} as -@samp{https}, the module is able to be used even with servers which do not -support the full scope of keyserver functions.@footnote{Such as with ProtonMail servers. This also means that -restricted servers which only advertise either HTTP or HTTPS end -points and not HKP or HKPS end points must still be identified as as -HKP or HKPS within the Python Code. The @samp{hkp4py} module will rewrite -these appropriately when the connection is made to the server.} It also works quite -readily when incorporated into a @ref{C plus Python plus SWIG plus Cython, , Cython} generated and compiled version -of any code. - -@menu -* Key import format:: -@end menu - -@node Key import format -@subsection Key import format - -The hkp4py module returns key data via requests as string literals -(@samp{r.text}) instead of byte literals (@samp{r.content}). This means that -the retrurned key data must be encoded to UTF-8 when importing that -key material using a @samp{gpg.Context().key_import()} method. - -For this reason an alternative method has been added to the @samp{search} -function of @samp{hkp4py.KeyServer()} which returns the key in the correct -format as expected by @samp{key_import}. When importing using this module, -it is now possible to import with this: - -@example -for key in keys: - if key.revoked is False: - gpg.Context().key_import(key.key_blob) - else: - pass -@end example - -Without that recent addition it would have been necessary to encode -the contents of each @samp{hkp4py.KeyServer().search()[i].key} in -@samp{hkp4py.KeyServer().search()} before trying to import it. - -An example of this is included in the @ref{Importing keys, , Importing Keys} section of this -HOWTO and the corresponding executable version of that example is -available in the @samp{lang/python/examples/howto} directory as normal; the -executable version is the @samp{import-keys-hkp.py} file. - -@node Copyright and Licensing -@chapter Copyright and Licensing - -@menu -* Copyright:: -* Draft Editions of this HOWTO:: -* License GPL compatible:: -@end menu - -@node Copyright -@section Copyright - -Copyright © The GnuPG Project, 2018. - -Copyright (C) The GnuPG Project, 2018. - -@node Draft Editions of this HOWTO -@section Draft Editions of this HOWTO - -Draft editions of this HOWTO may be periodically available directly -from the author at any of the following URLs: - -@itemize -@item -@uref{https://files.au.adversary.org/crypto/gpgme-python-howto.html, GPGME Python Bindings HOWTO draft (XHTML AWS S3 SSL)} -@item -@uref{http://files.au.adversary.org/crypto/gpgme-python-howto.html, GPGME Python Bindings HOWTO draft (XHTML AWS S3 no SSL)} -@item -@uref{https://files.au.adversary.org/crypto/gpgme-python-howto.texi, GPGME Python Bindings HOWTO draft (Texinfo file AWS S3 SSL)} -@item -@uref{http://files.au.adversary.org/crypto/gpgme-python-howto.texi, GPGME Python Bindings HOWTO draft (Texinfo file AWS S3 no SSL)} -@item -@uref{https://files.au.adversary.org/crypto/gpgme-python-howto.info, GPGME Python Bindings HOWTO draft (Info file AWS S3 SSL)} -@item -@uref{http://files.au.adversary.org/crypto/gpgme-python-howto.info, GPGME Python Bindings HOWTO draft (Info file AWS S3 no SSL)} -@item -@uref{https://files.au.adversary.org/crypto/gpgme-python-howto.xml, GPGME Python Bindings HOWTO draft (Docbook 4.2 AWS S3 SSL)} -@item -@uref{http://files.au.adversary.org/crypto/gpgme-python-howto.xml, GPGME Python Bindings HOWTO draft (Docbook 4.2 AWS S3 no SSL)} -@end itemize - -All of these draft versions are generated from this document via Emacs -@uref{https://orgmode.org/, Org mode} and @uref{https://www.gnu.org/software/texinfo/, GNU Texinfo}. Though it is likely that the specific @uref{https://files.au.adversary.org/crypto/gpgme-python-howto.org, file} -@uref{http://files.au.adversary.org/crypto/gpgme-python-howto.org, version} used will be on the same server with the generated output -formats. - -In addition to these there is a significantly less frequently updated -version as a HTML @uref{https://files.au.adversary.org/crypto/gpgme-python-howto/webhelp/index.html, WebHelp site} (AWS S3 SSL); generated from DITA XML -source files, which can be found in @uref{https://dev.gnupg.org/source/gpgme/browse/ben%252Fhowto-dita/, an alternative branch} of the GPGME -git repository. - -These draft editions are not official documents and the version of -documentation in the master branch or which ships with released -versions is the only official documentation. Nevertheless, these -draft editions may occasionally be of use by providing more accessible -web versions which are updated between releases. They are provided on -the understanding that they may contain errors or may contain content -subject to change prior to an official release. - -@node License GPL compatible -@section License GPL compatible - -This file is free software; as a special exception the author gives -unlimited permission to copy and/or distribute it, with or without -modifications, as long as this notice is preserved. - -This file is distributed in the hope that it will be useful, but -WITHOUT ANY WARRANTY, to the extent permitted by law; without even the -implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR -PURPOSE. - -@bye \ No newline at end of file diff --git a/lang/python/docs/Short_History.org b/lang/python/docs/short-history.org similarity index 100% rename from lang/python/docs/Short_History.org rename to lang/python/docs/short-history.org