What is Libgpg-error ==================== Libgpg-error is a library that defines common error values for all GnuPG components. Among these are GPG, GPGSM, GPGME, GPG-Agent, libgcrypt, Libksba, DirMngr, Pinentry, SmartCard Daemon and more. Meanwhile Libgcrypt also sports functions commonly used by all GnuPG components and which are believed to be generally useful. The main components are - Structured error codes and utility functions. - Replacement functions for stdio stream (estream) to provide a reliable set of printf features on all platforms. For convenience macros are provided to make migration from stdio to estream easier (ie. the prefix "es_") - Generic Mutex implementation for all platforms using an ABI independent of the underlying implementation. - A lean gettext and iconv implementation for Windows. - Log functions - Option parser - BAse-64 encoder and decoder. More components will be added over time. Most functions are prefixed with "gpgrt" (GnuPG Run Time) instead of "gpg_err" to indicate the long term plan to rename this library to gpgrt. Libgpg-error is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. See the file COPYING.LIB for copyright and warranty information. See the file AUTHORS for a list of authors and important mail addresses. However, some files (for example src/mkerrnos.awk) used in the build process of the library and the manual are covered by a different license. Please see the header of these files and the file COPYING for copyright and warranty information on these files. A special exception in the copyright license of these files makes sure that the output in the build process, which is used in libgpg-error, is not affected by the GPL. Installation ============ Please read the file INSTALL! Here is a quick summary: 1) Check that you have unmodified sources. You can find instructions how to verify the sources below. Don't skip this - it is an important step! 2) Unpack the archive. With GNU tar you can do it this way: "tar xjvf libgpg-error-x.y.tar.bz2" 3) "cd libgpg-error-x.y" 4) "./configure" 5) "make" 6) "make install" How to Verify the Source ======================== In order to check that the version of libgpg-error which you are going to install is an original and unmodified copy of the original, you can do it in one of the following ways: a) If you already have a trusted version of GnuPG installed, you can simply check the supplied signature: $ gpg --verify libgpg-error-x.y.tar.bz2.sig libgpg-error-x.y.tar.bz2 This checks that the detached signature libgpg-error-x.y.tar.bz2.sig is indeed a signature of libgpg-error-x.y.tar.bz2. Make sure that the signature has been created by a trusted keys. Please note that you have to use an old version of GnuPG to do all this stuff. *Never* use the version which was built using the library you are trying to verify! b) If you don't have any a trusted version of GnuPG, you can attempt to verify the SHA1 checksum, using a trusted version of the sha1sum program: $ sha1sum libgpg-error-x.y.tar.bz2 This should yield an output _similar_ to this: 610064e5b77700f5771c8fde2691c4365e1ca100 libgpg-error-x.y.tar.bz2 Now check that this checksum is _exactly_ the same as the one published via the announcement list and probably via Usenet. Hints ===== To build for Windows you you may use the convenience command: ./autogen.sh --build-w32 which runs configure with suitable options. There is also basic support for building a 64 bit Windows version: ./autogen.sh --build-w64 Cross-Compiling =============== Libgpg-error needs to figure out some platform specific properties. These are used to build the platform specific gpg-error.h file. The detection is done during build time but can't be done when cross-compiling. Thus if you run into an error during building you need to figure out these values. You may use these commands: build="$(build-aux/config.guess)" ./configure --prefix=TARGETDIR --host=TARGET --build=$build cd src make gen-posix-lock-obj scp gen-posix-lock-obj TARGET: ssh TARGET ./gen-posix-lock-obj >tmp.h mv tmp.h "syscfg/$(awk 'NR==1 {print $2}' tmp.h)" If you are using a VPATH build adjust accordingly. If this all works for you (make sure to run the test programs on the target platform), please send the generated file to the gnupg-devel mailing list so that we can include it in the next release. Note that in addition to the aliasing done by config.sub the src/mkheader build tool does some extra aliasing to avoid having too much identical syscfg files. Known Problems ============== On Windows, WSA Error Codes can be provided as system error codes and will be transparently converted to the corresponding gpg error codes. There are two problems with this support: * Not all error codes corresponding to WSA Error codes have a detailed description when printed with gpg_strerror. Some will default to "Unknown error" for pretty printing. For example, WSAEHOSTDOWN will be translated to GPG_ERR_EHOSTDOWN, but there is no corresponding EHOSTDOWN in Windows and thus gpg_strerror will default to "Unknown error" as printed by the system's strerror function for the argument WSAEHOSTDOWN. (This could be fixed by adding our own error strings replacing or extending the system error strings, including their translations). * The translation to a gpg error code and back to a system error code in some cases does not preserve information. For example, the error code WSAEACCES translates to GPG_ERR_EACCES, which translates back to EACCES. Any WSA Error code has either the first problem or the second (but not both), depending on if there is a corresponding Windows error code.