README
1libgpg-error
2============
3
4This is a library that defines common error values for all GnuPG
5components. Among these are GPG, GPGSM, GPGME, GPG-Agent, libgcrypt,
6Libksba, DirMngr, Pinentry, SmartCard Daemon and more.
7
8libgpg-error is free software; you can redistribute it and/or modify
9it under the terms of the GNU Lesser General Public License as
10published by the Free Software Foundation; either version 2.1 of the
11License, or (at your option) any later version. See the file
12COPYING.LIB for copyright and warranty information.
13
14However, some files (for example src/mkerrnos.awk) used in the build
15process of the library are covered by a different license. Please see
16the header of these files and the file COPYING for copyright and
17warranty information on these files. A special exception in the
18copyright license of these files makes sure that the output in the
19build process, which is used in libgpg-error, is not affected by the
20GPL.
21
22
23Installation
24------------
25
26Please read the file INSTALL!
27
28Here is a quick summary:
29
301) Check that you have unmodified sources. You can find instructions
31 how to verify the sources below. Don't skip this - it is an
32 important step!
33
342) Unpack the archive. With GNU tar you can do it this way:
35 "tar xjvf libgpg-error-x.y.tar.bz2"
36
373) "cd libgpg-error-x.y"
38
394) "./configure"
40
415) "make"
42
436) "make install"
44
45
46How to Verify the Source
47------------------------
48
49In order to check that the version of libgpg-error which you are going
50to install is an original and unmodified copy of the original, you can
51do it in one of the following ways:
52
53a) If you already have a trusted version of GnuPG installed, you can
54 simply check the supplied signature:
55
56 $ gpg --verify libgpg-error-x.y.tar.bz2.sig
57
58 This checks that the detached signature libgpg-error-x.y.tar.bz2.sig
59 is indeed a a signature of libgpg-error-x.y.tar.bz2.
60
61 Please note that you have to use an old version of GnuPG to do all
62 this stuff. *Never* use the version which was built using the
63 library you are trying to verify!
64
65b) If you don't have any a trusted version of GnuPG, you can attempt
66 to verify the SHA1 checksum, using a trusted version of the sha1sum
67 program:
68
69 $ sha1sum libgpg-error-x.y.tar.bz2
70
71 This should yield an output _similar_ to this:
72
73 610064e5b77700f5771c8fde2691c4365e1ca100 libgpg-error-x.y.tar.bz2
74
75 Now check that this checksum is _exactly_ the same as the one
76 published via the announcement list and probably via Usenet.
77
78
79Hints
80-----
81
82To build for Windows you you may use the convenience command:
83
84 ./autogen.sh --build-w32
85
86which runs configure with suitable options. For WindowsCE the command
87is:
88
89 ./autogen.sh --build-w32ce
90
91
92Known Problems
93--------------
94
95On Windows, WSA Error Codes can be provided as system error codes and
96will be transparently converted to the corresponding gpg error codes.
97There are two problems with this support:
98
99* Not all error codes corresponding to WSA Error codes have a detailed
100 description when printed with gpg_strerror. Some will default to
101 "Unknown error" for pretty printing. For example, WSAEHOSTDOWN will
102 be translated to GPG_ERR_EHOSTDOWN, but there is no corresponding
103 EHOSTDOWN in Windows and thus gpg_strerror will default to "Unknown
104 error" as printed by the system's strerror function for the argument
105 WSAEHOSTDOWN. (This could be fixed by adding our own error strings
106 replacing or extending the system error strings, including their
107 translations).
108
109* The translation to a gpg error code and back to a system error code
110 in some cases does not preserve information. For example, the error code
111 WSAEACCES translates to GPG_ERR_EACCES, which translates back to
112 EACCES.
113
114Any WSA Error code has either the first problem or the second (but not
115both), depending on if there is a corresponding Windows error code.
116