GPGME - GnuPG Made Easy --------------------------- Copyright 2004, 2006, 2010, 2012 g10 Code GmbH 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. Introduction -------------- GnuPG Made Easy (GPGME) is a C language library that allows to add support for cryptography to a program. It is designed to make access to public key crypto engines like GnuPG or GpgSM easier for applications. GPGME provides a high-level crypto API for encryption, decryption, signing, signature verification and key management. GPGME uses GnuPG and GpgSM as its backends to support OpenPGP and the Cryptographic Message Syntax (CMS). GPGME runs best on GNU/Linux or *BSD systems. Other Unices may require small portability fixes, send us your patches. See the file COPYING.LESSER and each file for copyright and warranty information. Installation -------------- See the file INSTALL for generic installation instructions. Check that you have unmodified sources. See below on how to do this. Don't skip it - this is an important step! To build GPGME, you need to install libgpg-error (>= 1.8) and Libassuan (>= 2.0.2). For support of the OpenPGP protocol (default), you should use the latest version of GnuPG (>= 1.4) , available at: ftp://ftp.gnupg.org/gcrypt/gnupg/ For support of the CMS (Cryptographic Message Syntax) protocol, you need a GnuPG version >= 2.0. If configure can't find the `gpg' binary in your path, you can specify the location with the --with-gpg=/path/to/gpg argument to configure. If configure can't find the `gpgsm' binary in your path, you can specify the location with the --with-gpgsm=/path/to/gpgsm argument to configure. For building the GIT version of GPGME please see the file README.GIT for more information. How to Verify the Source -------------------------- In order to check that the version of GPGME which you are going to install is an original and unmodified one, you can do it in one of the following ways: a) If you have a trusted Version of GnuPG installed, you can simply check the supplied signature: $ gpg --verify gpgme-x.y.z.tar.gz.sig This checks that the detached signature gpgme-x.y.z.tar.gz.sig is indeed a a signature of gpgme-x.y.z.tar.gz. The key used to create this signature is either of: "pub 2048R/4F25E3B6 2011-01-12 Werner Koch (dist sig)" "pub 1024D/87978569 1999-05-13 Marcus Brinkmann Marcus Brinkmann " If you do not have this key, you can get it from any keyserver. You have to make sure that this is really the key and not a faked one. You can do this by comparing the output of: $ gpg --fingerprint 0x4F25E3B6 with the fingerprint published elsewhere. b) If you don't have any of the above programs, you have to verify the SHA1 checksum: $ sha1sum gpgme-x.y.z.tar.gz This should yield an output _similar_ to this: fd9351b26b3189c1d577f0970f9dcadc3412def1 gpgme-x.y.z.tar.gz Now check that this checksum is _exactly_ the same as the one published via the announcement list and probably via Usenet. Documentation --------------- For information how to use the library you can read the info manual, which is also a reference book, in the doc/ directory. The programs in the tests/gpg/ directory may also prove useful. Please subscribe to the gnupg-devel@gnupg.org mailing list if you want to do serious work.