# this file is under Creative Commons License 3.0 cc-by-sa
0. What it is
The p≡p engine is a Free Software library encapsulating implementations of:
- Key Management
Key Management in p≡p engine is based on GnuPG key chains (NetPGP on iOS).
Keys are stored in an OpenPGP compatbile format and can be used for different
- Trust Rating
p≡p engine is sporting a two phase trust rating system. In phase one there is
a rating based on channel, crypto and key security named “comm_types”. In
phase 2 these are mapped to user representable values which have attached
colors to present them in traffic light semantics.
- Abstract Crypto API
The Abstract Crypto API is providing functions to encrypt and decrypt data or
full messages without requiring an application programmer to understand the
different formats and standards.
- Message Transports
p≡p engine will sport a growing list of Message Transports to support any
widespread text messaging system including E-Mail, SMS, XMPP and many more.
p≡p engine is written in C99. It is not meant to be used in application code
directly. Instead, p≡p engine is coming together with a list of software
adapters for a variety of programming languages and development environments.
p≡p engine is under Gnu General Public License v3. If you want to use it under
a different license, please contact mailto:firstname.lastname@example.org.
p≡p engine is depending on the following FOSS libraries:
* libetpan, see https://github.com/fdik/libetpan
git clone https://github.com/fdik/libetpan
* zlib, see http://zlib.net/
* OpenSSL, see http://openssl.org/
* iconv, see http://www.gnu.org/software/libiconv/
* Cyrus SASL, see http://cyrusimap.org/
* GnuPG via GPGME, version 1.6.0 or newer, see https://gnupg.org/
* NetPGP/p≡p, see https://cacert.pep.foundation/dev/repos/netpgp-et/
* Asn1c, download from https://lionet.info/soft/asn1c-0.9.27.tar.gz
(Debian's version 0.9.24 does not work)
* yml2, which needs lxml (where to get?)
2. Building p≡p engine
p≡p engine has an old style Makefile for building it.
The build is configured in Makefile.conf
It supports the common targets
$ make all
$ make install
$ make clean
$ make package # for building a .tar.bz2 with the source distribution
On Windows, use Visual Studio.
3. How to cross-build
For cross-building, BUILD_FOR is being used. I.e.:
$ BUILD_FOR=yourOS make -e
4. How to build the databases
p≡p Engine uses two databases: ~/.pEp_management (on *NIX) or
%LOCALAPPDATA%\pEp\management.db on Windoze respectively, and
/usr/local/share/system.db on *NIX or %ALLUSERSPROFILE%\pEp\system.db
respectively. The latter contains the Trustwords dbs.
The managment db is being created by the first call of init() of p≡p Engine. It
does not need to be created manually. system.db is being created by using the
DDL in db/create_system_db.sql – the content is created by db/dic2csv.py
out of hunspell's dictionary packages (or something similar) and then being
imported using sqlite3's .import command. Dictionary files for different
languages are part of p≡p engine source distribution.
$ make db
$ make -C db install
You can test the Trustwords in system.db using db/trustwords.py
Both Python tools have a switch --help
5. How to run the tests
You have to import all the test keys into your local gpg instance:
cat 0x*.asc *_sec.asc| gpg --import