Welcome to GNU Taler What is Taler? ============== Taler is an electronic payment system providing the ability to pay anonymously using digital cash. Taler consists of a network protocol definition (using a RESTful API over HTTP), a Exchange (which creates digital coins), a Wallet (which allows customers to manage, store and spend digital coins), and a Merchant website which allows customers to spend their digital coins. Naturally, each Merchant is different, but Taler includes code examples to help Merchants integrate Taler as a payment system. Taler is currently developed by a worldwide group of independent free software developers and the DECENTRALISE team at Inria Rennes. Taler is free software and a GNU package (https://www.gnu.org/). This is an alpha release with a few known bugs, lacking a few important features, documentation, testing, performance tuning and an external security audit. However, you can run the code and it largely works fine. that does not work yet. This package also only includes the Taler exchange, not the other components of the system. Documentation about Taler can be found at https://taler.net/. Our bug tracker is at https://gnunet.org/bugs/. Joining GNU =========== This is a GNU program, developed by the GNU Project and part of the GNU Operating System. If you are the author of an awesome program and want to join us in writing Free Software, please consider making it an official GNU program and become a GNU maintainer. You can find instructions on how to do so at http://www.gnu.org/help/evaluation. We are looking forward to hacking with you! Dependencies: ============= These are the direct dependencies for running a Taler exchange: - GNUnet >= 0.13.4 - GNU libmicrohttpd >= 0.9.71 - Postgres >= 9.5 Project structure is currently as follows: src/include/ -- installed headers for public APIs src/util/ -- common utility functions (currency representation, Taler-specific cryptography, Taler-specific json support) src/pq/ -- Postgres-specific utility functions src/exchangedb/ -- Exchange database backend (with DB-specific plugins) src/exchange/ -- taler exchange server src/exchange-tools/ -- taler exchange helper programs src/exchange-lib/ -- libtalerexchange: C API to issue HTTP requests to exchange src/auditor/ -- tools to generate reports about financial performance and to validate that the exchange has been operating correctly src/benchmark/ -- tool to run performance measurements Getting Started =============== The following steps illustrate how to set up a exchange HTTP server. They take as a stub for configuring the exchange the content of 'contrib/exchange-template/config/'. 1) Create a 'test/' directory and copy the stubs in it: mkdir -p test/config/ cp exchange/contrib/exchange-template/config/* test/config/ cd test/ 2) Create the exchange's master with the tool 'gnunet-ecc': gnunet-ecc -g1 master.priv 3) Edit config/exchange-common.conf by replacing the right value on the line with the MASTER_PUBLIC_KEY entry with the fresh generated (ASCII version of) master.priv. This ASCII version is obtained by issuing: gnunet-ecc -p master.priv 4) Generate other exchange related keys ('denomination' and 'signing' keys), by issuing: taler-exchange-keyup -m master.priv -o auditor.in 5) A exchange needs a database to operate, so the following instructions relate to how to set up PostgreSQL. On debian, the two packages needed are: * postgresql * postgresql-client For other operating systems, please refer to the relevant documentation. In this settlement, the exchange will use a database called 'talercheck' and will run under the username through which 'taler-exchange-httpd' is launched. Thus assuming that this user is 'demo', we need to create a 'demo' role for postgresql and make him the owner of 'talercheck' database. To perform these administrative tasks we have to impersonate the 'postgres' (by default, postgres installation assigns privileges to such a user) user, then connect to the running DBMS. Issue the following: su # give your root password su - postgres psql # this is the command-line client to the DMBS # the following lines are SQL CREATE USER demo; CREATE DATABASE talercheck OWNER demo; # quit with CTRL-D 7) If any previous step has been successful, it is now possbile to start up the exchange web server (by default it will listen on port 4241); issue: taler-exchange-httpd -d `pwd` # assuming we did not move outside of the 'test' directory