# Eric
[](https://crates.io/crates/eric-bindings)
[](https://docs.rs/eric-bindings)
[](https://crates.io/crates/eric-sdk)
[](https://docs.rs/eric-sdk)
[](https://github.com/quambene/eric-rs/actions/workflows/ci.yml)
Rust bindings and SDK for the ELSTER Rich Client (ERiC)
- [What is ELSTER?](#what-is-elster)
- [What is ERiC?](#what-is-eric)
- [Requirements](#requirements)
- [Rust bindings](#rust-bindings)
- [Select bindings](#select-bindings)
- [Generate bindings](#generate-bindings)
- [Test bindings](#test-bindings)
- [Eric SDK](#eric-sdk)
- [Usage](#usage)
- [Supported Eric versions](#supported-eric-versions)
- [Test SDK](#test-sdk)
- [Changelog](#changelog)
## What is ELSTER?
Elster (short for _Elektronische Steuererklärung_) is a project by the German tax administration to process tax returns and declarations.
## What is ERiC?
ERiC (short for _Elster Rich Client_) is a shared C library that is integrated into a tax application. ERiC checks the data provided by the tax application for plausibility, and transmits the validated data in encrypted form to the computing center of the respective tax administration.
## Requirements
You need to have the shared library `libericapi.so` and the header file `ericapi.h` available on your system which can be downloaded from [ELSTER for developers](https://www.elster.de/elsterweb/entwickler/login) after access has been requested [here](https://www.elster.de/elsterweb/registrierung-entwickler/form).
## Rust bindings
Specify the path to the Eric library via environment variable `ERIC_PATH`. For
example:
``` bash
ERIC_PATH="ERiC-43.3.2.0-Linux-x86_64/ERiC-43.3.2.0/Linux-x86_64"
```
Relevant environment variables then default to
``` bash
LIBRARY_NAME=ericapi
LIBRARY_PATH="$ERIC_PATH/lib"
HEADER_FILE="$ERIC_PATH/include/ericapi.h"
PLUGIN_PATH="$ERIC_PATH/lib/plugins"
```
### Select bindings
Select bindings from the pre-generated bindings:
``` bash
cargo build -p eric-bindings
```
### Generate bindings
You can also generate bindings on-the-fly for your specific platform and
architecture by using feature flag `generate-bindings`:
``` bash
cargo build -p eric-bindings --features generate-bindings
```
The bindings are generated in
`target/debug/build/eric-bindings-<random-id>/out/bindings.rs`.
To generate the bindings on your platform and architecture, you need `libclang` as well. For example, on Debian/Ubuntu install:
``` bash
apt install llvm-dev libclang-dev clang
```
### Test bindings
The bindings are included in `src/lib.rs` via `include!` macro and tested by:
``` bash
cargo test -p eric-bindings --lib
```
Logs are written to `eric.log` in the current directory.
## Eric SDK
`eric-sdk` supports single-threaded Eric instances.
### Usage
To use `eric-sdk`, add the shared C library to your path (e.g. to `LD_LIBRARY_PATH` on Linux):
``` bash
export LD_LIBRARY_PATH="$ERIC_PATH/lib:$LD_LIBRARY_PATH"
```
To send the xml file, the path and password of the Elster certificate have to be provided via environment variables `CERTIFICATE_PATH` and `CERTIFICATE_PASSWORD`. External tests also require a `VENDOR_ID`.
### Supported Eric versions
Currently, only the latest version of the Eric library is supported.
| 0.1.0 | 0.2.0 | 38.1.6.0 |
| 0.2.0 | 0.3.0 | 39.6.4.0 |
| 0.3.0 | 0.4.0 | 40.1.8.0 |
| 0.4.0 | 0.5.0 | 43.3.2.0 |
### Test SDK
``` bash
# Run unit tests
cargo test -p eric-sdk --lib
# Run integration tests (requires ERiC library)
cargo test -p eric-sdk --test '*' -- --test-threads=1
```
To run those tests that interact with the ELSTER servers, you need to provide the following environment variables:
- `CERTIFICATE_PATH`: Path to your ELSTER certificate (`.pfx`)
- `CERTIFICATE_PASSWORD`: Password for your certificate
- `VENDOR_ID`: Your official ELSTER Vendor ID (Hersteller-ID)
``` bash
cargo test -p eric-sdk --test '*' --features external-test -- --test-threads=1
```
## Changelog
The `eric-rs` repository contains multiple crates with separate changelogs:
- `eric-bindings`: [view changelog](https://github.com/quambene/eric-rs/blob/main/eric-bindings/CHANGELOG.md)
- `eric-sdk`: [view changelog](https://github.com/quambene/eric-rs/blob/main/eric-sdk/CHANGELOG.md)