EasyCrypt: Computer-Aided Cryptographic Proofs
====================================================================
[](https://travis-ci.org/EasyCrypt/easycrypt)
EasyCrypt is a toolset for reasoning about relational properties of
probabilistic computations with adversarial code. Its main application
is the construction and verification of game-based cryptographic
proofs.
Table of Contents
--------------------------------------------------------------------
* [EasyCrypt: Computer-Aided Cryptographic Proofs](#easycrypt-computer-aided-cryptographic-proofs)
- [Installation requirements](#installation-requirements)
- [Installing OPAM (POSIX systems)](#installing-opam-posix-systems)
- [Installing requirements using OPAM (POSIX systems)](#installing-requirements-using-opam-posix-systems)
- [Installing requirements using OPAM (non-POSIX systems)](#installing-requirements-using-opam-non-posix-systems)
* [Configuring Why3](#configuring-why3)
* [Installing/Compiling EasyCrypt](#installingcompiling-easycrypt)
* [Proof General Front-End](#proof-general-front-end)
- [Installing using opam](#installing-using-opam)
- [Installing from sources](#installing-from-sources)
Installation requirements
--------------------------------------------------------------------
EasyCrypt uses the following third-party tools/libraries:
* OCaml (>= 4.02, 4.05)
Available at http://caml.inria.fr/
* OCamlbuild (only for OCaml >= 4.03)
* Why3 (>= 0.87, < 0.88)
Available at
Why3 must be installed with a set a provers.
See
Why3 libraries must be installed (make byte && make install-lib)
* Menhir
* OCaml Batteries Included
* OCaml PCRE (>= 7)
* OCaml Zarith
* OCaml ini-files
On POSIX/Win32 systems (GNU/Linux, *BSD, OS-X), we recommend that users
install EasyCrypt and all its dependencies via `opam`.
Installing OPAM (POSIX systems)
--------------------------------------------------------------------
Opam can be easily installed from source or via your packages manager:
* On Ubuntu and derivatives:
```
$> add-apt-repository ppa:avsm/ppa
$> apt-get update
$> apt-get install ocaml ocaml-native-compilers camlp4-extra opam
```
* On Fedora/OpenSUSE:
```
$> sudo dnf update
$> sudo dnf install ocaml ocaml-docs ocaml-camlp4-devel opam
```
* On MacOSX using brew:
```
$> brew install ocaml opam
```
Once `opam` and `ocaml` has been successfully installed run the following:
```
$> opam init
$> eval $(opam env)
```
For any issues encountered installing `opam` see:
* [https://opam.ocaml.org/doc/Install.html] for detailed opam installation instructions.
* [https://opam.ocaml.org/doc/Usage.html] for how to initialize opam.
To install `opam` on non-POSIX systems
[see the section below](#installing-requirements-using-opam-non-posix-systems).
Installing requirements using OPAM (POSIX systems)
--------------------------------------------------------------------
Starting with opam 1.2.0, you can install all the needed dependencies
via the opam OCaml packages manager.
0. Optionally, switch to a dedicated compiler for EasyCrypt:
```
$> opam switch -A $OVERSION easycrypt
```
where `$OVERSION` is a valid OCaml version (e.g. 4.02.1)
1. Add the EasyCrypt repository:
```
$> opam repository add easycrypt git://github.com/EasyCrypt/opam.git
$> opam update
```
2. Optionally, select the EasyCrypt (git) branch you want to use:
```
$> opam pin -n add easycrypt https://github.com/EasyCrypt/easycrypt.git#branch
```
where `branch` is the branch name you want to use (e.g. `aprhl`).
In that case, we advise you to create a dedicated opam switch
(see first step above).
3. Optionally, use opam to install the system dependencies:
```
$> opam install depext
$> opam depext easycrypt
```
4. Add the EasyCrypt meta-packages:
```
$> opam install --deps-only easycrypt
$> opam install ec-provers
```
If you get errors about OCaml Build failing because it's already installed, the
check can be skipped with the following:
```
CHECK_IF_PREINSTALLED=false opam install --deps-only easycrypt
```
Installing requirements using OPAM (non-POSIX systems)
--------------------------------------------------------------------
You can install all the needed dependencies via the opam OCaml packages manager.
1. Install the opam Ocaml packages manager, following the instructions at:
https://fdopen.github.io/opam-repository-mingw/installation/
2. Add the EasyCrypt repository:
```
$> opam repository add easycrypt git://github.com/EasyCrypt/opam.git
$> opam update
```
3. Optionally, select the EasyCrypt (git) branch you want to use:
```
$> opam pin -n add easycrypt https://github.com/EasyCrypt/easycrypt.git#branch
```
where `branch` is the branch name you want to use (e.g. `aprhl`).
4. Use opam to install the system dependencies:
```
$> opam install depext depext-cygwinports
$> opam depext easycrypt
```
5. Add the EasyCrypt meta-packages:
```
$> opam install --deps-only easycrypt
$> opam install alt-ergo
```
6. You can download extra provers at the following URLs:
* Z3: [https://github.com/Z3Prover/z3]
* EProver: [http://wwwlehre.dhbw-stuttgart.de/~sschulz/E/E.html]
Configuring Why3
====================================================================
Before running EasyCrypt and after the installation/removal/update
of an SMT prover, you need to (re)configure Why3.
```
$> why3 config --detect
```
EasyCrypt is using the default Why3 location, i.e. ~/.why3.conf.
If you have several versions of Why3 installed, it may be impossible
to share the same configuration file among them. EasyCrypt via the
option -why3, allows you to load a Why3 configuration file from a
custom location. For instance:
```
$> why3 config --detect -C $WHY3CONF.conf
$> ./ec.native -why3 $WHY3CONF.conf
```
where `$WHY3CONF` must be replaced by some custom location.
Installing/Compiling EasyCrypt
====================================================================
If installing from source, running
```
$> make
$> make install
```
builds and install EasyCrypt (under the binary named `easycrypt`),
assuming that all dependencies have been successfully installed. If
you choose not to install EasyCrypt system wide, you can use the
binary `ec.native` that is located at the root of the source tree.
It is possible to change the installation prefix by setting the
environment variable PREFIX:
```
$> make PREFIX=/my/prefix install
```
EasyCrypt comes also with an opam package. Running
```
$> opam install easycrypt
```
installs EasyCrypt and its dependencies via opam. In that case, the
EasyCrypt binary is named `easycrypt`.
Proof General Front-End
====================================================================
Installing using opam
--------------------------------------------------------------------
If you installed the EasyCrypt dependencies using opam, you can
install ProofGeneral via opam too. Running
```
$> opam install proofgeneral
```
installs ProofGeneral along with its EasyCrypt mode. You still have to
tweak your emacs configuration file (~/.emacs) to load
ProofGeneral by adding the following line to it
```
(load-file "$proof-general-home/generic/proof-site.el")
```
where `$proof-general-home` should be replaced by
```
$prefix/share/proofgeneral
```
with `$prefix` being set to the output of
```
$> opam config var prefix
```
Installing from sources
--------------------------------------------------------------------
EasyCrypt mode has been integrated upstream. Please, go
to and follow the instructions.