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Building Passgen

Building passgen from source

If you want to work on Passgen, you can compile it from source. If you just want to try it, you can download pre-built and signed binaries from the Releases page.


To build, some dependencies are necessary.

  • C compiler (for example clang or gcc),
  • CMake (at least v3.10),
  • Build system (for example make or ninja),
  • libexecinfo (when building for musl instead of libc, such as with Alpine Linux),
  • Ruby,
  • Git (optional),
  • Coverage reporting tool (llvm-cov or lcov, optional),
  • libutf8proc (optional).

On Ubuntu or Debian, the base dependencies can be installed by running the following.

sudo apt install gcc make cmake libjansson-dev ruby

On Alpine Linux, this should do the trick:

apk add build-base cmake make jansson-dev git ruby llvm clang bash

On other systems, these packages should also be easily available.

Cloning the Repository

Before you can set up the build system, you must clone the Passgen repository. You can do this using Git. If you want to use the bundled version of libutf8proc, which is recommended, you have to make sure to also update the Git submodules.

git clone
git submodule update --init

Build System

This project uses the CMake build system. Basic building is done by creating a build folder, running CMake to set up the build system, and then executing it. For example:

mkdir build
cd build
cmake ..
make -j

The CMake-based build system can take some build configuration as command-line arguments. These are set using the -D flag. For example, to set the build type, you can run CMake like this:

cmake -DCMAKE_BUILD_TYPE=Release ..

Note that you usually have to delete and recreate the build folder if you want to change settings. These are all of the settings that it takes:

Setting Description
BUILD_UTF8PROC Build utf8proc, the library used to decode UTF-8. If set to false, it will attempt to use the system version of libutf8proc. Enabled by default.
BUILD_TOOLS Build utility binaries. These are only really needed for testing.
BUILD_BENCH Build the passgen-bench executable, which runs benchmarks against data structures, pattern parsing and password generation. Enabled by default.
BUILD_TESTING Build the passgen-test executable, which will run unit tests. It is recommended to always build this and run it to make sure there are no obvious issues with the build. Enabled by default.
LIBPASSGEN_STATIC Build the static libpassgen library. Enabled by default.
LIBPASSGEN_SHARED Build the shared libpassgen library. Enabled by default.
PASSGEN_STATIC Link the passgen utility against the static library rather than the dynamic one. Disabled by default.
PASSGEN_SECCOMP Enable seccomp filters. These will run at startup to lock passgen down into a sandbox-like mode, used to enhance security, but can be fragile. Disabled by default.
USE_SANITIZER Enables use of one of the LLVM sanitizers. Disabled by default.
CODE_COVERAGE Enable instrumentation for generating code coverage reports. Disabled by default.

Overriding Compiler

CMake will pick out the default C compiler on your system automatically. If you have multiple compilers installed (such as gcc and clang, for example), this might not do what you want. You can override the C compiler used by setting the CC environment variable when you initially set up the build system.

CC=clang cmake ..

Build types

CMake supports different build types. The Debug build type is recommended for development, this enables some extra checks in the code that are not normally present in the release build. These can be set with the CMAKE_BUILD_TYPE variable.


The supported build types are:

Type Description
Release Builds with optimisations.
Debug Builds without optimizations.
RelWithDebInfo Build with optimisations.
MinSizeRel Minimal executable size.

After Building

You may want to run tests after building:

make test
# or
./src/test/passgen-test -v

If the tests work, you can use the build passgen:

./src/cli/passgen -h

If you want to install the version of Passgen that you have installed locally, it is recommended that you do so by building a package from it and installing that package. That way, you get all of the data (man page, libraries, CLI) and it is simple to remove it again.

cpack -G DEB
apt install ./passgen_*_amd64.deb

See the Tooling section for more tooling options.