Cipherpack - A Cryprographic Stream Processor

Original document location.

Git Repository

This project's canonical repositories is hosted on Gothel Software.


Cipherpack, a secure stream processor utilizing public-key signatures to authenticate the sender and public-key encryption of a symmetric-key for multiple receiver ensuring their privacy and high-performance message encryption.

Cipherpack securely streams messages through any media, via file using ByteInStream_File and via all libcurl network protocols using ByteInStream_URL are build-in and supported.
Note: libcurl must be enabled via -DUSE_LIBCURL=ON at build.

A user may use the media agnostic ByteInStream_Feed to produce the input stream by injecting data off-thread and a CipherpackListener to receive the processed output stream.

Cipherpack is implemented using C++17 or C++20 and is accessible via C++ and Java.

Please find the more detailed overview in the API doc.

Original use-case is a secure update process, elevating your installed firm- and software.
Hence original project name was Elevator.

See details on the C++ and Java API including its different C++ API level modules.


Build and clang-tidy clean on C++17 and C++20, passing all unit tests.

Supported Platforms

Language requirements

  • C++17 or C++20
  • Java 11, 17+ (optional)

See supported platforms for details.

Programming with Cipherpack


API Documentation

Up to date API documentation can be found:

Building Binaries

This project uses the following git submodules

Build Dependencies

  • CMake 3.13+ but >= 3.18 is recommended
  • C++ compiler
    • gcc >= 8.3.0 (C++17)
    • gcc >= 10.2.1 (C++17 and C++20)
    • clang >= 15 (C++17 and C++20)
  • Optional for lint validation
    • clang-tidy >= 15
  • Optional for vscodium integration
    • clangd >= 15
    • clang-tools >= 15
    • clang-format >= 15
  • Optional
    • libunwind8 >= 1.2.1
    • libcurl4 >= 7.74 (tested, lower may work)
  • Optional Java support
    • OpenJDK >= 11
    • junit4 >= 4.12

Install on FreeBSD

Installing build dependencies on FreeBSD >= 13:

pkg install git
pkg install sudo
pkg install cmake
pkg install libunwind
pkg install doxygen
pkg install squashfs-tools
pkg install bash
ln -s /usr/local/bin/bash /bin/bash

Install optional Java dependencies:

pkg install openjdk17
pkg install openjdk17-jre
pkg install junit

For Java ensure /etc/fstab includes:

fdesc   /dev/fd         fdescfs         rw      0       0
proc    /proc           procfs          rw      0       0

jau::fs::mount_image() and jau::fs::umount() are currenly not fully implemented under FreeBSD, hence testing using cmake option -DTEST_WITH_SUDO=ON is disabled.

To use URL streaming functionality via the curl library in jau_io_util.hpp and jau/io_util.cpp, the cmake option -DUSE_LIBCURL=ON must be set.
This also requires installation of the following packets:

pkg install curl
apt install mini-httpd

Note: mini-httpd is being used for unit testing URL streaming only.

Install on Debian or Ubuntu

Installing build dependencies on Debian (10 or 11):

apt install git
apt install build-essential g++ gcc libc-dev libpthread-stubs0-dev 
apt install clang-15 clang-tidy-15 clangd-15 clang-tools-15 clang-format-15
apt install libunwind8 libunwind-dev
apt install cmake cmake-extras extra-cmake-modules pkg-config
apt install doxygen graphviz

If using optional clang toolchain, perhaps change the clang version-suffix of above clang install line to the appropriate version.

After complete clang installation, you might want to setup the latest version as your default. For Debian you can use this clang alternatives setup script.

Install optional Java dependencies:

apt install openjdk-17-jdk openjdk-17-jre junit4

To test jau::fs::mount_image() and jau::fs::umount() under Linux with enabled cmake option -DTEST_WITH_SUDO=ON,
the following build dependencies are added

apt install libcap-dev libcap2-bin
apt install squashfs-tools

To use URL streaming functionality via the curl library in jau_io_util.hpp and jau/io_util.cpp, the cmake option -DUSE_LIBCURL=ON must be set.
This also requires installation of the following packets:

apt install libcurl4 libcurl4-gnutls-dev
apt install mini-httpd

Note: mini-httpd is being used for unit testing URL streaming only.

Build Procedure

To fetch the source tree use:

git clone --recurse-submodule git://jausoft.com/srv/scm/cipherpack.git
cd cipherpack

From here on we assume to be in the cipherpack project folder.

For a generic build use:

mkdir build
cd build
make -j $CPU_COUNT install
make test
make doc

The install target of the last command will create the include/ and lib/ directories with a copy of the headers and library objects respectively in your build location. Note that doing an out-of-source build may cause issues when rebuilding later on.

You may also invoke scripts/build.sh, which resolves installed environment variables like JAVA_HOME and JUNIT_CP as well as building and distributing using os_arch type folders.

  • scripts/setup-machine-arch.sh .. generic setup for all scripts
  • scripts/build.sh .. initial build incl. install and unit testing
  • scripts/rebuild.sh .. rebuild
  • scripts/build-cross.sh .. cross-build
  • scripts/rebuild-cross.sh .. cross-build
  • scripts/test_java.sh .. invoke a java unit test
  • scripts/test_exe_template.sh .. invoke the symlink'ed files to invoke native unit tests

Our cmake configure has a number of options, cmake-gui or ccmake can show you all the options. The interesting ones are detailed below:

Changing install path from /usr/local to /usr


Building debug build:


Add unit tests to build (default: disabled)


Add unit tests requiring sudo to build (default: disabled).
This option requires -DBUILD_TESTING=ON to be effective.
Covered unit test requiring sudo are currently

  • Linux OS
    • jau::fs::mount_image()
    • jau::fs::umount()

Using clang instead of gcc:

-DCMAKE_C_COMPILER=/usr/bin/clang -DCMAKE_CXX_COMPILER=/usr/bin/clang++

Building with clang and clang-tidy lint validation


Disable stripping native lib even in non debug build:


Enable using libcurl (default: disabled)


Enable using libunwind (default: disabled)


Disable using C++ Runtime Type Information (RTTI) (default: enabled)


Building debug and instrumentation (sanitizer) build:


Cross-compiling on a different system:

-DCMAKE_CXX_FLAGS:STRING=-m32 -march=i586
-DCMAKE_C_FLAGS:STRING=-m32 -march=i586

To build documentation run:

make doc

IDE Integration


IDE integration configuration files are provided for

  • Eclipse with extensions
    • CDT or CDT @ eclipse.org
    • Not used due to lack of subproject include file and symbol resolution:
      • CMake Support, install C/C++ CMake Build Support with ID org.eclipse.cdt.cmake.feature.group

From the project root directory, prepare the Debug folder using cmake


The existing project setup is just using external build via make.

You can import the project to your workspace via File . Import... and Existing Projects into Workspace menu item.

For Eclipse one might need to adjust some setting in the .project and .cproject (CDT) via Eclipse settings UI, but it should just work out of the box.

VSCodium or VS Code

IDE integration configuration files are provided for

For VSCodium one might copy the example root-workspace file to the parent folder of this project (note the filename change) and adjust the path to your filesystem.

cp .vscode/cipherpack.code-workspace_example ../cipherpack.code-workspace
vi ../cipherpack.code-workspace

Then you can open it via File . Open Workspace from File... menu item.

  • All listed extensions are referenced in this workspace file to be installed via the IDE
  • The local settings.json has clang-tidy enabled
    • If using clang-tidy is too slow, just remove it from the settings file.
    • clangd will still contain a good portion of clang-tidy checks


Cipherpack is provided by Gothel Software and Zafena ICT.

If you like to utilize Cipherpack in a commercial setting, please contact Gothel Software to setup a potential support contract.



  • Stable stream handling w/o knowledge of content-size under heavy load
  • jaulib v1.1.1
    • Fixed Java_org_jau_sys_Clock_get[Monotonic|WallClock]TimeImpl() for JNI callbacks
    • Fixed jau::io::ByteInStream_[URL|Feed] utilize blocking read-operations w/o knowledge of content-size


  • First stable release


  • Completed restructuring incl. stream CIPHERPACK_0003 and API doc
  • Completed Java binding, all tests passed


  • Renamed from Elevator to Cipherpack
  • namespace elevator::cipherpack -> cipherpack
  • Added pure streaming encryptThenSign() and checkSignThenDecrypt() base function


  • Working version with universal jau::io::ByteInStream and matured unit testing OK and error cases


  • Kick-off