libmongocrypt

The companion C library for client side encryption in drivers.

Bugs / Feature Requests

If you have encountered a bug, or would like to see a new feature in libmongocrypt, please open a case in our issue management tool, JIRA:

Create an account and login.
Navigate to the MONGOCRYPT project.
Click Create Issue - Please provide as much information as possible about the issue type and how to reproduce it.

Documentation

See The Integration Guide to integrate with your driver.

See mongocrypt.h for the public API reference. The documentation can be rendered into HTML with doxygen. Run doxygen ./doc/Doxygen, then open ./doc/html/index.html.

Building libmongocrypt

On Windows and macOS, libmongocrypt can use the platform's default encryption APIs as its encryption backend. On other systems, one will want to install the OpenSSL development libraries, which libmongocrypt will use as the default encryption backend.

Then build libmongocrypt:

git clone https://github.com/mongodb/libmongocrypt
cd libmongocrypt
mkdir cmake-build && cd cmake-build
cmake ../
make

This builds libmongocrypt.dylib and test-libmongocrypt, in the cmake-build directory.

Installing libmongocrypt on macOS

Install the latest release of libmongocrypt with the following.

brew install mongodb/brew/libmongocrypt

To install the latest unstable development version of libmongocrypt, use brew install mongodb/brew/libmongocrypt --HEAD. Do not use the unstable version of libmongocrypt in a production environment.

Building libmongocrypt from source on macOS

First install Homebrew according to its own instructions.

Install the XCode Command Line Tools:

xcode-select --install

Then clone and build libmongocrypt:

git clone https://github.com/mongodb/libmongocrypt.git
cd libmongocrypt
cmake .
cmake --build . --target install

Then, libmongocrypt can be used with pkg-config:

pkg-config libmongocrypt --libs --cflags

Or use cmake's find_package:

find_package (mongocrypt)
# Then link against mongo::mongocrypt

Installing libmongocrypt on Windows

For Windows, there is a fixed URL to download the DLL and includes directory: https://s3.amazonaws.com/mciuploads/libmongocrypt/windows/latest_release/libmongocrypt.tar.gz

To download the latest unstable release, download from this URL: https://s3.amazonaws.com/mciuploads/libmongocrypt/windows/latest_release/libmongocrypt_unstable.tar.gz Do not use the unstable version of libmongocrypt in a production environment.

Testing

test-mongocrypt mocks all I/O with files stored in the test/data and test/example directories. Run test-mongocrypt from the source directory:

cd libmongocrypt
./cmake-build/test-mongocrypt

libmongocrypt is continuously built and published on evergreen. Submit patch builds to this evergreen project when making changes to test on supported platforms. The latest tarball containing libmongocrypt built on all supported variants is published here.

Troubleshooting

If OpenSSL is installed in a non-default directory, pass -DOPENSSL_ROOT_DIR=/path/to/openssl to the cmake command for libmongocrypt.

If there are errors with cmake configuration, send the set of steps you performed to the maintainers of this project.

If there are compilation or linker errors, run make again, setting VERBOSE=1 in the environment or on the command line (which shows exact compile and link commands), and send the output to the maintainers of this project.

Design Principles

The design of libmongocrypt adheres to these principles.

Easy to integrate

The main reason behind creating a C library is to make it easier for drivers to support FLE. Some consequences of this principle: the API is minimal, structs are opaque, and global initialization is lazy.

Lightweight

We decided against the "have libmongocrypt do everything" approach because it complicated integration, especially with async drivers. Because of this we decided no I/O occurs in libmongocrypt.

Releasing

Version number scheme

Version numbers of libmongocrypt must follow the format 1.[0-9].[0-9] for releases and 1.[0-9].[0-9]-(alpha|beta|rc)[0-9] for pre-releases. This ensures that Linux distribution packages built from each commit are published to the correct location.

Steps to release

Do the following when releasing:

Update CHANGELOG.md with the version being released.
If this is a new minor release (e.g. x.y.0):
- Update the Linux distribution package installation instructions in the below sections to refer to the new version x.y.
- Commit these changes (on master) so that both the master branch and the new branch you are about to create refer to the new branch (note that this means you will commit changes to this file, and CHANGELOG.md)
- Create a branch named rx.y.
- Update the libmongocrypt-release Evergreen project (requires auth) to set Branch Name to rx.y.
Commit, create a new git tag, like 1.0.0-rc123 or 1.0.0, and push.
- Push both the branch ref and tag ref in the same command: git push origin master 1.0.0-rc123 or git push origin r1.0 1.0.0
- Pushing the branch ref and the tag ref in the same command eliminates the possibility of a race condition in Evergreen (for building resources based on the presence of a release tag)
- Note that in the future (e.g., if we move to a PR-based workflow for releases, or if we simply want to take better advantage of advanced Evergreen features), it is possible to use Evergreen's "Trigger Versions With Git Tags" feature by updating both config.yml and the project's settings in Evergreen
Ensure the version on Evergreen with the tagged commit is scheduled. The following tasks must pass to complete the release:
- upload-all
- windows-upload. It is scheduled from the windows-upload-check task.
Create the release from the GitHub releases page from the new tag.
Submit a PR to update the Homebrew package https://github.com/mongodb/homebrew-brew/blob/master/Formula/libmongocrypt.rb. (Example).
If this is a new minor release (e.g. x.y.0), file a DOCSP ticket to update the installation instructions on Install libmongocrypt. (Example)
Update the release on the Jira releases page.

Installing libmongocrypt From Distribution Packages

Distribution packages (i.e., .deb/.rpm) are built and published for several Linux distributions. The installation of these packages for supported platforms is documented here.

Unstable Development Distribution Packages

To install the latest unstable development package, change 1.7 to development in the package URLs listed in the subsequent instructions. For example, https://libmongocrypt.s3.amazonaws.com/apt/ubuntu <release>/libmongocrypt/1.7 in the instructions would become https://libmongocrypt.s3.amazonaws.com/apt/ubuntu <release>/libmongocrypt/development. Do not use the unstable version of libmongocrypt in a production environment.

.deb Packages (Debian and Ubuntu)

First, import the public key used to sign the package repositories:

sudo sh -c 'curl -s --location https://www.mongodb.org/static/pgp/libmongocrypt.asc | gpg --dearmor >/etc/apt/trusted.gpg.d/libmongocrypt.gpg'

Second, create a list entry for the repository. For Ubuntu systems (be sure to change <release> to xenial, bionic, focal, or jammy, as appropriate to your system):

echo "deb https://libmongocrypt.s3.amazonaws.com/apt/ubuntu <release>/libmongocrypt/1.7 universe" | sudo tee /etc/apt/sources.list.d/libmongocrypt.list

For Debian systems (be sure to change <release> to stretch, buster, or bullseye, as appropriate to your system):

echo "deb https://libmongocrypt.s3.amazonaws.com/apt/debian <release>/libmongocrypt/1.7 main" | sudo tee /etc/apt/sources.list.d/libmongocrypt.list

Third, update the package cache:

sudo apt-get update

Finally, install the libmongocrypt packages:

sudo apt-get install -y libmongocrypt-dev

.rpm Packages (RedHat, Suse, and Amazon)

RedHat Enterprise Linux

Create the file /etc/yum.repos.d/libmongocrypt.repo with contents:

[libmongocrypt]
name=libmongocrypt repository
baseurl=https://libmongocrypt.s3.amazonaws.com/yum/redhat/$releasever/libmongocrypt/1.7/x86_64
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/libmongocrypt.asc

Then install the libmongocrypt packages:

sudo yum install -y libmongocrypt

Amazon Linux 2

Create the file /etc/yum.repos.d/libmongocrypt.repo with contents:

[libmongocrypt]
name=libmongocrypt repository
baseurl=https://libmongocrypt.s3.amazonaws.com/yum/amazon/2/libmongocrypt/1.7/x86_64
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/libmongocrypt.asc

Then install the libmongocrypt packages:

sudo yum install -y libmongocrypt

Amazon Linux

Create the file /etc/yum.repos.d/libmongocrypt.repo with contents:

[libmongocrypt]
name=libmongocrypt repository
baseurl=https://libmongocrypt.s3.amazonaws.com/yum/amazon/2013.03/libmongocrypt/1.7/x86_64
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/libmongocrypt.asc

Then install the libmongocrypt packages:

sudo yum install -y libmongocrypt

Suse

First, import the public key used to sign the package repositories:

sudo rpm --import https://www.mongodb.org/static/pgp/libmongocrypt.asc

Second, add the repository (be sure to change <release> to 12 or 15, as appropriate to your system):

sudo zypper addrepo --gpgcheck "https://libmongocrypt.s3.amazonaws.com/zypper/suse/<release>/libmongocrypt/1.7/x86_64" libmongocrypt

Finally, install the libmongocrypt packages:

sudo zypper -n install libmongocrypt

jorge-imperial/libmongocrypt

libmongocrypt

Bugs / Feature Requests

Documentation

Building libmongocrypt

Installing libmongocrypt on macOS

Building libmongocrypt from source on macOS

Installing libmongocrypt on Windows

Testing

Troubleshooting

Design Principles

Easy to integrate

Lightweight

Releasing

Version number scheme

Steps to release

Installing libmongocrypt From Distribution Packages

Unstable Development Distribution Packages

.deb Packages (Debian and Ubuntu)

.rpm Packages (RedHat, Suse, and Amazon)

RedHat Enterprise Linux

Amazon Linux 2

Amazon Linux

Suse