/keepass4web

An application that serves KeePass database entries on a web frontend

Primary LanguagePerlGNU General Public License v3.0GPL-3.0

Build

Table of Contents generated with DocToc

KeePass4Web

A mobile-friendly web application which serves KeePass database entries on a web frontend.

Written in Perl and JavaScript.

FEATURES

  • Users need to authenticate with one of the auth backends (LDAP, Htpasswd, SQL, ...) before they can open a database
  • Server can fetch databases from various locations (Filesystem, Seafile, Dropbox, ...)
  • Either all users get access to the same database or each user gets access to his/her own
  • Doesn't save master password, uses a new and unique encryption key to cache the database
  • Caches encrypted databases in shared memory (so it works with multiple web server workers)
  • Encryption key is stored in the kernel keyring and therefore doesn't swap to disk
  • Passwords, protected fields and files are encrypted separately (also the ones in history). The web server only decrypts requested information. This way other passwords don't stay in memory in plain text and don't leave the server
  • Server revokes encryption keys after a configurable user idle time, effectively removing access to the cached database
  • Web interface offers entry search and access to files stored inside the database. Also displays custom entry icons
  • Highly configurable

PREREQUISITES

This will probably only run under some flavour of Linux. The instructions assume a Linux environment. Below is a list of required packages and modules to run the application. For installation follow INSTALL.

Libraries / Packages
  • build-essential (building XS modules)
  • libkeyutils-dev
  • libkeyutils1
  • libapache2-mod-perl2 (if running mod_perl2 with apache2)
  • libmagic1
  • libmagic-dev
  • cpanminus (module installation)
Perl modules
Core
  • Kernel::Keyring
  • Dancer2
  • Dancer2::Plugin::Ajax
  • Dancer2::Session::Cookie (default session engine, Cookie in config)
  • IPC::ShareLite
  • File::KeePass
  • Crypt::URandom
  • File::LibMagic
  • Sereal::Encoder
  • Sereal::Decoder
  • Crypt::Mode::CBC
  • Crypt::Mac::HMAC
  • URI::Escape
Backend LDAP
  • Net::LDAP
Backend Htpasswd
  • Crypt::Eksblowfish::Bcrypt (bcrypt)
  • Authen::Htpasswd (md5, sha1, crypt, plain)
Backend Seafile
  • JSON
  • REST::Client
  • URI::Escape
Backend LWP
  • LWP::UserAgent
  • HTTP::Request::Common
  • URI::Escape
Backend Dropbox
  • WebService::Dropbox
Bundled modules, may become external
  • File::KeePass::Web
  • Auth::LDAP
  • Seafile::Client::REST

To build the JavaScript part you will also need npm (version 3+ recommended, else your node_modules directory will explode!) and therefore Node.js

INSTALL

Choose one of the following installation methods (from easiest to most difficult):

  • From docker image: See DockerHub

  • From Ubuntu PPA (14.04, 16.04, 18.04):

    • Add the repository, update and install the package (and packages for default backends)

      sudo add-apt-repository ppa:lixmal/keepass4web

      sudo apt-get update

      sudo apt-get install apache2 libapache2-mod-perl2 libnet-ldap-perl libdancer2-session-cookie-perl keepass4web

    • Make config changes to /etc/keepass4web/config_local.yml

  • From deb package (Debian/Ubuntu/...):

    • Install dependencies (also for module installation further below)

      sudo apt-get install build-essential libkeyutils-dev libkeyutils1 libmagic1 libmagic-dev libapache2-mod-perl2 cpanminus

    • Grab the deb from github: https://github.com/lixmal/keepass4web/releases

    • Install the package

      dpkg -i keepass4web_*.deb

    • Move to keepass4web dir

      cd /usr/share/keepass4web/

    • Follow MODULE INSTALLATION

    • Make changes to /etc/keepass4web/config_local.yml

  • From dist tar:

  • From source:

BUILDING

The minified, bundled file will be written to public/scripts/bundle.js

  • Install Node/npm, e.g. for Ubuntu

    sudo apt-get install npm

  • Install js modules

    npm install

  • Copy bootstrap font files

    cp node_modules/bootstrap/fonts/* public/fonts/

  • Build js bundle

    npm run build

  • For a non-uglified version you can run

    npm run dev

BUNDLING

Output will be a KeePass4Web-{VERSION}.tar.gz file, which includes all files required to run the app but without the development/build files

  • Follow BUILDING first, then run the perl make file

    perl Makefile.PL

  • Bundle the app to a tar

    make dist

  • Clean up afterwards

    make clean

MODULE INSTALLATION

E.g. for Ubuntu 14.04 with mod_perl2:

  • Install distro packages, if you haven't already

    sudo apt-get install build-essential libkeyutils-dev libkeyutils1 libmagic1 libmagic-dev libapache2-mod-perl2 cpanminus

  • Install dependencies with all backends, the recommended modules (for performance) and the suggested session engine (Cookie)

    cpanm --sudo --installdeps . --with-all-features --with-recommends --with-suggests

  • Alternatively, install dependencies with selected backends only

    cpanm --sudo --installdeps . --with-feature Dropbox --with-feature LDAP --with-recommends

CONFIGURATION

  • Copy or rename config.yml to config_local.yml

    cp config.yml config_local.yml

  • Do changes in config_local.yml. Settings in config_local.yml override those in config.yml

  • Change session_cookie_key to a long and random value if using Cookie in session, e.g.

    pwgen -ysN1 128

DEPLOYMENT

Running this app on a web server with mod_perl2 or fcgi is recommended but running as standalone app is possible as well (with Dancer2's capabilities).

  • Create the log directory (as defined in config_local.yml)

    sudo mkdir /var/log/keepass4web/

  • The directory the app lives in has to be readable by the user running the web server, e.g.

    sudo chown -R root:www-data /opt/keepass4web/ /var/log/keepass4web/

    chmod g+r -R /opt/keepass4web/

  • Addtionally, it needs write permissions on the log directory, e.g.

    chmod g+w /var/log/keepass4web/

  • Remove permissions on sensitive data for everyone else

    chmod o-rwx /opt/keepass4web/config*.yml /var/log/keepass4web/

  • For apache, enable the perl mod and ssl

    sudo a2enmod perl

    sudo a2enmod ssl

    sudo a2ensite default-ssl

Running apache2 using mod_perl2/Plack with TLS:

Example config default-ssl:

PerlSwitches -I/opt/keepass4web/lib/
PerlModule KeePass4Web::Apache2
PerlPostConfigHandler KeePass4Web::Apache2::post_config

<IfModule mod_ssl.c>
    <VirtualHost _default_:443>
    ServerName example.org

    SSLEngine on
    SSLCertificateFile    /etc/ssl/certs/ssl-cert-snakeoil.pem
    SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key

    PerlOptions +Parent
    <Location /keepass/>
        SetHandler perl-script
        PerlResponseHandler Plack::Handler::Apache2
        PerlSetVar psgi_app /opt/keepass4web/bin/app.psgi
    </Location>


    </VirtualHost>
</IfModule>
Using the standalone server

  • Run (as correct user)

    plackup bin/app.psgi --port 8080 --host localhost

  • Or

    DANCER_PORT=8080 DANCER_SERVER=localhost bin/app.psgi

  • Options for plackup can be found in man plackup or online

  • As there is no TLS, it is recommonded to run a front-end web server with reverse proxy, example config for apache:

    <IfModule mod_ssl.c>
    <VirtualHost _default_:443>
    ServerName example.org

    SSLEngine on
    SSLCertificateFile    /etc/ssl/certs/ssl-cert-snakeoil.pem
    SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key

    ProxyPass        /keepass/ http://localhost:8080/
    ProxyPassReverse /keepass/ http://localhost:8080/


    </VirtualHost>
</IfModule>
Open https://<domain>/keepass/ (notice the trailing slash)
Refer to Dancer2::Manual::Deployment for more options.

BACKENDS

Authentication

Credentials may be further passed to the database backend via auth_reuse_cred config option. This way users don't have to enter their credentials twice (for auth backend and database backend) if they are identical. Useful when the database backend server uses the same auth backend internally.

LDAP

Attempts to authenticate the user against an (external, not built-in) LDAP server (Microsoft AD, 389 Directory Server, OpenLDAP, ...)

Htpasswd

Authentication using apache htpasswd files. Support for plain, sha1, crypt, md5 and bcrypt. Only bcrypt is considered secure.

PAM (planned)
SQL (planned)

Database

Filesystem

Grabs the KeePass database from the local filesystem. No support for local key files if configured statically (in config_local.yml). Can get database and key file location from auth backend. Web server needs read access to the files.

Seafile

KeePass database is stored in the private cloud.

Locations for the database and the key file can be configured in config_local.yml (global for all users) or fetched from auth backend (individually per user). Location syntax is '<repository-id>/<path-to-database>', see config_local.yml for an example.

The server uses the (possibly auth backend) credentials to fetch a token from Seafile which is used for consequent requests. No user credentials are saved anywhere at any time!

Right now the server does all Seafile requests. It is planned to migrate to a model where the client fetches the token from the Seafile server (if on the same domain) and passes it to the app server. Logging into some service on behalf of the user is an anti-pattern, therefore it is not recommended for non private servers.

LWP

Backend to fetch database from http, ftp or any other protocol supported by the LWP module collection (see LWP NETWORK SUPPORT). Additional protocols can be added by installing corresponding modules (see LWP::Protocol modules). Supports per-user database and key file location from auth backend. No support for key files if configured statically (in config_local.yml). Basic auth is supported for http, but only globally (same for all users, even if urls differ). Otherwise it would be necessary to store the user credentials in the session, which might be not a good idea. Database upload (saving) is only implemented for http right now.

Username and password may also be supplied in the form of ftp://username:password@example.org/db.kdbx

Dropbox

First you need to register the app with Dropbox: Create App. Choose the type of access you need, give it a name (e.g. KeePass4Web). Add an redirect url pointing to you application, followed by callback, e.g. https://example.org/keepass/callback. Optionally, generate an access token. Putting the token into the config will limit all users to that one Dropbox account (unless they open the Dropbox link by themselves, for which they would need to know the app key). Put the displayed app key, the app secret and the redirect url into config_local.yml.

Now, once users log into the web application, they will be redirected to the Dropbox login page (unless already logged in). After logging in and granting the app access to Dropbox, they will be redirected back to the app.

The backend also can fetch key files from Dropbox, if per-user databases are supported by the auth backend.

For the format to use in config_local.yml/db_location or the auth backend see the Dropbox HTTP doc under Path formats or HTTP download next to Paramaters

WebDAV (planned)

MISCELLANEOUS

  • Show currently used shared segments

    sudo ipcs

  • Removing segments (effectively closing user databases)

    sudo ipcrm -M key

  • Show kernel keyrings in use (as root)

    sudo cat /proc/keys

    sudo cat /proc/key-users

  • Adding users to .htpasswd, using bcrypt (needs apache2-utils/httpd-tools)

    touch .htpasswd # create file

    htpasswd -B .htpasswd

    sudo chown root:www-data .htpasswd # change group

    chmod g+r,o-rwx .htpasswd # remove permission of others, add read to webserver user

LIMITATIONS

  • KeePass databases are read only for now

  • Caching of KeePass databases happens in SysV IPC shared memory, whose maximum size depends on the OS. Defined by shmall and shmmni kernel variables

    sudo cat /proc/sys/kernel/shmmni

    sudo cat /proc/sys/kernel/shmall

  • Limits of kernel keyring apply

  • Right now all cached databases are seralised and deserialised together. This means more simultaneously active users will make fetching databases from IPC slower for every user. A better approach would be using one shared segment per user, which would make one roundtrip perpetual

BUGS / CAVEATS / TODO

  • Using mod_perl, apache may create two kernel session keyrings, because it restarts directly after startup, effectively executing KeePass4Web::KeePass twice

  • Log may have 'Key has been revoked' messages: happens when session keyring gets revoked once user (who (re)started the server) logs out. Please file a bug report in this case.

  • More tests

SCREENSHOTS

Login

App

APP DETAILS / BACKGROUND

Sequence of client/server operations

Client                                                       Server


Load website /
                              request KeePass tree
                              -------------------->

                                                        Check sesssion

                              not authenticated
                              <--------------------

Redirect to /user_login
Show credentials dialog

                              user credentials
                              -------------------->

                                                        User auth (LDAP, SQL, ...)

                                           login OK
                              <--------------------

Redirect to /backend_login
Show backend login dialog

                              backend credentials
                              -------------------->

                                                        Init DB backend / receive backend token
                                           login OK
                              <--------------------

Redirect to /db_login
Show KeePass password dialog

                              KeePass credentials
                              -------------------->
                                                        Possibly decrypt backend repo
                                                        Get KeePass database from backend
                                                        Possibly get Key file from backend
                                                        Decrypt KeePass database with master key + key file
                                                        Encrypt all password fields
                                                        Encrypt serialised string with newly generated key
                                                        Put encryption key into kernel keyring
                                                        Write keyring ids to session
                                                        Put encrypted database into IPC shared memory
                                      decryption OK
                              <--------------------

Redirect to /
                              request KeePass tree
                              -------------------->

                                                        Get database from IPC shared memory
                                                        Get encryption key from session
                                                        Decrypt database with key

                                  Send KeePass tree
                              <--------------------
Show KeePass tree

...

Password request by user
                              Request pw entry
                              -------------------->

                                                        Get keyring id from session
                                                        Get encryption key from kernel keyring
                                                        Get database from IPC shared memory
                                                        Decrypt database
                                                        Decrypt requested password

                                  Send pw entry
                              <--------------------
Show cleartext pw



...


Page reload

                              Request KeePass tree
                              -------------------->
                                                        Get database from IPC shared memory

                                  Send KeePass tree
                              <--------------------
Show KeePass tree

COPYRIGHT AND LICENSING

This software is copyright (c) by Viktor Liu. It is released under the terms of the GPL version 3.

Most of the icons in the public/img/icons directory are released under the LGPL version 2, the licence can be found in the same directory. The remaining icons are public domain. As these icons are the same as the ones used by the original KeePass software, you can refer to the info there: Icon Acknowledgements.

The Seafile logo is copyright (c) by Seafile Ltd.