Googlemail integration for encrypting, decrypting or signing emails.

GPG4Browsers is a prototype implementation of the OpenPGP Message Format [RFC 4880]. The implementation is currently written as Chrome Browser Extension with a Googlemail integration for encrypting, decrypting or signing emails.

The OpenPGP implementation supports all asymmetric, symmetric ciphers (except IDEA) and hash functions specified in the standard and implements the following use cases:

• Encryption and decryption of messages
• Sign and verify message signatures
• Import and export of certificates

The implementation is compatible with the GnuPG implementation standard settings except the standard compression used. To create a compatible message in GnuPG use the option --compress-algo none.

Limitations and Licensing

The code is released under the GNU Lesser Public License.

The implementation currently not supports:

• Generation, manipulation or creation of signatures on keys
• Several signature types on keys
• Symmetric only encrypted messages
• Compressed data packets

Contributions

The following code of other projects has been modified or used for this project:

Component	Contributor
AES library	Herbert Hanewinkel
CAST5 library	pjacobs@xeekr.com with modifications from Herbert Hanewinkel
DES library	Paul Tero with modification from Michael Hayworth
Blowfish library	nklein software (Patrick Fleckenstein)
Twofish library	Atsushi Oka
SHA library	Brian Turek
MD5 library	Henri Torgemane
RIPEMD/160	Derek Buitenhuis
Base64 encoding library	Herbert Hanewinkel
JS BigNum library	Tom Wu
OpenPGP CFB	Partially from Herbert Hanewinkel
UI library	The jQuery Project

Get the code

The current release is available as ZIP archive here.

The source code is located in the following subversion repository:http://gpg4browsers.recurity.com/svn/gpg4browsers/

Install

To install the extension perform the following steps:

• Get the source code
• Open chrome://extensions in the google-chrome browser
• Enable the developer mode on the far right
• Click on "Load unpacked extension .." and select the source code folder where the manifest file is located
• Check the "Allow in incognito" option.

Setup

For using the Browser extension you need to import private and public OpenPGP keys. This can be done by using the extensions options page linked at chrome://extensions. The options page allows to search keys on a public key server which exposes the service at port 80.

Usage

• Login to google mail
• Click on the page action (on the right side of the address bar within your google mail tab) to create a openpgp message
• When an OpenPGP signed or encrypted message is displayed in the google mail interface a popup occurs allowing the mail to be opened with GPG4Browsers.

Documentation

The source code is documented using JavaDoc annotation. An architectural overview as well as example code can be found in the Developer Documentation (PDF).

Source : http://gpg4browsers.recurity.com/