README

SLIME S/MIME

Plugin to provide security via S/MIME 4.0 standard (RFC 8551).

Plugin stores all data safely on the server therefore requires user
to trust the server. This approach violates end-to-end principle but
allows easier usage. 

REQUIREMENTS
------------
- Roundcube version 1.6.0+
- OpenSSL version 3+

INSTALLATION
------------

1. Set configuration in config.inc.php.dist and preferably
   create a new directory for storing the certificates.
2. Ensure that directory for certificates is writable.  
3. Rename it to config.inc.php.

FUNCTIONALITY
------------

- Encrypting via CMS EnvelopedData and AuthEnvelopedData, 
- Signing via Content-type: multipart/signed
- Additional way of distributing certificates via attachments
- Hierarchical certificate store 
- Real-time certificate validation with each import/composed message/viewed message
- Supports both older and modern symmetric algorithms (older contain warnings and can be turned off)

TODO
----

- Encrypted responds should show message of the responder when composing
- Certificate trust levels in certificate information
- Be able to select different imported certificate for encrypting/signing 
- Import/Export/Deletion of multiple certificates at the same time
- Changing password should change password hash
- Deleting user folder when account deleted
- Compression of the content before signing or encrypting (CompressionData)
- Enable to secure PK in PKCS#12 with an additional layer via security phrase
- Client side signing (selectable) -> enable not to store private keys on the server
- Mode in advanced settings, that enables overriding identities with the first usable cert 

LICENSE DETAILS
---------------

MIT License

Copyright (c) 2025 Zdenek Dobes

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.