New script xcrypt.py: end-to-end encryption for IRC messages

[AnonShell]

End-to-end encryption plugin for WeeChat IRC messages using AES-256-GCM.

Features:

• AES-256-GCM authenticated encryption
• PBKDF2-SHA256 key derivation with 600,000 iterations (OWASP recommended)
• Automatic encryption/decryption of PRIVMSG messages
• Visual indicators (green "E>" prefix) for decrypted messages
• Per-nick and per-channel password management
• Secure password storage with master passphrase

Requires: cryptography library
Python: 3.8+

Documentation: https://anonshell.com/xcrypt/

Script info

• Script name: xcrypt.py
• Version: 1.0.0

• Requirements: cryptography

• Min WeeChat version:

• Script tags: encryption, security, privacy, irc

Description

xcrypt provides end-to-end encryption for WeeChat IRC messages (private messages and channels) using AES-256-GCM authenticated encryption. Users set a shared password per nick or channel via /xcrypt set, and all PRIVMSG messages are automatically encrypted before sending and decrypted upon receiving. The plugin uses PBKDF2-SHA256 with 600,000 iterations for key derivation. Decrypted messages display a green "E>" prefix. Encryption passwords can be stored securely using a master passphrase.

Checklist (new script)

• Single commit, single file added
• Commit message: New script name.py: short description…
• No similar script already exists
• Name: max 32 chars, only lower case letters, digits and underscores
• Unique name, does not already exist in repository
• No shebang on the first line
• Comment in script with name/pseudo, e-mail and license using SPDX tags (see Contributing guide)
• Only English in code/comments
• Pure WeeChat API used, no extra API
• Function hook_url, hook_process or hook_process_hashtable is used for any blocking call
• For Python script: works with Python 3 (Python 2 support is optional)
• Score 100 / 100 displayed by weechat-script-lint

Checklist (script update)

• Author has been contacted
• Single commit, single file added
• Commit message format: script_name.py X.Y: …
• Script version and Changelog have been updated
• For Python script: works with Python 3 (Python 2 support is optional)
• Score 100 / 100 displayed by weechat-script-lint

Checklist (script deletion)

• Author has been contacted
• Single commit, single file deleted
• Commit message format: Remove script name.py with reasons in description