Encryption plugin for Emacs providing casual privacy through multiple cipher implementations.

• Three cipher implementations: Shift, XOR, and Caesar
• Full buffer or region-based encryption/decryption
• Password persistence with obfuscation
• Cipher preference persistence
• Smart toggle detection (auto-detects encrypted content)

(straight-use-package
 '(bytelocker :type git :host github :repo "abaj8494/bytelocker.el"))
(require 'bytelocker)
(bytelocker-setup)

(use-package bytelocker
  :straight (:type git :host github :repo "abaj8494/bytelocker.el")
  :config
  (bytelocker-setup))

Clone this repository and add to your load path:

(add-to-list 'load-path "/path/to/bytelocker.el")
(require 'bytelocker)
(bytelocker-setup)

(use-package bytelocker
  :load-path "/path/to/bytelocker.el"
  :config
  (bytelocker-setup))

All commands are available via the C-c e m prefix:

1. Open a file in Emacs
2. Press C-c e m t to toggle encryption (or C-c e m e to explicitly encrypt)
3. Select a cipher (first time only - choice is saved)
4. Enter a password (saved for session)
5. Save the file

To decrypt:

1. Open an encrypted file
2. Press C-c e m t (auto-detects encryption) or C-c e m d
3. Password and cipher are loaded from saved preferences

Select a region before running any command to encrypt/decrypt only the selected text.

(setq bytelocker-default-cipher 'xor)      ; Default: 'shift
(setq bytelocker-setup-keymaps nil)        ; Disable default keybindings
(setq bytelocker-data-directory "~/.config/bytelocker") ; Custom data directory

Bitwise rotation cipher. Each byte is rotated left/right by an amount derived from the password.

XOR-based encryption with rotation. Includes protection against null-input password leakage.

Character shifting cipher with XOR preprocessing. Provides null-byte handling protection.

Encrypted content follows this format:

---BYTELOCKER-ENCRYPTED-FILE---
<base64-encoded-encrypted-data>
---END-BYTELOCKER-ENCRYPTED-FILE---

This plugin is designed for casual privacy, not cryptographic security. The ciphers are educational/convenience implementations and should not be used for protecting highly sensitive data. Passwords are stored with basic obfuscation (not encryption).

Run tests:

make test

Or in Emacs:

M-x ert RET t RET

Generate coverage report (requires undercover.el):

# Text report to stdout
make coverage

# LCOV format (for tools like genhtml, codecov)
make coverage-lcov

To generate an HTML coverage report:

make coverage-lcov
genhtml coverage/lcov.info -o coverage/html
open coverage/html/index.html

MIT