EchoHub/docs/changelog/v0.2.12.md

v0.2.12

Private channels are now genuinely private: password-protected channels are end-to-end encrypted, so the server (and its operators) can gate joins and measure storage but cannot read message or file contents. The IRC gateway grows real MODE/TOPIC support and channel keys, and the client gets image "save original", a transparent-light theme, drag-and-drop file sending, Ctrl+V paste, and a fix for the intermittent Ctrl+W crash.

New Features

• End-to-end encrypted channels — creating a channel with a password now provisions a zero-knowledge room:
  • The passphrase never leaves the client. It derives (PBKDF2-SHA256, 210k iterations) two keys: an auth key sent to the server as the join credential, and a key-encryption key that never leaves the machine.
  • A random room content key encrypts every message and file with AES-256-GCM. The server only ever stores the room key wrapped under the passphrase, so it can gate joins and report a channel's message count, storage size, and attachments — but cannot decrypt any of it. Even the server owner cannot read a private room's contents.
  • Members' clients cache the derived room key locally (in the per-server config, like saved sessions) so the passphrase isn't retyped every launch; joining on a new device prompts for it once.
  • Change the passphrase with /passwd <old> <new> (channel creator only). The room key is re-wrapped, not rotated, so existing history stays readable and members who join later with the new passphrase can still read older messages.
  • Files and images are encrypted client-side before upload; for images the ASCII-art preview is rendered on the client and stored room-encrypted too. Sending images by URL is disabled in encrypted channels (the server can't fetch-and-render without the key).
  • End-to-end encrypted channels cannot be joined over the IRC gateway (that would require the server to hold the room key) — IRC JOIN returns 475 directing users to the EchoHub client.
• Password-protected channels — set an optional password when creating a channel (masked field in the Create Channel dialog, password on POST /api/channels). Passwords are BCrypt-hashed server-side; the join gate applies on first join only (existing members and the creator are unaffected). Protected channels show a * marker in the channel list and +k in the status bar
• Save original images — image messages now show a clickable "[↓ save original]" line under the ASCII-art preview that downloads the full-resolution original to your Downloads folder (decrypting locally in encrypted channels)
• /join <channel> [password] — join protected channels inline, or let the client prompt: joining a protected channel without a password opens a masked prompt that re-prompts on a wrong password
• IRC channel keys — JOIN #room <key> works against room passwords (RFC 1459 comma-paired key lists supported); keyless or wrong-key joins get 475 ERR_BADCHANNELKEY
• IRC MODE implemented — MODE #chan reports +k/+, MODE #chan +k <key> sets and -k clears the room password (channel creator or admin only), ban-list probes get a clean empty reply, and CHANMODES is advertised in ISUPPORT
• IRC TOPIC set support — the channel creator can change the topic from IRC; the change broadcasts to connected TUI clients (previously topic changes were rejected with a stub error)
• Drag & drop file sending — dropping a file (image, audio, anything) onto the terminal detects the pasted path and sends it through /send automatically, including multiple files at once
• Ctrl+V pastes into the message input (previously paste was only available via the right-click menu); Ctrl+Y works as an alias
• New TransparentLight theme — dark characters on a transparent background, for light terminal color schemes (/theme transparentlight)
• Timestamps in messages are now aware of the current culture and display the short time pattern for today's messages and the short date+time pattern for older messages.

Bug Fixes

• Fixed intermittent crash on Ctrl+W — Terminal.Gui binds Ctrl+W to clipboard-cut, and Windows clipboard contention (another app holding the clipboard) threw an unhandled Win32Exception that took the app down. Ctrl+W now deletes the previous word (readline behavior, no clipboard), and all clipboard shortcuts (Ctrl+X/C/V/Y) are guarded so transient clipboard failures log a warning instead of crashing
• Fixed emoji shortcode replacement permanently disabling itself if a cursor update threw mid-replacement
• IRC LIST no longer leaks private channels; protected channels are marked [+k]

API Changes

• ChannelDto gains isProtected and isEncrypted; CreateChannelRequest gains optional password, encryptionSalt, and wrappedRoomKey; SignalR JoinChannel takes an optional second password argument and JoinChannelResult gains passwordRequired, encryptionSalt, and wrappedRoomKey (older clients must update to join over SignalR)
• New endpoints: GET /api/channels/{channel}/crypto (public crypto metadata — salt only, never the wrapped key) and POST /api/channels/{channel}/rekey (creator-only passphrase change)
• The upload endpoint accepts type and content form fields for encrypted channels, where the client supplies the declared message type and room-encrypted content
• ImageToAsciiService and FileValidationHelper moved from EchoHub.Server to EchoHub.Core so the client can render ASCII art and detect file types for encrypted uploads
• New EF migrations AddChannelPasswordHash and AddChannelEncryptionEnvelope (applied automatically on server start)