TNT/docs/CHANGELOG.md

Changelog

Unreleased

Added

• Documented the stable SSH exec interface contract, including exit statuses and JSON field shapes for package tests, scripts, and future tntctl work.
• Added a public security policy, supported-version guidance, and GitHub issue templates for bug reports and feature requests.
• Added tntctl, a thin local wrapper around the documented SSH exec interface for health, stats, users, tail, post, help, and exit commands.
• Added explicit server configuration flags for bind address, public host, connection limits, rate limiting, idle timeout, and SSH log verbosity.
• Added a configurable soak test that keeps an interactive session open while repeatedly checking health, stats, users, reconnects, and post/tail behavior.
• Added a two-user TUI lifecycle regression test and user-lifecycle notes for the main onboarding, chat, help, history, search, private-message, nickname, action-message, and exit paths.
• Added a VHS tape draft for recording the core TNT terminal-chat experience.

Changed

• make install-systemd now rewrites the installed unit's ExecStart to match the selected PREFIX/BINDIR, so package builds that install to /usr produce a unit pointing at /usr/bin/tnt.
• Release preflight now checks the staged systemd unit path, and strict release checks also require a clean tree, tag-at-HEAD, changelog release section, and non-placeholder maintainer metadata.
• CI and release workflows now use explicit least-privilege repository permissions.
• The release guide now documents SemVer expectations, manual release review, smoke testing, and rollback steps.
• Package installs now include tntctl and its man page alongside tnt.
• SSH exec commands longer than the command buffer are now rejected with a usage error instead of being truncated and executed.
• SSH exec post now persists the message before broadcasting or returning posted, so persistence failures are not visible as successful room events.
• Mention and private-message bell notifications are now queued on the target client and flushed by that client's own session loop, so slow SSH writes do not block the sender's message path.
• Interactive client writes now pass through a bounded per-client outbox and flush against the remote SSH window from that client's session loop. Exec sessions still write synchronously to preserve script output ordering.
• Private-message inbox access now uses its own mutex instead of sharing the SSH channel write lock, reducing unrelated contention on slow clients.
• Client writes now check the SSH channel's remote window before writing and mark the client disconnected when the window is closed, avoiding the most direct slow-reader blocking path.
• make release-check can now run the soak test with RUN_SOAK=1, keeping longer runtime checks opt-in for local release validation.
• Room capacity and mention notification bookkeeping now follow TNT_MAX_CONNECTIONS instead of a hidden fixed 64-client array limit.
• Updated the roadmap to reflect completed tntctl, stable exec contract, and monitoring-interface work, leaving the remaining daemon naming and runtime queue work explicit.
• Strict release preflight now builds and installs from the local vX.Y.Z tag source archive, catching untracked files that would be missing from a GitHub source release.
• Release documentation now creates the local tag before strict release checks, matching the strict gate's tag-at-HEAD requirement.
• Split UI-language parsing from localized text lookup: src/i18n.c now owns locale/code parsing, while src/i18n_text.c owns the table-driven text catalog with coverage checks for every message ID.
• Kept command placeholders stable across localized output: Chinese help and usage text now uses ASCII metavariables such as <user> and <message>.
• Standardized user-facing :msg / :inbox terminology around "private message" / "私信" instead of mixing it with "whisper" wording.
• Kept localized startup CLI syntax stable by using 用法: tnt [options] instead of localizing the [options] metavariable.
• Moved SSH exec help rows into an exec_catalog module so command metadata no longer lives as one large translated blob inside the shared i18n table.
• Refreshed contributor and development guidance so new commands are added through command_catalog, exec_catalog, and i18n_text instead of stale ssh_server.c / inline-strcmp instructions.
• exec_catalog now owns SSH exec command matching as well as help metadata, reducing duplicate command knowledge in src/exec.c.
• Replaced hard-coded chat.m1ng.space examples with chat.example.com so public documentation does not imply a specific production host.
• Moved SSH exec usage text and argument-shape checks into exec_catalog, so src/exec.c no longer duplicates --json and required-message validation.
• Moved interactive command usage text and first-pass argument-shape checks into command_catalog, so known commands with bad arguments now show usage instead of unknown-command guidance.
• Renamed the internal language state from help-oriented names to UI-language names (ui_lang_t, client->ui_lang, and i18n_*_ui_lang) so future i18n work has a correctly named seam.
• Command names, aliases, help summaries, concise-manual command rows, and unknown-command suggestions now share a dedicated command_catalog module.
• COMMAND-mode output is now a small scrollable pager with j/k, page movement, g/G, and q/Esc close controls, so long :last and :search results are readable instead of being cut off by the terminal height.
• Collapsed the interactive help surface around a concise Unix-style :help manual and the ? full key reference; :support is no longer a user-facing command.
• First-use hints and unknown-command guidance now point users to :help instead of the removed support entry.
• The concise manual module is now named manual_text, and the redundant interactive :commands entrypoint was removed.
• The concise :help manual now stays within one command-output screen so it does not truncate on normal terminal sizes.
• Language selection is limited to stable codes (en, zh) and locale-shaped environment values; natural-language labels are not accepted as command arguments.
• Full-screen help now uses l to cycle the UI language through the i18n module instead of hard-coding one key per language.
• Language parsing, language-code output, and help-language cycling now share one internal language registry.
• Removed the unused MODE_HELP enum value and refreshed development-guide module descriptions for the split between language parsing and text lookup.
• i18n_text now indexes localized strings by UI_LANG_* instead of storing English/Chinese as hard-coded struct fields.
• command_catalog now uses the shared localized-string helper for help, manual, and usage text instead of per-field English/Chinese members.
• exec_catalog now uses the same localized-string helper for exec help summaries.
• Startup CLI help and option error formats now use the shared localized-string helper and English fallback path.
• The concise :help manual text now uses the shared localized-string helper around the command-catalog rows.
• The full-screen key reference now uses the shared localized-string helper around the command-catalog rows.
• SSH exec help headers and usage prefixes now use the shared localized-string helper and English fallback path.
• Documented i18n and user-facing text rules for English-first source text, stable command syntax, concise help copy, and translation-only localization.
• Rewrote the quick setup guide as a concise English-first user lifecycle document with a short Chinese notes section.
• The shared UI text catalog now uses the same localized-string initializer as the smaller text modules, avoiding GCC missing-braces warnings.

1.0.1 - 2026-05-24 - Release candidate hardening

Added

• Added a first i18n boundary: TNT_LANG / locale detection now chooses the default interactive UI language (en or zh) for username prompts, status hints, help output, and :support.
• Added :lang <en|zh> so users can switch the interactive UI language for their current session.
• COMMAND-mode :help, unknown-command guidance, language command output, and continuation prompts now follow the session UI language.
• The full-screen help title and footer now follow the session UI language, with UTF-8-aware title padding for Chinese.
• Common COMMAND-mode outputs now respect the session language, including :users headers and :mute-joins state text.
• Command-output and MOTD screen chrome now use the session UI language.
• Common command usage errors now stay in the session language, and bare :search, :msg, and :nick show usage instead of falling through to unknown-command guidance.
• Command output text for common interactive commands is now centralized in the i18n table instead of being scattered through command flow logic.
• TUI title-bar status labels, including online count, mute marker, and help hint, now follow the session UI language.
• Join, leave, and nickname-change system messages now use a dedicated system_message module, follow the sender's session language, and keep :mute-joins filtering compatible with both Chinese and English logs.
• The interactive welcome screen now follows the selected UI language, including the narrow-terminal fallback.
• Full-screen help and COMMAND-mode help now live in a dedicated help_text module, keeping large bilingual help copy out of TUI and command flow code.
• Session language, unknown-command, suggestion, and continuation prompts now use the shared i18n table instead of inline command-flow conditionals.
• Interactive and exec support guide copy now lives in a dedicated support_text module, with focused language-selection unit coverage.
• Exec-mode help, usage errors, unknown-command feedback, and post validation messages now follow TNT_LANG while preserving stable machine-readable command output.
• Startup CLI help and option errors now live in a dedicated cli_text module and follow TNT_LANG / locale for English and Chinese users.
• Idle-timeout disconnect notices now follow the session UI language.

Changed

• make test now fails on integration-test regressions; constrained local environments can use make test-advisory for the previous advisory behavior.
• Removed the duplicate deploy.yml CI workflow so automated checks stay focused on CI while production deployment remains manual.
• Fixed the per-IP connection-rate limit to allow the configured number of attempts before blocking, added unit coverage, and exposed make connection-limit-test for the black-box limit regression test.
• Security feature checks now use isolated ports and temporary state directories, so they no longer require timeout/gtimeout or write host_key / messages.log into the test directory.
• Added make security-test and make ci-test so local runs can use the same full verification path as GitHub Actions.
• Anonymous access checks now use isolated state, wait for real SSH health, avoid external timeout helpers, and run through make anonymous-access-test as part of make ci-test.
• Stress testing now uses isolated state, waits for real SSH health, avoids external timeout helpers, and is available through make stress-test.
• Basic integration tests now wait for real SSH health responses instead of sleeping for a fixed startup delay.
• Connection-limit tests now use shared SSH health readiness checks for both concurrent-session and connection-rate scenarios.
• CI memory-leak smoke checks now use an isolated state directory, wait for real SSH readiness, and clean up the exact server PID instead of pkill.
• CI memory-leak smoke checks now pre-generate the host key and use a longer valgrind readiness window, avoiding false failures during slow startup.
• Language parsing now tolerates surrounding whitespace and accepts the english alias, improving TNT_LANG and :lang ergonomics.
• Refreshed the development guide's command/keybinding instructions so they point at the current modular commands, exec, i18n, and help text files.
• Refreshed README and quick-reference module maps to match the current cli_text, help_text, support_text, i18n, exec, and rate-limit modules.
• NORMAL mode now opens at the latest visible messages instead of the oldest in-memory message. Use k/PageUp to browse older history and G/End to return to the latest messages.
• NORMAL mode status now shows the visible message range and points users to G latest when new messages arrive while they are browsing.
• NORMAL mode now keeps following the latest messages while the view is pinned to the bottom; scrolling upward switches into history browsing.
• NORMAL mode now accepts arrow keys, PageUp/PageDown, and Home/End in addition to the existing Vim-style keys.
• Message viewport and scroll-state rules now live in a focused history_view module instead of being split across input and rendering code.
• Added unit coverage for history_view scroll boundaries, live-follow state, and date-divider-aware latest windows.
• Status/input line rendering now lives in a focused tui_status module, keeping the main TUI renderer closer to layout orchestration.
• Added :support / support quick guides so interactive users and SSH exec clients can discover common actions and troubleshooting paths in-product.
• The GitHub workflow formerly named deploy now runs CI only; production deployment remains a manual operator action.
• Command output rendering now truncates ANSI-styled UTF-8 text without counting escape sequences as visible width or cutting color codes.
• Host-key generation now uses the non-deprecated libssh PKI API on libssh 0.12+ while keeping compatibility with older libssh releases.
• INSERT mode now shows a lightweight first-use hint for sending, browsing, and :support.
• :support is now task-oriented around common user goals, and mistyped commands suggest the nearest known command when possible.
• Added a local make release-check preflight for release/package validation without tagging, publishing, or deploying.
• CI now installs expect on Ubuntu so interactive integration tests run instead of being skipped, and runs make release-check on every push/PR.
• The tag-triggered release workflow now builds on native x64/arm64 runners, verifies artifact architecture, emits one checksum file, and creates a draft release for manual review instead of publishing immediately.
• The one-line installer now downloads checksums.txt, verifies the selected binary before installation, and fails fast on missing release assets.
• Added a Debian packaging metadata draft for the future Ubuntu PPA path, with lightweight validation in make release-check.
• Added an Arch .SRCINFO draft and AUR maintainer notes, with version/package checks in make release-check.
• Added Homebrew tap maintainer notes, and expanded make release-check to validate the formula class and libssh dependency.

2026-05-18 - Interactive input polish

Added

• Bracketed paste handling keeps multi-line pasted text in the input buffer until the user presses Enter, then sends it as one message.
• Input and paste overflow now rings the terminal bell when the 1023-byte message limit is reached.
• Added an interactive expect regression test for basic TTY input, bracketed paste, and overlong paste capping.
• Added the exec-mode regression test to the main make test path.

Fixed

• SSH exec clients now survive stdin EOF long enough to flush stdout, exit status, EOF, and channel close. This fixes non-interactive commands such as ssh localhost health and ssh user@host post "message".

2026-05-16 - Internal cleanup

Fixed

• message_load() now holds g_message_file_lock for the duration of the read. Previously :last [N] could race with message_save() and observe a half-written line.
• constant_time_strcmp() accumulates the length difference in size_t instead of unsigned char. The old code lost the length-mismatch signal when the two lengths differed by a multiple of 256.

Changed

• buffer_appendf() and buffer_append_bytes() moved to common.c; the two identical copies in ssh_server.c and tui.c have been removed.
• Removed TODO.md (both items completed) and docs/README.old (superseded by the root README.md).
• Trimmed the auto-generated 2025 entry block from this changelog.

2026-04-23 - Chat UX Commands and MOTD

Added

• :last [N] — show last N messages retrieved directly from the log file (1–50, default 10), bypassing the 100-message in-memory ring buffer limit
• :search <keyword> — case-insensitive full-text search across the entire message history on disk; returns the most recent 15 matches
• :mute-joins — per-client toggle to silence join/leave system notifications; title bar shows [静音] when active
• MOTD support — place motd.txt in the state directory; users see it on connect and press any key to enter chat
• message_search() — new function in message.c / message.h for log file keyword search with rolling result collection
• Updated in-TUI help screens (English and Chinese) with new commands

2026-03-10 - SSH Runtime & Unix Interface Update

Fixed

• moved SSH handshake/auth/channel setup out of the main accept loop
• replaced synchronous room-wide fan-out with room update sequencing and per-client refresh
• switched idle session handling to ssh_channel_poll_timeout() plus blocking reads so quiet sessions are not dropped incorrectly
• made -d/--state-dir create the runtime state directory automatically

Added

• SSH exec commands: help, health, users, stats --json, tail, post
• PTY window-change handling for terminal resize
• TNT_MAX_CONN_RATE_PER_IP for per-IP connection-rate control
• tests/test_exec_mode.sh
• tests/test_connection_limits.sh

Changed

• TNT_MAX_CONN_PER_IP now means concurrent sessions per IP
• stress tests now disable rate-based blocking so they exercise concurrency instead of self-throttling

2026-01-22 - Security Audit Fixes

Comprehensive security hardening addressing 23 identified vulnerabilities across 6 categories.

Critical

• [AUTH] Add optional access token authentication (TNT_ACCESS_TOKEN)
• [AUTH] Implement IP-based rate limiting (10 conn/IP/60s, 5-min block after 5 auth failures)
• [AUTH] Add global connection limits (default: 64, configurable via TNT_MAX_CONNECTIONS)

High Priority

• [BUFFER] Replace all strcpy() with strncpy() (3 locations)
• [BUFFER] Add buffer overflow checking in client_printf()
• [BUFFER] Implement UTF-8 validation to prevent malformed input and overlong encodings
• [SSH] Upgrade RSA key from 2048 to 4096 bits
• [SSH] Fix key file permission race with atomic generation (umask + temp file + rename)
• [SSH] Add configurable bind address (TNT_BIND_ADDR) and log level (TNT_SSH_LOG_LEVEL)
• [CONCURRENCY] Fix room_broadcast() reference counting race
• [CONCURRENCY] Fix tui_render_screen() message array TOCTOU via snapshot approach
• [CONCURRENCY] Fix handle_key() scroll position TOCTOU

Medium Priority

• [INPUT] Add username validation rejecting shell metacharacters and control chars
• [INPUT] Sanitize message content to prevent log injection attacks
• [INPUT] Enhance message_load() with field length and timestamp validation
• [RESOURCE] Convert message position array from fixed 1000 to dynamic allocation
• [RESOURCE] Enhance setup_host_key() validation (size, permissions, auto-regeneration)
• [RESOURCE] Improve thread cleanup with proper pthread_attr and error handling

New Environment Variables

• TNT_ACCESS_TOKEN - Optional password for authentication (backward compatible)
• TNT_BIND_ADDR - Bind address (default: 0.0.0.0)
• TNT_SSH_LOG_LEVEL - SSH logging verbosity 0-4 (default: 1)
• TNT_RATE_LIMIT - Enable/disable rate limiting (default: 1)
• TNT_MAX_CONNECTIONS - Max concurrent connections (default: 64)
• TNT_MAX_CONN_PER_IP - Max connections per IP (default: 5)

Security Summary

Category	Fixes	Impact
Buffer Security	3	Prevents overflows, malformed UTF-8
SSH Hardening	4	Stronger crypto, no races
Input Validation	3	Prevents injection, log poisoning
Resource Management	3	Handles large logs, prevents DoS
Authentication	3	Optional protection, rate limiting
Concurrency Safety	3	Eliminates races, crashes
TOTAL	19	23 vulnerabilities fixed

All changes maintain backward compatibility. Server remains open by default.

---

2025-12-02 - Stability & Testing Update

Fixed

• Double colon bug in vim command mode (: key consumed properly)
• strtok data corruption in command output rendering
• Use-after-free race condition (added reference counting)
• SSH read blocking issues (added timeouts)
• PTY request infinite loop
• Message history memory waste (optimized loading)

Added

• Reference counting for thread-safe client cleanup
• SSH read timeout (30s) and error handling
• UTF-8 incomplete sequence detection
• AddressSanitizer build target (make asan)
• Basic functional tests (test_basic.sh)
• Stress testing script (test_stress.sh)
• Static analysis target (make check)
• Developer documentation (HACKING)

Changed

• Improved error handling throughout
• Better memory management in message loading