TNT/docs/CHANGELOG.md

Changelog

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.

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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

2025

• Ongoing development and improvements
• Bug fixes and optimizations
• Feature enhancements
• Optimize performance (2025-01-10)
• Code cleanup (2025-01-15)
• Code cleanup (2025-01-17)
• Add minor improvements (2025-01-22)
• Code cleanup (2025-01-28)
• Fix edge cases (2025-02-03)
• Update documentation (2025-02-06)
• Fix edge cases (2025-02-07)
• Add minor improvements (2025-02-26)
• Update dependencies (2025-02-27)
• Fix edge cases (2025-03-01)
• Fix bugs and improve stability (2025-03-06)
• Fix bugs and improve stability (2025-03-12)
• Minor fixes (2025-03-17)
• Add minor improvements (2025-03-18)
• Refactor code structure (2025-03-24)
• Update dependencies (2025-03-27)
• Improve error handling (2025-03-28)
• Improve error handling (2025-04-03)
• Update documentation (2025-04-07)
• Update documentation (2025-04-13)
• Code cleanup (2025-04-15)
• Fix bugs and improve stability (2025-04-16)
• Add minor improvements (2025-04-17)
• Minor fixes (2025-04-23)
• Code cleanup (2025-04-24)
• Fix edge cases (2025-04-25)
• Refactor code structure (2025-05-13)
• Fix edge cases (2025-05-14)
• Minor fixes (2025-06-03)
• Code cleanup (2025-06-05)
• Add minor improvements (2025-06-10)
• Fix bugs and improve stability (2025-06-18)
• Update dependencies (2025-06-24)
• Optimize performance (2025-06-30)
• Update documentation (2025-07-07)
• Refactor code structure (2025-07-17)
• Fix bugs and improve stability (2025-07-19)
• Refactor code structure (2025-07-21)
• Code cleanup (2025-07-27)
• Code cleanup (2025-08-04)
• Minor fixes (2025-08-28)
• Improve error handling (2025-09-05)
• Update documentation (2025-09-09)
• Code cleanup (2025-09-15)
• Fix bugs and improve stability (2025-09-19)
• Update documentation (2025-09-25)
• Fix bugs and improve stability (2025-10-06)
• Fix bugs and improve stability (2025-10-13)
• Fix bugs and improve stability (2025-10-16)
• Optimize performance (2025-10-17)
• Add minor improvements (2025-10-22)
• Code cleanup (2025-10-26)
• Add minor improvements (2025-10-28)
• Fix edge cases (2025-10-29)
• Fix bugs and improve stability (2025-10-30)
• Optimize performance (2025-11-04)
• Improve error handling (2025-11-07)
• Update documentation (2025-11-12)
• Fix bugs and improve stability (2025-11-14)
• Update documentation (2025-11-17)
• Add minor improvements (2025-11-18)
• Refactor code structure (2025-11-19)
• Fix bugs and improve stability (2025-11-20)
• Minor fixes (2025-11-24)