telnetlib3

• yield drain() after telnetlib3-client stdout.write() by @jquast in #145

Full Changelog: 4.0.4...4.0.5

• bugfix servers using robot_check=True+encoding=False by @jquast in #144

Full Changelog: 4.0.3...4.0.4

• bugfix: long-running servers leaked memory through :class:~telnetlib3.server.Server _protocols list and _new_client asyncio.Queue. Both are now bounded and regularly pruned.

• enhancement: telnetlib3.telnet now overlays std library module space, import telnetlib :ghissue:139.

• enhancement: telnetlib3-fingerprint-server and telnetlib3-fingerprint client now also detect "telnet loops" and "wrong direction" errors in opposing IAC parser.

• removed: telnetlib3-fingerprint-server no longer integrates with the (never released) tv-detect package for terminal vulnerability probing.

• provide legacy 'import telnetlib' compatibility by @jquast in #141

• Refactor and remove tv-detect by @jquast in #142

Full Changelog: 4.0.2...4.0.3

• bugfix: MCCP2 decompression failed on MUD servers using raw deflate or gzip-wrapped compression,
  producing garbled banners. The client now auto-detects zlib/gzip format and falls back to raw
  deflate when needed.
• bugfix: NEW_ENVIRON SEND requests that exceed the 256-byte subnegotiation buffer of some
  telnet clients (e.g. GNU inetutils) are now automatically split into multiple SB frames.
• bugfix: telnetlib3-server argument --tls-auto deadlocked with plain telnet clients.
  Detection now uses a non-blocking with a configurable timeout.
• enhancement: writer.get_extra_info("ssl_object") is available in shell callbacks to detect
  TLS-secured connections and query the negotiated protocol version and cipher.
• enhancement: telnetlib3-fingerprint-server integrates with the optional tv-detect
  package for terminal vulnerability probing.

What's Changed

• bugfix TypeError in request_charset() by @jquast in #129
• Kludge mode fix (WILL SGA/DO SGA) by @jquast in #130
• LINEMODE negotiation fixes by @jquast in #131
• Remove color_filter module (Moving to Telix) by @jquast in #132
• sort arguments alphabetically by @jquast in #133
• Add --always-dont and --always-wont=TEL,OPTS by @jquast in #134
• bugfix connection burst sometimes loses ECHO mode by @jquast in #135
• New 'big5bbs' encoding! by @jquast in #136
• Support Windows for telnetlib3-client by @jquast in #137

Full Changelog: 3.0.1...4.0.1

• removed: telnetlib3.color_filter. ColorFilter, ColorConfig, PALETTES,

  PetsciiColorFilter, and AtasciiControlFilter have all been moved to the downstream Telix project, recommended for connecting to legacy BBSs systems requiring color correction.

  telnetlib3-client CLI args --colormatch, --color-brightness, --color-contrast, --background-color, --ice-colors removed.

• bugfix: server and client now correctly complete LINEMODE negotiation when prompted to. * new: --logfile-mode {append,rewrite} and --typescript-mode CLI flags

  and ~telnetlib3.accessories.make_logger filemode argument control whether the log file is appended to (default) or overwritten on each connection.

  • new: ~telnetlib3.client_shell.LinemodeBuffer used by telnetlib3-client, a client-side line buffer for LINEMODE EDIT mode with local erase-char, erase-line, erase-word editing, forwardmask flushing, and TRAPSIG IAC command generation. The default 'telsh' server was also updated to support linemode.

• bugfix: ~telnetlib3.stream_writer.TelnetWriter.request_charset raised TypeError,

  128. Offer callbacks (no-arg, returning a list of items to propose) are now separated from send callbacks (which respond to received requests) via new ~telnetlib3.stream_writer.TelnetWriter.set_ext_offer_callback method.

• change: Unused client argument gmcp_log removed.
• new: MCCP2 and MCCP3. Both client and server ends passively support if requested, and request support by --compression or deny support by --no-compression.

Full Changelog: 3.0.0...3.0.1

3.0.0

• change: connect_minwait default now 0 (was 1.0 seconds in library API).
• change: force_binary auto-enabled when CHARSET is negotiated (RFC 2066) or LANG/CHARSET received via NEW_ENVIRON (RFC 1572). SyncTERM font detection also enables it unconditionally.
• change: --connect-timeout default changed from no limit to 10 seconds.
• change: --reverse-video CLI option from 2.4.0 was removed.
• change: CGA, EGA, and Amiga palettes removed from --colormatch; only vga is available at this time. ice_colors are now True by default.
• bugfix: read_some() in synchronous API (TelnetConnection and ServerConnection) blocked until EOF instead of returning available data. Now returns as soon as any data is available.
• new: TelnetSessionContext base class and writer.ctx attribute for per-connection session state. Subclass to add application-specific attributes (e.g. MUD client state).
• new: --ice-colors (default on) treats SGR 5 (blink) as bright background for proper 16-color BBS/ANSI art display.
• new: --typescript FILE records session output to a file, similar to the Unix script(1) command.
• new: shared TelnetProtocolBase mixin extracted from duplicated server and client protocol code.
• new: _atomic_json_write() and _BytesSafeEncoder helpers in _paths module for fingerprinting subsystem.
• enhancement: Microsoft Telnet (telnet.exe) compatibility refined — server now sends DO NEW_ENVIRON but excludes USER variable instead of skipping the option entirely, #24.
• enhancement: comprehensive pylint and mypy cleanup across the codebase.

Bugfix wcwidth dependency, #126

Full Changelog: 2.6.0...2.6.1

• new: TLS support (TELNETS). open_connection() accepts an ssl parameter (True, or an ssl.SSLContext). create_server() accepts an ssl parameter (ssl.SSLContext). New CLI options: --ssl, --ssl-cafile, --ssl-no-verify for telnetlib3-client; --ssl-certfile, --ssl-keyfile and --tls-auto for telnetlib3-server.
• new: the default server shell now displays Ready (secure: TLSv1.3). for TLS connections (the protocol version shown is negotiated dynamically).
• bugfix: telnetlib3-client now sets terminal mode to the server's preference via WILL ECHO and WILL SGA negotiation. Use --raw-mode to restore legacy raw mode for servers that don't negotiate.
• bugfix: telnetlib3-client declines MUD protocol options (GMCP, MSDP, MSSP, MSP, MXP, ZMP, AARDWOLF, ATCP) by default. Use --always-do or --always-will to opt in.
• bugfix: log output "staircase text" in raw terminal mode.
• bugfix: graceful EOF handling — connection close no longer prints a traceback.

Full Changelog: 2.5.0...2.6.0

• change: telnetlib3-client now defaults to raw terminal mode (no line buffering, no local echo), which is correct for most servers. Use --line-mode to restore line-buffered local-echo behavior.
• change: telnetlib3-server --pty-exec now defaults to raw PTY mode. Use --line-mode to restore cooked PTY mode with echo.
• change: connect_minwait default reduced to 0 across BaseClient, open_connection(), and telnetlib3-client. Negotiation continues asynchronously. Use --connect-minwait to restore a delay if needed, or use TelnetWriter.wait_for() in server or client shells to await a specific negotiation state.
• new: Color, keyboard input translation and --encoding support for ATASCII (ATARI ASCII) and PETSCII (Commodore ASCII).
• new: SyncTERM/CTerm font selection sequence detection (CSI Ps1 ; Ps2 SP D). Both telnetlib3-fingerprint and telnetlib3-client detect font switching and auto-switch encoding to the matching codec (e.g. font 36 = ATASCII, 32-35 = PETSCII, 0 = CP437). Explicit --encoding takes precedence.
• new: TRACE log level (5, below DEBUG) with hexdump style output for all sent and received bytes. Use --loglevel=trace.
• bugfix: robot_check() now uses a narrow character (space) instead of a wide Unicode character, allowing retro terminal emulators to pass.
• bugfix: ATASCII codec now maps bytes 0x0D and 0x0A to CR and LF instead of graphics characters, fixing garbled output when connecting to Atari BBS systems.
• bugfix: ATASCII codec normalizes CR and CRLF to the native ATASCII EOL (0x9B) during encoding, so the Return key works correctly.
• bugfix: PETSCII bare CR (0x0D) is now normalized to CRLF in raw terminal mode and to LF in telnetlib3-fingerprint banners.
• bugfix: telnetlib3-fingerprint re-encodes prompt responses for retro encodings so servers receive the correct EOL byte.
• bugfix: telnetlib3-fingerprint no longer crashes with LookupError when the server negotiates an unknown charset. Banner formatting falls back to latin-1.
• bugfix: TelnetClient.send_charset() normalises non-standard encoding names (iso-8859-02 to iso-8859-2, cp-1250 to cp1250, etc.).
• enhancement: telnetlib3-fingerprint responds more like a terminal and to more y/n prompts about colors, encoding, etc. to collect more banners for the https://bbs.modem.xyz/ project.
• enhancement: telnetlib3-fingerprint banner formatting uses surrogateescape error handler, preserving raw high bytes (e.g. CP437 art) as surrogates instead of replacing them with U+FFFD.

Full Changelog: https://github.com/jquast/telnetlib3/compare/2.4.0...2.5.0

• change: wcwidth is now a required dependency!
• bugfix: rare LINEMODE ACK loop with misbehaving servers that re-send unchanged MODE without ACK.
• bugfix: unknown IAC commands no longer raise ValueError; treated as data.
• bugfix: client no longer asserts on TTYPE IS from server.
• bugfix: request_forwardmask() only called on server side.
• enhancement: --banner-max-bytes option for telnetlib3-fingerprint; default raised from 1024 to 65536.
• enhancement: new --encoding=petscii and --encoding=atarist
• new: module telnetlib3.color_filter module — translates 16-color ANSI SGR codes to 24-bit RGB from hardware palettes (EGA, CGA, VGA, Amiga, xterm). Enabled by default. New client CLI options: --colormatch, --color-brightness, --color-contrast, --background-color, --reverse-video.
• new: function telnetlib3.mud.zmp_decode, mud.atcp_decode, and mud.aardwolf_decode decode functions for ZMP (option 93), ATCP (option 200), and Aardwolf (option 102) MUD protocols.
• new: methods telnetlib3.stream_writer.TelnetWriter.handle_zmp, handle_atcp, handle_aardwolf, handle_msp, and handle_mxp callbacks for receiving MUD extended protocol subnegotiations, with accumulated data stored in zmp_data, atcp_data, and aardwolf_data attributes.
• new: COM-PORT-OPTION (rfc 2217) subnegotiation parsing with comport_data attribute and new method telnetlib3.stream_writer.TelnetWriter.request_comport_signature.
• enhancement: telnetlib3-fingerprint now always probes extended MUD options (MSP, MXP, ZMP, AARDWOLF, ATCP) during server scans and captures ZMP, ATCP, Aardwolf, MXP, and COM-PORT data in session output.
• enhancement: telnetlib3-fingerprint smart prompt detection — auto-answers yes/no, color, UTF-8 menu, who, and help prompts.

New Contributors

• @shmup made their first contribution in https://github.com/jquast/telnetlib3/pull/116

Full Changelog: https://github.com/jquast/telnetlib3/compare/2.2.0...2.3.0

What's Changed

• telnetlib3-client --connect-timeout by @jquast in https://github.com/jquast/telnetlib3/pull/113
• MTTS fallback for CHARSET negotiation by @shmup in https://github.com/jquast/telnetlib3/pull/116
• Jq/some mud protocols by @jquast in https://github.com/jquast/telnetlib3/pull/114
• jq/telnetlib3 fingerprint server by @jquast in https://github.com/jquast/telnetlib3/pull/117
• telnetlib3-fingerprint host [port] CLI tool by @jquast in https://github.com/jquast/telnetlib3/pull/118
• bugfixes and enhancements from mud fingerprinting by @jquast in https://github.com/jquast/telnetlib3/pull/119
• Mud Improvements (round 2) by @jquast in https://github.com/jquast/telnetlib3/pull/120

New Contributors

• @shmup made their first contribution in https://github.com/jquast/telnetlib3/pull/116

Full Changelog: https://github.com/jquast/telnetlib3/compare/2.2.0...2.3.0

2.2.0

• bugfix: workaround for Microsoft Telnet client crash on SB NEW_ENVIRON SEND, #24. Server now defers DO NEW_ENVIRON until TTYPE cycling identifies the client, skipping it entirely for MS Telnet (ANSI/VT100).
• bugfix: in handling of LINEMODE FORWARDMASK command bytes.
• bugfix: SLC fingerprinting byte handling.
• bugfix: send IAC GA (Go-Ahead) after prompts when SGA is not negotiated. Fixes hanging for MUD clients like Mudlet. PTY shell uses a 500ms idle timer. Use --never-send-ga to suppress like old behavior.
• performance: with 'smarter' negotiation, default connect_maxwait reduced from 4.0s to 1.5s.
• performance: both client and server protocol data_received methods have approximately ~50x throughput improvement in bulk data transfers.
• new: Server class returned by create_server() with wait_for_client() method and clients property for tracking connected clients.
• new: TelnetWriter.wait_for() and wait_for_condition() methods for waiting on telnet option negotiation state.
• new: telnetlib3.sync module with blocking (non-asyncio) APIs: TelnetConnection for clients, BlockingTelnetServer for servers.
• new: pty_shell module and demonstrating telnetlib3-server --pty-exec CLI argument and related --pty-raw server CLI option for raw PTY mode, used by most programs that handle their own terminal I/O.
• new: guard_shells module with --robot-check and --pty-fork-limit CLI arguments for connection limiting and bot detection.
• new: fingerprinting module for telnet client identification and capability probing.
• new: --send-environ client CLI option to control which environment variables are sent via NEW_ENVIRON. Default no longer includes HOME or SHELL.

• bugfix: object has no attribute '_extra' by #100, #101

• bugfix: respond WILL CHARSET with DO CHARSET

Full Changelog: https://github.com/jquast/telnetlib3/compare/2.0.6...2.0.7

• bugfix: corrected CHARSET protocol client/server role behavior #59
• bugfix: allow --force-binary and --encoding to be combined to prevent long encoding failed after 4.00s delays in telnetlib3-server with non-compliant clients, #74
• bugfix: reduce telnetlib3-client connection delay, session begins as soon as TTYPE and either NEW_ENVIRON or CHARSET negotiation is completed.
• bugfix: remove 'NoneType' object has no attribute 'is_closing' message on some types of closed connections
• bugfix: further improve telnetlib3-client performance, capable of 11.2 Mbit/s or more.
• bugfix: more gracefully handle unsupported SB STATUS codes.
• feature: telnetlib3-client now negotiates terminal resize events.

Full Changelog: https://github.com/jquast/telnetlib3/compare/2.0.5...2.0.6

• feature: legacy telnetlib.py from Python 3.11 now redistributed, note change to project LICENSE.txt file.
• feature: Add TelnetReader.readuntil_pattern #92 by @agicy
• feature: Add TelnetWriter.wait_closed async method in response to #82.
• bugfix: README Examples do not work #81
• bugfix: TypeError: buf expected bytes, got <class 'str'> on client timeout in TelnetServer, #87
• bugfix: Performance issues with client protocol under heavy load, demonstrating server telnet://1984.ws now documented in README.
• bugfix: annoying socket.send() raised exception repeating warning, #89.
• bugfix: legacy use of get_event_loop, #85.
• document: about encoding and force_binary in response to #90
• feature: add tests to source distribution, #37

Full Changelog: https://github.com/jquast/telnetlib3/compare/2.0.4...2.0.5

• stop using setuptools library to get current software version

• bugfix: NameError: when debug=True is used with asyncio.run, #75

• bugfix: NameError: name 'sleep' is not defined in stream_writer.py

• bugfix: "write after close" is disregarded, caused many errors logged in socket.send()
• bugfix: in accessories.repr_mapping() about using shlex.quote on non-str, TypeError: expected string or bytes-like object, got 'int'
• bugfix: about fn_encoding using repr() on TelnetReaderUnicode
• bugfix: TelnetReader.is_closing() raises AttributeError
• deprecation: TelnetReader.close and TelnetReader.connection_closed emit warning, use at_eof() and feed_eof() instead.
• deprecation: the loop argument are is no longer accepted by TelnetReader.
• enhancement: Add Generic Mud Communication Protocol support :ghissue:63 by @gtaylor!
• change: TelnetReader and TelnetWriter no longer derive from asyncio.StreamReader and asyncio.StreamWriter, this fixes some TypeError in signatures and runtime

major

• Support Python 3.9, 3.10, 3.11. Drop Python 3.6 and earlier, All code and examples have been updated to the new-style PEP-492 syntax.
• the loop, event_loop, and log arguments are no longer accepted to any class initializers.
• The asyncio Future, TelnetServer.waiter_encoding, now receives only a boolean, rather than an instance of TelnetServer (self).
• This release has a known memory leak when using the _waiter_connected and _waiter_closed arguments to Client or Shell class initializers, please do not use them. A replacement "wait_for_negotiation" awaitable will be provided in a future release.

minor

• std. python telnetlib is no longer imported, its constants are extracted directly to avoid DeprecationWarning
• some changes in CI/tox about dropping/adding python support, etc.
• skip pexpect tests with py3.10 until I can find the time to also devote time to maintain that library to fix asyncio compatibility issues
• small fix in repr_mapping() to use shlex to make values containing spaces conditionally quoted
• small race condition fix for waiter_closed
• small race condition fix for repr(BaseClient) and Server, around "peername" and in get_extra_info()

• bugfix a NoneType error on EOF/Timeout, introduced in previous version 1.0.3, #51 by @zofy.

• bugfix circular reference between transport and protocol, #43 by @fried

Telnet client negotiates speed, defaults to 38400. Thanks @hughpyle #35

Python 3.7 compatibility (#33)

• Fix syntax errors in python 3.7 due to async being a reserved word
• Update tests to use await/async syntax
• drop python3.4 and custom coverage combining
• document 1.0.1 release, project status: seeking new owner :-)

After a year or more of refactoring, we release this new 1.0 API for the telnet protocol. This release prefers the shell(reader, writer) callback rather than the twisted-style subclassing of data_received in the previous version.

• bugfix: linemode MODE is now acknowledged. * bugfix: default stream handler sends 80 x 24 in cols x rows, not 24 x 80. * bugfix: waiter_closed future on client defaulted to wrong type. * bugfix: telnet shell (TelSh) no longer paints over final exception line.

• bugfix: cannot connect to IPv6 address as client.
• change: TelnetClient.CONNECT_DEFERED class attribute renamed DEFERRED. Default value changed to 50ms from 100ms.
• change: TelnetClient.waiter renamed to TelnetClient.waiter_closed.
• enhancement: TelnetClient.waiter_connected future added.
• add: functional tests using curl
• add: functional tests piping client and server together

• bugfix: cannot bind to IPv6 address, closes issue #5
• enhancement: Futures waiter_connected, and waiter_closed added to
• server.
• change: TelSh.feed_slc merged into TelSh.feed_byte as slc_function
• keyword.
• change: TelnetServer.CONNECT_DEFERED class attribute renamed DEFERRED.
• Default value changed to 50ms from 100ms.
• enhancement: Default TelnetServer.PROMPT_IMMEDIATELY = False ensures
• prompt is not displayed until negotiation is considered final. It is
• no longer "aggressive".
• enhancement: TelnetServer.pause_writing and resume_writing callback
• wired.
• enhancement: TelSh.pause_writing and resume_writing methods added.

minor bugfix that prevented installation for pip

• enhancement: various example programs were included in this release.

• Initial release.