PuTTY

---=== PuTTY on AmigaOS4 ===---

--The Port

The  AmigaOS4  port  provides  the PuTTY 0.85 suite with a native ReAction
interface. Its configuration pages, menus and controls follow the original
Windows version as closely as native OS4 gadgets allow. The SSH protocols,
terminal  emulator, key formats and command-line tools retain the upstream
PuTTY implementation.

All eight programs are included: putty, puttytel, pterm, pageant, puttygen
plink, pscp and psftp:

- PuTTY provides the full connection frontend.
- PuTTYtel provides the non-SSH variant.
- Pterm is a local terminal with PuTTY's configuration options.
- Pageant manages authentication keys.
- PuTTYgen creates and converts keys.
- Plink, PSCP and PSFTP provide command-line tools.

--Runtime

The  programs  use  newlib  without an OpenSSL or AmiSSL dependency. PuTTY
provides   its   own  SSH  implementation,  cryptographic  algorithms  and
cryptographic random-number generator. Secure seed material comes directly
from  'timer.device''s  'UNIT_ENTROPY'  through 'TR_READENTROPY': the same
native  entropy  source  used  by  AmiSSL  on  AmigaOS4.  While  Fredrik's
(Salass00) SSHTerm uses libssh2 for SSH and AmiSSL for cryptography, PuTTY
provides both implementations itself.

The  binaries  are  built with '-O3' and a 1 MiB stack cookie. They do not
use  SJLJ exception handling or link GCC's generic emutls runtime. Instead
of  '-athread=native'  from  adtools, a private pthread/gthread-compatible
runtime  uses  native  Exec/DOS  workers, signals, mutexes, conditions and
task-specific storage.

The  minimum  version is dos.library 54.120, which fixes a lost-wakeup
race in 'WaitForChildExit'. The native worker runtime relies on this fix.

--ReAction Interface

All   windows   use   'window.class'  and  its  'WM_OPEN'/'WM_HANDLEINPUT'
lifecycle.

Layout,  buttons,  strings,  checkboxes,  radio  buttons,  choosers,  list
browsers  and  scrollers  are native ReAction objects. Colour modification
uses 'getcolor.gadget' with its native colour requester.

File and font selection use ASL requesters, messages and About windows use
'requester.class', and menu strips and submenus use native menu objects.

The Host Name field receives focus when configuration opens. Together with
the  underlined  keyboard  shortcuts on pushbuttons, this lets you enter a
host name and connect without using the mouse.

Change  Settings  remains  usable alongside the live terminal and does not
block terminal input.

--Terminal Engine and Rendering

The  terminal  is  PuTTY's  own emulator, with its escape-sequence parser,
character   translation,   Unicode   handling,  selection  and  compressed
scrollback.  Remote  sessions  are  not  rendered  by  'console.device' or
'texteditor.gadget':  the  frontend  draws  PuTTY's terminal cells through
'graphics.library' and 'diskfont.library'.

The  terminal  is  optimised  for  fast  rendering,  scrolling  and screen
updates.

Ordinary   fixed-width   text   is   batched   into   neighbouring   runs.
'graphics.library' 'Text()' draws each run into a reusable small RAM strip
using  'JAM2',  which  writes  the  foreground  and  background  together.
'BltBitMapTags' transfers the occupied run into the native backing bitmap.
Blank areas use 'RectFillColor'. Unicode outline glyphs use diskfont glyph
maps  and  'BltTemplate'.  The  changed  screen  region  is presented with
'BltBitMapRastPort', clipped to the window interior.

Small  scrolls move existing pixels and reuse terminal row data, then draw
exposed  or  changed rows. Unchanged rows avoid text-run assembly. Pending
scrollbar  positions  are  coalesced, redundant scroller notifications are
ignored,   and   manual   scrolling  does  not  wait  for  the  terminal's
incoming-output  repaint  delay. This path avoids a full-window RAM upload
or   video-memory   readback.  It  still  has  the  small  text-strip  and
backing-bitmap  blits  described  above.  Graphics  locks  cover  only the
operation that needs them and are released immediately.

The  terminal uses the system's default font and size unless overridden in
the  session  settings, and works best with a fixed-width font. Its native
window  has  a  thin  bottom  border  and  a  right-border  scroller, with
single-line mouse-wheel scrolling and a configurable scrollback buffer.

--Window Menu and Fullscreen

Use  RMB  over  the  terminal title, border or screen menu bar to open the
native  terminal  menu.  It  follows  PuTTY's original grouping, including
Special  Commands  and  Saved  Sessions  submenus,  Event  Log,  Duplicate
Session,  Change  Settings,  Copy  All  to Clipboard, Clear Scrollback and
Reset  Terminal.  RMB inside the terminal text area retains its configured
paste  behaviour.  Clipboard  exchange uses 'clipboard.device' to exchange
text with other Amiga applications.

Amiga-F  toggles  fullscreen. The  frontend  opens  a  private screen with 
SA_LikeWorkbench and a borderless window covering it, without a scrollbar.
The  same  connection  and  terminal  contents  remain  active.  Returning
restores the normal window and scroller. Alt-Enter also toggles fullscreen
when Full screen on Alt-Enter is enabled under Window / Behaviour.

--Pterm and the AmigaDOS Shell

Pterm  combines  the same PuTTY terminal engine and native renderer with a
real AmigaDOS Shell. The Shell executes 'S:Shell-Startup', so its aliases,
prompt  and  local  settings  are  applied  normally. Pterm interprets the
resulting  terminal  output;  it  does  not  reimplement  the Shell script
language.  An  explicit  command  supplied  with '-e' follows its separate
noninteractive startup path.

A native DOS-packet console provides input, output, waiting and cooked/raw
mode  handling.  Cooked  input  includes editing, history and file/command
completion.  Amiga-specific display controls are handled alongside PuTTY's
ANSI    terminal    parsing,   including   the   single-byte   CSI   form,
display-background selection and saved colour defaults.

Local  console  colours  are  obtained through 'ObtainConsoleData' and the
console preference API, with 'ENV:Sys/console.prefs' as a fallback. System
pens,  full  ANSI  colours,  faint  ANSI  colours  and  user  colours  are
respected. Local Amiga colours remain separate from the PuTTY palette used
by  a  remote  session.  Plink running inside pterm switches to the remote
terminal context and restores the local context on return.

Pterm  retains  PuTTY's  selection, clipboard, cursor, font and scrollback
controls.  While  another  command  owns  the  console, close requests are
ignored  and  the  command  remains usable. After the command exits, click
Close again to close the window.

--Plink, PSCP and PSFTP

Plink  is  useful  for  quick  command-line  connections, remote commands,
scripts  and  batch jobs without opening PuTTY's GUI. Its upstream options
also  support  tunnels, local/remote forwarding, dynamic SOCKS proxies and
connections  through  configured  proxies.  Use  '-t'  when an interactive
remote  terminal  is required; '-s' selects an SSH subsystem, not a normal
login shell.

When  run  from  a  native  Amiga  console,  Plink uses its Amiga terminal
context;  inside  pterm  it  can use the PuTTY/xterm context. A configured
terminal type or 'TERM' setting can override the default.

PSCP  provides  command-line  file  copying  using  SFTP by default or the
legacy SCP protocol with '-scp'.

PSFTP  provides an interactive SFTP prompt and batch files with '-b'. SFTP
is an SSH file-transfer protocol, not FTP.

--PuTTYgen

PuTTYgen has a full native ReAction GUI following the Windows application:
its  initial  view, mouse-entropy collection view and generated/loaded-key
view  show the corresponding controls at the appropriate stage. File, Key,
Conversions and Help menus retain the original operations and terminology.

Move the mouse over the blank collection area after clicking Generate. The
collection  progress  advances with mouse input and pauses when that input
stops.  The  following  progress  phase is the actual key computation in a
native  worker.  Secure  OS  entropy is also used. The key algorithms, PPK
formats,  encryption  and  conversions come from upstream PuTTY. Encrypted
RSA,  Ed25519  and  ECDSA key files have been checked with upstream tools.
This  is  the  Windows-style  GUI program with its applicable command-line
interface, rather than the Unix batch-only frontend.

--Pageant and Connection Sharing

Pageant  is a separate native key-agent program, as in the original suite.
Add  PuTTY  private  key  files  through Add Key or run 'pageant key.ppk'.
Unlock  encrypted  keys  once;  PuTTY  and the command-line tools can then
request  authentication  through  the agent. The server must authorize the
matching  public  key,  and  Attempt  authentication using Pageant must be
enabled.  Remove  Key,  Remove  All  and quitting the agent discard loaded
keys.  Native Exec message ports provide local communication without a TCP
listener.

SSH  connection  sharing  uses  native  local  IPC  too.  Enable Share SSH
connections  if  possible under Connection / SSH before connecting, or use
'-share'.  Duplicate  Session  can  reuse the authenticated connection for
another  shell without another login. Pageant is not required for sharing.
Closing  the upstream window disconnects its shared sessions; exiting only
its remote shell keeps those sessions running until the last one ends.

--Settings, Paths and Help

Saved   settings,   host   keys   and   random-seed   data   are  kept  in
'PROGDIR:config',   or  in  the  drawer  selected  by  'PUTTYDIR'.  Serial
connections  use  device/unit  names  such  as  'serial.device/0'.  Native
terminal printing writes through 'PRT:'.

Local proxy commands are executed through the AmigaDOS Shell.

Help  opens  this  file,  'PROGDIR:docs/PuTTY.guide'.  The manual chapters
retain  the  upstream text, converted from 'putty.chm' to AmigaGuide, with
this AmigaOS4 chapter added.

--Network Support and Remaining Platform Limits

Networking  uses  'bsdsocket.library'.  This build supports IPv4 only;IPv6
and  GSSAPI support, including Kerberos single sign-on through GSSAPI, are
disabled. Password and public-key SSH  authentication, connection sharing,
proxies, TCP port forwarding and SFTP/SCP remain available.

Windows  process-ACL  restrictions  and Unix-specific facilities such as X
resources  and  utmp  login  accounting  do  not  apply  to this port. X11
forwarding remains available to an X server reachable over TCP/IP.

Pterm does not implement every direct 'console.device' operation. Programs
requiring such operations may not work correctly.

The  serial  backend  supports one or two stop bits, with no flow control,
XON/XOFF  or RTS/CTS, subject to driver and hardware support. The standard
'serial.device'  interface  does  not expose settings for 1.5 stop bits or
DSR/DTR flow control, so these modes are not implemented.

--Bugs

The  suite  has  been  tested  with  bidirectional serial connections, SSH
connections  to different servers, Telnet connections to routers and proxy
configurations. Bugs are still possible. Please report them at:
https://github.com/kas1e/putty/

--Credits

PuTTY is by Simon Tatham and the PuTTY contributors.

AmigaOS4 port is by Roman "kas1e" Kargin.

09/11/2026