BebboSSH

WHAT IS THIS?

BebboSSH is an SSH2 implementation for Amiga systems by Stefan "Bebbo"
Franke. This archive is its port to
AROS aarch64 (the Raspberry Pi port of AROS).
With it you can log in to an AROS machine from any SSH client, run
commands, and copy files with scp and sftp; the native clients connect
from AROS to other SSH servers. The original 68k version is
comm/net/bebbossh.lha;
the AROS i386 build is comm/net/bebbossh.i386-aros.lha,
the AROS x86_64 build is comm/net/bebbossh.x86_64-aros.lha.

PROGRAMS

  bebbosshd       SSH2 server: remote commands, SFTP, SCP, TCP port
                  forwarding (direct-tcpip), password and public-key login
  bebbossh        SSH2 client, with -L local port forwarding
  bebboscp        SCP client
  bebbosshkeygen  Ed25519 key generator

Algorithms: curve25519-sha256 key exchange, ssh-ed25519 host and user
keys, aes128-gcm()openssh.com and chacha20-poly1305()openssh.com ciphers.

REQUIREMENTS

- AROS for the Raspberry Pi, aarch64. Tested on a Raspberry Pi 400
  with the raspi-aarch64 build of 2026-09-12 and its Ethernet.
- A configured TCP/IP stack (AROSTCP, bsdsocket.library).
- No extra libraries: the crypto code is linked into each program.

CONTENTS

  BebboSSH/bebbosshd, bebbossh, bebboscp, bebbosshkeygen
  BebboSSH/sshd_config.example, passwd.example
  BebboSSH/README.AROS.txt   install and configuration guide
  BebboSSH/README.md, AROS_PORTING.md, docs/, scripts/
  BebboSSH/COPYING, LICENSE  license texts (GNU GPL v3)
  BebboSSH/SHA256SUMS        checksums of the files above

INSTALLATION

1. Extract the archive to the system volume, SYS:. On the Pi image
   SYS: is a FAT volume: protect reports an error there, which can be
   ignored, the programs still run.
2. In an AROS Shell, create the configuration and a host key. The
   throwaway key first creates the random seed (see README.AROS.txt,
   Random Numbers):

     cd SYS:BebboSSH
     copy sshd_config.example sshd_config
     copy passwd.example passwd
     bebbosshkeygen -f T:seed_key
     delete T:seed_key T:seed_key.pub
     bebbosshkeygen -f ssh_host_ed25519_key

3. Edit passwd: one "username password" pair per line. The test/test
   entry of the example is for a first test only; replace it.
4. Start the server:

     stack 262144
     bebbosshd

5. From another machine: ssh username()<address of the AROS machine>

To start the network and the server at boot, AROSTCP must start at
boot (ENVARC:AROSTCP/AutoRun containing True); then start the server
from S:User-Startup a few seconds later. The scripts used on the Pi
400 are in BebboSSH/docs/AROS_AARCH64_RELEASE.md (Autostart).

To call the clients from anywhere, copy bebbossh, bebboscp and
bebbosshkeygen to C:. Keep bebbosshd in its own directory: the example
configuration finds its files through PROGDIR:.

CONFIGURATION

bebbosshd reads ENVARC:ssh/sshd_config if it exists, otherwise
PROGDIR:sshd_config. The main directives (the example sets all but
Ciphers and AllowTcpForwarding, which keep their defaults):

  Port 22                 TCP port
  ListenAddress 0.0.0.0   address to listen on (0.0.0.0 = all)
  HostKey PROGDIR:ssh_host_ed25519_key
  Passwords PROGDIR:passwd
  HomeDir DH0:            start directory of commands and SFTP
  Stack 262144            stack of command tasks (default 1 MiB)
  DebugLevel 1            log level: 0 none to 8 ultra, or a name such
                          as error or debug
  SendNoop some           keepalive messages to idle sessions
  Ciphers aes128-gcm()openssh.com,chacha20-poly1305()openssh.com
                          ciphers offered (both by default)
  AllowTcpForwarding yes  direct-tcpip forwarding (ssh -L); no refuses it

Command-line options override the file: -p port, -A password file,
-K host key, -H home directory, -v log level (for example -v5).
Public-key login reads ENVARC:.ssh/authorized_keys (OpenSSH format,
one key per line). README.AROS.txt describes every file in detail.

USAGE

From a PC with OpenSSH:

  ssh user()aros-host version
  scp file.txt user()aros-host:SYS:
  sftp user()aros-host

From AROS:

  bebbossh user()host
  bebbossh -i SYS:keys/id_ed25519 user()host command
  bebbossh -L 8080:localhost:80 user()host
  bebboscp localfile user()host:remotefile
  bebbosshkeygen -f SYS:keys/id_ed25519

The first connection to a host asks, in a console window, whether to
trust its key: answer yes. The key is then kept in
ENVARC:.ssh/known_hosts. Without a console (for example in a remote
command) an unknown host is refused. A host whose key differs from the
stored one is always refused with a warning; if the change is
expected, remove its line from known_hosts.

KNOWN LIMITS

- No full interactive PTY programs: the interactive shell runs simple
  commands, and programs that read their input are rejected with exit
  status 2.
- No redirection or pipes (>, <, |) in remote commands.
- A command typed in an interactive session runs inside the server:
  other connections wait until it ends, and Ctrl-C does not stop it.
  Run long commands as "ssh host command", which runs them in a
  separate task.
- A remote command still running after 30 seconds gets a timeout
  notice and exit status 124, but it keeps running until it ends.
- On the Raspberry Pi 400, a server logging at debug level (-v5) into
  a console window during heavy transfers froze the system. Keep the
  default log level there.
- OpenSSH "put -p" sets the file time before it closes the file, and
  AROS updates the date on close, so that time is not kept.
- passwd.example contains a test password: change it.

WHAT IS NEW IN 1.0.7

- 1.0.6 refused password logins from clients that send SSH_MSG_IGNORE
  before the password, as PuTTY, plink, pscp, psftp and WinSCP do;
  1.0.7 accepts them. Updating is recommended.
- Keys and session secrets come from a SHA-512 entropy pool with a seed
  file, ENVARC:.ssh/random_seed, ported from bebbossh 1.46.1 by Matthias
  Muench. README.AROS.txt (Random Numbers) explains the seed.
- More bounds checks in the SFTP server, in public-key login and in the
  clients; bebbosshkeygen checks its writes and wipes its secrets.
- bebbosshkeygen shows its questions at a console and waits for the
  answer; it took the command line as its first answer.
- AllowTcpForwarding off (or any unknown value) refuses forwarding;
  1.0.6 refused it only with no, false and 0.

TESTED

On a Raspberry Pi 400 with the programs of this archive: OpenSSH ssh,
scp and sftp; 100 logins in a row; 80 file transfers without pauses;
4 MiB copies with both ciphers; uploads up to 16 MiB; two servers at
once; connections dropped during commands; Ctrl-C on an idle server,
during a command and while a dropped connection's command still
runs, each followed by a restart; the login and host key checks of
this release, also a password login as PuTTY sends it; the native
clients over loopback.

SOURCE AND LICENSE

GNU GPL v3 or later (see COPYING). Source of this release:
  https://github.com/kaffeine1/bebbossh-aros/tree/v1.0.7-aros-aarch64
Original BebboSSH: https://franke.ms/git/bebbo/bebbossh
Bug reports: https://github.com/kaffeine1/bebbossh-aros/issues

Port by Michele Dipace <michele.dipace()kaffeine.net>.