ssh

copying

scp copies files, but is primitive.
scp source destination
scp -p 10.1.1.5:/home/zero/downloads/file.txt .
scp Makefile.sh 10.1.1.4:Makefile.sh

Copying with ssh and pipes
Backing up a directory on my machine to the target machine. Let other be the directory.
tar zcvf - other | ssh zero@10.1.1.3 "cat > other.tgz"
Copy from the target machine to my machine.
ssh zero@10.1.1.3 "cat other.tgz" > other.tgz
Pipe it to decompress the file structure.
ssh zero@10.1.1.3 "cat other.tgz" | tar zpvxf -
Now copy the directory accross to the target machine.
tar zcvf - other | ssh zero@10.1.1.3 "cat > /cygdrive/e/other.tgz; cd /cygdrive/e/; cat other.tgz | tar zpvxf -; rm other.tgz"
I love ssh.
Here is copying the directory with scp.
scp -r other zero@10.1.1.3:/cygdrive/e/other

Copying directories with tar is recommended. On my local system tar needs to be called as it is at the command line.
tar -c cube | ssh 10.1.1.4 "cat > /home/zero/backup/cube.tar; cd /home/zero/backup/; cat cube.tar | tar xf -; rm cube.tar"

rsync -avz -e ssh zero@10.1.1.8:/home/zero/t3 .
Uses ssh to copy the directory. For example create a mirror by putting this into a cron job.

sftp

sftp is supported when the ssh deamon (service) is implemented.

Generally use sftp as it is much better for interactive use.
sftp zero@10.1.1.5

Local	Remote
lcd	cd
lls	ls
lmkdir	mkdir
lpwd	pwd
put	get

For a directory sftp refused to copy, so create an archive $tar -cv black.tar blacklagoon, then in sftp session get black.tar ., then in bash extract $tar -xf black.tar. I am having intermidant problems with some files unable to be expanded on windows box.

sshfs

Mount the remote file system. Turns the remote computer into a file server.

For example 1000Mbps ethernet at home with a fast linux computer (as a server) to watch my dvd's, simply mount the file system and run the files.

Mac

sshfs for Mac OS X
mkdir ~/p3 /Applications/sshfs/bin/mount_sshfs zero@10.1.1.8 ~/p3 umount ~/p3 umount -f ~/p3

ssh and Cygwin

On my home network I have a Linux box at 10.1.1.5 and a windows box with Cygwin installed with ssh. Logging into the Linux box from windows in a Cygwin terminal, $startx to start the X server.
ssh zero@10.1.1.5
For graphical programs the X11 display needs to be enabled.
ssh -Y zero@10.1.1.5
Windows does not support X11 so logging into the windows box from the Linux box is a command line. Instead I installed VNC client/server on the windows box( http://www.tightvnc.com ).
vncviewer 10.1.1.3 for windows box, then proped for password. This gives a remote login with graphics. Although dvd's and mpegs graphics were not displayed (black screen).

Command line script with ssh login.
ssh zero@10.1.1.5 "cd /tmp ; tar cf dvd.tar dvd"

To log into the windows box from the linux box the ssh deamon (service) sshd needs to be started on the windows box.
ssh-host-config net start sshd Answer the questions. Maybe I answered wrong because I do not yet have graphics from the windows box being sent to the linux box. (CYGWIN=ntsec tty).

To stop sshd on windows box,
cygrunsrv --stop sshd cygrunsrv --remove sshd Delete sshd user acount (Computer Management).

kill -HUP `cat /var/run/sshd.pid` to restart the ssh server.










automatic login


Let A and B be two machines.  To log in to A from B, 
Create a key pair on machine B.


ssh-keygen -t rsa -b 4000

return return return 


key pair in ~/.ssh/

Copy this file ~/.ssh/id_rsa.pub to machine A and append to
 
~/.ssh/authorized_keys





This is regarded as less secure than using a ssh agent.  On machine
 B the agent prompts for the password at the start of each session,
 then does the login authomatically thereafter.



What the agent does is decrypt the private key when in use and encrypt it
 when not in use.  Ofcourse the mechanics are fancier (store private key decrypted
 in cache only) so ~/.ssh/id_rsa on B is always encrypted by not being stored
 there but in the agent in encrypted state. Now you need to trust your agent.


To get similar in process security manually decrypt and encrypt ~/.ssh/id_rsa
 when using and not using the ssh login. 
 
 







Agent Forwarding Issue

Agent forwarding relies on obsification - that is hiding through complexity.
 Cryptography itself showed that this approach is useless as someone always comes along
 who can cut through the crap.


A better solution is to engineer your ssh login so that it is a sandbox and only
 provides the services necessary for its function. 


This is probably difficult to do, but is the only sane solution.

ssh

Intro

copying

sftp

sshfs

Mac

ssh and Cygwin

automatic login

Agent Forwarding Issue