Copy remote logfile over 2 hop SSH sessions, without the need for keying passwords

Question

I wish to get logfile from a remotePC via a gatewayServer to my local PC without keying passwords. The gateway server used acctA@gatewayServer. The remote PC used acctB@remotePC.

I have setup the SSH private/public keys on both gateway & remote.

From my local PC, I could SSH into remotePC directly via 2 hops without the need to key the 2 accounts' passwords, using: ssh acctA@gatewayServer -t ssh acctB@remotePC

But when I use SCP with ProxyCommand, it ask me for the password for acctB. Why?

scp -Cp -o "ProxyCommand ssh -q acctA@gateway -W remotePC:22" acctB@remotePC:/opt/logpath/log1.tgz log01.tgz

Advance thanks & appreciation to anyone who can advice.

Answer 1

The easiest thing is to introduce these lines in your .ssh/config file:

  Host remotePC
  User          acctB
  HostName      remotePC
  ProxyCommand  ssh AcctA@gatewayServer nc %h %p 2> /dev/null

which you can then use to connect or copy files simply by means of:

  ssh remotePC
  scp acctB@remotePC:/home/AcctB/somefile .

For this to work, you nee the netcat (nc) command installed on the gatewayServer.

If you really insist on a one-liner (but I can never remember all this stuff), here you go:

ssh -o "ProxyCommand ssh acctA@gatewayServer nc -w 1 %h 22" acctB@remotePC

and likewise for scp.