Ssh with private key error ssh: Exited: String too long

[simtcrom]

Hello,

I have a remote linux server where ssh keys are setup.
The private key used for the remote server in ppk format (putty). I ran below command to convert it ,

puttygen puttykey.ppk -O private-openssh -o id_rsa

Then copied the id_rsa file to openwrt system, And trying to connect to remote server using command,

ssh -i id_rsa  pi@192.168.0.195 -p xxx

Getting error,
ssh: Exited: String too long

Any idea how to fix it?

[simtcrom]

I solved the issue by doing below,
openwrt uses dropbear ssh. Which support different format for ssh keys.

on remote server run,
sudo apt install putty-tools
upload puttykey.ppk to remoteserver
run below to convert ppk to openssh format

puttygen puttykey.ppk -O private-openssh -o id_rsa
chmod 600 id_rsa_dropbear

run below to remove the password from id_rsa private key

ssh-keygen -p -m PEM -f id_rsa
chmod 600 id_rsa_dropbear

copy id_rsa to openwrt
install dropbearconvert on openwrt by

opkg install dropbearconvert

run below command to convert id_rsa to dropbear format

dropbearconvert openssh dropbear id_rsa id_rsa_dropbear
chmod 600 id_rsa_dropbear

Finally,

ssh -i id_rsa_dropbear pi@192.168.0.195 -p xxx