sshwrapper.sh

#!/bin/bash
# shellinabox ssh wrapper
# -s /:nobody:nogroup:/:/path/to/sshwrapper.sh

echo ""
echo "Example: user@host[:22]"
read -p "Connect to: " connstr;

if ! [[ "$connstr" =~ "@" ]]; then
        echo ""
        echo "Username is required."
        exit
fi

idx_at=`expr index $connstr "@"`
username=${connstr:0:idx_at-1}
port=22

if [[ "$connstr" =~ ":" ]]; then
        idx_colon=`expr index $connstr ":"`
        host=${connstr:idx_at:(idx_colon-idx_at-1)}
        port=${connstr:idx_colon}
else
        host=${connstr:idx_at}
fi

if [ -z "$host" ]; then
        echo ""
        echo "A hostname or ip address is required."
        exit
fi

if [[ -n ${port//[0-9]/} ]]; then
        echo ""
        echo "Port must be a number between 0 and 65535."
        exit
fi

echo ""
exec ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o "LogLevel ERROR" -p $port $username@$host