java - JSCH - Invalid private key

Question

I am running JDK 1.7 & Windows 7 using netbeans 7.2 I have generated a SSH private & public key pair (SSH2-2048 bits) using putty-keygen. I do not have any password for private key. I am now trying to connect to one of the host machine using SFTP. But when I pass private key (ppk) to set Identity, code is returning invalid private key error. I used same private key in WinSCP to connect to same host & it is working fine. Kindly help me to resolve the error. Here is my code:

JSch jsch = new JSch();

Session session = null;

try {

    jsch.addIdentity("D:\TEMP\key.ppk");

    session = jsch.getSession("tiabscp", "ssiw.support.qvalent.com", 22);
    session.setConfig("StrictHostKeyChecking", "no");
    //session.setPassword("");
    session.connect();
    Channel channel = session.openChannel("sftp");
    System.out.println("Getting connected");
    channel.connect();
    System.out.println("connected successfully");
    ChannelSftp sftpChannel = (ChannelSftp) channel;
    sftpChannel.get("remotefile.txt", "localfile.txt");
    sftpChannel.exit();
    session.disconnect();
}catch (JSchException e) {

    e.printStackTrace();

}catch (SftpException e) {

    e.printStackTrace();
}

Answer 1

I guess that your key is not in OpenSSH key file format. JSch expects the private key to be in OpenSSH format.

You can use PuTTYgen to convert your private key to work with OpenSSH by following the steps described here:

1. Press Load and select the Private Key that was created with PuTTYgen.
2. Enter the passphrase to load the key.
3. From the Conversions menu select export OpenSSH key
4. Save the private key.