Solved (?) SQL Developer 19.2: No more authentication methods available when using SSH Connections

When Oracle upgraded SQL Developer from 19.1 to 19.2 they updated some libraries. One of those updates meant that SSH keypairs that had been generated by PuttyGen didn’t work anymore and you should “Generate OpenSSH format ppk” (see Oracle Support Doc ID: 2575854.1)

However, when attempting to do so using PuttyGen it didn’t seem to work. Taking a step back, here was the situation in 19.1 or earlier:

  1. You had SQL Developer 19.1 running on your desktop and had used the SSH Hosts dialog to create an SSH connection pointing SQL Developer at the private key on your machine (typically, this is an id_rsa file).
  2. The server you are connecting to has the associated public key (typically, in the authorized_keys file associated with the account you were connecting to on the remote server.
  3. Everything worked as expected and you could connect to databases on the remote database server using the SSH connection.

After an upgrade to 19.2 (during which SQL Developer will ask you to import settings from a previous release), there is a chance that the private key that you previously had pointed to will no longer work.

My ‘used to work in 19.1 and earlier’ private key file looked like this:

Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC,abcdefghijklmnopqrstuvwxyz123456

If I opened that file in Putty Key Generator on a Windows 10 box, it said that it was already an OpenSSH SSH-2 Private key.Puttygen Notice

Since Oracle Support and others said that the key needed to be in OpenSSH format, one would assume that maybe you’d use the Conversion feature of Puttygen to convert the key…

Puttygen Conversion

Nope. No go.

After playing around for a long time I discovered the OpenSSH commands that are now built into Windows 10. After testing a million things, this is what actually worked:

C:\sshkeys> ssh-keygen -e -f id_rsa > id_rsa_for_sql_developer_19.2
Enter passphrase:

Once pointed at the id_rsa_for_sql_developer_19.2 file, SQL Developer happily prompted me for my (very long) passphrase and established a connection to my database.

Great! Problem solved.

However, and this is the strange thing that I don’t really understand… If you look at the contents of the generated file, you’ll see something like this:

Comment: "2048-bit RSA, converted by rich@ROTOR from OpenSSH"

Yep, that is what it looks like, a public key in SSH2 format (although I obviously obfuscated the above, for what reason, I do not know)…

Why an SSH2 Public Key works when you should have a private key (if I understand SSH connections correctly, and this sort of makes me feel like I don’t), I have no idea. But work it did, so I happily moved on.

As an aside, I did have an SR open with Oracle on this which I ended up closing myself, but I did ask them to update Doc ID: 2575854.1 with the above information before I closed it.

Happy SQL Developer-ing!


12 responses to “Solved (?) SQL Developer 19.2: No more authentication methods available when using SSH Connections

  • michael

    followed your note but cant seem to get sql developer to work on my mac , I keep on getting the same error more authentication methods available
    not really sure what else i can try , seems to work fine with 19.1
    i create the keys with ssh-keygen on the mac and then ran your command
    ssh-keygen -e -f id_rsa > id_rsa_for_sql_developer_19.2

    Still does not want to work 😦

    Thanks michael

  • Rich Soule


    I feel your pain. I believe that the SQL Developer team is going to support ppk keys again in SQL Developer 20.1.

    Right now I’m actually creating SSH tunnels using MobaXterm (there is a free version). MobaXterm has a great UI for building the tunnels and everything ‘just works’.

    I set the local port to be something like 11521, bounce through my SSH server on port 22 and then redirect to the database server on 1521. You have to add the key after you create the initial configuration for the tunnel.

    Here’s a link:


  • Rich Soule

    Ugh. Just realized that MobaXterm is PC only…

  • abhishekpatel0


    Did you get the solution for this.

    I am trying to connect to AWS hosted RDS database which is behind firewall using local port forwarding. But the pem key doesnot work giving the same error as you.

    I have just unzip SQL developer 19.4 and trying to configure. Do I need Oracle instant client or something? Or is this something else I can check?

  • Rich Soule


    Currently, my solution is to create a tunnel using a tool like MobaXterm and then just have SQL Developer use that tunnel instead of trying to use the SSH tunneling feature within SQL Developer. Some of my team members have rock solid SSH connections with SQL Developer, others, like myself, can’t keep the connections working.

    SSH tunnels can be created directly on the command line. Anton wrote this up quite well here:

  • Uwe M. Küchler

    Hi Rich,
    thank you for sharing this. It’s two years later now, I’m working with sqldev and wanted to give you and readers a short heads up:

    Yes, meanwhile sqldev accepts PuTTY’s .ppk format, again. BUT:
    While loading private key files from a shared (cloud) drive on Windows, I got the error message “no more authentication methods available”. This is probably due to SSH restrictions around access rights to key files. Moving the key file to a personal /local directory with stricter access limits solved the issue for me.
    Which is strange, because it worked with PuTTY in the first place. Looks like sqldev enforces SSh security practices more strictly.


  • Rich Soule

    Awesome! Thanks for that.

  • Lily Z

    Hi Über

    The issue is: my new DOH laptop uses SQL Developer 21, it always gives me connection error for access STC DB:
    “failed: org.apache.ssh.common.SshException: No more authentication methods available”

    I put the key in local directory and tried .ppk, also OpenSSH id_rsa converted from PuttyGen

    Any idea?

  • Rich Soule

    Are you using puttygen? This should now be working again with modern versions of SQL Developer (a new one just came out today).

  • JamieR

    I finally got it to work by swapping out the .ppk to a .pem format. I used the puttygen conversion tool to do the conversion.

  • Rich Soule

    Yeah, over the various versions the formats have changed, but it’s nice to know that the .pem format works now.

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