Getting "invalid private key file." error

[RahulVPol]

Hi,

I am new to this SFTP communication. I have received the Private_Keys.ppk file from my IT team, which is as follows,
PuTTY-User-Key-File-2: ssh-rsa
Encryption: aes256-cbc
Comment: imported-openssh-key
Public-Lines: 6
AAAAB3NzaC1yc2EAAAADAQABAAABAQCXVRQ8E0LnZ1aFepN0NaLaavip8cO+EJSp
29PBOB2pUCkua/3IXO7q3coziwdJOhPElL6vh3dHDYtuEqrXPhkEli9mruf20ZVj
vI5k4VtlQh5hzjwfgujmLpSWCA0OiH+i8f7y3J3e0PqIDD1E15ZShLWCpzB9YuXM
+Qq2eXs47QMJ9vUYlB6ZcMMftPBp7nQMDni+Z2IHFp4yq1XXo8wRu9pyoKG+j5T9
Vbb1voUCPwgLlcXETt3J3pzS/P+/lake7eTJytJXfhMCn2DovGBxnvHywILLPNaz
HE5FVMxc/ZI8IXqpbGKvY0CRqVNNlZWLRVntjL4IOuDZYMqI1cUJ
Private-Lines: 14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-MAC: d11ad00691481e1f6f4bedb11621574df1c93566

While creating PrivateKeyFile object,
privateKeyFile = new PrivateKeyFile(ppkfilepath);

I am getting following error,
Message: invalid private key file
Stack Trace: at Renci.SshNet.PrivateKeyFile.Open(Stream privateKey, String passPhrase)
at Renci.SshNet.PrivateKeyFile..ctor(String fileName, String passPhrase)
at Renci.SshNet.PrivateKeyFile..ctor(String fileName)
at TestApp.sftpProtocol.connectSftpServer(String strHost, Int32 iPort, String strUserName, String strPassword, Int32 iTimeout, String PPKFileName) in D:\Project\SFTP Demo\demo-master\sftp_demo\SFTP\TestApp\sftpProtocol.cs:line 36

Please advice.

Note: I am able to connect to the sftp using winscp.

[dnataraj]

As far as I know, this library does not support .ppk files for the private key - you need to convert your private key to an OpenSSH format (e.g PEM).

[rlipovski]

Hi,

I'm having a similiar issue. I've created a private key with ssh-keygen and stored in a oracle table. When the client.Connect() method is being called I get the same error. I tried the key with FileZilla and the connection was established succesfully.
Any help is appreciated. Thx!

[codegigd]

Hi
Any update on the above issue , I am also facing same and it is client provided key I can not modify it also.

[aengin]

Hi
i'm having the same problem. Any update ?

[timepassenger]

Putty-key is not supported now. You may convert putty-key to openssh-key using PUTTYGEN which installed with PUTTY, and openssh-key is working well.

[ganeshkamath89]

SSH.Net allows a format called "ssh.com".
Using the PuttyGen tool, you can use the option under
Conversions > Export ssh.com key

This is the only difference in the procedure to authenticate using credentials vs procedure to authenticate via private key.

[ravidyapa]

Hi,

Am having the same issue if I use .ppk key for authentication. It is working fine if I convert .ppk key to OpenSSH format.

[darkoperator]

Putty key format is not supported by the library, same for the newest format OpenSSH is using

…

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On Aug 9, 2019, at 9:55 AM, RaviDyapa ***@***.***> wrote: Hi, Am having the same issue if I use .ppk key for authentication. It is working fine if I convert .ppk key to OpenSSH format. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or mute the thread.

[drieseng]

OpenSSH format is now supported in the develop branch. For now, there's no support Putty private key files.

[ntimmerman]

Can I use openssl to generate the private key?

[Varorbc]

@Rob-Hague @scott-xu I'm really excited to see that SSH.NET now supports the PuTTY private key file format. I couldn't wait to try it out, but when I tried to load my key, I got an error saying 'MAC verification failed for PuTTY key file.' It works fine with PuTTYgen, though. If this issue could be fixed, that would be awesome!

[scott-xu]

@Varorbc Would you mind sharing me a PuTTY key file that can reproduce your issue? It doesn't have to be your secret private key.

[Varorbc]

@scott-xu passphrase is 123456

PuTTY-User-Key-File-2: ssh-rsa
Encryption: aes256-cbc
Comment: rsa-key-20241203
Public-Lines: 6
AAAAB3NzaC1yc2EAAAABJQAAAQEAhtAV5j4EG1nhAMcnAjNMOjGNQ/u1xfT8G7uq
Md6tw6fJZuZt2FvFj+RsokNkYEqxeTVhEeBWG2Q/kDNuNHRDxoKchaLnlfUHJuG8
uvuxYf3khkb5ljvs095WFfjOyb59ITjhWMz+ieaYk3K81Z3zborMqbISM4jgc2/v
vu1g4+8idHCcIEYG72MAqEdy6s7n8aBGo3uQuq80iwO7WhHnTAGTRkpONWqoNntQ
YUw3zTkTcedBTyCXqwRO/Q4OB6hTX49eluMdAqK+K+46dinWpK3LLT8NdYPUA//r
i+LoQ7rGyNoDei0eTqLkPz0CsP6AjhAQ6fQBP1Rv9RsiY0BUTQ==
Private-Lines: 14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-MAC: 8557ad1ab24bb00aea3b5affea5e08d1e83fb184

[scott-xu]

It works in my laptop using latest develop branch. I tried both .NET Framework 4.6.2 and .NET 9.0.

[Varorbc]

@scott-xu I found that the regular expression matched the value of the comment by an extra \r, and now I have fixed it. #1550