Can't create a class instance of PrivateKeyFile

[orionplus]

I'm using version 2020.0.0-beta1.
Created the key pair with the command: ssh-keygen -t ecdsa -b 521
During the object creation
PrivateKeyFile keyFile = new PrivateKeyFile("c:..\id_ecdsa_private.key","passphrase")

I'm getting the error:
openssh key type: ecdsa-sha2-nistp521 is not supported
at Renci.SshNet.PrivateKeyFile.ParseOpenSshV1Key(Byte[] keyFileData, String passPhrase)
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 Onboarding.Services.SFTPService.d__7.MoveNext() in C:\Projects...\SFTPService.cs:line 65

The documentation says SSH.NET supports the following host key algorithms:
...
ecdsa-sha2-nistp521
...
Can anyone tell me please what is wrong?
Thanks!

[darinkes]

PrivateKey != HostKey.
You have to wait for this MR to be merged: #614

[orionplus]

Thanks for the prompt reply. What is the proper solution would be until that merge's done?

[darinkes]

You can create a key with the methods listed here: https://github.com/sshnet/SSH.NET#public-key-authentication.

ECDSA Keys are currently just supported in OpenSSL-Format. ssh-keygen generates them in OpenSSH-Format by default.
So a key generated with $ ssh-keygen -t ecdsa -b 521 -m pem should work.

Or you use ED25519 via: $ ssh-keygen -t ed25519

[orionplus]

@darinkes Thanks!

[hhyyrylainen]

With ecdsa keys I got the following error:

System.NotImplementedException: The method or operation is not implemented.
  at System.Security.Cryptography.ECDsa.Create (System.Security.Cryptography.ECParameters parameters) [0x00000] in <d9f4d70345484e55bbf6c1ef353f07c4>:0 
  at Renci.SshNet.Security.EcdsaKey.Import (System.String curve_oid, System.Byte[] publickey, System.Byte[] privatekey) [0x0007e] in <c7169cd606324a41b931acc40c516428>:0 
  at Renci.SshNet.Security.EcdsaKey..ctor (System.Byte[] data) [0x000f0] in <c7169cd606324a41b931acc40c516428>:0 
  at Renci.SshNet.PrivateKeyFile.Open (System.IO.Stream privateKey, System.String passPhrase) [0x00322] in <c7169cd606324a41b931acc40c516428>:0 
  at Renci.SshNet.PrivateKeyFile..ctor (System.String fileName, System.String passPhrase) [0x00023] in <c7169cd606324a41b931acc40c516428>:0 
  at Renci.SshNet.PrivateKeyFile..ctor (System.String fileName) [0x00000] in <c7169cd606324a41b931acc40c516428>:0 
  at Submission#30+<<Initialize>>d__0.MoveNext () [0x00008] in <e93e87d6d7854cc0919a6dcae8d7157b>:0 

That was in PEM format, and (without specifying -m pem to key generation), I got this error:

Renci.SshNet.Common.SshException: openssh key type: ecdsa-sha2-nistp521 is not supported
  + Renci.SshNet.PrivateKeyFile.ParseOpenSshV1Key(byte[], string)
  + Renci.SshNet.PrivateKeyFile.Open(System.IO.Stream, string)
  + Renci.SshNet.PrivateKeyFile..ctor(string, string)
  + Renci.SshNet.PrivateKeyFile..ctor(string)

Only ed25519 key seems to load correctly.

[darinkes]

The method or operation is not implemented.

That sounds like Mono, not .NET Correct?

https://github.com/mono/mono/blob/main/mcs/class/referencesource/System.Core/System/Security/Cryptography/ECDsa.cs#L31

ed25519 is done in SSH.NET, ECDsa requires .NET or netstandard functionality.

See the Readme, Mono is not supported. Also cause most of the Crypto we need just throws NotImplementedExceptions.

[hhyyrylainen]

I'm using .NET SDK (5.0.205) on Linux.

Edit: I used C# Interactive from Rider, where I'm not 100% sure it uses that version as I also have SDK version 3.1.117 installed.

[darinkes]

Weird. Cant see why official .NET should raise this exception.
In .NET Ecdsa.Create(ECParameters) is implemented since ages, see:

https://docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.ecdsa.create?view=net-5.0#System_Security_Cryptography_ECDsa_Create_System_Security_Cryptography_ECParameters_

Just seen this error with Mono so far. Using SSH.NET myself on various linux systems, all work fine ECDsa and .NET.

[scott-xu]

openssh key type: ecdsa-sha2-nistp521 is not supported

The issue should be fixed by #614

System.NotImplementedException: The method or operation is not implemented.

The issue should be fixed by #1461

I'm using .NET SDK (5.0.205) on Linux.

Edit: I used C# Interactive from Rider, where I'm not 100% sure it uses that version as I also have SDK version 3.1.117 installed.

On Mac OS X and Linux, JetBrains Rider defaults to Mono’s csharp. ¹

Footnotes

1. https://www.jetbrains.com/help/rider/CSHARP_Interactive.html ↩