SSH Public Key Authentication

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Demonstrates authenticating with an SSH server using public-key authentication. A private key is loaded into an SshKey object and passed to AuthenticatePk. The matching public key must already be installed on the server for the account.

Note: The private-key path is relative to the application's current working directory. Supply the path to your own key file.

Background: Public-key authentication is the standard for unattended and automated SSH: the private key never leaves the client, the server merely trusts the corresponding public key, and no reusable password crosses the wire. SshKey imports several formats — OpenSSH PEM keys via FromOpenSshPrivateKey and PuTTY .ppk files via FromPuttyPrivateKey — encrypted or not. For an encrypted key, set the Password property before importing. Note that LoadText is only a convenience for reading a text file into a string; it does not itself load the key.

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bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  Demonstrates authenticating with an SSH server using public-key authentication.  The matching
//  public key must already be installed on the SSH server for the account.

Chilkat.Ssh ssh = new Chilkat.Ssh();

//  Timeouts, in milliseconds.
ssh.ConnectTimeoutMs = 5000;
ssh.ReadTimeoutMs = 15000;

string hostname = "ssh.example.com";
int port = 22;
success = ssh.Connect(hostname,port);
if (success == false) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

//  LoadText is a convenience method that reads any text file into a string.  It does not itself
//  load the key.
Chilkat.SshKey key = new Chilkat.SshKey();
string privKeyText = key.LoadText("qa_data/my_private_key.pem");
if (key.LastMethodSuccess == false) {
    Debug.WriteLine(key.LastErrorText);
    return;
}

//  Import the private key.  Both OpenSSH and PuTTY formats are supported, encrypted or not.
//  This example loads an unencrypted OpenSSH-format key; for a PuTTY .ppk file, call
//  FromPuttyPrivateKey instead.  For an encrypted key, set key.Password before importing.
success = key.FromOpenSshPrivateKey(privKeyText);
if (success == false) {
    Debug.WriteLine(key.LastErrorText);
    return;
}

success = ssh.AuthenticatePk("mySshLogin",key);
if (success == false) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

Debug.WriteLine("Public-key authentication successful.");

ssh.Disconnect();