SSH Authenticate with Secure Strings

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Demonstrates SSH password authentication using SecureString objects, with the credentials read from an encrypted JSON config file and decrypted directly into secure strings rather than being hard-coded in source.

Background: This shows the shape of a genuinely careful credential flow: secrets live outside the source in encrypted form, and are decrypted straight into a SecureString so a plaintext copy never sits in an ordinary string. A SecureString keeps the value encrypted in memory under a randomly generated session key. In production the decryption key itself would come from a secure source — a key vault, an OS keystore, or the environment — rather than being a literal as shown here for illustration.

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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 SSH password authentication using SecureString objects, with the credentials
//  read from an encrypted config file rather than hard-coded in source.

//  Imagine the login and password were previously encrypted and saved in a JSON config file:
//  {
//    "ssh_login": "2+qylFfC56Ck7OQQt/U2/w==",
//    "ssh_password": "5neIq9Jmn0E3p71N6Yc8TA=="
//  }
Chilkat.JsonObject json = new Chilkat.JsonObject();
success = json.LoadFile("qa_data/passwords/ssh.json");
if (success == false) {
    Debug.WriteLine(json.LastErrorText);
    return;
}

//  These are the encryption settings used when the credentials were encrypted.  In a real
//  application the key would come from a secure source, not a literal.
Chilkat.Crypt2 crypt = new Chilkat.Crypt2();
crypt.CryptAlgorithm = "aes";
crypt.CipherMode = "cbc";
crypt.KeyLength = 128;
crypt.SetEncodedKey("000102030405060708090A0B0C0D0E0F","hex");
crypt.SetEncodedIV("000102030405060708090A0B0C0D0E0F","hex");
crypt.EncodingMode = "base64";

//  Decrypt directly into SecureString objects.  The values remain encrypted in memory, now
//  under a randomly generated session key.
Chilkat.SecureString ssLogin = new Chilkat.SecureString();
Chilkat.SecureString ssPassword = new Chilkat.SecureString();
crypt.DecryptSecureENC(json.StringOf("ssh_login"),ssLogin);
crypt.DecryptSecureENC(json.StringOf("ssh_password"),ssPassword);

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

//  Authenticate using the secure strings.
success = ssh.AuthenticateSecPw(ssLogin,ssPassword);
if (success == false) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

Debug.WriteLine("SSH authentication successful.");

ssh.Disconnect();