(.NET Core C#) Duplicate openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Demonstrates how to duplicate the creation of an RSA signature produced by this OpenSSL command:

openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

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

Chilkat.PrivateKey pkey = new Chilkat.PrivateKey();

// Load the private key from an RSA PEM file:
bool success = pkey.LoadPemFile("myKey.pem");

string pkeyXml;

// Get the private key in XML format:
pkeyXml = pkey.GetXml();

Chilkat.Rsa rsa = new Chilkat.Rsa();

// Import the private key into the RSA component:
success = rsa.ImportPrivateKey(pkeyXml);
if (success != true) {
    Debug.WriteLine(rsa.LastErrorText);
    return;
}

// OpenSSL uses BigEndian byte ordering:
rsa.LittleEndian = false;

// The resulting signature will be a Base64 string:
rsa.EncodingMode = "base64";

// For simplicity, we're not loading
// the data to be signed from a file.  We are instead simply
// using a literal string value.  
string strData = "This is the text to be signed.";

// Hash the input using MD5, and then sign the hash:
// Other valid hash algorithm choices are "md2" and "sha-1".
string base64Sig = rsa.SignStringENC(strData,"md5");

Debug.WriteLine(base64Sig);

Debug.WriteLine("Success!");