.NET Core C#

RSA Hash Binary Data and Sign (and Verify)

See more RSA Examples

Demonstrates how to sign the hash of binary data. Also demonstrates how to verify the RSA signature. .NET Core C#

bool success = false;

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

// Load an RSA private key for signing.
Chilkat.PrivateKey privKey = new Chilkat.PrivateKey();
success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd");
if (success == false) {
    Debug.WriteLine(privKey.LastErrorText);
    return;
}

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

// We have some binary data (in hex) to sign
string originalData = "0102030405060708090A";
Chilkat.BinData bdData = new Chilkat.BinData();
bdData.AppendEncoded(originalData,"hex");

// Hash (SHA-256) and sign the hash:
Chilkat.BinData bdSignature = new Chilkat.BinData();
success = rsa.SignBd(bdData,"sha256",bdSignature);
if (success == false) {
    Debug.WriteLine(rsa.LastErrorText);
    return;
}

// Show the RSA signature in base64
Debug.WriteLine(bdSignature.GetEncoded("base64"));

// ------------------------------------------
// Get the public key from the private key
Chilkat.PublicKey pubKey = new Chilkat.PublicKey();
privKey.ToPublicKey(pubKey);

// Verify the signature..
Chilkat.Rsa rsa2 = new Chilkat.Rsa();
rsa2.UsePublicKey(pubKey);

bool bVerified = rsa2.VerifyBd(bdData,"sha256",bdSignature);
Debug.WriteLine("signature verified: " + Convert.ToString(bVerified));