C#

RSA Sign with PKCS8 Encrypted Key

See more RSA Examples

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature. C#

bool success = false;

// 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:
success = pkey.LoadPkcs8EncryptedFile("privateKey.key","myPassword");

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

// Import the private key into the RSA object:
success = rsa.UsePrivateKey(pkey);
if (success == false) {
    Debug.WriteLine(rsa.LastErrorText);
    return;
}

// Return the signature in hex
rsa.EncodingMode = "hex";

string strData = "This is the string to be signed.";

// Sign the string using the sha-1 hash algorithm.
// Other valid choices are "md2", "sha256", "sha384", "sha512",  and "md5".
string hexSig = rsa.SignStringENC(strData,"sha-1");

Debug.WriteLine(hexSig);