C#

RSA Signature with Certificate's Private Key from PFX

See more RSA Examples

Demonstrates how to use a certificate's private key from a PFX file to create an RSA signature. C#

bool success = false;

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

// Create an instance of a certificate store object, load a PFX file,
// locate the certificate we need, and use it for signing.
// (a PFX file may contain more than one certificate.)
Chilkat.CertStore certStore = new Chilkat.CertStore();

// The 1st argument is the filename, the 2nd arg is the 
// PFX file's password:
success = certStore.LoadPfxFile("chilkat.pfx","test");
if (success == false) {
    Debug.WriteLine(certStore.LastErrorText);
    return;
}

// Find the certificate by the subject common name:
Chilkat.JsonObject jsonCN = new Chilkat.JsonObject();
jsonCN.UpdateString("CN","cert common name");

Chilkat.Cert cert = new Chilkat.Cert();
success = certStore.FindCert(jsonCN,cert);
if (success == false) {
    Debug.WriteLine(certStore.LastErrorText);
    return;
}

Chilkat.PrivateKey privKey = new Chilkat.PrivateKey();
success = cert.GetPrivateKey(privKey);
if (success == false) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

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

success = rsa.UsePrivateKey(privKey);
if (success == false) {
    Debug.WriteLine(rsa.LastErrorText);
    return;
}

// Encode the signature as a hex string
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 "sha-256", "md2" and "md5".
string hexSig = rsa.SignStringENC(strData,"sha-1");

Debug.WriteLine(hexSig);

Debug.WriteLine("Success!");