Export a Certificate's Private Key to Various Formats

Loads a digital certificate and private key from a PFX file (also known as PKCS#12) and exports the private key to various formats: (1) PKCS8 Encrypted, (2) PKCS8 Encrypted PEM, (3) PKCS8 unencrypted, (4) PKCS8 PEM unencrypted, (5) RSA DER unencrypted, (6) RSA PEM unencrypted, (7) XML.

Download: Chilkat .NET Assemblies

Chilkat.Cert cert = new Chilkat.Cert();

bool success;

//  Load from the PFX file
string pfxFilename;
pfxFilename = "/Users/chilkat/testData/pfx/chilkat_ssl_pwd_is_test.pfx";
string pfxPassword;
pfxPassword = "test";

//  A PFX typically contains certificates in the chain of authentication.
//  The Chilkat cert object will choose the certificate w/
//  private key farthest from the root authority cert.
//  To access all the certificates in a PFX, use the
//  Chilkat certificate store object instead.
success = cert.LoadPfxFile(pfxFilename,pfxPassword);
if (success != true) {
    textBox1.Text += cert.LastErrorText + "\r\n";
    return;
}

//  Get the private key...
Chilkat.PrivateKey privKey = null;
privKey = cert.ExportPrivateKey();
if (privKey == null ) {
    textBox1.Text += cert.LastErrorText + "\r\n";
    return;
}

//  Export to various formats:

string password;
password = "secret";
string path;

//  PKCS8 Encrypted DER
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.der";
success = privKey.SavePkcs8EncryptedFile(password,path);
if (success != true) {
    textBox1.Text += privKey.LastErrorText + "\r\n";

    return;
}

//  PKCS8 Encrypted PEM
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.pem";
success = privKey.SavePkcs8EncryptedPemFile(password,path);
if (success != true) {
    textBox1.Text += privKey.LastErrorText + "\r\n";

    return;
}

//  PKCS8 Unencrypted DER
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8.der";
success = privKey.SavePkcs8File(path);
if (success != true) {
    textBox1.Text += privKey.LastErrorText + "\r\n";

    return;
}

//  PKCS8 Unencrypted PEM
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8.pem";
success = privKey.SavePkcs8PemFile(path);
if (success != true) {
    textBox1.Text += privKey.LastErrorText + "\r\n";

    return;
}

//   RSA DER (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat_rsa.der";
success = privKey.SaveRsaDerFile(path);
if (success != true) {
    textBox1.Text += privKey.LastErrorText + "\r\n";

    return;
}

//  RSA PEM (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat_rsa.pem";
success = privKey.SaveRsaPemFile(path);
if (success != true) {
    textBox1.Text += privKey.LastErrorText + "\r\n";

    return;
}

//  XML (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat.xml";
success = privKey.SaveXmlFile(path);
if (success != true) {
    textBox1.Text += privKey.LastErrorText + "\r\n";

    return;
}

textBox1.Text += "Private key exported to all formats." + "\r\n";