(Unicode C++) 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.

Note: This example requires Chilkat v11.0.0 or greater.

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#include <CkCertW.h>
#include <CkPrivateKeyW.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkCertW cert;

    // Load from the PFX file
    const wchar_t *pfxFilename = L"/Users/chilkat/testData/pfx/chilkat_ssl_pwd_is_test.pfx";
    const wchar_t *pfxPassword = L"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 == false) {
        wprintf(L"%s\n",cert.lastErrorText());
        return;
    }

    // Get the private key...
    CkPrivateKeyW privKey;
    success = cert.GetPrivateKey(privKey);
    if (success == false) {
        wprintf(L"%s\n",cert.lastErrorText());
        return;
    }

    // Export to various formats:

    const wchar_t *password = L"secret";
    const wchar_t *path = 0;

    // PKCS8 Encrypted DER
    path = L"/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.der";
    success = privKey.SavePkcs8EncryptedFile(password,path);
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    // PKCS8 Encrypted PEM
    path = L"/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.pem";
    success = privKey.SavePkcs8EncryptedPemFile(password,path);
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    // PKCS8 Unencrypted DER
    path = L"/Users/chilkat/testData/privkeys/chilkat_pkcs8.der";
    success = privKey.SavePkcs8File(path);
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    // PKCS8 Unencrypted PEM
    path = L"/Users/chilkat/testData/privkeys/chilkat_pkcs8.pem";
    success = privKey.SavePkcs8PemFile(path);
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    //  RSA DER (unencrypted)
    path = L"/Users/chilkat/testData/privkeys/chilkat_rsa.der";
    success = privKey.SavePkcs1File(path);
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    // RSA PEM (unencrypted)
    path = L"/Users/chilkat/testData/privkeys/chilkat_rsa.pem";
    success = privKey.SavePemFile(path);
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    // XML (unencrypted)
    path = L"/Users/chilkat/testData/privkeys/chilkat.xml";
    success = privKey.SaveXmlFile(path);
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    wprintf(L"Private key exported to various formats.\n");
    }