Unicode C++

Convert RSA Private Key to Public Key

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Demonstrates how to get a public RSA key from a private RSA key. Unicode C++

#include <CkPrivateKeyW.h>
#include <CkPublicKeyW.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkPrivateKeyW privKey;

    // Step 1: Load the private key from a source.
    // (Chilkat can load private keys from all types of formats, and from in-memory bytes or encoded strings.
    // see the online reference documentation for more options.)
    success = privKey.LoadPemFile(L"qa_data/pem/VP_Private.pem");
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    // Step 2: Get the public key object from the private key object.
    CkPublicKeyW pubKey;
    privKey.ToPublicKey(pubKey);

    // Step 3: Save the public key in a desired format. 
    // (Chilkat can load or save public and private keys in many different formats.  See
    // the online reference documentation for more options.)

    // Saves to a PKCS8 PEM file.
    bool bPreferPkcs1 = false;
    success = pubKey.SavePemFile(bPreferPkcs1,L"qa_data/pem/VP_Public.pem");
    if (pubKey.get_LastMethodSuccess() == false) {
        wprintf(L"%s\n",pubKey.lastErrorText());
        return;
    }

    wprintf(L"Extracted and saved public key from private key.\n");
    }