(Unicode C) Convert RSA Private Key to Public Key

Demonstrates how to get a public RSA key from a private RSA key.

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkPrivateKeyW.h>
#include <C_CkPublicKeyW.h>

void ChilkatSample(void)
    {
    HCkPrivateKeyW key;
    BOOL success;
    HCkPublicKeyW pubKey;
    BOOL bPreferPkcs1;

    key = CkPrivateKeyW_Create();

    // 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 = CkPrivateKeyW_LoadPemFile(key,L"qa_data/pem/VP_Private.pem");
    if (success != TRUE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(key));
        CkPrivateKeyW_Dispose(key);
        return;
    }

    // Step 2: Get the public key object from the private key object.
    pubKey = CkPrivateKeyW_GetPublicKey(key);
    if (CkPrivateKeyW_getLastMethodSuccess(key) != TRUE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(key));
        CkPrivateKeyW_Dispose(key);
        return;
    }

    // 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.
    bPreferPkcs1 = FALSE;
    success = CkPublicKeyW_SavePemFile(pubKey,bPreferPkcs1,L"qa_data/pem/VP_Public.pem");
    if (CkPublicKeyW_getLastMethodSuccess(pubKey) != TRUE) {
        wprintf(L"%s\n",CkPublicKeyW_lastErrorText(pubKey));
        CkPrivateKeyW_Dispose(key);
        return;
    }

    CkPublicKeyW_Dispose(pubKey);

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


    CkPrivateKeyW_Dispose(key);

    }