Unicode C

RSA Encrypt Randomly Generated AES Key

See more RSA Examples

Demonstrates how to RSA encrypt a randomly generated AES key. Unicode C

#include <C_CkPrngW.h>
#include <C_CkBinDataW.h>
#include <C_CkCertW.h>
#include <C_CkPublicKeyW.h>
#include <C_CkRsaW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPrngW prng;
    HCkBinDataW bdAesKey;
    HCkCertW cert;
    HCkPublicKeyW pubKey;
    HCkRsaW rsa;
    const wchar_t *encryptedAesKey;

    success = FALSE;

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

    // First generate a 256-bit AES key (32 bytes).
    prng = CkPrngW_Create();
    bdAesKey = CkBinDataW_Create();
    success = CkPrngW_GenRandomBd(prng,32,bdAesKey);

    // Use a public key from a certificate for RSA encryption.
    cert = CkCertW_Create();

    success = CkCertW_LoadFromFile(cert,L"qa_data/pem/mf_public_rsa.pem");
    if (success == FALSE) {
        wprintf(L"%s\n",CkCertW_lastErrorText(cert));
        CkPrngW_Dispose(prng);
        CkBinDataW_Dispose(bdAesKey);
        CkCertW_Dispose(cert);
        return;
    }

    pubKey = CkPublicKeyW_Create();
    CkCertW_GetPublicKey(cert,pubKey);

    rsa = CkRsaW_Create();
    success = CkRsaW_UsePublicKey(rsa,pubKey);
    if (success == FALSE) {
        wprintf(L"%s\n",CkRsaW_lastErrorText(rsa));
        CkPrngW_Dispose(prng);
        CkBinDataW_Dispose(bdAesKey);
        CkCertW_Dispose(cert);
        CkPublicKeyW_Dispose(pubKey);
        CkRsaW_Dispose(rsa);
        return;
    }

    // RSA encrypt our 32-byte AES key.
    // The contents of bdAesKey are replaced with result of the RSA encryption.
    success = CkRsaW_EncryptBd(rsa,bdAesKey,FALSE);
    if (success == FALSE) {
        wprintf(L"%s\n",CkRsaW_lastErrorText(rsa));
        CkPrngW_Dispose(prng);
        CkBinDataW_Dispose(bdAesKey);
        CkCertW_Dispose(cert);
        CkPublicKeyW_Dispose(pubKey);
        CkRsaW_Dispose(rsa);
        return;
    }

    // Return the result as a base64 string
    encryptedAesKey = CkBinDataW_getEncoded(bdAesKey,L"base64");

    wprintf(L"encrypted AES key = %s\n",encryptedAesKey);


    CkPrngW_Dispose(prng);
    CkBinDataW_Dispose(bdAesKey);
    CkCertW_Dispose(cert);
    CkPublicKeyW_Dispose(pubKey);
    CkRsaW_Dispose(rsa);

    }