Unicode C++

RSA Sign an Encoded Hash

See more RSA Examples

Demonstrates signing a hash (e.g., SHA256) provided as an encoded string (e.g., base64 or hex). Unicode C++

#include <CkCertW.h>
#include <CkBinDataW.h>
#include <CkRsaW.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
    //  this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

    //  Chilkat automatically detects and determines the way in which the HSM is used,
    //  which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

    CkCertW cert;

    //  Set the token/smartcard PIN prior to loading.
    cert.put_SmartCardPin(L"123456");

    //  Specify the certificate by its common name.
    success = cert.LoadFromSmartcard(L"cn=chilkat-rsa-2048");
    if (success == false) {
        wprintf(L"%s\n",cert.lastErrorText());
        return;
    }

    wprintf(L"Signing with the private key for this cert: %s\n",cert.subjectCN());

    //  Create data to be hashed and signed.
    CkBinDataW bd;
    int i;
    for (i = 0; i <= 100; i++) {
        bd.AppendEncoded(L"000102030405060708090A0B0C0D0E0F",L"hex");
    }

    CkRsaW rsa;

    //  Use the certificate's private key for signing.
    success = rsa.SetX509Cert(cert,true);
    if (success == false) {
        wprintf(L"%s\n",rsa.lastErrorText());
        return;
    }

    //  We'll first compute the hash and then pass the encoded hash to be signed.
    const wchar_t *sha256_base64 = bd.getHash(L"sha256",L"base64");
    wprintf(L"sha256 hash in base64 format: %s\n",sha256_base64);

    //  Pass in the base64 hash and return a base64 signature.
    rsa.put_EncodingMode(L"base64");
    const wchar_t *rsaSig_base64 = rsa.signHashENC(sha256_base64,L"sha256");
    if (success == false) {
        wprintf(L"%s\n",rsa.lastErrorText());
        return;
    }

    wprintf(L"RSA signature as base64: %s\n",rsaSig_base64);
    }