Unicode C

RSA Signature SHA256withRSA, iso-8859-1, base64

See more RSA Examples

RSA sign the iso-8859-1 byte representation of a string with SHA256withRSA, and return the signature in the base64 encoding. Unicode C

#include <C_CkPrivateKeyW.h>
#include <C_CkRsaW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPrivateKeyW privKey;
    HCkRsaW rsa;
    const wchar_t *originalData;
    const wchar_t *sigBase64;

    success = FALSE;

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

    //  This example will duplicate the following Java code:
    //  
    //  Signature sign = Signature.getInstance("SHA256withRSA");
    //  sign.initSign(privateKey);
    //  sign.update(original.getBytes(Charset.forName("ISO-8859-1")));
    //  
    //  ...
    //  byte[] resultado = sign.sign();
    //  sello = encodeByteArrayToBase64(resultado);
    //  

    //  Load an RSA private key for signing.
    //  You can load any format file.  This example loads a .pem, but you can provide path to any type of file holding a private key.
    privKey = CkPrivateKeyW_Create();
    success = CkPrivateKeyW_LoadAnyFormatFile(privKey,L"qa_data/pem/rsa_passwd.pem",L"passwd");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(privKey));
        CkPrivateKeyW_Dispose(privKey);
        return;
    }

    rsa = CkRsaW_Create();
    CkRsaW_UsePrivateKey(rsa,privKey);

    originalData = L"This is the string to be hashed an RSA signed.";

    //  Indicate that we want the iso-8859-1 byte representation of the string to be signed
    CkRsaW_putCharset(rsa,L"iso-8859-1");

    //  We want the RSA signature in base64 format
    CkRsaW_putEncodingMode(rsa,L"base64");

    sigBase64 = CkRsaW_signStringENC(rsa,originalData,L"sha256");
    wprintf(L"%s\n",sigBase64);


    CkPrivateKeyW_Dispose(privKey);
    CkRsaW_Dispose(rsa);

    }