RSA Signature with Certificate's Private Key from PFX

Demonstrates how to use a certificate's private key from a PFX file to create an RSA signature.

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MS Windows Visual C/C++ Libraries

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MAC OS X C/C++ Libraries

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C++ Builder Libraries

#include <C_CkCertStore.h>
#include <C_CkCert.h>
#include <C_CkPrivateKey.h>
#include <C_CkRsa.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCertStore certStore;
    HCkCert cert;
    HCkPrivateKey pkey;
    const char * pkeyXml;
    HCkRsa rsa;
    const char * strData;
    const char * hexSig;



    //  Create an instance of a certificate store object, load a PFX file,
    //  locate the certificate we need, and use it for signing.
    //  (a PFX file may contain more than one certificate.)
    certStore = CkCertStore_Create();

    //  The 1st argument is the filename, the 2nd arg is the
    //  PFX file's password:
    success = CkCertStore_LoadPfxFile(certStore,"chilkat.pfx","test");
    if (success != TRUE) {
        printf("%s\n",CkCertStore_lastErrorText(certStore));
        return;
    }

    cert = CkCertStore_FindCertBySubject(certStore,"Chilkat Software, Inc.");
    if (cert == 0 ) {
        printf("%s\n",CkCertStore_lastErrorText(certStore));
        return;
    }

    pkey = CkCert_ExportPrivateKey(cert);
    if (pkey == 0 ) {
        printf("%s\n",CkCert_lastErrorText(cert));
        return;
    }

    //  Get the private key in XML format:
    pkeyXml = CkPrivateKey_getXml(pkey);
    CkPrivateKey_Dispose(pkey);

    rsa = CkRsa_Create();

    //  Any string argument automatically begins the 30-day trial.

    success = CkRsa_UnlockComponent(rsa,"30-day trial");
    if (success != TRUE) {
        printf("RSA component unlock failed\n");
        return;
    }

    //  Import the private key into the RSA component:
    success = CkRsa_ImportPrivateKey(rsa,pkeyXml);
    if (success != TRUE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        return;
    }

    //  This example will sign a string, and receive the signature
    //  in a hex-encoded string.  Therefore, set the encoding mode
    //  to "hex":
    CkRsa_putEncodingMode(rsa,"hex");

    //  If some other non-Chilkat application or web service is going to be verifying
    //  the signature, it is important to match the byte-ordering.
    //  The LittleEndian property may be set to TRUE
    //  for little-endian byte ordering,
    //  or FALSE  for big-endian byte ordering.
    //  Microsoft apps typically use little-endian, while
    //  OpenSSL and other services (such as Amazon CloudFront)
    //  use big-endian.
    CkRsa_putLittleEndian(rsa,FALSE);

    strData = "This is the string to be signed.";

    //  Sign the string using the sha-1 hash algorithm.
    //  Other valid choices are "md2" and "md5".

    hexSig = CkRsa_signStringENC(rsa,strData,"sha-1");

    printf("%s\n",hexSig);

    printf("Success!\n");

    CkCertStore_Dispose(certStore);
    CkRsa_Dispose(rsa);

    }