(C) RSA Signature with Certificate's Private Key from PFX

See more RSA Examples

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

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

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

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

    // 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));
        CkCertStore_Dispose(certStore);
        return;
    }

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

    pkey = CkCert_ExportPrivateKey(cert);
    if (CkCert_getLastMethodSuccess(cert) == FALSE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCert_Dispose(cert);
        CkCertStore_Dispose(certStore);
        return;
    }

    CkCert_Dispose(cert);

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

    rsa = CkRsa_Create();

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

    // Encode the signature as a hex string
    CkRsa_putEncodingMode(rsa,"hex");

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

    // Sign the string using the sha-1 hash algorithm.
    // Other valid choices are "sha-256", "md2" and "md5".
    hexSig = CkRsa_signStringENC(rsa,strData,"sha-1");

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

    CkPrivateKey_Dispose(pkey);

    printf("Success!\n");


    CkCertStore_Dispose(certStore);
    CkRsa_Dispose(rsa);

    }