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

See more RSA Examples

Note: This example requires Chilkat v11.0.0 or greater.

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

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

    success = FALSE;

    // 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 == FALSE) {
        printf("%s\n",CkCertStore_lastErrorText(certStore));
        CkCertStore_Dispose(certStore);
        return;
    }

    // Find the certificate by the subject common name:
    jsonCN = CkJsonObject_Create();
    CkJsonObject_UpdateString(jsonCN,"CN","cert common name");

    cert = CkCert_Create();
    success = CkCertStore_FindCert(certStore,jsonCN,cert);
    if (success == FALSE) {
        printf("%s\n",CkCertStore_lastErrorText(certStore));
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(jsonCN);
        CkCert_Dispose(cert);
        return;
    }

    privKey = CkPrivateKey_Create();
    success = CkCert_GetPrivateKey(cert,privKey);
    if (success == FALSE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(jsonCN);
        CkCert_Dispose(cert);
        CkPrivateKey_Dispose(privKey);
        return;
    }

    rsa = CkRsa_Create();

    success = CkRsa_UsePrivateKey(rsa,privKey);
    if (success == FALSE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(jsonCN);
        CkCert_Dispose(cert);
        CkPrivateKey_Dispose(privKey);
        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);

    printf("Success!\n");


    CkCertStore_Dispose(certStore);
    CkJsonObject_Dispose(jsonCN);
    CkCert_Dispose(cert);
    CkPrivateKey_Dispose(privKey);
    CkRsa_Dispose(rsa);

    }