C Requires Chilkat v10.1.2+

RSA Sign using Private Key of Certificate Type A3 (smart card / token)

Demonstrates RSA signing data using the private key of a certificate type A3 (smart card, token).

Note: This is a Windows-only example.

C

#include <C_CkCertStore.h>
#include <C_CkJsonObject.h>
#include <C_CkCert.h>
#include <C_CkRsa.h>
#include <C_CkByteData.h>
#include <C_CkFileAccess.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCertStore certStore;
    const char *thumbprint;
    BOOL bReadOnly;
    HCkJsonObject json;
    HCkCert cert;
    HCkRsa rsa;
    BOOL bUsePrivateKey;
    HCkByteData dataToSign;
    HCkByteData sigData;
    HCkFileAccess fac;

    success = FALSE;

    //  First get the A3 certificate that was installed on the Windows system.
    certStore = CkCertStore_Create();

    thumbprint = "12c1dd8015f3f03f7b1fa619dc24e2493ca8b4b2";

    //  This is specific to Windows because it is opening the Windows Current-User certificate store.
    bReadOnly = TRUE;
    success = CkCertStore_OpenCurrentUserStore(certStore,bReadOnly);
    if (success != TRUE) {
        printf("%s\n",CkCertStore_lastErrorText(certStore));
        CkCertStore_Dispose(certStore);
        return;
    }

    //  Find the certificate with the desired thumbprint
    //  (There are many ways to locate a certificate.  This example chooses to find by thumbprint.)
    json = CkJsonObject_Create();
    CkJsonObject_UpdateString(json,"thumbprint",thumbprint);

    cert = CkCert_Create();
    success = CkCertStore_FindCert(certStore,json,cert);
    if (success == FALSE) {
        printf("Failed to find the certificate.\n");
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(json);
        CkCert_Dispose(cert);
        return;
    }

    printf("Found: %s\n",CkCert_subjectCN(cert));

    rsa = CkRsa_Create();

    //  Provide the cert's private key
    bUsePrivateKey = TRUE;
    success = CkRsa_SetX509Cert(rsa,cert,bUsePrivateKey);
    if (success != TRUE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(json);
        CkCert_Dispose(cert);
        CkRsa_Dispose(rsa);
        return;
    }

    //  Now we're ready to sign..
    dataToSign = CkByteData_Create();
    sigData = CkByteData_Create();

    //  Get bytes to be signed..
    fac = CkFileAccess_Create();
    success = CkFileAccess_ReadEntireFile(fac,"in.dat",dataToSign);

    success = CkRsa_SignBytes(rsa,dataToSign,"SHA-256",sigData);
    if (success != TRUE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        CkCertStore_Dispose(certStore);
        CkJsonObject_Dispose(json);
        CkCert_Dispose(cert);
        CkRsa_Dispose(rsa);
        CkByteData_Dispose(dataToSign);
        CkByteData_Dispose(sigData);
        CkFileAccess_Dispose(fac);
        return;
    }

    printf("Signature created.\n");


    CkCertStore_Dispose(certStore);
    CkJsonObject_Dispose(json);
    CkCert_Dispose(cert);
    CkRsa_Dispose(rsa);
    CkByteData_Dispose(dataToSign);
    CkByteData_Dispose(sigData);
    CkFileAccess_Dispose(fac);

    }