Verify Java Signature

Demonstrates how to verify a digital signature produced by Java.
The Java code that produces a digital signature that can be verified with
this Chilkat example is found at: http://www.cknotes.com/?p=283

Downloads:

MS Windows Visual C/C++ Libraries

Linux/CentOS C/C++ Libraries

MAC OS X C/C++ Libraries

Solaris C/C++ Libraries

C++ Builder Libraries

// Needs #include <CkPublicKey.h>
// Needs #include <CkRsa.h>

    CkString strOut;


    CkPublicKey pubKey;

    bool success;

    //  Load an RSA public key from an ASN.1 DER file
    success = pubKey.LoadRsaDerFile("pubKey.der");

    if (success != true) {
        strOut.append(pubKey.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    const char * pkeyXml;
    //  Get the public key in XML format:
    pkeyXml = pubKey.getXml();

    CkRsa rsa;

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

    success = rsa.UnlockComponent("30-day trial");
    if (success != true) {
        strOut.append(rsa.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    //  Import the public key into the RSA component:
    success = rsa.ImportPublicKey(pkeyXml);
    if (success != true) {
        strOut.append(rsa.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    rsa.put_EncodingMode("base64");

    const char * strData;
    strData = "The quick brown fox jumps over the lazy dog";

    //  IMPORTANT:  This Base64 signature will have to be updated
    //  with the digital signature produced by the Java code at:
    //  http://www.cknotes.com/?p=283
    const char * base64Sig;
    base64Sig = "VGV5A+bodHBpBwwJZdf17Bv+lkBTm/gteOf8iCgEEfNzBosZLaAB8X55BIZIkE2zKRXoMcJT+iCxsj+1hnlwJeKZ+Gya58lrHw6NWm2N0O/KyfnuEzADOM86X0xrkgdFT6SYpbZ9dWPC59NiHeEdVyjOXNJ3fBpUSQ5/5pvVWm0=";

    //  Verify the signature produced by the Java code at:
    //  http://www.cknotes.com/?p=283
    //  The VerifyStringENC method hashes the input data and verifies
    //  the hash against the signature.
    success = rsa.VerifyStringENC(strData,"sha-1",base64Sig);
    //  Is the signature verified?
    if (success == true) {
        strOut.append("Signature Verified!");
        strOut.append("\r\n");
    }
    else {
        strOut.append("Signature not verified!");
        strOut.append("\r\n");
    }



    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());