(C) PKCS7 Sign Text using RSA 2048, SHA256, Base64 Output

Demonstrates how to sign text using 2048-bit RSA with SHA256, producing PKCS#7 output in Base64. The certificate w/ private key used for signing is loaded from a .p12/.pfx file.

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#include <C_CkCert.h>
#include <C_CkCrypt2.h>

void ChilkatSample(void)
    {
    HCkCert cert;
    BOOL success;
    HCkCrypt2 crypt;
    const char *textToSign;
    const char *sigBase64;

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

    cert = CkCert_Create();

    // Load the cert and private key.  Whatever the private key happens to be,
    // such as RSA or ECC, then Chilkat will use it.  If the private key is 
    // a 2048-bit RSA key, then that's what will be used..
    success = CkCert_LoadPfxFile(cert,"qa_data/pfx/myCertAndKey.p12","password");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkCert_Dispose(cert);
        return;
    }

    crypt = CkCrypt2_Create();

    success = CkCrypt2_SetSigningCert(crypt,cert);
    if (success != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCert_Dispose(cert);
        CkCrypt2_Dispose(crypt);
        return;
    }

    // Use SHA-256
    CkCrypt2_putHashAlgorithm(crypt,"sha256");

    // Hash the utf-8 byte representation of the string
    CkCrypt2_putCharset(crypt,"utf-8");

    // Return the result in base64
    CkCrypt2_putEncodingMode(crypt,"base64");

    // Sign some text..
    textToSign = "This is the text to be hashed and signed.";
    sigBase64 = CkCrypt2_opaqueSignStringENC(crypt,textToSign);
    if (CkCrypt2_getLastMethodSuccess(crypt) != TRUE) {
        printf("%s\n",CkCrypt2_lastErrorText(crypt));
        CkCert_Dispose(cert);
        CkCrypt2_Dispose(crypt);
        return;
    }

    printf("%s\n",sigBase64);

    // The result:
    // MIIS2wYJKoZIhvcNAQc ... zGeeY4Oxg==


    CkCert_Dispose(cert);
    CkCrypt2_Dispose(crypt);

    }