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Unicode C

PKCS7 Sign Text using RSA 2048, SHA256, Base64 Output

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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.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkCertW.h>
#include <C_CkCrypt2W.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkCertW cert;
    HCkCrypt2W crypt;
    const wchar_t *textToSign;
    const wchar_t *sigBase64;

    success = FALSE;

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

    cert = CkCertW_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 = CkCertW_LoadPfxFile(cert,L"qa_data/pfx/myCertAndKey.p12",L"password");
    if (success != TRUE) {
        wprintf(L"%s\n",CkCertW_lastErrorText(cert));
        CkCertW_Dispose(cert);
        return;
    }

    crypt = CkCrypt2W_Create();

    success = CkCrypt2W_SetSigningCert(crypt,cert);
    if (success != TRUE) {
        wprintf(L"%s\n",CkCrypt2W_lastErrorText(crypt));
        CkCertW_Dispose(cert);
        CkCrypt2W_Dispose(crypt);
        return;
    }

    // Use SHA-256
    CkCrypt2W_putHashAlgorithm(crypt,L"sha256");

    // Hash the utf-8 byte representation of the string
    CkCrypt2W_putCharset(crypt,L"utf-8");

    // Return the result in base64
    CkCrypt2W_putEncodingMode(crypt,L"base64");

    // Sign some text..
    textToSign = L"This is the text to be hashed and signed.";
    sigBase64 = CkCrypt2W_opaqueSignStringENC(crypt,textToSign);
    if (CkCrypt2W_getLastMethodSuccess(crypt) != TRUE) {
        wprintf(L"%s\n",CkCrypt2W_lastErrorText(crypt));
        CkCertW_Dispose(cert);
        CkCrypt2W_Dispose(crypt);
        return;
    }

    wprintf(L"%s\n",sigBase64);

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


    CkCertW_Dispose(cert);
    CkCrypt2W_Dispose(crypt);

    }