(Unicode C) Create PKCS1 RSA Signature with PEM Private Key

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Demonstrates how to load a private key from a PEM file and create a PKCS1 RSA digital signature.

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#include <C_CkPrivateKeyW.h>
#include <C_CkRsaW.h>

void ChilkatSample(void)
    {
    HCkPrivateKeyW pkey;
    BOOL success;
    const wchar_t *pkeyXml;
    HCkRsaW rsa;
    const wchar_t *strData;
    const wchar_t *hexSig;

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

    pkey = CkPrivateKeyW_Create();

    // Load the private key from an RSA PEM file:
    success = CkPrivateKeyW_LoadPemFile(pkey,L"pvkey2_rsa.pem");

    // Get the private key in XML format:
    pkeyXml = CkPrivateKeyW_getXml(pkey);

    rsa = CkRsaW_Create();

    // Import the private key into the RSA object:
    success = CkRsaW_ImportPrivateKey(rsa,pkeyXml);
    if (success != TRUE) {
        wprintf(L"%s\n",CkRsaW_lastErrorText(rsa));
        CkPrivateKeyW_Dispose(pkey);
        CkRsaW_Dispose(rsa);
        return;
    }

    // Get the signature as hex.
    CkRsaW_putEncodingMode(rsa,L"hex");

    strData = L"This is the string to be signed.";

    // Sign the string using the sha-1 hash algorithm.
    // Other valid choices are "md2", "md5", "sha256",
    // "sha384", and "sha512".
    hexSig = CkRsaW_signStringENC(rsa,strData,L"sha-1");

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

    wprintf(L"Success!\n");


    CkPrivateKeyW_Dispose(pkey);
    CkRsaW_Dispose(rsa);

    }