Create PKCS1 RSA Signature with PEM Private Key

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

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

#include <CkPrivateKey.h>
#include <CkRsa.h>

void ChilkatSample(void)
    {
    CkPrivateKey pkey;

    //  Load the private key from an RSA PEM file:
    pkey.LoadPemFile("pvkey2_rsa.pem");

    bool success;

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

    CkRsa rsa;

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

    success = rsa.UnlockComponent("30-day trial");
    if (success != true) {
        printf("RSA component unlock failed\n");
        return;
    }

    //  Import the private key into the RSA component:
    success = rsa.ImportPrivateKey(pkeyXml);
    if (success != true) {
        printf("%s\n",rsa.lastErrorText());
        return;
    }

    //  This example will sign a string, and receive the signature
    //  in a hex-encoded string.  Therefore, set the encoding mode
    //  to "hex":
    rsa.put_EncodingMode("hex");

    //  If some other non-Chilkat software is going to verify
    //  the signature, it is important to match the byte-ordering.
    //  The LittleEndian property may be set to true
    //  for little-endian byte ordering,
    //  or false  for big-endian byte ordering.
    //  Microsoft apps typically use little-endian, while
    //  OpenSSL and other services (such as Amazon CloudFront)
    //  use big-endian.
    rsa.put_LittleEndian(false);

    const char * strData;
    strData = "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".
    const char * hexSig;
    hexSig = rsa.signStringENC(strData,"sha-1");

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

    printf("Success!\n");
    }