C

Create PKCS1 RSA Signature with PEM Private Key

See more RSA Examples

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

#include <C_CkPrivateKey.h>
#include <C_CkRsa.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPrivateKey pkey;
    HCkRsa rsa;
    const char *strData;
    const char *hexSig;

    success = FALSE;

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

    pkey = CkPrivateKey_Create();

    // Load the private key from an RSA PEM file:
    success = CkPrivateKey_LoadPemFile(pkey,"pvkey2_rsa.pem");
    if (success == FALSE) {
        printf("%s\n",CkPrivateKey_lastErrorText(pkey));
        CkPrivateKey_Dispose(pkey);
        return;
    }

    rsa = CkRsa_Create();

    // Import the private key into the RSA object:
    success = CkRsa_UsePrivateKey(rsa,pkey);
    if (success == FALSE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        CkPrivateKey_Dispose(pkey);
        CkRsa_Dispose(rsa);
        return;
    }

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

    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".
    hexSig = CkRsa_signStringENC(rsa,strData,"sha-1");

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

    printf("Success!\n");


    CkPrivateKey_Dispose(pkey);
    CkRsa_Dispose(rsa);

    }