(C) RSA Sign with PKCS8 Encrypted Key

See more RSA Examples

Note: This example requires Chilkat v11.0.0 or greater.

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#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_LoadPkcs8EncryptedFile(pkey,"privateKey.key","myPassword");

    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;
    }

    // Return the signature in 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", "sha256", "sha384", "sha512",  and "md5".
    hexSig = CkRsa_signStringENC(rsa,strData,"sha-1");

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


    CkPrivateKey_Dispose(pkey);
    CkRsa_Dispose(rsa);

    }