C

Yubikey RSA Encrypt/Decrypt

See more RSA Examples

Demonstrates how to do RSA decryption using a private key stored on a Yubikey (or other USB token or smartcard).

Note: RSA encryption uses the public key, which is freely exportable and does not need to occur on the token/smartcard.

C

#include <C_CkBinData.h>
#include <C_CkCert.h>
#include <C_CkRsa.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkBinData bd;
    HCkCert cert;
    HCkRsa rsa;
    BOOL usePrivateKey;

    success = FALSE;

    // This example assumes you have a certificate with private key on the Yubikey token.
    // When doing simple RSA encryption/decryption, we don't actually need the certificate,
    // but we'll be using the private key associated with the certificate.
    // 
    // The sensitive/secret material that needs to be kept private is the private key.
    // The certificate itself and the public key can be freely shared.
    // 

    // We're going to encrypt and decrypt 32-bytes of data.
    bd = CkBinData_Create();
    success = CkBinData_AppendEncoded(bd,"000102030405060708090A0B0C0D0E0F","hex");
    success = CkBinData_AppendEncoded(bd,"000102030405060708090A0B0C0D0E0F","hex");

    // Let's get the desired cert.
    // For this example, a self-signed certificate with a 2048-bit RSA key was generated in slot 9A.
    cert = CkCert_Create();

    // Force Chilkat to use PKCS11 over ScMinidriver (if on Windows) and Apple Keychain (if on MacOS)
    CkCert_putUncommonOptions(cert,"NoScMinidriver,NoAppleKeychain");

    CkCert_putSmartCardPin(cert,"123456");

    success = CkCert_LoadFromSmartcard(cert,"cn=chilkat_test_2048");
    if (success == FALSE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkBinData_Dispose(bd);
        CkCert_Dispose(cert);
        return;
    }

    // RSA encrypt using the public key.
    rsa = CkRsa_Create();

    // Provide the RSA object with the certificate on the Yubkey.
    success = CkRsa_SetX509Cert(rsa,cert,TRUE);
    if (success == FALSE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        CkBinData_Dispose(bd);
        CkCert_Dispose(cert);
        CkRsa_Dispose(rsa);
        return;
    }

    // RSA encrypt using the public key.
    usePrivateKey = FALSE;
    success = CkRsa_EncryptBd(rsa,bd,usePrivateKey);
    if (success == FALSE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        CkBinData_Dispose(bd);
        CkCert_Dispose(cert);
        CkRsa_Dispose(rsa);
        return;
    }

    printf("RSA Encrypted Output in Hex:\n");
    printf("%s\n",CkBinData_getEncoded(bd,"hex"));

    // Now let's decrypt, using the private key on the Yubikey.
    usePrivateKey = TRUE;
    success = CkRsa_DecryptBd(rsa,bd,usePrivateKey);
    if (success == FALSE) {
        printf("%s\n",CkRsa_lastErrorText(rsa));
        CkBinData_Dispose(bd);
        CkCert_Dispose(cert);
        CkRsa_Dispose(rsa);
        return;
    }

    printf("RSA Decrypted Output in Hex:\n");
    printf("%s\n",CkBinData_getEncoded(bd,"hex"));


    CkBinData_Dispose(bd);
    CkCert_Dispose(cert);
    CkRsa_Dispose(rsa);

    }