C++

Encrypt with Chilkat, Decrypt with OpenSSL

See more OpenSSL Examples

Demonstrates how to RSA encrypt a string using Chilkat, and then shows the corresponding OpenSSL command to RSA decrypt. The OpenSSL command to decrypt is as follows:

openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

C++

#include <CkRsa.h>
#include <CkPublicKey.h>
#include <CkByteData.h>
#include <CkFileAccess.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkRsa rsa;

    //  Note: RSA encryption uses the public key.  
    //  RSA decryption uses the private key.
    //  The reason is that the public key can be freely provided to anybody.  This allows anybody
    //  to send an encrypted message to the private key owner, and only the private key owner 
    //  can decrypt.
    CkPublicKey key;

    //  Load an RSA public key from a PEM file:
    success = key.LoadFromFile("qa_data/pem/VP_Public.pem");
    if (success == false) {
        std::cout << key.lastErrorText() << "\r\n";
        return;
    }

    //  Load the public key into the RSA object.
    success = rsa.UsePublicKey(key);
    if (success == false) {
        std::cout << rsa.lastErrorText() << "\r\n";
        return;
    }

    const char *strToEncrypt = "00000000;XYZ2-3BHQ-ABCD-MMVV;6MY1-GHJK-9LRR;0";

    //  The LittleEndian property is false by default, but it is set here
    //  anyway to show that LittleEndian byte ordering is required for OpenSSL compatibility.
    rsa.put_LittleEndian(false);

    bool usePrivateKey = false;
    CkByteData encryptedBytes;
    success = rsa.EncryptString(strToEncrypt,usePrivateKey,encryptedBytes);
    if (rsa.get_LastMethodSuccess() == false) {
        std::cout << rsa.lastErrorText() << "\r\n";
        return;
    }

    //  The OpenSSL command to decrypt would be this:
    //  openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

    CkFileAccess fac;
    success = fac.WriteEntireFile("qa_output/rsa_encrypted.bin",encryptedBytes);
    if (success == false) {
        std::cout << fac.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "RSA Encryption Succeeded." << "\r\n";
    }