(MFC) RSA Decrypt using PEM

This example demonstrates decryping RSA encrypted data that is base64 encoded. It uses a private key loaded from a PEM file.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

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

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkRsa rsa;

    CkPrivateKey key;

    // Load an RSA private key from an unencrypted PEM file:
    // (To load from an encrypted PEM file, call LoadEncryptedPemFile instead.)

    bool success = key.LoadPemFile("qa_data/rsa/decryptTest/priv.pem");
    if (success != true) {
        strOut.append(key.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Make the key available to the RSA object
    success = rsa.ImportPrivateKeyObj(key);
    if (success != true) {
        strOut.append(rsa.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    const char *encryptedStr = "pP9XFJEsGgxPNHEgNiLB5H5ksCOXDk/G49BPTog1jKLAhYofV4UTH5k2TOYiqRnDnKs8+8uPoN/IxdiGXvuYG8HRzN0HtkhoZO/AxeyaB9S7eddCUlT0Pl2PEB2yQ9HG5rM7jqYOD6MAM4cuX7hqT8fa8tbzJzmBwdfFDBz94bwQjULHiO+gklIBC4vhkXT4yjuvEjxTAKU6tJeZYkBooJNdS/vE5RZRpuF6bGZU41Qc17qFR+iReBq+9f8IMmw8WR8fMbOCaygOfFS1nw7JVsIMGsAIXS8rUaJ/2DfGPfQx5HCiVtTOreGYRUI3esAQjnvUCnavZyQgs53nl7e2aA==";

    rsa.put_EncodingMode("base64");

    bool usePrivateKey = true;
    const char *decryptedStr = rsa.decryptStringENC(encryptedStr,usePrivateKey);

    strOut.append("Decrypted:");
    strOut.append("\r\n");
    strOut.append(decryptedStr);
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }