(MFC) Working with PEM Encrypted Private Keys

Demonstrates how to load and save PEM encrypted private keys.

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

See Also: Using MFC CString in Chilkat

#include <CkGlobal.h>
#include <CkPem.h>
#include <CkFileAccess.h>
#include <CkPrivateKey.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // Starting in v9.5.0.49, all Chilkat classes can be unlocked at once at the beginning of a program
    // by calling UnlockBundle.  It requires a Bundle unlock code.
    CkGlobal chilkatGlob;
    bool success = chilkatGlob.UnlockBundle("Anything for 30-day trial.");
    if (success != true) {
        strOut.append(chilkatGlob.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkPem pem;

    const char *pemPassword = "secret";

    // To load a PEM file containing encrypted private keys, simply
    // provide the password.
    success = pem.LoadPemFile("/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem",pemPassword);
    if (success != true) {
        strOut.append(pem.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkFileAccess fac;
    const char *pemText = fac.readEntireTextFile("/Users/chilkat/testData/pem/pemContainingEncryptedPrivateKeys.pem",pemPassword);

    // To load a PEM from a string, call LoadPem instead of LoadPemFile:
    success = pem.LoadPem(pemText);
    if (success != true) {
        strOut.append(pem.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // A few notes:
    // The PEM may contain both private keys and certificates (or anything else).
    // The password is utilized for whatever content in the PEM is encrypted.  
    // It is OK to have both encrypted and non-encrypted content within a given PEM.

    // PEM private keys can be encrypted in different formats.  The LoadPem and LoadPemFile
    // methods automatically handle the different formats.
    // One format is PKCS8 and is indicated by this delimiter within the PEM:

    // -----BEGIN ENCRYPTED PRIVATE KEY-----
    // MIICoTAbBgkqhkiG9w0BBQMwDgQIfdD0zv24lgkCAggABIICgE0PdHJmRbNs6cBX
    // ...

    // Another format, we'll call "passphrase" looks like this in the PEM:
    // -----BEGIN RSA PRIVATE KEY-----
    // Proc-Type: 4,ENCRYPTED
    // DEK-Info: DES-EDE3-CBC,A4215544D11C5D0C
    // 
    // paqy9XRexcSjurHfG0xhCaUD0HrvIdhuC0CbRxxxeMlkLaV6+uT80rBxt2AaibWG
    // ...

    // Show the bit length of each private key:
    int i;
    int numPrivateKeys = pem.get_NumPrivateKeys();
    if (numPrivateKeys == 0) {
        strOut.append(("Error: Expected the PEM to contain private keys."));
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    for (i = 1; i <= numPrivateKeys; i++) {
        CkPrivateKey *privKey = pem.GetPrivateKey(i - 1);
        strOut.appendInt(i);
        strOut.append(": ");
        strOut.appendInt(privKey->get_BitLength());
        strOut.append(" bits");
        strOut.append("\r\n");
        delete privKey;
    }



    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }