(MFC) Rewrite PFX using AES256-SHA256

Demonstrates how to load a .pfx/.p12, examine the encryption algorithm used, and rewrite using aes256-sha256.

Note: This example requires Chilkat v9.5.0.83 or greater.

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

See Also: Using MFC CString in Chilkat

#include <CkPfx.h>
#include <CkJsonObject.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // This example requires Chilkat v9.5.0.83 or greater.

    CkPfx pfx;

    // Let's load a .pfx and examine the encryption algorithms used to protect the private key:
    bool success = pfx.LoadPfxFile("qa_data/pfx/test_secret.pfx","secret");
    if (success == false) {
        strOut.append(pfx.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Examine the algorithms:

    // "pbeWithSHAAnd3_KeyTripleDES_CBC" or "pbes2"?
    strOut.append("Algorithm: ");
    strOut.append(pfx.algorithmId());
    strOut.append("\r\n");

    // If the algorithm is "pbes2" then examine the actual encryption and HMAC algorithms used within pbes2.
    // (If the algorithm is NOT "pbes2", then the following properties are meaningless and will not be modified from their previous values prior to loading the PFX.)
    strOut.append("Pbes2CryptAlg: ");
    strOut.append(pfx.pbes2CryptAlg());
    strOut.append("\r\n");
    strOut.append("Pbes2HmacAlg: ");
    strOut.append(pfx.pbes2HmacAlg());
    strOut.append("\r\n");

    // Our output so far:

    // Algorithm: pbeWithSHAAnd3_KeyTripleDES_CBC
    // Pbes2CryptAlg: aes256-cbc
    // Pbes2HmacAlg: hmacWithSha256

    // This tells us that the PFX we loaded was protected using triple-DES with SHA1.
    // (Most existing .pfx/.p12 files use 3DES w/ SHA1.)
    // The Pbes2CryptAlg and Pbes2HmacAlg properties do not apply here because the AlgorithmId is not equal to "pbes2".  We can ignore those values.

    // Examine the LastJsonData for the call to LoadPfxFile.  This gives us information about what is contained in the PFX, including extended attributes.
    CkJsonObject *json = pfx.LastJsonData();
    json->put_EmitCompact(false);
    strOut.append(json->emit());
    strOut.append("\r\n");

    delete json;

    // Here's a sample LastJsonData:

    // Use this online tool to generate parsing code from sample JSON: 
    // Generate Parsing Code from JSON

    // {
    //   "authenticatedSafe": {
    //     "contentInfo": [
    //       {
    //         "type": "Data",
    //         "safeBag": [
    //           {
    //             "type": "pkcs8ShroudedKeyBag",
    //             "attrs": {
    //               "localKeyId": "16444216",
    //               "keyContainerName": "{F09B755A-1E90-444D-9851-02B86CA14961}",
    //               "msStorageProvider": "Microsoft Enhanced Cryptographic Provider v1.0"
    //             }
    //           }
    //         ]
    //       },
    //       {
    //         "type": "EncryptedData",
    //         "safeBag": [
    //           {
    //             "type": "certBag",
    //             "attrs": {
    //               "localKeyId": "16444216"
    //             },
    //             "subject": "....",
    //             "serialNumber": "9999999999999999999999999999"
    //           },
    //           {
    //             "type": "certBag",
    //             "attrs": {
    //               "authRootSha256Hash": "0vkOXTXKxNQffUTOZq/4heGBX7M5GFhTqH5mwFyb7x4=",
    //               "friendlyName": "XYZ",
    //               "enhKeyUsage": [
    //                 {
    //                   "oid": "1.3.6.1.5.5.7.3.2",
    //                   "usage": "clientAuth"
    //                 },
    //                 {
    //                   "oid": "1.3.6.1.5.5.7.3.4",
    //                   "usage": "emailProtection"
    //                 },
    //                 {
    //                   "oid": "1.3.6.1.5.5.7.3.3",
    //                   "usage": "codeSigning"
    //                 },
    //                 {
    //                   "oid": "1.3.6.1.5.5.7.3.8",
    //                   "usage": "timeStamping"
    //                 },
    //                 {
    //                   "oid": "1.3.6.1.4.1.311.10.3.4",
    //                   "usage": "encryptedFileSystem"
    //                 },
    //                 {
    //                   "oid": "1.3.6.1.5.5.8.2.2",
    //                   "usage": "iKEIntermediate"
    //                 },
    // 
    //                 {
    //                   "oid": "1.3.6.1.5.5.7.3.6",
    //                   "usage": "ipsecTunnel"
    //                 },
    //                 {
    //                   "oid": "1.3.6.1.5.5.7.3.7",
    //                   "usage": "ipsecUser"
    //                 },
    //                 {
    //                   "oid": "1.3.6.1.5.5.7.3.5",
    //                   "usage": "ipsecEndSystem"
    //                 }
    //               ]
    //             },
    //             "subject": "...",
    //             "serialNumber": "8888888888888888888888888888"
    //           },
    //           {
    //             "type": "certBag",
    //             "subject": "...",
    //             "serialNumber": "777777777777777777777777777"
    //           }
    //         ]
    //       }
    //     ]
    //   }
    // }

    // ------------------------------------------------------------------------------------------
    // OK... now let's change the AlgorithmId to "pbes2" 

    pfx.put_AlgorithmId("pbes2");

    // We already know from above that the PBES2 crypt and HMAC algorithms are "aes256-cbc" and "hmacWithSha256".
    // Let's set them anyway just for the example...
    pfx.put_Pbes2CryptAlg("aes256-cbc");
    pfx.put_Pbes2HmacAlg("hmacWithSha256");

    // Rewrite the PFX using pbes2/aes256 + sha256
    success = pfx.ToFile("secret","qa_output/test_secret_aes256.pfx");
    if (success == false) {
        strOut.append(pfx.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    strOut.append("Success.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }