File SDK republishing quickstart (C++)

Overview

For an overview of this scenario and where you might use it, see Republishing in the MIP SDK.

Prerequisites

If you haven't already, be sure to complete the following prerequisites before continuing:

  • Quickstart: Set and get sensitivity labels (C++). Complete this quickstart first. It builds a starter Visual Studio solution that lists an organization's sensitivity labels and sets and reads sensitivity labels on a file. This "How to - Downgrade/Remove a label that needs a justification C++" quickstart builds on the previous one.
  • Optionally: Review File handlers in the MIP SDK concepts.
  • Optionally: Review Protection handlers in the MIP SDK concepts.

Add logic to the FileHandler observer class

To decrypt a protected file, call the GetDecryptedTemporaryFileAsync() method exposed by mip::FileHandler. Define success and failure callbacks for the async method as shown in the following example.

  1. Open the Visual Studio solution you created in the previous "Quickstart: Set and get sensitivity labels (C++)" article.

  2. In Solution Explorer, open the filehandler_observer.h file in your project. Toward the end of the FileHandler definition, before };, add the following lines for the method declarations.

        void OnGetDecryptedTemporaryFileSuccess(const std::string& decryptedFilePath, const std::shared_ptr<void>& context) override;
    void OnGetDecryptedTemporaryFileFailure(const std::exception_ptr& error, const std::shared_ptr<void>& context) override;

  3. In Solution Explorer, open the filehandler_observer.cpp file in your project. Toward the end of the file, add the following lines for the method definitions.

    
    void FileHandlerObserver::OnGetDecryptedTemporaryFileSuccess(const std::string& decryptedFilePath, const std::shared_ptr<void>& context) {
    auto promise = std::static_pointer_cast<std::promise<std::string>>(context);
    promise->set_value(decryptedFilePath);
    }

    void FileHandlerObserver::OnGetDecryptedTemporaryFileFailure(const std::exception_ptr& error, const std::shared_ptr<void>& context) {
    auto promise = std::static_pointer_cast<std::promise<std::string>>(context);
    promise->set_exception(error);
    }

Add logic to edit and republish a protected file

  1. In Solution Explorer, open the .cpp file in your project that contains the implementation of the main() method. It defaults to the same name as the project containing it, which you specified during project creation.

  2. Toward the end of the main() body, after system("pause"); and before return 0; where you left off in the previous quickstart, insert the following code:

//Originally protected file's path.
std::string protectedFilePath = "<protected-file-path>";

// Create file handler for the file
auto handlerPromise = std::make_shared<std::promise<std::shared_ptr<FileHandler>>>();
auto handlerFuture = handlerPromise->get_future();
engine->CreateFileHandlerAsync(protectedFilePath, 
                                protectedFilePath, 
                                true, 
                                std::make_shared<FileHandlerObserver>(), 
                                handlerPromise);
auto protectedFileHandler = handlerFuture.get();

// retieve and store protection handler from file
auto protectionHandler = protectedFileHandler->GetProtection();

//Check if the user has the 'Edit' right to the file and if so decrypt the file.
if (protectionHandler->AccessCheck("Edit")) {

    // Decrypt file to temp path using the same file handler
    auto tempPromise = std::make_shared<std::promise<string>>();
    auto tempFuture = tempPromise->get_future();
    protectedFileHandler->GetDecryptedTemporaryFileAsync(tempPromise);
    auto tempPath = tempFuture.get();

    /// Write code here to perform further operations for edit ///

    /// Follow steps below for re-protecting the edited file ///

    // Create a new file handler using the temporary file path.
    auto reprotectPromise = std::make_shared<std::promise<std::shared_ptr<FileHandler>>>();
    auto reprotectFuture = reprotectPromise->get_future();
    engine->CreateFileHandlerAsync(tempPath, 
                                    tempPath, 
                                    true, 
                                    std::make_shared<FileHandlerObserver>(), 
                                    reprotectPromise);
    auto republishHandler = reprotectFuture.get();

    // Set protection using the ProtectionHandler from the original consumption operation.
    republishHandler->SetProtection(protectionHandler);
    std::string reprotectedFilePath = "<protected-file-path>";

    // Commit changes
    auto republishPromise = std::make_shared<std::promise<bool>>();
    auto republishFuture = republishPromise->get_future();
    republishHandler->CommitAsync(reprotectedFilePath, republishPromise);

    // Validate republishing
    cout << "Protected File: " + protectedFilePath<<endl;
    cout << "Protected Label ID: " + protectedFileHandler->GetLabel()->GetLabel()->GetId() << endl;
    cout << "Protection Owner: " + protectedFileHandler->GetProtection()->GetOwner() << endl<<endl;

    cout << "Republished File: " + reprotectedFilePath<<endl;
    cout << "Republished Label ID: " + republishHandler->GetLabel()->GetLabel()->GetId() << endl;
    cout << "Republished Owner: " + republishHandler->GetProtection()->GetOwner() << endl;
}

  1. Toward the end of main(), find the application shutdown block created in the previous quickstart and add the following handler lines to release resources.

        protectedFileHandler = nullptr;
    protectionHandler = nullptr;

  2. Replace the placeholder values in the source code using the following values:

    Placeholder Value
    <protected-file-path> The protected file from the previous quickstart.
    <reprotected-file-path> The output file path for the modified file to republish.

Build and test the application

Build and test your client application.

  1. Use CTRL-SHIFT-B (Build Solution) to build your client application. If the build has no errors, use F5 (Start debugging) to run your application.

  2. If your project builds and runs successfully, the application prompts for an access token each time the SDK calls your AcquireOAuth2Token() method. As you did previously in the "Set and get sensitivity label" quickstart, run your PowerShell script to acquire the token each time with the values provided for $authority and $resourceUrl.

  Sensitivity labels for your organization:
  Non-Business : 87ba5c36-17cf-14793-bbc2-bd5b3a9f95cz
  Public : 83867195-f2b8-2ac2-b0b6-6bb73cb33afz
  General : f42a3342-8706-4288-bd31-ebb85995028z
  Confidential : 074e457c-5848-4542-9a6f-34a182080e7z
  Highly Confidential : f55c2dea-db0f-47cd-8520-a52e1590fb6z
  Press any key to continue . . .

  Applying Label ID 074e457c-5848-4542-9a6f-34a182080e7z to C:\Test\Test.docx
  Committing changes
  
  Label committed to file: C:\Test\Test_labeled.docx
  Press any key to continue . . .

  Run the PowerShell script to generate an access token using the following values, then copy/paste it below:
  Set $authority to: https://login.microsoftonline.com/37f4583d-9985-4e7f-a1ab-71afd8b55ba0
  Set $resourceUrl to: https://aadrm.com
  Sign in with user account: user1@tenant.onmicrosoft.com
  Enter access token: <paste-access-token-here>
  Press any key to continue . . .

  Getting the label committed to file: C:\Test\Test_labeled.docx
  Name: Confidential
  Id: 074e457c-5848-4542-9a6f-34a182080e7z
  Press any key to continue . . .
  Protected File: C:\Test\Test_labeled.docx
  Protected Label ID: 074e457c-5848-4542-9a6f-34a182080e7z
  Protection Owner: user1@tenant.onmicrosoft.com

  Republished File: c:\Test\Test_republished.docx
  Republished Label ID: 074e457c-5848-4542-9a6f-34a182080e7z
  Republished Owner: user1@tenant.onmicrosoft.com

  Press any key to close this window . . .

Next steps

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