Authenticate

The authenticate function is the foundation of the Truvideo SDK. It securely initiates a session and prepares the SDK for capturing, uploading, and editing media.

This guide will walk you through integrating authentication into your project using the Truvideo Core Module.

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Authentication Integration Guide

Prerequisites

Before you begin:

• Make sure the Core module is integrated. See Installation

• Request your API Key and Secret Key from Truvideo.

Get the API key and Secret Key from Truvideo Support

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Step-by-Step Authentication Flow

Step 1: Prepare Your Credentials

Ensure you have:

• API Key

• Secret Key

• External Id (If provided)

These are needed to sign each authentication request securely.

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Step 2: Generate a Secure Signature

The SDK requires a hashed signature to validate each request. Follow this process to generate one:

1. Build the Payload

   • Use TruvideoSdk.GeneratePayload() to create a dynamic payload string.

2. Sign the Payload

   • Hash the payload using HMAC-SHA256 with your Secret Key.

3. Encode the Signature

   • Convert the hash into a hexadecimal string or base64 format.

4. Send the Signature

   • Include the signature in your authentication request.

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Imports

C#

#if IOS
using UIKit;
using Foundation;
using TruvideoCameraiOS;
#endif

#if ANDROID
using Application = Android.App.Application;
using TruVideoCoreAndroidBinding;
using TruVideoCoreLib = TruVideoCoreAndroid.DotnetCoreTruvideo;
#endif

Async Callback Wrapper

To get callbacks from native wrapper is needed

C#

#if ANDROID
    private Task<T> ExecuteCallbackAsync<T>(Action<CoreCallback> action)
    {
        var tcs = new TaskCompletionSource<T>();

        action.Invoke(new CoreCallback(
            success => MainThread.BeginInvokeOnMainThread(() =>
                tcs.TrySetResult((T)Convert.ChangeType(success, typeof(T)))),
            failure => MainThread.BeginInvokeOnMainThread(() => tcs.TrySetException(new Exception(failure)))
        ));

        return tcs.Task;
    }
#endif

#if IOS
    private Task<T> ExecuteCallbackAsync<T>(Action<Action<string, NSError>> nativeCall) {
        var tcs = new TaskCompletionSource<T>();
        nativeCall((nsResult, error) => {
            if (error != null)
            {
                tcs.SetException(new Exception(error.LocalizedDescription));
            }
            else {
                // Convert NSString to string
                string result = nsResult.ToString();
                tcs.TrySetResult((T)Convert.ChangeType(result, typeof(T)));
               // tcs.SetResult(result);
            }
        });
        return tcs.Task;
    }
#endif

C#

using System.Security.Cryptography;
using System.Text;
namespace TruVideoSampleApp;
public static class HashHelper
{
    public static string? ToSha256String(string signature, string payload)
    {
        try
        {
            var keyBytes = Encoding.UTF8.GetBytes(signature);
            var payloadBytes = Encoding.UTF8.GetBytes(payload);
            using var hmac = new HMACSHA256(keyBytes);
            var hashBytes = hmac.ComputeHash(payloadBytes);
            // Convert to hex string
            var hexString = new StringBuilder();
            foreach (var b in hashBytes) hexString.Append(b.ToString("x2")); // formats byte as lowercase hex
            return hexString.ToString();
        }
        catch (Exception ex)
        {
            // Log or handle exception as needed
            Console.WriteLine(ex);
            return null;
        }
    }
}

1. Test Connection

• Run tests to confirm successful integration.

C#

#if ANDROID
string _init = await ExecuteCallbackAsync<string>(cb => TruVideoCoreLib.InitAppInitializer(Application.Context, cb));
// Step 1: Check if authenticated
bool _isAuthenticate = await ExecuteCallbackAsync<bool>(cb => TruVideoCoreLib.IsAuthenticated(cb));
// Step 2: Check if authentication is expired
bool _isAuthenticationExpired = await ExecuteCallbackAsync<bool>(cb => TruVideoCoreLib.IsAuthenticationExpired(cb));

// Step 3: Generate payload
string _payload = await ExecuteCallbackAsync<string>(cb => TruVideoCoreLib.GeneratePayload(cb));

if (!_isAuthenticate || _isAuthenticationExpired)
{
    // Step 4: Generate SHA-256 signature
    string _signature = HashHelper.ToSha256String(_secretKey, payload);

    // Step 5: Authenticate with API Key, Payload, and Signature
    string authResult = await ExecuteCallbackAsync<string>(cb => TruVideoCoreLib.Authenticate(_apiKey, _payload, _signature, "", cb));
    MainThread.BeginInvokeOnMainThread(() => AuthenticateButtonLabel.Text = $"Result: {authResult}");
}

// Step 6: Initialize Authentication
string _initAuthResult = await ExecuteCallbackAsync<string>(cb => TruVideoCoreLib.InitAuthentication(cb));
MainThread.BeginInvokeOnMainThread(() => AuthenticateButtonLabel.Text = $"Result: {_initAuthResult}");
    
#elif IOS
await Task.Run(async () =>
{
    // Step 1: Check if authenticated
    bool _isAuthenticate = await ExecuteCallbackAsync<bool>(cb => TruvideoCore.Shared.IsAuthenticatedWithCompletionHandler(cb));
    //_isAuthenticate = Convert.ToBoolean(isAuthenticate);

    // Step 2: Check if authentication is expired
    bool _isAuthenticationExpired = await ExecuteCallbackAsync<bool>(cb => TruvideoCore.Shared.IsAuthenticationExpiredWithCompletionHandler(cb));

    // Step 3: Generate payload
    string payload = await ExecuteCallbackAsync<string>(cb => TruvideoCore.Shared.GeneratePayload(cb));

    if (!_isAuthenticate || _isAuthenticationExpired)
    {
        // Step 4: Generate SHA-256 signature
        string signature = HashHelper.ToSha256String(_secretKey, payload);

        // Step 5: Authenticate with API Key, Payload, and Signature
        string authResult = await ExecuteCallbackAsync<string>(cb => TruvideoCore.Shared.AuthenticateWithApiKey(apiKey, payload, "", signature, cb));
    }

    // Step 6: Initialize Authentication
    string initAuthResult = await ExecuteCallbackAsync<string>(cb => TruvideoCore.Shared.InitAuthenticationWithCompletionHandler(cb));
    MainThread.BeginInvokeOnMainThread(() =>
    {
        ActivityIndicator.IsRunning = false;
        AuthenticateButtonLabel.Text = " Authentication Success";
        //CheckAuthentication(); // Refresh UI after authentication
    });
});
#endif

Final Steps: Test Your Integration

After implementing the authentication:

• Run your application to verify that the SDK session initializes successfully.

• Monitor the logs for any issues related to signatures or tokens.

• Once confirmed, proceed to explore media capture, uploading, and editing features.

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Thank you for using the Truvideo SDK. You're now authenticated and ready to explore all features!