Dec 14: Reversing #1

using Microsoft.VisualBasic;
using Microsoft.VisualBasic.CompilerServices;
using System;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Runtime.CompilerServices;
using System.Security.Cryptography;
using System.Text;
using System.Windows.Forms;

namespace hv15
{
	[DesignerGenerated]
	public class Form1 : Form
	{
		public class GlobalVariables
		{
			public static string assembly = "__ERROR_HANDLER";
		}

		private IContainer components;

		[AccessedThroughProperty("Button1")]
		private Button _Button1;

		[AccessedThroughProperty("TextBox1")]
		private TextBox _TextBox1;

		[AccessedThroughProperty("Label1")]
		private Label _Label1;

		[AccessedThroughProperty("PictureBox1")]
		private PictureBox _PictureBox1;

		[AccessedThroughProperty("Label2")]
		private Label _Label2;

		internal virtual Button Button1
		{
			get
			{
				return this._Button1;
			}
			[MethodImpl(MethodImplOptions.Synchronized)]
			set
			{
				EventHandler value2 = new EventHandler(this.Button1_Click);
				if (this._Button1 != null)
				{
					this._Button1.Click -= value2;
				}
				this._Button1 = value;
				if (this._Button1 != null)
				{
					this._Button1.Click += value2;
				}
			}
		}

		internal virtual TextBox TextBox1
		{
			get
			{
				return this._TextBox1;
			}
			[MethodImpl(MethodImplOptions.Synchronized)]
			set
			{
				this._TextBox1 = value;
			}
		}

		internal virtual Label Label1
		{
			get
			{
				return this._Label1;
			}
			[MethodImpl(MethodImplOptions.Synchronized)]
			set
			{
				this._Label1 = value;
			}
		}

		internal virtual PictureBox PictureBox1
		{
			get
			{
				return this._PictureBox1;
			}
			[MethodImpl(MethodImplOptions.Synchronized)]
			set
			{
				this._PictureBox1 = value;
			}
		}

		internal virtual Label Label2
		{
			get
			{
				return this._Label2;
			}
			[MethodImpl(MethodImplOptions.Synchronized)]
			set
			{
				this._Label2 = value;
			}
		}

		public Form1()
		{
			base.Load += new EventHandler(this.Form1_Load);
			this.InitializeComponent();
		}

		[DebuggerNonUserCode]
		protected override void Dispose(bool disposing)
		{
			try
			{
				if (disposing && this.components != null)
				{
					this.components.Dispose();
				}
			}
			finally
			{
				base.Dispose(disposing);
			}
		}

		[DebuggerStepThrough]
		private void InitializeComponent()
		{
			ComponentResourceManager componentResourceManager = new ComponentResourceManager(typeof(Form1));
			this.Button1 = new Button();
			this.TextBox1 = new TextBox();
			this.Label1 = new Label();
			this.PictureBox1 = new PictureBox();
			this.Label2 = new Label();
			((ISupportInitialize)this.PictureBox1).BeginInit();
			this.SuspendLayout();
			Control arg_70_0 = this.Button1;
			Point location = new Point(266, 143);
			arg_70_0.Location = location;
			this.Button1.Name = "Button1";
			Control arg_98_0 = this.Button1;
			Size size = new Size(87, 25);
			arg_98_0.Size = size;
			this.Button1.TabIndex = 0;
			this.Button1.Text = "Verify";
			this.Button1.UseVisualStyleBackColor = true;
			Control arg_DA_0 = this.TextBox1;
			location = new Point(266, 108);
			arg_DA_0.Location = location;
			this.TextBox1.Name = "TextBox1";
			Control arg_105_0 = this.TextBox1;
			size = new Size(333, 20);
			arg_105_0.Size = size;
			this.TextBox1.TabIndex = 1;
			this.Label1.AutoSize = true;
			Control arg_137_0 = this.Label1;
			location = new Point(263, 79);
			arg_137_0.Location = location;
			this.Label1.Name = "Label1";
			Control arg_162_0 = this.Label1;
			size = new Size(336, 14);
			arg_162_0.Size = size;
			this.Label1.TabIndex = 2;
			this.Label1.Text = "Please enter the daily Code and click on Verify";
			this.PictureBox1.Image = (Image)componentResourceManager.GetObject("PictureBox1.Image");
			Control arg_1B0_0 = this.PictureBox1;
			location = new Point(12, 12);
			arg_1B0_0.Location = location;
			this.PictureBox1.Name = "PictureBox1";
			Control arg_1DE_0 = this.PictureBox1;
			size = new Size(233, 156);
			arg_1DE_0.Size = size;
			this.PictureBox1.TabIndex = 3;
			this.PictureBox1.TabStop = false;
			this.Label2.AutoSize = true;
			this.Label2.Enabled = false;
			Control arg_22B_0 = this.Label2;
			location = new Point(438, 154);
			arg_22B_0.Location = location;
			this.Label2.Name = "Label2";
			Control arg_256_0 = this.Label2;
			size = new Size(161, 14);
			arg_256_0.Size = size;
			this.Label2.TabIndex = 4;
			this.Label2.Text = "code by HACKVent santa";
			SizeF autoScaleDimensions = new SizeF(7f, 14f);
			this.AutoScaleDimensions = autoScaleDimensions;
			this.AutoScaleMode = AutoScaleMode.Font;
			size = new Size(617, 180);
			this.ClientSize = size;
			this.Controls.Add(this.Label2);
			this.Controls.Add(this.PictureBox1);
			this.Controls.Add(this.Label1);
			this.Controls.Add(this.TextBox1);
			this.Controls.Add(this.Button1);
			this.Font = new Font("Courier New", 8.25f, FontStyle.Regular, GraphicsUnit.Point, 0);
			this.FormBorderStyle = FormBorderStyle.FixedToolWindow;
			this.Name = "Form1";
			this.StartPosition = FormStartPosition.CenterScreen;
			this.Text = "HACKVent 2015";
			((ISupportInitialize)this.PictureBox1).EndInit();
			this.ResumeLayout(false);
			this.PerformLayout();
		}

		private void Button1_Click(object sender, EventArgs e)
		{
			string text = this.TextBox1.Text;
			string left = this.Encrypt(text, Form1.GlobalVariables.assembly);
			if (Operators.CompareString(left, "zV5/UFU8PUD3N2T49IBuCwvGzCLYz39tkMZts7rfBU4=", false) == 0)
			{
				Interaction.MsgBox("yes, that is the key!", MsgBoxStyle.Information, "HACKVent 2015");
			}
			else
			{
				Interaction.MsgBox("nope, that is NOT the key!", MsgBoxStyle.Critical, "HACKVent 2015");
			}
		}

		public string Encrypt(string input, string pass)
		{
			RijndaelManaged rijndaelManaged = new RijndaelManaged();
			MD5CryptoServiceProvider mD5CryptoServiceProvider = new MD5CryptoServiceProvider();
			string result;
			try
			{
				byte[] array = new byte[32];
				byte[] sourceArray = mD5CryptoServiceProvider.ComputeHash(Encoding.ASCII.GetBytes(pass));
				Array.Copy(sourceArray, 0, array, 0, 16);
				Array.Copy(sourceArray, 0, array, 15, 16);
				rijndaelManaged.Key = array;
				rijndaelManaged.Mode = CipherMode.ECB;
				ICryptoTransform cryptoTransform = rijndaelManaged.CreateEncryptor();
				byte[] bytes = Encoding.ASCII.GetBytes(input);
				result = Convert.ToBase64String(cryptoTransform.TransformFinalBlock(bytes, 0, bytes.Length));
			}
			catch (Exception expr_7B)
			{
				ProjectData.SetProjectError(expr_7B);
				Exception ex = expr_7B;
				Interaction.MsgBox(ex.Message, MsgBoxStyle.OkOnly, null);
				result = "";
				ProjectData.ClearProjectError();
			}
			return result;
		}

		private void Form1_Load(object sender, EventArgs e)
		{
			this.Show();
			this.TextBox1.Focus();
		}
	}
}

using System;
using System.Security.Cryptography;
using System.Text;

public class Program
{
	public static void Main()
	{

		string pass = "__ERROR_HANDLER";
		string target= "zV5/UFU8PUD3N2T49IBuCwvGzCLYz39tkMZts7rfBU4=";
		byte[] keyarray = new byte[32];

		// Base64 decrypt target string
		byte[] target2 = Convert.FromBase64String(target);

		// Set our encryption/decryption key
		MD5CryptoServiceProvider mD5CryptoServiceProvider = new MD5CryptoServiceProvider();
		byte[] sourceArray = mD5CryptoServiceProvider.ComputeHash(Encoding.ASCII.GetBytes(pass));
		Array.Copy(sourceArray, 0, keyarray, 0, 16);
		Array.Copy(sourceArray, 0, keyarray, 15, 16);

		// Set up Rijndael Decrypt
		RijndaelManaged rijndaelManaged = new RijndaelManaged();
		rijndaelManaged.Key = keyarray;
		rijndaelManaged.Mode = CipherMode.ECB;
		ICryptoTransform cryptoTransformDecrypt = rijndaelManaged.CreateDecryptor();

		// Do it
		byte[] result = cryptoTransformDecrypt.TransformFinalBlock(target2,0, target2.Length);
		System.Text.Encoding encoding = new System.Text.ASCIIEncoding();

		// print result
		Console.WriteLine(encoding.GetString(result));
	}
}