Merge PR #265, Add AES encryption tests

Add ZIP encryption tests for AES128 and AES256

Author: piksel

test/ICSharpCode.SharpZipLib.Tests/Zip/ZipEncryptionHandling.cs

@@ -0,0 +1,144 @@
+using ICSharpCode.SharpZipLib.Zip;
+using NUnit.Framework;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Text;
+
+namespace ICSharpCode.SharpZipLib.Tests.Zip
+{
+	[TestFixture]
+    public class ZipEncryptionHandling
+    {
+		[Test]
+		[Category("Encryption")]
+		[Category("Zip")]
+		public void Aes128Encryption()
+		{
+			CreateZipWithEncryptedEntries("foo", 128);
+		}
+
+		[Test]
+		[Category("Encryption")]
+		[Category("Zip")]
+		public void Aes256Encryption()
+		{
+			CreateZipWithEncryptedEntries("foo", 256);
+		}
+
+		private static readonly string[] possible7zPaths = new[] {
+			// Check in PATH
+			"7z", "7za",
+
+			// Check in default install location
+			Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles), "7-Zip", "7z.exe"),
+			Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86), "7-Zip", "7z.exe"),
+		};
+
+		public static bool TryGet7zBinPath(out string path7z)
+		{
+			var runTimeLimit = TimeSpan.FromSeconds(3);
+
+			foreach (var testPath in possible7zPaths)
+			{
+				try
+				{
+					var p = Process.Start(new ProcessStartInfo(testPath, "i")
+					{
+						RedirectStandardOutput = true
+					});
+					while (!p.StandardOutput.EndOfStream && (DateTime.Now - p.StartTime) < runTimeLimit)
+					{
+						p.StandardOutput.DiscardBufferedData();
+					}
+					if (!p.HasExited)
+					{
+						p.Close();
+						Assert.Warn($"Timed out checking for 7z binary in \"{testPath}\"!");
+						continue;
+					}
+
+					if (p.ExitCode == 0)
+					{
+						path7z = testPath;
+						return true;
+					}
+				}
+				catch (Exception)
+				{
+					continue;
+				}
+			}
+			path7z = null;
+			return false;
+		}
+
+		public void CreateZipWithEncryptedEntries(string password, int keySize)
+		{
+			using (var ms = new MemoryStream())
+			{
+				using (var zs = new ZipOutputStream(ms))
+				{
+					zs.IsStreamOwner = false;
+					zs.SetLevel(9); // 0-9, 9 being the highest level of compression
+					zs.Password = password;  // optional. Null is the same as not setting. Required if using AES.
+
+					ZipEntry zipEntry = new ZipEntry("test");
+					zipEntry.AESKeySize = keySize;
+					zipEntry.DateTime = DateTime.Now;
+
+					zs.PutNextEntry(zipEntry);
+
+					byte[] dummyData = Encoding.UTF8.GetBytes(@"Lorem ipsum dolor sit amet, consectetur adipiscing elit. 
+Fusce bibendum diam ac nunc rutrum ornare. Maecenas blandit elit ligula, eget suscipit lectus rutrum eu. 
+Maecenas aliquam, purus mattis pulvinar pharetra, nunc orci maximus justo, sed facilisis massa dui sed lorem. 
+Vestibulum id iaculis leo. Duis porta ante lorem. Duis condimentum enim nec lorem tristique interdum. Fusce in faucibus libero.");
+
+					using (var dummyStream = new MemoryStream(dummyData))
+					{
+						dummyStream.CopyTo(zs);
+					}
+
+					zs.CloseEntry();
+				}
+
+				if (TryGet7zBinPath(out string path7z))
+				{
+					Console.WriteLine($"Using 7z path: \"{path7z}\"");
+
+					ms.Seek(0, SeekOrigin.Begin);
+
+					var fileName = Path.GetTempFileName();
+
+					try
+					{
+
+						using (var fs = File.OpenWrite(fileName))
+						{
+							ms.CopyTo(fs);
+						}
+
+						var p = Process.Start(path7z, $"t -p{password} {fileName}");
+						if (!p.WaitForExit(2000))
+						{
+							Assert.Warn("Timed out verifying zip file!");
+						}
+
+						Assert.AreEqual(0, p.ExitCode, "Archive verification failed");
+
+					}
+					finally
+					{
+						File.Delete(fileName);
+					}
+				}
+				else
+				{
+					Assert.Warn("Skipping file verification since 7za is not in path");
+				}
+			}
+
+		}
+	}
+}