CryptoExtensions.cs

namespace Pluton.Core
{
	using System;
	using System.IO;
	using System.Text;
	using System.Linq;
	using System.Collections.Generic;
	using System.Security.Cryptography;

	public static class CryptoExtensions
	{
		static List<string> TrustedHashes;

		public static void Init()
		{
			TrustedHashes = new List<string>();
			string path = DirectoryConfig.GetInstance().GetConfigPath("Hashes");
			if (!File.Exists(path))
				File.AppendAllText(path, "// empty");

			TrustedHashes = (from line in File.ReadAllLines(path)
							 where !String.IsNullOrEmpty(line) && !line.StartsWith("//")
							 select line).ToList();
		}

		public static string GetMD5Hash(MD5 md5Hash, string input)
		{
			return GetMD5Hash(md5Hash, Encoding.UTF8.GetBytes(input));
		}

		public static string GetMD5Hash(MD5 md5Hash, byte[] input)
		{
			byte[] data = md5Hash.ComputeHash(input);

			var sBuilder = new StringBuilder();

			for (int i = 0; i < data.Length; i++)
				sBuilder.Append(data[i].ToString("x2"));

			return sBuilder.ToString();
		}

		public static bool VerifyMD5Hash(this string input)
		{
			using (MD5 md5Hash = MD5.Create()) {
				return TrustedHashes.Contains(GetMD5Hash(md5Hash, input));
			}
		}

		public static bool VerifyMD5Hash(this byte[] input)
		{
			using (MD5 md5Hash = MD5.Create()) {
				return TrustedHashes.Contains(GetMD5Hash(md5Hash, input));
			}
		}

		public static bool VerifyMD5Hash(this string input, string hash)
		{
			using (MD5 md5hash = MD5.Create()) {
				return VerifyMD5Hash(md5hash, input, hash);
			}
		}

		public static bool VerifyMD5Hash(this byte[] input, string hash)
		{
			using (MD5 md5hash = MD5.Create()) {
				return VerifyMD5Hash(md5hash, input, hash);
			}
		}

		public static bool VerifyMD5Hash(MD5 md5Hash, string input, string hash)
		{
			return VerifyMD5Hash(md5Hash, Encoding.UTF8.GetBytes(input), hash);
		}

		public static bool VerifyMD5Hash(MD5 md5Hash, byte[] input, string hash)
		{
			string hashOfInput = GetMD5Hash(md5Hash, input);

			StringComparer comparer = StringComparer.OrdinalIgnoreCase;

			if (0 == comparer.Compare(hashOfInput, hash))
				return true;
			else
				return false;
		}
	}
}