Removed NioTSO client and server

- NioTSO client isn't needed because we're using RayLib
- Added FreeSO's API server to handle most backend operations

server/FSO.Server.Common/PasswordHasher.cs

@@ -0,0 +1,103 @@
+using System;
+using System.Linq;
+using System.Security.Cryptography;
+
+namespace FSO.Server.Common
+{
+    public class PasswordHasher
+    {
+        public static PasswordHash Hash(string password)
+        {
+            return Hash(password, "Rfc2898");
+        }
+
+        public static PasswordHash Hash(string password, string scheme)
+        {
+            var schemeImpl = GetScheme(scheme);
+            return schemeImpl.Hash(password);
+        }
+
+        public static bool Verify(string password, PasswordHash hash)
+        {
+            return Verify(password, hash, "Rfc2898");
+        }
+
+        public static bool Verify(string password, PasswordHash hash, string scheme)
+        {
+            var schemeImpl = GetScheme(scheme);
+            return schemeImpl.Verify(password, hash);
+        }
+
+        private static IPasswordHashScheme GetScheme(string scheme)
+        {
+            switch (scheme)
+            {
+                case "Rfc2898":
+                    return new DefaultPasswordHashScheme();
+            }
+
+            throw new Exception("Unknown password hash scheme: " + scheme);
+        }
+    }
+
+    public class PasswordHash
+    {
+        public byte[] data;
+        public string scheme;
+    }
+
+    public class DefaultPasswordHashScheme : IPasswordHashScheme
+    {
+        public PasswordHash Hash(string password)
+        {
+            var salt_input = GetStrongRandomBytes(16);
+            
+
+            return new PasswordHash()
+            {
+                scheme = "Rfc2898",
+                data = Hash(salt_input, password)
+            };
+        }
+
+        private byte[] Hash(byte[] salt_input, string password)
+        {
+            var hasher = new Rfc2898DeriveBytes(System.Text.Encoding.UTF8.GetBytes(password), salt_input, 1000);
+            var hash = hasher.GetBytes(64);
+
+            //Encode the salt + hash together
+            var result = new byte[1 + 16 + hash.Length];
+            result[0] = (byte)16;
+            Array.Copy(salt_input, 0, result, 1, salt_input.Length);
+            Array.Copy(hash, 0, result, salt_input.Length + 1, hash.Length);
+
+            return result;
+        }
+
+        public bool Verify(string password, PasswordHash hash)
+        {
+            var salt_length = hash.data[0];
+            var salt_input = new byte[salt_length];
+            Array.Copy(hash.data, 1, salt_input, 0, salt_length);
+
+            var expected = Hash(salt_input, password);
+            return expected.SequenceEqual(hash.data);
+        }
+
+        private byte[] GetStrongRandomBytes(int numBytes)
+        {
+            var random_bytes = new byte[numBytes];
+            using (RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider())
+            {
+                rngCsp.GetBytes(random_bytes);
+            }
+            return random_bytes;
+        }
+    }
+
+    public interface IPasswordHashScheme
+    {
+        PasswordHash Hash(string password);
+        bool Verify(string password, PasswordHash hash);
+    }
+}