server/util/Hasher.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Cryptography;
+using Microsoft.AspNetCore.Cryptography.KeyDerivation;
+namespace Sockeye.Util
+{
+
+
+    public static class Hasher
+    {
+
+
+        public static string hash(string Salt, string Password)
+        {
+
+            //adapted from here:
+            //https://docs.microsoft.com/en-us/aspnet/core/security/data-protection/consumer-apis/password-hashing
+            string hashed = Convert.ToBase64String(KeyDerivation.Pbkdf2(
+                       password: Password,
+                       salt: Convert.FromBase64String(Salt),
+                       prf: KeyDerivationPrf.HMACSHA512,
+                       iterationCount: 10000,
+                       numBytesRequested: 512 / 8));
+            return hashed;
+        }
+
+        //Generate salt
+        /*
+        Used for many things:
+        DBID, JWT secret key when none provided, User Salt for login / password, 
+        temporary 2fa codes, download tokens, 
+        temporary user pw / login when newly created and haven't been set yet 
+         */
+        public static string GenerateSalt()
+        { 
+            var salt = new byte[32];
+            var random = RandomNumberGenerator.Create();
+            random.GetNonZeroBytes(salt);
+            return Convert.ToBase64String(salt);
+        }
+
+
+
+        public static string GetRandomAlphanumericString(int length)
+        {
+            const string alphanumericCharacters = "0123456789abcdefghijkmnopqrstuvwxyz";
+            return GetRandomString(length, alphanumericCharacters);
+        }
+
+        public static string GetRandomString(int length, IEnumerable<char> characterSet)
+        {
+            if (length < 0)
+                throw new ArgumentException("length must not be negative", "length");
+            if (length > int.MaxValue / 8) 
+                throw new ArgumentException("length is too big", "length");
+            if (characterSet == null)
+                throw new ArgumentNullException("characterSet");
+            var characterArray = characterSet.Distinct().ToArray();
+            if (characterArray.Length == 0)
+                throw new ArgumentException("characterSet must not be empty", "characterSet");
+            var bytes = new byte[length * 8];
+            RandomNumberGenerator.Create().GetBytes(bytes);
+            var result = new char[length];
+            for (int i = 0; i < length; i++)
+            {
+                ulong value = BitConverter.ToUInt64(bytes, i * 8);
+                result[i] = characterArray[value % (uint)characterArray.Length];
+            }
+            return new string(result);
+        }
+
+
+
+    }//eoc
+
+}//eons