From e8d87d8700bfa307a87e80a1025b79d510ff7402 Mon Sep 17 00:00:00 2001
From: Maksym Sadovnychyy <hailstrike@hotmail.com>
Date: Thu, 3 Oct 2024 20:45:37 +0200
Subject: [PATCH] (feature): add otp secret generation

---
 .../Security/TtopGeneratorTests.cs                | 15 ++++++++++++++-
 src/MaksIT.Core/Extensions/StringExtensions.cs    | 10 ++++++++++
 src/MaksIT.Core/MaksIT.Core.csproj                |  2 +-
 src/MaksIT.Core/Security/TtopGenerator.cs         | 11 +++++++++++
 4 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/src/MaksIT.Core.Tests/Security/TtopGeneratorTests.cs b/src/MaksIT.Core.Tests/Security/TtopGeneratorTests.cs
index aaa82f0..984fcb0 100644
--- a/src/MaksIT.Core.Tests/Security/TtopGeneratorTests.cs
+++ b/src/MaksIT.Core.Tests/Security/TtopGeneratorTests.cs
@@ -1,4 +1,5 @@
-using MaksIT.Core.Security;
+using MaksIT.Core.Extensions;
+using MaksIT.Core.Security;
 using System;
 using Xunit;
 
@@ -65,5 +66,17 @@ namespace MaksIT.Core.Tests.Security {
       // Assert
       Assert.True(timestep >= 0);
     }
+
+    [Fact]
+    public void GenerateSecret_ReturnsValidBase32String() {
+      // Act
+      var secret = TotpGenerator.GenerateSecret();
+
+      // Assert
+      Assert.False(string.IsNullOrEmpty(secret));
+      Assert.True(secret.IsBase32String());
+    }
+
+    
   }
 }
diff --git a/src/MaksIT.Core/Extensions/StringExtensions.cs b/src/MaksIT.Core/Extensions/StringExtensions.cs
index 1875015..1c044d1 100644
--- a/src/MaksIT.Core/Extensions/StringExtensions.cs
+++ b/src/MaksIT.Core/Extensions/StringExtensions.cs
@@ -262,5 +262,15 @@ namespace MaksIT.Core.Extensions {
 
       return dt;
     }
+
+    public static bool IsBase32String(this string input) {
+      // Base32 characters are A-Z and 2-7
+      foreach (char c in input) {
+        if (!((c >= 'A' && c <= 'Z') || (c >= '2' && c <= '7'))) {
+          return false;
+        }
+      }
+      return true;
+    }
   }
 }
diff --git a/src/MaksIT.Core/MaksIT.Core.csproj b/src/MaksIT.Core/MaksIT.Core.csproj
index 2768852..bbdc164 100644
--- a/src/MaksIT.Core/MaksIT.Core.csproj
+++ b/src/MaksIT.Core/MaksIT.Core.csproj
@@ -8,7 +8,7 @@
 
     <!-- NuGet package metadata -->
     <PackageId>MaksIT.Core</PackageId>
-    <Version>1.0.6</Version>
+    <Version>1.0.7</Version>
     <Authors>Maksym Sadovnychyy</Authors>
     <Company>MAKS-IT</Company>
     <Product>MaksIT.Core</Product>
diff --git a/src/MaksIT.Core/Security/TtopGenerator.cs b/src/MaksIT.Core/Security/TtopGenerator.cs
index 7a8fea9..a4190d2 100644
--- a/src/MaksIT.Core/Security/TtopGenerator.cs
+++ b/src/MaksIT.Core/Security/TtopGenerator.cs
@@ -59,5 +59,16 @@ public static class TotpGenerator {
     var unixTimestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
     return unixTimestamp / Timestep;
   }
+
+
+  public static string GenerateSecret() {
+    // Example of generating a 32-character base32 secret for TOTP
+    var random = new byte[20];
+    using (var rng = RandomNumberGenerator.Create()) {
+      rng.GetBytes(random);
+    }
+
+    return Base32Encoder.Encode(random); // You can use a Base32 encoder to generate the secret.
+  }
 }