Enhance authentication features and dependencies

Updated `DigitalData.Auth.API.csproj` to include new package references for improved security and functionality. Added a `Verify` method in the `Backdoor` class to securely check user credentials against plain text and hashed passwords. Introduced `BackdoorExtensions` with methods for easier retrieval of `Backdoor` instances by username.

src/DigitalData.Auth.API/DigitalData.Auth.API.csproj

@@ -10,6 +10,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="BCrypt.Net-Next" Version="4.0.3" />
     <PackageReference Include="DigitalData.Core.Abstractions" Version="3.4.0" />
     <PackageReference Include="DigitalData.Core.Abstractions.Security" Version="1.0.0" />
     <PackageReference Include="DigitalData.Core.Application" Version="3.2.0" />

src/DigitalData.Auth.API/Models/Backdoor.cs

@@ -7,4 +7,15 @@ public class Backdoor
     public string? Password { get; init; }
 
     public string? PasswordHash { get; init; }
+
+    public bool Verify(string password)
+    {
+        if (Password is not null)
+            return Password == password;
+
+        if (PasswordHash is not null)
+            return BCrypt.Net.BCrypt.Verify(password, PasswordHash);
+
+        return false;
+    }
 }

src/DigitalData.Auth.API/Models/BackdoorExtensions.cs

@@ -0,0 +1,8 @@
+namespace DigitalData.Auth.API.Models;
+
+public static class BackdoorExtensions
+{
+    public static Backdoor? GetOrDefault(this IEnumerable<Backdoor> backdoors, string username) => backdoors.Where(b => b.Username == username).FirstOrDefault();
+
+    public static Backdoor? TryGet(this IEnumerable<Backdoor> backdoors, string username) => backdoors.Where(b => b.Username == username).FirstOrDefault();
+}