feat/Update_Controllers_to_Allow_for_Premium_Membership

JobTrackerApi/Services/ForwardedProxyConfiguration.cs

@@ -0,0 +1,36 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.HttpOverrides;
+using Microsoft.Extensions.Configuration;
+
+namespace JobTrackerApi.Services;
+
+public static class ForwardedProxyConfiguration
+{
+    public static ForwardedHeadersOptions Build(IConfiguration configuration)
+    {
+        var networks = (configuration.GetSection("Proxy:KnownNetworks").Get<string[]>() ?? Array.Empty<string>())
+            .Select(x => x?.Trim())
+            .Where(x => !string.IsNullOrEmpty(x))
+            .ToArray();
+        if (networks.Length == 0)
+            throw new InvalidOperationException("Proxy:KnownNetworks must contain the nginx proxy CIDR when forwarded headers are enabled.");
+
+        var options = new ForwardedHeadersOptions
+        {
+            ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto,
+            ForwardLimit = 1,
+        };
+        options.KnownNetworks.Clear();
+        options.KnownProxies.Clear();
+
+        foreach (var value in networks)
+        {
+            if (!IPNetwork.TryParse(value, out var network))
+                throw new InvalidOperationException($"Proxy:KnownNetworks contains an invalid CIDR: {value}");
+
+            options.KnownNetworks.Add(network);
+        }
+
+        return options;
+    }
+}