Harden NTLM authentication and restore SGU profiles

tests/SGU.AuthBroker.Tests/NtlmCredentialValidatorTests.cs

@@ -0,0 +1,167 @@
+using System.Net;
+using System.Net.Http.Headers;
+using Microsoft.Extensions.Logging.Abstractions;
+using SGU.AuthBroker.Core.Authentication;
+using SGU.AuthBroker.Core.Identity;
+using SGU.AuthBroker.Options;
+using SGU.AuthBroker.Services;
+using Xunit;
+
+namespace SGU.AuthBroker.Tests;
+
+public sealed class NtlmCredentialValidatorTests
+{
+    private static readonly UserIdentity Student = new(
+        "AL123456",
+        "AL",
+        "123456",
+        InstitutionalRole.Student);
+
+    [Fact]
+    public async Task RedirectAndSuccessWithoutChallengeNeverAuthorizes()
+    {
+        SequenceHandler handler = new(
+            Redirect("/psulsa/login.aspx?AspxAutoDetectCookieSupport=1"),
+            Response(HttpStatusCode.OK));
+        NtlmCredentialValidator validator = CreateValidator(handler);
+
+        NtlmValidationResult result = await validator.ValidateAsync(
+            Student,
+            "test-password",
+            TestContext.Current.CancellationToken);
+
+        Assert.Equal(NtlmValidationStatus.Unavailable, result.Status);
+        Assert.Equal("NTLM_CHALLENGE_MISSING", result.ErrorCode);
+        Assert.Equal(2, handler.RequestPaths.Count);
+    }
+
+    [Fact]
+    public async Task CredentialsAreAcceptedOnlyAfterExplicitNtlmChallenge()
+    {
+        SequenceHandler handler = new(
+            Challenge(),
+            Response(HttpStatusCode.OK),
+            Response(HttpStatusCode.OK));
+        NtlmCredentialValidator validator = CreateValidator(handler);
+
+        NtlmValidationResult result = await validator.ValidateAsync(
+            Student,
+            "test-password",
+            TestContext.Current.CancellationToken);
+
+        Assert.Equal(NtlmValidationStatus.Valid, result.Status);
+        Assert.Equal(3, handler.RequestPaths.Count);
+        Assert.Equal("/psulsa/", handler.RequestPaths[0]);
+        Assert.Equal("/psulsa/", handler.RequestPaths[1]);
+        Assert.Equal(
+            "/psulsa/alumnos/consultainformacionalumnos/consultainformacion.aspx",
+            handler.RequestPaths[2]);
+    }
+
+    [Fact]
+    public async Task RejectedCredentialsAfterChallengeAreInvalid()
+    {
+        SequenceHandler handler = new(
+            Challenge(),
+            Challenge());
+        NtlmCredentialValidator validator = CreateValidator(handler);
+
+        NtlmValidationResult result = await validator.ValidateAsync(
+            Student,
+            "wrong-password",
+            TestContext.Current.CancellationToken);
+
+        Assert.Equal(NtlmValidationStatus.Invalid, result.Status);
+        Assert.Equal("INVALID_INSTITUTIONAL_CREDENTIALS", result.ErrorCode);
+        Assert.Equal(2, handler.RequestPaths.Count);
+    }
+
+    [Fact]
+    public async Task SessionBootstrapRetriesOriginalRoleProfile()
+    {
+        SequenceHandler handler = new(
+            Challenge(),
+            Redirect("/psulsa/login.aspx?AspxAutoDetectCookieSupport=1"),
+            Redirect("/psulsa/menu.aspx"),
+            Response(HttpStatusCode.OK),
+            Response(HttpStatusCode.OK));
+        NtlmCredentialValidator validator = CreateValidator(handler);
+
+        NtlmValidationResult result = await validator.ValidateAsync(
+            Student,
+            "test-password",
+            TestContext.Current.CancellationToken);
+
+        Assert.Equal(NtlmValidationStatus.Valid, result.Status);
+        Assert.Equal(5, handler.RequestPaths.Count);
+        Assert.Equal("/psulsa/login.aspx", handler.RequestPaths[2]);
+        Assert.Equal("/psulsa/menu.aspx", handler.RequestPaths[3]);
+        Assert.Equal(
+            "/psulsa/alumnos/consultainformacionalumnos/consultainformacion.aspx",
+            handler.RequestPaths[4]);
+    }
+
+    private static NtlmCredentialValidator CreateValidator(SequenceHandler handler)
+    {
+        BrokerOptions options = new()
+        {
+            Ntlm = new NtlmOptions
+            {
+                Endpoint = "https://sgu.example/",
+                AuthenticationPath = "/psulsa/",
+                StudentProfilePath = "/psulsa/alumnos/consultainformacionalumnos/consultainformacion.aspx",
+                AllowedRedirectHosts = ["sgu.example"],
+                TimeoutSeconds = 5,
+                ProfileTimeoutSeconds = 5
+            }
+        };
+        return new NtlmCredentialValidator(
+            options,
+            NullLogger<NtlmCredentialValidator>.Instance,
+            (_, _) => handler);
+    }
+
+    private static HttpResponseMessage Challenge()
+    {
+        HttpResponseMessage response = Response(HttpStatusCode.Unauthorized);
+        response.Headers.WwwAuthenticate.Add(new AuthenticationHeaderValue("Negotiate"));
+        response.Headers.WwwAuthenticate.Add(new AuthenticationHeaderValue("NTLM"));
+        return response;
+    }
+
+    private static HttpResponseMessage Redirect(string location)
+    {
+        HttpResponseMessage response = Response(HttpStatusCode.Found);
+        response.Headers.Location = new Uri(location, UriKind.Relative);
+        return response;
+    }
+
+    private static HttpResponseMessage Response(HttpStatusCode statusCode) =>
+        new(statusCode)
+        {
+            Content = new StringContent("<html></html>")
+        };
+
+    private sealed class SequenceHandler(params HttpResponseMessage[] responses) : HttpMessageHandler
+    {
+        private readonly Queue<HttpResponseMessage> responses = new(responses);
+
+        public List<string> RequestPaths { get; } = [];
+
+        protected override Task<HttpResponseMessage> SendAsync(
+            HttpRequestMessage request,
+            CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            RequestPaths.Add(request.RequestUri!.AbsolutePath);
+            if (responses.Count == 0)
+            {
+                throw new InvalidOperationException("The validator sent more requests than expected.");
+            }
+
+            HttpResponseMessage response = responses.Dequeue();
+            response.RequestMessage = request;
+            return Task.FromResult(response);
+        }
+    }
+}