feat: Add authorization caching

src/Digdir.Domain.Dialogporten.Application/Common/Extensions/ClaimsPrincipalExtensions.cs

@@ -15,7 +15,10 @@ public static class ClaimsPrincipalExtensions
     private const string IdClaim = "ID";
     private const char IdDelimiter = ':';
     private const string IdPrefix = "0192";
+    private const string AltinnClaimPrefix = "urn:altinn:";
     private const string OrgClaim = "urn:altinn:org";
+    private const string IdportenAuthLevelClaim = "acr";
+    private const string AltinnAuthLevelClaim = "urn:altinn:authlevel";
     private const string PidClaim = "pid";
 
     public static bool TryGetClaimValue(this ClaimsPrincipal claimsPrincipal, string claimType, [NotNullWhen(true)] out string? value)
@@ -86,13 +89,11 @@ public static bool TryGetOrgNumber(this Claim? consumerClaim, [NotNullWhen(true)
 
     public static bool TryGetAuthenticationLevel(this ClaimsPrincipal claimsPrincipal, [NotNullWhen(true)] out int? authenticationLevel)
     {
-        string[] claimTypes = ["acr", "urn:altinn:authlevel"];
-
-        foreach (var claimType in claimTypes)
+        foreach (var claimType in new[] { IdportenAuthLevelClaim, AltinnAuthLevelClaim })
         {
             if (!claimsPrincipal.TryGetClaimValue(claimType, out var claimValue)) continue;
             // The acr claim value is "LevelX" where X is the authentication level
-            var valueToParse = claimType == "acr" ? claimValue[5..] : claimValue;
+            var valueToParse = claimType == IdportenAuthLevelClaim ? claimValue[5..] : claimValue;
             if (!int.TryParse(valueToParse, out var level)) continue;
 
             authenticationLevel = level;
@@ -103,6 +104,16 @@ public static bool TryGetAuthenticationLevel(this ClaimsPrincipal claimsPrincipa
         return false;
     }
 
+    public static IEnumerable<Claim> GetIdentifyingClaims(this List<Claim> claims) =>
+        claims.Where(c =>
+            c.Type == PidClaim ||
+            c.Type == ConsumerClaim ||
+            c.Type == SupplierClaim ||
+            c.Type == OrgClaim ||
+            c.Type == IdportenAuthLevelClaim ||
+            c.Type.StartsWith(AltinnClaimPrefix, StringComparison.Ordinal)
+        ).OrderBy(c => c.Type);
+
     private static bool TryGetOrgShortName(this ClaimsPrincipal claimsPrincipal, [NotNullWhen(true)] out string? orgShortName)
         => claimsPrincipal.FindFirst(OrgClaim).TryGetOrgShortName(out orgShortName);
 

src/Digdir.Domain.Dialogporten.Infrastructure/Altinn/Authorization/AltinnAuthorizationClient.cs

@@ -11,38 +11,47 @@
 using Digdir.Domain.Dialogporten.Domain.Parties.Abstractions;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
+using ZiggyCreatures.Caching.Fusion;
 
 namespace Digdir.Domain.Dialogporten.Infrastructure.Altinn.Authorization;
 
 internal sealed class AltinnAuthorizationClient : IAltinnAuthorization
 {
     private readonly HttpClient _httpClient;
+    private readonly IFusionCache _cache;
     private readonly IUser _user;
     private readonly IDialogDbContext _db;
     private readonly ILogger _logger;
 
     public AltinnAuthorizationClient(
         HttpClient client,
+        IFusionCacheProvider cacheProvider,
         IUser user,
         IDialogDbContext db,
         ILogger<AltinnAuthorizationClient> logger)
     {
         _httpClient = client ?? throw new ArgumentNullException(nameof(client));
+        _cache = cacheProvider.GetCache(nameof(Authorization)) ?? throw new ArgumentNullException(nameof(cacheProvider));
         _user = user ?? throw new ArgumentNullException(nameof(user));
         _db = db ?? throw new ArgumentNullException(nameof(db));
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
     }
 
     public async Task<DialogDetailsAuthorizationResult> GetDialogDetailsAuthorization(DialogEntity dialogEntity,
-        CancellationToken cancellationToken = default) =>
-        await PerformDialogDetailsAuthorization(new DialogDetailsAuthorizationRequest
+        CancellationToken cancellationToken = default)
+    {
+        var request = new DialogDetailsAuthorizationRequest
         {
             Claims = _user.GetPrincipal().Claims.ToList(),
             ServiceResource = dialogEntity.ServiceResource,
             DialogId = dialogEntity.Id,
             Party = dialogEntity.Party,
             AltinnActions = dialogEntity.GetAltinnActions()
-        }, cancellationToken);
+        };
+
+        return await _cache.GetOrSetAsync(request.GenerateCacheKey(), async token
+            => await PerformDialogDetailsAuthorization(request, token), token: cancellationToken);
+    }
 
     public async Task<DialogSearchAuthorizationResult> GetAuthorizedResourcesForSearch(
         List<string> constraintParties,
@@ -51,12 +60,15 @@ public async Task<DialogSearchAuthorizationResult> GetAuthorizedResourcesForSear
         CancellationToken cancellationToken = default)
     {
         var claims = GetOrCreateClaimsBasedOnEndUserId(endUserId);
-        return await PerformNonScalableDialogSearchAuthorization(new DialogSearchAuthorizationRequest
+        var request = new DialogSearchAuthorizationRequest
         {
             Claims = claims,
             ConstraintParties = constraintParties,
             ConstraintServiceResources = serviceResources
-        }, cancellationToken);
+        };
+
+        return await _cache.GetOrSetAsync(request.GenerateCacheKey(), async token
+            => await PerformNonScalableDialogSearchAuthorization(request, token), token: cancellationToken);
     }
 
     private async Task<DialogSearchAuthorizationResult> PerformNonScalableDialogSearchAuthorization(DialogSearchAuthorizationRequest request, CancellationToken cancellationToken)

src/Digdir.Domain.Dialogporten.Infrastructure/Altinn/Authorization/DialogDetailsAuthorizationRequest.cs

@@ -1,4 +1,7 @@
 using System.Security.Claims;
+using System.Security.Cryptography;
+using System.Text;
+using Digdir.Domain.Dialogporten.Application.Common.Extensions;
 using Digdir.Domain.Dialogporten.Application.Externals.AltinnAuthorization;
 
 namespace Digdir.Domain.Dialogporten.Infrastructure.Altinn.Authorization;
@@ -14,3 +17,22 @@ public sealed class DialogDetailsAuthorizationRequest
     // eg. "urn:altinn:subresource:some-sub-resource" or "urn:altinn:task:task_1"
     public required HashSet<AltinnAction> AltinnActions { get; init; }
 }
+
+public static class DialogDetailsAuthorizationRequestExtensions
+{
+    public static string GenerateCacheKey(this DialogDetailsAuthorizationRequest request)
+    {
+        var claimsKey = string.Join(";", request.Claims.GetIdentifyingClaims()
+            .Select(c => $"{c.Type}:{c.Value}"));
+
+        var actionsKey = string.Join(";", request.AltinnActions.OrderBy(a => a.Name)
+            .Select(a => $"{a.Name}:{a.AuthorizationAttribute}"));
+
+        var rawKey = $"{request.DialogId}||{claimsKey}|{actionsKey}";
+
+        var hashBytes = SHA256.HashData(Encoding.UTF8.GetBytes(rawKey));
+        var hashString = BitConverter.ToString(hashBytes).Replace("-", "").ToLowerInvariant();
+
+        return $"auth:details:{hashString}";
+    }
+}

src/Digdir.Domain.Dialogporten.Infrastructure/Altinn/Authorization/DialogSearchAuthorizationRequest.cs

@@ -1,4 +1,7 @@
 using System.Security.Claims;
+using System.Security.Cryptography;
+using System.Text;
+using Digdir.Domain.Dialogporten.Application.Common.Extensions;
 
 namespace Digdir.Domain.Dialogporten.Infrastructure.Altinn.Authorization;
 
@@ -8,3 +11,22 @@ public sealed class DialogSearchAuthorizationRequest
     public List<string> ConstraintParties { get; set; } = [];
     public List<string> ConstraintServiceResources { get; set; } = [];
 }
+
+public static class DialogSearchAuthorizationRequestExtensions
+{
+    public static string GenerateCacheKey(this DialogSearchAuthorizationRequest request)
+    {
+        var claimsKey = string.Join(";", request.Claims.GetIdentifyingClaims()
+            .Select(c => $"{c.Type}:{c.Value}"));
+
+        var partiesKey = string.Join(";", request.ConstraintParties.OrderBy(p => p));
+        var resourcesKey = string.Join(";", request.ConstraintServiceResources.OrderBy(r => r));
+
+        var rawKey = $"{claimsKey}|{partiesKey}|{resourcesKey}";
+
+        var hashBytes = SHA256.HashData(Encoding.UTF8.GetBytes(rawKey));
+        var hashString = BitConverter.ToString(hashBytes).Replace("-", "").ToLowerInvariant();
+
+        return $"auth:search:{hashString}";
+    }
+}

src/Digdir.Domain.Dialogporten.Infrastructure/InfrastructureExtensions.cs

@@ -83,6 +83,29 @@ public static IServiceCollection AddInfrastructure(this IServiceCollection servi
         .ConfigureFusionCache(nameof(Altinn.OrganizationRegistry), new()
         {
             Duration = TimeSpan.FromDays(1)
+        })
+        .ConfigureFusionCache(nameof(Altinn.Authorization), new()
+        {
+            // This cache has high cardinality, and will create several keys per user:
+            // - One entry per user per dialog search and combination of party and service resource parameters
+            // - One entry per dialog details
+            // EU systems iterating over several parties in search view and fetching details for each dialog will
+            // potentially create hundreds over even thousands of cache entries within the cache TTL. To avoid
+            // memory exhaustion, we therefore disable the memory cache for authorization results, and rely solely on
+            // the distributed cache.
+            SkipMemoryCache = true,
+            // In normal operations, 15 minutes delay is deemed acceptable for authorization data
+            Duration = TimeSpan.FromMinutes(15),
+            // In case Altinn Authorization is down/overloaded, we allow the re-usage of stale authorization data
+            // for an additional 15 minutes. Using default FailSafeThrottleDuration.
+            FailSafeMaxDuration = TimeSpan.FromMinutes(30),
+            // If the request to Altinn Authorization takes too long, we allow the cache to return stale data
+            // temporarily whilst updating the cache in the background. Note that we are also using eager refresh
+            // and a backplane.
+            FactorySoftTimeout = TimeSpan.FromSeconds(2),
+            // Timeout for the cache to wait for the factory to complete, which when reached without fail safe data
+            // will cause an exception to be thrown
+            FactoryHardTimeout = TimeSpan.FromSeconds(10),
         });
 
         services.AddDbContext<DialogDbContext>((services, options) =>
@@ -145,7 +168,6 @@ public static IServiceCollection AddInfrastructure(this IServiceCollection servi
                 client.BaseAddress = altinnSettings.BaseUri;
                 client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", altinnSettings.SubscriptionKey);
             })
-            // TODO! Add cache policy based on request body
             .AddPolicyHandlerFromRegistry(PollyPolicy.DefaultHttpRetryPolicy);
 
         if (environment.IsDevelopment())
@@ -173,6 +195,7 @@ public class FusionCacheSettings
         public bool IsFailSafeEnabled { get; set; } = true;
         public TimeSpan JitterMaxDuration { get; set; } = TimeSpan.FromSeconds(2);
         public float EagerRefreshThreshold { get; set; } = 0.8f;
+        public bool SkipMemoryCache { get; set; }
     }
 
     private static IHttpClientBuilder AddMaskinportenHttpClient<TClient, TImplementation, TClientDefinition>(
@@ -216,7 +239,9 @@ private static IServiceCollection ConfigureFusionCache(this IServiceCollection s
                 AllowBackgroundDistributedCacheOperations = settings.AllowBackgroundDistributedCacheOperations,
 
                 JitterMaxDuration = settings.JitterMaxDuration,
-                EagerRefreshThreshold = settings.EagerRefreshThreshold
+                EagerRefreshThreshold = settings.EagerRefreshThreshold,
+
+                SkipMemoryCache = settings.SkipMemoryCache,
             })
             .WithRegisteredSerializer()
             .WithRegisteredDistributedCache()