Improving custom JWT authentication

schemas/dab.draft.schema.json

@@ -457,6 +457,18 @@
                     "issuer": {
                       "type": "string",
                       "description": "The expected issuer (iss) claim of incoming JWT tokens."
+                    },
+                    "rolesPath": {
+                      "type": "string",
+                      "description": "The JWT claim name that should be treated as the role claim for authorization checks. Defaults to 'roles'."
+                    },
+                    "rolesSeparator": {
+                      "type": "string",
+                      "description": "Optional separator used when the configured role claim is emitted as a single string containing multiple roles or permissions. If omitted, the role claim is treated as a single scalar value unless it is a JSON array."
+                    },
+                    "jwksUri": {
+                      "type": "string",
+                      "description": "Optional JWKS endpoint URI. If omitted, DAB derives it from the issuer as '{issuer}/.well-known/jwks.json'."
                     }
                   },
                   "required": [ "audience", "issuer" ]

src/Config/ObjectModel/DataSource.cs

@@ -83,6 +83,12 @@ public int DatasourceThresholdMs
                 SetSessionContext: ReadBoolOption(namingPolicy.ConvertName(nameof(MsSqlOptions.SetSessionContext))));
         }
 
+        if (typeof(TOptionType).IsAssignableFrom(typeof(PostgreSqlOptions)))
+        {
+            return (TOptionType)(object)new PostgreSqlOptions(
+                SetSessionContext: ReadBoolOption(namingPolicy.ConvertName(nameof(PostgreSqlOptions.SetSessionContext))));
+        }
+
         throw new NotSupportedException($"The type {typeof(TOptionType).FullName} is not a supported strongly typed options object");
     }
 
@@ -126,6 +132,11 @@ public record CosmosDbNoSQLDataSourceOptions(string? Database, string? Container
 /// </summary>
 public record MsSqlOptions(bool SetSessionContext = true) : IDataSourceOptions;
 
+/// <summary>
+/// Options for PostgreSql database.
+/// </summary>
+public record PostgreSqlOptions(bool SetSessionContext = true) : IDataSourceOptions;
+
 /// <summary>
 /// Options for user-delegated authentication (OBO) for a data source.
 /// 

src/Config/ObjectModel/JwtOptions.cs

@@ -1,6 +1,36 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+using System.Text.Json.Serialization;
+
 namespace Azure.DataApiBuilder.Config.ObjectModel;
 
-public record JwtOptions(string? Audience, string? Issuer);
+public record JwtOptions
+{
+    [JsonPropertyName("audience")]
+    public string? Audience { get; init; }
+
+    [JsonPropertyName("issuer")]
+    public string? Issuer { get; init; }
+
+    [JsonPropertyName("rolesPath")]
+    public string? RolesPath { get; init; }
+
+    [JsonPropertyName("rolesSeparator")]
+    public string? RolesSeparator { get; init; }
+
+    [JsonPropertyName("jwksUrl")]
+    public string? JwksUrl { get; init; }
+
+    public string ResolvedRoleClaimType => string.IsNullOrWhiteSpace(RolesPath)
+        ? AuthenticationOptions.ROLE_CLAIM_TYPE
+        : RolesPath;
+
+    public string? ResolvedRolesSeparator => string.IsNullOrEmpty(RolesSeparator)
+        ? null
+        : RolesSeparator;
+
+    public string? ResolvedJwksUrl => string.IsNullOrWhiteSpace(JwksUrl)
+        ? (string.IsNullOrWhiteSpace(Issuer) ? null : $"{Issuer.TrimEnd('/')}/.well-known/jwks.json")
+        : JwksUrl;
+}

src/Core/AuthenticationHelpers/ClientRoleHeaderAuthenticationMiddleware.cs

@@ -89,7 +89,7 @@ public async Task InvokeAsync(HttpContext httpContext)
         // Manually set the httpContext.User to the Principal from the AuthenticateResult
         // when we exclude setting a default authentication scheme in Startup.cs AddAuthentication().
         // https://learn.microsoft.com/aspnet/core/security/authorization/limitingidentitybyscheme
-        if (authNResult.Succeeded)
+        if (authNResult.Succeeded && authNResult.Principal is not null)
         {
             httpContext.User = authNResult.Principal;
         }
@@ -198,7 +198,8 @@ private static string ResolveConfiguredAuthNScheme(string? configuredProviderNam
             return UnauthenticatedAuthenticationDefaults.AUTHENTICATIONSCHEME;
         }
         else if (string.Equals(configuredProviderName, SupportedAuthNProviders.AZURE_AD, StringComparison.OrdinalIgnoreCase) ||
-            string.Equals(configuredProviderName, SupportedAuthNProviders.ENTRA_ID, StringComparison.OrdinalIgnoreCase))
+            string.Equals(configuredProviderName, SupportedAuthNProviders.ENTRA_ID, StringComparison.OrdinalIgnoreCase) ||
+            string.Equals(configuredProviderName, SupportedAuthNProviders.GENERIC_OAUTH, StringComparison.OrdinalIgnoreCase))
         {
             return JwtBearerDefaults.AuthenticationScheme;
         }

src/Core/AuthenticationHelpers/ConfigureJwtBearerOptions.cs

@@ -5,7 +5,9 @@
 using Azure.DataApiBuilder.Core.Configurations;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
 using Microsoft.Extensions.Options;
+using Microsoft.IdentityModel.Tokens;
 using Microsoft.IdentityModel.Validators;
+using Azure.DataApiBuilder.Core.AuthenticationHelpers;
 
 namespace Azure.DataApiBuilder.Service;
 
@@ -49,14 +51,46 @@ public void Configure(string? name, JwtBearerOptions options)
         options.MapInboundClaims = false;
         options.Audience = newAuthOptions.Jwt.Audience;
         options.Authority = newAuthOptions.Jwt.Issuer;
+
+        string? jwksUri = newAuthOptions.Jwt.ResolvedJwksUrl;
+        if (string.IsNullOrWhiteSpace(jwksUri))
+        {
+            return;
+        }
+
+        JsonWebKeySet jwks;
+
+        using (HttpClient client = JwtHttpClientFactory.Create())
+        {
+            string jwksJson = client.GetStringAsync(jwksUri).GetAwaiter().GetResult();
+            jwks = new JsonWebKeySet(jwksJson);
+        }
+
         options.TokenValidationParameters = new Microsoft.IdentityModel.Tokens.TokenValidationParameters()
         {
             ValidAudience = newAuthOptions.Jwt.Audience,
             ValidIssuer = newAuthOptions.Jwt.Issuer,
-            // Instructs the asp.net core middleware to use the data in the "roles" claim for User.IsInRole()
-            // See https://learn.microsoft.com/en-us/dotnet/api/system.security.claims.claimsprincipal.isinrole#remarks
-            // This should eventually be configurable to address #2395
-            RoleClaimType = AuthenticationOptions.ROLE_CLAIM_TYPE
+            ValidateIssuer = true,
+            ValidateAudience = true,
+            ValidateLifetime = true,
+            ValidateIssuerSigningKey = true,
+            IssuerSigningKeys = jwks.Keys,
+            // Instructs the asp.net core middleware which JWT claim to use for User.IsInRole()
+            // Defaults to "roles" when not explicitly configured.
+            RoleClaimType = newAuthOptions.Jwt.ResolvedRoleClaimType
+        };
+
+        options.Events = new JwtBearerEvents
+        {
+            OnTokenValidated = context =>
+            {
+                JwtRoleClaimsTransformer.NormalizeRoleClaims(
+                    principal: context.Principal!,
+                    sourceRoleClaimType: newAuthOptions.Jwt.ResolvedRoleClaimType,
+                    separator: newAuthOptions.Jwt.ResolvedRolesSeparator);
+
+                return Task.CompletedTask;
+            }
         };
 
         if (newAuthOptions.Provider.Equals("AzureAD") || newAuthOptions.Provider.Equals("EntraID"))

src/Core/AuthenticationHelpers/JwtHttpClientFactory.cs

@@ -0,0 +1,23 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+namespace Azure.DataApiBuilder.Service;
+
+public static class JwtHttpClientFactory
+{
+    public static HttpClient Create()
+    {
+        bool allowSelfSigned = Environment.GetEnvironmentVariable("USE_SELF_SIGNED_CERT")
+            ?.Equals("true", StringComparison.OrdinalIgnoreCase) == true;
+
+        HttpClientHandler handler = new();
+
+        if (allowSelfSigned)
+        {
+            handler.ServerCertificateCustomValidationCallback =
+                HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;
+        }
+
+        return new HttpClient(handler, disposeHandler: true);
+    }
+}

src/Core/AuthenticationHelpers/JwtRoleClaimsTransformer.cs

@@ -0,0 +1,127 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.Security.Claims;
+using System.Text.Json;
+
+namespace Azure.DataApiBuilder.Core.AuthenticationHelpers;
+
+public static class JwtRoleClaimsTransformer
+{
+    public static void NormalizeRoleClaims(
+        ClaimsPrincipal principal,
+        string sourceRoleClaimType,
+        string? separator)
+    {
+        foreach (ClaimsIdentity identity in principal.Identities)
+        {
+            if (!identity.IsAuthenticated)
+            {
+                continue;
+            }
+
+            List<Claim> sourceClaims = identity.Claims
+                .Where(c => c.Type.Equals(sourceRoleClaimType, StringComparison.Ordinal))
+                .ToList();
+
+            if (sourceClaims.Count == 0)
+            {
+                continue;
+            }
+
+            HashSet<string> normalizedValues = new(StringComparer.OrdinalIgnoreCase);
+
+            foreach (Claim claim in sourceClaims)
+            {
+                foreach (string expandedValue in ExpandClaimValues(claim.Value, separator))
+                {
+                    if (!string.IsNullOrWhiteSpace(expandedValue))
+                    {
+                        normalizedValues.Add(expandedValue.Trim());
+                    }
+                }
+            }
+
+            foreach (string normalizedValue in normalizedValues)
+            {
+                bool exactClaimAlreadyExists = identity.Claims.Any(c =>
+                    c.Type.Equals(sourceRoleClaimType, StringComparison.Ordinal) &&
+                    c.Value.Equals(normalizedValue, StringComparison.OrdinalIgnoreCase));
+
+                if (!exactClaimAlreadyExists)
+                {
+                    identity.AddClaim(new Claim(sourceRoleClaimType, normalizedValue, ClaimValueTypes.String));
+                }
+            }
+        }
+    }
+
+    private static IEnumerable<string> ExpandClaimValues(string rawValue, string? separator)
+    {
+        if (string.IsNullOrWhiteSpace(rawValue))
+        {
+            yield break;
+        }
+
+        string trimmed = rawValue.Trim();
+
+        // 1. JSON array support
+        if (trimmed.StartsWith('[') && trimmed.EndsWith(']'))
+        {
+            List<string>? values;
+            try
+            {
+                values = JsonSerializer.Deserialize<List<string>>(trimmed);
+            }
+            catch (JsonException)
+            {
+                values = null;
+            }
+
+            if (values is not null)
+            {
+                foreach (string value in values)
+                {
+                    if (!string.IsNullOrWhiteSpace(value))
+                    {
+                        yield return value.Trim();
+                    }
+                }
+
+                yield break;
+            }
+        }
+
+        // 2. Configurable separated string support
+        if (!string.IsNullOrEmpty(separator))
+        {
+            string[] splitValues;
+
+            if (separator.Length == 1)
+            {
+                splitValues = trimmed.Split(
+                    separator[0],
+                    StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+            }
+            else
+            {
+                splitValues = trimmed.Split(
+                    new[] { separator },
+                    StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+            }
+
+            foreach (string value in splitValues)
+            {
+                if (!string.IsNullOrWhiteSpace(value))
+                {
+                    yield return value;
+                }
+            }
+
+            yield break;
+        }
+
+        // 3. Single scalar fallback
+        yield return trimmed;
+    }
+}

src/Core/Authorization/AuthorizationResolver.cs

@@ -718,12 +718,16 @@ public static Dictionary<string, List<Claim>> GetAllAuthenticatedUserClaims(Http
                 continue;
             }
 
+            string resolvedRoleClaimType = string.IsNullOrWhiteSpace(identity.RoleClaimType)
+                ? AuthenticationOptions.ROLE_CLAIM_TYPE
+                : identity.RoleClaimType;
+
             // DAB will only resolve one 'roles' claim whose value matches the x-ms-api-role header value
             // because DAB executes requests in the context of a single role. The `roles` claim
             // resolved here can be forwarded to MSSQL's set-session-context. Modifying this behavior
             // is a breaking change.
             if (!resolvedClaims.ContainsKey(AuthenticationOptions.ROLE_CLAIM_TYPE) &&
-                identity.HasClaim(type: AuthenticationOptions.ROLE_CLAIM_TYPE, value: clientRoleHeader))
+                identity.HasClaim(type: resolvedRoleClaimType, value: clientRoleHeader))
             {
                 List<Claim> roleClaim = new()
                 {
@@ -737,8 +741,9 @@ public static Dictionary<string, List<Claim>> GetAllAuthenticatedUserClaims(Http
             // into a list and storing that in resolvedClaims using the claimType as the key.
             foreach (Claim claim in identity.Claims)
             {
-                // 'roles' claim has already been processed. But we preserve the original 'roles' claim.
-                if (claim.Type.Equals(AuthenticationOptions.ROLE_CLAIM_TYPE))
+                // The source JWT role claim has already been processed.
+                // Preserve the original source claim under original_roles.
+                if (claim.Type.Equals(resolvedRoleClaimType))
                 {
                     if (!resolvedClaims.TryAdd(AuthenticationOptions.ORIGINAL_ROLE_CLAIM_TYPE, new List<Claim>() { claim }))
                     {

src/Core/Resolvers/OboSqlTokenProvider.cs

@@ -222,9 +222,15 @@ private static string ComputeAuthorizationContextHash(ClaimsPrincipal principal)
     {
         List<string> values = [];
 
+        HashSet<string> roleClaimTypes = principal.Identities
+            .Select(identity => string.IsNullOrWhiteSpace(identity.RoleClaimType)
+                ? AuthenticationOptions.ROLE_CLAIM_TYPE
+                : identity.RoleClaimType)
+            .ToHashSet(StringComparer.OrdinalIgnoreCase);
+
         foreach (Claim claim in principal.Claims)
         {
-            if (claim.Type.Equals(AuthenticationOptions.ROLE_CLAIM_TYPE, StringComparison.OrdinalIgnoreCase) ||
+            if (roleClaimTypes.Contains(claim.Type) ||
                 claim.Type.Equals("scp", StringComparison.OrdinalIgnoreCase))
             {
                 string[] parts = claim.Value.Split(