Make auth infer opt in

src/Swashbuckle.AspNetCore.SwaggerGen/DependencyInjection/SwaggerGenOptionsExtensions.cs

@@ -4,6 +4,7 @@
 using Microsoft.OpenApi.Models;
 using Microsoft.AspNetCore.Mvc.ApiExplorer;
 using Swashbuckle.AspNetCore.SwaggerGen;
+using Microsoft.AspNetCore.Authentication;
 
 namespace Microsoft.Extensions.DependencyInjection
 {
@@ -308,6 +309,22 @@ public static void SupportNonNullableReferenceTypes(this SwaggerGenOptions swagg
             swaggerGenOptions.SchemaGeneratorOptions.SupportNonNullableReferenceTypes = true;
         }
 
+        /// <summary>
+        /// Automatically infer security schemes from authentication/authorization state in ASP.NET Core.
+        /// </summary>
+        /// <param name="swaggerGenOptions"></param>
+        /// <param name="securitySchemesSelector">
+        /// Provide alternative implementation that maps ASP.NET Core Authentication schemes to Open API security schemes
+        /// </param>
+        /// <remarks>Currently only supports JWT Bearer authentication</remarks>
+        public static void InferSecuritySchemes(
+            this SwaggerGenOptions swaggerGenOptions,
+            Func<IEnumerable<AuthenticationScheme>, IDictionary<string, OpenApiSecurityScheme>> securitySchemesSelector = null)
+        {
+            swaggerGenOptions.SwaggerGeneratorOptions.InferSecuritySchemes = true;
+            swaggerGenOptions.SwaggerGeneratorOptions.SecuritySchemesSelector = securitySchemesSelector;
+        }
+
         /// <summary>
         /// Extend the Swagger Generator with "filters" that can modify Schemas after they're initially generated
         /// </summary>

src/Swashbuckle.AspNetCore.SwaggerGen/SwaggerGenerator/SwaggerGenerator.cs

@@ -34,26 +34,48 @@ public class SwaggerGenerator : ISwaggerProvider, IAsyncSwaggerProvider
             SwaggerGeneratorOptions options,
             IApiDescriptionGroupCollectionProvider apiDescriptionsProvider,
             ISchemaGenerator schemaGenerator,
-            IAuthenticationSchemeProvider authentiationSchemeProvider) : this(options, apiDescriptionsProvider, schemaGenerator)
+            IAuthenticationSchemeProvider authenticationSchemeProvider) : this(options, apiDescriptionsProvider, schemaGenerator)
         {
-            _authenticationSchemeProvider = authentiationSchemeProvider;
+            _authenticationSchemeProvider = authenticationSchemeProvider;
         }
 
         public async Task<OpenApiDocument> GetSwaggerAsync(string documentName, string host = null, string basePath = null)
         {
-            var (applicableApiDescriptions, swaggerDoc, schemaRepository) = GetSwaggerDocument(documentName, host, basePath);
+            var (applicableApiDescriptions, swaggerDoc, schemaRepository) = GetSwaggerDocumentWithoutFilters(documentName, host, basePath);
+
             swaggerDoc.Components.SecuritySchemes = await GetSecuritySchemes();
+
+            // NOTE: Filter processing moved here so they may effect generated security schemes
+            var filterContext = new DocumentFilterContext(applicableApiDescriptions, _schemaGenerator, schemaRepository);
+            foreach (var filter in _options.DocumentFilters)
+            {
+                filter.Apply(swaggerDoc, filterContext);
+            }
+
+            swaggerDoc.Components.Schemas = new SortedDictionary<string, OpenApiSchema>(swaggerDoc.Components.Schemas, _options.SchemaComparer);
+
             return swaggerDoc;
         }
 
         public OpenApiDocument GetSwagger(string documentName, string host = null, string basePath = null)
         {
-            var (applicableApiDescriptions, swaggerDoc, schemaRepository) = GetSwaggerDocument(documentName, host, basePath);
+            var (applicableApiDescriptions, swaggerDoc, schemaRepository) = GetSwaggerDocumentWithoutFilters(documentName, host, basePath);
+
             swaggerDoc.Components.SecuritySchemes = GetSecuritySchemes().Result;
+
+            // NOTE: Filter processing moved here so they may effect generated security schemes
+            var filterContext = new DocumentFilterContext(applicableApiDescriptions, _schemaGenerator, schemaRepository);
+            foreach (var filter in _options.DocumentFilters)
+            {
+                filter.Apply(swaggerDoc, filterContext);
+            }
+
+            swaggerDoc.Components.Schemas = new SortedDictionary<string, OpenApiSchema>(swaggerDoc.Components.Schemas, _options.SchemaComparer);
+
             return swaggerDoc;
         }
 
-        private (IEnumerable<ApiDescription>, OpenApiDocument, SchemaRepository) GetSwaggerDocument(string documentName, string host = null, string basePath = null)
+        private (IEnumerable<ApiDescription>, OpenApiDocument, SchemaRepository) GetSwaggerDocumentWithoutFilters(string documentName, string host = null, string basePath = null)
         {
             if (!_options.SwaggerDocs.TryGetValue(documentName, out OpenApiInfo info))
                 throw new UnknownSwaggerDocument(documentName, _options.SwaggerDocs.Select(d => d.Key));
@@ -77,38 +99,37 @@ public OpenApiDocument GetSwagger(string documentName, string host = null, strin
                 SecurityRequirements = new List<OpenApiSecurityRequirement>(_options.SecurityRequirements)
             };
 
-            var filterContext = new DocumentFilterContext(applicableApiDescriptions, _schemaGenerator, schemaRepository);
-            foreach (var filter in _options.DocumentFilters)
-            {
-                filter.Apply(swaggerDoc, filterContext);
-            }
-
-            swaggerDoc.Components.Schemas = new SortedDictionary<string, OpenApiSchema>(swaggerDoc.Components.Schemas, _options.SchemaComparer);
-
             return (applicableApiDescriptions, swaggerDoc, schemaRepository);
         }
 
-        private async Task<Dictionary<string, OpenApiSecurityScheme>> GetSecuritySchemes()
+        private async Task<IDictionary<string, OpenApiSecurityScheme>> GetSecuritySchemes()
         {
-            var securitySchemes = new Dictionary<string, OpenApiSecurityScheme>(_options.SecuritySchemes);
-            var authenticationSchemes = Enumerable.Empty<AuthenticationScheme>();
-            if (_authenticationSchemeProvider is not null)
+            if (!_options.InferSecuritySchemes)
             {
-                authenticationSchemes = await _authenticationSchemeProvider.GetAllSchemesAsync();
+                return new Dictionary<string, OpenApiSecurityScheme>(_options.SecuritySchemes);
             }
-            var securitySchemesFromSelector = _options.SecuritySchemesSelector(authenticationSchemes);
-            // Favor security schemes set via options over those generated
-            // from the selector. For the default selector, this effectively
-            // ends up favoring `Bearer` authentication types explicitly set
-            // by the user over those derived by the selector.
-            foreach (var securityScheme in securitySchemesFromSelector)
+
+            var authenticationSchemes = (_authenticationSchemeProvider is not null)
+                ? await _authenticationSchemeProvider.GetAllSchemesAsync()
+                : Enumerable.Empty<AuthenticationScheme>();
+
+            if (_options.SecuritySchemesSelector != null)
             {
-                if (!securitySchemes.ContainsKey(securityScheme.Key))
-                {
-                    securitySchemes.Add(securityScheme.Key, securityScheme.Value);
-                }
+                return _options.SecuritySchemesSelector(authenticationSchemes);
             }
-            return securitySchemes;
+
+            // Default implementation, currently only supports JWT Bearer scheme
+            return authenticationSchemes
+                .Where(authScheme => authScheme.Name == "Bearer")
+                .ToDictionary(
+                    (authScheme) => authScheme.Name,
+                    (authScheme) => new OpenApiSecurityScheme
+                    {
+                        Type = SecuritySchemeType.Http,
+                        Scheme = "bearer", // "bearer" refers to the header name here
+                        In = ParameterLocation.Header,
+                        BearerFormat = "Json Web Token"
+                    });
         }
 
         private IList<OpenApiServer> GenerateServers(string host, string basePath)

src/Swashbuckle.AspNetCore.SwaggerGen/SwaggerGenerator/SwaggerGeneratorOptions.cs

@@ -20,7 +20,7 @@ public SwaggerGeneratorOptions()
             OperationIdSelector = DefaultOperationIdSelector;
             TagsSelector = DefaultTagsSelector;
             SortKeySelector = DefaultSortKeySelector;
-            SecuritySchemesSelector = DefaultSecuritySchemeSelector;
+            SecuritySchemesSelector = null;
             SchemaComparer = StringComparer.Ordinal;
             Servers = new List<OpenApiServer>();
             SecuritySchemes = new Dictionary<string, OpenApiSecurityScheme>();
@@ -45,6 +45,10 @@ public SwaggerGeneratorOptions()
 
         public Func<ApiDescription, string> SortKeySelector { get; set; }
 
+        public bool InferSecuritySchemes { get; set; }
+
+        public Func<IEnumerable<AuthenticationScheme>, IDictionary<string, OpenApiSecurityScheme>> SecuritySchemesSelector { get; set;}
+
         public bool DescribeAllParametersInCamelCase { get; set; }
 
         public List<OpenApiServer> Servers { get; set; }
@@ -63,8 +67,6 @@ public SwaggerGeneratorOptions()
 
         public IList<IDocumentFilter> DocumentFilters { get; set; }
 
-        public Func<IEnumerable<AuthenticationScheme>, Dictionary<string, OpenApiSecurityScheme>> SecuritySchemesSelector { get; set;}
-
         private bool DefaultDocInclusionPredicate(string documentName, ApiDescription apiDescription)
         {
             return apiDescription.GroupName == null || apiDescription.GroupName == documentName;
@@ -106,26 +108,5 @@ private string DefaultSortKeySelector(ApiDescription apiDescription)
         {
             return TagsSelector(apiDescription).First();
         }
-
-        private Dictionary<string, OpenApiSecurityScheme> DefaultSecuritySchemeSelector(IEnumerable<AuthenticationScheme> schemes)
-        {
-            Dictionary<string, OpenApiSecurityScheme> securitySchemes = new();
-#if (NET6_0_OR_GREATER)
-            foreach (var scheme in schemes)
-            {
-                if (scheme.Name == "Bearer")
-                {
-                    securitySchemes[scheme.Name] = new OpenApiSecurityScheme
-                    {
-                        Type = SecuritySchemeType.Http,
-                        Scheme = "bearer", // "bearer" refers to the header name here
-                        In = ParameterLocation.Header,
-                        BearerFormat = "Json Web Token"
-                    };
-                }
-            }
-#endif
-            return securitySchemes;
-        }
     }
 }

test/Swashbuckle.AspNetCore.SwaggerGen.Test/Fixtures/FakeAuthenticationSchemeProvider.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authentication;
+
+namespace Swashbuckle.AspNetCore.SwaggerGen.Test
+{
+    public class FakeAuthenticationSchemeProvider : IAuthenticationSchemeProvider
+    {
+        private readonly IEnumerable<AuthenticationScheme> _authenticationSchemes;
+
+        public FakeAuthenticationSchemeProvider(IEnumerable<AuthenticationScheme> authenticationSchemes)
+        {
+            _authenticationSchemes = authenticationSchemes;
+        }
+
+        public void AddScheme(AuthenticationScheme scheme)
+            => throw new NotImplementedException();
+        public Task<IEnumerable<AuthenticationScheme>> GetAllSchemesAsync()
+            => Task.FromResult(_authenticationSchemes);
+
+        public Task<AuthenticationScheme> GetDefaultAuthenticateSchemeAsync()
+            => Task.FromResult(_authenticationSchemes.First());
+
+        public Task<AuthenticationScheme> GetDefaultChallengeSchemeAsync()
+            => Task.FromResult(_authenticationSchemes.First());
+
+        public Task<AuthenticationScheme> GetDefaultForbidSchemeAsync()
+            => Task.FromResult(_authenticationSchemes.First());
+
+        public Task<AuthenticationScheme> GetDefaultSignInSchemeAsync()
+            => Task.FromResult(_authenticationSchemes.First());
+
+        public Task<AuthenticationScheme> GetDefaultSignOutSchemeAsync()
+            => Task.FromResult(_authenticationSchemes.First());
+
+        public Task<IEnumerable<AuthenticationScheme>> GetRequestHandlerSchemesAsync()
+            => throw new NotImplementedException();
+
+        public Task<AuthenticationScheme> GetSchemeAsync(string name)
+            => Task.FromResult(_authenticationSchemes.First());
+
+        public void RemoveScheme(string name)
+            => throw new NotImplementedException();
+    }
+}