api/adapter.go

@@ -4,3 +4,10 @@ import "net/http"
 
 // Adapter to encapsulate incoming requests
 type Adapter func(http.HandlerFunc) http.HandlerFunc
+
+// AuthHandlerFunc is http.HandlerFunc with additional Authorization information
+type AuthHandlerFunc func(Auth, http.ResponseWriter, *http.Request)
+
+// AuthAdapter to encapsulate incoming request with access to api.Auth
+// to manage permissions
+type AuthAdapter func(AuthHandlerFunc) AuthHandlerFunc

api/auth.go

@@ -0,0 +1,62 @@
+package api
+
+// Auth can be used by http middleware to
+// 1) consult required roles in @Auth.Required
+// 2) update active roles in @Auth.Active
+type Auth struct {
+	// required roles for this request
+	// - the first dimension of the array reads as a OR
+	// - the second dimension reads as a AND
+	//
+	// Example:
+	// [ [A, B], [C, D] ] reads: roles (A and B) or (C and D) are required
+	//
+	// Warning: must not be mutated
+	Required [][]string
+
+	// active roles to be updated by authentication
+	// procedures (e.g. jwt)
+	Active []string
+}
+
+// Granted returns whether the authorization is granted
+// i.e. Auth.Active fulfills Auth.Required
+func (a Auth) Granted() bool {
+	var nothingRequired = true
+
+	// first dimension: OR ; at least one is valid
+	for _, required := range a.Required {
+		// empty list
+		if len(required) < 1 {
+			continue
+		}
+
+		nothingRequired = false
+
+		// second dimension: AND ; all required must be fulfilled
+		if a.fulfills(required) {
+			return true
+		}
+	}
+
+	return nothingRequired
+}
+
+// returns whether Auth.Active fulfills (contains) all @required roles
+func (a Auth) fulfills(required []string) bool {
+	for _, requiredRole := range required {
+		var found = false
+		for _, activeRole := range a.Active {
+			if activeRole == requiredRole {
+				found = true
+				break
+			}
+		}
+		// missing role -> fail
+		if !found {
+			return false
+		}
+	}
+	// all @required are fulfilled
+	return true
+}

api/auth_test.go

@@ -0,0 +1,108 @@
+package api
+
+import (
+	"testing"
+)
+
+func TestCombination(t *testing.T) {
+	tcases := []struct {
+		Name     string
+		Required [][]string
+		Active   []string
+		Granted  bool
+	}{
+		{
+			Name:     "no requirement none given",
+			Required: [][]string{},
+			Active:   []string{},
+			Granted:  true,
+		},
+		{
+			Name:     "no requirement 1 given",
+			Required: [][]string{},
+			Active:   []string{"a"},
+			Granted:  true,
+		},
+		{
+			Name:     "no requirement some given",
+			Required: [][]string{},
+			Active:   []string{"a", "b"},
+			Granted:  true,
+		},
+
+		{
+			Name:     "1 required none given",
+			Required: [][]string{{"a"}},
+			Active:   []string{},
+			Granted:  false,
+		},
+		{
+			Name:     "1 required fulfilled",
+			Required: [][]string{{"a"}},
+			Active:   []string{"a"},
+			Granted:  true,
+		},
+		{
+			Name:     "1 required mismatch",
+			Required: [][]string{{"a"}},
+			Active:   []string{"b"},
+			Granted:  false,
+		},
+		{
+			Name:     "2 required none gien",
+			Required: [][]string{{"a", "b"}},
+			Active:   []string{},
+			Granted:  false,
+		},
+		{
+			Name:     "2 required other given",
+			Required: [][]string{{"a", "b"}},
+			Active:   []string{"c"},
+			Granted:  false,
+		},
+		{
+			Name:     "2 required one given",
+			Required: [][]string{{"a", "b"}},
+			Active:   []string{"a"},
+			Granted:  false,
+		},
+		{
+			Name:     "2 required fulfilled",
+			Required: [][]string{{"a", "b"}},
+			Active:   []string{"a", "b"},
+			Granted:  true,
+		},
+		{
+			Name:     "2 or 2 required first fulfilled",
+			Required: [][]string{{"a", "b"}, {"c", "d"}},
+			Active:   []string{"a", "b"},
+			Granted:  true,
+		},
+		{
+			Name:     "2 or 2 required second fulfilled",
+			Required: [][]string{{"a", "b"}, {"c", "d"}},
+			Active:   []string{"c", "d"},
+			Granted:  true,
+		},
+	}
+
+	for _, tcase := range tcases {
+		t.Run(tcase.Name, func(t *testing.T) {
+
+			auth := Auth{
+				Required: tcase.Required,
+				Active:   tcase.Active,
+			}
+
+			// all right
+			if tcase.Granted == auth.Granted() {
+				return
+			}
+
+			if tcase.Granted && !auth.Granted() {
+				t.Fatalf("expected granted authorization")
+			}
+			t.Fatalf("unexpected granted authorization")
+		})
+	}
+}

builder.go

@@ -13,9 +13,10 @@ import (
 
 // Builder for an aicra server
 type Builder struct {
-	conf     *config.Server
+	conf         *config.Server
-	handlers []*apiHandler
+	handlers     []*apiHandler
-	adapters []api.Adapter
+	adapters     []api.Adapter
+	authAdapters []api.AuthAdapter
 }
 
 // represents an api handler (method-pattern combination)
@@ -40,8 +41,8 @@ func (b *Builder) AddType(t datatype.T) error {
 	return nil
 }
 
-// Use adds an http adapter (middleware)
+// With adds an http adapter (middleware)
-func (b *Builder) Use(adapter api.Adapter) {
+func (b *Builder) With(adapter api.Adapter) {
 	if b.conf == nil {
 		b.conf = &config.Server{}
 	}
@@ -51,6 +52,17 @@ func (b *Builder) Use(adapter api.Adapter) {
 	b.adapters = append(b.adapters, adapter)
 }
 
+// WithAuth adds an http adapter with auth capabilities (middleware)
+func (b *Builder) WithAuth(adapter api.AuthAdapter) {
+	if b.conf == nil {
+		b.conf = &config.Server{}
+	}
+	if b.authAdapters == nil {
+		b.authAdapters = make([]api.AuthAdapter, 0)
+	}
+	b.authAdapters = append(b.authAdapters, adapter)
+}
+
 // Setup the builder with its api definition file
 // panics if already setup
 func (b *Builder) Setup(r io.Reader) error {

builder_test.go

@@ -1,12 +1,8 @@
 package aicra
 
 import (
-	"bytes"
-	"context"
 	"errors"
-	"fmt"
 	"net/http"
-	"net/http/httptest"
 	"strings"
 	"testing"
 
@@ -52,92 +48,6 @@ func TestAddType(t *testing.T) {
 	}
 }
 
-func TestUse(t *testing.T) {
-	builder := &Builder{}
-	if err := addBuiltinTypes(builder); err != nil {
-		t.Fatalf("unexpected error <%v>", err)
-	}
-
-	// build @n middlewares that take data from context and increment it
-	n := 1024
-
-	type ckey int
-	const key ckey = 0
-
-	middleware := func(next http.HandlerFunc) http.HandlerFunc {
-		return func(w http.ResponseWriter, r *http.Request) {
-			newr := r
-
-			// first time -> store 1
-			value := r.Context().Value(key)
-			if value == nil {
-				newr = r.WithContext(context.WithValue(r.Context(), key, int(1)))
-				next(w, newr)
-				return
-			}
-
-			// get value and increment
-			cast, ok := value.(int)
-			if !ok {
-				t.Fatalf("value is not an int")
-			}
-			cast++
-			newr = r.WithContext(context.WithValue(r.Context(), key, cast))
-			next(w, newr)
-		}
-	}
-
-	// add middleware @n times
-	for i := 0; i < n; i++ {
-		builder.Use(middleware)
-	}
-
-	config := strings.NewReader(`[ { "method": "GET", "path": "/path", "scope": [[]], "info": "info", "in": {}, "out": {} } ]`)
-	err := builder.Setup(config)
-	if err != nil {
-		t.Fatalf("setup: unexpected error <%v>", err)
-	}
-
-	pathHandler := func(ctx api.Ctx) (*struct{}, api.Err) {
-		// write value from middlewares into response
-		value := ctx.Req.Context().Value(key)
-		if value == nil {
-			t.Fatalf("nothing found in context")
-		}
-		cast, ok := value.(int)
-		if !ok {
-			t.Fatalf("cannot cast context data to int")
-		}
-		// write to response
-		ctx.Res.Write([]byte(fmt.Sprintf("#%d#", cast)))
-
-		return nil, api.ErrSuccess
-	}
-
-	if err := builder.Bind(http.MethodGet, "/path", pathHandler); err != nil {
-		t.Fatalf("bind: unexpected error <%v>", err)
-	}
-
-	handler, err := builder.Build()
-	if err != nil {
-		t.Fatalf("build: unexpected error <%v>", err)
-	}
-
-	response := httptest.NewRecorder()
-	request := httptest.NewRequest(http.MethodGet, "/path", &bytes.Buffer{})
-
-	// test request
-	handler.ServeHTTP(response, request)
-	if response.Body == nil {
-		t.Fatalf("response has no body")
-	}
-	token := fmt.Sprintf("#%d#", n)
-	if !strings.Contains(response.Body.String(), token) {
-		t.Fatalf("expected '%s' to be in response <%s>", token, response.Body.String())
-	}
-
-}
-
 func TestBind(t *testing.T) {
 	tcases := []struct {
 		Name          string

handler.go

@@ -13,7 +13,7 @@ type Handler Builder
 
 // ServeHTTP implements http.Handler and wraps it in middlewares (adapters)
 func (s Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	var h = http.HandlerFunc(s.handleRequest)
+	var h = http.HandlerFunc(s.resolve)
 
 	for _, adapter := range s.adapters {
 		h = adapter(h)
@@ -21,7 +21,7 @@ func (s Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	h(w, r)
 }
 
-func (s Handler) handleRequest(w http.ResponseWriter, r *http.Request) {
+func (s Handler) resolve(w http.ResponseWriter, r *http.Request) {
 	// 1. find a matching service from config
 	var service = s.conf.Find(r)
 	if service == nil {
@@ -50,6 +50,29 @@ func (s Handler) handleRequest(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	var auth = api.Auth{
+		Required: service.Scope,
+		Active:   []string{},
+	}
+
+	// 5. run auth-aware middlewares
+	var h = api.AuthHandlerFunc(func(a api.Auth, w http.ResponseWriter, r *http.Request) {
+		if !a.Granted() {
+			handleError(api.ErrPermission, w, r)
+			return
+		}
+
+		s.handle(input, handler, service, w, r)
+	})
+
+	for _, adapter := range s.authAdapters {
+		h = adapter(h)
+	}
+	h(auth, w, r)
+
+}
+
+func (s *Handler) handle(input *reqdata.T, handler *apiHandler, service *config.Service, w http.ResponseWriter, r *http.Request) {
 	// 5. pass execution to the handler
 	ctx := api.Ctx{Res: w, Req: r}
 	var outData, outErr = handler.dyn.Handle(ctx, input.Data)

handler_test.go

@@ -0,0 +1,241 @@
+package aicra
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"git.xdrm.io/go/aicra/api"
+)
+
+func TestWith(t *testing.T) {
+	builder := &Builder{}
+	if err := addBuiltinTypes(builder); err != nil {
+		t.Fatalf("unexpected error <%v>", err)
+	}
+
+	// build @n middlewares that take data from context and increment it
+	n := 1024
+
+	type ckey int
+	const key ckey = 0
+
+	middleware := func(next http.HandlerFunc) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+			newr := r
+
+			// first time -> store 1
+			value := r.Context().Value(key)
+			if value == nil {
+				newr = r.WithContext(context.WithValue(r.Context(), key, int(1)))
+				next(w, newr)
+				return
+			}
+
+			// get value and increment
+			cast, ok := value.(int)
+			if !ok {
+				t.Fatalf("value is not an int")
+			}
+			cast++
+			newr = r.WithContext(context.WithValue(r.Context(), key, cast))
+			next(w, newr)
+		}
+	}
+
+	// add middleware @n times
+	for i := 0; i < n; i++ {
+		builder.With(middleware)
+	}
+
+	config := strings.NewReader(`[ { "method": "GET", "path": "/path", "scope": [[]], "info": "info", "in": {}, "out": {} } ]`)
+	err := builder.Setup(config)
+	if err != nil {
+		t.Fatalf("setup: unexpected error <%v>", err)
+	}
+
+	pathHandler := func(ctx api.Ctx) (*struct{}, api.Err) {
+		// write value from middlewares into response
+		value := ctx.Req.Context().Value(key)
+		if value == nil {
+			t.Fatalf("nothing found in context")
+		}
+		cast, ok := value.(int)
+		if !ok {
+			t.Fatalf("cannot cast context data to int")
+		}
+		// write to response
+		ctx.Res.Write([]byte(fmt.Sprintf("#%d#", cast)))
+
+		return nil, api.ErrSuccess
+	}
+
+	if err := builder.Bind(http.MethodGet, "/path", pathHandler); err != nil {
+		t.Fatalf("bind: unexpected error <%v>", err)
+	}
+
+	handler, err := builder.Build()
+	if err != nil {
+		t.Fatalf("build: unexpected error <%v>", err)
+	}
+
+	response := httptest.NewRecorder()
+	request := httptest.NewRequest(http.MethodGet, "/path", &bytes.Buffer{})
+
+	// test request
+	handler.ServeHTTP(response, request)
+	if response.Body == nil {
+		t.Fatalf("response has no body")
+	}
+	token := fmt.Sprintf("#%d#", n)
+	if !strings.Contains(response.Body.String(), token) {
+		t.Fatalf("expected '%s' to be in response <%s>", token, response.Body.String())
+	}
+
+}
+
+func TestWithAuth(t *testing.T) {
+
+	tt := []struct {
+		name        string
+		manifest    string
+		permissions []string
+		granted     bool
+	}{
+		{
+			name:        "provide only requirement A",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A"},
+			granted:     true,
+		},
+		{
+			name:        "missing requirement",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{},
+			granted:     false,
+		},
+		{
+			name:        "missing requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A", "B"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{},
+			granted:     false,
+		},
+		{
+			name:        "missing some requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A", "B"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A"},
+			granted:     false,
+		},
+		{
+			name:        "provide requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A", "B"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A", "B"},
+			granted:     true,
+		},
+		{
+			name:        "missing OR requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A"], ["B"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"C"},
+			granted:     false,
+		},
+		{
+			name:        "provide 1 OR requirement",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A"], ["B"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A"},
+			granted:     true,
+		},
+		{
+			name:        "provide both OR requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A"], ["B"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A", "B"},
+			granted:     true,
+		},
+		{
+			name:        "missing composite OR requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A", "B"], ["C", "D"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{},
+			granted:     false,
+		},
+		{
+			name:        "missing partial composite OR requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A", "B"], ["C", "D"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A", "C"},
+			granted:     false,
+		},
+		{
+			name:        "provide 1 composite OR requirement",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A", "B"], ["C", "D"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A", "B", "C"},
+			granted:     true,
+		},
+		{
+			name:        "provide both composite OR requirements",
+			manifest:    `[ { "method": "GET", "path": "/path", "scope": [["A", "B"], ["C", "D"]], "info": "info", "in": {}, "out": {} } ]`,
+			permissions: []string{"A", "B", "C", "D"},
+			granted:     true,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			builder := &Builder{}
+			if err := addBuiltinTypes(builder); err != nil {
+				t.Fatalf("unexpected error <%v>", err)
+			}
+
+			// tester middleware (last executed)
+			builder.WithAuth(func(next api.AuthHandlerFunc) api.AuthHandlerFunc {
+				return func(a api.Auth, w http.ResponseWriter, r *http.Request) {
+					if a.Granted() == tc.granted {
+						return
+					}
+					if a.Granted() {
+						t.Fatalf("unexpected granted auth")
+					} else {
+						t.Fatalf("expected granted auth")
+					}
+				}
+			})
+
+			builder.WithAuth(func(next api.AuthHandlerFunc) api.AuthHandlerFunc {
+				return func(a api.Auth, w http.ResponseWriter, r *http.Request) {
+					a.Active = tc.permissions
+					next(a, w, r)
+				}
+			})
+
+			err := builder.Setup(strings.NewReader(tc.manifest))
+			if err != nil {
+				t.Fatalf("setup: unexpected error <%v>", err)
+			}
+
+			pathHandler := func(ctx api.Ctx) (*struct{}, api.Err) {
+				return nil, api.ErrNotImplemented
+			}
+
+			if err := builder.Bind(http.MethodGet, "/path", pathHandler); err != nil {
+				t.Fatalf("bind: unexpected error <%v>", err)
+			}
+
+			handler, err := builder.Build()
+			if err != nil {
+				t.Fatalf("build: unexpected error <%v>", err)
+			}
+
+			response := httptest.NewRecorder()
+			request := httptest.NewRequest(http.MethodGet, "/path", &bytes.Buffer{})
+
+			// test request
+			handler.ServeHTTP(response, request)
+			if response.Body == nil {
+				t.Fatalf("response has no body")
+			}
+
+		})
+	}
+
+}