Mise en place d'un système de vérification des autorisations côté

serveur

- Création d'un service d'autorisation dynamique basé sur des "voter" (à
  la Symfony)
- Mise en place des autorisations sur les principales queries/mutations
  de l'API GraphQL

cmd/server/container.go

@@ -5,6 +5,9 @@ import (
 	"net/http"
 	"time"
 
+	"forge.cadoles.com/Cadoles/daddy/internal/model"
+	"forge.cadoles.com/Cadoles/daddy/internal/voter"
+
 	"github.com/wader/gormstore"
 
 	"forge.cadoles.com/Cadoles/daddy/internal/auth"
@@ -99,5 +102,11 @@ func getServiceContainer(ctx context.Context, conf *config.Config) (*service.Con
 
 	ctn.Provide(auth.ServiceName, auth.ServiceProvider(conf.Auth.Rules))
 
+	ctn.Provide(voter.ServiceName, voter.ServiceProvider(
+		voter.StrategyUnanimous,
+		model.NewDecisionSupportFileVoter(),
+		model.NewWorkgroupVoter(),
+	))
+
 	return ctn, nil
 }

internal/config/config.go

@@ -90,7 +90,7 @@ func NewDefault() *Config {
 			Address:                 ":8081",
 			CookieAuthenticationKey: "",
 			CookieEncryptionKey:     "",
-			CookieMaxAge:            int((time.Hour * 1).Seconds()), // 1 hour
+			CookieMaxAge:            int((time.Hour * 24).Seconds()), // 24 hours
 			TemplateDir:             "template",
 			PublicDir:               "public",
 			FrontendURL:             "http://localhost:8080",

internal/graph/dsf_handler.go

@@ -12,6 +12,15 @@ import (
 )
 
 func handleCreateDecisionSupportFile(ctx context.Context, changes *model.DecisionSupportFileChanges) (*model.DecisionSupportFile, error) {
+	authorized, err := isAuthorized(ctx, &model.DecisionSupportFile{}, model.ActionCreate)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	if !authorized {
+		return nil, errs.WithStack(ErrForbidden)
+	}
+
 	ctn := container.Must(ctx)
 	db := orm.Must(ctn).DB()
 
@@ -31,7 +40,21 @@ func handleUpdateDecisionSupportFile(ctx context.Context, id string, changes *mo
 
 	repo := model.NewDSFRepository(db)
 
-	dsf, err := repo.Update(ctx, id, changes)
+	dsf, err := repo.Find(ctx, id)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	authorized, err := isAuthorized(ctx, dsf, model.ActionUpdate)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	if !authorized {
+		return nil, errs.WithStack(ErrForbidden)
+	}
+
+	dsf, err = repo.Update(ctx, id, changes)
 	if err != nil {
 		return nil, errs.WithStack(err)
 	}
@@ -45,7 +68,25 @@ func handleDecisionSupportFiles(ctx context.Context, filter *model.DecisionSuppo
 
 	repo := model.NewDSFRepository(db)
 
-	return repo.Search(ctx, filter)
+	found, err := repo.Search(ctx, filter)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	dsfs := make([]*model.DecisionSupportFile, 0)
+
+	for _, d := range found {
+		authorized, err := isAuthorized(ctx, d, model.ActionRead)
+		if err != nil {
+			return nil, errs.WithStack(err)
+		}
+
+		if authorized {
+			dsfs = append(dsfs, d)
+		}
+	}
+
+	return dsfs, nil
 }
 
 func handleSections(ctx context.Context, dsf *model.DecisionSupportFile) (map[string]interface{}, error) {

internal/graph/error.go

@@ -0,0 +1,7 @@
+package graph
+
+import "errors"
+
+var (
+	ErrForbidden = errors.New("forbidden")
+)

internal/graph/helper.go

@@ -3,6 +3,8 @@ package graph
 import (
 	"context"
 
+	"forge.cadoles.com/Cadoles/daddy/internal/voter"
+
 	"forge.cadoles.com/Cadoles/daddy/internal/model"
 	"forge.cadoles.com/Cadoles/daddy/internal/orm"
 	"forge.cadoles.com/Cadoles/daddy/internal/session"
@@ -46,3 +48,31 @@ func getSessionUser(ctx context.Context) (*model.User, *gorm.DB, error) {
 
 	return user, db, nil
 }
+
+func isAuthorized(ctx context.Context, obj interface{}, action interface{}) (bool, error) {
+	user, _, err := getSessionUser(ctx)
+	if err != nil {
+		return false, errors.WithStack(err)
+	}
+
+	ctn, err := container.From(ctx)
+	if err != nil {
+		return false, errors.WithStack(err)
+	}
+
+	voterSrv, err := voter.From(ctn)
+	if err != nil {
+		return false, errors.WithStack(err)
+	}
+
+	decision, err := voterSrv.Authorized(ctx, user, obj, action)
+	if err != nil {
+		return false, errors.WithStack(err)
+	}
+
+	if decision == voter.Allow {
+		return true, nil
+	}
+
+	return false, nil
+}

internal/graph/workgroup_handler.go

@@ -2,10 +2,10 @@ package graph
 
 import (
 	"context"
-	"strconv"
 
 	"forge.cadoles.com/Cadoles/daddy/internal/model"
 	"github.com/pkg/errors"
+	errs "github.com/pkg/errors"
 )
 
 func handleWorkgroups(ctx context.Context, filter *model.WorkgroupsFilter) ([]*model.Workgroup, error) {
@@ -24,20 +24,28 @@ func handleWorkgroups(ctx context.Context, filter *model.WorkgroupsFilter) ([]*m
 		}
 	}
 
-	workgroups, err := repo.FindWorkgroups(ctx, criteria...)
+	found, err := repo.FindWorkgroups(ctx, criteria...)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
 
+	workgroups := make([]*model.Workgroup, 0)
+
+	for _, wg := range found {
+		authorized, err := isAuthorized(ctx, wg, model.ActionRead)
+		if err != nil {
+			return nil, errs.WithStack(err)
+		}
+
+		if authorized {
+			workgroups = append(workgroups, wg)
+		}
+	}
+
 	return workgroups, nil
 }
 
 func handleJoinWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Workgroup, error) {
-	workgroupID, err := parseWorkgroupID(rawWorkgroupID)
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
 	user, db, err := getSessionUser(ctx)
 	if err != nil {
 		return nil, errors.WithStack(err)
@@ -45,7 +53,21 @@ func handleJoinWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Wor
 
 	repo := model.NewWorkgroupRepository(db)
 
-	workgroup, err := repo.AddUserToWorkgroup(ctx, user.ID, workgroupID)
+	workgroup, err := repo.Find(ctx, rawWorkgroupID)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	authorized, err := isAuthorized(ctx, workgroup, model.ActionJoin)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	if !authorized {
+		return nil, errs.WithStack(ErrForbidden)
+	}
+
+	workgroup, err = repo.AddUserToWorkgroup(ctx, user.ID, workgroup.ID)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -53,12 +75,7 @@ func handleJoinWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Wor
 	return workgroup, nil
 }
 
-func handleLeaveWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Workgroup, error) {
-	workgroupID, err := parseWorkgroupID(rawWorkgroupID)
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
+func handleLeaveWorkgroup(ctx context.Context, workgroupID string) (*model.Workgroup, error) {
 	user, db, err := getSessionUser(ctx)
 	if err != nil {
 		return nil, errors.WithStack(err)
@@ -66,7 +83,21 @@ func handleLeaveWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Wo
 
 	repo := model.NewWorkgroupRepository(db)
 
-	workgroup, err := repo.RemoveUserFromWorkgroup(ctx, user.ID, workgroupID)
+	workgroup, err := repo.Find(ctx, workgroupID)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	authorized, err := isAuthorized(ctx, workgroup, model.ActionLeave)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	if !authorized {
+		return nil, errs.WithStack(ErrForbidden)
+	}
+
+	workgroup, err = repo.RemoveUserFromWorkgroup(ctx, user.ID, workgroup.ID)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -75,6 +106,15 @@ func handleLeaveWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Wo
 }
 
 func handleCreateWorkgroup(ctx context.Context, changes model.WorkgroupChanges) (*model.Workgroup, error) {
+	authorized, err := isAuthorized(ctx, &model.Workgroup{}, model.ActionCreate)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	if !authorized {
+		return nil, errs.WithStack(ErrForbidden)
+	}
+
 	db, err := getDB(ctx)
 	if err != nil {
 		return nil, errors.WithStack(err)
@@ -90,12 +130,7 @@ func handleCreateWorkgroup(ctx context.Context, changes model.WorkgroupChanges)
 	return workgroup, nil
 }
 
-func handleCloseWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Workgroup, error) {
-	workgroupID, err := parseWorkgroupID(rawWorkgroupID)
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
+func handleCloseWorkgroup(ctx context.Context, workgroupID string) (*model.Workgroup, error) {
 	db, err := getDB(ctx)
 	if err != nil {
 		return nil, errors.WithStack(err)
@@ -103,7 +138,21 @@ func handleCloseWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Wo
 
 	repo := model.NewWorkgroupRepository(db)
 
-	workgroup, err := repo.CloseWorkgroup(ctx, workgroupID)
+	workgroup, err := repo.Find(ctx, workgroupID)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	authorized, err := isAuthorized(ctx, workgroup, model.ActionClose)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	if !authorized {
+		return nil, errs.WithStack(ErrForbidden)
+	}
+
+	workgroup, err = repo.CloseWorkgroup(ctx, workgroup.ID)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -111,12 +160,7 @@ func handleCloseWorkgroup(ctx context.Context, rawWorkgroupID string) (*model.Wo
 	return workgroup, nil
 }
 
-func handleUpdateWorkgroup(ctx context.Context, rawWorkgroupID string, changes model.WorkgroupChanges) (*model.Workgroup, error) {
-	workgroupID, err := parseWorkgroupID(rawWorkgroupID)
-	if err != nil {
-		return nil, errors.WithStack(err)
-	}
-
+func handleUpdateWorkgroup(ctx context.Context, workgroupID string, changes model.WorkgroupChanges) (*model.Workgroup, error) {
 	db, err := getDB(ctx)
 	if err != nil {
 		return nil, errors.WithStack(err)
@@ -124,19 +168,24 @@ func handleUpdateWorkgroup(ctx context.Context, rawWorkgroupID string, changes m
 
 	repo := model.NewWorkgroupRepository(db)
 
-	workgroup, err := repo.UpdateWorkgroup(ctx, workgroupID, changes)
+	workgroup, err := repo.Find(ctx, workgroupID)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	authorized, err := isAuthorized(ctx, workgroup, model.ActionUpdate)
+	if err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	if !authorized {
+		return nil, errs.WithStack(ErrForbidden)
+	}
+
+	workgroup, err = repo.UpdateWorkgroup(ctx, workgroup.ID, changes)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
 
 	return workgroup, nil
 }
-
-func parseWorkgroupID(workgroupID string) (uint, error) {
-	workgroupID64, err := strconv.ParseUint(workgroupID, 10, 32)
-	if err != nil {
-		return 0, errors.WithStack(err)
-	}
-
-	return uint(workgroupID64), nil
-}

internal/model/action.go

@@ -0,0 +1,13 @@
+package model
+
+type Action string
+
+const (
+	ActionCreate Action = "create"
+	ActionRead   Action = "read"
+	ActionUpdate Action = "update"
+	ActionDelete Action = "delete"
+	ActionJoin   Action = "join"
+	ActionLeave  Action = "leave"
+	ActionClose  Action = "close"
+)

internal/model/dsf_repository.go

@@ -88,6 +88,17 @@ func (r *DSFRepository) updateFromChanges(dsf *DecisionSupportFile, changes *Dec
 	return nil
 }
 
+func (r *DSFRepository) Find(ctx context.Context, id string) (*DecisionSupportFile, error) {
+	dsf := &DecisionSupportFile{}
+	query := r.db.Model(dsf).Preload("Workgroup").Where("id = ?", id)
+
+	if err := query.First(&dsf).Error; err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	return dsf, nil
+}
+
 func (r *DSFRepository) Search(ctx context.Context, filter *DecisionSupportFileFilter) ([]*DecisionSupportFile, error) {
 	query := r.db.Model(&DecisionSupportFile{}).Preload("Workgroup")
 

internal/model/dsf_voter.go

@@ -0,0 +1,48 @@
+package model
+
+import (
+	"context"
+
+	"forge.cadoles.com/Cadoles/daddy/internal/voter"
+)
+
+type DecisionSupportFileVoter struct {
+}
+
+func (v *DecisionSupportFileVoter) Vote(ctx context.Context, subject interface{}, obj interface{}, act interface{}) (voter.Decision, error) {
+	user, ok := subject.(*User)
+	if !ok {
+		return voter.Abstain, nil
+	}
+
+	dsf, ok := obj.(*DecisionSupportFile)
+	if !ok {
+		return voter.Abstain, nil
+	}
+
+	action, ok := act.(Action)
+	if !ok {
+		return voter.Abstain, nil
+	}
+
+	switch action {
+	case ActionCreate:
+		return voter.Allow, nil
+	case ActionRead:
+		return voter.Allow, nil
+	case ActionUpdate:
+		if inWorkgroup(user, dsf.Workgroup) {
+			return voter.Allow, nil
+		}
+
+		return voter.Deny, nil
+	case ActionDelete:
+		return voter.Deny, nil
+	}
+
+	return voter.Abstain, nil
+}
+
+func NewDecisionSupportFileVoter() *DecisionSupportFileVoter {
+	return &DecisionSupportFileVoter{}
+}

internal/model/helper.go

@@ -0,0 +1,15 @@
+package model
+
+func inWorkgroup(user *User, workgroup *Workgroup) bool {
+	if workgroup == nil {
+		return false
+	}
+
+	for _, w := range user.Workgroups {
+		if w.ID == workgroup.ID {
+			return true
+		}
+	}
+
+	return false
+}

internal/model/workgroup_repository.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/jinzhu/gorm"
 	"github.com/pkg/errors"
+	errs "github.com/pkg/errors"
 )
 
 type WorkgroupRepository struct {
@@ -135,6 +136,17 @@ func (r *WorkgroupRepository) RemoveUserFromWorkgroup(ctx context.Context, userI
 	return workgroup, nil
 }
 
+func (r *WorkgroupRepository) Find(ctx context.Context, id string) (*Workgroup, error) {
+	wg := &Workgroup{}
+	query := r.db.Model(wg).Where("id = ?", id)
+
+	if err := query.First(&wg).Error; err != nil {
+		return nil, errs.WithStack(err)
+	}
+
+	return wg, nil
+}
+
 func NewWorkgroupRepository(db *gorm.DB) *WorkgroupRepository {
 	return &WorkgroupRepository{db}
 }

internal/model/workgroup_voter.go

@@ -0,0 +1,54 @@
+package model
+
+import (
+	"context"
+
+	"forge.cadoles.com/Cadoles/daddy/internal/voter"
+)
+
+type WorkgroupVoter struct {
+}
+
+func (v *WorkgroupVoter) Vote(ctx context.Context, subject interface{}, obj interface{}, act interface{}) (voter.Decision, error) {
+	user, ok := subject.(*User)
+	if !ok {
+		return voter.Abstain, nil
+	}
+
+	workgroup, ok := obj.(*Workgroup)
+	if !ok {
+		return voter.Abstain, nil
+	}
+
+	action, ok := act.(Action)
+	if !ok {
+		return voter.Abstain, nil
+	}
+
+	switch action {
+	case ActionCreate:
+		return voter.Allow, nil
+	case ActionRead:
+		return voter.Allow, nil
+	case ActionJoin:
+		return voter.Allow, nil
+	case ActionLeave:
+		fallthrough
+	case ActionUpdate:
+		fallthrough
+	case ActionClose:
+		if inWorkgroup(user, workgroup) {
+			return voter.Allow, nil
+		} else {
+			return voter.Deny, nil
+		}
+	case ActionDelete:
+		return voter.Deny, nil
+	}
+
+	return voter.Abstain, nil
+}
+
+func NewWorkgroupVoter() *WorkgroupVoter {
+	return &WorkgroupVoter{}
+}

internal/route/mount.go

@@ -36,10 +36,12 @@ func Mount(r *chi.Mux, config *config.Config) error {
 		}).Handler)
 		r.Use(session.UserEmailMiddleware)
 
-		gql := handler.New(
-			generated.NewExecutableSchema(generated.Config{
+		gqlConfig := generated.Config{
 			Resolvers: &graph.Resolver{},
-			}),
+		}
+
+		gql := handler.New(
+			generated.NewExecutableSchema(gqlConfig),
 		)
 
 		gql.AddTransport(transport.POST{})

internal/voter/decision.go

@@ -0,0 +1,22 @@
+package voter
+
+type Decision int
+
+const (
+	Allow Decision = iota
+	Deny
+	Abstain
+)
+
+func AsString(d Decision) string {
+	switch d {
+	case Allow:
+		return "allow"
+	case Deny:
+		return "deny"
+	case Abstain:
+		return "abstain"
+	default:
+		return "unknown"
+	}
+}

internal/voter/manager.go

@@ -0,0 +1,64 @@
+package voter
+
+import (
+	"context"
+
+	"github.com/davecgh/go-spew/spew"
+
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
+)
+
+type Voter interface {
+	Vote(ctx context.Context, subject interface{}, obj interface{}, action interface{}) (Decision, error)
+}
+
+type Strategy func(ctx context.Context, decisions []Decision) (Decision, error)
+
+type Manager struct {
+	strategy Strategy
+	voters   []Voter
+}
+
+func (m *Manager) Authorized(ctx context.Context, subject interface{}, obj interface{}, action interface{}) (Decision, error) {
+	decisions := make([]Decision, 0, len(m.voters))
+
+	logger.Debug(
+		ctx,
+		"checking authorization",
+		logger.F("subject", subject),
+		logger.F("object", obj),
+		logger.F("action", action),
+	)
+
+	for _, v := range m.voters {
+		dec, err := v.Vote(ctx, subject, obj, action)
+		if err != nil {
+			return Deny, errors.WithStack(err)
+		}
+
+		decisions = append(decisions, dec)
+	}
+
+	spew.Dump(decisions)
+
+	result, err := m.strategy(ctx, decisions)
+	if err != nil {
+		return Deny, errors.WithStack(err)
+	}
+
+	logger.Debug(
+		ctx,
+		"authorization checked",
+		logger.F("subject", subject),
+		logger.F("object", obj),
+		logger.F("action", action),
+		logger.F("result", AsString(result)),
+	)
+
+	return result, nil
+}
+
+func NewManager(strategy Strategy, voters ...Voter) *Manager {
+	return &Manager{strategy, voters}
+}

internal/voter/provider.go

@@ -0,0 +1,13 @@
+package voter
+
+import (
+	"gitlab.com/wpetit/goweb/service"
+)
+
+func ServiceProvider(strategy Strategy, voters ...Voter) service.Provider {
+	manager := NewManager(strategy, voters...)
+
+	return func(ctn *service.Container) (interface{}, error) {
+		return manager, nil
+	}
+}

internal/voter/service.go

@@ -0,0 +1,33 @@
+package voter
+
+import (
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/service"
+)
+
+const ServiceName service.Name = "voter"
+
+// From retrieves the voter service in the given container.
+func From(container *service.Container) (*Manager, error) {
+	service, err := container.Service(ServiceName)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error while retrieving '%s' service", ServiceName)
+	}
+
+	srv, ok := service.(*Manager)
+	if !ok {
+		return nil, errors.Errorf("retrieved service is not a valid '%s' service", ServiceName)
+	}
+
+	return srv, nil
+}
+
+// Must retrieves the voter service in the given container or panic otherwise.
+func Must(container *service.Container) *Manager {
+	srv, err := From(container)
+	if err != nil {
+		panic(err)
+	}
+
+	return srv
+}

internal/voter/strategy.go

@@ -0,0 +1,77 @@
+package voter
+
+import "context"
+
+// StrategyUnanimous returns Allow if all voters allow the operations.
+func StrategyUnanimous(ctx context.Context, decisions []Decision) (Decision, error) {
+	allAbstains := true
+
+	for _, d := range decisions {
+		if d == Deny {
+			return Deny, nil
+		}
+
+		if d != Abstain {
+			allAbstains = false
+		}
+	}
+
+	if allAbstains {
+		return Abstain, nil
+	}
+
+	return Allow, nil
+}
+
+// StrategyAffirmative returns Allow if at least one voter allow the operation.
+func StrategyAffirmative(ctx context.Context, decisions []Decision) (Decision, error) {
+	allAbstains := true
+
+	for _, d := range decisions {
+		if d == Allow {
+			return Allow, nil
+		}
+
+		if allAbstains && d != Abstain {
+			allAbstains = false
+		}
+	}
+
+	if allAbstains {
+		return Abstain, nil
+	}
+
+	return Deny, nil
+}
+
+// StrategyConsensus returns Allow if the majority of voters allow the operation.
+func StrategyConsensus(ctx context.Context, decisions []Decision) (Decision, error) {
+	deny := 0
+	allow := 0
+	abstain := 0
+
+	for _, d := range decisions {
+		switch {
+		case d == Allow:
+			allow++
+		case d == Deny:
+			deny++
+		case d == Abstain:
+			abstain++
+		}
+	}
+
+	if abstain > allow && abstain > deny {
+		return Abstain, nil
+	}
+
+	if allow > abstain && allow > deny {
+		return Allow, nil
+	}
+
+	if deny > allow && deny > abstain {
+		return Deny, nil
+	}
+
+	return Abstain, nil
+}

internal/voter/strategy_test.go

@@ -0,0 +1,125 @@
+package voter
+
+import (
+	"context"
+	"testing"
+)
+
+func TestStrategyUnanimous(t *testing.T) {
+	testCases := []struct {
+		Decisions []Decision
+		Expect    Decision
+	}{
+		{
+			Decisions: []Decision{Allow, Allow, Allow},
+			Expect:    Allow,
+		},
+		{
+			Decisions: []Decision{Abstain, Abstain, Abstain},
+			Expect:    Abstain,
+		},
+		{
+			Decisions: []Decision{Deny, Abstain, Abstain},
+			Expect:    Deny,
+		},
+		{
+			Decisions: []Decision{Deny, Allow, Abstain},
+			Expect:    Deny,
+		},
+	}
+
+	for _, tc := range testCases {
+		ctx := context.Background()
+
+		result, err := StrategyUnanimous(ctx, tc.Decisions)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if e, g := tc.Expect, result; e != g {
+			t.Errorf("result: expected '%v', got '%v'", AsString(e), AsString(g))
+		}
+	}
+}
+
+func TestStrategyAffirmative(t *testing.T) {
+	testCases := []struct {
+		Decisions []Decision
+		Expect    Decision
+	}{
+		{
+			Decisions: []Decision{Allow, Allow, Allow},
+			Expect:    Allow,
+		},
+		{
+			Decisions: []Decision{Abstain, Abstain, Abstain},
+			Expect:    Abstain,
+		},
+		{
+			Decisions: []Decision{Deny, Abstain, Abstain},
+			Expect:    Deny,
+		},
+		{
+			Decisions: []Decision{Deny, Allow, Abstain},
+			Expect:    Allow,
+		},
+	}
+
+	for _, tc := range testCases {
+		ctx := context.Background()
+
+		result, err := StrategyAffirmative(ctx, tc.Decisions)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if e, g := tc.Expect, result; e != g {
+			t.Errorf("result: expected '%v', got '%v'", AsString(e), AsString(g))
+		}
+	}
+}
+
+func TestStrategyConsensus(t *testing.T) {
+	testCases := []struct {
+		Decisions []Decision
+		Expect    Decision
+	}{
+		{
+			Decisions: []Decision{Allow, Allow, Allow},
+			Expect:    Allow,
+		},
+		{
+			Decisions: []Decision{Abstain, Abstain, Abstain},
+			Expect:    Abstain,
+		},
+		{
+			Decisions: []Decision{Deny, Allow, Abstain},
+			Expect:    Abstain,
+		},
+		{
+			Decisions: []Decision{Deny, Deny, Allow},
+			Expect:    Deny,
+		},
+		{
+			Decisions: []Decision{Deny, Deny, Allow, Allow},
+			Expect:    Abstain,
+		},
+		{
+			Decisions: []Decision{Deny, Deny, Allow, Allow, Allow},
+			Expect:    Allow,
+		},
+	}
+
+	for _, tc := range testCases {
+		ctx := context.Background()
+
+		result, err := StrategyConsensus(ctx, tc.Decisions)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if e, g := tc.Expect, result; e != g {
+			t.Errorf("result: expected '%v', got '%v'", AsString(e), AsString(g))
+		}
+	}
+}