-

internal/auth/permissions.go

@@ -0,0 +1,587 @@
+package auth
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/kms/api-key-service/internal/cache"
+	"github.com/kms/api-key-service/internal/config"
+	"github.com/kms/api-key-service/internal/errors"
+)
+
+// PermissionManager handles hierarchical permission management
+type PermissionManager struct {
+	config       config.ConfigProvider
+	logger       *zap.Logger
+	cacheManager *cache.CacheManager
+	hierarchy    *PermissionHierarchy
+}
+
+// NewPermissionManager creates a new permission manager
+func NewPermissionManager(config config.ConfigProvider, logger *zap.Logger) *PermissionManager {
+	cacheManager := cache.NewCacheManager(config, logger)
+	hierarchy := NewPermissionHierarchy()
+	
+	return &PermissionManager{
+		config:       config,
+		logger:       logger,
+		cacheManager: cacheManager,
+		hierarchy:    hierarchy,
+	}
+}
+
+// PermissionHierarchy represents the hierarchical permission structure
+type PermissionHierarchy struct {
+	permissions map[string]*Permission
+	roles       map[string]*Role
+}
+
+// Permission represents a single permission with its hierarchy
+type Permission struct {
+	Name        string   `json:"name"`
+	Description string   `json:"description"`
+	Parent      string   `json:"parent,omitempty"`
+	Children    []string `json:"children"`
+	Level       int      `json:"level"`
+	Resource    string   `json:"resource"`
+	Action      string   `json:"action"`
+}
+
+// Role represents a role with associated permissions
+type Role struct {
+	Name         string            `json:"name"`
+	Description  string            `json:"description"`
+	Permissions  []string          `json:"permissions"`
+	Inherits     []string          `json:"inherits"`
+	Metadata     map[string]string `json:"metadata"`
+}
+
+// PermissionEvaluation represents the result of permission evaluation
+type PermissionEvaluation struct {
+	Granted       bool              `json:"granted"`
+	Permission    string            `json:"permission"`
+	GrantedBy     []string          `json:"granted_by"`
+	DeniedReason  string            `json:"denied_reason,omitempty"`
+	Metadata      map[string]string `json:"metadata"`
+	EvaluatedAt   time.Time         `json:"evaluated_at"`
+}
+
+// BulkPermissionRequest represents a bulk permission operation request
+type BulkPermissionRequest struct {
+	UserID      string   `json:"user_id"`
+	AppID       string   `json:"app_id"`
+	Permissions []string `json:"permissions"`
+	Context     map[string]string `json:"context,omitempty"`
+}
+
+// BulkPermissionResponse represents a bulk permission operation response
+type BulkPermissionResponse struct {
+	UserID      string                          `json:"user_id"`
+	AppID       string                          `json:"app_id"`
+	Results     map[string]*PermissionEvaluation `json:"results"`
+	EvaluatedAt time.Time                       `json:"evaluated_at"`
+}
+
+// NewPermissionHierarchy creates a new permission hierarchy
+func NewPermissionHierarchy() *PermissionHierarchy {
+	h := &PermissionHierarchy{
+		permissions: make(map[string]*Permission),
+		roles:       make(map[string]*Role),
+	}
+	
+	// Initialize with default permissions
+	h.initializeDefaultPermissions()
+	h.initializeDefaultRoles()
+	
+	return h
+}
+
+// initializeDefaultPermissions sets up the default permission hierarchy
+func (h *PermissionHierarchy) initializeDefaultPermissions() {
+	defaultPermissions := []*Permission{
+		// Root permissions
+		{Name: "admin", Description: "Full administrative access", Level: 0, Resource: "*", Action: "*"},
+		{Name: "read", Description: "Read access", Level: 0, Resource: "*", Action: "read"},
+		{Name: "write", Description: "Write access", Level: 0, Resource: "*", Action: "write"},
+		
+		// Application permissions
+		{Name: "app.admin", Description: "Application administration", Parent: "admin", Level: 1, Resource: "application", Action: "*"},
+		{Name: "app.read", Description: "Read applications", Parent: "read", Level: 1, Resource: "application", Action: "read"},
+		{Name: "app.write", Description: "Modify applications", Parent: "write", Level: 1, Resource: "application", Action: "write"},
+		{Name: "app.create", Description: "Create applications", Parent: "app.write", Level: 2, Resource: "application", Action: "create"},
+		{Name: "app.update", Description: "Update applications", Parent: "app.write", Level: 2, Resource: "application", Action: "update"},
+		{Name: "app.delete", Description: "Delete applications", Parent: "app.write", Level: 2, Resource: "application", Action: "delete"},
+		
+		// Token permissions
+		{Name: "token.admin", Description: "Token administration", Parent: "admin", Level: 1, Resource: "token", Action: "*"},
+		{Name: "token.read", Description: "Read tokens", Parent: "read", Level: 1, Resource: "token", Action: "read"},
+		{Name: "token.write", Description: "Modify tokens", Parent: "write", Level: 1, Resource: "token", Action: "write"},
+		{Name: "token.create", Description: "Create tokens", Parent: "token.write", Level: 2, Resource: "token", Action: "create"},
+		{Name: "token.revoke", Description: "Revoke tokens", Parent: "token.write", Level: 2, Resource: "token", Action: "revoke"},
+		{Name: "token.verify", Description: "Verify tokens", Parent: "token.read", Level: 2, Resource: "token", Action: "verify"},
+		
+		// Permission permissions
+		{Name: "permission.admin", Description: "Permission administration", Parent: "admin", Level: 1, Resource: "permission", Action: "*"},
+		{Name: "permission.read", Description: "Read permissions", Parent: "read", Level: 1, Resource: "permission", Action: "read"},
+		{Name: "permission.write", Description: "Modify permissions", Parent: "write", Level: 1, Resource: "permission", Action: "write"},
+		{Name: "permission.grant", Description: "Grant permissions", Parent: "permission.write", Level: 2, Resource: "permission", Action: "grant"},
+		{Name: "permission.revoke", Description: "Revoke permissions", Parent: "permission.write", Level: 2, Resource: "permission", Action: "revoke"},
+		
+		// User permissions
+		{Name: "user.admin", Description: "User administration", Parent: "admin", Level: 1, Resource: "user", Action: "*"},
+		{Name: "user.read", Description: "Read user information", Parent: "read", Level: 1, Resource: "user", Action: "read"},
+		{Name: "user.write", Description: "Modify user information", Parent: "write", Level: 1, Resource: "user", Action: "write"},
+	}
+	
+	// Add permissions to hierarchy
+	for _, perm := range defaultPermissions {
+		h.permissions[perm.Name] = perm
+	}
+	
+	// Build parent-child relationships
+	h.buildHierarchy()
+}
+
+// initializeDefaultRoles sets up default roles
+func (h *PermissionHierarchy) initializeDefaultRoles() {
+	defaultRoles := []*Role{
+		{
+			Name:        "super_admin",
+			Description: "Super administrator with full access",
+			Permissions: []string{"admin"},
+			Metadata:    map[string]string{"level": "system"},
+		},
+		{
+			Name:        "app_admin",
+			Description: "Application administrator",
+			Permissions: []string{"app.admin", "token.admin", "user.read"},
+			Metadata:    map[string]string{"level": "application"},
+		},
+		{
+			Name:        "developer",
+			Description: "Developer with token management access",
+			Permissions: []string{"app.read", "token.create", "token.read", "token.revoke"},
+			Metadata:    map[string]string{"level": "developer"},
+		},
+		{
+			Name:        "viewer",
+			Description: "Read-only access",
+			Permissions: []string{"app.read", "token.read", "user.read"},
+			Metadata:    map[string]string{"level": "viewer"},
+		},
+		{
+			Name:        "token_manager",
+			Description: "Token management specialist",
+			Permissions: []string{"token.admin", "app.read"},
+			Metadata:    map[string]string{"level": "specialist"},
+		},
+	}
+	
+	for _, role := range defaultRoles {
+		h.roles[role.Name] = role
+	}
+}
+
+// buildHierarchy builds the parent-child relationships
+func (h *PermissionHierarchy) buildHierarchy() {
+	for _, perm := range h.permissions {
+		if perm.Parent != "" {
+			if parent, exists := h.permissions[perm.Parent]; exists {
+				parent.Children = append(parent.Children, perm.Name)
+			}
+		}
+	}
+}
+
+// HasPermission checks if a user has a specific permission
+func (pm *PermissionManager) HasPermission(ctx context.Context, userID, appID, permission string) (*PermissionEvaluation, error) {
+	pm.logger.Debug("Evaluating permission", 
+		zap.String("user_id", userID),
+		zap.String("app_id", appID),
+		zap.String("permission", permission))
+
+	// Check cache first
+	cacheKey := cache.CacheKey(cache.KeyPrefixPermission, fmt.Sprintf("%s:%s:%s", userID, appID, permission))
+	
+	var cached PermissionEvaluation
+	if err := pm.cacheManager.GetJSON(ctx, cacheKey, &cached); err == nil {
+		pm.logger.Debug("Permission evaluation found in cache", 
+			zap.String("permission", permission),
+			zap.Bool("granted", cached.Granted))
+		return &cached, nil
+	}
+
+	// Evaluate permission
+	evaluation := pm.evaluatePermission(ctx, userID, appID, permission)
+	
+	// Cache the result for 5 minutes
+	if err := pm.cacheManager.SetJSON(ctx, cacheKey, evaluation, 5*time.Minute); err != nil {
+		pm.logger.Warn("Failed to cache permission evaluation", zap.Error(err))
+	}
+
+	pm.logger.Debug("Permission evaluation completed", 
+		zap.String("permission", permission),
+		zap.Bool("granted", evaluation.Granted),
+		zap.Strings("granted_by", evaluation.GrantedBy))
+
+	return evaluation, nil
+}
+
+// EvaluateBulkPermissions evaluates multiple permissions at once
+func (pm *PermissionManager) EvaluateBulkPermissions(ctx context.Context, req *BulkPermissionRequest) (*BulkPermissionResponse, error) {
+	pm.logger.Debug("Evaluating bulk permissions", 
+		zap.String("user_id", req.UserID),
+		zap.String("app_id", req.AppID),
+		zap.Int("permission_count", len(req.Permissions)))
+
+	response := &BulkPermissionResponse{
+		UserID:      req.UserID,
+		AppID:       req.AppID,
+		Results:     make(map[string]*PermissionEvaluation),
+		EvaluatedAt: time.Now(),
+	}
+
+	// Evaluate each permission
+	for _, permission := range req.Permissions {
+		evaluation, err := pm.HasPermission(ctx, req.UserID, req.AppID, permission)
+		if err != nil {
+			pm.logger.Error("Failed to evaluate permission in bulk operation", 
+				zap.String("permission", permission),
+				zap.Error(err))
+			
+			// Create a denied evaluation for failed checks
+			evaluation = &PermissionEvaluation{
+				Granted:      false,
+				Permission:   permission,
+				DeniedReason: fmt.Sprintf("Evaluation error: %v", err),
+				EvaluatedAt:  time.Now(),
+			}
+		}
+		
+		response.Results[permission] = evaluation
+	}
+
+	pm.logger.Debug("Bulk permission evaluation completed", 
+		zap.String("user_id", req.UserID),
+		zap.Int("total_permissions", len(req.Permissions)),
+		zap.Int("granted_count", pm.countGrantedPermissions(response.Results)))
+
+	return response, nil
+}
+
+// evaluatePermission performs the actual permission evaluation
+func (pm *PermissionManager) evaluatePermission(ctx context.Context, userID, appID, permission string) *PermissionEvaluation {
+	evaluation := &PermissionEvaluation{
+		Permission:  permission,
+		EvaluatedAt: time.Now(),
+		Metadata:    make(map[string]string),
+	}
+
+	// TODO: In a real implementation, this would:
+	// 1. Fetch user roles from database
+	// 2. Resolve role permissions
+	// 3. Check hierarchical permissions
+	// 4. Apply context-specific rules
+	
+	// For now, implement basic logic
+	userRoles := pm.getUserRoles(ctx, userID, appID)
+	grantedBy := []string{}
+
+	// Check direct permission grants
+	if pm.hasDirectPermission(userID, appID, permission) {
+		grantedBy = append(grantedBy, "direct")
+	}
+
+	// Check role-based permissions
+	for _, role := range userRoles {
+		if pm.roleHasPermission(role, permission) {
+			grantedBy = append(grantedBy, fmt.Sprintf("role:%s", role))
+		}
+	}
+
+	// Check hierarchical permissions
+	if len(grantedBy) == 0 {
+		if inheritedPermissions := pm.getInheritedPermissions(permission); len(inheritedPermissions) > 0 {
+			for _, inherited := range inheritedPermissions {
+				for _, role := range userRoles {
+					if pm.roleHasPermission(role, inherited) {
+						grantedBy = append(grantedBy, fmt.Sprintf("inherited:%s", inherited))
+						break
+					}
+				}
+			}
+		}
+	}
+
+	evaluation.Granted = len(grantedBy) > 0
+	evaluation.GrantedBy = grantedBy
+
+	if !evaluation.Granted {
+		evaluation.DeniedReason = "No matching permissions or roles found"
+	}
+
+	// Add metadata
+	evaluation.Metadata["user_roles"] = strings.Join(userRoles, ",")
+	evaluation.Metadata["app_id"] = appID
+	evaluation.Metadata["evaluation_method"] = "hierarchical"
+
+	return evaluation
+}
+
+// getUserRoles retrieves user roles (placeholder implementation)
+func (pm *PermissionManager) getUserRoles(ctx context.Context, userID, appID string) []string {
+	// TODO: Implement actual role retrieval from database
+	// For now, return default roles based on user patterns
+	
+	if strings.Contains(userID, "admin") {
+		return []string{"super_admin"}
+	}
+	if strings.Contains(userID, "dev") {
+		return []string{"developer"}
+	}
+	return []string{"viewer"}
+}
+
+// hasDirectPermission checks if user has direct permission grant
+func (pm *PermissionManager) hasDirectPermission(userID, appID, permission string) bool {
+	// TODO: Implement database lookup for direct permission grants
+	return false
+}
+
+// roleHasPermission checks if a role has a specific permission
+func (pm *PermissionManager) roleHasPermission(roleName, permission string) bool {
+	role, exists := pm.hierarchy.roles[roleName]
+	if !exists {
+		return false
+	}
+
+	// Check direct permissions
+	for _, perm := range role.Permissions {
+		if perm == permission {
+			return true
+		}
+		
+		// Check if this permission grants the requested one through hierarchy
+		if pm.permissionIncludes(perm, permission) {
+			return true
+		}
+	}
+
+	// Check inherited roles
+	for _, inheritedRole := range role.Inherits {
+		if pm.roleHasPermission(inheritedRole, permission) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// permissionIncludes checks if a permission includes another through hierarchy
+func (pm *PermissionManager) permissionIncludes(granted, requested string) bool {
+	// Check if granted permission is a parent of requested permission
+	return pm.isPermissionParent(granted, requested)
+}
+
+// isPermissionParent checks if one permission is a parent of another
+func (pm *PermissionManager) isPermissionParent(parent, child string) bool {
+	childPerm, exists := pm.hierarchy.permissions[child]
+	if !exists {
+		return false
+	}
+
+	// Traverse up the hierarchy
+	current := childPerm.Parent
+	for current != "" {
+		if current == parent {
+			return true
+		}
+		
+		if currentPerm, exists := pm.hierarchy.permissions[current]; exists {
+			current = currentPerm.Parent
+		} else {
+			break
+		}
+	}
+
+	return false
+}
+
+// getInheritedPermissions gets permissions that could grant the requested permission
+func (pm *PermissionManager) getInheritedPermissions(permission string) []string {
+	var inherited []string
+	
+	perm, exists := pm.hierarchy.permissions[permission]
+	if !exists {
+		return inherited
+	}
+
+	// Get all parent permissions
+	current := perm.Parent
+	for current != "" {
+		inherited = append(inherited, current)
+		
+		if currentPerm, exists := pm.hierarchy.permissions[current]; exists {
+			current = currentPerm.Parent
+		} else {
+			break
+		}
+	}
+
+	return inherited
+}
+
+// countGrantedPermissions counts granted permissions in bulk results
+func (pm *PermissionManager) countGrantedPermissions(results map[string]*PermissionEvaluation) int {
+	count := 0
+	for _, eval := range results {
+		if eval.Granted {
+			count++
+		}
+	}
+	return count
+}
+
+// GetPermissionHierarchy returns the current permission hierarchy
+func (pm *PermissionManager) GetPermissionHierarchy() *PermissionHierarchy {
+	return pm.hierarchy
+}
+
+// AddPermission adds a new permission to the hierarchy
+func (pm *PermissionManager) AddPermission(permission *Permission) error {
+	if permission.Name == "" {
+		return errors.NewValidationError("Permission name is required")
+	}
+
+	// Validate parent exists if specified
+	if permission.Parent != "" {
+		if _, exists := pm.hierarchy.permissions[permission.Parent]; !exists {
+			return errors.NewValidationError(fmt.Sprintf("Parent permission '%s' does not exist", permission.Parent))
+		}
+	}
+
+	pm.hierarchy.permissions[permission.Name] = permission
+	pm.hierarchy.buildHierarchy()
+
+	pm.logger.Info("Permission added to hierarchy", 
+		zap.String("permission", permission.Name),
+		zap.String("parent", permission.Parent))
+
+	return nil
+}
+
+// AddRole adds a new role to the system
+func (pm *PermissionManager) AddRole(role *Role) error {
+	if role.Name == "" {
+		return errors.NewValidationError("Role name is required")
+	}
+
+	// Validate permissions exist
+	for _, perm := range role.Permissions {
+		if _, exists := pm.hierarchy.permissions[perm]; !exists {
+			return errors.NewValidationError(fmt.Sprintf("Permission '%s' does not exist", perm))
+		}
+	}
+
+	// Validate inherited roles exist
+	for _, inheritedRole := range role.Inherits {
+		if _, exists := pm.hierarchy.roles[inheritedRole]; !exists {
+			return errors.NewValidationError(fmt.Sprintf("Inherited role '%s' does not exist", inheritedRole))
+		}
+	}
+
+	pm.hierarchy.roles[role.Name] = role
+
+	pm.logger.Info("Role added to system", 
+		zap.String("role", role.Name),
+		zap.Strings("permissions", role.Permissions))
+
+	return nil
+}
+
+// ListPermissions returns all permissions sorted by hierarchy
+func (pm *PermissionManager) ListPermissions() []*Permission {
+	permissions := make([]*Permission, 0, len(pm.hierarchy.permissions))
+	
+	for _, perm := range pm.hierarchy.permissions {
+		permissions = append(permissions, perm)
+	}
+
+	// Sort by level and name
+	sort.Slice(permissions, func(i, j int) bool {
+		if permissions[i].Level != permissions[j].Level {
+			return permissions[i].Level < permissions[j].Level
+		}
+		return permissions[i].Name < permissions[j].Name
+	})
+
+	return permissions
+}
+
+// ListRoles returns all roles
+func (pm *PermissionManager) ListRoles() []*Role {
+	roles := make([]*Role, 0, len(pm.hierarchy.roles))
+	
+	for _, role := range pm.hierarchy.roles {
+		roles = append(roles, role)
+	}
+
+	// Sort by name
+	sort.Slice(roles, func(i, j int) bool {
+		return roles[i].Name < roles[j].Name
+	})
+
+	return roles
+}
+
+// InvalidatePermissionCache invalidates cached permission evaluations for a user
+func (pm *PermissionManager) InvalidatePermissionCache(ctx context.Context, userID, appID string) error {
+	// In a real implementation, this would invalidate all cached permissions for the user
+	// For now, we'll just log the operation
+	
+	pm.logger.Info("Invalidating permission cache", 
+		zap.String("user_id", userID),
+		zap.String("app_id", appID))
+
+	return nil
+}
+
+// ListPermissions returns all permissions sorted by hierarchy (for PermissionHierarchy)
+func (h *PermissionHierarchy) ListPermissions() []*Permission {
+	permissions := make([]*Permission, 0, len(h.permissions))
+	
+	for _, perm := range h.permissions {
+		permissions = append(permissions, perm)
+	}
+
+	// Sort by level and name
+	sort.Slice(permissions, func(i, j int) bool {
+		if permissions[i].Level != permissions[j].Level {
+			return permissions[i].Level < permissions[j].Level
+		}
+		return permissions[i].Name < permissions[j].Name
+	})
+
+	return permissions
+}
+
+// ListRoles returns all roles (for PermissionHierarchy)
+func (h *PermissionHierarchy) ListRoles() []*Role {
+	roles := make([]*Role, 0, len(h.roles))
+	
+	for _, role := range h.roles {
+		roles = append(roles, role)
+	}
+
+	// Sort by name
+	sort.Slice(roles, func(i, j int) bool {
+		return roles[i].Name < roles[j].Name
+	})
+
+	return roles
+}