Рыба проекта. Минимальная функциональность

pkg/domain/crypto/registry.go

@@ -0,0 +1,84 @@
+package crypto
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+)
+
+// Sentinel errors for registry operations.
+var (
+	ErrUnknownScheme   = errors.New("unknown KEM scheme")
+	ErrDuplicateScheme = errors.New("duplicate KEM scheme registration")
+)
+
+// KEMFactory is a constructor function that returns a fresh KEM instance.
+type KEMFactory func() KEM
+
+// Registry is a concurrent-safe map of KEM scheme IDs to their factories.
+type Registry interface {
+	Register(
+		schemeID uint16,
+		factory KEMFactory,
+	) error
+	Lookup(
+		schemeID uint16,
+	) (
+		KEMFactory,
+		error,
+	)
+}
+
+// registry is the private implementation of Registry.
+type registry struct {
+	mutex     sync.RWMutex
+	factories map[uint16]KEMFactory
+}
+
+// NewRegistry creates a new empty Registry.
+func NewRegistry() Registry {
+	return &registry{
+		factories: make(map[uint16]KEMFactory),
+	}
+}
+
+// Register adds a KEMFactory for the given schemeID.
+// Returns ErrDuplicateScheme if the schemeID is already registered.
+func (r *registry) Register(schemeID uint16, factory KEMFactory) error {
+	r.mutex.Lock()
+	defer r.mutex.Unlock()
+
+	if _, exists := r.factories[schemeID]; exists {
+		return fmt.Errorf(
+			"scheme 0x%04x: %w",
+			schemeID,
+			ErrDuplicateScheme,
+		)
+	}
+
+	r.factories[schemeID] = factory
+	return nil
+}
+
+// Lookup retrieves the KEMFactory for the given schemeID.
+// Returns ErrUnknownScheme if the schemeID is not registered.
+func (r *registry) Lookup(
+	schemeID uint16,
+) (
+	KEMFactory,
+	error,
+) {
+	r.mutex.RLock()
+	defer r.mutex.RUnlock()
+
+	factory, exists := r.factories[schemeID]
+	if !exists {
+		return nil, fmt.Errorf(
+			"scheme 0x%04x: %w",
+			schemeID,
+			ErrUnknownScheme,
+		)
+	}
+
+	return factory, nil
+}