feat(passkeys): name new passkeys based on agguids (#332)

Co-authored-by: Alessandro (Ale) Segala <43508+ItalyPaleAle@users.noreply.github.com>
Co-authored-by: Elias Schneider <login@eliasschneider.com>

backend/internal/utils/aaguid_util.go

@@ -0,0 +1,64 @@
+package utils
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"log"
+	"sync"
+
+	"github.com/pocket-id/pocket-id/backend/resources"
+)
+
+var (
+	aaguidMap     map[string]string
+	aaguidMapOnce sync.Once
+)
+
+// FormatAAGUID converts an AAGUID byte slice to UUID string format
+func FormatAAGUID(aaguid []byte) string {
+	if len(aaguid) == 0 {
+		return ""
+	}
+
+	// If exactly 16 bytes, format as UUID
+	if len(aaguid) == 16 {
+		return fmt.Sprintf("%x-%x-%x-%x-%x",
+			aaguid[0:4], aaguid[4:6], aaguid[6:8], aaguid[8:10], aaguid[10:16])
+	}
+
+	// Otherwise just return as hex
+	return hex.EncodeToString(aaguid)
+}
+
+// GetAuthenticatorName returns the name of the authenticator for the given AAGUID
+func GetAuthenticatorName(aaguid []byte) string {
+	aaguidStr := FormatAAGUID(aaguid)
+	if aaguidStr == "" {
+		return ""
+	}
+
+	// Then check JSON-sourced map
+	aaguidMapOnce.Do(loadAAGUIDsFromFile)
+
+	if name, ok := aaguidMap[aaguidStr]; ok {
+		return name + " Passkey"
+	}
+
+	return ""
+}
+
+// loadAAGUIDsFromFile loads AAGUID data from the embedded file system
+func loadAAGUIDsFromFile() {
+	// Read from embedded file system
+	data, err := resources.FS.ReadFile("aaguids.json")
+	if err != nil {
+		log.Printf("Error reading embedded AAGUID file: %v", err)
+		return
+	}
+
+	if err := json.Unmarshal(data, &aaguidMap); err != nil {
+		log.Printf("Error unmarshalling AAGUID data: %v", err)
+		return
+	}
+}