init commit

registry.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"sort"
+	"time"
+)
+
+// Client is one entry in the JSON registry. The field tags reproduce the exact
+// object shape the bash/jq version wrote, so registries are interchangeable.
+type Client struct {
+	ID         int64  `json:"id"`
+	Name       string `json:"name"`
+	IP         string `json:"ip"`
+	PublicKey  string `json:"public_key"`
+	PrivateKey string `json:"private_key"`
+	PSKKey     string `json:"psk_key"`
+	IsEnabled  string `json:"is_enabled"`
+	CreatedAt  int64  `json:"created_at"`
+	// Comment is a free-form note attached to the profile via the web UI. It is
+	// registry-only (never written into the .conf) and omitted when empty so
+	// registries stay byte-compatible with the bash/jq version until a note is set.
+	Comment string `json:"comment,omitempty"`
+}
+
+// initStorage creates the data/client directories and an empty registry,
+// validating any existing registry JSON (bash: jq empty). Both directories
+// hold secret material (the registry's private_key field, client .conf/.png
+// files) so they are created owner-only.
+func initStorage() {
+	if err := os.MkdirAll(dataDir, 0700); err != nil {
+		die("Failed to create data dir: %v", err)
+	}
+	if err := os.MkdirAll(clientDir, 0700); err != nil {
+		die("Failed to create client dir: %v", err)
+	}
+	if _, err := os.Stat(registryFile); os.IsNotExist(err) {
+		if err := os.WriteFile(registryFile, []byte("[]"), 0644); err != nil {
+			die("Failed to initialise registry: %v", err)
+		}
+	}
+	// Validate JSON (equivalent to `jq empty`).
+	loadRegistry()
+}
+
+// loadRegistry reads and parses the registry, aborting on invalid JSON.
+func loadRegistry() []Client {
+	data, err := os.ReadFile(registryFile)
+	if err != nil {
+		die("Failed to read registry: %v", err)
+	}
+	var clients []Client
+	if err := json.Unmarshal(data, &clients); err != nil {
+		die("Registry JSON is invalid")
+	}
+	return clients
+}
+
+// saveRegistry writes the registry atomically (temp file + rename), matching
+// the bash mktemp/mv pattern, then re-validates it.
+func saveRegistry(clients []Client) {
+	data, err := json.MarshalIndent(clients, "", "  ")
+	if err != nil {
+		die("Failed to update registry: %v", err)
+	}
+	tmp, err := os.CreateTemp(dataDir, "registry-*.tmp")
+	if err != nil {
+		die("Failed to update registry: %v", err)
+	}
+	tmpName := tmp.Name()
+	if _, err := tmp.Write(data); err != nil {
+		tmp.Close()
+		os.Remove(tmpName)
+		die("Failed to update registry: %v", err)
+	}
+	tmp.Close()
+	if err := os.Rename(tmpName, registryFile); err != nil {
+		os.Remove(tmpName)
+		die("Failed to update registry: %v", err)
+	}
+	// Re-validate (bash: jq empty after write).
+	loadRegistry()
+}
+
+// getNextID returns max(id)+1, or 1 for an empty registry.
+func getNextID(clients []Client) int64 {
+	if len(clients) == 0 {
+		return 1
+	}
+	var max int64
+	for _, c := range clients {
+		if c.ID > max {
+			max = c.ID
+		}
+	}
+	return max + 1
+}
+
+// getLastIP returns the IP of the highest-id client (empty registry → "").
+func getLastIP(clients []Client) string {
+	if len(clients) == 0 {
+		return ""
+	}
+	sorted := append([]Client(nil), clients...)
+	sort.Slice(sorted, func(i, j int) bool { return sorted[i].ID < sorted[j].ID })
+	return sorted[len(sorted)-1].IP
+}
+
+// findClient returns a pointer to the client with the given id, or nil.
+func findClient(clients []Client, id int64) *Client {
+	for i := range clients {
+		if clients[i].ID == id {
+			return &clients[i]
+		}
+	}
+	return nil
+}
+
+// nowUnix returns the current Unix timestamp (bash: now|floor).
+func nowUnix() int64 {
+	return time.Now().Unix()
+}