Add export and import for profiles

profile/icons.go

@@ -0,0 +1,69 @@
+package profile
+
+import (
+	"crypto"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/safing/portbase/api"
+)
+
+var profileIconStoragePath = ""
+
+// GetProfileIcon returns the profile icon with the given ID and extension.
+func GetProfileIcon(id, ext string) (data []byte, err error) {
+	// Build storage path.
+	iconPath := filepath.Join(profileIconStoragePath, id+"."+ext)
+	iconPath, err = filepath.Abs(iconPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to check icon path: %w", err)
+	}
+	// Do a quick check if we are still within the right directory.
+	// This check is not entirely correct, but is sufficient for this use case.
+	if !strings.HasPrefix(iconPath, profileIconStoragePath) {
+		return nil, api.ErrorWithStatus(errors.New("invalid icon"), http.StatusBadRequest)
+	}
+
+	return os.ReadFile(iconPath)
+}
+
+// UpdateProfileIcon creates or updates the given icon.
+func UpdateProfileIcon(data []byte, ext string) (filename string, err error) {
+	// Check icon size.
+	if len(data) > 1_000_000 {
+		return "", errors.New("icon too big")
+	}
+
+	// Calculate sha1 sum of icon.
+	h := crypto.SHA1.New()
+	if _, err := h.Write(data); err != nil {
+		return "", err
+	}
+	sum := hex.EncodeToString(h.Sum(nil))
+
+	// Check ext.
+	ext = strings.ToLower(ext)
+	switch ext {
+	case "gif":
+	case "jpeg":
+		ext = "jpg"
+	case "jpg":
+	case "png":
+	case "svg":
+	case "tiff":
+	case "webp":
+	default:
+		return "", errors.New("unsupported icon format")
+	}
+
+	// Save to disk.
+	filename = sum + "." + ext
+	return filename, os.WriteFile(filepath.Join(profileIconStoragePath, filename), data, 0o0644) //nolint:gosec
+}
+
+// TODO: Clean up icons regularly.