feat: establish secure update foundation

internal/appupdate/version.go

@@ -1,66 +1,15 @@
 package appupdate
 
-import (
-	"fmt"
-	"strconv"
-	"strings"
-
-	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/updateprotocol"
-)
-
-type semanticVersion struct {
-	major int
-	minor int
-	patch int
-}
-
-func parseVersion(raw string) (semanticVersion, error) {
-	if !strings.HasPrefix(raw, "v") || strings.ContainsAny(raw, "+-") {
-		return semanticVersion{}, fmt.Errorf("version must use vMAJOR.MINOR.PATCH")
-	}
-	parts := strings.Split(strings.TrimPrefix(raw, "v"), ".")
-	if len(parts) != 3 {
-		return semanticVersion{}, fmt.Errorf("version must use vMAJOR.MINOR.PATCH")
-	}
-	values := make([]int, 3)
-	for index, part := range parts {
-		if part == "" || (len(part) > 1 && part[0] == '0') {
-			return semanticVersion{}, fmt.Errorf("version contains an invalid number")
-		}
-		value, err := strconv.Atoi(part)
-		if err != nil || value < 0 || value > 1_000_000 {
-			return semanticVersion{}, fmt.Errorf("version contains an invalid number")
-		}
-		values[index] = value
-	}
-	return semanticVersion{major: values[0], minor: values[1], patch: values[2]}, nil
-}
+import "github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/updateprotocol"
 
 func compareVersions(left, right string) (int, error) {
-	a, err := parseVersion(left)
-	if err != nil {
-		return 0, err
-	}
-	b, err := parseVersion(right)
-	if err != nil {
-		return 0, err
-	}
-	av, bv := []int{a.major, a.minor, a.patch}, []int{b.major, b.minor, b.patch}
-	for index := range av {
-		if av[index] < bv[index] {
-			return -1, nil
-		}
-		if av[index] > bv[index] {
-			return 1, nil
-		}
-	}
-	return 0, nil
+	return updateprotocol.CompareVersions(left, right)
 }
 
 func validReleaseVersion(version string) bool {
 	if !updateprotocol.ValidVersion(version) {
 		return false
 	}
-	_, err := parseVersion(version)
+	_, err := updateprotocol.CompareVersions(version, version)
 	return err == nil
 }