keypair err mgt + shorturl random improve

server/identity.go

@@ -16,7 +16,7 @@ const key = "3pw0c8#6ZG8{75b5;3?fe80$2"
 type Identity struct {
 	ServerName     string               `json:"servername,omitempty"`
 	ServerDesc     string               `json:"serverdesc,omitempty"`
-	ServerKp       meowlib.KeyPair      `json:"server_kp,omitempty"`
+	ServerKp       *meowlib.KeyPair     `json:"server_kp,omitempty"`
 	Status         string               `json:"status,omitempty"`
 	OwnerName      string               `json:"owner_name,omitempty"`
 	OwnerPublicKey string               `json:"owner_public_key,omitempty"`
@@ -27,9 +27,13 @@ type Identity struct {
 
 func CreateIdentity(ServerName string, ServerDesc string) *Identity {
 	var id Identity
+	var err error
 	id.ServerName = ServerName
 	id.ServerDesc = ServerDesc
-	id.ServerKp = meowlib.NewKeyPair()
+	id.ServerKp, err = meowlib.NewKeyPair()
+	if err != nil {
+		return nil
+	}
 	return &id
 }
 

server/invitation.go

@@ -1,15 +1,21 @@
 package server
 
 import (
+	"crypto/rand"
 	"errors"
-	"math/rand"
+	"fmt"
+	"math/big"
+	"strings"
 	"time"
 
 	"github.com/go-redis/redis"
 )
 
-func (r *RedisRouter) StoreInvitation(invitation []byte, timeout int, password string, serverTimeout int, urlLen int) (string, time.Time) {
-	id := r.createShortId(urlLen)
+func (r *RedisRouter) StoreInvitation(invitation []byte, timeout int, password string, serverTimeout int, urlLen int) (string, time.Time, error) {
+	id, err := r.createShortId(urlLen)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("failed to create invitation ID: %w", err)
+	}
 	if timeout > serverTimeout {
 		timeout = serverTimeout
 	}
@@ -17,7 +23,7 @@ func (r *RedisRouter) StoreInvitation(invitation []byte, timeout int, password s
 	if len(password) > 0 {
 		r.Client.Set("mwpw:"+id, password, 0) //, time.Duration(timeout*1000000))
 	}
-	return id, time.Now().Add(time.Duration(timeout * 1000000)).UTC()
+	return id, time.Now().Add(time.Duration(timeout * 1000000)).UTC(), nil
 }
 
 func (r *RedisRouter) GetInvitation(id string, password string) ([]byte, error) {
@@ -54,17 +60,26 @@ func (r *RedisRouter) GetAnswerToInvitation(id string) ([]byte, error) {
 	return []byte(mwan), nil
 }
 
-func (r *RedisRouter) createShortId(length int) string {
-	id := ""
+func (r *RedisRouter) createShortId(length int) (string, error) {
 	alphabet := "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	alphabetLen := big.NewInt(int64(len(alphabet)))
+
 	// for not in redis
 	for {
-		for i := 1; i <= length; i++ {
-			id += string(alphabet[rand.Intn(61)])
+		var id strings.Builder
+		id.Grow(length)
+
+		for i := 0; i < length; i++ {
+			n, err := rand.Int(rand.Reader, alphabetLen)
+			if err != nil {
+				return "", fmt.Errorf("random generation failed: %w", err)
+			}
+			id.WriteByte(alphabet[n.Int64()])
 		}
-		if r.Client.Get("mwiv:"+id).Err() == redis.Nil {
-			break
+
+		idStr := id.String()
+		if r.Client.Get("mwiv:"+idStr).Err() == redis.Nil {
+			return idStr, nil
 		}
 	}
-	return id
 }

server/router.go

@@ -272,7 +272,10 @@ func (r *RedisRouter) handleInvitation(msg *meowlib.ToServerMessage) (*meowlib.F
 	switch msg.Invitation.Step {
 	// create invitation => provide shortcode and expiry
 	case 1:
-		url, expiry := r.StoreInvitation(msg.Invitation.Payload, int(msg.Invitation.Timeout), msg.Invitation.Password, r.InvitationTimeout, int(msg.Invitation.ShortcodeLen))
+		url, expiry, err := r.StoreInvitation(msg.Invitation.Payload, int(msg.Invitation.Timeout), msg.Invitation.Password, r.InvitationTimeout, int(msg.Invitation.ShortcodeLen))
+		if err != nil {
+			return nil, err
+		}
 		from_server.Invitation = &meowlib.Invitation{}
 		from_server.Invitation.Shortcode = url
 		from_server.Invitation.Expiry = expiry.UTC().Unix()