From 6a5c6c55096ea8ac99587accc3120b72d9dcfe23 Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Thu, 15 Dec 2022 16:28:10 +0100
Subject: [PATCH] Improve ElGamal validation by refraining from biginteger for
 loop variable

---
 .../key/util/PublicKeyParameterValidationUtil.java       | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/util/PublicKeyParameterValidationUtil.java b/pgpainless-core/src/main/java/org/pgpainless/key/util/PublicKeyParameterValidationUtil.java
index 88e9897a..344f063b 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/util/PublicKeyParameterValidationUtil.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/util/PublicKeyParameterValidationUtil.java
@@ -265,14 +265,15 @@ public class PublicKeyParameterValidationUtil {
 
         // check g^i mod p != 1 for i < threshold
         BigInteger res = g;
-        BigInteger i = BigInteger.valueOf(1);
-        BigInteger threshold = BigInteger.valueOf(2).shiftLeft(17);
-        while (i.compareTo(threshold) < 0) {
+        // 262144
+        int threshold = 2 << 17;
+        int i = 1;
+        while (i < threshold) {
             res = res.multiply(g).mod(p);
             if (res.equals(one)) {
                 return false;
             }
-            i = i.add(one);
+            i++;
         }
 
         // blinded exponentiation to check y = g^(r*(p-1)+x) mod p