From 8f8c0f27dfe7a45728a58c04f2e29c7a07cffeb5 Mon Sep 17 00:00:00 2001
From: CaiHQ <caihq@pku.edu.cn>
Date: Tue, 2 Nov 2021 17:45:08 +0800
Subject: [PATCH] fix BigInteger overflow

---
 src/main/java/org.zz/gmhelper/SM2Util.java | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org.zz/gmhelper/SM2Util.java b/src/main/java/org.zz/gmhelper/SM2Util.java
index e308d6c..77ba837 100644
--- a/src/main/java/org.zz/gmhelper/SM2Util.java
+++ b/src/main/java/org.zz/gmhelper/SM2Util.java
@@ -379,8 +379,8 @@ public class SM2Util extends GMBaseUtil {
         }
 
         ASN1Encodable[] arr = new ASN1Encodable[4];
-        arr[0] = new ASN1Integer(c1x);
-        arr[1] = new ASN1Integer(c1y);
+        arr[0] = new ASN1Integer(new BigInteger(1,c1x));
+        arr[1] = new ASN1Integer(new BigInteger(1,c1y));
         if (mode == Mode.C1C2C3) {
             arr[2] = new DEROctetString(c2);
             arr[3] = new DEROctetString(c3);
@@ -414,6 +414,8 @@ public class SM2Util extends GMBaseUtil {
         byte[] c1y = ((ASN1Integer) as.getObjectAt(1)).getValue().toByteArray();
         byte[] c3;
         byte[] c2;
+        c1x = fixToCurveLengthBytes(c1x);
+        c1y = fixToCurveLengthBytes(c1y);
         if (mode == Mode.C1C2C3) {
             c2 = ((DEROctetString) as.getObjectAt(2)).getOctets();
             c3 = ((DEROctetString) as.getObjectAt(3)).getOctets();