--- ../../sqmail-4.3.17/src/qmail-dkim.cpp	Thu Aug 29 10:49:00 2024
+++ ./qmail-dkim.cpp	Wed Dec 18 13:52:17 2024
@@ -266,7 +266,8 @@
 
     n = DKIMSignGetSig2(&ctxt,RSAPrivKey,ECCPrivKey,&pSig);
 
-    strcpy(szSignature,pSig);
+    if (n == DKIM_SUCCESS) 
+      strcpy(szSignature,pSig);
 
     DKIMSignFree(&ctxt);
 
@@ -277,8 +278,10 @@
     fprintf(FDLOG," outfile written %s \n",OutFile);
 #endif
 
-    fwrite(szSignature,1,strlen(szSignature),out);
-    fwrite("\r\n",1,2,out);
+    if (n == DKIM_SUCCESS) {
+      fwrite(szSignature,1,strlen(szSignature),out);
+      fwrite("\r\n",1,2,out);
+    }
 
     while (1) {
       BufLen = fread(Buffer,1,sizeof(Buffer),in);