diff --git a/keygen/keygen.c b/keygen/keygen.c
index c3dd99fd..58f7caad 100755
--- a/keygen/keygen.c
+++ b/keygen/keygen.c
@@ -53,6 +53,8 @@ key_gen(void)
   char* e_data;
   char* n_data;
   char* d_data;
+  unsigned char* p;
+  int len;
   int e_len;
   int n_len;
   int d_len;
@@ -64,10 +66,11 @@ key_gen(void)
   e_data = 0;
   n_data = 0;
   d_data = 0;
-  error = 0;
   my_ctx = BN_CTX_new();
   my_e = BN_new();
-  BN_bin2bn((unsigned char*)g_rev_exponent, sizeof(g_rev_exponent), my_e);
+  p = (unsigned char*)g_rev_exponent;
+  len = sizeof(g_rev_exponent);
+  BN_bin2bn(p, len, my_e);
   my_key = RSA_new();
   g_writeln("");
   g_writeln("Generating %d bit rsa key...", MY_KEY_SIZE);
@@ -82,7 +85,8 @@ key_gen(void)
     if (e_len > 0)
     {
       e_data = (char*)g_malloc(e_len, 0);
-      BN_bn2bin(my_key->e, (unsigned char*)e_data);
+      p = (unsigned char*)e_data;
+      BN_bn2bin(my_key->e, p);
       g_writeln("public exponent size %d bytes", e_len);
       g_hexdump(e_data, e_len);
       g_writeln("");
@@ -91,7 +95,8 @@ key_gen(void)
     if (n_len > 0)
     {
       n_data = (char*)g_malloc(n_len, 0);
-      BN_bn2bin(my_key->n, (unsigned char*)n_data);
+      p = (unsigned char*)n_data;
+      BN_bn2bin(my_key->n, p);
       g_writeln("public modulus size %d bytes", n_len);
       g_hexdump(n_data, n_len);
       g_writeln("");
@@ -100,7 +105,8 @@ key_gen(void)
     if (d_len > 0)
     {
       d_data = (char*)g_malloc(d_len, 0);
-      BN_bn2bin(my_key->d, (unsigned char*)d_data);
+      p = (unsigned char*)d_data;
+      BN_bn2bin(my_key->d, p);
       g_writeln("private exponent size %d bytes", d_len);
       g_hexdump(d_data, d_len);
       g_writeln("");