diff --git a/rsa.c b/rsa.c
index 42ca2fa..a1cb0b5 100644
--- a/rsa.c
+++ b/rsa.c
@@ -46,6 +46,7 @@ long long ExtEuclid(long long a, long long b)
 long long rsa_modExp(long long b, long long e, long long m)
 {
   if (b < 0 || e < 0 || m <= 0){
+    printf("%s: Invalid parameter(s)!\n", __FUNCTION__);
     exit(1);
   }
   b = b % m;
@@ -57,12 +58,13 @@ long long rsa_modExp(long long b, long long e, long long m)
   if( e % 2 == 1){
     return ( b * rsa_modExp(b, (e-1), m) % m );
   }
-
+  printf("%s: Impossible!\n", __FUNCTION__);
+  exit(1);
 }
 
 // Calling this function will generate a public and private key and store them in the pointers
 // it is given. 
-void rsa_gen_keys(struct public_key_class *pub, struct private_key_class *priv, char *PRIME_SOURCE_FILE)
+void rsa_gen_keys(struct public_key_class *pub, struct private_key_class *priv, const char *PRIME_SOURCE_FILE)
 {
   FILE *primes_list;
   if(!(primes_list = fopen(PRIME_SOURCE_FILE, "r"))){
@@ -126,6 +128,9 @@ void rsa_gen_keys(struct public_key_class *pub, struct private_key_class *priv,
     phi_max = (p-1)*(q-1);
   }
   while(!(p && q) || (p == q) || (gcd(phi_max, e) != 1));
+
+  fclose(primes_list);
+  primes_list = NULL;
  
   // Next, we need to choose a,b, so that a*max+b*e = gcd(max,e). We actually only need b
   // here, and in keeping with the usual notation of RSA we'll call it d. We'd also like 
diff --git a/rsa.h b/rsa.h
index f0208f3..77a8a7f 100644
--- a/rsa.h
+++ b/rsa.h
@@ -28,12 +28,12 @@ void rsa_gen_keys(struct public_key_class *pub, struct private_key_class *priv,
 // This function will encrypt the data pointed to by message. It returns a pointer to a heap
 // array containing the encrypted data, or NULL upon failure. This pointer should be freed when 
 // you are finished. The encrypted data will be 8 times as large as the original data.
-long long *rsa_encrypt(const char *message, const unsigned long message_size, const struct public_key_class *pub);
+long long *rsa_encrypt(const char *message, unsigned long message_size, const struct public_key_class *pub);
 
 // This function will decrypt the data pointed to by message. It returns a pointer to a heap
 // array containing the decrypted data, or NULL upon failure. This pointer should be freed when 
 // you are finished. The variable message_size is the size in bytes of the encrypted message. 
 // The decrypted data will be 1/8th the size of the encrypted data.
-char *rsa_decrypt(const long long *message, const unsigned long message_size, const struct private_key_class *pub);
+char *rsa_decrypt(const long long *message, unsigned long message_size, const struct private_key_class *pub);
 
 #endif
diff --git a/test.c b/test.c
index 95c6c9f..5b0a56b 100644
--- a/test.c
+++ b/test.c
@@ -40,7 +40,7 @@ int main(int argc, char **argv)
     printf("%lld\n", (long long)decrypted[i]);
   }  
   
-  printf("\n");
+  printf("\nDone\n");
   free(encrypted);
   free(decrypted);
   return 0;