diff --git a/src/common/crypto.c b/src/common/crypto.c
index 626e2c48e3f5dd2d0d390368db15e4e42bfd312c..177ae7949937558a48a1d9c047f6a10253c941cc 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -599,8 +599,8 @@ int crypto_cipher_encrypt_init_cipher(crypto_cipher_env_t *env)
   
   if (crypto_cipher_evp_cipher(env->type, 1)) {
     RETURN_SSL_OUTCOME(EVP_EncryptInit((EVP_CIPHER_CTX *)env->aux,
-				       crypto_cipher_evp_cipher(env->type, 1),
-				       env->key, env->iv));
+                                       crypto_cipher_evp_cipher(env->type, 1),
+                                       env->key, env->iv));
   } else {
     return -1;
   }
@@ -612,8 +612,8 @@ int crypto_cipher_decrypt_init_cipher(crypto_cipher_env_t *env)
 
   if (crypto_cipher_evp_cipher(env->type, 0)) {
     RETURN_SSL_OUTCOME(EVP_EncryptInit((EVP_CIPHER_CTX *)env->aux,
-				       crypto_cipher_evp_cipher(env->type, 0),
-				       env->key, env->iv));
+                                       crypto_cipher_evp_cipher(env->type, 0),
+                                       env->key, env->iv));
   } else {
     return -1;
   }
diff --git a/src/common/util.c b/src/common/util.c
index c448fbe89477542ad0061f953468ed0a69bf2c73..743df0bbb1601161aa444ebfc1c9a501025c30ed 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -3,6 +3,7 @@
 /* $Id$ */
 
 #include <stdlib.h>
+#include <limits.h>
 #include "util.h"
 #include "log.h"
 
@@ -21,6 +22,7 @@ my_gettimeofday(struct timeval *timeval)
 long
 tv_udiff(struct timeval *start, struct timeval *end)
 {
+  long udiff;
   long secdiff = end->tv_sec - start->tv_sec;
   if (secdiff+1 > LONG_MAX/1000000) {
     log(LOG_NOTICE, "tv_udiff(): comparing times too far apart.");
@@ -30,7 +32,12 @@ tv_udiff(struct timeval *start, struct timeval *end)
     end->tv_sec--;
     end->tv_usec += 1000000L;
   }
-  return secdiff*1000000L + (end->tv_usec - start->tv_usec);
+  udiff = secdiff*1000000L + (end->tv_usec - start->tv_usec);
+  if(udiff < 0) {
+    log(LOG_NOTICE, "tv_udiff(): start is after end. Returning 0.");
+    return 0;
+  }
+  return udiff;
 }
 
 int tv_cmp(struct timeval *a, struct timeval *b) {