diff -up gnutls-3.1.11/lib/gnutls_ecc.c.suiteb gnutls-3.1.11/lib/gnutls_ecc.c
--- gnutls-3.1.11/lib/gnutls_ecc.c.suiteb	2013-04-27 10:04:48.000000000 +0200
+++ gnutls-3.1.11/lib/gnutls_ecc.c	2013-05-23 10:08:45.331883555 +0200
@@ -129,6 +129,12 @@ int ret;
       goto cleanup;
     }
   params->params_nr++;
+
+  if (_gnutls_mpi_get_nbits(params->params[ECC_PRIME]) < 256)
+    {
+      ret = gnutls_assert_val(GNUTLS_E_ECC_UNSUPPORTED_CURVE);
+      goto cleanup;
+    }
   
   val_size = sizeof(val);
   ret = _gnutls_hex2bin(st->order, strlen(st->order), val, &val_size);
diff -up gnutls-3.1.11/lib/nettle/ecc_mulmod_cached.c.suiteb gnutls-3.1.11/lib/nettle/ecc_mulmod_cached.c
--- gnutls-3.1.11/lib/nettle/ecc_mulmod_cached.c.suiteb	2013-04-27 10:04:48.000000000 +0200
+++ gnutls-3.1.11/lib/nettle/ecc_mulmod_cached.c	2013-05-23 10:24:56.575967312 +0200
@@ -42,6 +42,7 @@ typedef struct
 
 /* global cache */
 static gnutls_ecc_curve_cache_entry_t *ecc_wmnaf_cache = NULL;
+static gnutls_ecc_curve_cache_entry_t *ecc_wmnaf_cache_last = NULL;
 
 /* free single cache entry */
 static void
@@ -63,9 +64,10 @@ ecc_wmnaf_cache_free (void)
   gnutls_ecc_curve_cache_entry_t *p = ecc_wmnaf_cache;
   if (p)
     {
-      for (; p->id != GNUTLS_ECC_CURVE_INVALID; ++p)
+      for (; p <= ecc_wmnaf_cache_last; ++p)
         {
-          _ecc_wmnaf_cache_entry_free (p);
+          if (p->id != GNUTLS_ECC_CURVE_INVALID)
+            _ecc_wmnaf_cache_entry_free (p);
         }
 
       free (ecc_wmnaf_cache);
@@ -198,7 +200,7 @@ ecc_wmnaf_cache_init (void)
   const gnutls_ecc_curve_t *p;
 
   ret = (gnutls_ecc_curve_cache_entry_t *)
-    malloc (MAX_ALGOS * sizeof (gnutls_ecc_curve_cache_entry_t));
+    calloc (MAX_ALGOS, sizeof (gnutls_ecc_curve_cache_entry_t));
   if (ret == NULL)
     return GNUTLS_E_MEMORY_ERROR;
 
@@ -207,12 +209,16 @@ ecc_wmnaf_cache_init (void)
 
   for (j = 0; *p; ++p, ++j)
     {
-      if ((err = _ecc_wmnaf_cache_entry_init (ret + *p - 1, *p)) != 0)
+      gnutls_ecc_curve_cache_entry_t *entry;
+
+      entry = ret + *p - 1;
+      if ((err = _ecc_wmnaf_cache_entry_init (entry, *p)) != 0)
         goto done;
+      if (ecc_wmnaf_cache_last < entry)
+        ecc_wmnaf_cache_last = entry;
     }
 
-  /* nullify last cache entry id */
-  ret[j].id = GNUTLS_ECC_CURVE_INVALID;
+  /* no need to nullify last cache entry id, done by calloc */
 
   err = GNUTLS_E_SUCCESS;
 
@@ -223,7 +229,8 @@ done:
       int i;
       for (i = 0; i < j; ++i)
         {
-          _ecc_wmnaf_cache_entry_free (ret + i);
+          --p;
+          _ecc_wmnaf_cache_entry_free (ret + *p - 1);
         }
 
       free (ret);
@@ -445,9 +452,11 @@ ecc_mulmod_cached_lookup (mpz_t k, ecc_p
   if (k == NULL || G == NULL || R == NULL || modulus == NULL)
     return GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER;
 
-  for (i = 0; (id = ecc_wmnaf_cache[i].id); ++i)
+  for (i = 0; ecc_wmnaf_cache + i <= ecc_wmnaf_cache_last; ++i)
     {
-      if (!(mpz_cmp (G->x, ecc_wmnaf_cache[i].pos[0]->x)) &&
+      id = ecc_wmnaf_cache[i].id;
+      if (id &&
+          !(mpz_cmp (G->x, ecc_wmnaf_cache[i].pos[0]->x)) &&
           !(mpz_cmp (G->y, ecc_wmnaf_cache[i].pos[0]->y)))
         {
           break;
diff -up gnutls-3.1.11/tests/mini-xssl.c.suiteb gnutls-3.1.11/tests/mini-xssl.c
--- gnutls-3.1.11/tests/mini-xssl.c.suiteb	2013-05-10 10:10:27.000000000 +0200
+++ gnutls-3.1.11/tests/mini-xssl.c	2013-05-23 11:58:22.670298910 +0200
@@ -27,7 +27,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#if defined(_WIN32)
+/* uses unsupported curves */
+#if 1
 
 int main()
 {
diff -up gnutls-3.1.11/tests/pkcs12_simple.c.suiteb gnutls-3.1.11/tests/pkcs12_simple.c
--- gnutls-3.1.11/tests/pkcs12_simple.c.suiteb	2013-05-10 10:10:27.000000000 +0200
+++ gnutls-3.1.11/tests/pkcs12_simple.c	2013-05-23 11:57:59.776799848 +0200
@@ -50,6 +50,9 @@ doit (void)
   gnutls_x509_privkey_t pkey;
   int ret;
 
+  /* uses unsupported curves */
+  exit(77);
+
   ret = global_init ();
   if (ret < 0)
     fail ("global_init failed %d\n", ret);