From 3e8b025cbdaf52d04da4d542136e3a7dc061b474 Mon Sep 17 00:00:00 2001
From: Pavol Rusnak <stick@gk2.sk>
Date: Fri, 7 Oct 2016 13:57:21 +0200
Subject: [PATCH] use mp_obj_new_str_of_type where it makes sense instead of
 mp_obj_new_str_from_vstr

---
 extmod/modtrezorcrypto/modtrezorcrypto-bip39.h  | 10 ++--------
 extmod/modtrezorcrypto/modtrezorcrypto-random.h |  3 +++
 extmod/modtrezormsg/modtrezormsg.c              |  6 ++----
 src/tests/test_crypto_random.py                 |  4 ++++
 4 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/extmod/modtrezorcrypto/modtrezorcrypto-bip39.h b/extmod/modtrezorcrypto/modtrezorcrypto-bip39.h
index 52fbda9028..66a7340ad5 100644
--- a/extmod/modtrezorcrypto/modtrezorcrypto-bip39.h
+++ b/extmod/modtrezorcrypto/modtrezorcrypto-bip39.h
@@ -30,10 +30,7 @@ STATIC mp_obj_t mod_TrezorCrypto_Bip39_generate(mp_obj_t self, mp_obj_t strength
         mp_raise_ValueError("Invalid bit strength (only 128, 160, 192, 224 and 256 values are allowed)");
     }
     const char *mnemo = mnemonic_generate(bits);
-    vstr_t vstr;
-    vstr_init_len(&vstr, strlen(mnemo));
-    strcpy(vstr.buf, mnemo);
-    return mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
+    return mp_obj_new_str_of_type(&mp_type_str, (uint8_t *)mnemo, strlen(mnemo));
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_TrezorCrypto_Bip39_generate_obj, mod_TrezorCrypto_Bip39_generate);
 
@@ -48,10 +45,7 @@ STATIC mp_obj_t mod_TrezorCrypto_Bip39_from_data(mp_obj_t self, mp_obj_t data) {
         mp_raise_ValueError("Invalid data length (only 16, 20, 24, 28 and 32 bytes are allowed)");
     }
     const char *mnemo = mnemonic_from_data(bin.buf, bin.len);
-    vstr_t vstr;
-    vstr_init_len(&vstr, strlen(mnemo));
-    strcpy(vstr.buf, mnemo);
-    return mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
+    return mp_obj_new_str_of_type(&mp_type_str, (uint8_t *)mnemo, strlen(mnemo));
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_TrezorCrypto_Bip39_from_data_obj, mod_TrezorCrypto_Bip39_from_data);
 
diff --git a/extmod/modtrezorcrypto/modtrezorcrypto-random.h b/extmod/modtrezorcrypto/modtrezorcrypto-random.h
index 6892c8eb44..bde50872fa 100644
--- a/extmod/modtrezorcrypto/modtrezorcrypto-random.h
+++ b/extmod/modtrezorcrypto/modtrezorcrypto-random.h
@@ -39,6 +39,9 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_TrezorCrypto_Random_uniform_obj, mod_Trezor
 ///     '''
 STATIC mp_obj_t mod_TrezorCrypto_Random_bytes(mp_obj_t self, mp_obj_t len) {
     uint32_t l = mp_obj_get_int(len);
+    if (l > 8192) {
+        mp_raise_ValueError("Maximum requested size is 8192");
+    }
     vstr_t vstr;
     vstr_init_len(&vstr, l);
     random_buffer((uint8_t *)vstr.buf, l);
diff --git a/extmod/modtrezormsg/modtrezormsg.c b/extmod/modtrezormsg/modtrezormsg.c
index dc71a28f57..71a277336d 100644
--- a/extmod/modtrezormsg/modtrezormsg.c
+++ b/extmod/modtrezormsg/modtrezormsg.c
@@ -13,6 +13,7 @@
 #include "py/runtime.h"
 #include "py/binary.h"
 #include "py/mphal.h"
+#include "py/objstr.h"
 
 #if MICROPY_PY_TREZORMSG
 
@@ -107,12 +108,9 @@ STATIC mp_obj_t mod_TrezorMsg_Msg_select(mp_obj_t self, mp_obj_t timeout_us) {
         uint8_t recvbuf[64];
         ssize_t l = msg_recv(&iface, recvbuf, 64);
         if (l > 0) {
-            vstr_t vstr;
-            vstr_init_len(&vstr, l);
-            memcpy(vstr.buf, recvbuf, l);
             mp_obj_tuple_t *tuple = MP_OBJ_TO_PTR(mp_obj_new_tuple(2, NULL));
             tuple->items[0] = MP_OBJ_NEW_SMALL_INT(iface);
-            tuple->items[1] = mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
+            tuple->items[1] = mp_obj_new_str_of_type(&mp_type_bytes, recvbuf, l);
             return MP_OBJ_FROM_PTR(tuple);
          }
         if (timeout <= 0) {
diff --git a/src/tests/test_crypto_random.py b/src/tests/test_crypto_random.py
index ecb3f95760..d4d2577b77 100644
--- a/src/tests/test_crypto_random.py
+++ b/src/tests/test_crypto_random.py
@@ -23,6 +23,10 @@ class TestCryptoRandom(unittest.TestCase):
             lst = random.bytes(l)
             self.assertEqual(len(lst), l)
 
+    def test_bytes_big_length(self):
+        with self.assertRaises(ValueError):
+            random.bytes(10000)
+
     def test_bytes_uniform(self):
         for _ in range(100):
             b = random.bytes(8000)