py/binary: Change internal bytearray typecode from 0 to 1.

The value of 0 can't be used because otherwise mp_binary_get_size will let
a null byte through as the type code (intepreted as byterray).  This can
lead to invalid type-specifier strings being let through without an error
in the struct module, and even buffer overruns.
crypto-aes
Damien George 6 years ago
parent e4ab404780
commit 025e5f2b33

@ -29,8 +29,9 @@
#include "py/obj.h"
// Use special typecode to differentiate repr() of bytearray vs array.array('B')
// (underlyingly they're same).
#define BYTEARRAY_TYPECODE 0
// (underlyingly they're same). Can't use 0 here because that's used to detect
// type-specification errors due to end-of-string.
#define BYTEARRAY_TYPECODE 1
size_t mp_binary_get_size(char struct_type, char val_type, mp_uint_t *palign);
mp_obj_t mp_binary_get_val_array(char typecode, void *p, mp_uint_t index);

@ -40,3 +40,30 @@ try:
struct.calcsize('0z')
except:
print('Exception')
# check that a count without a type specifier raises an exception
try:
struct.calcsize('1')
except:
print('Exception')
try:
struct.pack('1')
except:
print('Exception')
try:
struct.pack_into('1', bytearray(4), 0, 'xx')
except:
print('Exception')
try:
struct.unpack('1', 'xx')
except:
print('Exception')
try:
struct.unpack_from('1', 'xx')
except:
print('Exception')

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