Merge pull request #2625 from dhalbert/to_bytes-signed

Implement to_bytes(..., signed=True)
crypto-aes
Scott Shawcroft 3 years ago committed by GitHub
commit 850e655a4c
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GPG Key ID: 4AEE18F83AFDEB23
  1. 37
      py/objint.c
  2. 12
      tests/basics/int_bytes.py
  3. 8
      tests/basics/int_bytes_intbig.py
  4. 1
      tests/basics/int_longint_bytes.py

@ -490,15 +490,24 @@ STATIC mp_obj_t int_from_bytes(size_t n_args, const mp_obj_t *args) {
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(int_from_bytes_fun_obj, 3, 4, int_from_bytes);
STATIC MP_DEFINE_CONST_CLASSMETHOD_OBJ(int_from_bytes_obj, MP_ROM_PTR(&int_from_bytes_fun_obj));
STATIC mp_obj_t int_to_bytes(size_t n_args, const mp_obj_t *args) {
// TODO: Support signed param (assumes signed=False)
(void)n_args;
mp_int_t len = mp_obj_get_int(args[1]);
STATIC mp_obj_t int_to_bytes(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_length, ARG_byteorder, ARG_signed };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_length, MP_ARG_REQUIRED | MP_ARG_INT },
{ MP_QSTR_byteorder, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_signed, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_int_t len = args[ARG_length].u_int;
if (len < 0) {
mp_raise_ValueError(NULL);
}
bool big_endian = args[2] != MP_OBJ_NEW_QSTR(MP_QSTR_little);
mp_obj_t self = pos_args[0];
bool big_endian = args[ARG_byteorder].u_obj != MP_OBJ_NEW_QSTR(MP_QSTR_little);
bool signed_ = args[ARG_signed].u_bool;
vstr_t vstr;
vstr_init_len(&vstr, len);
@ -506,22 +515,26 @@ STATIC mp_obj_t int_to_bytes(size_t n_args, const mp_obj_t *args) {
memset(data, 0, len);
#if MICROPY_LONGINT_IMPL != MICROPY_LONGINT_IMPL_NONE
if (!MP_OBJ_IS_SMALL_INT(args[0])) {
mp_obj_int_buffer_overflow_check(args[0], len, false);
mp_obj_int_to_bytes_impl(args[0], big_endian, len, data);
if (!MP_OBJ_IS_SMALL_INT(self)) {
mp_obj_int_buffer_overflow_check(self, len, signed_);
mp_obj_int_to_bytes_impl(self, big_endian, len, data);
} else
#endif
{
mp_int_t val = MP_OBJ_SMALL_INT_VALUE(args[0]);
mp_int_t val = MP_OBJ_SMALL_INT_VALUE(self);
// Small int checking is separate, to be fast.
mp_small_int_buffer_overflow_check(val, len, false);
mp_small_int_buffer_overflow_check(val, len, signed_);
size_t l = MIN((size_t)len, sizeof(val));
if (val < 0) {
// Sign extend negative numbers.
memset(data, -1, len);
}
mp_binary_set_int(l, big_endian, data + (big_endian ? (len - l) : 0), val);
}
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(int_to_bytes_obj, 3, 4, int_to_bytes);
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(int_to_bytes_obj, 3, int_to_bytes);
STATIC const mp_rom_map_elem_t int_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_from_bytes), MP_ROM_PTR(&int_from_bytes_obj) },

@ -1,8 +1,11 @@
print((10).to_bytes(1, "little"))
print((-10).to_bytes(1, "little", signed=True))
# Test fitting in length that's not a power of two.
print((0x10000).to_bytes(3, 'little'))
print((111111).to_bytes(4, "little"))
print((-111111).to_bytes(4, "little", signed=True))
print((100).to_bytes(10, "little"))
print((-100).to_bytes(10, "little", signed=True))
# check that extra zero bytes don't change the internal int value
print(int.from_bytes(bytes(20), "little") == 0)
@ -10,7 +13,9 @@ print(int.from_bytes(b"\x01" + bytes(20), "little") == 1)
# big-endian conversion
print((10).to_bytes(1, "big"))
print((-10).to_bytes(1, "big", signed=True))
print((100).to_bytes(10, "big"))
print((-100).to_bytes(10, "big", signed=True))
print(int.from_bytes(b"\0\0\0\0\0\0\0\0\0\x01", "big"))
print(int.from_bytes(b"\x01\0", "big"))
@ -26,8 +31,13 @@ try:
except OverflowError:
print("OverflowError")
# negative numbers should raise an error
# negative numbers should raise an error if signed=False
try:
(-256).to_bytes(2, "little")
except OverflowError:
print("OverflowError")
try:
(-256).to_bytes(2, "little", signed=False)
except OverflowError:
print("OverflowError")

@ -2,7 +2,9 @@ import skip_if
skip_if.no_bigint()
print((2**64).to_bytes(9, "little"))
print((-2**64).to_bytes(9, "little", signed=True))
print((2**64).to_bytes(9, "big"))
print((-2**64).to_bytes(9, "big", signed=True))
b = bytes(range(20))
@ -22,8 +24,12 @@ try:
except OverflowError:
print("OverflowError")
# negative numbers should raise an error
# negative numbers should raise an error if signed=False
try:
(-2**64).to_bytes(9, "little")
except OverflowError:
print("OverflowError")
try:
(-2**64).to_bytes(9, "little", signed=False)
except OverflowError:
print("OverflowError")

@ -3,6 +3,7 @@ import skip_if
skip_if.no_bigint()
print((2**64).to_bytes(9, "little"))
print((-2**64).to_bytes(9, "little", signed=True))
print(int.from_bytes(b"\x00\x01\0\0\0\0\0\0", "little"))
print(int.from_bytes(b"\x01\0\0\0\0\0\0\0", "little"))
print(int.from_bytes(b"\x00\x01\0\0\0\0\0\0", "little"))

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