def test_byte_length_correctness(self):
numbers = [-12, 12, 1200, 120091, 123456789]
for num in numbers:
if num < 0:
bit_length = len(bin(num, None)) - 1
else:
bit_length = len(bin(num, None))
count = int(math.ceil(bit_length / 8.0))
self.assertEqual(
builtins.integer_byte_length(num), count, "Boom. for number %d, expected %d" % (num, count)
)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(num), count)
self.assertEqual(_alt_builtins.integer_byte_length_word_aligned(num), count)
self.assertEqual(builtins.integer_byte_length(1 << 1023), 128)
self.assertEqual(builtins.integer_byte_length((1 << 1024) - 1), 128)
self.assertEqual(builtins.integer_byte_length(1 << 1024), 129)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(1 << 1023), 128)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting((1 << 1024) - 1), 128)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(1 << 1024), 129)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(1 << 1023), 128)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting((1 << 1024) - 1), 128)
self.assertEqual(_alt_builtins.integer_byte_length_word_aligned(1 << 1024), 129)
def long_to_mpi(num):
"""
Converts a long value into an OpenSSL-format MPI Bignum byte string.
:param num:
Long value.
:returns:
OpenSSL-format MPI Bignum byte string.
"""
# from mom._types.bytearray import \
# long_to_bytearray, bytearray_concat, \
# bytearray_to_bytes, bytearray_create_zeros
byte_array = long_to_bytearray(num)
ext = 0
# If the high-order bit is going to be set,
# add an extra byte of zeros
if not (builtins.integer_bit_length(num) & 0x7):
ext = 1
length = builtins.integer_byte_length(num) + ext
byte_array = bytearray_concat(bytearray_create_zeros(4 + ext), byte_array)
byte_array[0] = (length >> 24) & 0xFF
byte_array[1] = (length >> 16) & 0xFF
byte_array[2] = (length >> 8) & 0xFF
byte_array[3] = length & 0xFF
return bytearray_to_bytes(byte_array)
def long_to_mpi(num):
"""
Converts a long value into an OpenSSL-format MPI Bignum byte string.
:param num:
Long value.
:returns:
OpenSSL-format MPI Bignum byte string.
"""
# from mom._types.bytearray import \
# long_to_bytearray, bytearray_concat, \
# bytearray_to_bytes, bytearray_create_zeros
byte_array = long_to_bytearray(num)
ext = 0
# If the high-order bit is going to be set,
# add an extra byte of zeros
if not (builtins.integer_bit_length(num) & 0x7):
ext = 1
length = builtins.integer_byte_length(num) + ext
byte_array = bytearray_concat(bytearray_create_zeros(4 + ext), byte_array)
byte_array[0] = (length >> 24) & 0xFF
byte_array[1] = (length >> 16) & 0xFF
byte_array[2] = (length >> 8) & 0xFF
byte_array[3] = length & 0xFF
return bytearray_to_bytes(byte_array)
def test_byte_length_correctness(self):
numbers = [-12, 12, 1200, 120091, 123456789]
for num in numbers:
if num < 0:
bit_length = len(bin(num, None)) - 1
else:
bit_length = len(bin(num, None))
count = int(math.ceil(bit_length / 8.0))
self.assertEqual(builtins.integer_byte_length(num), count,
"Boom. for number %d, expected %d" % (num, count))
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(num), count)
self.assertEqual(_alt_builtins.integer_byte_length_word_aligned(num), count)
self.assertEqual(builtins.integer_byte_length(1 << 1023), 128)
self.assertEqual(builtins.integer_byte_length((1 << 1024) - 1), 128)
self.assertEqual(builtins.integer_byte_length(1 << 1024), 129)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(1 << 1023), 128)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting((1 << 1024) - 1), 128)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(1 << 1024), 129)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(1 << 1023), 128)
self.assertEqual(_alt_builtins.integer_byte_length_shift_counting((1 << 1024) - 1), 128)
self.assertEqual(_alt_builtins.integer_byte_length_word_aligned(1 << 1024), 129)
def long_to_bytearray(num):
"""
Converts a long into a byte array.
:param num:
Long value
:returns:
Long.
"""
bytes_count = builtins.integer_byte_length(num)
byte_array = bytearray_create_zeros(bytes_count)
for count in range(bytes_count - 1, -1, -1):
byte_array[count] = int(num % 256)
num >>= 8
return byte_array
def long_to_bytearray(num):
"""
Converts a long into a byte array.
:param num:
Long value
:returns:
Long.
"""
bytes_count = builtins.integer_byte_length(num)
byte_array = bytearray_create_zeros(bytes_count)
for count in range(bytes_count - 1, -1, -1):
byte_array[count] = int(num % 256)
num >>= 8
return byte_array
def uint_to_bytes_naive(number, block_size=0):
"""
Naive slow and accurate implementation. Base for all our tests.
Converts a number to a string of bytes.
:param number: the number to convert
:param block_size: the number of bytes to output. If the number encoded to
bytes is less than this, the block will be zero-padded. When not given,
the returned block is not padded.
:raises:
``OverflowError`` when block_size is given and the number takes up more
bytes than fit into the block.
"""
if number < 0:
raise ValueError("Negative numbers cannot be used: %d" % number)
# Do some bounds checking
needed_bytes = builtins.integer_byte_length(number)
if block_size > 0:
if needed_bytes > block_size:
raise OverflowError("Needed %i bytes for number, but block size "
"is %i" % (needed_bytes, block_size))
# Convert the number to bytes.
if number == 0:
raw_bytes = [ZERO_BYTE]
else:
raw_bytes = []
num = number
while num > 0:
raw_bytes.insert(0, builtins.byte(num & 0xFF))
num >>= 8
# Pad with zeroes to fill the block
if block_size > 0:
padding_size = (block_size - needed_bytes)
if number == 0:
padding_size -= 1
padding = ZERO_BYTE * padding_size
else:
padding = EMPTY_BYTE
return padding + EMPTY_BYTE.join(raw_bytes)
def uint_to_bytes_naive(number, block_size=0):
"""
Naive slow and accurate implementation. Base for all our tests.
Converts a number to a string of bytes.
:param number: the number to convert
:param block_size: the number of bytes to output. If the number encoded to
bytes is less than this, the block will be zero-padded. When not given,
the returned block is not padded.
:raises:
``OverflowError`` when block_size is given and the number takes up more
bytes than fit into the block.
"""
if number < 0:
raise ValueError("Negative numbers cannot be used: %d" % number)
# Do some bounds checking
needed_bytes = builtins.integer_byte_length(number)
if block_size > 0:
if needed_bytes > block_size:
raise OverflowError("Needed %i bytes for number, but block size "
"is %i" % (needed_bytes, block_size))
# Convert the number to bytes.
if number == 0:
raw_bytes = [ZERO_BYTE]
else:
raw_bytes = []
num = number
while num > 0:
raw_bytes.insert(0, builtins.byte(num & 0xFF))
num >>= 8
# Pad with zeroes to fill the block
if block_size > 0:
padding_size = (block_size - needed_bytes)
if number == 0:
padding_size -= 1
padding = ZERO_BYTE * padding_size
else:
padding = EMPTY_BYTE
return padding + EMPTY_BYTE.join(raw_bytes)
def uint_to_bytes_naive_array_based(uint, chunk_size=0):
"""
Converts an integer into bytes.
:param uint:
Unsigned integer value.
:param chunk_size:
Chunk size.
:returns:
Bytes.
"""
if uint < 0:
raise ValueError('Negative numbers cannot be used: %i' % uint)
if uint == 0:
bytes_count = 1
else:
bytes_count = integer_byte_length(uint)
byte_array = array('B', [0] * bytes_count)
for count in range(bytes_count - 1, -1, -1):
byte_array[count] = uint & 0xff
uint >>= 8
raw_bytes = byte_array.tostring()
if chunk_size > 0:
# Bounds checking. We're not doing this up-front because the
# most common use case is not specifying a chunk size. In the worst
# case, the number will already have been converted to bytes above.
length = len(raw_bytes)
bytes_needed = bytes_count
if bytes_needed > chunk_size:
raise OverflowError(
"Need %d bytes for number, but chunk size is %d" %
(bytes_needed, chunk_size)
)
remainder = length % chunk_size
if remainder:
raw_bytes = (chunk_size - remainder) * ZERO_BYTE + raw_bytes
return raw_bytes
def uint_to_bytes_naive_array_based(uint, chunk_size=0):
"""
Converts an integer into bytes.
:param uint:
Unsigned integer value.
:param chunk_size:
Chunk size.
:returns:
Bytes.
"""
if uint < 0:
raise ValueError("Negative numbers cannot be used: %i" % uint)
if uint == 0:
bytes_count = 1
else:
bytes_count = builtins.integer_byte_length(uint)
byte_array = array.array("B", [0] * bytes_count)
for count in builtins.range(bytes_count - 1, -1, -1):
byte_array[count] = uint & 0xff
uint >>= 8
raw_bytes = byte_array.tostring()
if chunk_size > 0:
# Bounds checking. We're not doing this up-front because the
# most common use case is not specifying a chunk size. In the worst
# case, the number will already have been converted to bytes above.
length = len(raw_bytes)
bytes_needed = bytes_count
if bytes_needed > chunk_size:
raise OverflowError(
"Need %d bytes for number, but chunk size is %d" %
(bytes_needed, chunk_size))
remainder = length % chunk_size
if remainder:
raw_bytes = (chunk_size - remainder) * ZERO_BYTE + raw_bytes
return raw_bytes
def test_byte_length_zero_if_zero(self): self.assertEqual(builtins.integer_byte_length(0), 0) self.assertEqual(_alt_builtins.integer_byte_length_shift_counting(0), 0) self.assertEqual(_alt_builtins.integer_byte_length_word_aligned(0), 0)
def test_byte_length_zero_if_zero(self): self.assertEqual(integer_byte_length(0), 0) self.assertEqual(integer_byte_length_shift_counting(0), 0) self.assertEqual(integer_byte_length_word_aligned(0), 0)