diff options
Diffstat (limited to 'rsa/transform.py')
| -rw-r--r-- | rsa/transform.py | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/rsa/transform.py b/rsa/transform.py index c740b2d..63cbc14 100644 --- a/rsa/transform.py +++ b/rsa/transform.py @@ -14,10 +14,10 @@ # See the License for the specific language governing permissions and # limitations under the License. -'''Data transformation functions. +"""Data transformation functions. From bytes to a number, number to bytes, etc. -''' +""" from __future__ import absolute_import @@ -26,6 +26,7 @@ try: # Using psyco (if available) cuts down the execution time on Python 2.5 # at least by half. import psyco + psyco.full() except ImportError: pass @@ -37,7 +38,7 @@ from rsa._compat import is_integer, b, byte, get_word_alignment, ZERO_BYTE, EMPT def bytes2int(raw_bytes): - r'''Converts a list of bytes or an 8-bit string to an integer. + """Converts a list of bytes or an 8-bit string to an integer. When using unicode strings, encode it to some encoding like UTF8 first. @@ -46,13 +47,13 @@ def bytes2int(raw_bytes): >>> bytes2int('\x80@\x0f') 8405007 - ''' + """ return int(binascii.hexlify(raw_bytes), 16) def _int2bytes(number, block_size=None): - r'''Converts a number to a string of bytes. + """Converts a number to a string of bytes. Usage:: @@ -78,11 +79,12 @@ def _int2bytes(number, block_size=None): @throws OverflowError when block_size is given and the number takes up more bytes than fit into the block. - ''' + """ + # Type checking if not is_integer(number): raise TypeError("You must pass an integer for 'number', not %s" % - number.__class__) + number.__class__) if number < 0: raise ValueError('Negative numbers cannot be used: %i' % number) @@ -99,7 +101,7 @@ def _int2bytes(number, block_size=None): if block_size and block_size > 0: if needed_bytes > block_size: raise OverflowError('Needed %i bytes for number, but block size ' - 'is %i' % (needed_bytes, block_size)) + 'is %i' % (needed_bytes, block_size)) # Convert the number to bytes. while number > 0: @@ -116,7 +118,7 @@ def _int2bytes(number, block_size=None): def bytes_leading(raw_bytes, needle=ZERO_BYTE): - ''' + """ Finds the number of prefixed byte occurrences in the haystack. Useful when you want to deal with padding. @@ -127,7 +129,8 @@ def bytes_leading(raw_bytes, needle=ZERO_BYTE): The byte to count. Default \000. :returns: The number of leading needle bytes. - ''' + """ + leading = 0 # Indexing keeps compatibility between Python 2.x and Python 3.x _byte = needle[0] @@ -140,7 +143,7 @@ def bytes_leading(raw_bytes, needle=ZERO_BYTE): def int2bytes(number, fill_size=None, chunk_size=None, overflow=False): - ''' + """ Convert an unsigned integer to bytes (base-256 representation):: Does not preserve leading zeros if you don't specify a chunk size or @@ -172,7 +175,8 @@ def int2bytes(number, fill_size=None, chunk_size=None, overflow=False): bytes than fit into the block. This requires the ``overflow`` argument to this function to be set to ``False`` otherwise, no error will be raised. - ''' + """ + if number < 0: raise ValueError("Number must be an unsigned integer: %d" % number) @@ -202,8 +206,8 @@ def int2bytes(number, fill_size=None, chunk_size=None, overflow=False): if fill_size and fill_size > 0: if not overflow and length > fill_size: raise OverflowError( - "Need %d bytes for number, but fill size is %d" % - (length, fill_size) + "Need %d bytes for number, but fill size is %d" % + (length, fill_size) ) raw_bytes = raw_bytes.rjust(fill_size, ZERO_BYTE) elif chunk_size and chunk_size > 0: @@ -216,5 +220,5 @@ def int2bytes(number, fill_size=None, chunk_size=None, overflow=False): if __name__ == '__main__': import doctest - doctest.testmod() + doctest.testmod() |