121 lines
2.8 KiB
Python
121 lines
2.8 KiB
Python
"""
|
|
"""
|
|
|
|
import sys
|
|
import hashlib
|
|
|
|
|
|
def bytes(text):
|
|
"""
|
|
Convert Unicode text to UTF-8 encoded bytes.
|
|
|
|
Since Python 2.6+ and Python 3+ have similar but incompatible
|
|
signatures, this function unifies the two to keep code sane.
|
|
|
|
:param text: Unicode text to convert to bytes
|
|
:rtype: bytes (Python3), str (Python2.6+)
|
|
"""
|
|
if text is None:
|
|
return b''
|
|
|
|
if sys.version_info < (3, 0):
|
|
import __builtin__
|
|
return __builtin__.bytes(text)
|
|
else:
|
|
import builtins
|
|
if isinstance(text, builtins.bytes):
|
|
# We already have bytes, so do nothing
|
|
return text
|
|
if isinstance(text, list):
|
|
# Convert a list of integers to bytes
|
|
return builtins.bytes(text)
|
|
else:
|
|
# Convert UTF-8 text to bytes
|
|
return builtins.bytes(text, encoding='utf-8')
|
|
|
|
|
|
def quote(text):
|
|
"""
|
|
Enclose in quotes and escape internal slashes and double quotes.
|
|
|
|
:param text: A Unicode or byte string.
|
|
"""
|
|
text = bytes(text)
|
|
return b'"' + text.replace(b'\\', b'\\\\').replace(b'"', b'\\"') + b'"'
|
|
|
|
|
|
def num_to_bytes(num):
|
|
"""
|
|
Convert an integer into a four byte sequence.
|
|
|
|
:param integer num: An integer to convert to its byte representation.
|
|
"""
|
|
bval = b''
|
|
bval += bytes(chr(0xFF & (num >> 24)))
|
|
bval += bytes(chr(0xFF & (num >> 16)))
|
|
bval += bytes(chr(0xFF & (num >> 8)))
|
|
bval += bytes(chr(0xFF & (num >> 0)))
|
|
return bval
|
|
|
|
|
|
def bytes_to_num(bval):
|
|
"""
|
|
Convert a four byte sequence to an integer.
|
|
|
|
:param bytes bval: A four byte sequence to turn into an integer.
|
|
"""
|
|
num = 0
|
|
num += ord(bval[0] << 24)
|
|
num += ord(bval[1] << 16)
|
|
num += ord(bval[2] << 8)
|
|
num += ord(bval[3])
|
|
return num
|
|
|
|
|
|
def XOR(x, y):
|
|
"""
|
|
Return the results of an XOR operation on two equal length byte strings.
|
|
|
|
:param bytes x: A byte string
|
|
:param bytes y: A byte string
|
|
:rtype: bytes
|
|
"""
|
|
result = b''
|
|
for a, b in zip(x, y):
|
|
if sys.version_info < (3, 0):
|
|
result += chr((ord(a) ^ ord(b)))
|
|
else:
|
|
result += bytes([a ^ b])
|
|
return result
|
|
|
|
|
|
def hash(name):
|
|
"""
|
|
Return a hash function implementing the given algorithm.
|
|
|
|
:param name: The name of the hashing algorithm to use.
|
|
:type name: string
|
|
|
|
:rtype: function
|
|
"""
|
|
name = name.lower()
|
|
if name.startswith('sha-'):
|
|
name = 'sha' + name[4:]
|
|
if name in dir(hashlib):
|
|
return getattr(hashlib, name)
|
|
return None
|
|
|
|
|
|
def hashes():
|
|
"""
|
|
Return a list of available hashing algorithms.
|
|
|
|
:rtype: list of strings
|
|
"""
|
|
t = []
|
|
if 'md5' in dir(hashlib):
|
|
t = ['MD5']
|
|
if 'md2' in dir(hashlib):
|
|
t += ['MD2']
|
|
hashes = ['SHA-' + h[3:] for h in dir(hashlib) if h.startswith('sha')]
|
|
return t + hashes
|