本文整理汇总了Python中Crypto.Util._counter._newLE方法的典型用法代码示例。如果您正苦于以下问题：Python _counter._newLE方法的具体用法？Python _counter._newLE怎么用？Python _counter._newLE使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Crypto.Util._counter的用法示例。
在下文中一共展示了_counter._newLE方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: new
# 需要导入模块: from Crypto.Util import _counter [as 别名]
# 或者: from Crypto.Util._counter import _newLE [as 别名]
def new(nbits, prefix=b(""), suffix=b(""), initial_value=1, overflow=0, little_endian=False, allow_wraparound=False, disable_shortcut=False):
"""Create a stateful counter block function suitable for CTR encryption modes.
Each call to the function returns the next counter block.
Each counter block is made up by three parts::
prefix || counter value || postfix
The counter value is incremented by one at each call.
:Parameters:
nbits : integer
Length of the desired counter, in bits. It must be a multiple of 8.
prefix : byte string
The constant prefix of the counter block. By default, no prefix is
used.
suffix : byte string
The constant postfix of the counter block. By default, no suffix is
used.
initial_value : integer
The initial value of the counter. Default value is 1.
little_endian : boolean
If True, the counter number will be encoded in little endian format.
If False (default), in big endian format.
allow_wraparound : boolean
If True, the function will raise an *OverflowError* exception as soon
as the counter wraps around. If False (default), the counter will
simply restart from zero.
disable_shortcut : boolean
If True, do not make ciphers from `Crypto.Cipher` bypass the Python
layer when invoking the counter block function.
If False (default), bypass the Python layer.
:Returns:
The counter block function.
"""
# Sanity-check the message size
(nbytes, remainder) = divmod(nbits, 8)
if remainder != 0:
# In the future, we might support arbitrary bit lengths, but for now we don't.
raise ValueError("nbits must be a multiple of 8; got %d" % (nbits,))
if nbytes < 1:
raise ValueError("nbits too small")
elif nbytes > 0xffff:
raise ValueError("nbits too large")
initval = _encode(initial_value, nbytes, little_endian)
if little_endian:
return _counter._newLE(bstr(prefix), bstr(suffix), initval, allow_wraparound=allow_wraparound, disable_shortcut=disable_shortcut)
else:
return _counter._newBE(bstr(prefix), bstr(suffix), initval, allow_wraparound=allow_wraparound, disable_shortcut=disable_shortcut)