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Diffstat (limited to 'frozen_deps/Cryptodome/Util/py3compat.py')
-rw-r--r-- | frozen_deps/Cryptodome/Util/py3compat.py | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/frozen_deps/Cryptodome/Util/py3compat.py b/frozen_deps/Cryptodome/Util/py3compat.py new file mode 100644 index 0000000..40ef752 --- /dev/null +++ b/frozen_deps/Cryptodome/Util/py3compat.py @@ -0,0 +1,164 @@ +# -*- coding: utf-8 -*- +# +# Util/py3compat.py : Compatibility code for handling Py3k / Python 2.x +# +# Written in 2010 by Thorsten Behrens +# +# =================================================================== +# The contents of this file are dedicated to the public domain. To +# the extent that dedication to the public domain is not available, +# everyone is granted a worldwide, perpetual, royalty-free, +# non-exclusive license to exercise all rights associated with the +# contents of this file for any purpose whatsoever. +# No rights are reserved. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# =================================================================== + +"""Compatibility code for handling string/bytes changes from Python 2.x to Py3k + +In Python 2.x, strings (of type ''str'') contain binary data, including encoded +Unicode text (e.g. UTF-8). The separate type ''unicode'' holds Unicode text. +Unicode literals are specified via the u'...' prefix. Indexing or slicing +either type always produces a string of the same type as the original. +Data read from a file is always of '''str'' type. + +In Python 3.x, strings (type ''str'') may only contain Unicode text. The u'...' +prefix and the ''unicode'' type are now redundant. A new type (called +''bytes'') has to be used for binary data (including any particular +''encoding'' of a string). The b'...' prefix allows one to specify a binary +literal. Indexing or slicing a string produces another string. Slicing a byte +string produces another byte string, but the indexing operation produces an +integer. Data read from a file is of '''str'' type if the file was opened in +text mode, or of ''bytes'' type otherwise. + +Since PyCryptodome aims at supporting both Python 2.x and 3.x, the following helper +functions are used to keep the rest of the library as independent as possible +from the actual Python version. + +In general, the code should always deal with binary strings, and use integers +instead of 1-byte character strings. + +b(s) + Take a text string literal (with no prefix or with u'...' prefix) and + make a byte string. +bchr(c) + Take an integer and make a 1-character byte string. +bord(c) + Take the result of indexing on a byte string and make an integer. +tobytes(s) + Take a text string, a byte string, or a sequence of character taken from + a byte string and make a byte string. +""" + +import sys +import abc + + +if sys.version_info[0] == 2: + def b(s): + return s + def bchr(s): + return chr(s) + def bstr(s): + return str(s) + def bord(s): + return ord(s) + def tobytes(s, encoding="latin-1"): + if isinstance(s, unicode): + return s.encode(encoding) + elif isinstance(s, str): + return s + elif isinstance(s, bytearray): + return bytes(s) + else: + return ''.join(s) + def tostr(bs): + return bs + def byte_string(s): + return isinstance(s, str) + + # In Pyton 2.x, StringIO is a stand-alone module + from StringIO import StringIO as BytesIO + + from sys import maxint + + if sys.version_info[1] < 7: + import types + _memoryview = types.NoneType + else: + _memoryview = memoryview + + iter_range = xrange + + def is_native_int(x): + return isinstance(x, (int, long)) + + def is_string(x): + return isinstance(x, basestring) + + ABC = abc.ABCMeta('ABC', (object,), {'__slots__': ()}) + +else: + def b(s): + return s.encode("latin-1") # utf-8 would cause some side-effects we don't want + def bchr(s): + return bytes([s]) + def bstr(s): + if isinstance(s,str): + return bytes(s,"latin-1") + else: + return bytes(s) + def bord(s): + return s + def tobytes(s, encoding="latin-1"): + if isinstance(s, bytes): + return s + elif isinstance(s, bytearray): + return bytes(s) + elif isinstance(s,str): + return s.encode(encoding) + else: + return bytes([s]) + def tostr(bs): + return bs.decode("latin-1") + def byte_string(s): + return isinstance(s, bytes) + + # In Python 3.x, StringIO is a sub-module of io + from io import BytesIO + from sys import maxsize as maxint + + _memoryview = memoryview + + iter_range = range + + def is_native_int(x): + return isinstance(x, int) + + def is_string(x): + return isinstance(x, str) + + from abc import ABC + + +def _copy_bytes(start, end, seq): + """Return an immutable copy of a sequence (byte string, byte array, memoryview) + in a certain interval [start:seq]""" + + if isinstance(seq, _memoryview): + return seq[start:end].tobytes() + elif isinstance(seq, bytearray): + return bytes(seq[start:end]) + else: + return seq[start:end] + +del sys +del abc |