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# Author: Trevor Perrin
# See the LICENSE file for legal information regarding use of this file.
"""Miscellaneous functions to mask Python version differences."""
import sys
import platform
import hmac
if sys.version_info >= (3,0):
def compat26Str(x): return x
else:
# Python 2.6 requires strings instead of bytearrays in a couple places,
# so we define this function so it does the conversion if needed.
# same thing with very old 2.7 versions
# or on Jython
if sys.version_info < (2, 7) or sys.version_info < (2, 7, 4) or platform.system() == 'Java':
def compat26Str(x): return str(x)
else:
def compat26Str(x): return x
if hasattr(hmac, 'compare_digest'):
ct_compare_digest = hmac.compare_digest
else:
def ct_compare_digest(val_a, val_b):
"""Compares if string like objects are equal. Constant time."""
if len(val_a) != len(val_b):
return False
result = 0
for x, y in zip(val_a, val_b):
result |= x ^ y
return result == 0
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