Files
OALabs-hashdb/algorithms/add_ror13.py
T
2021-10-06 15:33:15 -04:00

54 lines
1.6 KiB
Python

#!/usr/bin/env python
########################################################################
# Copyright 2012 Mandiant
# Copyright 2014 FireEye
#
# Mandiant licenses this file to you under the Apache License, Version
# 2.0 (the "License"); you may not use this file except in compliance with the
# License. You may obtain a copy of the License at:
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied. See the License for the specific language governing
# permissions and limitations under the License.
#
# Reference:
# https://github.com/mandiant/flare-ida/blob/master/shellcode_hashes/make_sc_hash_db.py
#
########################################################################
DESCRIPTION = "ADD and ROR 13"
TYPE = 'unsigned_int'
TEST_1 = 3953483048
ROTATE_BITMASK = {
8: 0xff,
16: 0xffff,
32: 0xffffffff,
64: 0xffffffffffffffff,
}
def ror(inVal, numShifts, dataSize=32):
'''rotate right instruction emulation'''
if numShifts == 0:
return inVal
if (numShifts < 0) or (numShifts > dataSize):
raise ValueError('Bad numShifts')
if (dataSize != 8) and (dataSize != 16) and (dataSize != 32) and (dataSize != 64):
raise ValueError('Bad dataSize')
bitMask = ROTATE_BITMASK[dataSize]
return bitMask & ((inVal >> numShifts) | (inVal << (dataSize-numShifts)))
def hash(data):
val = 0
for i in data:
val += i
val = ror(val, 0xd, 32)
return val