mirror of
https://github.com/TheAlgorithms/Python.git
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176 lines
4.1 KiB
Python
176 lines
4.1 KiB
Python
import math
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def rearrange(bitString32):
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"""[summary]
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Regroups the given binary string.
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Arguments:
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bitString32 {[string]} -- [32 bit binary]
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Raises:
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ValueError -- [if the given string not are 32 bit binary string]
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Returns:
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[string] -- [32 bit binary string]
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>>> rearrange('1234567890abcdfghijklmnopqrstuvw')
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'pqrstuvwhijklmno90abcdfg12345678'
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"""
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if len(bitString32) != 32:
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raise ValueError("Need length 32")
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newString = ""
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for i in [3, 2,1,0]:
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newString += bitString32[8*i:8*i+8]
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return newString
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def reformatHex(i):
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"""[summary]
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Converts the given integer into 8-digit hex number.
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Arguments:
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i {[int]} -- [integer]
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>>> reformatHex(666)
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'9a020000'
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"""
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hexrep = format(i, '08x')
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thing = ""
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for i in [3, 2,1,0]:
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thing += hexrep[2*i:2*i+2]
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return thing
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def pad(bitString):
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"""[summary]
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Fills up the binary string to a 512 bit binary string
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Arguments:
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bitString {[string]} -- [binary string]
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Returns:
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[string] -- [binary string]
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"""
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startLength = len(bitString)
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bitString += '1'
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while len(bitString) % 512 != 448:
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bitString += '0'
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lastPart = format(startLength, '064b')
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bitString += rearrange(lastPart[32:]) + rearrange(lastPart[:32])
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return bitString
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def getBlock(bitString):
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"""[summary]
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Iterator:
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Returns by each call a list of length 16 with the 32 bit
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integer blocks.
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Arguments:
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bitString {[string]} -- [binary string >= 512]
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"""
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currPos = 0
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while currPos < len(bitString):
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currPart = bitString[currPos:currPos+512]
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mySplits = []
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for i in range(16):
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mySplits.append(int(rearrange(currPart[32*i:32*i+32]), 2))
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yield mySplits
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currPos += 512
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def not32(i):
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'''
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>>> not32(34)
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4294967261
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'''
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i_str = format(i, '032b')
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new_str = ''
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for c in i_str:
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new_str += '1' if c == '0' else '0'
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return int(new_str, 2)
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def sum32(a, b):
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'''
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'''
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return (a + b) % 2**32
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def leftrot32(i, s):
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return (i << s) ^ (i >> (32-s))
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def md5me(testString):
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"""[summary]
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Returns a 32-bit hash code of the string 'testString'
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Arguments:
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testString {[string]} -- [message]
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"""
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bs = ''
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for i in testString:
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bs += format(ord(i), '08b')
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bs = pad(bs)
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tvals = [int(2**32 * abs(math.sin(i+1))) for i in range(64)]
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a0 = 0x67452301
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b0 = 0xefcdab89
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c0 = 0x98badcfe
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d0 = 0x10325476
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s = [7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
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5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, \
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4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, \
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6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21 ]
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for m in getBlock(bs):
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A = a0
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B = b0
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C = c0
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D = d0
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for i in range(64):
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if i <= 15:
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#f = (B & C) | (not32(B) & D)
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f = D ^ (B & (C ^ D))
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g = i
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elif i <= 31:
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#f = (D & B) | (not32(D) & C)
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f = C ^ (D & (B ^ C))
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g = (5*i+1) % 16
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elif i <= 47:
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f = B ^ C ^ D
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g = (3*i+5) % 16
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else:
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f = C ^ (B | not32(D))
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g = (7*i) % 16
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dtemp = D
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D = C
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C = B
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B = sum32(B, leftrot32((A + f + tvals[i] + m[g]) % 2**32, s[i]))
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A = dtemp
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a0 = sum32(a0, A)
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b0 = sum32(b0, B)
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c0 = sum32(c0, C)
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d0 = sum32(d0, D)
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digest = reformatHex(a0) + reformatHex(b0) + \
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reformatHex(c0) + reformatHex(d0)
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return digest
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def test():
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assert md5me("") == "d41d8cd98f00b204e9800998ecf8427e"
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assert md5me(
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"The quick brown fox jumps over the lazy dog") == "9e107d9d372bb6826bd81d3542a419d6"
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print("Success.")
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if __name__ == "__main__":
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test()
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import doctest
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doctest.testmod()
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