[Tutor] i dont understand this code
Can anyone help me out in understanding this code
#
import os
rotationMatrix1 = [7, 1, 5, 3, 0, 6, 2, 5, 2, 3, 0, 6, 1, 7, 6, 1, 5, 2, 7,
1, 0, 3, 7, 6, 1, 0, 5, 2, 1, 5, 7, 3, 2, 0, 6]
rotationMatrix2 = [1, 6, 2, 5, 7, 3, 0, 7, 1, 6, 2, 5, 0, 3, 0, 6, 5, 1, 1,
7, 2, 5, 2, 3, 7, 6, 2, 1, 3, 7, 6, 5, 0, 1, 7]
keyboardDict = { 2: '1', 3: '2', 4: '3', 5: '4', 6: '5', 7: '6', 8:
'7', 9: '8', 10: '9', 11: '0',
16: 'q', 17: 'w', 18: 'e', 19: 'r', 20: 't', 21: 'y', 22:
'u', 23: 'i', 24: 'o', 25: 'p',
30: 'a', 31: 's', 32: 'd', 33: 'f', 34: 'g', 35: 'h', 36:
'j', 37: 'k', 38: 'l',
44: 'z', 45: 'x', 46: 'c', 47: 'v', 48: 'b', 49: 'n', 50:
'm' }
def keyboardEncToAscii(inKey):
out = ""
for c in inKey:
if c == 0: return out
if c in keyboardDict: out += keyboardDict[c]
else: return ""
return out
def decryptHash(hash, key, rotationMatrix):
outhash = []
for i in range(0, len(hash)):
outhash.append(((hash[i] <<
(rotationMatrix[7*key+i])) & 0xFF) | (hash[i] >>
(8-rotationMatrix[7*key+i])))
return outhash
print("")
print("hexa decimal code")
print("hexadecimal code from which the password can be calculated,")
print("07088120410C")
print("")
print("Please enter the code: ")
code = raw_input()
hash = []
for i in range(1, len(code) // 2):
hash.append(int(code[2*i]+code[2*i+1],16))
key = int(code[0:2], 16) % 5
password = keyboardEncToAscii(decryptHash(hash, key, rotationMatrix1))
if password == "":
password = keyboardEncToAscii(decryptHash(hash, key,
rotationMatrix2))
if password == "":
print("The password could not be calculated. Bummer.")
else:
print("The password is: " + password)
if (os.name == 'nt'):
print("Press a key to exit...")
raw_input()
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Re: [Tutor] i dont understand this code
On 2/22/2014 7:26 AM, piyush joshi wrote:
Can anyone help me out in understanding this code
Your question is kinda vague. Exactly what do you not understand?
#
import os
rotationMatrix1 = [7, 1, 5, 3, 0, 6, 2, 5, 2, 3, 0, 6, 1, 7, 6, 1, 5,
2, 7, 1, 0, 3, 7, 6, 1, 0, 5, 2, 1, 5, 7, 3, 2, 0, 6]
rotationMatrix2 = [1, 6, 2, 5, 7, 3, 0, 7, 1, 6, 2, 5, 0, 3, 0, 6, 5,
1, 1, 7, 2, 5, 2, 3, 7, 6, 2, 1, 3, 7, 6, 5, 0, 1, 7]
keyboardDict = { 2: '1', 3: '2', 4: '3', 5: '4', 6: '5', 7:
'6', 8: '7', 9: '8', 10: '9', 11: '0',
16: 'q', 17: 'w', 18: 'e', 19: 'r', 20: 't', 21: 'y',
22: 'u', 23: 'i', 24: 'o', 25: 'p',
30: 'a', 31: 's', 32: 'd', 33: 'f', 34: 'g', 35: 'h',
36: 'j', 37: 'k', 38: 'l',
44: 'z', 45: 'x', 46: 'c', 47: 'v', 48: 'b', 49: 'n',
50: 'm' }
def keyboardEncToAscii(inKey):
out = ""
for c in inKey:
if c == 0: return out
if c in keyboardDict: out +=
keyboardDict[c]
else: return ""
return out
def decryptHash(hash, key, rotationMatrix):
outhash = []
for i in range(0, len(hash)):
outhash.append(((hash[i] << (rotationMatrix[7*key+i])) & 0xFF) |
(hash[i] >> (8-rotationMatrix[7*key+i])))
return outhash
print("")
print("hexa decimal code")
print("hexadecimal code from which the password can be calculated,")
print("07088120410C")
print("")
print("Please enter the code: ")
code = raw_input()
hash = []
for i in range(1, len(code) // 2):
hash.append(int(code[2*i]+code[2*i+1],16))
key = int(code[0:2], 16) % 5
password = keyboardEncToAscii(decryptHash(hash, key, rotationMatrix1))
if password == "":
password = keyboardEncToAscii(decryptHash(hash, key,
rotationMatrix2))
if password == "":
print("The password could not be calculated. Bummer.")
else:
print("The password is: " + password)
if (os.name == 'nt'):
print("Press a key to exit...")
raw_input()
Re: [Tutor] i dont understand this code
On 22/02/14 12:26, piyush joshi wrote:
Can anyone help me out in understanding this code
Sure, but it's an quite a lot of code to describe line by line.
Is there anything specific you need help with?
import os
rotationMatrix1 = [7, 1, 5, 3, 0, 6, 2, 5, 2, 3, 0, 6, 1, 7, 6, 1, 5, 2,
7, 1, 0, 3, 7, 6, 1, 0, 5, 2, 1, 5, 7, 3, 2, 0, 6]
rotationMatrix2 = [1, 6, 2, 5, 7, 3, 0, 7, 1, 6, 2, 5, 0, 3, 0, 6, 5, 1,
1, 7, 2, 5, 2, 3, 7, 6, 2, 1, 3, 7, 6, 5, 0, 1, 7]
keyboardDict = { 2: '1', 3: '2', 4: '3', 5: '4', 6: '5', 7: '6',
8: '7', 9: '8', 10: '9', 11: '0',
16: 'q', 17: 'w', 18: 'e', 19: 'r', 20: 't', 21: 'y',
22: 'u', 23: 'i', 24: 'o', 25: 'p',
30: 'a', 31: 's', 32: 'd', 33: 'f', 34: 'g', 35: 'h',
36: 'j', 37: 'k', 38: 'l',
44: 'z', 45: 'x', 46: 'c', 47: 'v', 48: 'b', 49: 'n',
50: 'm' }
def keyboardEncToAscii(inKey):
out = ""
for c in inKey:
if c == 0: return out
if c in keyboardDict: out +=
keyboardDict[c]
else: return ""
return out
def decryptHash(hash, key, rotationMatrix):
outhash = []
for i in range(0, len(hash)):
outhash.append(((hash[i] <<
(rotationMatrix[7*key+i])) & 0xFF) | (hash[i] >>
(8-rotationMatrix[7*key+i])))
return outhash
print("")
print("hexa decimal code")
print("hexadecimal code from which the password can be calculated,")
print("07088120410C")
print("")
print("Please enter the code: ")
code = raw_input()
hash = []
for i in range(1, len(code) // 2):
hash.append(int(code[2*i]+code[2*i+1],16))
key = int(code[0:2], 16) % 5
password = keyboardEncToAscii(decryptHash(hash, key, rotationMatrix1))
if password == "":
password = keyboardEncToAscii(decryptHash(hash, key,
rotationMatrix2))
if password == "":
print("The password could not be calculated. Bummer.")
else:
print("The password is: " + password)
if (os.name == 'nt'):
print("Press a key to exit...")
raw_input()
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.flickr.com/photos/alangauldphotos
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