Command Cheat Sheet

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Command Cheat Sheet

Python 基本用語

  • Bytes $\to$ Hex 
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      >>> example_str = b'\x17\x10\x06Ar\xe4G\xc9\xb5\xd7y\xbc'
  >>> example_str.hex()
  '1710064172e447c9b5d779bc'
  • Hex $\to$ String 
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      >>> bytes.fromhex('68656c6c6f').decode('utf-8')
  'hello'
  >>> # or
  >>> import binascii
  >>> binascii.unhexlify('68656c6c6f')
  b'hello"
    
  >>> # or
  >>> import codecs
  >>> decode_hex = codecs.getdecoder("hex_codec")
  >>> decode_hex(s)[0]
  b'hello'
  • String $\to$ Hex 
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      >>> str= 'linuxhint'.encode('utf-8')
  >>> str.hex()
  '6c696e757868696e74'
  • Hex(String Type) $\to$ Decimal 
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      >>> a = '123456'
  >>> int(a, 16)
  1193046
  • Decimal $\to$ Hex 
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      >>> a = 1234
  >>> hex(a)
  '0x4d2'
  • Hex $\to$ Binary 
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      >>> bin(int('abc', 16))[2:].zfill(8)
  '101010111100'
  • String $\to$ Binary :::info if you’d like to do this transformation, 1st conversion is better ::: 
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      # string to hex to binary
  >>> bin(int('I love CNS'.encode('utf-8').hex(), 16))[2:].zfill(8)
  '1001001001000000110110001101111011101100110010100100000010000110100111001010011'
  >>> ''.join(format(ord(x), 'b') for x in 'I love CNS')
  '10010011000001101100110111111101101100101100000100001110011101010011'
  • Byte $\to$ String 
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      >>> b'abc\n'.decode('utf-8')
  'abc\n'
  • Binary $\to$ Hex 
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      >>> hex(int('010110', 2))
  '0x16'
  >>> hex(int('0000010010001101', 2))
  '0x48d'
  • Binary $\to$ Hex $\to$ String 
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      def binToHexa(n):
      bnum = int(n)
      temp = 0
      mul = 1
      count = 1
      hexaDeciNum = ['0'] * 100
      i = 0
      while bnum != 0:
          rem = bnum % 10
          temp = temp + (rem*mul)
          if count % 4 == 0:
              if temp < 10:
                  hexaDeciNum[i] = chr(temp+48)
              else:
                  hexaDeciNum[i] = chr(temp+55)
              mul = 1
              temp = 0
              count = 1
              i = i+1
          else:
              mul = mul*2
              count = count+1
          bnum = int(bnum/10)
      if count != 1:
          hexaDeciNum[i] = chr(temp+48)
      if count == 1:
          i = i-1
      hex_string = ''
      while i >= 0:
          hex_string += hexaDeciNum[i]
          i = i-1
      if hex_string == '':
          hex_string = '00'
      return hex_string
    
  plaintext_hex = binToHexa(plaintext_bin).encode().hex() 
  print(bytes.fromhex(plaintext_hex).decode())
  • Decimal(int type) $\to$ Hex(String type) 
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      >>> '{0:0>2x}'.format(0)
  '00'
  >>> '{0:0>2x}'.format(255)
  'ff'
  >>> '{:x}'.format(290275030195850039473456618367455885069965748851278076756743720446703314517401359267322769037469251445384426639837648598397)
  '7069636f4354467b6d347962335f54683073655f6d337335346733735f3472335f646966757272656e745f313737323733357d'
  • String(str type) $\iff$ Decimal 
      >>> chr(97)
  'a'
  >>> ord('a')
  97
  • Decimal $\to$ Binary 
      >>> bin(10)
  '0b1010'
  • Decimal $\to$ Bytes Type 
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      >>> bytes([10])
  b'\n'
  >>> bytes([70])
  b'F'
  • Array $\to$ List 
      >>> import numpy as np
  >>> a = np.array([1,2,3])
  >>> a.tolist()
  [1, 2, 3]

Python 組合技

  • XOR Two Decimal 
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      >>> from itertools import cycle
  >>> def hex_xor(s1, s2):
  ...    b = bytearray()
  ...    for c1, c2 in zip(bytes.fromhex(s1), cycle(bytes.fromhex(s2))):
  ...        b.append(c1 ^ c2)
  ...    return b.hex()
  >>> s1 = 'aaab'
  >>> s2 = 'ccbc'
  >>> hex_xor(s1, s2)
  '6617'
  • Decimal $\to$ Ascii String 
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      >>> tmp = 4028375274964940959047587304025089628177332141172593013450629550958369516176531641246900741346661851279741
  >>> bytes.fromhex('{:x}'.format(tmp)).decode('utf-8')
  'picoCTF{p0ll4rd_f4ct0r1z4at10n_FTW_7c8625a1}'

Python 酷酷的寫法

  • string倒續輸出 
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      >>> "galf"[::-1]
  'flag'
  • 取2的補數(取有號數的負號) 
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      >>> import ctypes
  >>> a = 0x17c7cc6e
  >>> ctypes.c_int32(a).value
  398969966
  >>> b = 0xc158a854
  >>> ctypes.c_int32(b).value
  -1051154348

Linux 奇技淫巧語法