pwnlib.util.cyclic — Generation of unique sequences

pwnlib.util.cyclic.cyclic(length = None, alphabet = string.ascii_lowercase, n = 4) → list/str

A simple wrapper over de_bruijn(). This function returns at most length elements.

If the given alphabet is a string, a string is returned from this function. Otherwise a list is returned.

参数:

• length – The desired length of the list or None if the entire sequence is desired.
• alphabet – List or string to generate the sequence over.
• n (int) – The length of subsequences that should be unique.

Example

>>> cyclic(alphabet = "ABC", n = 3)
'AAABAACABBABCACBACCBBBCBCCC'
>>> cyclic(20)
'aaaabaaacaaadaaaeaaa'
>>> alphabet, n = range(30), 3
>>> len(alphabet)**n, len(cyclic(alphabet = alphabet, n = n))
(27000, 27000)

pwnlib.util.cyclic.cyclic_find(subseq, alphabet = string.ascii_lowercase, n = None) → int

Calculates the position of a substring into a De Bruijn sequence.

参数:

• subseq – The subsequence to look for. This can be a string, a list or an integer. If an integer is provided it will be packed as a little endian integer.
• alphabet – List or string to generate the sequence over.
• n (int) – The length of subsequences that should be unique.

Examples

>>> cyclic_find(cyclic(1000)[514:518])
514
>>> cyclic_find(0x61616162)
4

pwnlib.util.cyclic.cyclic_metasploit(length = None, sets = [ string.ascii_uppercase, string.ascii_lowercase, string.digits ]) → str

A simple wrapper over metasploit_pattern(). This function returns a string of length length.

参数:

• length – The desired length of the string or None if the entire sequence is desired.
• sets – List of strings to generate the sequence over.

Example

>>> cyclic_metasploit(32)
'Aa0Aa1Aa2Aa3Aa4Aa5Aa6Aa7Aa8Aa9Ab'
>>> cyclic_metasploit(sets = ["AB","ab","12"])
'Aa1Aa2Ab1Ab2Ba1Ba2Bb1Bb2'
>>> cyclic_metasploit()[1337:1341]
'5Bs6'
>>> len(cyclic_metasploit())
20280

pwnlib.util.cyclic.cyclic_metasploit_find(subseq, sets = [ string.ascii_uppercase, string.ascii_lowercase, string.digits ]) → int

Calculates the position of a substring into a Metasploit Pattern sequence.

参数:

• subseq – The subsequence to look for. This can be a string or an integer. If an integer is provided it will be packed as a little endian integer.
• sets – List of strings to generate the sequence over.

Examples

>>> cyclic_metasploit_find(cyclic_metasploit(1000)[514:518])
514
>>> cyclic_metasploit_find(0x61413161)
4

pwnlib.util.cyclic.de_bruijn(alphabet = string.ascii_lowercase, n = 4) → generator

Generator for a sequence of unique substrings of length n. This is implemented using a De Bruijn Sequence over the given alphabet.

The returned generator will yield up to len(alphabet)**n elements.

参数:

• alphabet – List or string to generate the sequence over.
• n (int) – The length of subsequences that should be unique.

pwnlib.util.cyclic.metasploit_pattern(sets = [ string.ascii_uppercase, string.ascii_lowercase, string.digits ]) → generator

Generator for a sequence of characters as per Metasploit Framework’s Rex::Text.pattern_create (aka pattern_create.rb).

The returned generator will yield up to len(sets) * reduce(lambda x,y: x*y, map(len, sets)) elements.

参数:sets – List of strings to generate the sequence over.