# Eikonal Blog

## 2010.06.30

### Jaggedness

Filed under: mathematics — Tags: — sandokan65 @ 22:17

The Jaggedness of a discrete path $c_N=\{x_i \in {\Bbb R}|i=0,N| x_0=a, x_N=b\}$ is defined by:

$J = \frac1{N-1} \sum_{i=0}^{N-2} \frac12 (1-\hbox{sign}(\Delta x_i \Delta x_{i+1}))$

where $\Delta x_i :\equiv x_{i+1} - x_i$.

Source: “Jaggedness of Path Integral Trajectories” by Aleksandar Bogojevic, Antun Balaz, Aleksandar Belic (2005.09.10) – http://arxiv.org/abs/cond-mat/0509266.

## 2010.06.24

### MetaSploit

Filed under: Penetration Testing, VA (Vulnerability Assessment) — Tags: , — sandokan65 @ 12:59

## 2010.06.23

### Memory of things disappearing > nmap stuff > getports.awk

Filed under: infosec — Tags: , — sandokan65 @ 10:50

Code:

 #!/bin/awk -f # Lists open ports coming from nmap. # It assumes the file is in PYX format and complies with the appropriate DTD. function reset() { protocol = ""; portid = 0; state = "" service = ""; in_port = 0; } BEGIN { reset(); } /$$port/ { in_port = 1; } /$$port$/ { printf("%s %u %s %s\n", protocol, portid, state, service); reset(); } /^Aprotocol / { if (in_port) protocol =$2; } /^Aportid / { if (in_port) portid = $2; } /^Astate / { if (in_port) state =$2; } /^Aname / { if (in_port) service = \$2; } 

Related here: AWK – https://eikonal.wordpress.com/2011/09/30/awk/

## 2010.06.21

### Nipper

Filed under: infosec, VA (Vulnerability Assessment) — Tags: , — sandokan65 @ 11:53

For years I was using the CIS’ RAT (Router Assessment Tool) to evaluate the security of the configurations of various Cisco devices (firewalls, routers, switches). Then, several years ago, along came Nipper, the(n) free and open source tool doing similar assessment (but finding problems that RAT was not seeing). For several years I was using both tools on the same configurations, combining their results to get a fuller picture.

From the “No good thing stays free for long time” department: Couple of year ago the Nipper’s maker had pulled the Tenable’s Nessus bait-and-switch trick, making Nipper both closed source and commercial (non-free).

## 2010.06.20

### Rubik’s cube

Filed under: mathematics, puzzles — Tags: — sandokan65 @ 23:07

## 2010.06.17

Filed under: infosec — Tags: , — sandokan65 @ 08:42

The only tool I know residing on this niche is ntsecurity’s KerbCrack/KerbSniff (http://ntsecurity.nu/toolbox/kerbcrack/).

Usage:

kerbcrack.exe kerbcap.snf -b1 9


## 2010.06.15

### Scripting languages

Filed under: scripting, unix — Tags: , , , , , , — sandokan65 @ 14:35

Unix shells:

Windows Scripting:

Multi-language pages:

## Compiling shell scripts

Can not be done.

Related here: Unix tricks – https://eikonal.wordpress.com/2011/02/15/unix-tricks/ | SED tricks – https://eikonal.wordpress.com/2010/10/05/sed-tricks/ | Memory of things disappearing > nmap stuff > getports.awk – https://eikonal.wordpress.com/2010/06/23/memory-of-things-disappearing-nmap-stuff-getports-awk/ | AWK – https://eikonal.wordpress.com/2011/09/30/awk/

## 2010.06.12

### The Arnold Principle

• The Arnold Principle: If a notion bears a personal name, then this name is not the name of the discoverer.
• The Berry Principle: The Arnold Principle is applicable to itself.

Source: “On teaching mathematics” by V.I. Arnold – http://pauli.uni-muenster.de/~munsteg/arnold.html – an extended text of the address at the discussion on teaching of mathematics in Palais de Découverte in Paris on 7 March 1997.

Related: