每日彙整: 2018-11-16

樹莓派、樹莓派之學習、樹莓派之教育

OpenWrt 的世界︰樹莓派 3B 【路由器】移星轉斗《四‧五》 Scapy 四‧原力覺醒

這時海之涯的另一端正是『拓荒』的時代，1774 年出生的 Johnny Chapman ，譜出『蘋果種子』Appleseed 的傳奇。

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Appleseed

那從一顆『蘋果種子』能見著什麼呢？是生命的強韌？或破土而出的喜悅？還是夏娃偷吃的那個？也許可以這樣說︰『火』的掌握改變了人類當時的生活，而一顆種子的傳承造就世世代代的持有。強尼‧蘋果種子所代表的『拓荒精神』──

STAR TREK
星艦迷航記
Where No One Has Gone Before
前人未至之境

──，是否終將化作『概念種子』等待時機『發芽』？

1776年7月4日，美國的大陸會議通過《獨立宣言》，宣言這個新國家是獨立的，完全脫離英國，目的是為『圖生存、求自由、謀幸福』，實現啟蒙運動的理想。之後過了一百三十九年，一九一五年三月十一日，Joseph Carl Robnett Licklider 誕生於密蘇里州的聖路易斯，不知距馬克‧吐溫的湯姆──密蘇里州聖彼得斯堡──歷險記之地有多少距離？身為浸信會牧師獨子的他，自幼喜歡玩模型飛機，展現了工程天份，終身喜好修整汽車，史稱『計算機種子』。

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Evolution_of_the_document_icon_shape

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1937 年二十二歲的 Lick 自華盛頓大學取得藝術學位，主修物理、數學、和心理學；1942 年為羅微斯特大學心理聲學的博士；1943 至 1950 年間工作於哈佛大學心理聲學實驗室，開始對『資訊科技』有興趣，於是前往 MIT 任副教授，並成為 MIT 林肯實驗室委員會的成員，推動建立工程系學生的心理學課程。那時正是美蘇『冷戰』時期，Lick 參與了『SAGE』─ Semi-Automatic Ground Environment ── 計畫，見左圖二。1957 年獲頒工程心理學會的最高榮譽 Franklin V. Taylor Award 獎；同年轉任 Beranek and Newman 高科技公司的副總裁，用他購買的第一代 PDP-1 電腦，引領大眾了解何謂『 time-sharing 』的概念；次年他被選為美國聲學學會會長。1962 年十月 Lick 被美國國防高等研究計劃署 DARPA ── 後稱 作ARPA ── 指派領導資訊處理技術辦公室 Information Processing Techniques Office (IPTO)，一九六三年，轉任領導 ARPA 的 Behavioral Sciences Command & Control Research 辦公室，在一張標題為『Members and Affiliates of the Intergalactic Computer Network』給工作同仁的備忘錄上︰
“imagined as an electronic commons open to all, ‘the main and essential medium of informational interaction for governments, institutions, corporations, and individuals.'”

宣告『銀河際網路』的願景，是促使 Internet 誕生的第一響春雷！！ 1968年 Lick 到 MIT 的電機工程系作教授，領導 MAC ── Mathematics And Computation  ── 計畫，建立了第一台分時計算系統，… 靈感鼓舞了……  Unix 的發展 ………。或許 Robert Taylor ── Xerox PARC 計算機科學實驗室和 DEC 系統研究中心的發起人 ──說的好︰
most of the significant advances in computer technology—including the work that my group did at Xerox PARC—were simply extrapolations of Lick’s vision. They were not really new visions of their own. So he was really the father of it all

─── 《一個奇想！！》

 

不知 Lick 是否預見『銀河際網路』，將衍生『網路街頭抗議』哩☆

阻斷服務攻擊

阻斷服務攻擊（英語：denial-of-service attack，縮寫：DoS attack、DoS）亦稱洪水攻擊，是一種網路攻擊手法，其目的在於使目標電腦的網路或系統資源耗盡，使服務暫時中斷或停止，導致其正常用戶無法存取。

當駭客使用網路上兩個或以上被攻陷的電腦作為「殭屍」向特定的目標發動「阻斷服務」式攻擊時，稱為分散式阻斷服務攻擊（distributed denial-of-service attack，縮寫：DDoS attack、DDoS）。據2014年統計，被確認為大規模DDoS的攻擊已達平均每小時28次。[1]DDoS發起者一般針對重要服務和知名網站進行攻擊，如銀行、信用卡支付閘道器、甚至根域名伺服器等。

DoS也常見於部分網路遊戲，被心懷不滿的玩家或是競爭對手廣泛使用。DoS也常被用於抗議，自由軟體基金會創辦人理察·斯托曼曾表示，DoS是「網路街頭抗議」的一種形式。[2]

 

當一種『攻擊』成為常態，人們不得不了解它的『機制』，尋求『防禦』方法★

DoS & DDoS attack

In this chapter, we will learn about the DoS and DdoS attack and understand how to detect them.

With the boom in the e-commerce industry, the web server is now prone to attacks and is an easy target for the hackers. Hackers usually attempt two types of attack −

  • DoS (Denial-of-Service)
  • DDoS (Distribted Denial of Service)

DoS (Denial-of-Service) Attack

The Denial of Service (DoS) attack is an attempt by hackers to make a network resource unavailable. It usually interrupts the host, temporary or indefinitely, which is connected to the Internet. These attacks typically target services hosted on mission critical web servers such as banks, credit card payment gateways.

Symptoms of DoS attack

  • Unusually slow network performance.
  • Unavailability of a particular web site.
  • Inability to access any web site.
  • Dramatic increase in the number of spam emails received.
  • Long-term denial of access to the web or any Internet services.
  • Unavailability of a particular website.

Types of DoS Attack & its Python Implementation

DoS attack can be implemented at the data link, network or application layer. Let us now learn about the different types of DoS attacks &; their implementation in Python −

Single IP single port

A large number of packets are sent to web server by using single IP and from single port number. It is a low-level attack which is used to check the behavior of the web server. Its implementation in Python can be done with the help of Scapy. The following python script will help implement Single IP single port DoS attack −

from scapy.all import *
source_IP = input("Enter IP address of Source: ")
target_IP = input("Enter IP address of Target: ")
source_port = int(input("Enter Source Port Number:"))
i = 1

while True:
   IP1 = IP(source_IP = source_IP, destination = target_IP)
   TCP1 = TCP(srcport = source_port, dstport = 80)
   pkt = IP1 / TCP1
   send(pkt, inter = .001)
   
   print ("packet sent ", i)
      i = i + 1

……

DDoS (Distributed Denial-of-Service) Attack

A Distributed Denial of Service (DDoS) attack is an attempt to make an online service or a website unavailable by overloading it with huge floods of traffic generated from multiple sources.

Unlike a Denial of Service (DoS) attack, in which one computer and one Internet connection is used to flood a targeted resource with packets, a DDoS attack uses many computers and many Internet connections, often distributed globally in what is referred to as a botnet. A large-scale volumetric DDoS attack can generate a traffic measured in tens of Gigabits (and even hundreds of Gigabits) per second. It can be read in detail athttps://www.tutorialspoint.com/ethical_hacking/ethical_hacking_ddos_attacks.htm.

Detection of DDoS using Python

Actually DDoS attack is a bit difficult to detect because you do not know the host that is sending the traffic is a fake one or real. The Python script given below will help detect the DDoS attack.

───

 

《駭客大全》上說︰

『攻防』力度強弱，實由『心智』能量驅使，一如操持

光劍

光劍[1]（英語：lightsaber）在《星際大戰》的世界觀中是一種占有舉足輕重地位的武器，在有關星戰的電影、小說或是遊戲中都經常可以見到。在星戰的世界觀中，光劍的概念即是傳統的金屬劍身被某種以純粹能量形式存在的物質所代替，而這種能量可以被凝聚成長度一米左右的劍刃形狀，並發出特定顏色的光芒。關於這種能量到底是什麼，或許是由於有些媒體的錯誤宣傳，有時人們會誤將這種構成劍身的物質簡單理解為雷射或其他光束，從而引起一些光劍是否違反物理定律之類的疑問[2]，但事實是星戰中任何地方都找不到支持劍身由光構成這一說法的證據，[3]儘管能量這一說法非常含糊。有說法解釋這種能量為一團電漿體，受到很強的磁場（或者其他種類的場）作用被束縛成劍的形狀。光劍的劍身是由其後的金屬劍柄發射出的，劍柄一般來說約長二十至三十厘米，可以根據使用者的個人需要被設計成特定的樣式。光劍開關開啟和關閉時，以及光劍揮動時都會發出特別的聲音。

「這是絕地的武器，不像雷射槍那樣笨拙難以控制。這是一種更高雅的武器，屬於那一個更文明的時代。」

歐比王·肯諾比（星際大戰四部曲：曙光乍現）

 

，至今仍是一門『藝術』也☺

The Art of Packet Crafting with Scapy

Workshop overview

  • This is an intense workshop on crafting packets using Python and Scapy.
  • We’ll understand low level networking details/abstractions like raw Sockets and move towards using high level tools like Scapy to craft packets.
  • We’ll understand Scapy framework and craft packets using it.
  • We’ll leverage Scapy as a framework to build custom network tools/utilities.

Concepts covered

  • Practical network reconnaissance techniques like host discovery, service discovery, Remote OS finger printing, promiscuous node detection using Scapy.
  • Launching Layer 2 attacks.
  • Leverage Scapy to build custom tools/utilities such as sniffers, pcap analyzer, wireless sniffers and scanners.

Skill prerequisites

  • Basics of Python programming. (strings, lists, functions, list comprehensions etc)
  • Knowledge of basic networking concepts. (Enough to know what an IP address, port number, OSI model etc.)
  • Comfortable with basic operations on your host operating system.(copying files, using text editor)