Dabarun ‘Yan Dandatsa da Hanyoyin Dakile Su (5)

Darasi Na (02): “Scanning Networks”

Bayan darasi kan yadda ake tattaro bayanai kan kwamfuta ko kamfani ko wata na’urar da ake son isa gare ta, a darasi na biyu mai take: “Scanning Networks,” ana karantar da dalibai ne yadda zasu yi amfani da bayanan da suka samo daga wancan bincike, wajen isa ga wata kwamfuta ko na’ura ta musamman da suka samo adireshi ko sunanta.  Kafin nan, zai dace mai karatu ya fahimci cewa, duk wata kwamfuta da kake iya isa gareta a tsarin sadarwa na zamani, tana ajiye ne a wani zangon sadarwa na musamman, dake wani wuri na musamman, a wata kasa ko jiha ko gari na musamman, cikin ginin wani kamfani ko ofishi ko gida ko daki na musamman.  Wannan zango shi ake kira: “Local Area Network” (LAN), wanda munyi darasi kan shi a kasidarmu mai take: “Tsarin Sadarwa Tsakanin Kwamfutoci,” a shekarun baya.

Wannan zango mai suna LAN a gajarce, yana dauke ne da kwamfutoci da aka hada alaka a tsakaninsu.  Misali, hokumomin gwamnati da wasu kamfanoni masu zaman kansu suna da kwamfutoci da suke amfani dasu a ma’aikatansu.  Wadannan kwamfutoci an hada su da juna ne, ta yadda za ka iya isa wata kwamfutar daga kwamfutar da kake aiki a kai, muddin an baka iznin yin hakan.  Daga cikin wadannan kwamfutoci, duk kwamfutar dake jone da Intanet, a matsayin Uwar Garke (Web Server), idan aka gudanar da bincike mai kyau ana iya samun lambarta, wato: “IP Address”.  Idan anyi sa’a  ma har da sunanta (Host Name), da sunayen ma’aikatan dake hukumar (Username), da lambobin wasu kwamfutocin dake zangon baki daya.  Wanda shi ne tsarin da darasin baya ke karantarwa.  Da zarar ka iya samun wadannan bayanai, sai matakin tantance kwamfutocin ta hanyar bayanan da ka samu a matakin farko.  Wannan shi ake kira: “Scanning Networks.”

Manufa da Tsari

Babbar manufar wannan mataki shi ne: “Tantance kwamfutoci da na’urorin sadarwar dake wani zango na sadarwa, don tabbatar da masu rai daga cikinsu, da abubuwan da suke dauke dasu.”

A wannan mataki dai za a karantar da dalibi ne yadda zai kwankwasa kofar wani zangon sadarwa, don sanin wadanda ke cikin zangon, da bayanan da suke dauke dasu, don sanin hanyar da zai bi don daukowa ko nadewa ko saukar da duk abin da yake bukata.  Hakan na yiwuwa ne ta hanyar shigar da lambar kwamfutar (IP Address, misali: 192.168.115.12) a kan wata manhaja ta musamman da aka tanada, don nemo bayanan da suka shafeta.

Daga cikin bayanan kuwa akwai nau’in babbar manhaja (Operating System), da zubinta (Version), da kafofin sadarwar da kwamfutar ke dauke dasu, wato: “Ports” da manhajojin sadarwar dake dauke a kowace kafar sadarwa.  Misali, a kafar sadarwa mai lamba ta: 25 ne ake samun manhajar sadarwar Imel, wato: “Simple Mail Transfer Protocol” (SMTP).  A kafar sadarwa mai lamba ta 80 kuma ake samun manhajar ka’idar sadarwa ta Intanet, wadda da it ace kwamfuta ke iya sadar da keg a Intanet, wato: “Hypertext Transfer Protocol” (HTTP).

Bayan haka, ta wannan hanya ne za a sanar da dalibi yadda zai gane ko wadancan kafafe na sadarwa a kunne suke ko a kashe suke.  Sannan ta haka zai iya gane wasu manhajoji ne a kunne a kafar.  Wadannan kananan manhajoji su ake kira: “Services.”  Sannan idan kafafen a toshe suke, akwai yadda za ka iya gane dabarun da aka yi amfani dasu wajen toshe su.  Sannan idan zangon sadarwa na dauke da wasu manhajojin  tsaro da aka sa, irin su: “Intrusion Detection System” (IDS), ko “Intrusion Prevention Sysmte” (IPS), ko “Firewall” (Garkuwar wuta), duk za ka iya ganewa.  A karshe kuma a koya maka yadda za ka iya waske wadannan hanyoyin tsaro cikin sauki.

Nau’ukan Hanyoyin Tantancewa

Tsarin haka alaka tsakanin kwamfutoci ya kasu kashi biyu ne: akwai tsari na kai tsaye wanda ke amfani da lambar IP.  Wannan shi ake kira: “IP/TCP Connection.”  Wannan tsarin ya fi aminci, wajen tabbatar da samuwar alaka tsakanin kwamfutoci wajen aika sakonni a tsakaninsu.  Komai a bayyane yake.  Tsari na biyu shi ake kira: “UDP Connection.”  A wannan tsari, wanda yana amfani ne da tsarin wayar-iska (wato: “Connectionless system”), ba ka iya gane isar sakonni tsakanin kwamfutoci, sun isa ko basu isa ba?  A tsarin farko, idan ka aika sako zuwa ga wata kwamfuta, idan a kashe take, nan take za a dawo maka da sakonka, kai tsaye.  Amma a tsari na biyu, muddin sakon bai je ba, sai dai kaji shiru.

Karkashin wannan darasi za a koya maka yadda za iya nemo kwamfuta ta wadannan hanyoyi guda biyu.  Tsarin iya magana da kwamfuta dai shi ake kira: “Three way handshake.”  Tsarin nemo kwamfuta ta hanyar “IP/TCP Connection” ya kunshi hanyoyi masu yawa, saboda ingancinsa.  Duk za a karantar daku wadannan hanyoyi, wadanda suka hada da: “TCP Connect” ko “Full Open Scan”, da “Half-open Scan”, da “Inverse TCP Flag Scanning,” da ACK Flag Probe Scanning” da kuma “IDLE/IP ID Header Scanning.”  Shi tsarin “Inverse TCP Flag Scanning” ya kasu kashi uku.  Akwai “Xmas Scan,” da “FIN Scan,” da kuma “NULL Scan.”  A nasa bangaren, tsarin “UDP Scanning” wanda nace ba shi da tabbas, tsari ne guda.  Kuma ana amfani dashi ne a wasu lokuta idan abubuwa suka rikice.  Wadannan duka hanyoyi ne da ake amfani dasu wajen daburtar da kwamfuta yayin mika mata umarni, don ta maido irin jawaban da ake so ta maido, ko ba ta so.

Manhajoji na Musamman

Gudanar da wannan aiki na yiwuwa ne ta hanyar manhajoji na musamman.  Akwai babbar manhajar kwamfuta ta musamman da aka gina ta dauke da galibin wadannan manhajoji.  Wannan babbar manhaja dai ta asalin Linux ce, ana kiranta: “Kali Linux.”  Tsohon sunan da ta shahara dashi a baya shi ne: “Backtrack.”  Wannan babbar manhajar kyauta ake samunta. Haka idan kana da babbar manhajar Linux nau’in “Ubuntu,” kana iya loda mata dukkan manhajojin dake dauke kan “Kali Linux” cikin sauki.  Idan kuma babbar manhajar “Windows” kake amfani da ita, akwai manhajoji daidaiku na musamman da za ka saukar don gudanar da wannan aiki cikin sauki.

Shahararriya cikin jerin wadannan manhajoji dai ita ce: “Nmap” (http://nmap.org), wanda babba kuma kwararre a fannin kwamfuta da sadarwa, Mr. Gordon Lyon ya gina a shekarar 1997, shekaru 20 kenan da suka wuce.  Wannan manhaja ita ce uwa a fannin zakulo bayanai kan kowace irin kwamfuta ne da bayanan da take dauke dasu a duniyar sadarwa.  Manhajar nau’i biyu ce: akwai wacce ake amfani da ita ta karkashin kasa (Command Line Interface version), da kuma wadda za ka iya amfani da kai tsaye (GUI Version).  Manhajar “nmap” ba ta da na biyu a wannan fanni.

Wasu daga cikin manhajojin sun hada da: “SuperScan” (http://mcafee.com) na kamfanin McAfee dake kasar Amurka.  Sauran sun hada da “PRTG Network Monitor” (http://paessler.com) mai taimaka maka gano bayanai kan wani zangon sadarwa na musamman da abubuwan dake dauka cikinsa.  Da manhajar “Network Inventory Explorer” (http://10-strike.com), da “Global Network Inventory Scanner” (http://magnetsoft.com), da manhajar “Net Tools” (http://mabsoft.com), da “IP Tools” (http://ks-soft.net), da “Advanced Port Scanner” (http://radmin.com) da kuma “MegaPing” dake shafin http://magnetsoft.com.  Wadannan duk kana iya saukar dasu kan kwamfutarka kyauta, ko kayi amfani da wasunsu a kan shafinsu da ke Intanet, don gudanar da bincikenka.

Akwai kuma wasu manhajoji na musamman da aka gina don amfani dasu kan wayar salula.  Daga cikinsu akwai: “IP Network Scanner” da “Fing” da “Umit Network Scanner” da kuma “PortDroid Network Analysis.”

Wadannan kadan ne daga cikin jerin manhajojin da “Hackers” ke amfani dasu wajen tattaro bayanai kan kwamfutocin dake wani zangon sadarwa da sauran na’urorin sadarwa makamantansu, don sanin hanyar riskarsu kai tsaye, ba tare da wani bata lokaci ba.  Karkashin wannan darasi na biyu duk za a karantar da dalibi dabarun da ake amfani da wadannan manhajoji, da kuma yadda zai kare kamfani ko kwamfutar da aka bashi amanar karewa cikin sauki.

Hanyoyin Kariya

Duk da cewa duk kwamfutar din dake jone da Intanet a ko ina take a duniya, ana iya riskar bayanan da suka shafeta ta wannan hanya, tare da kokarin kaiwa gareta cikin sauki, akwai hanyoyi da na musamman da ake iya bata kariya.  Za a koyar da dalibi yadda ake kintsa kwamfuta ta yadda idan an kutso cikin zangon sadarwar da kwamfutar ke dauke, za a bata kariya.  Sannan da yadda ake tsara manhajar baiwa kwamfuta kariya, wato: “Intrusion Detection System” da “Intrusion Prevention System,” don tabbatar da cewa duk wata manhaja da za ta kutso cikin zangon sadarwar, an tsare.

A darasi na gaba cikin makon gobe in Allah Ya yarda, za mu kawo bayani kan darasi na uku, wato: “Enumeration,” darasin dake dauke da bayanai kan dabarun da ake bi wajen isa ga hakikanin kafofin sadarwar dake kwamfuta.