Wese munhu anoziva kuti aya matanhatu mabyte, anowanzo kuratidzwa mune hexadecimal fomati, anopihwa kunetiweki kadhi pafekitori, uye anoita seasina kurongeka. Vamwe vanhu vanoziva kuti matatu ekutanga mabheti ekero idhi rekugadzira, uye matatu asara mabhayiti anopihwa kwavari. Zvinozivikanwa zvakare kuti unogona kuzviseta zvekupokana kero. Vanhu vazhinji vakanzwa nezve "random kero" muWi-Fi.
Ngatione kuti chii.
MAC kero (media access control kero) identifier yakasarudzika inopihwa kune network adapta, inoshandiswa mumatiweki eIEEE 802 zviyero, kunyanya Ethernet, Wi-Fi uye Bluetooth. Pamutemo inonzi "EUI-48 type identifier". Kubva pazita zviri pachena kuti kero ine 48 bits kureba, i.e. 6 bytes. Hapana mwero unogamuchirwa pakunyora kero (kusiyana nekero yeIPv4, apo octets anogara akapatsanurwa nemadotsi). Inowanzonyorwa senhamba nhanhatu dzine hexadecimal dzakapatsanurwa necolon: 00:AB:CD:EF:11: 22, kunyangwe vamwe vagadziri vemidziyo vachida notation 00 -AB-CD-EF-11-22 uye kunyange 00ab.cdef.1122.
Nhoroondo, kero dzakavhenekerwa muROM yetiweki kadhi chipset pasina kugona kudzigadzirisa pasina flash programmer, asi mazuvano kero inogona kuchinjwa zvakarongwa kubva kune inoshanda sisitimu. Iwe unogona kugadzirisa nemaoko kero yeMAC yekadhi yetiweki muLinux uye MacOS (nguva dzose), Windows (inenge nguva dzose, kana mutyairi achibvumira), Android (chete midzi); Ne iOS (isina mudzi) hunyengeri hwakadaro hahugoneki.
Kero chimiro
Kero ine chikamu chechiziviso chemugadziri, OUI, uye chiziviso chakapihwa nemugadziri. Basa reOUI (Musangano Unique Identifier) zviziviso IEEE sangano. Kutaura zvazviri, kureba kwayo hakugoni kuva 3 bytes chete (24 bits), asi 28 kana 36 bits, kubva pakuvhara (MAC Address Block, MA) yemakero emhando Yakakura (MA-L), Medium (MA-M) uye Madiki anoumbwa (MA-S) zvichiteerana. Saizi yeyakaburitswa block, mune iyi kesi, ichave 24, 20, 12 bits kana 16 miriyoni, 1 miriyoni, 4 zviuru kero. Parizvino pane zviuru makumi matatu nemasere zvidhinha zvakagoverwa, zvinogona kutariswa uchishandisa akawanda maturusi epamhepo, semuenzaniso. kana .
Ndiani muridzi wemakero?
Kugadziriswa kuri nyore kwezviripo pachena IEEE inopa ruzivo rwakawanda. Semuenzaniso, mamwe masangano akazvitorera akawanda eOUI blocks. Heano magamba edu:
Mutengesi
Nhamba yemabhuroko/marekodhi
Nhamba yemakero, mamiriyoni
Cisco Systems Inc
888
14208
apuro
772
12352
Samsung
636
10144
Huawei Technologies Co.Ltd
606
9696
Intel Corporation
375
5776
Nhoroondo ye ARRIS Group Inc.
319
5104
Nhoroondo ye Nokia Corporation
241
3856
Private
232
2704
Texas Instruments
212
3392
zte corporation
198
3168
IEEE Registration Authority
194
3072
Hewlett Packard
149
2384
Hon Hai Precision
136
2176
TP LINK
134
2144
Dell Inc.
123
1968
Juniper Networks
110
1760
Sagemcom Broadband SAS
97
1552
Iyo kambani Fiberhome Telecommunication Technologies Co. LTD
97
1552
Iyo kambani Xiaomi Communications Co., Ltd
88
1408
Guangdong Oppo Mobile Telecommunications Corp.Ltd
82
1312
Google ine makumi mana chete avo, uye izvi hazvishamise: ivo pachavo havagadziri akawanda network network.
MA blocks haana kupihwa mahara, anogona kutengwa nemutengo unonzwisisika (pasina muripo wekunyorera) we3000 $, $1800 kana $755, zvichiteerana. Sezvineiwo, kune imwe mari (pagore) unogona kutenga "kuvanda" yeruzhinji ruzivo nezve yakagoverwa block. Ikozvino kune mazana maviri nemakumi matatu nemaviri avo, sezvatinoona pamusoro.
Tichapera riini kero dzeMAC?
Tese taneta nenyaya dzanga dzichiitika kwemakore gumi dzekuti "IPv10 kero dzave kupera." Hongu, matsva eIPv4 blocks haasisiri nyore kuwana. Zvinozivikanwa kuti IP kero ; Kune zvivharo zvakakura uye zvisinga shandiswe zviri pasi pemakambani makuru uye masangano ehurumende yeUS, zvisinei, vasina tariro yekuagovera kune avo vanoshaya. Kuwanda kweNAT, CG-NAT neIPv6 kwaita kuti dambudziko rekushomeka kwemakero eruzhinji riite shoma.
Kero yeMAC ine 48 bits, iyo 46 inogona kunzi "inobatsira" (sei? verenga mberi), iyo inopa 246 kana 1014 kero, iyo inopfuura 214 nguva kupfuura IPv4 kero nzvimbo.
Parizvino, inenge hafu yetrillion kero yakagoverwa, kana chete 0.73% yehuwandu hwehuwandu. Tichiri kure, kure kwazvo nekupererwa nemakero eMAC.
Randomness bits
Zvinogona kufungidzirwa kuti maOUI anogovaniswa zvisina tsarukano, uye mutengesi anozopawo zvisina tsarukano kero kune yega network zvishandiso. Ndizvo here? Ngatitarisei kugoverwa kwemabits mudhatabhesi yeMAC kero ye802.11 zvishandiso zvandiinazvo, zvakaunganidzwa nekushanda kwemvumo masisitimu mune isina waya network. . Makero ndeemidziyo chaiyo yakabatana neWi-Fi kwemakore akati wandei munyika nhatu. Mukuwedzera kune diki dhatabhesi ye802.3 wired LAN zvishandiso.
Ngatiparadzei kero yega yega yeMAC (mabhayithi matanhatu) yeimwe neimwe yemasamples kuita mabits, byte byte, uye titarise kuwanda kwekuitika kwe "1" bit mune yega yega yemakumi mana nemasere zvinzvimbo. Kana bhiti racho rakagadzirirwa zvachose, saka mukana wekuwana "48" unofanira kuva 1%.
Wi-Fi sarudzo Nhamba 1 (RF)
Wi-Fi sampuro Nhamba 2 (Belarus)
Kusarudzwa kweWi-Fi Nhamba 3 (Uzbekistan)
LAN sampling (RF)
Nhamba yezvinyorwa zviri mudhatabhesi
5929000
1274000
366000
1000
Bit number:
% zvishoma "1"
% zvishoma "1"
% zvishoma "1"
% zvishoma "1"
1
48.6%
49.2%
50.7%
28.7%
2
44.8%
49.1%
47.7%
30.7%
3
46.7%
48.3%
46.8%
35.8%
4
48.0%
48.6%
49.8%
37.1%
5
45.7%
46.9%
47.0%
32.3%
6
46.6%
46.7%
47.8%
27.1%
7
0.3%
0.3%
0.2%
0.7%
8
0.0%
0.0%
0.0%
0.0%
9
48.1%
50.6%
49.4%
38.1%
10
49.1%
50.2%
47.4%
42.7%
11
50.8%
50.0%
50.6%
42.9%
12
49.0%
48.4%
48.2%
53.7%
13
47.6%
47.0%
46.3%
48.5%
14
47.5%
47.4%
51.7%
46.8%
15
48.3%
47.5%
48.7%
46.1%
16
50.6%
50.4%
51.2%
45.3%
17
49.4%
50.4%
54.3%
38.2%
18
49.8%
50.5%
51.5%
51.9%
19
51.6%
53.3%
53.9%
42.6%
20
46.6%
46.1%
45.5%
48.4%
21
51.7%
52.9%
47.7%
48.9%
22
49.2%
49.6%
41.6%
49.8%
23
51.2%
50.9%
47.0%
41.9%
24
49.5%
50.2%
50.1%
47.5%
25
47.1%
47.3%
47.7%
44.2%
26
48.6%
48.6%
49.2%
43.9%
27
49.8%
49.0%
49.7%
48.9%
28
49.3%
49.3%
49.7%
55.1%
29
49.5%
49.4%
49.8%
49.8%
30
49.8%
49.8%
49.7%
52.1%
31
49.5%
49.7%
49.6%
46.6%
32
49.4%
49.7%
49.5%
47.5%
33
49.4%
49.8%
49.7%
48.3%
34
49.7%
50.0%
49.6%
44.9%
35
49.9%
50.0%
50.0%
50.6%
36
49.9%
49.9%
49.8%
49.1%
37
49.8%
50.0%
49.9%
51.4%
38
50.0%
50.0%
49.8%
51.8%
39
49.9%
50.0%
49.9%
55.7%
40
50.0%
50.0%
50.0%
49.5%
41
49.9%
50.0%
49.9%
52.2%
42
50.0%
50.0%
50.0%
53.9%
43
50.1%
50.0%
50.3%
56.1%
44
50.1%
50.0%
50.1%
45.8%
45
50.0%
50.0%
50.1%
50.1%
46
50.0%
50.0%
50.1%
49.5%
47
49.2%
49.4%
49.7%
45.2%
48
49.9%
50.1%
50.7%
54.6%
Sei kusaruramisira kwakadaro mu7 uye 8 bits? Kune anenge nguva dzose mazero.
Chokwadi, chiyero chinotsanangura mabhiti aya seakakosha ():
Yechisere (kubva pakutanga) bhiti rekutanga byte yeMAC kero inodaidzwa kuti Unicast/Multicast bit uye inosarudza rudzi rwefuremu (frame) inofambiswa nekero iyi, yakajairwa (0) kana kutepfenyura (1) (multicast kana nhepfenyuro). Kune zvakajairwa, unicast network adapter kutaurirana, iyi bhiti yakaiswa ku "0" mumapaketi ese anotumirwa kwairi.
Yechinomwe (kubva pakutanga) bhiti rekutanga byte yekero yeMAC inodaidzwa kuti U/L (Universal/Local) bit uye inosarudza kana kero yacho yakasiyana nepasi rose (0), kana kuti yakasarudzika munharaunda (1). Nekumisikidza, ese "mugadziri-akasona" kero akasiyana epasirese, saka iyo yakawanda yakaunganidzwa kero yeMAC ine yechinomwe yakaiswa ku "0". Mutafura yezviziviso zveOUI, vanongopinda zana nemakumi matatu chete vane U/L bit ye “130”, uye sezviri pachena aya mabhuraki emakero eMAC kune zvakakosha.
Kubva pachitanhatu kusvika kune ekutanga mabheti ebhaiti yekutanga, mabheti echipiri neechitatu mabhayithi mune zviziviso zveOUI, uye zvakatonyanya mabheti ari mu4-6 byte yekero yakapihwa nemugadziri anogovaniswa zvakanyanya kana zvishoma zvakaenzana. .
Saka, mune chaiyo MAC kero ye network adapta, mabheti acho akaenzana uye haana chirevo chetekinoroji, kunze kwemabhiti maviri ebasa reiyo yakakwira byte.
Kuwanda
Kunetseka kuti ndevapi vanogadzira michina isina waya vanonyanya kufarirwa? Ngatisanganise kutsvaga mudura reOUI nedata kubva kumuenzaniso Nha.
Mutengesi
Kugoverwa kwemidziyo, %
apuro
26,09
Samsung
19,79
Huawei Technologies Co Ltd
7,80
Iyo kambani Xiaomi Communications Co., Ltd
6,83
Iyo kambani Sony Mobile Communications Inc
3,29
LG Electronics (Mobile Communications)
2,76
ASUSTek Komputa INC.
2,58
Nhoroondo ye TCT Mobile Ltd
2,13
zte corporation
2,00
haina kuwanikwa muIEEE dhatabhesi
1,92
Lenovo Mobile Communication Technology Ltd.
1,71
HTC CORP
1,68
Murata Manufacturing
1,31
InPro Comm
1,26
Microsoft Corporation
1,11
Shenzhen TINNO Mobile Technology Corp.
1,02
Motorola (Wuhan) Mobility Technologies Communication Co. Ltd.
0,93
Nhoroondo ye Nokia Corporation
0,88
Iyo kambani Shanghai Wind Technologies Co. Ltd
0,74
Lenovo Mobile Communication (Wuhan) Company Limited
0,71
Kudzidzira kunoratidza kuti zvakanyanya kubudirira kukwikwidza kwevasina waya kunetiweki vanyoreri munzvimbo yakapihwa, kunowedzera kugovaniswa kweApple zvishandiso.
Yakasiyana
Makero eMAC akasiyana here? Mune dzidziso, hongu, sezvo yega yega inogadzira mudziyo (MA block muridzi) inodiwa kuti ipe yakasarudzika kero kune yega yega network adapter yainoburitsa. Nekudaro, vamwe vanogadzira chip, vanoti:
- 00:0A:F5 Airgo Networks, Inc. (ikozvino Qualcomm)
- 00:08:22 InPro Comm (ikozvino MediaTek)
isa mabheti matatu ekupedzisira ekero yeMAC kunhamba isina kurongeka, sezviri pachena mushure mekutangazve mudziyo wega wega. Paive ne1 zviuru zvekero dzakadaro mumuenzaniso wangu Nha.
Iwe unogona, hongu, kuzvimisira kero yekune imwe nyika, isiri-yakasarudzika nekuimisa nemaune "seyemuvakidzani wako", uchiizivisa nemufeki, kana kuisarudza chero. Izvo zvakare zvinogoneka kuti uzviise netsaona kero isiri-yakasarudzika ne, semuenzaniso, kudzoreredza gadziriro yekuchengetedza ye router seMikrotik kana OpenWrt.
Chii chichaitika kana paine zvishandiso zviviri panetiweki zvine kero imwechete yeMAC? Izvo zvese zvinoenderana nepfungwa yetiweki zvishandiso (wired router, wireless network controller). Zvingangodaro, zvese zvishandiso zvingave zvisingashande kana kuti zvichashanda nepakati. Kubva pakuona kweIEEE zviyero, dziviriro kubva kuMAC kero spoofing inokurudzirwa kugadziriswa uchishandisa, semuenzaniso, MACsec kana 802.1X.
Ko kana ukaisa MAC ine yechinomwe kana yechisere yakaiswa ku "1", i.e. kero yemuno kana yakawanda? Zvingangodaro, network yako haizotarisi kune izvi, asi zviri pamutemo kero yakadaro haizoenderana neyakajairwa, uye zviri nani kuti usadaro.
Kuti randomisation inoshanda sei
Isu tinoziva kuti kudzivirira kuteedzera mafambiro evanhu nekutarisa uye kuunganidza airwaves, smartphone MAC masisitimu anoshanda anga achishandisa randomisation tekinoroji kwemakore akati wandei. Sezvineiwo, kana uchitarisa mafungu emhepo uchitsvaga anozivikanwa network, iyo smartphone inotumira pakiti (boka remapakiti) ye802.11 probe chikumbiro mhando ine MAC kero sesosi:
Inogoneswa randomization inokutendera kuti utaure kwete iyo "yakasonwa" imwe, asi imwe kero yepaketi sosi, ichichinja nekutenderera kwega kwega, nekufamba kwenguva, kana neimwe nzira. Inoshanda here? Ngatitarisei huwandu hwekero dzeMAC dzakaunganidzwa kubva kumhepo neinonzi "Wi-Fi Radar":
Muenzaniso wose
Sample chete ne zero 7th bit
Nhamba yezvinyorwa zviri mudhatabhesi
3920000
305000
Bit number:
% zvishoma "1"
% zvishoma "1"
1
66.1%
43.3%
2
66.5%
43.4%
3
31.7%
43.8%
4
66.6%
46.4%
5
66.7%
45.7%
6
31.9%
46.4%
7
92.2%
0.0%
8
0.0%
0.0%
9
67.2%
47.5%
10
32.3%
45.6%
11
66.9%
45.3%
12
32.3%
46.8%
13
32.6%
50.1%
14
33.0%
56.1%
15
32.5%
45.0%
16
67.2%
48.3%
17
33.2%
56.9%
18
33.3%
56.8%
19
33.3%
56.3%
20
66.8%
43.2%
21
67.0%
46.4%
22
32.6%
50.1%
23
32.9%
51.2%
24
67.6%
52.2%
25
49.8%
47.8%
26
50.0%
50.0%
27
50.0%
50.2%
28
50.0%
49.8%
29
50.0%
49.4%
30
50.0%
50.0%
31
50.0%
49.7%
32
50.0%
49.9%
33
50.0%
49.7%
34
50.0%
49.6%
35
50.0%
50.1%
36
50.0%
49.5%
37
50.0%
49.9%
38
50.0%
49.8%
39
50.0%
49.9%
40
50.0%
50.1%
41
50.0%
50.2%
42
50.0%
50.2%
43
50.0%
50.1%
44
50.0%
50.1%
45
50.0%
50.0%
46
50.0%
49.8%
47
50.0%
49.8%
48
50.1%
50.9%
Mufananidzo wacho wakasiyana zvachose.
Iyo yechisere yebhayiti yekutanga yekero yeMAC ichiri kuenderana neiyo Unicast chimiro cheiyo SRC kero mupaketi yekukumbira probe.
Iyo 7th bit yakaiswa kuLocal mu92.2% yemakesi, i.e. Nekuvimba kwakaringana, tinogona kufunga kuti chaizvo akawanda emakero akaunganidzwa akasarudzika, uye asingasviki 8% ndeyechokwadi. Muchiitiko ichi, kugoverwa kwemabits muOUI yemakero chaiwo akadai anowirirana nedata riri patafura yapfuura.
Ndeupi mugadziri, maererano neOUI, ane makero asina kujairika (kureva ane 7th bit mu "1")?
Mugadziri neOUI
Goverana pakati pemakero ese
haina kuwanikwa muIEEE dhatabhesi
62.45%
Google Inc.
37.54%
zorora
0.01%
Uyezve, kero dzese dzisina kurongeka dzakapihwa kuGoogle ndedzeOUI imwechete ine prefix DA:A1:19. Chivakamberi ichi chii? Ngatitarisei mukati .
private static final MacAddress BASE_GOOGLE_MAC = MacAddress.fromString("da:a1:19:0:0:0");Stock Android inoshandisa yakakosha, yakanyoreswa OUI kana uchitsvaga isina waya network, imwe yevashoma ine yechinomwe seti.
Verenga chaiyo MAC kubva kune yakasarudzika imwe
Ngationei ipapo:
private static final long VALID_LONG_MASK = (1L << 48) - 1;
private static final long LOCALLY_ASSIGNED_MASK = MacAddress.fromString("2:0:0:0:0:0").mAddr;
private static final long MULTICAST_MASK = MacAddress.fromString("1:0:0:0:0:0").mAddr;
public static @NonNull MacAddress createRandomUnicastAddress(MacAddress base, Random r) {
long addr;
if (base == null) {
addr = r.nextLong() & VALID_LONG_MASK;
} else {
addr = (base.mAddr & OUI_MASK) | (NIC_MASK & r.nextLong());
}
addr |= LOCALLY_ASSIGNED_MASK;
addr &= ~MULTICAST_MASK;
MacAddress mac = new MacAddress(addr);
if (mac.equals(DEFAULT_MAC_ADDRESS)) {
return createRandomUnicastAddress(base, r);
}
return mac;
}
Kero yese, kana mabhayiti ayo ezasi matatu, akachena Random.nextLong(). "Proprietary recovery yeMAC chaiyo" itsotsi. Nekuvimba kwakanyanya, tinogona kutarisira kuti vagadziri vemafoni eAndroid vanoshandisa mamwe, asina kunyoreswa maOUI. Isu hatina iyo iOS sosi kodhi, asi kazhinji algorithm yakafanana inoshandiswa ipapo.
Izvo zviri pamusoro hazvikanzure basa redzimwe nzira dzekudzima-mazita vanyoreri veWi-Fi, zvichibva pakuongororwa kwemamwe matunhu eiyo probe chikumbiro furemu, kana kuwirirana kwehuwandu hwehuwandu hwezvikumbiro zvinotumirwa nemudziyo. Nekudaro, kuteedzera munyoreri nekuvimbika uchishandisa nzira dzekunze kune dambudziko. Iyo data yakaunganidzwa ichave yakakodzera yekuongorora avhareji / peak mutoro nenzvimbo uye nguva, zvichibva pahuwandu hukuru, pasina kutaurwa kune chaiyo michina uye vanhu. Avo chete "mukati", ivo vanogadzira mbozha OS ivo pachavo, uye maapplication akaiswa ane data chaiyo.
Chii chingave chine njodzi kune mumwe munhu kuziva kero yeMAC yemudziyo wako? Kuramba kurwiswa kwesevhisi kunogona kutangwa kune waya uye isina waya network. Kune mudziyo usina waya, uyezve, neimwe mukana zvinokwanisika kurekodha nguva yekuonekwa kwayo munzvimbo iyo sensor yakaiswa. Nekubira kero, unogona kuedza "kunyepedzera" kunge mudziyo wako, unogona kushanda chete kana pasina mamwe matanho ekuchengetedza anoshandiswa (mvumo uye / kana encryption). 99.9% yevanhu pano havana chekunetseka nazvo.
Iyo MAC kero yakanyanya kuoma kupfuura zvinoita, asi iri nyore kupfuura zvazvingave.
Source: www.habr.com