features免费dns
免费dns 时间:2021-04-20 阅读:()
IntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBPassiveDNSHardeningRobertEdmondsInternetSystemsConsortium,Inc.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEStructureofthistalkIntroductionDNSPassiveDNSISCSIEDNSsecurityissuesKashpurepoisoningKaminskypoisoningPassiveDNSsecurityissuesRecordinjectionResponsespoongISCDNSDBArchitectureDemosRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIETheDomainNameSystem"TheDNSmapshostnamestoIPaddresses.
"Moregenerally,itmaps(key,type)tuplestoasetofunorderedvalues.
again,wecanthinkoftheDNSasbasicallyamulti-valuedistributedkey-valuestore.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEClients,caches,contentClientsrequestfullresolutionservicefromcaches.
CachesmakezeroormoreinquiriestoDNScontentserversonbehalfofclients.
Resultsarecachedforalimitedtimetoservefutureclientrequests.
ContentnameserversserveDNSrecordsforzonesthathavebeendelegatedtothem.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIERobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEClient-serverandinter-serverDNSprotocolsTheDNSisactuallytwodierentprotocolsthatshareacommonwireformat.
Theclient-to-serverprotocolspokenbetweenclientsandcaches.
Theinter-serverprotocolspokenbetweencachesandcontentservers.
PassiveDNSfocusesonthelatter.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEPassiveDNSPassiveDNSreplicationisatechnologyinventedin2004byFlorianWeimer.
Manyuses!
Malware,e-crime,legitimateInternetservicesallusetheDNS.
Inter-serverDNSmessagesarecapturedbysensorsandforwardedtoacollectionpointforanalysis.
Afterbeingprocessed,individualDNSrecordsarestoredinadatabase.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIERobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEPassiveDNSdeploymentsFlorianWeimer'soriginaldnslogger,rstatRUS-CERT,thenatBFK.
de(2004–).
BojanZdrnja'sdnsparse(2006–).
ISC'sSecurityInformationExchange(2007–).
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEISCSecurityInformationExchangeSIEisadistributionnetworkfordierenttypesofsecuritydata.
OneofthosetypesofdataispassiveDNS.
SensoroperatorsuploadbatchesofdatatoSIE.
DataisbroadcastontoprivateVLANs.
NMSGformatisusedtoencapsulatedata.
HasanumberoffeatureswhichmakeitveryusefulforstoringpassiveDNSdata,butwon'tbecoveredfurther.
SeeourGoogleTechTalkformoreinformation:http://www.
isc.
org/community/presentations/video.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningDNSSecurityIssuesPassiveDNScapturesbothsignedandunsigneddata,soDNSSECcannothelpus.
WhatsecurityissuesarethereintheDNSthatarerelevanttopassiveDNSKashpurepoisoningKaminskypoisoning(Actually,justresponsespoongingeneral.
)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningKashpurepoisoningisthenamegiventoaparticulartypeofDNScachepoisoning.
Theattackerrunsacontentnameserver.
Aclientisenticedtolookupadomainnameundertheattacker'scontrol.
Thecachecontactstheattacker'snameserver.
Theattacker'snameserverprovidesextrarecordstothecache.
Theextrarecordsareinsertedintothecacheinsteadofbeingdiscarded.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningexampleQ:malicious.
example.
com.
INAR:malicious.
example.
com.
INNSwww.
example.
net.
R:www.
example.
net.
INA203.
0.
113.
67RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningexampleQ:malicious.
example.
com.
INAR:malicious.
example.
com.
INNSwww.
example.
net.
R:www.
example.
net.
INA203.
0.
113.
67RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningexampleQ:malicious.
example.
com.
INAR:malicious.
example.
com.
INNSwww.
example.
net.
R:www.
example.
net.
INA203.
0.
113.
67RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurehardening1997:EugeneKashpurehijackstheInterNICwebsite.
BIND4.
9.
6and8.
1.
1introducehardeningagainstKashpurepoisoning.
RFC2181ispublished.
See§5.
4.
1"Rankingdata"fordetails.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningLackofentropy2000:DJBobservesthatamaximumofonlyabout31-32bitsofentropycanprotectaUDPDNSquery.
OtherDNSimplementationsslowtoadoptSPR.
32bitsofentropyparticularlyweakforasessionIDduetothebirthdayattackproblem.
NewerprotocolsusecryptographicallysecuresessionIDswith64,128,ormorebits.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKaminskypoisoning2008:DanKaminskynoticesthattheTTLcanbebypassed.
Coordinated,multi-vendorpatchesarereleasedtoimplementsourceportrandomization.
SPRmakesKaminskyattacksharder,butnotimpossible.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstageRelevancetopassiveDNSWeimer's2005papernotesseveralproblemswithverifyingpassiveDNSdata.
KashpureandKaminskypoisoningof"activeDNS"haveanaloguesinpassiveDNS.
PassiveDNSsensorscan'tseetheDNScache's"bailiwick",leadingtorecordinjection.
Spoofedresponsesaretreatedjustlikenormalresponses.
AsinglespoofedresponsecanpoisonthepassiveDNSdatabase!
Goal:makepassiveDNSatleastasreliableasactiveDNS.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstageProtectingthecapturestageagainstresponsespoongCapturebothqueriesandresponses.
Correlateresponseswithpreviouslyseenqueries.
TheDNSmessage9-tuple:1.
InitiatorIPaddress2.
Initiatorport3.
TargetIPaddress4.
Targetport5.
Internetprotocol6.
DNSID7.
Queryname8.
Querytype9.
QueryclassRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagenmsg/dnsqrdnsqrisamessagemoduleforISC'slibnmsgspecicallydesignedforpassiveDNScapture.
UDPDNStransactionsareclassiedintothreecategories:1.
UDPQUERYRESPONSE2.
UDPUNANSWEREDQUERY3.
UDPUNSOLICITEDRESPONSEPerformsIPreassembly,too!
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstageProtectingtheanalysisstageagainstrecordinjectionCachesinternallyassociatea"bailiwick"witheachoutgoingquery.
Thecacheknowswhatbailiwicktouse,becauseitknowswhyit'ssendingaparticularquery.
Wehavetocalculatethebailiwickourselves.
Protectionagainstrecordinjectionrequiresprotectionagainstspoofedresponses.
(Otherwise,anattackercouldjustspooftherecordandthesourceIPaddressofanin-bailiwicknameserver.
)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmMustoperatecompletelypassively.
Mustprovideabooleantrueorfalseforeachrecord.
"Foreachrecordname,istheresponseIPaddressanameserverforthezonethatcontainsorcancontainthisname"Example:rootnameserverscanassertknowledgeaboutanyname!
Example:Verisign'sgtldserverscanassertknowledgeaboutanydomainnameendingin.
comor.
net.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmInitializebailiwickcachewithacopyoftherootzone.
CachestartsowithknowledgeofwhichserversservetherootandTLDs.
Findallpotentialzonesthatanamecouldbelocatedin.
Checkwhetheranyofthenameserversforthosezonesarethenameserverthatsenttheresponse.
EachtimeanNS,A,orAAAArecordisveriedbythealgorithm,itisinsertedintothebailiwickcache.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexampleName:example.
com.
Server:192.
5.
6.
30Potentialzones:example.
com.
com.
.
Zonesinbailiwickcache:com.
.
Check:example.
com.
/NSNotfound.
Check:com.
/NSFound13nameservers.
Check:areanyofthem192.
5.
6.
30Yes.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexamplecom.
INNSa.
gtldservers.
net.
a.
gtldservers.
net.
INA192.
5.
6.
30RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexample;;QUESTIONSECTION:;www.
example.
com.
INA;;AUTHORITYSECTION:example.
com.
172800INNSa.
ianaservers.
net.
example.
com.
172800INNSb.
ianaservers.
net.
;;ADDITIONALSECTION:a.
ianaservers.
net.
172800INA192.
0.
34.
43b.
ianaservers.
net.
172800INA193.
0.
0.
236;;SERVER:192.
5.
6.
30#53(192.
5.
6.
30)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexample;;QUESTIONSECTION:;www.
example.
com.
INA;;ANSWERSECTION:www.
example.
com.
172800INA192.
0.
32.
10;;AUTHORITYSECTION:example.
com.
172800INNSa.
ianaservers.
net.
example.
com.
172800INNSb.
ianaservers.
net.
;;SERVER:192.
0.
34.
43#53(192.
0.
34.
43)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexampleName:www.
example.
com.
Server:192.
0.
34.
43Potentialzones:www.
example.
com.
example.
com.
com.
.
Zonesinbailiwickcache:example.
com.
com.
.
Check:www.
example.
com.
/NSNotfound.
Check:example.
com.
/NSFound2nameservers.
Check:areanyofthem192.
0.
34.
43Yes.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesDNSDBDNSDBisadatabaseforstoringDNSrecords.
DataisloadedfrompassiveDNSandzoneles.
IndividualDNSrecordsarestoredinanApacheCassandradatabase.
Oerskey-valuestoredistributedacrossmultiplemachines.
GoodtforDNSdata.
Sustainsextremelyhighwritethroughputbecauseallwritesaresequential.
OersaRESTfulHTTPAPIandwebsearchinterface.
Databasecurrentlyconsumesabout500GBoutof27TB.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesArchitectureComponentsDatasourcesnmsg-dns-cacheDNSTLDzones(FTPviaZFAprograms):com,net,org,etc.
DNSzones(standardAXFR/IXFRprotocol)DataloadersDeduplicatedpassiveDNSZoneledataRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesDatasource:nmsg-dns-cacheReadsrawDNSresponsesfrompassiveDNS.
ParseseachDNSmessageintoindividualDNSRRsets.
Seriesofltersreducethetotalamountofdatabyabout50%.
RRsetsaretheninsertedintoanin-memorycache.
CacheisexpiredinFIFOorder.
WhenRRsetsexpirefromthecache,theyformthenalnmsg-dns-cacheoutput.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesDatasource:zonelesgTLDZoneFileAccessprograms:com,net,org,info,biz,nameAXFR'dzones:isc.
org,afewother"test"zones.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesExample#1:*.
google.
comRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardening
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEStructureofthistalkIntroductionDNSPassiveDNSISCSIEDNSsecurityissuesKashpurepoisoningKaminskypoisoningPassiveDNSsecurityissuesRecordinjectionResponsespoongISCDNSDBArchitectureDemosRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIETheDomainNameSystem"TheDNSmapshostnamestoIPaddresses.
"Moregenerally,itmaps(key,type)tuplestoasetofunorderedvalues.
again,wecanthinkoftheDNSasbasicallyamulti-valuedistributedkey-valuestore.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEClients,caches,contentClientsrequestfullresolutionservicefromcaches.
CachesmakezeroormoreinquiriestoDNScontentserversonbehalfofclients.
Resultsarecachedforalimitedtimetoservefutureclientrequests.
ContentnameserversserveDNSrecordsforzonesthathavebeendelegatedtothem.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIERobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEClient-serverandinter-serverDNSprotocolsTheDNSisactuallytwodierentprotocolsthatshareacommonwireformat.
Theclient-to-serverprotocolspokenbetweenclientsandcaches.
Theinter-serverprotocolspokenbetweencachesandcontentservers.
PassiveDNSfocusesonthelatter.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEPassiveDNSPassiveDNSreplicationisatechnologyinventedin2004byFlorianWeimer.
Manyuses!
Malware,e-crime,legitimateInternetservicesallusetheDNS.
Inter-serverDNSmessagesarecapturedbysensorsandforwardedtoacollectionpointforanalysis.
Afterbeingprocessed,individualDNSrecordsarestoredinadatabase.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIERobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEPassiveDNSdeploymentsFlorianWeimer'soriginaldnslogger,rstatRUS-CERT,thenatBFK.
de(2004–).
BojanZdrnja'sdnsparse(2006–).
ISC'sSecurityInformationExchange(2007–).
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBDNSPassiveDNSISCSIEISCSecurityInformationExchangeSIEisadistributionnetworkfordierenttypesofsecuritydata.
OneofthosetypesofdataispassiveDNS.
SensoroperatorsuploadbatchesofdatatoSIE.
DataisbroadcastontoprivateVLANs.
NMSGformatisusedtoencapsulatedata.
HasanumberoffeatureswhichmakeitveryusefulforstoringpassiveDNSdata,butwon'tbecoveredfurther.
SeeourGoogleTechTalkformoreinformation:http://www.
isc.
org/community/presentations/video.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningDNSSecurityIssuesPassiveDNScapturesbothsignedandunsigneddata,soDNSSECcannothelpus.
WhatsecurityissuesarethereintheDNSthatarerelevanttopassiveDNSKashpurepoisoningKaminskypoisoning(Actually,justresponsespoongingeneral.
)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningKashpurepoisoningisthenamegiventoaparticulartypeofDNScachepoisoning.
Theattackerrunsacontentnameserver.
Aclientisenticedtolookupadomainnameundertheattacker'scontrol.
Thecachecontactstheattacker'snameserver.
Theattacker'snameserverprovidesextrarecordstothecache.
Theextrarecordsareinsertedintothecacheinsteadofbeingdiscarded.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningexampleQ:malicious.
example.
com.
INAR:malicious.
example.
com.
INNSwww.
example.
net.
R:www.
example.
net.
INA203.
0.
113.
67RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningexampleQ:malicious.
example.
com.
INAR:malicious.
example.
com.
INNSwww.
example.
net.
R:www.
example.
net.
INA203.
0.
113.
67RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurepoisoningexampleQ:malicious.
example.
com.
INAR:malicious.
example.
com.
INNSwww.
example.
net.
R:www.
example.
net.
INA203.
0.
113.
67RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKashpurehardening1997:EugeneKashpurehijackstheInterNICwebsite.
BIND4.
9.
6and8.
1.
1introducehardeningagainstKashpurepoisoning.
RFC2181ispublished.
See§5.
4.
1"Rankingdata"fordetails.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningLackofentropy2000:DJBobservesthatamaximumofonlyabout31-32bitsofentropycanprotectaUDPDNSquery.
OtherDNSimplementationsslowtoadoptSPR.
32bitsofentropyparticularlyweakforasessionIDduetothebirthdayattackproblem.
NewerprotocolsusecryptographicallysecuresessionIDswith64,128,ormorebits.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBKashpurepoisoningKaminskypoisoningKaminskypoisoning2008:DanKaminskynoticesthattheTTLcanbebypassed.
Coordinated,multi-vendorpatchesarereleasedtoimplementsourceportrandomization.
SPRmakesKaminskyattacksharder,butnotimpossible.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstageRelevancetopassiveDNSWeimer's2005papernotesseveralproblemswithverifyingpassiveDNSdata.
KashpureandKaminskypoisoningof"activeDNS"haveanaloguesinpassiveDNS.
PassiveDNSsensorscan'tseetheDNScache's"bailiwick",leadingtorecordinjection.
Spoofedresponsesaretreatedjustlikenormalresponses.
AsinglespoofedresponsecanpoisonthepassiveDNSdatabase!
Goal:makepassiveDNSatleastasreliableasactiveDNS.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstageProtectingthecapturestageagainstresponsespoongCapturebothqueriesandresponses.
Correlateresponseswithpreviouslyseenqueries.
TheDNSmessage9-tuple:1.
InitiatorIPaddress2.
Initiatorport3.
TargetIPaddress4.
Targetport5.
Internetprotocol6.
DNSID7.
Queryname8.
Querytype9.
QueryclassRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagenmsg/dnsqrdnsqrisamessagemoduleforISC'slibnmsgspecicallydesignedforpassiveDNScapture.
UDPDNStransactionsareclassiedintothreecategories:1.
UDPQUERYRESPONSE2.
UDPUNANSWEREDQUERY3.
UDPUNSOLICITEDRESPONSEPerformsIPreassembly,too!
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstageProtectingtheanalysisstageagainstrecordinjectionCachesinternallyassociatea"bailiwick"witheachoutgoingquery.
Thecacheknowswhatbailiwicktouse,becauseitknowswhyit'ssendingaparticularquery.
Wehavetocalculatethebailiwickourselves.
Protectionagainstrecordinjectionrequiresprotectionagainstspoofedresponses.
(Otherwise,anattackercouldjustspooftherecordandthesourceIPaddressofanin-bailiwicknameserver.
)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmMustoperatecompletelypassively.
Mustprovideabooleantrueorfalseforeachrecord.
"Foreachrecordname,istheresponseIPaddressanameserverforthezonethatcontainsorcancontainthisname"Example:rootnameserverscanassertknowledgeaboutanyname!
Example:Verisign'sgtldserverscanassertknowledgeaboutanydomainnameendingin.
comor.
net.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmInitializebailiwickcachewithacopyoftherootzone.
CachestartsowithknowledgeofwhichserversservetherootandTLDs.
Findallpotentialzonesthatanamecouldbelocatedin.
Checkwhetheranyofthenameserversforthosezonesarethenameserverthatsenttheresponse.
EachtimeanNS,A,orAAAArecordisveriedbythealgorithm,itisinsertedintothebailiwickcache.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexampleName:example.
com.
Server:192.
5.
6.
30Potentialzones:example.
com.
com.
.
Zonesinbailiwickcache:com.
.
Check:example.
com.
/NSNotfound.
Check:com.
/NSFound13nameservers.
Check:areanyofthem192.
5.
6.
30Yes.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexamplecom.
INNSa.
gtldservers.
net.
a.
gtldservers.
net.
INA192.
5.
6.
30RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexample;;QUESTIONSECTION:;www.
example.
com.
INA;;AUTHORITYSECTION:example.
com.
172800INNSa.
ianaservers.
net.
example.
com.
172800INNSb.
ianaservers.
net.
;;ADDITIONALSECTION:a.
ianaservers.
net.
172800INA192.
0.
34.
43b.
ianaservers.
net.
172800INA193.
0.
0.
236;;SERVER:192.
5.
6.
30#53(192.
5.
6.
30)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexample;;QUESTIONSECTION:;www.
example.
com.
INA;;ANSWERSECTION:www.
example.
com.
172800INA192.
0.
32.
10;;AUTHORITYSECTION:example.
com.
172800INNSa.
ianaservers.
net.
example.
com.
172800INNSb.
ianaservers.
net.
;;SERVER:192.
0.
34.
43#53(192.
0.
34.
43)RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBRelevanceCapturestageAnalysisstagePassiveDNSbailiwickalgorithmexampleName:www.
example.
com.
Server:192.
0.
34.
43Potentialzones:www.
example.
com.
example.
com.
com.
.
Zonesinbailiwickcache:example.
com.
com.
.
Check:www.
example.
com.
/NSNotfound.
Check:example.
com.
/NSFound2nameservers.
Check:areanyofthem192.
0.
34.
43Yes.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesDNSDBDNSDBisadatabaseforstoringDNSrecords.
DataisloadedfrompassiveDNSandzoneles.
IndividualDNSrecordsarestoredinanApacheCassandradatabase.
Oerskey-valuestoredistributedacrossmultiplemachines.
GoodtforDNSdata.
Sustainsextremelyhighwritethroughputbecauseallwritesaresequential.
OersaRESTfulHTTPAPIandwebsearchinterface.
Databasecurrentlyconsumesabout500GBoutof27TB.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesArchitectureComponentsDatasourcesnmsg-dns-cacheDNSTLDzones(FTPviaZFAprograms):com,net,org,etc.
DNSzones(standardAXFR/IXFRprotocol)DataloadersDeduplicatedpassiveDNSZoneledataRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesDatasource:nmsg-dns-cacheReadsrawDNSresponsesfrompassiveDNS.
ParseseachDNSmessageintoindividualDNSRRsets.
Seriesofltersreducethetotalamountofdatabyabout50%.
RRsetsaretheninsertedintoanin-memorycache.
CacheisexpiredinFIFOorder.
WhenRRsetsexpirefromthecache,theyformthenalnmsg-dns-cacheoutput.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesDatasource:zonelesgTLDZoneFileAccessprograms:com,net,org,info,biz,nameAXFR'dzones:isc.
org,afewother"test"zones.
RobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesExample#1:*.
google.
comRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardeningIntroductionDNSSecurityIssuesPassiveDNShardeningDNSDBArchitectureExamplesRobertEdmondsPassiveDNSHardening
- features免费dns相关文档
- IP免费dns
- disrupt免费dns
- 支持免费dns
- Users免费dns
- 域名免费dns
- drop免费dns
妮妮云（119元/季）日本CN2 2核2G 30M 119元/季
妮妮云的知名度应该也不用多介绍了，妮妮云旗下的云产品提供商，相比起他家其他的产品，云产品还是非常良心的，经常出了一些优惠活动，前段时间的八折活动推出了很多优质产品，近期商家秒杀活动又上线了，秒杀产品比较全面，除了ECS和轻量云，还有一些免费空间、增值代购、云数据库等，如果你是刚入行安稳做站的朋友，可以先入手一个119/元季付的ECS来起步，非常稳定。官网地址：www.niniyun.com活动专区...
香港服务器租用多少钱一个月?影响香港服务器租用价格因素
香港服务器租用多少钱一个月?香港服务器受到很多朋友的青睐，其中免备案成为其特色之一。很多用户想了解香港云服务器价格多少钱，也有同行询问香港服务器的租赁价格，一些实际用户想要了解香港服务器的市场。虽然价格是关注的焦点，但价格并不是香港服务器的全部选择。今天小编介绍了一些影响香港服务器租赁价格的因素，以及在香港租一个月的服务器要花多少钱。影响香港服务器租赁价格的因素：1.香港机房选择香港机房相当于选择...
腾讯云爆款秒杀：1C2G5M服务器38元/年,CDN流量包6元起
农历春节将至，腾讯云开启了热门爆款云产品首单特惠秒杀活动，上海/北京/广州1核2G云服务器首年仅38元起，上架了新的首单优惠活动，每天三场秒杀，长期有效，其中轻量应用服务器2G内存5M带宽仅需年费38元起，其他产品比如CDN流量包、短信包、MySQL、直播流量包、标准存储等等产品也参与活动，腾讯云官网已注册且完成实名认证的国内站用户均可参与。活动页面：https://cloud.tencent.c...
免费dns为你推荐
-
phpcms模板phpcms v9 模板设置filezillaserver谁用过FileZilla_Server啊，请教www.topit.me提供好的图片网站ipad代理在哪买ipad更便宜加多宝和王老吉王老吉和加多宝的关系？银花珠树晓来看用黄皮比喻心酸的诗句刚刚网新员工入职自我介绍怎么写？爱买网超谁有http://www.25j58.com爱网购吧网站简介？申请400电话电话是什么电话啊？怎么申请400电话400呢？具体收费价格是什么？灌水机什么是论坛灌水机？在哪里可以下载到呢？