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NISTSpecialPublication800NISTSP800-233
ServiceMeshProxyModelsforCloud-NativeApplications
RamaswamyChandramouliZackButcher
JamesCallaghan
Thispublicationisavailablefreeofchargefrom:
/10.6028/NIST.SP.800-233
NISTSpecialPublication800NISTSP800-233
ServiceMeshProxyModelsforCloud-NativeApplications
RamaswamyChandramouli
ComputerSecurityDivisionInformationTechnologyLaboratory
ZackButcher
Tetrate,Inc.
JamesCallaghan
control-plane.io,
Inc.
Thispublicationisavailablefreeofchargefrom:
/10.6028/NIST.SP.800-233
October2024
U.S.DepartmentofCommerce
GinaM.Raimondo,Secretary
NationalInstituteofStandardsandTechnology
LaurieE.Locascio,NISTDirectorandUnderSecretaryofCommerceforStandardsandTechnology
NISTSP800-233ServiceMeshProxyModelsfor
October2024Cloud-NativeApplications
Certaincommercialequipment,instruments,software,ormaterials,commercialornon-commercial,areidentified
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TheremaybereferencesinthispublicationtootherpublicationscurrentlyunderdevelopmentbyNISTin
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/publications.
Authority
ThispublicationhasbeendevelopedbyNISTinaccordancewithitsstatutoryresponsibilitiesundertheFederal
InformationSecurityModernizationAct(FISMA)of2014,44U.S.C.§3551etseq.,PublicLaw(P.L.)113-283.NISTisresponsiblefordevelopinginformationsecuritystandardsandguidelines,includingminimumrequirementsfor
federalinformationsystems,butsuchstandardsandguidelinesshallnotapplytonationalsecuritysystems
withouttheexpressapprovalofappropriatefederalofficialsexercisingpolicyauthorityoversuchsystems.ThisguidelineisconsistentwiththerequirementsoftheOfficeofManagementandBudget(OMB)CircularA-130.
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bindingonfederalagenciesbytheSecretaryofCommerceunderstatutoryauthority.NorshouldtheseguidelinesbeinterpretedasalteringorsupersedingtheexistingauthoritiesoftheSecretaryofCommerce,Directorofthe
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Copyright,Use,andLicensingStatements
NISTTechnicalSeriesPublicationIdentifierSyntax
PublicationHistory
ApprovedbytheNISTEditorialReviewBoardon2024-10-11
HowtoCitethisNISTTechnicalSeriesPublication:
ChandramouliR,ButcherZ,CallaghanJ(2024)ServiceMeshProxyModelsforCloud-NativeApplications.(NationalInstituteofStandardsandTechnology,Gaithersburg,MD),NISTSpecialPublication(SP)NISTSP800-233.
/10.6028/NIST.SP.800-233
AuthorORCIDiDs
RamaswamyChandramouli:0000-0002-7387-5858
NISTSP800-233ServiceMeshProxyModelsfor
October2024Cloud-NativeApplications
ContactInformation
sp800-233-comments@
NationalInstituteofStandardsandTechnology
Attn:ComputerSecurityDivision,InformationTechnologyLaboratory
100BureauDrive(MailStop8930)Gaithersburg,MD20899-8930
AdditionalInformation
Additionalinformationaboutthispublicationisavailableat
/pubs/sp/800/233/final,
includingrelatedcontent,potentialupdates,anddocumenthistory.
AllcommentsaresubjecttoreleaseundertheFreedomofInformationAct(FOIA).
NISTSP800-233ServiceMeshProxyModelsfor
October2024Cloud-NativeApplications
i
Abstract
Theservicemeshhasbecomethedefactoapplicationservicesinfrastructureforcloud-nativeapplications.Itenablesthevariousruntimefunctionsofanapplicationthroughproxiesthat
formthedataplaneoftheservicemesh.Dependingonthedistributionofthenetworklayer
functionsandthegranularityofassociationoftheproxiestoindividualservicesandcomputingnodes,differentproxymodelsordataplanearchitectureshaveemerged.Thisdocument
describesathreatprofileforeachofthedataplanearchitectureswithadetailedthreatanalysistomakerecommendationsontheirapplicabilityforcloud-nativeapplicationswithdifferent
securityriskprofiles.
Keywords
cloud-nativeapplication;dataplanearchitecture;proxymodel;servicemesh;threatprofile.
ReportsonComputerSystemsTechnology
TheInformationTechnologyLaboratory(ITL)attheNationalInstituteofStandardsandTechnology(NIST)promotestheU.S.economyandpublicwelfarebyprovidingtechnical
leadershipfortheNation’smeasurementandstandardsinfrastructure.ITLdevelopstests,testmethods,referencedata,proofofconceptimplementations,andtechnicalanalysestoadvance
thedevelopmentandproductiveuseofinformationtechnology.ITL’sresponsibilitiesincludethedevelopmentofmanagement,administrative,technical,andphysicalstandardsand
guidelinesforthecost-effectivesecurityandprivacyofotherthannationalsecurity-related
informationinfederalinformationsystems.TheSpecialPublication800-seriesreportsonITL’sresearch,guidelines,andoutreacheffortsininformationsystemsecurity,anditscollaborativeactivitieswithindustry,government,andacademicorganizations.
NISTSP800-233ServiceMeshProxyModelsfor
October2024Cloud-NativeApplications
ii
PatentDisclosureNotice
NOTICE:ITLhasrequestedthatholdersofpatentclaimswhoseusemayberequiredfor
compliancewiththeguidanceorrequirementsofthispublicationdisclosesuchpatentclaimstoITL.However,holdersofpatentsarenotobligatedtorespondtoITLcallsforpatentsandITLhasnotundertakenapatentsearchinordertoidentifywhich,ifany,patentsmayapplytothis
publication.
Asofthedateofpublicationandfollowingcall(s)fortheidentificationofpatentclaimswhoseusemayberequiredforcompliancewiththeguidanceorrequirementsofthispublication,nosuchpatentclaimshavebeenidentifiedtoITL.
NorepresentationismadeorimpliedbyITLthatlicensesarenotrequiredtoavoidpatentinfringementintheuseofthispublication.
NISTSP800-233ServiceMeshProxyModelsfor
October2024Cloud-NativeApplications
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TableofContents
ExecutiveSummary 1
1.Introduction 2
1.1.L4andI7Functionsofproies…3
12.0bectieandTargetAudience.…………3
13.elationshiptootherNISTDocuments………………4
1.4.Documentstucture…4
2.TypicalServiceMeshDataPlaneCapabilitiesandAssociatedProxyFunctions 5
3.ProxyModels(DataPlaneArchitectures)inServiceMeshImplementations 7
31.L4and17proxypersericelnstance(OPA-)-sidecarModel…7
32.sharedL4-L7perseniceModel(OPA.2h……….8
3.3.sharedL4andL7Model(DPA-3).........9
3.A,L4andL7aspartoftheApplicationModel(OPA-4)l………10
4.DataPlaneArchitectureThreatScenariosandAnalysisMethodology 12
4.1.ThreatAnalsiMethodology….13
5.DetailedThreatAnalysisforDataPlaneArchitectures 14
5.1.ThreatAnalysisforL4andL7proxyperserviceInstance(DPA-1)—sidecarModel...........14
5.1.1.CompromisedL4Proxy(TR-1) 14
5.1.2.CompromisedApplicationContainer(TR-2) 14
5.1.3.CompromiseofBusinessData(TR-3) 15
5.1.4.CompromisedL7Proxy(TR-4) 15
5.1.5.CompromiseofSharedL7Proxy(TR-5) 15
5.1.6.OutdatedClientLibrariesinApplications(TR-6) 16
5.1.7.DenialofService(TR-7) 16
5.1.8.ResourceConsumption(TR-8) 17
5.1.9.PrivilegedL4Proxy(TR-9) 17
5.1.10.DataPlane(ServiceMesh)Bypassed(TR-10) 17
5.1.11OverallThreatScore 18
52.ThreatAnalysisforsharedL4-L7perseniceModel(OPA-2)……18
5.2.1.CompromisedL4Proxy(TR-1) 18
5.2.2.CompromisedApplicationContainer(TR-2) 18
5.2.3.CompromiseofBusinessData(TR-3) 18
5.2.4.CompromisedL7Proxy(TR-4) 19
5.2.5.CompromiseofSharedL7Proxy(TR-5) 19
5.2.6.OutdatedClientLibrariesinApplications(TR-6) 19
NISTSP800-233ServiceMeshProxyModelsfor
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iv
5.2.7.DenialofService(TR-7) 19
5.2.8.ResourceConsumption(TR-8) 20
5.2.9PrivilegedL4Proxy(TR-9) 20
5.2.10DataPlane(ServiceMesh)Bypassed(TR-10) 21
5.2.11OverallThreatScore 21
5.3.1.CompromisedL4Proxy(TR-1) 21
5.3.2.CompromisedApplicationContainer(TR-2) 22
5.3.3.CompromiseofBusinessData(TR-3) 22
5.3.4.CompromisedL7Proxy(TR-4) 22
5.3.5.CompromiseofSharedL7Proxy(TR-5) 23
5.3.6.OutdatedClientLibrariesinApplications(TR-6) 23
5.3.7.DenialofService(TR-7) 23
5.3.8.ResourceConsumption(TR-8) 23
5.3.9.PrivilegedL4Proxy(TR-9) 24
5.3.10.DataPlane(ServiceMesh)Bypassed(TR-10) 24
5.3.11OverallThreatScore 24
5.4.ThreatAnalysisforL4andL7aspartoftheApplicationModel(gRpcproxylessModel(DPA-4))
25
5.4.1.CompromisedL4Proxy(TR-1) 25
5.4.2.CompromisedApplicationContainer(TR-2) 25
5.4.3.CompromiseofBusinessData(TR-3) 25
5.4.4.CompromisedL7Proxy(TR-4) 25
5.4.5.CompromiseofSharedL7Proxy(TR-5) 26
5.4.6.OutdatedClientLibrariesinApplications(TR-6) 26
5.4.7.DenialofService(TR-7) 26
5.4.8.ResourceConsumption(TR-8) 27
5.4.9PrivilegedL4Proxy(TR-9) 27
5.4.10DataPlane(ServiceMesh)Bypassed(TR-10) 27
5.4.11OverallThreatScore 28
6.RecommendationsBasedontheApplicationSecurityRiskProfile 29
7.SummaryandConclusions............................................................................................................32
NISTSP800-233ServiceMeshProxyModelsfor
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References.......................................................................................................................................33
NISTSP800-233ServiceMeshProxyModelsfor
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Acknowledgments
TheauthorswouldliketoexpresstheirthankstoFrancescoBeltraminiofcontrol-plane.ioforparticipatingindiscussionsandprovidinghisvaluableperspective.TheauthorswouldalsoliketoexpresstheirthankstoIsabelVanWykofNISTforherdetailededitorialreview,bothforthepubliccommentversionaswellasforthefinalpublication
1
ExecutiveSummary
Acentralizedinfrastructurecalledaservicemeshcanproviderun-timeservicesforcloud-nativeapplicationsthatconsistofmultiplelooselycoupledcomponentscalledmicroservices.These
servicesincludesecurecommunication,servicediscovery,resiliency,andauthorizationof
applicationcommunication.Theseservicesaremainlyprovidedthroughproxiesthatformthedataplaneoftheservicemesh,whichisthelayerthathandlesapplicationtrafficatruntime
andenforcespolicy.
ThefunctionsthattheproxiesprovidecanbebroadlycategorizedintotwogroupsbasedontheOpenSystemsInterconnection(OSI)model’snetworklayertowhichthosefunctionspertain:
Layer4(“L4”)andLayer7(“L7”).Inmostservicemeshdeploymentsinproduction
environmentstoday,allproxyfunctionsthatprovideservicesinbothL4andL7layersare
packedintoasingleproxythatisassignedtoasinglemicroservice.Thisservicemeshproxy
modeliscalledasidecarproxymodelsincetheproxyisnotonlyassociatedwithasingleservicebutisimplementedtoexecuteinthesamenetworkspaceastheservice.
However,performanceandresourceconsiderationshaveledtotheexplorationofalternate
proxymodelsthatinvolvesplittingL4andL7functionsintodifferentproxiesandthe
associationorassignmentsoftheseproxiestoeitherasingleserviceoragroupofservices.Thisenablestheproxiestobeimplementedatdifferentlocationsatthegranularityofanoderatherthanatthelevelofservices.Thoughdifferentmodelsaretheoreticallypossible,thisdocumentonlyconsidersservicemeshproxymodelsinthedataplaneimplementationofcommonlyusedservicemeshofferingsatdifferentstages.
Variouspotentialorlikelythreatstoproxyfunctionsmayresultindifferenttypesofexploitsindifferentproxymodels.Thisvariationisduetoseveralfactors,suchastheattacksurface(i.e.,
communicationpatternstowhichaparticularproxyisexposed),thenumberofclients
(services)served,andtheOSIlayerfunctionsthattheyprovide(e.g.,L7functionsaremorecomplicatedandlikelytohavemorevulnerabilitiesthanL4functions).Thetwomain
contributionsofthisdocumentarethefollowing:
1.Thenatureoftheexploitsthatarepossibleforeachthreatineachoftheproxymodelsischaracterizedbyassigningscorestotheimpactandlikelihoodofeachofthethreatsineachoftheproxymodelsorarchitecturalpatterns,resultinginathreatprofilethatis
associatedwitheacharchitecturalpatternorproxymodelofservicemesh.
2.Eachthreatprofilehasaninherentsetofsecuritytrade-offsatanarchitecturallevel.
Theimplicationsofthesetrade-offsinmeetingtherequirementsassociatedwiththe
securityriskprofilesofdifferentcloud-nativeapplicationsareanalyzedtomakeabroadsetofrecommendationstowardspecificarchitecturalpatternsthatareappropriateforapplicationswithdifferentsecurityriskprofiles.
NISTSP800-233ServiceMeshProxyModelsfor
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1.Introduction
“Cloud-native”referstoanarchitecturalphilosophyforbuildingscalable,resilientsystemsthat
aredesignedtoleveragetheadvantagesofcloudcomputingenvironments.Cloud-native
applicationscanrunbothon-premisesandinpubliccloudplatformsandarenormallybuilt
usingagiledevelopmentmethodologies,suchascontinuousintegration/continuousdelivery(CI/CD).Typically,technologiessuchascontainerizationandvirtualmachines(VMs)areused,andresilienceandfail-safefeatureswillbebuiltin.
Microservices-basedapplicationsuseanarchitecturalapproachinwhichtheentireapplicationisbrokenintolooselycoupledcomponentsthatcanbeindependentlyupdatedandscaled.Theimplementationofmicroservicesisenabledusingcontainersthatinturnrequireorchestrationtoolsandoftenemployacentralizedservicesinfrastructure(e.g.,servicemesh)toprovideallruntimeapplicationservices,includingnetworkconnectivity,security,resiliency,and
monitoringcapabilities.Microservices-basedapplicationscanbeimplementedanddeployedascloud-native,thoughtheyrepresentanindependentarchitecturalapproach.
Theinfrastructureservicesorfunctionsprovidedbyaservicemeshduringapplicationruntimeareprovidedbyentitiescalledproxies,whichconstitutethedataplaneoftheservicemesh.Inaddition,theservicemeshconsistsofanotherarchitecturalcomponentcalledthecontrol
plane,whichsupportsthefunctionsofthedataplanethroughinterfacestodefine
configurations,injectsoftwareprograms,andprovidesecurityartifacts(e.g.,certificates).
Variousconfigurationsforproxiesarebeingdevelopedandtestedbasedontheperformanceandsecurityassurancedataobtainedduringthedeploymentofservicemeshoverthelast
severalyears.Theseconfigurationsareproxy(implementation)modelsthatarebasedontheOSIlayerfunctionsthattheyprovide(describedinthefollowingparagraphs)andthe
granularityofassociationbetweenaproxyandservices.Sinceproxiesarethepredominantentitiesofthedataplaneofaservicemesh,thesevariousproxymodelsarealsocalleddataplanearchitectures.
TheOSImodel
[1]
isausefulabstractionforthinkingaboutthefunctionsrequiredtoserveanapplicationoverthenetwork.Itdescribesseven“layers,”fromthephysicalwiresthatconnecttwomachines(i.e.,Layer1–L1,thephysicallayer)totheapplicationitself(i.e.,Layer7–L7,theapplicationlayer).
Layers3,4,and7arekeytofacilitatingcommunicationbetweencloud-nativeapplications(e.g.,twomicroservicesmakingHypertextTransferProtocol(HTTP)/RESTcallstoeachother):
•Layer3(“L3”),thenetworklayer,facilitatesbaselineconnectivitybetweentwo
workloadsorserviceinstances.Innearlyallcases,theInternetProtocol(IP)isusedastheL3implementation.
•Layer4(“L4”),thetransportlayer,facilitatesthereliabletransmissionofdatabetweenworkloadsonthenetwork.Italsoincludescapabilitieslikeencryption.TransportControlProtocol(TCP)andUserDatagramProtocol(UDP)arecommonlyusedL4
implementations,wheretransportlayersecurity(TLS)providesencryption.
NISTSP800-233ServiceMeshProxyModelsfor
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3
•Layer7(“L7”),theapplicationlayer,iswhereprotocolslikeHTTPoperate—inuserapplicationsthemselves(e.g.,HTTPwebservers,SecureShell(SSH)servers).
Withrespecttothelayersabove,aservicemesh’sproxiesincloud-nativeenvironmentsare:
•AgnostictoL3ifthemicroserviceinstancescancommunicateatL3andtheproxycancommunicatewiththemesh’scontrolplane.
•AtLayer4(L4):Connectionestablishment,management,andresiliency(e.g.,
connection-levelretries);TLS(encryptionintransit);applicationidentity,authentication,andauthorization;accesspolicybasedonnetwork5-tuple(e.g.,sourceIPaddressand
port,destinationIPaddressandport,andtransportprotocol).
•AtLayer7(L7):Servicediscovery,request-levelresiliency(e.g.,retries,circuitbreakers,
outlierdetection);andapplicationobservability.
1.1.L4andL7FunctionsofProxies
Therearetwokeyaspectsofproxymodels:
1.Proxyfunctions:Thefunctionsthataservicemesh’sproxiesprovidecanbebroadly
categorizedintotwogroupsbasedontheOSImodel’slayer
[1]
towhichthosefunctionspertain:Layer4(“L4”)andLayer7(“L7”).TheassociatedproxiesarecalledL4proxies
andL7proxies,respectively.ThestudyofproxyfunctionsrequiresanunderstandingoftheOSI’sL4andL7layersfromthenetworkstackpointofviewandthespecificnetworkservicesprovidedbythoselayers.
2.Granularityofassociation:Aproxycanbeassociatedwithasinglemicroserviceinstance,anentireservice,ordeployedtoprovidefunctionsforagroupofservices.Dependingonthenatureofthisassociation,aproxymayexecutewithinthesamenetworkspaceas
theservice,atthesamenodewherethegroupofservicestowhichitcatersrun,orinanindependentnodededicatedtoproxieswherenoapplicationservicesrun.
1.2.ObjectiveandTargetAudience
Thisdocumentwillgiveabriefoverviewofthefourdataplanearchitectures(proxymodels)beingpursuedbyarangeofservicemeshimplementationstoday.Itwillalsoprovidethreatprofilesfordifferentproxymodelswithadetailedthreatanalysisthatinvolves10typesofcommonthreats.Thesethreatprofileswillinformrecommendationsregardingtheir
applicability(usage)forcloud-nativeapplicationswithdifferentsecurityriskprofiles.Thetargetaudiencefortheserecommendationsincludes:
•Infrastructureowners,platform/infrastructureengineers,andtheirteamleaderswhobuildanddeploysecureruntimeenvironmentsforapplicationsbychoosingtherightarchitecturefortheirenvironmentgiventheriskfactorsoftheapplicationsthattheywillberunningandtheresultingsecurityriskprofile.
NISTSP800-233ServiceMeshProxyModelsfor
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4
•Personnelinchargeofinfrastructureoperationswhoneedtobefamiliarwiththe
variousbuildingblocksoftheproxymodelsordataplanearchitectures(andtheir
associatedfunctionsandinteractions)totroubleshootintheeventofperformance(i.e.,availability)andsecurityissues
1.3.RelationshiptoOtherNISTDocuments
ThisdocumentcanbeusedasanadjuncttotheNISTSpecialPublication(SP)800-204seriesofpublications
[2][3][4][5],
whichofferguidanceonprovidingsecurityassuranceforcloud-native
applicationsintegratedwithaservicemeshfromthefollowingperspectives:strategy,
configuration,anddevelopment/deploymentparadigm.However,thisdocumentfocuseson
thevariousconfigurationsoftheapplicationserviceinfrastructureelements(i.e.,proxies)andtheresultingarchitectures(i.e.,dataplanearchitectureoftheservicemesh)thathavedifferent
securityimplicationsfortheapplicationthatishostedundereachoftheseconfigurations.
1.4.DocumentStructure
Thisdocumentisorganizedasfollows:
•
•
•
•
•
•
Section
2
liststhetypicalcapabilitiesofthedataplaneoftheservicemeshunderthreeheadings(i.e.,security,observability,andtrafficmanagement)andthecorrespondingL4andL7proxyfunctionsimplementedunderthosecapabilities.
Section
3
providesabriefoverviewofthefourproxymodelsordataplanearchitectures.Section
4
discussesproxymodelthreatscenariosandthethreatanalysismethodologyadoptedinthisdocumentforevaluatingthethreatprofilescoreforthefourdataplanearchitectures.
Section
5
providesadetailedthreatanalysisforthefourdataplanearchitecturesbyassigningscorestotheimpactandlikelihoodfactorsassociatedwitheachthreatandusingthemtoarriveatanoverallthreatscore.
Section
0
providesrecommendationsontheapplicability(usage)ofeachofthefourdataplanearchitecturesforcloud-nativeapplicationsofdifferentsecurityriskprofilesbasedontheirsecurityrequirements.
Section
0
providesthesummaryandconclusions.
NISTSP800-233ServiceMeshProxyModelsfor
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5
2.TypicalServiceMeshDataPlaneCapabilitiesandAssociatedProxyFunctions
Thisdocument’smethodologyexaminesthesecuritytrade-offsoftheproxymodels(i.e.,data
planearchitectures)andtheimplementationsofthevariouscapabilitiesthatresultasL4andL7functionsinproxies.Determiningthetotalityofproxyfunctionsrequiresananalysisofeach
capability,thecategoryitfallsunder,andthegranularityofthefunctionthatitprovidesatL4andL7levels.
Table1-SecurityCapabilities[15]
Capability
L4Function(s)
L7Function(s)
Service-to-serviceauthentication
SPIFFE,
viamTLScerts.Control
planeissuesashort-livedX.509
encodingt
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