rfc2574.User-based Security Model (USM) for versio

NetworkWorkingGroupU.BlumenthalRequestforComments:2574IBMT.J.WatsonResearchObsoletes:2274B.WijnenCategory:StandardsTrackIBMT.J.WatsonResearchApril1999User-basedSecurityModel(USM)forversion3oftheSimpleNetworkManagementProtocol(SNMPv3)StatusofthisMemoThisdocumentspecifiesanInternetstandardstrackprotocolfortheInternetcommunity,andrequestsdiscussionandsuggestionsforimprovements.PleaserefertothecurrenteditionoftheInternetOfficialProtocolStandards(STD1)forthestandardizationstateandstatusofthisprotocol.Distributionofthismemoisunlimited.CopyrightNoticeCopyright(C)TheInternetSociety(1999).AllRightsReserved.AbstractThisdocumentdescribestheUser-basedSecurityModel(USM)forSNMPversion3foruseintheSNMParchitecture[RFC2571].ItdefinestheElementsofProcedureforprovidingSNMPmessagelevelsecurity.ThisdocumentalsoincludesaMIBforremotelymonitoring/managingtheconfigurationparametersforthisSecurityModel.TableofContents1.Introduction31.1.Threats41.2.GoalsandConstraints51.3.SecurityServices61.4.ModuleOrganization71.4.1.TimelinessModule71.4.2.AuthenticationProtocol81.4.3.PrivacyProtocol81.5.ProtectionagainstMessageReplay,DelayandRedirection81.5.1.AuthoritativeSNMPengine81.5.2.Mechanisms91.6.AbstractServiceInterfaces101.6.1.User-basedSecurityModelPrimitivesforAuthentication111.6.2.User-basedSecurityModelPrimitivesforPrivacy112.ElementsoftheModel122.1.User-basedSecurityModelUsers12Blumenthal&WijnenStandardsTrack[Page1]RFC2574USMforSNMPv3April19992.2.ReplayProtection132.2.1.msgAuthoritativeEngineID132.2.2.msgAuthoritativeEngineBootsandmsgAuthoritativeEngineTime142.2.3.TimeWindow152.3.TimeSynchronization152.4.SNMPMessagesUsingthisSecurityModel162.5.ServicesprovidedbytheUser-basedSecurityModel172.5.1.ServicesforGeneratinganOutgoingSNMPMessage172.5.2.ServicesforProcessinganIncomingSNMPMessage192.6.KeyLocalizationAlgorithm.213.ElementsofProcedure213.1.GeneratinganOutgoingSNMPMessage223.2.ProcessinganIncomingSNMPMessage254.Discovery305.Definitions316.HMAC-MD5-96AuthenticationProtocol506.1.Mechanisms506.1.1.DigestAuthenticationMechanism506.2.ElementsoftheDigestAuthenticationProtocol516.2.1.Users516.2.2.msgAuthoritativeEngineID516.2.3.SNMPMessagesUsingthisAuthenticationProtocol516.2.4.ServicesprovidedbytheHMAC-MD5-96AuthenticationModule526.2.4.1.ServicesforGeneratinganOutgoingSNMPMessage526.2.4.2.ServicesforProcessinganIncomingSNMPMessage536.3.ElementsofProcedure536.3.1.ProcessinganOutgoingMessage546.3.2.ProcessinganIncomingMessage547.HMAC-SHA-96AuthenticationProtocol557.1.Mechanisms557.1.1.DigestAuthenticationMechanism567.2.ElementsoftheHMAC-SHA-96AuthenticationProtocol567.2.1.Users567.2.2.msgAuthoritativeEngineID577.2.3.SNMPMessagesUsingthisAuthenticationProtocol577.2.4.ServicesprovidedbytheHMAC-SHA-96AuthenticationModule577.2.4.1.ServicesforGeneratinganOutgoingSNMPMessage577.2.4.2.ServicesforProcessinganIncomingSNMPMessage587.3.ElementsofProcedure597.3.1.ProcessinganOutgoingMessage597.3.2.ProcessinganIncomingMessage608.CBC-DESSymmetricEncryptionProtocol618.1.Mechanisms618.1.1.SymmetricEncryptionProtocol618.1.1.1.DESkeyandInitializationVector.628.1.1.2.DataEncryption.638.1.1.3.DataDecryption638.2.ElementsoftheDESPrivacyProtocol63Blumenthal&WijnenStandardsTrack[Page2]RFC2574USMforSNMPv3April19998.2.1.Users638.2.2.msgAuthoritativeEngineID648.2.3.SNMPMessagesUsingthisPrivacyProtocol648.2.4.ServicesprovidedbytheDESPrivacyModule648.2.4.1.ServicesforEncryptingOutgoingData648.2.4.2.ServicesforDecryptingIncomingData658.3.ElementsofProcedure.668.3.1.ProcessinganOutgoingMessage668.3.2.ProcessinganIncomingMessage669.IntellectualProperty6710.Acknowledgements6711.SecurityConsiderations6911.1.RecommendedPractices6911.2.DefiningUsers7111.3.Conformance7211.4.UseofReports7211.5.AccesstotheSNMP-USER-BASED-SM-MIB7212.References7313.Editors’Addresses75A.1.SNMPengineInstallationParameters76A.2.PasswordtoKeyAlgorithm78A.2.1.PasswordtoKeySampleCodeforMD579A.2.2.PasswordtoKeySampleCodeforSHA80A.3.PasswordtoKeySampleResults81A.3.1.PasswordtoKeySampleResultsusingMD581A.3.2.PasswordtoKeySampleResultsusingSHA81A.4.SampleencodingofmsgSecurityParameters82A.5.SamplekeyChangeResults83A.5.1.SamplekeyChangeResultsusingMD583A.5.2.SamplekeyChangeResultsusingSHA84B.ChangeLog85C.FullCopyrightStatement861.IntroductionTheArchitecturefordescribingInternetManagementFrameworks[RFC2571]describesthatanSNMPengineiscomposedof:1)aDispatcher2)aMessageProcessingSubsystem,3)aSecuritySubsystem,and4)anAccessControlSubsystem.Applicationsmakeuseoftheservicesofthesesubsystems.ItisimportanttounderstandtheSNMParchitectureandtheterminologyofthearchitecturetounderstandwheretheSecurityModeldescribedinthisdocumentfitsintothearchitectureandBlumenthal&WijnenStandardsTrack[Page3]RFC2574USMforSNMPv3April1999interactswithothersubsystemswithinthearchitecture.ThereaderisexpectedtohavereadandunderstoodthedescriptionoftheSNMParchitecture,asdefinedin[RFC2571].Thismemo[RFC2274]describestheUser-basedSecurityModelasitisusedwithintheSNMPArchitecture.Themainideaisthatweusethetraditionalconceptofauser(identifiedbyauserNa