# Initial SNMP engine configuration functions. During further operation,
# SNMP engine might be configured remotely (through SNMP).
from pyasn1.compat.octets import null
from pysnmp.carrier.asyncore.dgram import udp, udp6, unix
from pysnmp.proto.secmod.rfc3414.auth import hmacmd5, hmacsha, noauth
from pysnmp.proto.secmod.rfc3414.priv import des, nopriv
from pysnmp.proto.secmod.rfc3826.priv import aes
from pysnmp.proto.secmod.eso.priv import des3, aes192, aes256
from pysnmp import error

# A shortcut to popular constants

# Transports
snmpUDPDomain = udp.snmpUDPDomain
snmpUDP6Domain = udp6.snmpUDP6Domain
snmpLocalDomain = unix.snmpLocalDomain

# Auth protocol
usmHMACMD5AuthProtocol = hmacmd5.HmacMd5.serviceID
usmHMACSHAAuthProtocol = hmacsha.HmacSha.serviceID
usmNoAuthProtocol = noauth.NoAuth.serviceID

# Privacy protocol
usmDESPrivProtocol = des.Des.serviceID
usm3DESEDEPrivProtocol = des3.Des3.serviceID
usmAesCfb128Protocol = aes.Aes.serviceID
usmAesCfb192Protocol = aes192.Aes192.serviceID
usmAesCfb256Protocol = aes256.Aes256.serviceID
usmNoPrivProtocol = nopriv.NoPriv.serviceID

# Auth services
authServices = {
    hmacmd5.HmacMd5.serviceID: hmacmd5.HmacMd5(),
    hmacsha.HmacSha.serviceID: hmacsha.HmacSha(),
    noauth.NoAuth.serviceID: noauth.NoAuth()
    }

# Privacy services
privServices = {
    des.Des.serviceID: des.Des(),
    des3.Des3.serviceID: des3.Des3(),        
    aes.Aes.serviceID: aes.Aes(),
    aes192.Aes192.serviceID: aes192.Aes192(),
    aes256.Aes256.serviceID: aes256.Aes256(),
    nopriv.NoPriv.serviceID: nopriv.NoPriv()
    }
    
def __cookV1SystemInfo(snmpEngine, communityIndex):
    snmpEngineID, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')

    snmpCommunityEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-COMMUNITY-MIB', 'snmpCommunityEntry')
    tblIdx = snmpCommunityEntry.getInstIdFromIndices(communityIndex)
    return snmpCommunityEntry, tblIdx, snmpEngineID
    
def addV1System(snmpEngine, communityIndex, communityName,
                contextEngineId=None, contextName=None,
                transportTag=None, securityName=None):
    snmpCommunityEntry, tblIdx, snmpEngineID = __cookV1SystemInfo(
        snmpEngine, communityIndex
    )

    if contextEngineId is None:
        contextEngineId = snmpEngineID.syntax
    else:
        contextEngineId = snmpEngineID.syntax.clone(contextEngineId)

    if contextName is None:
        contextName = null

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpCommunityEntry.name + (8,) + tblIdx, 'destroy'),)
    )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpCommunityEntry.name + (8,) + tblIdx, 'createAndGo'),
         (snmpCommunityEntry.name + (1,) + tblIdx, communityIndex),
         (snmpCommunityEntry.name + (2,) + tblIdx, communityName),
         (snmpCommunityEntry.name + (3,) + tblIdx, securityName is not None and securityName or communityIndex),
         (snmpCommunityEntry.name + (4,) + tblIdx, contextEngineId),
         (snmpCommunityEntry.name + (5,) + tblIdx, contextName),
         (snmpCommunityEntry.name + (6,) + tblIdx, transportTag),
         (snmpCommunityEntry.name + (7,) + tblIdx, 'nonVolatile'))
    )

def delV1System(snmpEngine, communityIndex):
    snmpCommunityEntry, tblIdx, snmpEngineID = __cookV1SystemInfo(
        snmpEngine, communityIndex
    )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpCommunityEntry.name + (8,) + tblIdx, 'destroy'),)
    )

def __cookV3UserInfo(snmpEngine, securityName, securityEngineId):
    snmpEngineID, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('__SNMP-FRAMEWORK-MIB', 'snmpEngineID')
    if securityEngineId is None:
        snmpEngineID = snmpEngineID.syntax
    else:
        snmpEngineID = snmpEngineID.syntax.clone(securityEngineId)

    usmUserEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-USER-BASED-SM-MIB', 'usmUserEntry')
    tblIdx1 = usmUserEntry.getInstIdFromIndices(
        snmpEngineID, securityName
    )

    pysnmpUsmSecretEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('PYSNMP-USM-MIB', 'pysnmpUsmSecretEntry')
    tblIdx2 = pysnmpUsmSecretEntry.getInstIdFromIndices(securityName)

    return snmpEngineID, usmUserEntry, tblIdx1, pysnmpUsmSecretEntry, tblIdx2

def addV3User(snmpEngine, userName,
              authProtocol=usmNoAuthProtocol, authKey=None,
              privProtocol=usmNoPrivProtocol, privKey=None,
              securityEngineId=None,
              securityName=None,
              # deprecated parameters follow
              contextEngineId=None):
    if securityName is None:
        securityName = userName
    if securityEngineId is None:  # backward compatibility
        securityEngineId = contextEngineId
    ( snmpEngineID, usmUserEntry, tblIdx1,
      pysnmpUsmSecretEntry, tblIdx2 ) = __cookV3UserInfo(
        snmpEngine, userName, securityEngineId
    )

    # Load augmenting table before creating new row in base one
    pysnmpUsmKeyEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('PYSNMP-USM-MIB', 'pysnmpUsmKeyEntry')

    # Load clone-from (may not be needed)
    zeroDotZero, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMPv2-SMI', 'zeroDotZero')

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((usmUserEntry.name + (13,) + tblIdx1, 'destroy'),)
    )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((usmUserEntry.name + (13,) + tblIdx1, 'createAndGo'),
         (usmUserEntry.name + (2,) + tblIdx1, userName),
         (usmUserEntry.name + (3,) + tblIdx1, securityName),
         (usmUserEntry.name + (4,) + tblIdx1, zeroDotZero.name),
         (usmUserEntry.name + (5,) + tblIdx1, authProtocol),
         (usmUserEntry.name + (8,) + tblIdx1, privProtocol))
    )

    # Localize keys
    if authProtocol in authServices:
        hashedAuthPassphrase = authServices[authProtocol].hashPassphrase(
            authKey and authKey or null
        )
        localAuthKey = authServices[authProtocol].localizeKey(
            hashedAuthPassphrase, snmpEngineID
        )
    else:
        raise error.PySnmpError('Unknown auth protocol %s' % (authProtocol,))

    if privProtocol in privServices:
        hashedPrivPassphrase = privServices[privProtocol].hashPassphrase(
            authProtocol, privKey and privKey or null
        )
        localPrivKey = privServices[privProtocol].localizeKey(
            authProtocol, hashedPrivPassphrase, snmpEngineID
        )
    else:
        raise error.PySnmpError(
            'Unknown priv protocol %s' % (privProtocol,)
        )

    # Commit localized keys
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((pysnmpUsmKeyEntry.name + (1,) + tblIdx1, localAuthKey),
         (pysnmpUsmKeyEntry.name + (2,) + tblIdx1, localPrivKey),
         (pysnmpUsmKeyEntry.name + (3,) + tblIdx1, hashedAuthPassphrase),
         (pysnmpUsmKeyEntry.name + (4,) + tblIdx1, hashedPrivPassphrase))
        )

    # Commit passphrases

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((pysnmpUsmSecretEntry.name + (4,) + tblIdx2, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((pysnmpUsmSecretEntry.name + (4,) + tblIdx2, 'createAndGo'),
         (pysnmpUsmSecretEntry.name + (2,) + tblIdx2, authKey),
         (pysnmpUsmSecretEntry.name + (3,) + tblIdx2, privKey),)
        )

def delV3User(snmpEngine,
              userName,
              securityEngineId=None,
              # deprecated parameters follow
              contextEngineId=None):
    if securityEngineId is None:  # backward compatibility
        securityEngineId = contextEngineId
    ( snmpEngineID, usmUserEntry, tblIdx1,
      pysnmpUsmSecretEntry, tblIdx2 ) = __cookV3UserInfo(
        snmpEngine, userName, securityEngineId
    )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((usmUserEntry.name + (13,) + tblIdx1, 'destroy'),)
    )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((pysnmpUsmSecretEntry.name + (4,) + tblIdx2, 'destroy'),)
    )

    # Drop all derived rows
    varBinds = initialVarBinds = (
        (usmUserEntry.name + (1,), None),  # usmUserEngineID
        (usmUserEntry.name + (2,), None),  # usmUserName
        (usmUserEntry.name + (4,), None)   # usmUserCloneFrom
    )
    while varBinds:
        varBinds = snmpEngine.msgAndPduDsp.mibInstrumController.readNextVars(
            varBinds
        )
        if varBinds[0][0][:len(initialVarBinds[0][0])]!=initialVarBinds[0][0]:
            break
        elif varBinds[2][1] == tblIdx1:  # cloned from this entry
            delV3User(snmpEngine, varBinds[1][1], varBinds[0][1])
            varBinds = initialVarBinds

def __cookTargetParamsInfo(snmpEngine, name):
    snmpTargetParamsEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetParamsEntry')
    tblIdx = snmpTargetParamsEntry.getInstIdFromIndices(name)
    return snmpTargetParamsEntry, tblIdx
    
def addTargetParams(
    snmpEngine,
    name,
    securityName,
    securityLevel,
    mpModel=3  # 0 == SNMPv1, 1 == SNMPv2c, 3 == SNMPv3
    ):
    if mpModel == 0:
        securityModel = 1
    elif mpModel == 1 or mpModel == 2:
        securityModel = 2
    elif mpModel == 3:
        securityModel = 3
    else:
        raise error.PySnmpError('Unknown MP model %s' % mpModel)

    snmpTargetParamsEntry, tblIdx = __cookTargetParamsInfo(snmpEngine, name)
    
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpTargetParamsEntry.name + (7,) + tblIdx, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpTargetParamsEntry.name + (7,) + tblIdx, 'createAndGo'),
         (snmpTargetParamsEntry.name + (1,) + tblIdx, name),
         (snmpTargetParamsEntry.name + (2,) + tblIdx, mpModel),
         (snmpTargetParamsEntry.name + (3,) + tblIdx, securityModel),
         (snmpTargetParamsEntry.name + (4,) + tblIdx, securityName),
         (snmpTargetParamsEntry.name + (5,) + tblIdx, securityLevel))
        )

def delTargetParams(snmpEngine, name):
    snmpTargetParamsEntry, tblIdx = __cookTargetParamsInfo(
        snmpEngine, name
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpTargetParamsEntry.name + (7,) + tblIdx, 'destroy'),)
        )

def __cookTargetAddrInfo(snmpEngine, addrName):
    snmpTargetAddrEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-TARGET-MIB', 'snmpTargetAddrEntry')
    snmpSourceAddrEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('PYSNMP-SOURCE-MIB', 'snmpSourceAddrEntry')
    tblIdx = snmpTargetAddrEntry.getInstIdFromIndices(addrName)
    return snmpTargetAddrEntry, snmpSourceAddrEntry, tblIdx

def addTargetAddr(
    snmpEngine,
    addrName,
    transportDomain,    
    transportAddress,
    params,
    timeout=None,
    retryCount=None,
    tagList=null,
    sourceAddress=None
    ):
    snmpTargetAddrEntry, snmpSourceAddrEntry, tblIdx = __cookTargetAddrInfo(
        snmpEngine, addrName
        )
    
    if transportDomain[:len(snmpUDPDomain)] == snmpUDPDomain:
        SnmpUDPAddress, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMPv2-TM', 'SnmpUDPAddress')
        transportAddress = SnmpUDPAddress(transportAddress)
        if sourceAddress is None:
            sourceAddress = ('0.0.0.0', 0)
        sourceAddress = SnmpUDPAddress(sourceAddress)
    elif transportDomain[:len(snmpUDP6Domain)] == snmpUDP6Domain:
        TransportAddressIPv6, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('TRANSPORT-ADDRESS-MIB', 'TransportAddressIPv6')
        transportAddress = TransportAddressIPv6(transportAddress)
        if sourceAddress is None:
            sourceAddress = ('::', 0)
        sourceAddress = TransportAddressIPv6(sourceAddress)

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpTargetAddrEntry.name + (9,) + tblIdx, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpTargetAddrEntry.name + (9,) + tblIdx, 'createAndGo'),
        (snmpTargetAddrEntry.name + (1,) + tblIdx, addrName),
        (snmpTargetAddrEntry.name + (2,) + tblIdx, transportDomain),
        (snmpTargetAddrEntry.name + (3,) + tblIdx, transportAddress),
        (snmpTargetAddrEntry.name + (4,) + tblIdx, timeout),
        (snmpTargetAddrEntry.name + (5,) + tblIdx, retryCount),
        (snmpTargetAddrEntry.name + (6,) + tblIdx, tagList),
        (snmpTargetAddrEntry.name + (7,) + tblIdx, params),
        (snmpSourceAddrEntry.name + (1,) + tblIdx, sourceAddress),)
        )

def delTargetAddr(snmpEngine, addrName):
    snmpTargetAddrEntry, snmpSourceAddrEntry, tblIdx = __cookTargetAddrInfo(
        snmpEngine, addrName
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpTargetAddrEntry.name + (9,) + tblIdx, 'destroy'),)
        )

def addTransport(snmpEngine, transportDomain, transport):
    if snmpEngine.transportDispatcher:
        if not transport.isCompatibleWithDispatcher(snmpEngine.transportDispatcher): 
            raise error.PySnmpError('Transport %r is not compatible with dispatcher %r' % (transport, snmpEngine.transportDispatcher))
    else:
        snmpEngine.registerTransportDispatcher(
            transport.protoTransportDispatcher()
        )
        # here we note that we have created transportDispatcher automatically
        snmpEngine.setUserContext(automaticTransportDispatcher=0)
    snmpEngine.transportDispatcher.registerTransport(
        transportDomain, transport
    )
    automaticTransportDispatcher = snmpEngine.getUserContext(
        'automaticTransportDispatcher'
    )
    if automaticTransportDispatcher is not None:
        snmpEngine.setUserContext(
            automaticTransportDispatcher=automaticTransportDispatcher+1
        )

def getTransport(snmpEngine, transportDomain):
    if not snmpEngine.transportDispatcher:
        return
    try:
        return snmpEngine.transportDispatcher.getTransport(transportDomain)
    except error.PySnmpError:
        return
     
def delTransport(snmpEngine, transportDomain):
    if not snmpEngine.transportDispatcher:
        return
    transport = getTransport(snmpEngine, transportDomain)
    snmpEngine.transportDispatcher.unregisterTransport(transportDomain)
    # automatically shutdown automatically created transportDispatcher
    automaticTransportDispatcher = snmpEngine.getUserContext(
        'automaticTransportDispatcher'
    )
    if automaticTransportDispatcher is not None:
        automaticTransportDispatcher -= 1
        snmpEngine.setUserContext(
            automaticTransportDispatcher=automaticTransportDispatcher
        )
        if not automaticTransportDispatcher:
            snmpEngine.transportDispatcher.closeDispatcher()
            snmpEngine.unregisterTransportDispatcher()
            snmpEngine.delUserContext(automaticTransportDispatcher)
    return transport

addSocketTransport = addTransport
delSocketTransport = delTransport

# VACM shortcuts

def addContext(snmpEngine, contextName):
    vacmContextEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
        'SNMP-VIEW-BASED-ACM-MIB', 'vacmContextEntry'
        )
    tblIdx = vacmContextEntry.getInstIdFromIndices(contextName)
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmContextEntry.name + (1,) + tblIdx, contextName),)
        )

def __cookVacmGroupInfo(snmpEngine, securityModel, securityName):
    vacmSecurityToGroupEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
        'SNMP-VIEW-BASED-ACM-MIB', 'vacmSecurityToGroupEntry'
        )
    tblIdx = vacmSecurityToGroupEntry.getInstIdFromIndices(
        securityModel, securityName
        )
    return vacmSecurityToGroupEntry, tblIdx

def addVacmGroup(snmpEngine, groupName, securityModel, securityName):
    vacmSecurityToGroupEntry, tblIdx = __cookVacmGroupInfo(
        snmpEngine, securityModel, securityName
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmSecurityToGroupEntry.name + (5,) + tblIdx, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmSecurityToGroupEntry.name + (5,) + tblIdx, 'createAndGo'),
        (vacmSecurityToGroupEntry.name + (1,) + tblIdx, securityModel),
        (vacmSecurityToGroupEntry.name + (2,) + tblIdx, securityName),
        (vacmSecurityToGroupEntry.name + (3,) + tblIdx, groupName),)
        )

def delVacmGroup(snmpEngine, securityModel, securityName):
    vacmSecurityToGroupEntry, tblIdx = __cookVacmGroupInfo(
        snmpEngine, securityModel, securityName
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmSecurityToGroupEntry.name + (5,) + tblIdx, 'destroy'),)
        )

def __cookVacmAccessInfo(snmpEngine, groupName, contextName, securityModel,
                         securityLevel):
    vacmAccessEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
        'SNMP-VIEW-BASED-ACM-MIB', 'vacmAccessEntry'
        )
    tblIdx = vacmAccessEntry.getInstIdFromIndices(
        groupName, contextName, securityModel, securityLevel
        )
    return vacmAccessEntry, tblIdx

def addVacmAccess(snmpEngine, groupName, contextName, securityModel,
                  securityLevel, prefix, readView, writeView, notifyView):
    vacmAccessEntry, tblIdx = __cookVacmAccessInfo(
        snmpEngine, groupName, contextName, securityModel, securityLevel
        )

    addContext(snmpEngine, contextName) # this is leaky
    
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmAccessEntry.name + (9,) + tblIdx, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmAccessEntry.name + (9,) + tblIdx, 'createAndGo'),
        (vacmAccessEntry.name + (1,) + tblIdx, contextName),
        (vacmAccessEntry.name + (2,) + tblIdx, securityModel),
        (vacmAccessEntry.name + (3,) + tblIdx, securityLevel),
        (vacmAccessEntry.name + (4,) + tblIdx, prefix),
        (vacmAccessEntry.name + (5,) + tblIdx, readView),
        (vacmAccessEntry.name + (6,) + tblIdx, writeView),
        (vacmAccessEntry.name + (7,) + tblIdx, notifyView),)
        )

def delVacmAccess(snmpEngine, groupName, contextName, securityModel,
                  securityLevel):
    vacmAccessEntry, tblIdx = __cookVacmAccessInfo(
        snmpEngine, groupName, contextName, securityModel, securityLevel
        )    
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmAccessEntry.name + (9,) + tblIdx, 'destroy'),)
        )

def __cookVacmViewInfo(snmpEngine, viewName, subTree):
    vacmViewTreeFamilyEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols(
        'SNMP-VIEW-BASED-ACM-MIB', 'vacmViewTreeFamilyEntry'
        )
    tblIdx = vacmViewTreeFamilyEntry.getInstIdFromIndices(
        viewName, subTree
        )
    return vacmViewTreeFamilyEntry, tblIdx

def addVacmView(snmpEngine, viewName, viewType, subTree, mask):
    vacmViewTreeFamilyEntry, tblIdx = __cookVacmViewInfo(
        snmpEngine, viewName, subTree
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmViewTreeFamilyEntry.name + (6,) + tblIdx, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmViewTreeFamilyEntry.name + (6,) + tblIdx, 'createAndGo'),
         (vacmViewTreeFamilyEntry.name + (1,) + tblIdx, viewName),
         (vacmViewTreeFamilyEntry.name + (2,) + tblIdx, subTree),
         (vacmViewTreeFamilyEntry.name + (3,) + tblIdx, mask),
         (vacmViewTreeFamilyEntry.name + (4,) + tblIdx, viewType),)
        )

def delVacmView(snmpEngine, viewName, subTree):
    vacmViewTreeFamilyEntry, tblIdx = __cookVacmViewInfo(
        snmpEngine, viewName, subTree
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((vacmViewTreeFamilyEntry.name + (6,) + tblIdx, 'destroy'),)
        )

# VACM simplicity wrappers

def __cookVacmUserInfo(snmpEngine, securityModel, securityName, securityLevel):
    groupName = 'v-%s-%d' % (hash(securityName), securityModel)
    SnmpSecurityLevel, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-FRAMEWORK-MIB', 'SnmpSecurityLevel')
    securityLevel = SnmpSecurityLevel(securityLevel)
    return ( groupName, securityLevel,
             'r' + groupName, 'w' + groupName, 'n' + groupName )

def addVacmUser(snmpEngine, securityModel, securityName, securityLevel,
                readSubTree=(), writeSubTree=(), notifySubTree=(),
                contextName=null):
    ( groupName, securityLevel,
      readView, writeView, notifyView ) = __cookVacmUserInfo(
        snmpEngine, securityModel, securityName, securityLevel,
        )
    addVacmGroup(
        snmpEngine, groupName, securityModel, securityName
        )
    addVacmAccess(
        snmpEngine, groupName, contextName, securityModel, securityLevel, 1,
        readView, writeView, notifyView
        )
    if readSubTree:
        addVacmView(
            snmpEngine, readView, "included", readSubTree, null,
            )
    if writeSubTree:
        addVacmView(
            snmpEngine, writeView, "included", writeSubTree, null,
            )
    if notifySubTree:
        addVacmView(
            snmpEngine, notifyView, "included", notifySubTree, null,
            )

def delVacmUser(snmpEngine, securityModel, securityName, securityLevel,
                readSubTree=(), writeSubTree=(), notifySubTree=()):
    ( groupName, securityLevel,
      readView, writeView, notifyView ) = __cookVacmUserInfo(
        snmpEngine, securityModel, securityName, securityLevel,
        )
    delVacmGroup(
        snmpEngine, securityModel, securityName
        )
    delVacmAccess(
        snmpEngine, groupName, null, securityModel, securityLevel
        )
    if readSubTree:
        delVacmView(
            snmpEngine, readView, readSubTree
            )
    if writeSubTree:
        delVacmView(
            snmpEngine, writeView, writeSubTree
            )
    if notifySubTree:
        delVacmView(
            snmpEngine, notifyView, notifySubTree
            )

# Obsolete shortcuts for add/delVacmUser() wrappers

def addRoUser(snmpEngine, securityModel, securityName, securityLevel, subTree):
    addVacmUser(
        snmpEngine, securityModel, securityName, securityLevel, subTree
        )

def delRoUser(snmpEngine, securityModel, securityName, securityLevel, subTree):
    delVacmUser(
        snmpEngine, securityModel, securityName, securityLevel, subTree
        )

def addRwUser(snmpEngine, securityModel, securityName, securityLevel, subTree):
    addVacmUser(
        snmpEngine, securityModel, securityName, securityLevel,
        subTree, subTree
        )

def delRwUser(snmpEngine, securityModel, securityName, securityLevel, subTree):
    delVacmUser(
        snmpEngine, securityModel, securityName, securityLevel,
        subTree, subTree
        )

def addTrapUser(snmpEngine,securityModel,securityName,securityLevel,subTree):
    addVacmUser(
        snmpEngine, securityModel, securityName, securityLevel,
        (), (), subTree,
        )

def delTrapUser(snmpEngine,securityModel,securityName,securityLevel,subTree):
    delVacmUser(
        snmpEngine, securityModel, securityName, securityLevel,
        (), (), subTree,
        )

# Notification target setup

def __cookNotificationTargetInfo(snmpEngine, notificationName, paramsName,
                                 filterSubtree=None):
    snmpNotifyEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB', 'snmpNotifyEntry')
    tblIdx1 = snmpNotifyEntry.getInstIdFromIndices(
        notificationName
        )

    snmpNotifyFilterProfileEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB', 'snmpNotifyFilterProfileEntry')
    tblIdx2 = snmpNotifyFilterProfileEntry.getInstIdFromIndices(
        paramsName
        )

    profileName = '%s-filter' % hash(notificationName)
    
    if filterSubtree:
        snmpNotifyFilterEntry, = snmpEngine.msgAndPduDsp.mibInstrumController.mibBuilder.importSymbols('SNMP-NOTIFICATION-MIB', 'snmpNotifyFilterEntry')
        tblIdx3 = snmpNotifyFilterEntry.getInstIdFromIndices(
            profileName, filterSubtree
            )
    else:
        snmpNotifyFilterEntry = tblIdx3 = None

    return ( snmpNotifyEntry, tblIdx1,
             snmpNotifyFilterProfileEntry, tblIdx2, profileName,
             snmpNotifyFilterEntry, tblIdx3 )

def addNotificationTarget(snmpEngine, notificationName, paramsName,
                          transportTag, notifyType=None, filterSubtree=None,
                          filterMask=None, filterType=None):
    ( snmpNotifyEntry, tblIdx1,
      snmpNotifyFilterProfileEntry, tblIdx2, profileName,
      snmpNotifyFilterEntry, tblIdx3 ) = __cookNotificationTargetInfo(
        snmpEngine, notificationName, paramsName, filterSubtree
        )
    
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyEntry.name + (5,) + tblIdx1, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyEntry.name + (5,) + tblIdx1, 'createAndGo'),
         (snmpNotifyEntry.name + (2,) + tblIdx1, transportTag),
         (snmpNotifyEntry.name + (3,) + tblIdx1, notifyType),)
        )

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyFilterProfileEntry.name + (3,) + tblIdx2, 'destroy'),)
        )
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyFilterProfileEntry.name + (3,) + tblIdx2, 'createAndGo'),
         (snmpNotifyFilterProfileEntry.name + (1,) + tblIdx2, profileName),)
        )

    if not snmpNotifyFilterEntry:
        return

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyFilterEntry.name + (5,) + tblIdx3, 'destroy'),)
        )    
    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyFilterEntry.name + (5,) + tblIdx3, 'createAndGo'),
         (snmpNotifyFilterEntry.name + (1,) + tblIdx3, filterSubtree),
         (snmpNotifyFilterEntry.name + (2,) + tblIdx3, filterMask),
         (snmpNotifyFilterEntry.name + (3,) + tblIdx3, filterType),)
        )

def delNotificationTarget(snmpEngine, notificationName, paramsName,
                          filterSubtree=None):
    ( snmpNotifyEntry, tblIdx1,
      snmpNotifyFilterProfileEntry, tblIdx2, profileName,
      snmpNotifyFilterEntry, tblIdx3 ) = __cookNotificationTargetInfo(
        snmpEngine, notificationName, paramsName, filterSubtree
        )

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyEntry.name + (5,) + tblIdx1, 'destroy'),)
        )

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyFilterProfileEntry.name + (3,) + tblIdx2, 'destroy'),)
        )

    if not snmpNotifyFilterEntry:
        return

    snmpEngine.msgAndPduDsp.mibInstrumController.writeVars(
        ((snmpNotifyFilterEntry.name + (5,) + tblIdx3, 'destroy'),)
        )    
    
# rfc3415: A.1
def setInitialVacmParameters(snmpEngine):
    # rfc3415: A.1.1 --> initial-semi-security-configuration
    
    # rfc3415: A.1.2
    addContext(snmpEngine, "")

    # rfc3415: A.1.3
    addVacmGroup(snmpEngine, "initial", 3, "initial")

    # rfc3415: A.1.4
    addVacmAccess(snmpEngine, "initial", "", 3, "noAuthNoPriv", "exact",
                  "restricted", None, "restricted")
    addVacmAccess(snmpEngine, "initial", "", 3, "authNoPriv", "exact",
                  "internet", "internet", "internet")
    addVacmAccess(snmpEngine, "initial", "", 3, "authPriv", "exact",
                  "internet", "internet", "internet")

    # rfc3415: A.1.5 (semi-secure)
    addVacmView(snmpEngine, "internet", "included", (1,3,6,1),"")
    addVacmView(snmpEngine, "restricted", "included", (1,3,6,1,2,1,1),"")
    addVacmView(snmpEngine, "restricted", "included", (1,3,6,1,2,1,11),"")
    addVacmView(snmpEngine, "restricted", "included", (1,3,6,1,6,3,10,2,1),"")
    addVacmView(snmpEngine, "restricted", "included", (1,3,6,1,6,3,11,2,1),"")
    addVacmView(snmpEngine, "restricted", "included", (1,3,6,1,6,3,15,1,1),"")