diff options
Diffstat (limited to 'pysnmp/proto/secmod/rfc3414/service.py')
| -rw-r--r-- | pysnmp/proto/secmod/rfc3414/service.py | 44 |
1 files changed, 39 insertions, 5 deletions
diff --git a/pysnmp/proto/secmod/rfc3414/service.py b/pysnmp/proto/secmod/rfc3414/service.py index 74bdaff9..9fdfe707 100644 --- a/pysnmp/proto/secmod/rfc3414/service.py +++ b/pysnmp/proto/secmod/rfc3414/service.py @@ -16,6 +16,7 @@ from pyasn1.type import namedtype from pyasn1.type import univ from pysnmp import debug +from pysnmp.proto import api from pysnmp.proto import errind from pysnmp.proto import error from pysnmp.proto import rfc1155 @@ -33,6 +34,9 @@ from pysnmp.proto.secmod.rfc3826.priv import aes from pysnmp.proto.secmod.rfc7860.auth import hmacsha2 from pysnmp.smi.error import NoSuchInstanceError +# API to rfc1905 protocol objects +pMod = api.PROTOCOL_MODULES[api.SNMP_VERSION_2C] + # USM security params @@ -304,6 +308,8 @@ class SnmpUSMSecurityModel(AbstractSecurityModel): snmpEngineID = mibBuilder.importSymbols( '__SNMP-FRAMEWORK-MIB', 'snmpEngineID')[0].syntax + msg = globalData + # 3.1.1 if securityStateReference is not None: # 3.1.1a @@ -361,7 +367,7 @@ class SnmpUSMSecurityModel(AbstractSecurityModel): securityEngineID.prettyPrint(), securityName, securityStateReference)) - elif securityName: + elif securityEngineID: # 3.1.1b try: (usmUserName, usmUserSecurityName, usmUserAuthProtocol, @@ -447,7 +453,35 @@ class SnmpUSMSecurityModel(AbstractSecurityModel): raise error.StatusInformation(errorIndication=errind.invalidMsg) else: - # empty username used for engineID discovery + # 4. (start SNMP engine ID discovery) + securityEngineID = securityName = null + securityLevel = 1 + + scopedPDU.setComponentByPosition( + 0, null, verifyConstraints=False, + matchTags=False, matchConstraints=False) + + headerData = msg.getComponentByPosition(1) + + # Clear possible auth&priv flags + headerData.setComponentByPosition( + 2, univ.OctetString(hexValue='00'), verifyConstraints=False, + matchTags=False, matchConstraints=False + ) + + emptyPdu = scopedPDU.getComponentByPosition(2).getComponent() + + # we edit the rest of the structures in-place because they + # are ours for as long as this stack lasts, however PDU + # is more persistent and should not be touched + + emptyPdu = emptyPdu.clone() + pMod.apiPDU.setDefaults(emptyPdu) + + scopedPDU.getComponentByPosition(2).setComponentByType( + emptyPdu.tagSet, emptyPdu, verifyConstraints=False, + matchTags=False, matchConstraints=False) + usmUserName = usmUserSecurityName = null usmUserAuthProtocol = noauth.NoAuth.SERVICE_ID usmUserPrivProtocol = nopriv.NoPriv.SERVICE_ID @@ -456,6 +490,7 @@ class SnmpUSMSecurityModel(AbstractSecurityModel): debug.logger & debug.FLAG_SM and debug.logger( '__generateRequestOrResponseMsg: using blank USM info ' + 'for peer SNMP engine ID discovery ' 'usmUserName "%s" ' 'usmUserSecurityName "%s" ' 'usmUserAuthProtocol "%s" ' @@ -466,9 +501,8 @@ class SnmpUSMSecurityModel(AbstractSecurityModel): usmUserName, usmUserSecurityName, usmUserAuthProtocol, usmUserAuthKeyLocalized, usmUserPrivProtocol, usmUserPrivKeyLocalized, - securityEngineID.prettyPrint(), securityName)) - - msg = globalData + securityEngineID and securityEngineID.prettyPrint(), + securityName)) # 3.1.2 if securityLevel == 3: |