def __init__(self, identityStorage, configFilename=None): """ :param pyndn.IdentityStorage: A class that stores signing identities and certificates. :param str configFilename: A configuration file specifying validation rules and network name settings. """ # use the default configuration where possible # TODO: use environment variable for this, fall back to default path = os.path.dirname(__file__) templateFilename = os.path.join(path, '.default.conf') self._configTemplate = BoostInfoParser() self._configTemplate.read(templateFilename) if configFilename is None: configFilename = templateFilename certificateCache = CertificateCache() super(IotPolicyManager, self).__init__(configFilename, certificateCache) self._identityStorage = identityStorage self.setEnvironmentPrefix(None) self.setTrustRootIdentity(None) self.setDeviceIdentity(None)
def processConfiguration(self, confFile): config = BoostInfoParser() config.read(confFile) # TODO: handle missing configuration, refactor dict representation confObj = dict() try: confObj["identity"] = config["application/identity"][0].value confObj["signer"] = config["application/signer"][0].value except KeyError as e: msg = "Missing key in configuration: " + str(e) print msg return None return confObj
def __init__(self, configFileName, certificateCache=None, searchDepth=5, graceInterval=3000, keyTimestampTtl=3600000, maxTrackedKeys=1000): super(ConfigPolicyManager, self).__init__() if certificateCache is None: self._certificateCache = CertificateCache() else: self._certificateCache = certificateCache self._maxDepth = searchDepth self._keyGraceInterval = graceInterval self._keyTimestampTtl = keyTimestampTtl self._maxTrackedKeys = maxTrackedKeys # stores the fixed-signer certificate name associated with validation rules # so we don't keep loading from files self._fixedCertificateCache = {} # stores the timestamps for each public key used in command interests to avoid # replay attacks # key is public key name, value is last timestamp self._keyTimestamps = {} self.config = BoostInfoParser() self.config.read(configFileName) self.requiresVerification = True self._refreshManager = TrustAnchorRefreshManager() self._loadTrustAnchorCertificates()
def reset(self): """ Reset the certificate cache and other fields to the constructor state. """ self._certificateCache.reset() # stores the fixed-signer certificate name associated with validation rules # so we don't keep loading from files self._fixedCertificateCache = {} # stores the timestamps for each public key used in command interests to avoid # replay attacks # key is public key name, value is last timestamp self._keyTimestamps = {} self.requiresVerification = True self.config = BoostInfoParser() self._refreshManager = TrustAnchorRefreshManager()
def loadApplications(self, directory=None, override=False): if not directory: directory = self._applicationDirectory if override: self._applications.clear() if os.path.exists(directory): for f in os.listdir(directory): fullFileName = os.path.join(directory, f) if os.path.isfile(fullFileName) and f.endswith('.conf'): appName = f.rstrip('.conf') if appName in self._applications and not override: print( "loadApplications: " + appName + " already exists, do nothing for configuration file: " + fullFileName) else: self._applications[appName] = { "tree": BoostInfoParser(), "dataPrefix": [], "version": int(time.time()) } self._applications[appName]["tree"].read(fullFileName) data = Data( Name(self.prefix).append(appName).append( "_schema").appendVersion( self._applications[appName]["version"])) data.setContent( str(self._applications[appName]["tree"].getRoot())) self.signData(data) self._memoryContentCache.add(data) try: validatorTree = self._applications[appName][ "tree"]["validator"][0] for rule in validatorTree["rule"]: self._applications[appName][ "dataPrefix"].append(rule["id"][0].value) # TODO: don't swallow any general exceptions, we want to catch only KeyError (make sure) here except Exception as e: print( "loadApplications parse configuration file " + fullFileName + " : " + str(e)) return
def __init__(self, identityStorage, configFilename=None): """ :param pyndn.IdentityStorage: A class that stores signing identities and certificates. :param str configFilename: A configuration file specifying validation rules and network name settings. """ # use the default configuration where possible # TODO: use environment variable for this, fall back to default path = os.path.dirname(__file__) templateFilename = os.path.join(path, '.default.conf') self._configTemplate = BoostInfoParser() self._configTemplate.read(templateFilename) if configFilename is None: configFilename = templateFilename super(IotPolicyManager, self).__init__(identityStorage, configFilename) self.setEnvironmentPrefix(None) self.setTrustRootIdentity(None) self.setDeviceIdentity(None)
self.stop() else: self.loop.call_soon(self.displayMenu) if __name__ == '__main__': import os import sys nArgs = len(sys.argv) - 1 if nArgs == 0: from pyndn.util.boost_info_parser import BoostInfoParser fileName = os.path.expanduser('~/.ndn/iot_controller.conf') config = BoostInfoParser() config.read(fileName) deviceName = config["device/controllerName"][0].value networkName = config["device/environmentPrefix"][0].value elif nArgs == 2: networkName = sys.argv[1] deviceName = sys.argv[2] else: print('Usage: {} [network-name controller-name]'.format(sys.argv[0])) sys.exit(1) deviceSuffix = Name(deviceName) networkPrefix = Name(networkName) n = IotController(deviceSuffix, networkPrefix) n.start()
class IotPolicyManager(ConfigPolicyManager): def __init__(self, identityStorage, configFilename=None): """ :param pyndn.IdentityStorage: A class that stores signing identities and certificates. :param str configFilename: A configuration file specifying validation rules and network name settings. """ # use the default configuration where possible # TODO: use environment variable for this, fall back to default path = os.path.dirname(__file__) templateFilename = os.path.join(path, '.default.conf') self._configTemplate = BoostInfoParser() self._configTemplate.read(templateFilename) if configFilename is None: configFilename = templateFilename certificateCache = CertificateCache() super(IotPolicyManager, self).__init__(configFilename, certificateCache) self._identityStorage = identityStorage self.setEnvironmentPrefix(None) self.setTrustRootIdentity(None) self.setDeviceIdentity(None) def updateTrustRules(self): """ Should be called after either the device identity, trust root or network prefix is changed. Not called automatically in case they are all changing (typical for bootstrapping). Resets the validation rules if we don't have a trust root or enivronment """ validatorTree = self._configTemplate["validator"][0].clone() if (self._environmentPrefix.size() > 0 and self._trustRootIdentity.size() > 0 and self._deviceIdentity.size() > 0): # don't sneak in a bad identity if not self._environmentPrefix.match(self._deviceIdentity): raise SecurityException("Device identity does not belong to configured network!") environmentUri = self._environmentPrefix.toUri() deviceUri = self._deviceIdentity.toUri() for rule in validatorTree["rule"]: ruleId = rule["id"][0].value if ruleId == 'Certificate Trust': #modify the 'Certificate Trust' rule rule["checker/key-locator/name"][0].value = environmentUri elif ruleId == 'Command Interests': rule["filter/name"][0].value = deviceUri rule["checker/key-locator/name"][0].value = environmentUri #remove old validation rules from config # replace with new validator rules self.config._root.subtrees["validator"] = [validatorTree] def inferSigningIdentity(self, fromName): """ Used to map Data or Interest names to identitites. :param pyndn.Name fromName: The name of a Data or Interest packet """ # works if you have an IotIdentityStorage return self._identityStorage.inferIdentityForName(fromName) def setTrustRootIdentity(self, identityName): """ : param pyndn.Name identityName: The new identity to trust as the controller. """ self._trustRootIdentity = Name(identityName) def getTrustRootIdentity(self): """ : return pyndn.Name: The trusted controller's network name. """ return Name(self._trustRootIdentity) def setEnvironmentPrefix(self, name): """ : param pyndn.Name name: The new root of the network namespace (network prefix) """ self._environmentPrefix = Name(name) def getEnvironmentPrefix(self): """ :return: The root of the network namespace :rtype: pyndn.Name """ return Name(self._environmentPrefix) def getDeviceIdentity(self): return self._deviceIdentity def setDeviceIdentity(self, identity): self._deviceIdentity = Name(identity) def hasRootCertificate(self): """ :return: Whether we've downloaded the controller's network certificate :rtype: boolean """ try: rootCertName = self._identityStorage.getDefaultCertificateNameForIdentity( self._trustRootIdentity) except SecurityException: return False try: rootCert = self._identityStorage.getCertificate(rootCertName) if rootCert is not None: return True finally: return False def hasRootSignedCertificate(self): """ :return: Whether we've received a network certificate from our controller :rtype: boolean """ try: myCertName = self._identityStorage.getDefaultCertificateNameForIdentity( self._deviceIdentity) myCert = self._identityStorage.getCertificate(myCertName) if self._trustRootIdentity.match( myCert.getSignature().getKeyLocator().getKeyName()): return True except SecurityException: pass return False def removeTrustRules(self): """ Resets the network prefix, device identity and trust root identity to empty values """ self.setDeviceIdentity(None) self.setTrustRootIdentity(None) self.setEnvironmentPrefix(None) self.updateTrustRules()
def load(self, filePathOrInputOrConfigSection, inputName=None): """ There are three forms of load: load(filePath) - Load the configuration from the given config file. load(input, inputName) - Load the configuration from the given input string. load(configSection, inputName) - Load the configuration from the given configSection. Each of these forms of load replaces any existing configuration. :param str filePath: The The path of the config file. :param str input: The contents of the configuration rules, with lines separated by NL or CR/NL. :param BoostInfoTree configSection: The configuration section loaded from the config file. It should have one "validator" section. :param str inputName: Used for log messages, etc. """ if type(filePathOrInputOrConfigSection) is str and inputName == None: filePath = filePathOrInputOrConfigSection parser = BoostInfoParser() parser.read(filePath) self.load(parser.getRoot(), filePath) elif (type(filePathOrInputOrConfigSection) is str and type(inputName) is str): input = filePathOrInputOrConfigSection parser = BoostInfoParser() parser.read(input, inputName) self.load(parser.getRoot(), inputName) else: configSection = filePathOrInputOrConfigSection if self._isConfigured: # Reset the previous configuration. self._shouldBypass = False self._dataRules = [] self._interestRules = [] self._validator.resetAnchors() self._validator.resetVerifiedCertificates() self._isConfigured = True validatorList = configSection["validator"] if len(validatorList) != 1: raise ValidatorConfigError( "ValidationPolicyConfig: Expected one validator section") validatorSection = validatorList[0] # Get the rules. ruleList = validatorSection["rule"] for i in range(len(ruleList)): rule = ConfigRule.create(ruleList[i]) if rule.getIsForInterest(): self._interestRules.append(rule) else: self._dataRules.append(rule) # Get the trust anchors. trustAnchorList = validatorSection["trust-anchor"] for i in range(len(trustAnchorList)): self._processConfigTrustAnchor(trustAnchorList[i], inputName)
class ConfigPolicyManager(PolicyManager): """ Create a new ConfigPolicyManager which acts on the rules specified in the configuration file and downloads unknown certificates when necessary. :param string configFileName: The path to the configuration file containing verification rules. :param CertificateCache certificateCache: (optional) A CertificateCache to hold known certificates. :param int searchDepth: (optional) The maximum number of links to follow when verifying a certificate chain. :param int graceInterval: (optional) The window of time difference (in milliseconds) allowed between the timestamp of the first interest signed with a new public key and the validation time. If omitted, use a default value. :param int keyTimestampTtl: (optional) How long a public key's last-used timestamp is kept in the store (milliseconds). If omitted, use a default value. :param int maxTrackedKeys: (optional) The maximum number of public key use timestamps to track. """ def __init__(self, configFileName, certificateCache=None, searchDepth=5, graceInterval=3000, keyTimestampTtl=3600000, maxTrackedKeys=1000): super(ConfigPolicyManager, self).__init__() if certificateCache is None: self._certificateCache = CertificateCache() else: self._certificateCache = certificateCache self._maxDepth = searchDepth self._keyGraceInterval = graceInterval self._keyTimestampTtl = keyTimestampTtl self._maxTrackedKeys = maxTrackedKeys # stores the fixed-signer certificate name associated with validation rules # so we don't keep loading from files self._fixedCertificateCache = {} # stores the timestamps for each public key used in command interests to avoid # replay attacks # key is public key name, value is last timestamp self._keyTimestamps = {} self.config = BoostInfoParser() self.config.read(configFileName) self.requiresVerification = True self._refreshManager = TrustAnchorRefreshManager() self._loadTrustAnchorCertificates() def requireVerify(self, dataOrInterest): """ If the configuration file contains the trust anchor 'any', nothing is verified. """ return self.requiresVerification def checkSigningPolicy(self, dataName, certificateName): """ Override to always indicate that the signing certificate name and data name satisfy the signing policy. :param Name dataName: The name of data to be signed. :param Name certificateName: The name of signing certificate. :return: True to indicate that the signing certificate can be used to sign the data. :rtype: boolean """ return True def skipVerifyAndTrust(self, dataOrInterest): """ If the configuration file contains the trust anchor 'any', nothing is verified. """ return not self.requiresVerification def _loadTrustAnchorCertificates(self): """ The configuration file allows 'trust anchor' certificates to be preloaded. The certificates may also be loaded from a directory, and if the 'refresh' option is set to an interval, the certificates are reloaded at the specified interval """ try: anchors = self.config["validator/trust-anchor"] except KeyError: return for anchor in anchors: typeName = anchor["type"][0].getValue() if typeName == 'file': certID = anchor["file-name"][0].getValue() isPath = True elif typeName == 'base64': certID = anchor["base64-string"][0].getValue() isPath = False elif typeName == "dir": dirName = anchor["dir"][0].getValue() try: refreshPeriodStr = anchor["refresh"][0].getValue() except KeyError: refreshPeriod = 0 else: refreshMatch = re.match('(\d+)([hms])', refreshPeriodStr) if not refreshMatch: refreshPeriod = 0 else: refreshPeriod = int(refreshMatch.group(1)) if refreshMatch.group(2) != 's': refreshPeriod *= 60 if refreshMatch.group(2) != 'm': refreshPeriod *= 60 # Convert refreshPeriod from seconds to milliseconds. self._refreshManager.addDirectory(dirName, refreshPeriod * 1000) continue elif typeName == "any": # this disables all security! self.requiresVerification = False break self._lookupCertificate(certID, isPath) def _checkSignatureMatch(self, signatureName, objectName, rule): """ Once a rule is found to match data or a signed interest, the name in the KeyLocator must satisfy the condition in the 'checker' section of the rule, else the data or interest is rejected. :param Name signatureName: The certificate name from the KeyLocator . :param Name objectName: The name of the data packet or interest. In the case of signed interests, this excludes the timestamp, nonce and signature components. :param BoostInfoTree rule: The rule from the configuration file that matches the data or interest. """ checker = rule['checker'][0] checkerType = checker['type'][0].getValue() if checkerType == 'fixed-signer': signerInfo = checker['signer'][0] signerType = signerInfo['type'][0].getValue() if signerType == 'file': cert = self._lookupCertificate(signerInfo['file-name'][0].getValue(), True) elif signerType == 'base64': cert = self._lookupCertificate(signerInfo['base64-string'][0].getValue(), False) else: return False if cert is None: return False else: return cert.getName().equals(signatureName) elif checkerType == 'hierarchical': # this just means the data/interest name has the signing identity as a prefix # that means everything before 'ksk-?' in the key name identityRegex = '^([^<KEY>]*)<KEY>(<>*)<ksk-.+><ID-CERT>' identityMatch = NdnRegexMatcher.match(identityRegex, signatureName) if identityMatch is not None: identityPrefix = Name(identityMatch.group(1)).append(Name(identityMatch.group(2))) return self._matchesRelation(objectName, identityPrefix, 'is-prefix-of') else: return False elif checkerType == 'customized': keyLocatorInfo = checker['key-locator'][0] # not checking type - only name is supported # is this a simple relation? try: relationType = keyLocatorInfo['relation'][0].getValue() except KeyError: pass else: matchName = Name(keyLocatorInfo['name'][0].getValue()) return self._matchesRelation(signatureName, matchName, relationType) # is this a simple regex? try: keyRegex = keyLocatorInfo['regex'][0].getValue() except KeyError: pass else: return NdnRegexMatcher.match(keyRegex, signatureName) is not None # is this a hyper-relation? try: hyperRelation = keyLocatorInfo['hyper-relation'][0] except KeyError: pass else: try: keyRegex = hyperRelation['k-regex'][0].getValue() keyMatch = NdnRegexMatcher.match(keyRegex, signatureName) keyExpansion = hyperRelation['k-expand'][0].getValue() keyMatchPrefix = keyMatch.expand(keyExpansion) nameRegex = hyperRelation['p-regex'][0].getValue() nameMatch = NdnRegexMatcher.match(nameRegex, objectName) nameExpansion = hyperRelation['p-expand'][0].getValue() nameMatchStr = nameMatch.expand(nameExpansion) relationType = hyperRelation['h-relation'][0].getValue() return self._matchesRelation(Name(nameMatchStr), Name(keyMatchPrefix), relationType) except: pass # unknown type return False def _lookupCertificate(self, certID, isPath): """ This looks up certificates specified as base64-encoded data or file names. These are cached by filename or encoding to avoid repeated reading of files or decoding. """ try: certUri = self._fixedCertificateCache[certID] except KeyError: if isPath: # load the certificate data (base64 encoded IdentityCertificate) cert = TrustAnchorRefreshManager.loadIdentityCertificateFromFile( certID) else: certData = b64decode(certID) cert = IdentityCertificate() cert.wireDecode(certData) certUri = cert.getName()[:-1].toUri() self._fixedCertificateCache[certID] = certUri self._certificateCache.insertCertificate(cert) else: cert = self._certificateCache.getCertificate(Name(certUri)) return cert def _findMatchingRule(self, objName, matchType): """ Search the configuration file for the first rule that matches the data or signed interest name. In the case of interests, the name to match should exclude the timestamp, nonce, and signature components. :param Name objName: The name to be matched. :param string matchType: The rule type to match, "data" or "interest". """ rules = self.config["validator/rule"] for r in rules: if r['for'][0].getValue() == matchType: passed = True try: filters = r['filter'] except KeyError: # no filters means we pass! return r else: for f in filters: # don't check the type - it can only be name for now # we need to see if this is a regex or a relation try: regex = f['regex'][0].getValue() except KeyError: matchRelation = f['relation'][0].getValue() matchUri = f['name'][0].getValue() matchName = Name(matchUri) passed = self._matchesRelation(objName, matchName, matchRelation) else: passed = NdnRegexMatcher.match(regex, objName) is not None if not passed: break if passed: return r return None def _matchesRelation(self, name, matchName, matchRelation): """ Determines if a name satisfies the relation to another name, which can be one of: 'is-prefix-of' - passes if the name is equal to or has the other name as a prefix 'is-strict-prefix-of' - passes if the name has the other name as a prefix, and is not equal 'equal' - passes if the two names are equal """ passed = False if matchRelation == 'is-strict-prefix-of': if matchName.size() == name.size(): passed = False elif matchName.match(name): passed = True elif matchRelation == 'is-prefix-of': if matchName.match(name): passed = True elif matchRelation == 'equal': if matchName.equals(name): passed = True return passed @staticmethod def _extractSignature(dataOrInterest, wireFormat=None): """ Extract the signature information from the interest name or from the data packet. :param dataOrInterest: The object whose signature is needed. :type dataOrInterest: Data or Interest :param WireFormat wireFormat: (optional) The wire format used to decode signature information from the interest name. """ if isinstance(dataOrInterest, Data): return dataOrInterest.getSignature() elif isinstance(dataOrInterest, Interest): if wireFormat is None: # Don't use a default argument since getDefaultWireFormat can change. wireFormat = WireFormat.getDefaultWireFormat() try: signature = wireFormat.decodeSignatureInfoAndValue( dataOrInterest.getName().get(-2).getValue().buf(), dataOrInterest.getName().get(-1).getValue().buf()) except (IndexError, ValueError): return None return signature return None def _interestTimestampIsFresh(self, keyName, timestamp): """ Determine whether the timestamp from the interest is newer than the last use of this key, or within the grace interval on first use. :param Name keyName: The name of the public key used to sign the interest. :paramt int timestamp: The timestamp extracted from the interest name. """ try: lastTimestamp = self._keyTimestamps[keyName.toUri()] except KeyError: now = Common.getNowMilliseconds() notBefore = now - self._keyGraceInterval notAfter = now + self._keyGraceInterval return timestamp > notBefore and timestamp < notAfter else: return timestamp > lastTimestamp def _updateTimestampForKey(self, keyName, timestamp): """ Trim the table size down if necessary, and insert/update the latest interest signing timestamp for the key. Any key which has not been used within the TTL period is purged. If the table is still too large, the oldest key is purged. :param Name keyName: The name of the public key used to sign the interest. :paramt int timestamp: The timestamp extracted from the interest name. """ self._keyTimestamps[keyName.toUri()] = timestamp if len(self._keyTimestamps) >= self._maxTrackedKeys: now = Common.getNowMilliseconds() oldestTimestamp = now oldestKey = None trackedKeys = self._keyTimestamps.keys() for keyUri in trackedKeys: ts = self._keyTimestamps[keyUri] if now - ts > self._keyTimestampTtl: del self._keyTimestamps[keyUri] elif ts < oldestTimestamp: oldestTimestamp = ts oldestKey = keyUri if len(self._keyTimestamps) > self._maxTrackedKeys: # have not removed enough del self._keyTimestamps[oldestKey] def checkVerificationPolicy(self, dataOrInterest, stepCount, onVerified, onVerifyFailed, wireFormat = None): """ If there is a rule matching the data or interest, and the matching certificate is missing, download it. If there is no matching rule, verification fails. Otherwise, verify the signature using the public key in the IdentityStorage. :param dataOrInterest: The Data object or interest with the signature to check. :type dataOrInterest: Data or Interest :param int stepCount: The number of verification steps that have been done, used to track the verification progress. :param onVerified: If the signature is verified, this calls onVerified(dataOrInterest). :type onVerified: function object :param onVerifyFailed: If the signature check fails, this calls onVerifyFailed(dataOrInterest). :type onVerifyFailed: function object :return: None for no further step for looking up a certificate chain. :rtype: ValidationRequest """ if stepCount > self._maxDepth: onVerifyFailed(dataOrInterest) return None signature = self._extractSignature(dataOrInterest, wireFormat) # no signature -> fail if signature is None: onVerifyFailed(dataOrInterest) return None signatureName = signature.getKeyLocator().getKeyName() # no key name in KeyLocator -> fail if signatureName.size() == 0: onVerifyFailed(dataOrInterest) return None objectName = dataOrInterest.getName() matchType = "data" #for command interests, we need to ignore the last 4 components when matching the name if isinstance(dataOrInterest, Interest): objectName = objectName.getPrefix(-4) matchType = "interest" # first see if we can find a rule to match this packet try: matchedRule = self._findMatchingRule(objectName, matchType) except: matchedRule = None # no matching rule -> fail if matchedRule is None: onVerifyFailed(dataOrInterest) return None signatureMatches = self._checkSignatureMatch(signatureName, objectName, matchedRule) if not signatureMatches: onVerifyFailed(dataOrInterest) return None # before we look up keys, refresh any certificate directories self._refreshManager.refreshAnchors() # now finally check that the data or interest was signed correctly # if we don't actually have the certificate yet, create a # ValidationRequest for it foundCert = self._refreshManager.getCertificate(signatureName) if foundCert is None: foundCert = self._certificateCache.getCertificate(signatureName) if foundCert is None: certificateInterest = Interest(signatureName) def onCertificateDownloadComplete(certificate): certificate = IdentityCertificate(certificate) self._certificateCache.insertCertificate(certificate) self.checkVerificationPolicy(dataOrInterest, stepCount+1, onVerified, onVerifyFailed) nextStep = ValidationRequest(certificateInterest, onCertificateDownloadComplete, onVerifyFailed, 2, stepCount+1) return nextStep # for interests, we must check that the timestamp is fresh enough # I do this after (possibly) downloading the certificate to avoid # filling the cache with bad keys if isinstance(dataOrInterest, Interest): keyName = foundCert.getPublicKeyName() timestamp = dataOrInterest.getName().get(-4).toNumber() if not self._interestTimestampIsFresh(keyName, timestamp): onVerifyFailed(dataOrInterest) return None # certificate is known, verify the signature if self._verify(signature, dataOrInterest.wireEncode()): onVerified(dataOrInterest) if isinstance(dataOrInterest, Interest): self._updateTimestampForKey(keyName, timestamp) else: onVerifyFailed(dataOrInterest) def _verify(self, signatureInfo, signedBlob): """ Check the type of signatureInfo to get the KeyLocator. Look in the IdentityStorage for the public key with the name in the KeyLocator and use it to verify the signedBlob. If the public key can't be found, return false. (This is a generalized method which can verify both a Data packet and an interest.) :param Signature signatureInfo: An object of a subclass of Signature, e.g. Sha256WithRsaSignature. :param SignedBlob signedBlob: the SignedBlob with the signed portion to verify. :return: True if the signature verifies, False if not. :rtype: boolean """ signature = signatureInfo if not isinstance(signature, Sha256WithRsaSignature): raise SecurityException( "ConfigPolicyManager: Signature is not Sha256WithRsaSignature.") if (signature.getKeyLocator().getType() == KeyLocatorType.KEYNAME): # Assume the key name is a certificate name. signatureName = signature.getKeyLocator().getKeyName() certificate = self._refreshManager.getCertificate(signatureName) if certificate is None: certificate = self._certificateCache.getCertificate(signatureName) if certificate is None: return False publicKeyDer = certificate.getPublicKeyInfo().getKeyDer() if publicKeyDer.isNull(): # Can't find the public key with the name. return False return self._verifySha256WithRsaSignature( signature, signedBlob, publicKeyDer) else: # Can't find a key to verify. return False
def load(self, filePathOrInputOrConfigSection, inputName = None): """ There are three forms of load: load(filePath) - Load the configuration from the given config file. load(input, inputName) - Load the configuration from the given input string. load(configSection, inputName) - Load the configuration from the given configSection. Each of these forms of load replaces any existing configuration. :param str filePath: The The path of the config file. :param str input: The contents of the configuration rules, with lines separated by NL or CR/NL. :param BoostInfoTree configSection: The configuration section loaded from the config file. It should have one "validator" section. :param str inputName: Used for log messages, etc. """ if type(filePathOrInputOrConfigSection) is str and inputName == None: filePath = filePathOrInputOrConfigSection parser = BoostInfoParser() parser.read(filePath) self.load(parser.getRoot(), filePath) elif (type(filePathOrInputOrConfigSection) is str and type(inputName) is str): input = filePathOrInputOrConfigSection parser = BoostInfoParser() parser.read(input, inputName) self.load(parser.getRoot(), inputName) else: configSection = filePathOrInputOrConfigSection if self._isConfigured: # Reset the previous configuration. self._shouldBypass = False self._dataRules = [] self._interestRules = [] self._validator.resetAnchors() self._validator.resetVerifiedCertificates() self._isConfigured = True validatorList = configSection["validator"] if len(validatorList) != 1: raise ValidatorConfigError( "ValidationPolicyConfig: Expected one validator section") validatorSection = validatorList[0] # Get the rules. ruleList = validatorSection["rule"] for i in range(len(ruleList)): rule = ConfigRule.create(ruleList[i]) if rule.getIsForInterest(): self._interestRules.append(rule) else: self._dataRules.append(rule) # Get the trust anchors. trustAnchorList = validatorSection["trust-anchor"] for i in range(len(trustAnchorList)): self._processConfigTrustAnchor(trustAnchorList[i], inputName)
def updateTrustSchema(self, appName, certName, dataPrefix, publishNew=False): if appName in self._applications: if dataPrefix.toUri() in self._applications[appName]["dataPrefix"]: print("some key is configured for namespace " + dataPrefix.toUri() + " for application " + appName + ". Ignoring this request.") return False else: # TODO: Handle malformed conf where validator tree does not exist validatorNode = self._applications[appName]["tree"][ "validator"][0] else: # This application does not previously exist, we create its trust schema # (and for now, add in static rules for sync data) self._applications[appName] = { "tree": BoostInfoParser(), "dataPrefix": [], "version": 0 } validatorNode = self._applications[appName]["tree"].getRoot( ).createSubtree("validator") trustAnchorNode = validatorNode.createSubtree("trust-anchor") #trustAnchorNode.createSubtree("type", "file") #trustAnchorNode.createSubtree("file-name", os.path.expanduser("~/.ndn/iot/root.cert")) trustAnchorNode.createSubtree("type", "base64") trustAnchorNode.createSubtree( "base64-string", Blob(b64encode(self._rootCertificate.wireEncode().toBytes()), False).toRawStr()) #create cert verification rule # TODO: the idea for this would be, if the cert has /home-prefix/<one-component>/KEY/ksk-*/ID-CERT, then it should be signed by fixed controller(s) # if the cert has /home-prefix/<multiple-components>/KEY/ksk-*/ID-CERT, then it should be checked hierarchically (this is for subdomain support) certRuleNode = validatorNode.createSubtree("rule") certRuleNode.createSubtree("id", "Certs") certRuleNode.createSubtree("for", "data") filterNode = certRuleNode.createSubtree("filter") filterNode.createSubtree("type", "regex") filterNode.createSubtree("regex", "^[^<KEY>]*<KEY><>*<ID-CERT>") checkerNode = certRuleNode.createSubtree("checker") # TODO: wait how did my first hierarchical verifier work? #checkerNode.createSubtree("type", "hierarchical") checkerNode.createSubtree("type", "customized") checkerNode.createSubtree("sig-type", "rsa-sha256") keyLocatorNode = checkerNode.createSubtree("key-locator") keyLocatorNode.createSubtree("type", "name") # We don't put cert version in there keyLocatorNode.createSubtree( "name", Name(self.getDefaultCertificateName()).getPrefix(-1).toUri()) keyLocatorNode.createSubtree("relation", "equal") # Discovery rule: anything that multicasts under my home prefix should be signed, and the signer should have been authorized by root # TODO: This rule as of right now is over-general discoveryRuleNode = validatorNode.createSubtree("rule") discoveryRuleNode.createSubtree("id", "sync-data") discoveryRuleNode.createSubtree("for", "data") filterNode = discoveryRuleNode.createSubtree("filter") filterNode.createSubtree("type", "regex") filterNode.createSubtree("regex", "^[^<MULTICAST>]*<MULTICAST><>*") checkerNode = discoveryRuleNode.createSubtree("checker") # TODO: wait how did my first hierarchical verifier work? #checkerNode.createSubtree("type", "hierarchical") checkerNode.createSubtree("type", "customized") checkerNode.createSubtree("sig-type", "rsa-sha256") keyLocatorNode = checkerNode.createSubtree("key-locator") keyLocatorNode.createSubtree("type", "name") keyLocatorNode.createSubtree("regex", "^[^<KEY>]*<KEY><>*<ID-CERT>") ruleNode = validatorNode.createSubtree("rule") ruleNode.createSubtree("id", dataPrefix.toUri()) ruleNode.createSubtree("for", "data") filterNode = ruleNode.createSubtree("filter") filterNode.createSubtree("type", "name") filterNode.createSubtree("name", dataPrefix.toUri()) filterNode.createSubtree("relation", "is-prefix-of") checkerNode = ruleNode.createSubtree("checker") checkerNode.createSubtree("type", "customized") checkerNode.createSubtree("sig-type", "rsa-sha256") keyLocatorNode = checkerNode.createSubtree("key-locator") keyLocatorNode.createSubtree("type", "name") # We don't put cert version in there keyLocatorNode.createSubtree("name", certName.getPrefix(-1).toUri()) keyLocatorNode.createSubtree("relation", "equal") if not os.path.exists(self._applicationDirectory): os.makedirs(self._applicationDirectory) self._applications[appName]["tree"].write( os.path.join(self._applicationDirectory, appName + ".conf")) self._applications[appName]["dataPrefix"].append(dataPrefix.toUri()) self._applications[appName]["version"] = int(time.time()) if publishNew: # TODO: ideally, this is the trust schema of the application, and does not necessarily carry controller prefix. # We make it carry controller prefix here so that prefix registration / route setup is easier (implementation workaround) data = Data( Name(self.prefix).append(appName).append( "_schema").appendVersion( self._applications[appName]["version"])) data.setContent(str(self._applications[appName]["tree"].getRoot())) self.signData(data) self._memoryContentCache.add(data) return True
self.log.debug(msg) if __name__ == '__main__': import sys import os # todo - should I enforce the suffix 'gateway'? nArgs = len(sys.argv) - 1 if nArgs < 2: from pyndn.util.boost_info_parser import BoostInfoParser fileName = '/usr/local/etc/ndn/iot_controller.conf' if nArgs == 1: fileName = sys.argv[1] try: config = BoostInfoParser() config.read(fileName) except IOError: print('Could not read {}, exiting...'.format(fileName)) sys.exit(1) else: deviceName = config["device/controllerName"][0].value networkName = config["device/environmentPrefix"][0].value elif nArgs == 2: networkName = sys.argv[1] deviceName = sys.argv[2] else: print('Usage: {} [network-name controller-name]'.format(sys.argv[0])) sys.exit(1) try:
class IotPolicyManager(ConfigPolicyManager): def __init__(self, identityStorage, configFilename=None): """ :param pyndn.IdentityStorage: A class that stores signing identities and certificates. :param str configFilename: A configuration file specifying validation rules and network name settings. """ # use the default configuration where possible # TODO: use environment variable for this, fall back to default path = os.path.dirname(__file__) templateFilename = os.path.join(path, '.default.conf') self._configTemplate = BoostInfoParser() self._configTemplate.read(templateFilename) if configFilename is None: configFilename = templateFilename certificateCache = CertificateCache() super(IotPolicyManager, self).__init__(configFilename, certificateCache) self._identityStorage = identityStorage self.setEnvironmentPrefix(None) self.setTrustRootIdentity(None) self.setDeviceIdentity(None) def updateTrustRules(self): """ Should be called after either the device identity, trust root or network prefix is changed. Not called automatically in case they are all changing (typical for bootstrapping). Resets the validation rules if we don't have a trust root or environment """ validatorTree = self._configTemplate["validator"][0].clone() if (self._environmentPrefix.size() > 0 and self._trustRootIdentity.size() > 0 and self._deviceIdentity.size() > 0): # don't sneak in a bad identity if not self._environmentPrefix.match(self._deviceIdentity): raise SecurityException( "Device identity does not belong to configured network!") environmentUri = self._environmentPrefix.toUri() deviceUri = self._deviceIdentity.toUri() for rule in validatorTree["rule"]: ruleId = rule["id"][0].value if ruleId == 'Certificate Trust': #modify the 'Certificate Trust' rule rule["checker/key-locator/name"][0].value = environmentUri elif ruleId == 'Command Interests': rule["filter/name"][0].value = deviceUri rule["checker/key-locator/name"][0].value = environmentUri #debug for adding trust anchor # try: # validatorTree["trust-anchor"][0]["type"][0].value = "base64" # rootCertificate = self._identityStorage.getCertificate(self._identityStorage.getDefaultCertificateNameForIdentity(self._trustRootIdentity)) # validatorTree["trust-anchor"][0]["base64-string"][0].value = Blob(b64encode(rootCertificate.wireEncode().toBytes()), False).toRawStr() # except KeyError as e: # rootCertificate = self._identityStorage.getCertificate(self._identityStorage.getDefaultCertificateNameForIdentity(self._trustRootIdentity)) # treeNode = self.config._root.subtrees["validator"][0].createSubtree("trust-anchor") # # todo: change this! # treeNode.createSubtree("type", "file") # print Blob(b64encode(rootCertificate.wireEncode().toBytes()), False).toRawStr() # treeNode.createSubtree("file-name", "/home/zhehao/.ndn/.iot.root.cert") # self._loadTrustAnchorCertificates() #remove old validation rules from config # replace with new validator rules self.config._root.subtrees["validator"] = [validatorTree] def inferSigningIdentity(self, fromName): """ Used to map Data or Interest names to identitites. :param pyndn.Name fromName: The name of a Data or Interest packet """ # works if you have an IotIdentityStorage return self._identityStorage.inferIdentityForName(fromName) def setTrustRootIdentity(self, identityName): """ : param pyndn.Name identityName: The new identity to trust as the controller. """ self._trustRootIdentity = Name(identityName) def getTrustRootIdentity(self): """ : return pyndn.Name: The trusted controller's network name. """ return Name(self._trustRootIdentity) def setEnvironmentPrefix(self, name): """ : param pyndn.Name name: The new root of the network namespace (network prefix) """ self._environmentPrefix = Name(name) def getEnvironmentPrefix(self): """ :return: The root of the network namespace :rtype: pyndn.Name """ return Name(self._environmentPrefix) def getDeviceIdentity(self): return self._deviceIdentity def setDeviceIdentity(self, identity): self._deviceIdentity = Name(identity) def hasRootCertificate(self): """ :return: Whether we've downloaded the controller's network certificate :rtype: boolean """ try: rootCertName = self._identityStorage.getDefaultCertificateNameForIdentity( self._trustRootIdentity) except SecurityException: return False try: rootCert = self._identityStorage.getCertificate(rootCertName) if rootCert is not None: return True finally: return False def hasRootSignedCertificate(self): """ :return: Whether we've received a network certificate from our controller :rtype: boolean """ try: myCertName = self._identityStorage.getDefaultCertificateNameForIdentity( self._deviceIdentity) myCert = self._identityStorage.getCertificate(myCertName) if self._trustRootIdentity.match( myCert.getSignature().getKeyLocator().getKeyName()): return True except SecurityException: pass return False def removeTrustRules(self): """ Resets the network prefix, device identity and trust root identity to empty values """ self.setDeviceIdentity(None) self.setTrustRootIdentity(None) self.setEnvironmentPrefix(None) self.updateTrustRules()
class ConfigPolicyManager(PolicyManager): """ Create a new ConfigPolicyManager which will act on the rules specified in the configuration and download unknown certificates when necessary. :param str configFileName: (optional) If not null or empty, the path to the configuration file containing verification rules. Otherwise, you should separately call load(). :param CertificateCache certificateCache: (optional) A CertificateCache to hold known certificates. :param int searchDepth: (optional) The maximum number of links to follow when verifying a certificate chain. :param int graceInterval: (optional) The window of time difference (in milliseconds) allowed between the timestamp of the first interest signed with a new public key and the validation time. If omitted, use a default value. :param int keyTimestampTtl: (optional) How long a public key's last-used timestamp is kept in the store (milliseconds). If omitted, use a default value. :param int maxTrackedKeys: (optional) The maximum number of public key use timestamps to track. """ def __init__(self, configFileName=None, certificateCache=None, searchDepth=5, graceInterval=3000, keyTimestampTtl=3600000, maxTrackedKeys=1000): super(ConfigPolicyManager, self).__init__() if certificateCache is None: self._certificateCache = CertificateCache() else: self._certificateCache = certificateCache self._maxDepth = searchDepth self._keyGraceInterval = graceInterval self._keyTimestampTtl = keyTimestampTtl self._maxTrackedKeys = maxTrackedKeys self.reset() if configFileName != None and configFileName != "": self.load(configFileName) def reset(self): """ Reset the certificate cache and other fields to the constructor state. """ self._certificateCache.reset() # stores the fixed-signer certificate name associated with validation rules # so we don't keep loading from files self._fixedCertificateCache = {} # stores the timestamps for each public key used in command interests to avoid # replay attacks # key is public key name, value is last timestamp self._keyTimestamps = {} self.requiresVerification = True self.config = BoostInfoParser() self._refreshManager = TrustAnchorRefreshManager() def load(self, configFileNameOrInput, inputName=None): """ Call reset() and load the configuration rules from the file name or the input string. There are two forms: load(configFileName) reads configFileName from the file system. load(input, inputName) reads from the input, in which case inputName is used only for log messages, etc. :param str configFileName: The path to the file containing configuration rules. :param str input: The contents of the configuration rules, with lines separated by NL or CR/NL. :param str inputName: Use with input for log messages, etc. """ self.reset() self.config.read(configFileNameOrInput, inputName) self._loadTrustAnchorCertificates() def requireVerify(self, dataOrInterest): """ If the configuration file contains the trust anchor 'any', nothing is verified. """ return self.requiresVerification def checkSigningPolicy(self, dataName, certificateName): """ Override to always indicate that the signing certificate name and data name satisfy the signing policy. :param Name dataName: The name of data to be signed. :param Name certificateName: The name of signing certificate. :return: True to indicate that the signing certificate can be used to sign the data. :rtype: boolean """ return True def skipVerifyAndTrust(self, dataOrInterest): """ If the configuration file contains the trust anchor 'any', nothing is verified. """ return not self.requiresVerification def _loadTrustAnchorCertificates(self): """ The configuration file allows 'trust anchor' certificates to be preloaded. The certificates may also be loaded from a directory, and if the 'refresh' option is set to an interval, the certificates are reloaded at the specified interval """ try: anchors = self.config["validator/trust-anchor"] except KeyError: return for anchor in anchors: typeName = anchor["type"][0].getValue() if typeName == 'file': certID = anchor["file-name"][0].getValue() isPath = True elif typeName == 'base64': certID = anchor["base64-string"][0].getValue() isPath = False elif typeName == "dir": dirName = anchor["dir"][0].getValue() try: refreshPeriodStr = anchor["refresh"][0].getValue() except KeyError: refreshPeriod = 0 else: refreshMatch = re.match('(\d+)([hms])', refreshPeriodStr) if not refreshMatch: refreshPeriod = 0 else: refreshPeriod = int(refreshMatch.group(1)) if refreshMatch.group(2) != 's': refreshPeriod *= 60 if refreshMatch.group(2) != 'm': refreshPeriod *= 60 # Convert refreshPeriod from seconds to milliseconds. self._refreshManager.addDirectory(dirName, refreshPeriod * 1000) continue elif typeName == "any": # this disables all security! self.requiresVerification = False break self._lookupCertificate(certID, isPath) def _checkSignatureMatch(self, signatureName, objectName, rule, failureReason): """ Once a rule is found to match data or a signed interest, the name in the KeyLocator must satisfy the condition in the 'checker' section of the rule, else the data or interest is rejected. :param Name signatureName: The certificate name from the KeyLocator . :param Name objectName: The name of the data packet or interest. In the case of signed interests, this excludes the timestamp, nonce and signature components. :param BoostInfoTree rule: The rule from the configuration file that matches the data or interest. :param Array<str> failureReason: If verification fails, set failureReason[0] to the failure reason string. :return: True if matches. :rtype: bool """ checker = rule['checker'][0] checkerType = checker['type'][0].getValue() if checkerType == 'fixed-signer': signerInfo = checker['signer'][0] signerType = signerInfo['type'][0].getValue() if signerType == 'file': cert = self._lookupCertificate( signerInfo['file-name'][0].getValue(), True) if cert is None: failureReason[0] = ( "Can't find fixed-signer certificate file: " + signerInfo['file-name'][0].getValue()) return False elif signerType == 'base64': cert = self._lookupCertificate( signerInfo['base64-string'][0].getValue(), False) if cert is None: failureReason[0] = ( "Can't find fixed-signer certificate base64: " + signerInfo['base64-string'][0].getValue()) return False else: failureReason[0] = ("Unrecognized fixed-signer signerType: " + signerType) return False if cert.getName().equals(signatureName): return True else: failureReason[0] = ("fixed-signer cert name \"" + cert.getName().toUri() + "\" does not equal signatureName \"" + signatureName.toUri() + "\"") return False elif checkerType == 'hierarchical': # this just means the data/interest name has the signing identity as a prefix # that means everything before 'ksk-?' in the key name identityRegex = '^([^<KEY>]*)<KEY>(<>*)<ksk-.+><ID-CERT>' identityMatch = NdnRegexMatcher.match(identityRegex, signatureName) if identityMatch is not None: identityPrefix = Name(identityMatch.group(1)).append( Name(identityMatch.group(2))) if self._matchesRelation(objectName, identityPrefix, 'is-prefix-of'): return True else: failureReason[0] = ("The hierarchical objectName \"" + objectName.toUri() + "\" is not a prefix of \"" + identityPrefix.toUri() + "\"") return False else: failureReason[0] = ("The hierarchical identityRegex \"" + identityRegex + "\" does not match signatureName \"" + signatureName.toUri() + "\"") return False elif checkerType == 'customized': keyLocatorInfo = checker['key-locator'][0] # not checking type - only name is supported # is this a simple relation? try: relationType = keyLocatorInfo['relation'][0].getValue() except KeyError: pass else: matchName = Name(keyLocatorInfo['name'][0].getValue()) if self._matchesRelation(signatureName, matchName, relationType): return True else: failureReason[0] = ("The custom signatureName \"" + signatureName.toUri() + "\" does not match matchName \"" + matchName.toUri() + "\" using relation " + relationType) return False # is this a simple regex? try: keyRegex = keyLocatorInfo['regex'][0].getValue() except KeyError: pass else: if NdnRegexMatcher.match(keyRegex, signatureName) is not None: return True else: failureReason[0] = ( "The custom signatureName \"" + signatureName.toUri() + "\" does not regex match simpleKeyRegex \"" + keyRegex + "\"") return False # is this a hyper-relation? try: hyperRelation = keyLocatorInfo['hyper-relation'][0] except KeyError: pass else: keyRegex = hyperRelation.getFirstValue('k-regex') keyExpansion = hyperRelation.getFirstValue('k-expand') nameRegex = hyperRelation.getFirstValue('p-regex') nameExpansion = hyperRelation.getFirstValue('p-expand') relationType = hyperRelation.getFirstValue('h-relation') if (keyRegex != None and keyExpansion != None and nameRegex != None and nameExpansion != None and relationType != None): keyMatch = NdnRegexMatcher.match(keyRegex, signatureName) if keyMatch == None: failureReason[0] = ( "The custom hyper-relation signatureName \"" + signatureName.toUri() + "\" does not match the keyRegex \"" + keyRegex + "\"") return False keyMatchPrefix = keyMatch.expand(keyExpansion) nameMatch = NdnRegexMatcher.match(nameRegex, objectName) if nameMatch == None: failureReason[0] = ( "The custom hyper-relation objectName \"" + objectName.toUri() + "\" does not match the nameRegex \"" + nameRegex + "\"") return False nameMatchStr = nameMatch.expand(nameExpansion) if self._matchesRelation(Name(nameMatchStr), Name(keyMatchPrefix), relationType): return True else: failureReason[0] = ( "The custom hyper-relation nameMatch \"" + nameMatchStr + "\" does not match the keyMatchPrefix \"" + keyMatchPrefix + "\" using relation " + relationType) return False failureReason[0] = "Unrecognized checkerType: " + checkerType return False def _lookupCertificate(self, certID, isPath): """ This looks up certificates specified as base64-encoded data or file names. These are cached by filename or encoding to avoid repeated reading of files or decoding. :return: The certificate object, or None if not found. :rtype: IdentityCertificate """ try: certUri = self._fixedCertificateCache[certID] except KeyError: if isPath: # load the certificate data (base64 encoded IdentityCertificate) cert = TrustAnchorRefreshManager.loadIdentityCertificateFromFile( certID) else: certData = b64decode(certID) cert = IdentityCertificate() cert.wireDecode(Blob(certData, False)) certUri = cert.getName()[:-1].toUri() self._fixedCertificateCache[certID] = certUri self._certificateCache.insertCertificate(cert) else: cert = self._certificateCache.getCertificate(Name(certUri)) return cert def _findMatchingRule(self, objName, matchType): """ Search the configuration file for the first rule that matches the data or signed interest name. In the case of interests, the name to match should exclude the timestamp, nonce, and signature components. :param Name objName: The name to be matched. :param string matchType: The rule type to match, "data" or "interest". """ rules = self.config["validator/rule"] for r in rules: if r['for'][0].getValue() == matchType: passed = True try: filters = r['filter'] except KeyError: # no filters means we pass! return r else: for f in filters: # don't check the type - it can only be name for now # we need to see if this is a regex or a relation try: regex = f['regex'][0].getValue() except KeyError: matchRelation = f['relation'][0].getValue() matchUri = f['name'][0].getValue() matchName = Name(matchUri) passed = self._matchesRelation( objName, matchName, matchRelation) else: passed = NdnRegexMatcher.match(regex, objName) is not None if not passed: break if passed: return r return None @staticmethod def _matchesRelation(name, matchName, matchRelation): """ Determines if a name satisfies the relation to another name, which can be one of: 'is-prefix-of' - passes if the name is equal to or has the other name as a prefix 'is-strict-prefix-of' - passes if the name has the other name as a prefix, and is not equal 'equal' - passes if the two names are equal """ passed = False if matchRelation == 'is-strict-prefix-of': if matchName.size() == name.size(): passed = False elif matchName.match(name): passed = True elif matchRelation == 'is-prefix-of': if matchName.match(name): passed = True elif matchRelation == 'equal': if matchName.equals(name): passed = True return passed @staticmethod def _extractSignature(dataOrInterest, wireFormat=None): """ Extract the signature information from the interest name or from the data packet. :param dataOrInterest: The object whose signature is needed. :type dataOrInterest: Data or Interest :param WireFormat wireFormat: (optional) The wire format used to decode signature information from the interest name. """ if isinstance(dataOrInterest, Data): return dataOrInterest.getSignature() elif isinstance(dataOrInterest, Interest): if wireFormat is None: # Don't use a default argument since getDefaultWireFormat can change. wireFormat = WireFormat.getDefaultWireFormat() try: signature = wireFormat.decodeSignatureInfoAndValue( dataOrInterest.getName().get(-2).getValue().buf(), dataOrInterest.getName().get(-1).getValue().buf(), False) except (IndexError, ValueError): return None return signature return None def _interestTimestampIsFresh(self, keyName, timestamp, failureReason): """ Determine whether the timestamp from the interest is newer than the last use of this key, or within the grace interval on first use. :param Name keyName: The name of the public key used to sign the interest. :paramt int timestamp: The timestamp extracted from the interest name. :param Array<str> failureReason: If verification fails, set failureReason[0] to the failure reason string. """ try: lastTimestamp = self._keyTimestamps[keyName.toUri()] except KeyError: now = Common.getNowMilliseconds() notBefore = now - self._keyGraceInterval notAfter = now + self._keyGraceInterval if not (timestamp > notBefore and timestamp < notAfter): return False failureReason[0] = ( "The command interest timestamp is not within the first use grace period of " + str(self._keyGraceInterval) + " milliseconds.") else: return True else: if timestamp <= lastTimestamp: failureReason[0] = ( "The command interest timestamp is not newer than the previous timestamp" ) return False else: return True def _updateTimestampForKey(self, keyName, timestamp): """ Trim the table size down if necessary, and insert/update the latest interest signing timestamp for the key. Any key which has not been used within the TTL period is purged. If the table is still too large, the oldest key is purged. :param Name keyName: The name of the public key used to sign the interest. :paramt int timestamp: The timestamp extracted from the interest name. """ self._keyTimestamps[keyName.toUri()] = timestamp if len(self._keyTimestamps) >= self._maxTrackedKeys: now = Common.getNowMilliseconds() oldestTimestamp = now oldestKey = None trackedKeys = self._keyTimestamps.keys() for keyUri in trackedKeys: ts = self._keyTimestamps[keyUri] if now - ts > self._keyTimestampTtl: del self._keyTimestamps[keyUri] elif ts < oldestTimestamp: oldestTimestamp = ts oldestKey = keyUri if len(self._keyTimestamps) > self._maxTrackedKeys: # have not removed enough del self._keyTimestamps[oldestKey] def checkVerificationPolicy(self, dataOrInterest, stepCount, onVerified, onValidationFailed, wireFormat=None): """ If there is a rule matching the data or interest, and the matching certificate is missing, download it. If there is no matching rule, verification fails. Otherwise, verify the signature using the public key in the IdentityStorage. :param dataOrInterest: The Data object or interest with the signature to check. :type dataOrInterest: Data or Interest :param int stepCount: The number of verification steps that have been done, used to track the verification progress. :param onVerified: If the signature is verified, this calls onVerified(dataOrInterest). NOTE: The library will log any exceptions raised by this callback, but for better error handling the callback should catch and properly handle any exceptions. :type onVerified: function object :param onValidationFailed: If the signature check fails, this calls onValidationFailed(dataOrInterest, reason). NOTE: The library will log any exceptions raised by this callback, but for better error handling the callback should catch and properly handle any exceptions. :type onValidationFailed: function object :return: None for no further step for looking up a certificate chain. :rtype: ValidationRequest """ if stepCount > self._maxDepth: try: onValidationFailed( dataOrInterest, "The verification stepCount " + stepCount + " exceeded the maxDepth " + self._maxDepth) except: logging.exception("Error in onValidationFailed") return None signature = self._extractSignature(dataOrInterest, wireFormat) # no signature -> fail if signature is None: try: onValidationFailed( dataOrInterest, "Cannot extract the signature from " + dataOrInterest.getName().toUri()) except: logging.exception("Error in onValidationFailed") return None if not KeyLocator.canGetFromSignature(signature): # We only support signature types with key locators. try: onValidationFailed( dataOrInterest, "The signature type does not support a KeyLocator") except: logging.exception("Error in onValidationFailed") return None keyLocator = None try: keyLocator = KeyLocator.getFromSignature(signature) except Exception as ex: # No key locator -> fail. try: onValidationFailed( dataOrInterest, "Error in KeyLocator.getFromSignature: " + str(ex)) except: logging.exception("Error in onValidationFailed") return None signatureName = keyLocator.getKeyName() # no key name in KeyLocator -> fail if signatureName.size() == 0: try: onValidationFailed( dataOrInterest, "The signature KeyLocator doesn't have a key name") except: logging.exception("Error in onValidationFailed") return None objectName = dataOrInterest.getName() matchType = "data" #for command interests, we need to ignore the last 4 components when matching the name if isinstance(dataOrInterest, Interest): objectName = objectName.getPrefix(-4) matchType = "interest" # first see if we can find a rule to match this packet try: matchedRule = self._findMatchingRule(objectName, matchType) except: matchedRule = None # no matching rule -> fail if matchedRule is None: try: onValidationFailed( dataOrInterest, "No matching rule found for " + objectName.toUri()) except: logging.exception("Error in onValidationFailed") return None failureReason = ["unknown"] signatureMatches = self._checkSignatureMatch(signatureName, objectName, matchedRule, failureReason) if not signatureMatches: try: onValidationFailed(dataOrInterest, failureReason[0]) except: logging.exception("Error in onValidationFailed") return None # before we look up keys, refresh any certificate directories self._refreshManager.refreshAnchors() # now finally check that the data or interest was signed correctly # if we don't actually have the certificate yet, create a # ValidationRequest for it foundCert = self._refreshManager.getCertificate(signatureName) if foundCert is None: foundCert = self._certificateCache.getCertificate(signatureName) if foundCert is None: certificateInterest = Interest(signatureName) def onCertificateDownloadComplete(data): try: certificate = IdentityCertificate(data) except: try: onValidationFailed( dataOrInterest, "Cannot decode certificate " + data.getName().toUri()) except: logging.exception("Error in onValidationFailed") return None self._certificateCache.insertCertificate(certificate) self.checkVerificationPolicy(dataOrInterest, stepCount + 1, onVerified, onValidationFailed) nextStep = ValidationRequest(certificateInterest, onCertificateDownloadComplete, onValidationFailed, 2, stepCount + 1) return nextStep # for interests, we must check that the timestamp is fresh enough # I do this after (possibly) downloading the certificate to avoid # filling the cache with bad keys if isinstance(dataOrInterest, Interest): keyName = foundCert.getPublicKeyName() timestamp = dataOrInterest.getName().get(-4).toNumber() if not self._interestTimestampIsFresh(keyName, timestamp, failureReason): try: onValidationFailed(dataOrInterest, failureReason[0]) except: logging.exception("Error in onValidationFailed") return None # certificate is known, verify the signature if self._verify(signature, dataOrInterest.wireEncode(), failureReason): try: onVerified(dataOrInterest) except: logging.exception("Error in onVerified") if isinstance(dataOrInterest, Interest): self._updateTimestampForKey(keyName, timestamp) else: try: onValidationFailed(dataOrInterest, failureReason[0]) except: logging.exception("Error in onValidationFailed") def _verify(self, signatureInfo, signedBlob, failureReason): """ Check the type of signatureInfo to get the KeyLocator. Look in the IdentityStorage for the public key with the name in the KeyLocator and use it to verify the signedBlob. If the public key can't be found, return false. (This is a generalized method which can verify both a Data packet and an interest.) :param Signature signatureInfo: An object of a subclass of Signature, e.g. Sha256WithRsaSignature. :param SignedBlob signedBlob: the SignedBlob with the signed portion to verify. :param Array<str> failureReason: If verification fails, set failureReason[0] to the failure reason string. :return: True if the signature verifies, False if not. :rtype: boolean """ # We have already checked once that there is a key locator. keyLocator = KeyLocator.getFromSignature(signatureInfo) if (keyLocator.getType() == KeyLocatorType.KEYNAME): # Assume the key name is a certificate name. signatureName = keyLocator.getKeyName() certificate = self._refreshManager.getCertificate(signatureName) if certificate is None: certificate = self._certificateCache.getCertificate( signatureName) if certificate is None: failureReason[0] = ("Cannot find a certificate with name " + signatureName.toUri()) return False publicKeyDer = certificate.getPublicKeyInfo().getKeyDer() if publicKeyDer.isNull(): # We don't expect this to happen. failureReason[0] = ( "There is no public key in the certificate with name " + certificate.getName().toUri()) return False if self.verifySignature(signatureInfo, signedBlob, publicKeyDer): return True else: failureReason[0] = ( "The signature did not verify with the given public key") return False else: failureReason[0] = "The KeyLocator does not have a key name" return False
class ConfigPolicyManager(PolicyManager): """ Create a new ConfigPolicyManager which will act on the rules specified in the configuration and download unknown certificates when necessary. If certificateCache is a CertificateCache (or omitted) this creates a security v1 PolicyManager to verify certificates in format v1. To verify certificates in format v2, use a CertificateCacheV2 for the certificateCache. :param str configFileName: (optional) If not None or empty, the path to the configuration file containing verification rules. Otherwise, you should separately call load(). :param certificateCache: (optional) A CertificateCache to hold known certificates. If certificateCache is a CertificateCache (or omitted or None) this creates a security v1 PolicyManager to verify certificates in format v1. If this is a CertificateCacheV2, verify certificates in format v2. If omitted or None, create an internal v1 CertificateCache. :type certificateCache: CertificateCache or CertificateCacheV2 :param int searchDepth: (optional) The maximum number of links to follow when verifying a certificate chain. :param int graceInterval: (optional) The window of time difference (in milliseconds) allowed between the timestamp of the first interest signed with a new public key and the validation time. If omitted, use a default value. :param int keyTimestampTtl: (optional) How long a public key's last-used timestamp is kept in the store (milliseconds). If omitted, use a default value. :param int maxTrackedKeys: (optional) The maximum number of public key use timestamps to track. """ def __init__(self, configFileName = None, certificateCache = None, searchDepth=5, graceInterval=3000, keyTimestampTtl=3600000, maxTrackedKeys=1000): super(ConfigPolicyManager, self).__init__() if certificateCache is None: certificateCache = CertificateCache() # _certificateCacheV2 will be replaced below, but set it here to make pylint happy. self._certificateCacheV2 = CertificateCacheV2() if isinstance(certificateCache, CertificateCache): self._isSecurityV1 = True self._certificateCache = certificateCache self._certificateCacheV2 = None else: self._isSecurityV1 = False self._certificateCache = None self._certificateCacheV2 = certificateCache self._maxDepth = searchDepth self._keyGraceInterval = graceInterval self._keyTimestampTtl = keyTimestampTtl self._maxTrackedKeys = maxTrackedKeys self.reset() if configFileName != None and configFileName != "": self.load(configFileName) def reset(self): """ Reset the certificate cache and other fields to the constructor state. """ if self._isSecurityV1: self._certificateCache.reset() else: self._certificateCacheV2.clear() # stores the fixed-signer certificate name associated with validation rules # so we don't keep loading from files self._fixedCertificateCache = {} # stores the timestamps for each public key used in command interests to avoid # replay attacks # key is public key name, value is last timestamp self._keyTimestamps = {} self.requiresVerification = True self.config = BoostInfoParser() self._refreshManager = TrustAnchorRefreshManager(self._isSecurityV1) def load(self, configFileNameOrInput, inputName = None): """ Call reset() and load the configuration rules from the file name or the input string. There are two forms: load(configFileName) reads configFileName from the file system. load(input, inputName) reads from the input, in which case inputName is used only for log messages, etc. :param str configFileName: The path to the file containing configuration rules. :param str input: The contents of the configuration rules, with lines separated by NL or CR/NL. :param str inputName: Use with input for log messages, etc. """ self.reset() self.config.read(configFileNameOrInput, inputName) self._loadTrustAnchorCertificates() def requireVerify(self, dataOrInterest): """ If the configuration file contains the trust anchor 'any', nothing is verified. """ return self.requiresVerification def checkSigningPolicy(self, dataName, certificateName): """ Override to always indicate that the signing certificate name and data name satisfy the signing policy. :param Name dataName: The name of data to be signed. :param Name certificateName: The name of signing certificate. :return: True to indicate that the signing certificate can be used to sign the data. :rtype: boolean """ return True def skipVerifyAndTrust(self, dataOrInterest): """ If the configuration file contains the trust anchor 'any', nothing is verified. """ return not self.requiresVerification def _loadTrustAnchorCertificates(self): """ The configuration file allows 'trust anchor' certificates to be preloaded. The certificates may also be loaded from a directory, and if the 'refresh' option is set to an interval, the certificates are reloaded at the specified interval """ try: anchors = self.config["validator/trust-anchor"] except KeyError: return for anchor in anchors: typeName = anchor["type"][0].getValue() if typeName == 'file': certID = anchor["file-name"][0].getValue() isPath = True elif typeName == 'base64': certID = anchor["base64-string"][0].getValue() isPath = False elif typeName == "dir": dirName = anchor["dir"][0].getValue() try: refreshPeriodStr = anchor["refresh"][0].getValue() except KeyError: refreshPeriod = 0 else: refreshMatch = re.match('(\\d+)([hms])', refreshPeriodStr) if not refreshMatch: refreshPeriod = 0 else: refreshPeriod = int(refreshMatch.group(1)) if refreshMatch.group(2) != 's': refreshPeriod *= 60 if refreshMatch.group(2) != 'm': refreshPeriod *= 60 # Convert refreshPeriod from seconds to milliseconds. self._refreshManager.addDirectory(dirName, refreshPeriod * 1000) continue elif typeName == "any": # this disables all security! self.requiresVerification = False break if self._isSecurityV1: self._lookupCertificate(certID, isPath) else: self._lookupCertificateV2(certID, isPath) def _checkSignatureMatch(self, signatureName, objectName, rule, failureReason): """ Once a rule is found to match data or a signed interest, the name in the KeyLocator must satisfy the condition in the 'checker' section of the rule, else the data or interest is rejected. :param Name signatureName: The certificate name from the KeyLocator . :param Name objectName: The name of the data packet or interest. In the case of signed interests, this excludes the timestamp, nonce and signature components. :param BoostInfoTree rule: The rule from the configuration file that matches the data or interest. :param Array<str> failureReason: If verification fails, set failureReason[0] to the failure reason string. :return: True if matches. :rtype: bool """ checker = rule['checker'][0] checkerType = checker['type'][0].getValue() if checkerType == 'fixed-signer': signerInfo = checker['signer'][0] signerType = signerInfo['type'][0].getValue() if signerType == 'file': if self._isSecurityV1: cert = self._lookupCertificate( signerInfo['file-name'][0].getValue(), True) if cert is None: failureReason[0] = ( "Can't find fixed-signer certificate file: " + signerInfo['file-name'][0].getValue()) return False else: cert = self._lookupCertificateV2( signerInfo['file-name'][0].getValue(), True) if cert is None: failureReason[0] = ( "Can't find fixed-signer certificate file: " + signerInfo['file-name'][0].getValue()) return False elif signerType == 'base64': if self._isSecurityV1: cert = self._lookupCertificate( signerInfo['base64-string'][0].getValue(), False) if cert is None: failureReason[0] = ( "Can't find fixed-signer certificate base64: " + signerInfo['base64-string'][0].getValue()) return False else: cert = self._lookupCertificateV2( signerInfo['base64-string'][0].getValue(), False) if cert is None: failureReason[0] = ( "Can't find fixed-signer certificate base64: " + signerInfo['base64-string'][0].getValue()) return False else: failureReason[0] = ("Unrecognized fixed-signer signerType: " + signerType) return False if cert.getName().equals(signatureName): return True else: failureReason[0] = ("fixed-signer cert name \"" + cert.getName().toUri() + "\" does not equal signatureName \"" + signatureName.toUri() + "\"") return False elif checkerType == 'hierarchical': # this just means the data/interest name has the signing identity as a prefix # that means everything before 'ksk-?' in the key name identityRegex = '^([^<KEY>]*)<KEY>(<>*)<ksk-.+><ID-CERT>' identityMatch = NdnRegexTopMatcher(identityRegex) if identityMatch.match(signatureName): identityPrefix = identityMatch.expand("\\1").append( identityMatch.expand("\\2")) if self._matchesRelation(objectName, identityPrefix, 'is-prefix-of'): return True else: failureReason[0] = ("The hierarchical objectName \"" + objectName.toUri() + "\" is not a prefix of \"" + identityPrefix.toUri() + "\"") return False if not self._isSecurityV1: # Check for a security v2 key name. identityRegex2 = "^(<>*)<KEY><>$" identityMatch2 = NdnRegexTopMatcher(identityRegex2) if identityMatch2.match(signatureName): identityPrefix = identityMatch2.expand("\\1") if self._matchesRelation(objectName, identityPrefix, 'is-prefix-of'): return True else: failureReason[0] = ("The hierarchical objectName \"" + objectName.toUri() + "\" is not a prefix of \"" + identityPrefix.toUri() + "\"") return False failureReason[0] = ("The hierarchical identityRegex \"" + identityRegex + "\" does not match signatureName \"" + signatureName.toUri() + "\"") return False elif checkerType == 'customized': keyLocatorInfo = checker['key-locator'][0] # not checking type - only name is supported # is this a simple relation? relationType = keyLocatorInfo.getFirstValue("relation") if relationType != None: matchName = Name(keyLocatorInfo['name'][0].getValue()) if self._matchesRelation(signatureName, matchName, relationType): return True else: failureReason[0] = ("The custom signatureName \"" + signatureName.toUri() + "\" does not match matchName \"" + matchName.toUri() + "\" using relation " + relationType) return False # Is this a simple regex? simpleKeyRegex = keyLocatorInfo.getFirstValue("regex") if simpleKeyRegex != None: if NdnRegexTopMatcher(simpleKeyRegex).match(signatureName): return True else: failureReason[0] = ("The custom signatureName \"" + signatureName.toUri() + "\" does not regex match simpleKeyRegex \"" + simpleKeyRegex + "\"") return False # is this a hyper-relation? hyperRelationList = keyLocatorInfo["hyper-relation"] if len(hyperRelationList) >= 1: hyperRelation = hyperRelationList[0] keyRegex = hyperRelation.getFirstValue('k-regex') keyExpansion = hyperRelation.getFirstValue('k-expand') nameRegex = hyperRelation.getFirstValue('p-regex') nameExpansion = hyperRelation.getFirstValue('p-expand') relationType = hyperRelation.getFirstValue('h-relation') if (keyRegex != None and keyExpansion != None and nameRegex != None and nameExpansion != None and relationType != None): keyMatch = NdnRegexTopMatcher(keyRegex) if not keyMatch.match(signatureName): failureReason[0] = ( "The custom hyper-relation signatureName \"" + signatureName.toUri() + "\" does not match the keyRegex \"" + keyRegex + "\"") return False keyMatchPrefix = keyMatch.expand(keyExpansion) nameMatch = NdnRegexTopMatcher(nameRegex) if not nameMatch.match(objectName): failureReason[0] = ( "The custom hyper-relation objectName \"" + objectName.toUri() + "\" does not match the nameRegex \"" + nameRegex + "\"") return False nameMatchExpansion = nameMatch.expand(nameExpansion) if self._matchesRelation( nameMatchExpansion, keyMatchPrefix, relationType): return True else: failureReason[0] = ( "The custom hyper-relation nameMatch \"" + nameMatchExpansion.toUri() + "\" does not match the keyMatchPrefix \"" + keyMatchPrefix.toUri() + "\" using relation " + relationType) return False failureReason[0] = "Unrecognized checkerType: " + checkerType return False def _lookupCertificate(self, certID, isPath): """ This looks up certificates specified as base64-encoded data or file names. These are cached by filename or encoding to avoid repeated reading of files or decoding. :return: The certificate object, or None if not found. :rtype: IdentityCertificate """ if not self._isSecurityV1: raise SecurityException( "lookupCertificate: For security v2, use lookupCertificateV2()") try: certUri = self._fixedCertificateCache[certID] except KeyError: if isPath: # load the certificate data (base64 encoded IdentityCertificate) cert = TrustAnchorRefreshManager.loadIdentityCertificateFromFile( certID) else: certData = b64decode(certID) cert = IdentityCertificate() cert.wireDecode(Blob(certData, False)) certUri = cert.getName()[:-1].toUri() self._fixedCertificateCache[certID] = certUri self._certificateCache.insertCertificate(cert) else: cert = self._certificateCache.getCertificate(Name(certUri)) return cert def _lookupCertificateV2(self, certID, isPath): """ This looks up certificates specified as base64-encoded data or file names. These are cached by filename or encoding to avoid repeated reading of files or decoding. :return: The CertificateV2, or None if not found. :rtype: CertificateV2 """ if self._isSecurityV1: raise SecurityException( "lookupCertificateV2: For security v1, use lookupCertificate()") try: certUri = self._fixedCertificateCache[certID] except KeyError: if isPath: # load the certificate data (base64 encoded IdentityCertificate) cert = TrustAnchorRefreshManager.loadCertificateV2FromFile( certID) else: certData = b64decode(certID) cert = CertificateV2() cert.wireDecode(Blob(certData, False)) certUri = cert.getName()[:-1].toUri() self._fixedCertificateCache[certID] = certUri self._certificateCacheV2.insert(cert) else: cert = self._certificateCacheV2.find(Name(certUri)) return cert def _findMatchingRule(self, objName, matchType): """ Search the configuration file for the first rule that matches the data or signed interest name. In the case of interests, the name to match should exclude the timestamp, nonce, and signature components. :param Name objName: The name to be matched. :param string matchType: The rule type to match, "data" or "interest". """ rules = self.config["validator/rule"] for r in rules: if r['for'][0].getValue() == matchType: passed = True try: filters = r['filter'] except KeyError: # no filters means we pass! return r else: for f in filters: # don't check the type - it can only be name for now # we need to see if this is a regex or a relation regexPattern = f.getFirstValue("regex") if regexPattern == None: matchRelation =f.getFirstValue("relation") matchUri = f.getFirstValue("name") matchName = Name(matchUri) passed = self._matchesRelation(objName, matchName, matchRelation) else: passed = NdnRegexTopMatcher(regexPattern).match(objName) if not passed: break if passed: return r return None @staticmethod def _matchesRelation(name, matchName, matchRelation): """ Determines if a name satisfies the relation to another name, which can be one of: 'is-prefix-of' - passes if the name is equal to or has the other name as a prefix 'is-strict-prefix-of' - passes if the name has the other name as a prefix, and is not equal 'equal' - passes if the two names are equal """ passed = False if matchRelation == 'is-strict-prefix-of': if matchName.size() == name.size(): passed = False elif matchName.match(name): passed = True elif matchRelation == 'is-prefix-of': if matchName.match(name): passed = True elif matchRelation == 'equal': if matchName.equals(name): passed = True return passed @staticmethod def _extractSignature(dataOrInterest, wireFormat=None): """ Extract the signature information from the interest name or from the data packet. :param dataOrInterest: The object whose signature is needed. :type dataOrInterest: Data or Interest :param WireFormat wireFormat: (optional) The wire format used to decode signature information from the interest name. """ if isinstance(dataOrInterest, Data): return dataOrInterest.getSignature() elif isinstance(dataOrInterest, Interest): if wireFormat is None: # Don't use a default argument since getDefaultWireFormat can change. wireFormat = WireFormat.getDefaultWireFormat() try: signature = wireFormat.decodeSignatureInfoAndValue( dataOrInterest.getName().get(-2).getValue().buf(), dataOrInterest.getName().get(-1).getValue().buf(), False) except (IndexError, ValueError): return None return signature return None def _interestTimestampIsFresh(self, keyName, timestamp, failureReason): """ Determine whether the timestamp from the interest is newer than the last use of this key, or within the grace interval on first use. :param Name keyName: The name of the public key used to sign the interest. :paramt int timestamp: The timestamp extracted from the interest name. :param Array<str> failureReason: If verification fails, set failureReason[0] to the failure reason string. """ try: lastTimestamp = self._keyTimestamps[keyName.toUri()] except KeyError: now = Common.getNowMilliseconds() notBefore = now - self._keyGraceInterval notAfter = now + self._keyGraceInterval if not (timestamp > notBefore and timestamp < notAfter): return False failureReason[0] = ( "The command interest timestamp is not within the first use grace period of " + str(self._keyGraceInterval) + " milliseconds.") else: return True else: if timestamp <= lastTimestamp: failureReason[0] = ( "The command interest timestamp is not newer than the previous timestamp") return False else: return True def _updateTimestampForKey(self, keyName, timestamp): """ Trim the table size down if necessary, and insert/update the latest interest signing timestamp for the key. Any key which has not been used within the TTL period is purged. If the table is still too large, the oldest key is purged. :param Name keyName: The name of the public key used to sign the interest. :paramt int timestamp: The timestamp extracted from the interest name. """ self._keyTimestamps[keyName.toUri()] = timestamp if len(self._keyTimestamps) >= self._maxTrackedKeys: now = Common.getNowMilliseconds() oldestTimestamp = now oldestKey = None trackedKeys = self._keyTimestamps.keys() for keyUri in trackedKeys: ts = self._keyTimestamps[keyUri] if now - ts > self._keyTimestampTtl: del self._keyTimestamps[keyUri] elif ts < oldestTimestamp: oldestTimestamp = ts oldestKey = keyUri if len(self._keyTimestamps) > self._maxTrackedKeys: # have not removed enough del self._keyTimestamps[oldestKey] def checkVerificationPolicy(self, dataOrInterest, stepCount, onVerified, onValidationFailed, wireFormat = None): """ If there is a rule matching the data or interest, and the matching certificate is missing, download it. If there is no matching rule, verification fails. Otherwise, verify the signature using the public key in the IdentityStorage. :param dataOrInterest: The Data object or interest with the signature to check. :type dataOrInterest: Data or Interest :param int stepCount: The number of verification steps that have been done, used to track the verification progress. :param onVerified: If the signature is verified, this calls onVerified(dataOrInterest). NOTE: The library will log any exceptions raised by this callback, but for better error handling the callback should catch and properly handle any exceptions. :type onVerified: function object :param onValidationFailed: If the signature check fails, this calls onValidationFailed(dataOrInterest, reason). NOTE: The library will log any exceptions raised by this callback, but for better error handling the callback should catch and properly handle any exceptions. :type onValidationFailed: function object :return: None for no further step for looking up a certificate chain. :rtype: ValidationRequest """ objectName = dataOrInterest.getName() matchType = "data" # For command interests, we need to ignore the last 4 components when # matching the name. if isinstance(dataOrInterest, Interest): objectName = objectName.getPrefix(-4) matchType = "interest" signature = self._extractSignature(dataOrInterest, wireFormat) # no signature -> fail if signature is None: try: onValidationFailed( dataOrInterest, "Cannot extract the signature from " + dataOrInterest.getName().toUri()) except: logging.exception("Error in onValidationFailed") return None failureReason = ["unknown"] certificateInterest = self._getCertificateInterest( stepCount, matchType, objectName, signature, failureReason) if certificateInterest is None: try: onValidationFailed(dataOrInterest, failureReason[0]) except: logging.exception("Error in onValidationFailed") return None if certificateInterest.getName().size() > 0: def onCertificateDownloadComplete(data): if self._isSecurityV1: try: certificate = IdentityCertificate(data) except: try: onValidationFailed( dataOrInterest, "Cannot decode certificate " + data.getName().toUri()) except: logging.exception("Error in onValidationFailed") return None self._certificateCache.insertCertificate(certificate) else: try: certificate = CertificateV2(data) except: try: onValidationFailed( dataOrInterest, "Cannot decode certificate " + data.getName().toUri()) except: logging.exception("Error in onValidationFailed") return None self._certificateCacheV2.insert(certificate) self.checkVerificationPolicy(dataOrInterest, stepCount+1, onVerified, onValidationFailed) return ValidationRequest(certificateInterest, onCertificateDownloadComplete, onValidationFailed, 2, stepCount+1) # For interests, we must check that the timestamp is fresh enough. # This is done after (possibly) downloading the certificate to avoid # filling the cache with bad keys. if isinstance(dataOrInterest, Interest): signatureName = KeyLocator.getFromSignature(signature).getKeyName() if self._isSecurityV1: keyName = IdentityCertificate.certificateNameToPublicKeyName( signatureName) else: keyName = signatureName timestamp = dataOrInterest.getName().get(-4).toNumber() if not self._interestTimestampIsFresh( keyName, timestamp, failureReason): try: onValidationFailed(dataOrInterest, failureReason[0]) except: logging.exception("Error in onValidationFailed") return None # Certificate is known. Verify the signature. # wireEncode returns the cached encoding if available. if self._verify(signature, dataOrInterest.wireEncode(), failureReason): try: onVerified(dataOrInterest) except: logging.exception("Error in onVerified") if isinstance(dataOrInterest, Interest): self._updateTimestampForKey(keyName, timestamp) else: try: onValidationFailed(dataOrInterest, failureReason[0]) except: logging.exception("Error in onValidationFailed") def _getCertificateInterest(self, stepCount, matchType, objectName, signature, failureReason): """ This is a helper for checkVerificationPolicy to verify the rule and return a certificate interest to fetch the next certificate in the hierarchy if needed. :param int stepCount: The number of verification steps that have been done, used to track the verification progress. :param str matchType: Either "data" or "interest". :param Name objectName: The name of the data or interest packet. :param Signature signature: The Signature object for the data or interest packet. :param Array<str> failureReason: If can't determine the interest, set failureReason[0] to the failure reason. :return: None if can't determine the interest, otherwise the interest for the ValidationRequest to fetch the next certificate. However, if the interest has an empty name, the validation succeeded and no need to fetch a certificate. :rtype: Interest """ if stepCount > self._maxDepth: failureReason[0] = ("The verification stepCount " + stepCount + " exceeded the maxDepth " + self._maxDepth) return None # First see if we can find a rule to match this packet. try: matchedRule = self._findMatchingRule(objectName, matchType) except: matchedRule = None # No matching rule -> fail. if matchedRule is None: failureReason[0] = "No matching rule found for " + objectName.toUri() return None if not KeyLocator.canGetFromSignature(signature): # We only support signature types with key locators. failureReason[0] = "The signature type does not support a KeyLocator" return None keyLocator = KeyLocator.getFromSignature(signature) signatureName = keyLocator.getKeyName() # No key name in KeyLocator -> fail. if signatureName.size() == 0: failureReason[0] = "The signature KeyLocator doesn't have a key name" return None signatureMatches = self._checkSignatureMatch( signatureName, objectName, matchedRule, failureReason) if not signatureMatches: return None # Before we look up keys, refresh any certificate directories. self._refreshManager.refreshAnchors() # If we don't actually have the certificate yet, return a # certificateInterest for it. if self._isSecurityV1: foundCert = self._refreshManager.getCertificate(signatureName) if foundCert is None: foundCert = self._certificateCache.getCertificate(signatureName) if foundCert is None: return Interest(signatureName) else: foundCert = self._refreshManager.getCertificateV2(signatureName) if foundCert is None: foundCert = self._certificateCacheV2.find(signatureName) if foundCert is None: return Interest(signatureName) return Interest() def _verify(self, signatureInfo, signedBlob, failureReason): """ Check the type of signatureInfo to get the KeyLocator. Look in the IdentityStorage for the public key with the name in the KeyLocator and use it to verify the signedBlob. If the public key can't be found, return false. (This is a generalized method which can verify both a Data packet and an interest.) :param Signature signatureInfo: An object of a subclass of Signature, e.g. Sha256WithRsaSignature. :param SignedBlob signedBlob: the SignedBlob with the signed portion to verify. :param Array<str> failureReason: If verification fails, set failureReason[0] to the failure reason string. :return: True if the signature verifies, False if not. :rtype: boolean """ # We have already checked once that there is a key locator. keyLocator = KeyLocator.getFromSignature(signatureInfo) if (keyLocator.getType() == KeyLocatorType.KEYNAME): # Assume the key name is a certificate name. signatureName = keyLocator.getKeyName() if self._isSecurityV1: certificate = self._refreshManager.getCertificate(signatureName) if certificate is None: certificate = self._certificateCache.getCertificate( signatureName) if certificate is None: failureReason[0] = ("Cannot find a certificate with name " + signatureName.toUri()) return False publicKeyDer = certificate.getPublicKeyInfo().getKeyDer() if publicKeyDer.isNull(): # We don't expect this to happen. failureReason[0] = ( "There is no public key in the certificate with name " + certificate.getName().toUri()) return False else: certificate = self._refreshManager.getCertificateV2(signatureName) if certificate is None: certificate = self._certificateCacheV2.find( signatureName) if certificate is None: failureReason[0] = ("Cannot find a certificate with name " + signatureName.toUri()) return False try: publicKeyDer = certificate.getPublicKey() except: # We don't expect this to happen. failureReason[0] = ( "There is no public key in the certificate with name " + certificate.getName().toUri()) return False if self.verifySignature(signatureInfo, signedBlob, publicKeyDer): return True else: failureReason[0] = ( "The signature did not verify with the given public key") return False else: failureReason[0] = "The KeyLocator does not have a key name" return False