def encodeForwardingEntry(self, forwardingEntry):
"""
Encode forwardingEntry and return the encoding.
:param forwardingEntry: The ForwardingEntry object to encode.
:type forwardingEntry: ForwardingEntry
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeOptionalNonNegativeIntegerTlvFromFloat(
Tlv.FreshnessPeriod, forwardingEntry.getFreshnessPeriod())
encoder.writeNonNegativeIntegerTlv(
Tlv.ForwardingFlags,
forwardingEntry.getForwardingFlags().getForwardingEntryFlags())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.FaceID, forwardingEntry.getFaceId())
self._encodeName(forwardingEntry.getPrefix(), encoder)
if (forwardingEntry.getAction() != None and
len(forwardingEntry.getAction()) > 0):
# Convert str to a bytearray.
encoder.writeBlobTlv(
Tlv.Action, bytearray(forwardingEntry.getAction(), 'ascii'))
encoder.writeTypeAndLength(Tlv.ForwardingEntry,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeDelegationSet(self, delegationSet):
"""
Encode the DelegationSet in NDN-TLV and return the encoding. Note that
the sequence of Delegation does not have an outer TLV type and length
because it is intended to use the type and length of a Data packet's
Content.
:param DelegationSet delegationSet: The DelegationSet object to
encode.
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
# Encode backwards.
for i in range(delegationSet.size() - 1, -1, -1):
saveLength = len(encoder)
Tlv0_1_1WireFormat._encodeName(delegationSet.get(i).getName(), encoder)
encoder.writeNonNegativeIntegerTlv(
Tlv.Link_Preference, delegationSet.get(i).getPreference())
encoder.writeTypeAndLength(
Tlv.Link_Delegation, len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeEncryptedContent(self, encryptedContent):
"""
Encode the EncryptedContent in NDN-TLV and return the encoding.
:param EncryptedContent encryptedContent: The EncryptedContent object to
encode.
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeBlobTlv(
Tlv.Encrypt_EncryptedPayload, encryptedContent.getPayload().buf())
encoder.writeOptionalBlobTlv(
Tlv.Encrypt_InitialVector, encryptedContent.getInitialVector().buf())
# Assume the algorithmType value is the same as the TLV type.
encoder.writeNonNegativeIntegerTlv(
Tlv.Encrypt_EncryptionAlgorithm, encryptedContent.getAlgorithmType())
Tlv0_1_1WireFormat._encodeKeyLocator(
Tlv.KeyLocator, encryptedContent.getKeyLocator(), encoder)
encoder.writeTypeAndLength(
Tlv.Encrypt_EncryptedContent, len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeControlResponse(self, controlResponse):
"""
Encode controlResponse and return the encoding.
:param controlResponse: The ControlResponse object to encode.
:type controlResponse: ControlResponse
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
# Encode the body.
if controlResponse.getBodyAsControlParameters() != None:
self._encodeControlParameters(
controlResponse.getBodyAsControlParameters(), encoder)
encoder.writeBlobTlv(
Tlv.NfdCommand_StatusText, Blob(controlResponse.getStatusText()).buf())
encoder.writeNonNegativeIntegerTlv(
Tlv.NfdCommand_StatusCode, controlResponse.getStatusCode())
encoder.writeTypeAndLength(Tlv.NfdCommand_ControlResponse,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeData(self, data):
"""
Encode data in NDN-TLV and return the encoding and signed offsets.
:param Data data: The Data object to encode.
:return: A Tuple of (encoding, signedPortionBeginOffset,
signedPortionEndOffset) where encoding is a Blob containing the
encoding, signedPortionBeginOffset is the offset in the encoding of
the beginning of the signed portion, and signedPortionEndOffset is
the offset in the encoding of the end of the signed portion.
:rtype: (Blob, int, int)
"""
encoder = TlvEncoder(1500)
saveLength = len(encoder)
# Encode backwards.
encoder.writeBlobTlv(Tlv.SignatureValue,
data.getSignature().getSignature().buf())
signedPortionEndOffsetFromBack = len(encoder)
self._encodeSignatureInfo(data.getSignature(), encoder)
encoder.writeBlobTlv(Tlv.Content, data.getContent().buf())
self._encodeMetaInfo(data.getMetaInfo(), encoder)
self._encodeName(data.getName(), encoder)
signedPortionBeginOffsetFromBack = len(encoder)
encoder.writeTypeAndLength(Tlv.Data, len(encoder) - saveLength)
signedPortionBeginOffset = (len(encoder) -
signedPortionBeginOffsetFromBack)
signedPortionEndOffset = len(encoder) - signedPortionEndOffsetFromBack
return (Blob(encoder.getOutput(),
False), signedPortionBeginOffset, signedPortionEndOffset)
def encodeForwardingEntry(self, forwardingEntry):
"""
Encode forwardingEntry and return the encoding.
:param forwardingEntry: The ForwardingEntry object to encode.
:type forwardingEntry: ForwardingEntry
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeOptionalNonNegativeIntegerTlvFromFloat(
Tlv.FreshnessPeriod, forwardingEntry.getFreshnessPeriod())
encoder.writeNonNegativeIntegerTlv(
Tlv.ForwardingFlags,
forwardingEntry.getForwardingFlags().getForwardingEntryFlags())
encoder.writeOptionalNonNegativeIntegerTlv(Tlv.FaceID,
forwardingEntry.getFaceId())
self._encodeName(forwardingEntry.getPrefix(), encoder)
if (forwardingEntry.getAction() != None
and len(forwardingEntry.getAction()) > 0):
# Convert str to a bytearray.
encoder.writeBlobTlv(
Tlv.Action, bytearray(forwardingEntry.getAction(), 'ascii'))
encoder.writeTypeAndLength(Tlv.ForwardingEntry,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeData(self, data):
"""
Encode data in NDN-TLV and return the encoding and signed offsets.
:param Data data: The Data object to encode.
:return: A Tuple of (encoding, signedPortionBeginOffset,
signedPortionEndOffset) where encoding is a Blob containing the
encoding, signedPortionBeginOffset is the offset in the encoding of
the beginning of the signed portion, and signedPortionEndOffset is
the offset in the encoding of the end of the signed portion.
:rtype: (Blob, int, int)
"""
encoder = TlvEncoder(1500)
saveLength = len(encoder)
# Encode backwards.
# TODO: The library needs to handle other signature types than
# SignatureSha256WithRsa.
encoder.writeBlobTlv(Tlv.SignatureValue,
data.getSignature().getSignature().buf())
signedPortionEndOffsetFromBack = len(encoder)
self._encodeSignatureSha256WithRsa(data.getSignature(), encoder)
encoder.writeBlobTlv(Tlv.Content, data.getContent().buf())
self._encodeMetaInfo(data.getMetaInfo(), encoder)
self._encodeName(data.getName(), encoder)
signedPortionBeginOffsetFromBack = len(encoder)
encoder.writeTypeAndLength(Tlv.Data, len(encoder) - saveLength)
signedPortionBeginOffset = (len(encoder) -
signedPortionBeginOffsetFromBack)
signedPortionEndOffset = len(encoder) - signedPortionEndOffsetFromBack
return (Blob(encoder.getOutput(), False), signedPortionBeginOffset,
signedPortionEndOffset)
def encodeStateVector(stateVector, stateVectorKeys):
"""
Encode the stateVector as TLV.
:param dict<str,int> stateVector: The state vector dictionary where
the key is the member ID string and the value is the sequence number.
:param list<str> stateVectorKeys: The key strings of stateVector,
sorted in the order to be encoded.
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
for i in range(len(stateVectorKeys) - 1, -1, -1):
saveLengthForEntry = len(encoder)
encoder.writeNonNegativeIntegerTlv(
StateVectorSync2018.TLV_StateVector_SequenceNumber,
stateVector[stateVectorKeys[i]])
encoder.writeBlobTlv(StateVectorSync2018.TLV_StateVector_MemberId,
Blob(stateVectorKeys[i]).buf())
encoder.writeTypeAndLength(
StateVectorSync2018.TLV_StateVectorEntry,
len(encoder) - saveLengthForEntry)
encoder.writeTypeAndLength(StateVectorSync2018.TLV_StateVector,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def wireEncode(self):
encoder = TlvEncoder(500)
saveLength = len(encoder)
# if self.getValidityPeriod().hasPeriod():
# Tlv0_2WireFormat._encodeValidityPeriod(self.getValidityPeriod(), encoder)
Tlv0_2WireFormat._encodeKeyLocator(Tlv.KeyLocator, self.getKeyLocator(), encoder)
encoder.writeNonNegativeIntegerTlv(Tlv.SignatureType, Tlv.SignatureType_Sha256WithAbsSignature)
encoder.writeTypeAndLength(Tlv.SignatureInfo, len(encoder) - saveLength)
self.setSignatureInfoEncoding(Blob(encoder.getOutput(), False), Tlv.SignatureType_Sha256WithAbsSignature)
def encodeControlParameters(self, controlParameters):
"""
Encode controlParameters and return the encoding.
:param controlParameters: The ControlParameters object to encode.
:type controlParameters: ControlParameters
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeOptionalNonNegativeIntegerTlvFromFloat(
Tlv.ControlParameters_ExpirationPeriod,
controlParameters.getExpirationPeriod())
if controlParameters.getStrategy().size() > 0:
strategySaveLength = len(encoder)
self._encodeName(controlParameters.getStrategy(), encoder)
encoder.writeTypeAndLength(Tlv.ControlParameters_Strategy,
len(encoder) - strategySaveLength)
flags = controlParameters.getForwardingFlags().getNfdForwardingFlags()
if (flags != ForwardingFlags().getNfdForwardingFlags()):
# The flags are not the default value.
encoder.writeNonNegativeIntegerTlv(Tlv.ControlParameters_Flags,
flags)
encoder.writeOptionalNonNegativeIntegerTlv(Tlv.ControlParameters_Cost,
controlParameters.getCost())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.ControlParameters_Origin, controlParameters.getOrigin())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.ControlParameters_LocalControlFeature,
controlParameters.getLocalControlFeature())
if len(controlParameters.getUri()) != 0:
encoder.writeBlobTlv(Tlv.ControlParameters_Uri,
Blob(controlParameters.getUri()).buf())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.ControlParameters_FaceId, controlParameters.getFaceId())
if controlParameters.getName() != None:
self._encodeName(controlParameters.getName(), encoder)
encoder.writeTypeAndLength(Tlv.ControlParameters_ControlParameters,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeInterest(self, interest):
"""
Encode interest in NDN-TLV and return the encoding.
:param Interest interest: The Interest object to encode.
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeOptionalNonNegativeIntegerTlvFromFloat(
Tlv.InterestLifetime, interest.getInterestLifetimeMilliseconds())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.Scope, interest.getScope())
# Encode the Nonce as 4 bytes.
if interest.getNonce().size() == 0:
# This is the most common case. Generate a nonce.
nonce = bytearray(4)
for i in range(4):
nonce[i] = _systemRandom.randint(0, 0xff)
encoder.writeBlobTlv(Tlv.Nonce, nonce)
elif interest.getNonce().size() < 4:
nonce = bytearray(4)
# Copy existing nonce bytes.
nonce[:interest.getNonce().size()] = interest.getNonce().buf()
# Generate random bytes for remaining bytes in the nonce.
for i in range(interest.getNonce().size(), 4):
nonce[i] = _systemRandom.randint(0, 0xff)
encoder.writeBlobTlv(Tlv.Nonce, nonce)
elif interest.getNonce().size() == 4:
# Use the nonce as-is.
encoder.writeBlobTlv(Tlv.Nonce, interest.getNonce().buf())
else:
# Truncate.
encoder.writeBlobTlv(Tlv.Nonce, interest.getNonce().buf()[:4])
self._encodeSelectors(interest, encoder)
self._encodeName(interest.getName(), encoder)
encoder.writeTypeAndLength(Tlv.Interest, len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeControlParameters(self, controlParameters):
"""
Encode controlParameters and return the encoding.
:param controlParameters: The ControlParameters object to encode.
:type controlParameters: ControlParameters
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeOptionalNonNegativeIntegerTlvFromFloat(
Tlv.ControlParameters_ExpirationPeriod,
controlParameters.getExpirationPeriod())
# TODO: Encode Strategy.
flags = controlParameters.getForwardingFlags().getNfdForwardingFlags()
if (flags != ForwardingFlags().getNfdForwardingFlags()):
# The flags are not the default value.
encoder.writeNonNegativeIntegerTlv(
Tlv.ControlParameters_Flags, flags)
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.ControlParameters_Cost, controlParameters.getCost())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.ControlParameters_Origin, controlParameters.getOrigin())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.ControlParameters_LocalControlFeature,
controlParameters.getLocalControlFeature())
# TODO: Encode Uri.
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.ControlParameters_FaceId, controlParameters.getFaceId())
if controlParameters.getName().size() > 0:
self._encodeName(controlParameters.getName(), encoder)
encoder.writeTypeAndLength(Tlv.ControlParameters_ControlParameters,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def wireEncode(self):
"""
Encode this as an NDN-TLV PSyncContent.
:return: The encoding as a Blob.
:rtype: Blob
"""
# Encode directly as TLV. We don't support the WireFormat abstraction
# because this isn't meant to go directly on the wire.
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
for i in range(len(self._content) - 1, -1, -1):
Tlv0_3WireFormat._encodeName(self._content[i], encoder)
encoder.writeTypeAndLength(
PSyncState.Tlv_PSyncContent, len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def _encodeLpNack(interest, networkNack):
"""
Encode the interest into an NDN-TLV LpPacket as a NACK with the reason
code in the networkNack object.
TODO: Generalize this and move to WireFormat.encodeLpPacket.
:param Interest interest: The Interest to put in the LpPacket fragment.
:param NetworkNack networkNack: The NetworkNack with the reason code.
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
# Encode the fragment with the Interest.
encoder.writeBlobTlv(Tlv.LpPacket_Fragment,
interest.wireEncode(TlvWireFormat.get()).buf())
# Encode the reason.
if (networkNack.getReason() == NetworkNack.Reason.NONE
or networkNack.getReason() == NetworkNack.Reason.CONGESTION
or networkNack.getReason() == NetworkNack.Reason.DUPLICATE
or networkNack.getReason() == NetworkNack.Reason.NO_ROUTE):
# The Reason enum is set up with the correct integer for each NDN-TLV Reason.
reason = networkNack.getReason()
elif networkNack.getReason() == NetworkNack.Reason.OTHER_CODE:
reason = networkNack.getOtherReasonCode()
else:
# We don't expect this to happen.
raise RuntimeError("unrecognized NetworkNack.getReason() value")
nackSaveLength = len(encoder)
encoder.writeNonNegativeIntegerTlv(Tlv.LpPacket_NackReason, reason)
encoder.writeTypeAndLength(Tlv.LpPacket_Nack,
len(encoder) - nackSaveLength)
encoder.writeTypeAndLength(Tlv.LpPacket_LpPacket,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def _encodeLpNack(interest, networkNack):
"""
Encode the interest into an NDN-TLV LpPacket as a NACK with the reason
code in the networkNack object.
TODO: Generalize this and move to WireFormat.encodeLpPacket.
:param Interest interest: The Interest to put in the LpPacket fragment.
:param NetworkNack networkNack: The NetworkNack with the reason code.
:return: A Blob containing the encoding.
:rtype: Blob
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
# Encode the fragment with the Interest.
encoder.writeBlobTlv(
Tlv.LpPacket_Fragment, interest.wireEncode(TlvWireFormat.get()).buf())
# Encode the reason.
if (networkNack.getReason() == NetworkNack.Reason.NONE or
networkNack.getReason() == NetworkNack.Reason.CONGESTION or
networkNack.getReason() == NetworkNack.Reason.DUPLICATE or
networkNack.getReason() == NetworkNack.Reason.NO_ROUTE):
# The Reason enum is set up with the correct integer for each NDN-TLV Reason.
reason = networkNack.getReason()
elif networkNack.getReason() == NetworkNack.Reason.OTHER_CODE:
reason = networkNack.getOtherReasonCode()
else:
# We don't expect this to happen.
raise RuntimeError("unrecognized NetworkNack.getReason() value")
nackSaveLength = len(encoder)
encoder.writeNonNegativeIntegerTlv(Tlv.LpPacket_NackReason, reason)
encoder.writeTypeAndLength(
Tlv.LpPacket_Nack, len(encoder) - nackSaveLength)
encoder.writeTypeAndLength(
Tlv.LpPacket_LpPacket, len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def wireEncode(self):
"""
Encode this Schedule.
:return: The encoded buffer.
:rtype: Blob
"""
# For now, don't use WireFormat and hardcode to use TLV since the
# encoding doesn't go out over the wire, only into the local SQL database.
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
# Encode the blackIntervalList.
saveLengthForList = len(encoder)
for i in range(len(self._blackIntervalList) - 1, -1, -1):
Schedule._encodeRepetitiveInterval(self._blackIntervalList[i],
encoder)
encoder.writeTypeAndLength(Tlv.Encrypt_BlackIntervalList,
len(encoder) - saveLengthForList)
# Encode the whiteIntervalList.
saveLengthForList = len(encoder)
for i in range(len(self._whiteIntervalList) - 1, -1, -1):
Schedule._encodeRepetitiveInterval(self._whiteIntervalList[i],
encoder)
encoder.writeTypeAndLength(Tlv.Encrypt_WhiteIntervalList,
len(encoder) - saveLengthForList)
encoder.writeTypeAndLength(Tlv.Encrypt_Schedule,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def wireEncode(self):
"""
Encode this Schedule.
:return: The encoded buffer.
:rtype: Blob
"""
# For now, don't use WireFormat and hardcode to use TLV since the
# encoding doesn't go out over the wire, only into the local SQL database.
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
# Encode the blackIntervalList.
saveLengthForList = len(encoder)
for i in range(len(self._blackIntervalList) - 1, -1, -1):
Schedule._encodeRepetitiveInterval(self._blackIntervalList[i], encoder)
encoder.writeTypeAndLength(Tlv.Encrypt_BlackIntervalList, len(encoder) - saveLengthForList)
# Encode the whiteIntervalList.
saveLengthForList = len(encoder)
for i in range(len(self._whiteIntervalList) - 1, -1, -1):
Schedule._encodeRepetitiveInterval(self._whiteIntervalList[i], encoder)
encoder.writeTypeAndLength(Tlv.Encrypt_WhiteIntervalList, len(encoder) - saveLengthForList)
encoder.writeTypeAndLength(Tlv.Encrypt_Schedule, len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def wireEncode(self, wireFormat=None):
"""
Encode this as an NDN-TLV SafeBag.
:return: The encoded byte array as a Blob.
:rtype: Blob
"""
# Encode directly as TLV. We don't support the WireFormat abstraction
# because this isn't meant to go directly on the wire.
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeBlobTlv(Tlv.SafeBag_EncryptedKeyBag,
self._privateKeyBag.buf())
# Add the entire Data packet encoding as is.
encoder.writeBuffer(
self._certificate.wireEncode(TlvWireFormat.get()).buf())
encoder.writeTypeAndLength(Tlv.SafeBag_SafeBag,
len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def wireEncode(self, wireFormat = None):
"""
Encode this as an NDN-TLV SafeBag.
:return: The encoded byte array as a Blob.
:rtype: Blob
"""
# Encode directly as TLV. We don't support the WireFormat abstraction
# because this isn't meant to go directly on the wire.
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeBlobTlv(
Tlv.SafeBag_EncryptedKeyBag, self._privateKeyBag.buf())
# Add the entire Data packet encoding as is.
encoder.writeBuffer(
self._certificate.wireEncode(TlvWireFormat.get()).buf())
encoder.writeTypeAndLength(
Tlv.SafeBag_SafeBag, len(encoder) - saveLength)
return Blob(encoder.getOutput(), False)
def encodeInterest(self, interest):
"""
Encode interest in NDN-TLV and return the encoding.
:param Interest interest: The Interest object to encode.
:return: A Tuple of (encoding, signedPortionBeginOffset,
signedPortionEndOffset) where encoding is a Blob containing the
encoding, signedPortionBeginOffset is the offset in the encoding of
the beginning of the signed portion, and signedPortionEndOffset is
the offset in the encoding of the end of the signed portion. The
signed portion starts from the first name component and ends just
before the final name component (which is assumed to be a signature
for a signed interest).
:rtype: (Blob, int, int)
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeOptionalNonNegativeIntegerTlvFromFloat(
Tlv.InterestLifetime, interest.getInterestLifetimeMilliseconds())
encoder.writeOptionalNonNegativeIntegerTlv(Tlv.Scope,
interest.getScope())
# Encode the Nonce as 4 bytes.
if interest.getNonce().size() == 0:
# This is the most common case. Generate a nonce.
nonce = bytearray(4)
for i in range(4):
nonce[i] = _systemRandom.randint(0, 0xff)
encoder.writeBlobTlv(Tlv.Nonce, nonce)
elif interest.getNonce().size() < 4:
nonce = bytearray(4)
# Copy existing nonce bytes.
nonce[:interest.getNonce().size()] = interest.getNonce().buf()
# Generate random bytes for remaining bytes in the nonce.
for i in range(interest.getNonce().size(), 4):
nonce[i] = _systemRandom.randint(0, 0xff)
encoder.writeBlobTlv(Tlv.Nonce, nonce)
elif interest.getNonce().size() == 4:
# Use the nonce as-is.
encoder.writeBlobTlv(Tlv.Nonce, interest.getNonce().buf())
else:
# Truncate.
encoder.writeBlobTlv(Tlv.Nonce, interest.getNonce().buf()[:4])
self._encodeSelectors(interest, encoder)
(tempSignedPortionBeginOffset, tempSignedPortionEndOffset) = \
self._encodeName(interest.getName(), encoder)
signedPortionBeginOffsetFromBack = (len(encoder) -
tempSignedPortionBeginOffset)
signedPortionEndOffsetFromBack = (len(encoder) -
tempSignedPortionEndOffset)
encoder.writeTypeAndLength(Tlv.Interest, len(encoder) - saveLength)
signedPortionBeginOffset = (len(encoder) -
signedPortionBeginOffsetFromBack)
signedPortionEndOffset = len(encoder) - signedPortionEndOffsetFromBack
return (Blob(encoder.getOutput(),
False), signedPortionBeginOffset, signedPortionEndOffset)
def encodeInterest(self, interest):
"""
Encode interest in NDN-TLV and return the encoding.
:param Interest interest: The Interest object to encode.
:return: A Tuple of (encoding, signedPortionBeginOffset,
signedPortionEndOffset) where encoding is a Blob containing the
encoding, signedPortionBeginOffset is the offset in the encoding of
the beginning of the signed portion, and signedPortionEndOffset is
the offset in the encoding of the end of the signed portion. The
signed portion starts from the first name component and ends just
before the final name component (which is assumed to be a signature
for a signed interest).
:rtype: (Blob, int, int)
"""
encoder = TlvEncoder(256)
saveLength = len(encoder)
# Encode backwards.
encoder.writeOptionalNonNegativeIntegerTlvFromFloat(
Tlv.InterestLifetime, interest.getInterestLifetimeMilliseconds())
encoder.writeOptionalNonNegativeIntegerTlv(
Tlv.Scope, interest.getScope())
# Encode the Nonce as 4 bytes.
if interest.getNonce().size() == 0:
# This is the most common case. Generate a nonce.
nonce = bytearray(4)
for i in range(4):
nonce[i] = _systemRandom.randint(0, 0xff)
encoder.writeBlobTlv(Tlv.Nonce, nonce)
elif interest.getNonce().size() < 4:
nonce = bytearray(4)
# Copy existing nonce bytes.
nonce[:interest.getNonce().size()] = interest.getNonce().buf()
# Generate random bytes for remaining bytes in the nonce.
for i in range(interest.getNonce().size(), 4):
nonce[i] = _systemRandom.randint(0, 0xff)
encoder.writeBlobTlv(Tlv.Nonce, nonce)
elif interest.getNonce().size() == 4:
# Use the nonce as-is.
encoder.writeBlobTlv(Tlv.Nonce, interest.getNonce().buf())
else:
# Truncate.
encoder.writeBlobTlv(Tlv.Nonce, interest.getNonce().buf()[:4])
self._encodeSelectors(interest, encoder)
(tempSignedPortionBeginOffset, tempSignedPortionEndOffset) = \
self._encodeName(interest.getName(), encoder)
signedPortionBeginOffsetFromBack = (len(encoder) -
tempSignedPortionBeginOffset)
signedPortionEndOffsetFromBack = (len(encoder) -
tempSignedPortionEndOffset)
encoder.writeTypeAndLength(Tlv.Interest, len(encoder) - saveLength)
signedPortionBeginOffset = (len(encoder) -
signedPortionBeginOffsetFromBack)
signedPortionEndOffset = len(encoder) - signedPortionEndOffsetFromBack
return (Blob(encoder.getOutput(), False), signedPortionBeginOffset,
signedPortionEndOffset)
