Python TlvEncoder.writeNonNegativeInteger方法代码示例

# 需要导入模块: from pyndn.encoding.tlv.tlv_encoder import TlvEncoder [as 别名]
# 或者: from pyndn.encoding.tlv.tlv_encoder.TlvEncoder import writeNonNegativeInteger [as 别名]
    def generate(self, interest, keyChain, certificateName, wireFormat = None):
        """
        Append a timestamp component and a random value component to interest's
        name. This ensures that the timestamp is greater than the timestamp used 
        in the previous call. Then use keyChain to sign the interest which 
        appends a SignatureInfo component and a component with the signature 
        bits. If the interest lifetime is not set, this sets it.

        :param Interest interest: The interest whose name is append with 
          components.
        :param KeyChain keyChain: The KeyChain for calling sign.
        :param Name certificateName: The certificate name of the key to use for 
          signing.
        :param wireFormat: (optional) A WireFormat object used to encode the 
          SignatureInfo and to encode interest name for signing. If omitted, use
          WireFormat.getDefaultWireFormat().
        :type wireFormat: A subclass of WireFormat
        """
        if wireFormat == None:
            # Don't use a default argument since getDefaultWireFormat can change.
            wireFormat = WireFormat.getDefaultWireFormat()

        timestamp =  round(Common.getNowMilliseconds())
        while timestamp <= self._lastTimestamp:
          timestamp += 1.0

        # The timestamp is encoded as a TLV nonNegativeInteger.
        encoder = TlvEncoder(8)
        encoder.writeNonNegativeInteger(int(timestamp))
        interest.getName().append(Blob(encoder.getOutput(), False))
        
        # The random value is a TLV nonNegativeInteger too, but we know it is 8 
        # bytes, so we don't need to call the nonNegativeInteger encoder.        
        randomBuffer = bytearray(8)
        for i in range(len(randomBuffer)):
            randomBuffer[i] = _systemRandom.randint(0, 0xff)                
        interest.getName().append(Blob(randomBuffer, False))

        keyChain.sign(interest, certificateName, wireFormat)

        if (interest.getInterestLifetimeMilliseconds() == None or
            interest.getInterestLifetimeMilliseconds()< 0):
          # The caller has not set the interest lifetime, so set it here.
          interest.setInterestLifetimeMilliseconds(1000.0)

        # We successfully signed the interest, so update the timestamp.
        self._lastTimestamp = timestamp
        

# 需要导入模块: from pyndn.encoding.tlv.tlv_encoder import TlvEncoder [as 别名]
# 或者: from pyndn.encoding.tlv.tlv_encoder.TlvEncoder import writeNonNegativeInteger [as 别名]
    def prepareCommandInterestName(self, interest, wireFormat = None):
        """
        Append a timestamp component and a random nonce component to interest's
        name. This ensures that the timestamp is greater than the timestamp used
        in the previous call.

        :param Interest interest: The interest whose name is append with
          components.
        :param WireFormat wireFormat: (optional) A WireFormat object used to
          encode the SignatureInfo. If omitted, use WireFormat
          getDefaultWireFormat().
        """
        if wireFormat == None:
            wireFormat = WireFormat.getDefaultWireFormat()

        # _nowOffsetMilliseconds is only used for testing.
        now = Common.getNowMilliseconds() + self._nowOffsetMilliseconds
        timestamp =  round(now)
        while timestamp <= self._lastUsedTimestamp:
          timestamp += 1.0

        # Update the timestamp now. In the small chance that signing fails, it
        # just means that we have bumped the timestamp.
        self._lastUsedTimestamp = timestamp

        # The timestamp is encoded as a TLV nonNegativeInteger.
        encoder = TlvEncoder(8)
        encoder.writeNonNegativeInteger(int(timestamp))
        interest.getName().append(Blob(encoder.getOutput(), False))

        # The random value is a TLV nonNegativeInteger too, but we know it is 8
        # bytes, so we don't need to call the nonNegativeInteger encoder.
        randomBuffer = bytearray(8)
        for i in range(len(randomBuffer)):
            randomBuffer[i] = _systemRandom.randint(0, 0xff)
        interest.getName().append(Blob(randomBuffer, False))