Python six.indexbytes() Examples

def enable(self, cpuSet, events):
    """
    Enables pmu events in a set of target cpus

    :param cpuSet: A set of cpu cores to enable pmu
    :param events: A list of pmu events to be enabled

    """
    if not self.device:
      raise Exception('xpedite device not enabled - use "with PMUCtrl() as pmuCtrl:" to init device')

    eventSet = self.buildEventSet(self.eventsDb, cpuSet, events)
    for cpu in cpuSet:
      requestGroup = self.buildRequestGroup(cpu, eventSet)
      LOGGER.debug(
        'sending request (%d bytes) to xpedite ko [%s]',
        len(requestGroup), ':'.join('{:02x}'.format(six.indexbytes(requestGroup, i))
                                    for i in range(0, len(requestGroup)))
      )
      self.device.write(requestGroup)
      self.device.flush()
    return eventSet 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def parse_response_data(resp_data):
    """
    According to https://fidoalliance.org/specs/fido-u2f-v1.0-nfc-bt-amendment-20150514/fido-u2f-raw-message-formats.html#authentication-response-message-success
    the response is made up of
    0:      user presence byte
    1-4:    counter
    5-:     signature

    :param resp_data: response data from the FIDO U2F client
    :type resp_data: hex string
    :return: tuple of user_presence_byte(byte), counter(int),
        signature(hexstring)
    """
    resp_data_bin = binascii.unhexlify(resp_data)
    user_presence = six.int2byte(six.indexbytes(resp_data_bin, 0))
    signature = resp_data_bin[5:]
    counter = struct.unpack(">L", resp_data_bin[1:5])[0]
    return user_presence, counter, signature 

def ReadTag(buffer, pos):
  """Read a tag from the buffer, and return a (tag_bytes, new_pos) tuple.

  We return the raw bytes of the tag rather than decoding them.  The raw
  bytes can then be used to look up the proper decoder.  This effectively allows
  us to trade some work that would be done in pure-python (decoding a varint)
  for work that is done in C (searching for a byte string in a hash table).
  In a low-level language it would be much cheaper to decode the varint and
  use that, but not in Python.
  """

  start = pos
  while six.indexbytes(buffer, pos) & 0x80:
    pos += 1
  pos += 1
  return (buffer[start:pos], pos)


# -------------------------------------------------------------------- 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def serialize(self):
        # fixup
        byte_length = (self.length + 7) // 8
        bin_addr = self._to_bin(self.addr)
        if (self.length % 8) == 0:
            bin_addr = bin_addr[:byte_length]
        else:
            # clear trailing bits in the last octet.
            # rfc doesn't require this.
            mask = 0xff00 >> (self.length % 8)
            last_byte = six.int2byte(
                six.indexbytes(bin_addr, byte_length - 1) & mask)
            bin_addr = bin_addr[:byte_length - 1] + last_byte
        self.addr = self._from_bin(bin_addr)

        buf = bytearray()
        msg_pack_into(self._PACK_STR, buf, 0, self.length)
        return buf + bytes(bin_addr) 

def ReadTag(buffer, pos):
  """Read a tag from the buffer, and return a (tag_bytes, new_pos) tuple.

  We return the raw bytes of the tag rather than decoding them.  The raw
  bytes can then be used to look up the proper decoder.  This effectively allows
  us to trade some work that would be done in pure-python (decoding a varint)
  for work that is done in C (searching for a byte string in a hash table).
  In a low-level language it would be much cheaper to decode the varint and
  use that, but not in Python.
  """

  start = pos
  while six.indexbytes(buffer, pos) & 0x80:
    pos += 1
  pos += 1
  return (six.binary_type(buffer[start:pos]), pos)


# -------------------------------------------------------------------- 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def ReadTag(buffer, pos):
  """Read a tag from the buffer, and return a (tag_bytes, new_pos) tuple.

  We return the raw bytes of the tag rather than decoding them.  The raw
  bytes can then be used to look up the proper decoder.  This effectively allows
  us to trade some work that would be done in pure-python (decoding a varint)
  for work that is done in C (searching for a byte string in a hash table).
  In a low-level language it would be much cheaper to decode the varint and
  use that, but not in Python.
  """

  start = pos
  while six.indexbytes(buffer, pos) & 0x80:
    pos += 1
  pos += 1
  return (buffer[start:pos], pos)


# -------------------------------------------------------------------- 

def ReadTag(buffer, pos):
  """Read a tag from the buffer, and return a (tag_bytes, new_pos) tuple.

  We return the raw bytes of the tag rather than decoding them.  The raw
  bytes can then be used to look up the proper decoder.  This effectively allows
  us to trade some work that would be done in pure-python (decoding a varint)
  for work that is done in C (searching for a byte string in a hash table).
  In a low-level language it would be much cheaper to decode the varint and
  use that, but not in Python.
  """

  start = pos
  while six.indexbytes(buffer, pos) & 0x80:
    pos += 1
  pos += 1
  return (buffer[start:pos], pos)


# -------------------------------------------------------------------- 

def _load_ssh_ecdsa_public_key(expected_key_type, decoded_data, backend):
    curve_name, rest = _ssh_read_next_string(decoded_data)
    data, rest = _ssh_read_next_string(rest)

    if expected_key_type != b"ecdsa-sha2-" + curve_name:
        raise ValueError(
            'Key header and key body contain different key type values.'
        )

    if rest:
        raise ValueError('Key body contains extra bytes.')

    curve = {
        b"nistp256": ec.SECP256R1,
        b"nistp384": ec.SECP384R1,
        b"nistp521": ec.SECP521R1,
    }[curve_name]()

    if six.indexbytes(data, 0) != 4:
        raise NotImplementedError(
            "Compressed elliptic curve points are not supported"
        )

    numbers = ec.EllipticCurvePublicNumbers.from_encoded_point(curve, data)
    return numbers.public_key(backend) 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def _load_ssh_ecdsa_public_key(expected_key_type, decoded_data, backend):
    curve_name, rest = _ssh_read_next_string(decoded_data)
    data, rest = _ssh_read_next_string(rest)

    if expected_key_type != b"ecdsa-sha2-" + curve_name:
        raise ValueError(
            'Key header and key body contain different key type values.'
        )

    if rest:
        raise ValueError('Key body contains extra bytes.')

    curve = {
        b"nistp256": ec.SECP256R1,
        b"nistp384": ec.SECP384R1,
        b"nistp521": ec.SECP521R1,
    }[curve_name]()

    if six.indexbytes(data, 0) != 4:
        raise NotImplementedError(
            "Compressed elliptic curve points are not supported"
        )

    return ec.EllipticCurvePublicKey.from_encoded_point(curve, data) 

def ReadTag(buffer, pos):
  """Read a tag from the buffer, and return a (tag_bytes, new_pos) tuple.

  We return the raw bytes of the tag rather than decoding them.  The raw
  bytes can then be used to look up the proper decoder.  This effectively allows
  us to trade some work that would be done in pure-python (decoding a varint)
  for work that is done in C (searching for a byte string in a hash table).
  In a low-level language it would be much cheaper to decode the varint and
  use that, but not in Python.
  """

  start = pos
  while six.indexbytes(buffer, pos) & 0x80:
    pos += 1
  pos += 1
  return (buffer[start:pos], pos)


# -------------------------------------------------------------------- 

def _load_ssh_ecdsa_public_key(expected_key_type, decoded_data, backend):
    curve_name, rest = _ssh_read_next_string(decoded_data)
    data, rest = _ssh_read_next_string(rest)

    if expected_key_type != b"ecdsa-sha2-" + curve_name:
        raise ValueError(
            'Key header and key body contain different key type values.'
        )

    if rest:
        raise ValueError('Key body contains extra bytes.')

    curve = {
        b"nistp256": ec.SECP256R1,
        b"nistp384": ec.SECP384R1,
        b"nistp521": ec.SECP521R1,
    }[curve_name]()

    if six.indexbytes(data, 0) != 4:
        raise NotImplementedError(
            "Compressed elliptic curve points are not supported"
        )

    return ec.EllipticCurvePublicKey.from_encoded_point(curve, data) 

def _load_ssh_ecdsa_public_key(expected_key_type, decoded_data, backend):
    curve_name, rest = _ssh_read_next_string(decoded_data)
    data, rest = _ssh_read_next_string(rest)

    if expected_key_type != b"ecdsa-sha2-" + curve_name:
        raise ValueError(
            'Key header and key body contain different key type values.'
        )

    if rest:
        raise ValueError('Key body contains extra bytes.')

    curve = {
        b"nistp256": ec.SECP256R1,
        b"nistp384": ec.SECP384R1,
        b"nistp521": ec.SECP521R1,
    }[curve_name]()

    if six.indexbytes(data, 0) != 4:
        raise NotImplementedError(
            "Compressed elliptic curve points are not supported"
        )

    return ec.EllipticCurvePublicKey.from_encoded_point(curve, data) 

def read_byte(self):
        if self.__size < 1:
            raise IndexError('Buffer queue is empty')
        segments = self.__segments
        segment = segments[0]
        segment_len = len(segment)
        offset = self.__offset
        if BufferQueue.is_eof(segment):
            octet = _EOF
        else:
            octet = self.__ord(six.indexbytes(segment, offset))
        offset += 1
        if offset == segment_len:
            offset = 0
            segments.popleft()
        self.__offset = offset
        self.__size -= 1
        self.position += 1
        return octet 

def _load_ssh_ecdsa_public_key(expected_key_type, decoded_data, backend):
    curve_name, rest = _ssh_read_next_string(decoded_data)
    data, rest = _ssh_read_next_string(rest)

    if expected_key_type != b"ecdsa-sha2-" + curve_name:
        raise ValueError(
            'Key header and key body contain different key type values.'
        )

    if rest:
        raise ValueError('Key body contains extra bytes.')

    curve = {
        b"nistp256": ec.SECP256R1,
        b"nistp384": ec.SECP384R1,
        b"nistp521": ec.SECP521R1,
    }[curve_name]()

    if six.indexbytes(data, 0) != 4:
        raise NotImplementedError(
            "Compressed elliptic curve points are not supported"
        )

    numbers = ec.EllipticCurvePublicNumbers.from_encoded_point(curve, data)
    return numbers.public_key(backend) 

def _get_unverified_token_data(token):
        if not isinstance(token, bytes):
            raise TypeError("token must be bytes.")

        try:
            data = base64.urlsafe_b64decode(token)
        except (TypeError, binascii.Error):
            raise InvalidToken

        if not data or six.indexbytes(data, 0) != 0x80:
            raise InvalidToken

        try:
            timestamp, = struct.unpack(">Q", data[1:9])
        except struct.error:
            raise InvalidToken
        return timestamp, data 

def _int_factory(sign, data):
    def parse_int():
        value = 0
        length = len(data)
        while length >= 8:
            segment = _rslice(data, length, 8)
            value <<= 64
            value |= unpack('>Q', segment)[0]
            length -= 8
        if length >= 4:
            segment = _rslice(data, length, 4)
            value <<= 32
            value |= unpack('>I', segment)[0]
            length -= 4
        if length >= 2:
            segment = _rslice(data, length, 2)
            value <<= 16
            value |= unpack('>H', segment)[0]
            length -= 2
        if length == 1:
            value <<= 8
            value |= six.indexbytes(data, -length)
        return sign * value
    return parse_int 

def _VarintDecoder(mask, result_type):
  """Return an encoder for a basic varint value (does not include tag).

  Decoded values will be bitwise-anded with the given mask before being
  returned, e.g. to limit them to 32 bits.  The returned decoder does not
  take the usual "end" parameter -- the caller is expected to do bounds checking
  after the fact (often the caller can defer such checking until later).  The
  decoder returns a (value, new_pos) pair.
  """

  def DecodeVarint(buffer, pos):
    result = 0
    shift = 0
    while 1:
      b = six.indexbytes(buffer, pos)
      result |= ((b & 0x7f) << shift)
      pos += 1
      if not (b & 0x80):
        result &= mask
        result = result_type(result)
        return (result, pos)
      shift += 7
      if shift >= 64:
        raise _DecodeError('Too many bytes when decoding varint.')
  return DecodeVarint 

def parser(cls, buf):
        (diag, flags, detect_mult, length, my_discr, your_discr,
         desired_min_tx_interval, required_min_rx_interval,
         required_min_echo_rx_interval) = \
            struct.unpack_from(cls._PACK_STR, buf[:cls._PACK_STR_LEN])

        ver = diag >> 5
        diag = diag & 0x1f
        state = flags >> 6
        flags = flags & 0x3f

        if flags & BFD_FLAG_AUTH_PRESENT:
            auth_type = six.indexbytes(buf, cls._PACK_STR_LEN)
            auth_cls = cls._auth_parsers[auth_type].\
                parser(buf[cls._PACK_STR_LEN:])[0]
        else:
            auth_cls = None

        msg = cls(ver, diag, state, flags, detect_mult,
                  my_discr, your_discr, desired_min_tx_interval,
                  required_min_rx_interval, required_min_echo_rx_interval,
                  auth_cls)

        return msg, None, None 

def read_byte(self):
        if len(self.data) < 1:
            raise ValueError("Invalid DER input: insufficient data")
        ret = six.indexbytes(self.data, 0)
        self.data = self.data[1:]
        return ret 

def _get_unverified_token_data(token):
        utils._check_bytes("token", token)
        try:
            data = base64.urlsafe_b64decode(token)
        except (TypeError, binascii.Error):
            raise InvalidToken

        if not data or six.indexbytes(data, 0) != 0x80:
            raise InvalidToken

        try:
            timestamp, = struct.unpack(">Q", data[1:9])
        except struct.error:
            raise InvalidToken
        return timestamp, data 

def read_optional_element(self, expected_tag):
        if len(self.data) > 0 and six.indexbytes(self.data, 0) == expected_tag:
            return self.read_element(expected_tag)
        return None 

def buildPerfEventsRequest(eventsDb, events):
    """
    Builds a request to enable events with perf events api

    :param eventsDb: Handle to database of PMU events for the target cpu
    :param events: A list of pmu events to be enabled

    """
    eventSet = PMUCtrl.buildEventSet(eventsDb, [], events)
    if not eventSet.offcoreRequestCount():
      requestGroup = PMUCtrl.buildRequestGroup(0, eventSet)
      pdu = ':'.join('{:02x}'.format(six.indexbytes(requestGroup, i)) for i in range(0, len(requestGroup)))
      return (eventSet, pdu)
    return (None, None)