relay

class cell.relay.RelayCell(header, rheader=None, rpayload='')

Bases: oppy.cell.fixedlen.FixedLenCell

A container class for representing relay cells.

Note

All Relay cells are fixed-length (length determined by Link Protocol version in use).

rheader = None

rpayload = None

getBytes(trimmed=False)

Construct and return the byte string represented by this cell.

Parameters:trimmed (bool) – If True, return the non-padded payload. Otherwise pad the payload with null bytes to the fixed-size length in use according to the Link Protocol version. Returns:str byte string represented by this cell

relayHeaderRange()

Return a two-tuple indicating the (start,end) indices of this cell’s relay header.

Returns:tuple, int (start, end) indices of this cell’s relay header

relayPayloadRange()

Return a two-tuple indicating the (start,end) indices of this cell’s relay header.

Returns:tuple, int (start, end) indices of this cell’s relay payload

class RelayHeader(cmd, recognized, stream_id, digest, rpayload_len)

Bases: object

A simple container for relay header information.

FORMAT = '!B2sH4sH'

cmd = None

recognized = None

stream_id = None

digest = None

rpayload_len = None

getBytes()

Construct and return the byte string represented by this cell.

Returns:str byte string represented by this cell.

class cell.relay.RelayBeginDirCell(header)

Bases: cell.relay.RelayCell

Note

Not Implemented

class cell.relay.RelayBeginCell(header, rheader=None, addr=None, flags=None)

Bases: cell.relay.RelayCell

Note

tor-spec, Section 6.2

static make(circ_id, stream_id, request, flags=None, link_version=3)

Build and return a RelayBegin cell, filling in default values when possible.

Automatically create a default FixedLenCell.Header and RelayCell.RelayHeader.

Parameters:

• circ_id (int) – Circuit ID to use in this cell
• stream_id (int) – Stream ID to use in this cell
• request (oppy.util.ExitRequest) – destination this cell will request a connection to
• int flags (list,) – flags to use for this connection
• link_version (int) – Link Protocol version in use on this connection

Returns:

RelayBeginCell

getBytes(trimmed=False)

Build and return the raw byte string this cell represents.

Parameters:trimmed (bool) – If True, do not pad this cell’s payload. Returns:str raw byte string represented by this cell

class cell.relay.RelayConnectedCell(header, rheader=None, addr_type=None, addr=None, ttl=None)

Bases: cell.relay.RelayCell

Note

tor-spec, Section 6.2

getBytes(trimmed=False)

Build and return the raw byte string this cell represents.

Parameters:trimmed (bool) – if True, do not pad payload bytes Returns:str raw bytes this cell represents

class cell.relay.RelayDataCell(header, rheader=None, rpayload='')

Bases: cell.relay.RelayCell

Note

tor-spec, Section 6.2

static make(circ_id, stream_id, rpayload, link_version=3)

Construct and return a RelayData cell, using default values where possible.

Create a FixedLenCell.Header and a RelayCell.RelayHeader.

Parameters:

• circ_id (int) – Circuit ID to use in this cell
• stream_id (int) – Stream ID to use in this cell
• rpayload (str) – data to use as the relay payload
• link_version (int) – Link Protocol version in use

class cell.relay.RelayDropCell(header, rheader=None, rpayload='')

Bases: cell.relay.RelayCell

Note

tor-spec, Section 6.2

class cell.relay.RelayEndCell(header, rheader=None, reason=None, reason_data=None)

Bases: cell.relay.RelayCell

Note

tor-spec, Section 6.3

static make(circ_id, stream_id, reason=6, reason_data='', link_version=3)

Construct and return a RelayEnd cell, using default values where possible.

Create a FixedLenCell.Header and a RelayCell.RelayHeader.

Parameters:

• circ_id (int) – Circuit ID to use in this cell
• stream_id (int) – Stream ID to use in this cell
• reason (int) – Single byte that describes the reason this stream was closed
• reason_data (str) – with REASON_EXITPOLICY, this optional field may be filled in

Returns:

RelayEndCell

getBytes(trimmed=False)

Build and return the raw byte string this cell represents.

Parameters:trimmed (bool) – if True, do not pad payload bytes Returns:str raw byte string this cell represents

class cell.relay.RelayExtend2Cell(header, rheader=None, nspec=None, lspecs=None, htype=None, hlen=None, hdata=None)

Bases: cell.relay.RelayCell

Note

tor-spec, Section 5.1.2

static make(circ_id, stream_id=0, nspec=None, lspecs=None, htype=2, hlen=84, hdata='', link_version=3, early=True)

Construct and return a RelayExtend2Cell, using default values where possible.

Create a FixedLenCell.Header and a RelayCell.RelayHeader for use in this cell.

Note

oppy currently only supports the NTor handshake and will reject unrecognized htype’s and hlen’s.

Parameters:

• circ_id (int) – Circuit ID to use in this cell
• stream_id (int) – Stream ID to use in this cell (should be zero)
• nspec (int) – the number of Link Specifiers in this cell
• oppy.cell.util.LinkSpecifier lspecs (list,) – list of Link Specifiers to include in this cell
• htype (int) – Type of handshake in use
• hlen (int) – length of the handshake data field
• hdata (str) – handshake data (onion skin)
• link_version (int) – Link Protocol version in use
• early (bool) – if True, use a RELAY_EARLY cmd instead of RELAY cmd

Returns:

RelayExtend2Cell

getBytes(trimmed=False)

Build and return the raw byte string this cell represents.

Parameters:trimmed (bool) – if True, do not pad payload bytes Returns:str raw byte string this cell represents

class cell.relay.RelayExtended2Cell(header, rheader=None, hlen=None, hdata=None)

Bases: cell.relay.RelayCell

Note

tor-spec, Section 5.1, 5.1.2

getBytes(trimmed=False)

Build and return the raw byte string this cell represents.

Parameters:trimmed (bool) – if True, do not pad payload bytes Returns:str raw byte string this cell represents

class cell.relay.RelayExtendedCell(header)

Bases: cell.relay.RelayCell

Note

Not Implemented

class cell.relay.RelayExtendCell(header)

Bases: cell.relay.RelayCell

Note

Not Implemented

class cell.relay.RelayResolvedCell(header)

Bases: cell.relay.RelayCell

Note

Not Implemented

class cell.relay.RelayResolveCell(header)

Bases: cell.relay.RelayCell

Note

Not Implemented

class cell.relay.RelaySendMeCell(header, rheader=None, rpayload='')

Bases: cell.relay.RelayCell

Note

tor-spec, Section 7.3, 7.4

static make(circ_id, stream_id=0, link_version=3)

Construct and return a RelaySendMeCell, using default values where possible.

Create a FixedLenCell.Header and a RelayCell.RelayHeader for use in this cell.

Parameters:

• circ_id (int) – Circuit ID to use in this cell
• stream_id (int) – Stream ID to use in this cell. A Stream ID of zero indicates a ‘circuit-level’ SendMe cell, and a non-zero Stream ID indicates a ‘stream-level’ SendMe cell.
• link_version (int) – Link Protocol version in use

Returns:

RelaySendMeCell

class cell.relay.RelayTruncatedCell(header, rheader=None, reason=None)

Bases: cell.relay.RelayCell

Note

tor-spec, Section 5.4

getBytes(trimmed=False)

Build and return the raw byte string this cell represents.

Parameters:trimmed (bool) – if True, do not pad payload bytes Returns:str raw bytes this cell represents

class cell.relay.RelayTruncateCell(header, rheader=None, reason=None)

Bases: cell.relay.RelayCell

Note

Not Implemented