Stem Docs

Network Status Documents

Network Status Documents

Parsing for Tor network status documents. This supports both the v2 and v3 dir-spec. Documents can be obtained from a few sources...

... and contain the following sections...

For a great graphical overview see Jordan Wright's chart describing the anatomy of the consensus.

Of these, the router status entry section can be quite large (on the order of hundreds of kilobytes). As such we provide a couple of methods for reading network status documents through parse_file(). For more information see DocumentHandler()...

from stem.descriptor import parse_file, DocumentHandler

with open('.tor/cached-consensus', 'rb') as consensus_file:
  # Processes the routers as we read them in. The routers refer to a document
  # with an unset 'routers' attribute.

  for router in parse_file(consensus_file, 'network-status-consensus-3 1.0', document_handler = DocumentHandler.ENTRIES):
    print router.nickname

Module Overview:

NetworkStatusDocument - Network status document
  |- NetworkStatusDocumentV2 - Version 2 network status document
  |- NetworkStatusDocumentV3 - Version 3 network status document
  +- BridgeNetworkStatusDocument - Version 3 network status document for bridges

KeyCertificate - Certificate used to authenticate an authority
DocumentSignature - Signature of a document by a directory authority
DirectoryAuthority - Directory authority as defined in a v3 network status document
class stem.descriptor.networkstatus.PackageVersion[source]

Bases: stem.descriptor.networkstatus.PackageVersion

Latest recommended version of a package that's available.

Variables:
  • name (str) -- name of the package
  • version (str) -- latest recommended version
  • url (str) -- package's url
  • digests (dict) -- mapping of digest types to their value
class stem.descriptor.networkstatus.SharedRandomnessCommitment[source]

Bases: stem.descriptor.networkstatus.SharedRandomnessCommitment

Directory authority's commitment for generating the next shared random value.

Variables:
  • version (int) -- shared randomness protocol version
  • algorithm (str) -- hash algorithm used to make the commitment
  • identity (str) -- authority's sha1 identity fingerprint
  • commit (str) -- base64 encoded commitment hash to the shared random value
  • reveal (str) -- base64 encoded commitment to the shared random value, None of not provided
class stem.descriptor.networkstatus.NetworkStatusDocument(contents, lazy_load=False)[source]

Bases: stem.descriptor.Descriptor

Common parent for network status documents.

class stem.descriptor.networkstatus.NetworkStatusDocumentV2(raw_content, validate=False)[source]

Bases: stem.descriptor.networkstatus.NetworkStatusDocument

Version 2 network status document. These have been deprecated and are no longer generated by Tor.

Variables:
  • routers (dict) -- fingerprints to RouterStatusEntryV2 contained in the document
  • version (int) -- * document version
  • hostname (str) -- * hostname of the authority
  • address (str) -- * authority's IP address
  • dir_port (int) -- * authority's DirPort
  • fingerprint (str) -- * authority's fingerprint
  • contact (str) -- * authority's contact information
  • signing_key (str) -- * authority's public signing key
  • client_versions (list) -- list of recommended client tor version strings
  • server_versions (list) -- list of recommended server tor version strings
  • published (datetime) -- * time when the document was published
  • options (list) -- * list of things that this authority decides
  • signing_authority (str) -- * name of the authority signing the document
  • signature (str) -- * authority's signature for the document

* attribute is either required when we're parsed with validation or has a default value, others are left as None if undefined

classmethod content(attr=None, exclude=(), sign=False)[source]
class stem.descriptor.networkstatus.NetworkStatusDocumentV3(raw_content, validate=False, default_params=True)[source]

Bases: stem.descriptor.networkstatus.NetworkStatusDocument

Version 3 network status document. This could be either a vote or consensus.

Variables:
  • routers (dict) -- fingerprint to RouterStatusEntryV3 mapping for relays contained in the document
  • version (int) -- * document version
  • version_flavor (str) -- * flavor associated with the document (such as 'microdesc')
  • is_consensus (bool) -- * True if the document is a consensus
  • is_vote (bool) -- * True if the document is a vote
  • is_microdescriptor (bool) -- * True if this is a microdescriptor flavored document, False otherwise
  • valid_after (datetime) -- * time when the consensus became valid
  • fresh_until (datetime) -- * time when the next consensus should be produced
  • valid_until (datetime) -- * time when this consensus becomes obsolete
  • vote_delay (int) -- * number of seconds allowed for collecting votes from all authorities
  • dist_delay (int) -- * number of seconds allowed for collecting signatures from all authorities
  • client_versions (list) -- list of recommended client tor versions
  • server_versions (list) -- list of recommended server tor versions
  • packages (list) -- * list of PackageVersion entries
  • known_flags (list) -- * list of Flag for the router's flags
  • params (dict) -- * dict of parameter(str) => value(int) mappings
  • directory_authorities (list) -- * list of DirectoryAuthority objects that have generated this document
  • signatures (list) -- * DocumentSignature of the authorities that have signed the document

Consensus Attributes:

Variables:
  • consensus_method (int) -- method version used to generate this consensus
  • bandwidth_weights (dict) -- dict of weight(str) => value(int) mappings
  • shared_randomness_current_value (str) -- base64 encoded current shared random value
  • shared_randomness_previous_value (str) -- base64 encoded last shared random value

Vote Attributes:

Variables:
  • consensus_methods (list) -- list of ints for the supported method versions
  • published (datetime) -- time when the document was published
  • flag_thresholds (dict) -- * mapping of internal performance thresholds used while making the vote, values are ints or floats
  • recommended_client_protocols (dict) -- recommended protocols for clients
  • recommended_relay_protocols (dict) -- recommended protocols for relays
  • required_client_protocols (dict) -- required protocols for clients
  • required_relay_protocols (dict) -- required protocols for relays

* attribute is either required when we're parsed with validation or has a default value, others are left as None if undefined

Changed in version 1.4.0: Added the packages attribute.

Changed in version 1.5.0: Added the is_shared_randomness_participate, shared_randomness_commitments, shared_randomness_previous_reveal_count, shared_randomness_previous_value, shared_randomness_current_reveal_count, and shared_randomness_current_value attributes.

Changed in version 1.6.0: Added the recommended_client_protocols, recommended_relay_protocols, required_client_protocols, and required_relay_protocols.

Changed in version 1.6.0: The shared randomness attributes were misdocumented in the tor spec and as such never set. They're now an attribute of directory_authorities.

HEADER_PARSER_FOR_LINE = {'valid-after': <function _parse at 0x7f0ee2217398>, 'server-versions': <function _parse at 0x7f0ee2217578>, 'shared-rand-previous-value': <function _parse_shared_rand_previous_value at 0x7f0ee22172a8>, 'network-status-version': <function _parse_header_network_status_version_line at 0x7f0ee2215b18>, 'consensus-method': <function _parse_header_consensus_method_line at 0x7f0ee2215de8>, 'client-versions': <function _parse at 0x7f0ee2217500>, 'known-flags': <function _parse at 0x7f0ee2217668>, 'voting-delay': <function _parse_header_voting_delay_line at 0x7f0ee2215e60>, 'shared-rand-current-value': <function _parse_shared_rand_current_value at 0x7f0ee2217320>, 'package': <function _parse_package_line at 0x7f0ee22171b8>, 'params': <function _parse_header_parameters_line at 0x7f0ee2217050>, 'recommended-relay-protocols': <function _parse at 0x7f0ee22178c0>, 'fresh-until': <function _parse at 0x7f0ee2217410>, 'valid-until': <function _parse at 0x7f0ee2217488>, 'published': <function _parse at 0x7f0ee2215938>, 'required-client-protocols': <function _parse at 0x7f0ee2217938>, 'vote-status': <function _parse_header_vote_status_line at 0x7f0ee2215cf8>, 'required-relay-protocols': <function _parse at 0x7f0ee22179b0>, 'flag-thresholds': <function _parse_header_flag_thresholds_line at 0x7f0ee2215f50>, 'consensus-methods': <function _parse_header_consensus_methods_line at 0x7f0ee2215d70>, 'recommended-client-protocols': <function _parse at 0x7f0ee2217848>}
FOOTER_PARSER_FOR_LINE = {'directory-signature': <function _parse_footer_directory_signature_line at 0x7f0ee2217140>, 'bandwidth-weights': <function _parse at 0x7f0ee2217758>, 'directory-footer': <function _parse_directory_footer_line at 0x7f0ee22170c8>}
classmethod content(attr=None, exclude=(), sign=False, authorities=None, routers=None)[source]
classmethod create(attr=None, exclude=(), validate=True, sign=False, authorities=None, routers=None)[source]
validate_signatures(key_certs)[source]

Validates we're properly signed by the signing certificates.

New in version 1.6.0.

Parameters:key_certs (list) -- KeyCertificates to validate the consensus against
Raises :ValueError if an insufficient number of valid signatures are present.
get_unrecognized_lines()[source]
meets_consensus_method(method)[source]

Checks if we meet the given consensus-method. This works for both votes and consensuses, checking our 'consensus-method' and 'consensus-methods' entries.

Parameters:method (int) -- consensus-method to check for
Returns:True if we meet the given consensus-method, and False otherwise
class stem.descriptor.networkstatus.DirectoryAuthority(raw_content, validate=False, is_vote=False)[source]

Bases: stem.descriptor.Descriptor

Directory authority information obtained from a v3 network status document.

Authorities can optionally use a legacy format. These are no longer found in practice, but have the following differences...

  • The authority's nickname ends with '-legacy'.
  • There's no contact or vote_digest attribute.
Variables:
  • nickname (str) -- * authority's nickname
  • v3ident (str) -- * identity key fingerprint used to sign votes and consensus
  • hostname (str) -- * hostname of the authority
  • address (str) -- * authority's IP address
  • dir_port (int) -- * authority's DirPort
  • or_port (int) -- * authority's ORPort
  • is_legacy (bool) -- * if the authority's using the legacy format
  • contact (str) -- contact information, this is included if is_legacy is False

Consensus Attributes:

Variables:vote_digest (str) -- digest of the authority that contributed to the consensus, this is included if is_legacy is False

Vote Attributes:

Variables:
  • legacy_dir_key (str) -- fingerprint of and obsolete identity key
  • key_certificate (stem.descriptor.networkstatus.KeyCertificate) -- * authority's key certificate
  • is_shared_randomness_participate (bool) -- * True if this authority participates in establishing a shared random value, False otherwise
  • shared_randomness_commitments (list) -- * list of SharedRandomnessCommitment entries
  • shared_randomness_previous_reveal_count (int) -- number of commitments used to generate the last shared random value
  • shared_randomness_previous_value (str) -- base64 encoded last shared random value
  • shared_randomness_current_reveal_count (int) -- number of commitments used to generate the current shared random value
  • shared_randomness_current_value (str) -- base64 encoded current shared random value

* mandatory attribute

Changed in version 1.4.0: Renamed our 'fingerprint' attribute to 'v3ident' (prior attribute exists for backward compatability, but is deprecated).

Changed in version 1.6.0: Added the is_shared_randomness_participate, shared_randomness_commitments, shared_randomness_previous_reveal_count, shared_randomness_previous_value, shared_randomness_current_reveal_count, and shared_randomness_current_value attributes.

classmethod create(attr=None, exclude=(), validate=True, sign=False, is_vote=False)[source]
classmethod content(attr=None, exclude=(), sign=False, is_vote=False)[source]
class stem.descriptor.networkstatus.KeyCertificate(raw_content, validate=False)[source]

Bases: stem.descriptor.Descriptor

Directory key certificate for a v3 network status document.

Variables:
  • version (int) -- * version of the key certificate
  • address (str) -- authority's IP address
  • dir_port (int) -- authority's DirPort
  • fingerprint (str) -- * authority's fingerprint
  • identity_key (str) -- * long term authority identity key
  • published (datetime) -- * time when this key was generated
  • expires (datetime) -- * time after which this key becomes invalid
  • signing_key (str) -- * directory server's public signing key
  • crosscert (str) -- signature made using certificate's signing key
  • certification (str) -- * signature of this key certificate signed with the identity key

* mandatory attribute

classmethod content(attr=None, exclude=(), sign=False)[source]
class stem.descriptor.networkstatus.DocumentSignature(method, identity, key_digest, signature, validate=False)[source]

Bases: object

Directory signature of a v3 network status document.

Variables:
  • method (str) -- algorithm used to make the signature
  • identity (str) -- fingerprint of the authority that made the signature
  • key_digest (str) -- digest of the signing key
  • signature (str) -- document signature
Parameters:

validate (bool) -- checks validity if True

Raises :

ValueError if a validity check fails

class stem.descriptor.networkstatus.BridgeNetworkStatusDocument(raw_content, validate=False)[source]

Bases: stem.descriptor.networkstatus.NetworkStatusDocument

Network status document containing bridges. This is only available through the metrics site.

Variables:
  • routers (dict) -- fingerprint to RouterStatusEntryV3 mapping for relays contained in the document
  • published (datetime) -- time when the document was published