zeth.core.wallet.Wallet Class Reference

Public Member Functions
def	__init__ (self, Any mixer_instance, str username, str wallet_dir, ZethAddressPriv secret_address, ITreeHash tree_hash)
Optional[ZethNoteDescription]	receive_note (self, int comm_addr, MixOutputEvents out_ev, PairingParameters pp)
List[ZethNoteDescription]	receive_notes (self, List[MixOutputEvents] output_events, PairingParameters pp)
List[str]	mark_nullifiers_used (self, List[bytes] nullifiers)
Iterator[Tuple[int, str, EtherValue]]	note_summaries (self)
Iterator[Tuple[int, str, EtherValue]]	spent_note_summaries (self)
int	get_next_block (self)
None	update_and_save_state (self, int next_block)
ZethNoteDescription	find_note (self, str note_id)

Public Attributes
	mixer_instance
	username
	wallet_dir
	a_sk
	k_sk_receiver
	state_file
	state
	merkle_tree
	merkle_tree_changed
	next_addr

Detailed Description

Very simple class to track the list of notes owned by a Zeth user.

Note: this class does not store the notes in encrypted form, and encodes
some information (including value) in the filename. It is a proof of
concept implementation and NOT intended to be secure against intruders who
have access to the file system. However, we expect that a secure
implementation could expose similar interface and functionality.

Definition at line 111 of file wallet.py.

Constructor & Destructor Documentation

__init__()

def zeth.core.wallet.Wallet.__init__	(		self,
		Any	mixer_instance,
		str	username,
		str	wallet_dir,
		ZethAddressPriv	secret_address,
		ITreeHash	tree_hash
	)

Definition at line 121 of file wallet.py.

    def __init__(
            self,
            mixer_instance: Any,
            username: str,
            wallet_dir: str,
            secret_address: ZethAddressPriv,
            tree_hash: ITreeHash):
        # k_sk_receiver: EncryptionSecretKey):
        assert "_" not in username
        self.mixer_instance = mixer_instance
        self.username = username
        self.wallet_dir = wallet_dir
        self.a_sk = secret_address.a_sk
        self.k_sk_receiver = secret_address.k_sk
        self.state_file = join(wallet_dir, f"state_{username}")
        self.state = _load_state_or_default(self.state_file)
        _ensure_dir(join(self.wallet_dir, SPENT_SUBDIRECTORY))
        self.merkle_tree = PersistentMerkleTree.open(
            join(wallet_dir, MERKLE_TREE_FILE),
            int(math.pow(2, ZETH_MERKLE_TREE_DEPTH)),
            tree_hash)
        self.merkle_tree_changed = False
        self.next_addr = self.merkle_tree.get_num_entries()
 

Member Function Documentation

find_note()

ZethNoteDescription zeth.core.wallet.Wallet.find_note	(		self,
		str	note_id
	)

Definition at line 234 of file wallet.py.

    def find_note(self, note_id: str) -> ZethNoteDescription:
        note_file = self._find_note_file(note_id)
        if not note_file:
            raise Exception(f"no note with id {note_id}")
        with open(note_file, "r") as note_f:
            return ZethNoteDescription.from_json(note_f.read())
 

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get_next_block()

int zeth.core.wallet.Wallet.get_next_block

(

self

)

Definition at line 226 of file wallet.py.

    def get_next_block(self) -> int:
        return self.state.next_block
 

mark_nullifiers_used()

List[str] zeth.core.wallet.Wallet.mark_nullifiers_used	(		self,
		List[bytes]	nullifiers
	)

Process nullifiers, marking any of our notes that they spend.

Definition at line 198 of file wallet.py.

    def mark_nullifiers_used(self, nullifiers: List[bytes]) -> List[str]:
        """
        Process nullifiers, marking any of our notes that they spend.
        """
        commits: List[str] = []
        for nullifier in nullifiers:
            nullifier_hex = nullifier.hex()
            short_commit = self.state.nullifier_map.get(nullifier_hex, None)
            if short_commit:
                commits.append(short_commit)
                self._mark_note_spent(nullifier_hex, short_commit)
 
        return commits
 

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note_summaries()

Iterator[Tuple[int, str, EtherValue]] zeth.core.wallet.Wallet.note_summaries

(

self

)

Returns simple information that can be efficiently read from the notes
store.

Definition at line 212 of file wallet.py.

    def note_summaries(self) -> Iterator[Tuple[int, str, EtherValue]]:
        """
        Returns simple information that can be efficiently read from the notes
        store.
        """
        return self._decode_note_files_in_dir(self.wallet_dir)
 

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receive_note()

Optional[ZethNoteDescription] zeth.core.wallet.Wallet.receive_note	(		self,
		int	comm_addr,
		MixOutputEvents	out_ev,
		PairingParameters	pp
	)

Definition at line 145 of file wallet.py.

    def receive_note(
            self,
            comm_addr: int,
            out_ev: MixOutputEvents,
            pp: PairingParameters) -> Optional[ZethNoteDescription]:
        # Check this output event to see if it belongs to this wallet.
        our_note = receive_note(out_ev, self.k_sk_receiver)
        if our_note is None:
            return None
 
        (commit, note) = our_note
        if not _check_note(commit, note, pp):
            return None
 
        note_desc = ZethNoteDescription(note, comm_addr, commit)
        self._write_note(note_desc)
 
        # Add the nullifier to the map in the state file
        nullifier = compute_nullifier(note_desc.note, self.a_sk)
        self.state.nullifier_map[nullifier.hex()] = \
            short_commitment(commit)
        return note_desc
 

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receive_notes()

List[ZethNoteDescription] zeth.core.wallet.Wallet.receive_notes	(		self,
		List[MixOutputEvents]	output_events,
		PairingParameters	pp
	)

Decrypt any notes we can, verify them as being valid, and store them in
the database.

Definition at line 168 of file wallet.py.

    def receive_notes(
            self,
            output_events: List[MixOutputEvents],
            pp: PairingParameters) -> List[ZethNoteDescription]:
        """
        Decrypt any notes we can, verify them as being valid, and store them in
        the database.
        """
        new_notes = []
 
        self.merkle_tree_changed = len(output_events) != 0
        for out_ev in output_events:
            print(
                f"wallet.receive_notes: idx:{self.next_addr}, " +
                f"comm:{out_ev.commitment[:8].hex()}")
 
            # All commitments must be added to the tree in order.
            self.merkle_tree.insert(out_ev.commitment)
            note_desc = self.receive_note(self.next_addr, out_ev, pp)
            if note_desc is not None:
                new_notes.append(note_desc)
 
            self.next_addr = self.next_addr + 1
 
        # Record full set of notes seen to keep an estimate of the total in the
        # mixer.
        self.state.num_notes = self.state.num_notes + len(output_events)
 
        return new_notes
 

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spent_note_summaries()

Iterator[Tuple[int, str, EtherValue]] zeth.core.wallet.Wallet.spent_note_summaries

(

self

)

Returns simple info from note filenames in the spent directory.

Definition at line 219 of file wallet.py.

    def spent_note_summaries(self) -> Iterator[Tuple[int, str, EtherValue]]:
        """
        Returns simple info from note filenames in the spent directory.
        """
        return self._decode_note_files_in_dir(
            join(self.wallet_dir, SPENT_SUBDIRECTORY))
 

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update_and_save_state()

None zeth.core.wallet.Wallet.update_and_save_state	(		self,
		int	next_block
	)

Definition at line 229 of file wallet.py.

    def update_and_save_state(self, next_block: int) -> None:
        self.state.next_block = next_block
        _save_state(self.state_file, self.state)
        self._save_merkle_tree_if_changed()
 

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Member Data Documentation

a_sk

zeth.core.wallet.Wallet.a_sk

Definition at line 127 of file wallet.py.

k_sk_receiver

zeth.core.wallet.Wallet.k_sk_receiver

Definition at line 128 of file wallet.py.

merkle_tree

zeth.core.wallet.Wallet.merkle_tree

Definition at line 132 of file wallet.py.

merkle_tree_changed

zeth.core.wallet.Wallet.merkle_tree_changed

Definition at line 136 of file wallet.py.

mixer_instance

zeth.core.wallet.Wallet.mixer_instance

Definition at line 124 of file wallet.py.

next_addr

zeth.core.wallet.Wallet.next_addr

Definition at line 137 of file wallet.py.

state

zeth.core.wallet.Wallet.state

Definition at line 130 of file wallet.py.

state_file

zeth.core.wallet.Wallet.state_file

Definition at line 129 of file wallet.py.

username

zeth.core.wallet.Wallet.username

Definition at line 125 of file wallet.py.

wallet_dir

zeth.core.wallet.Wallet.wallet_dir

Definition at line 126 of file wallet.py.

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The documentation for this class was generated from the following file:

• /home/runner/work/zeth/zeth/client/zeth/core/wallet.py