monero-python/monero/transaction/__init__.py

import binascii
import itertools
import operator
import re
import sha3
import six
import struct
import varint
import warnings
from ..address import address
from ..numbers import from_atomic, PaymentID
from .. import ed25519
from .. import exceptions
from .extra import ExtraParser

class Payment(object):
    """
    A payment base class, representing payment not associated with any
    :class:`Account <monero.account.Account>`.

    This class is not intended to be turned into objects by the user,
    it is used by backends.
    """
    payment_id = None
    amount = None
    timestamp = None
    transaction = None
    local_address = None
    note = ''

    _reprstr = "{} @ {} {:.12f} id={}"

    def __init__(self, **kwargs):
        self.amount = kwargs.pop('amount', self.amount)
        self.timestamp = kwargs.pop('timestamp', self.timestamp)
        self.payment_id = kwargs.pop('payment_id', self.payment_id)
        self.transaction = kwargs.pop('transaction', self.transaction)
        self.local_address = kwargs.pop('local_address', self.local_address)
        self.note = kwargs.pop('note', self.note)
        if len(kwargs):
            raise ValueError("Excessive arguments for {}: {}".format(type(self), kwargs))

    def __repr__(self):
        return self._reprstr.format(
            self.transaction.hash, self.transaction.height or 'pool', self.amount, self.payment_id)


class IncomingPayment(Payment):
    """
    An incoming payment (one that increases the balance of an
    :class:`Account <monero.account.Account>`)
    """
    _reprstr = "in: {} @ {} {:.12f} id={}"


class OutgoingPayment(Payment):
    """
    An outgoing payment (one that decreases the balance of an
    :class:`Account <monero.account.Account>`)
    """
    destinations = None

    def __init__(self, **kwargs):
        self.destinations = kwargs.pop('destinations', [])
        super(OutgoingPayment, self).__init__(**kwargs)

    _reprstr = "out: {} @ {} {:.12f} id={}"


class Transaction(object):
    """
    A Monero transaction. Identified by `hash`, it can be a part of a block of some `height`
    or not yet mined (`height` is `None` then).

    This class is not intended to be turned into objects by the user,
    it is used by backends.
    """
    hash = None
    fee = None
    height = None
    timestamp = None
    key = None
    blob = None
    confirmations = None
    output_indices = None
    json = None
    version = None
    pubkeys = None

    @property
    def is_coinbase(self):
        if self.json:
            return "gen" in self.json['vin'][0]
        raise exceptions.TransactionWithoutJSON(
            "Tx {:s} has no .json attribute and it cannot be determined "
            "if it's coinbase tx.".format(self.hash))

    @property
    def size(self):
        if not self.blob:
            raise exceptions.TransactionWithoutBlob(
                "Transaction has no blob, hence the size cannot be determined. "
                "Perhaps the backend prunes transaction data?")
        return len(self.blob)

    def __init__(self, **kwargs):
        self.hash = kwargs.get('hash', self.hash)
        self.fee = kwargs.get('fee', self.fee)
        self.height = kwargs.get('height', self.height)
        self.timestamp = kwargs.get('timestamp', self.timestamp)
        self.key = kwargs.get('key', self.key)
        self.blob = kwargs.get('blob', self.blob)
        self.confirmations = kwargs.get('confirmations', self.confirmations)
        self.output_indices = kwargs.get('output_indices', self.output_indices)
        self.json = kwargs.get('json', self.json)
        self.pubkeys = self.pubkeys or []
        if self.json:
            if "rct_signatures" in self.json:
                self.version = 2
            else:
                self.version = 1

    def outputs(self, wallet=None):
        """
        Returns a list of outputs. If wallet is given, decodes destinations and amounts
        for outputs directed to the wallet, provided that matching subaddresses have been
        already generated.
        """
        def _scan_pubkeys(svk, psk, stealth_address, amount, encamount):
            for keyidx, tx_key in enumerate(self.pubkeys):
                hsdata = b"".join(
                    [
                        ed25519.encodepoint(
                            ed25519.scalarmult(
                                ed25519.decodepoint(tx_key), ed25519.decodeint(svk) * 8
                            )
                        ),
                        varint.encode(idx),
                    ]
                )
                Hs_ur = sha3.keccak_256(hsdata).digest()

                # sc_reduce32:
                Hsint_ur = ed25519.decodeint(Hs_ur)
                Hsint = Hsint_ur % ed25519.l
                Hs = ed25519.encodeint(Hsint)

                k = ed25519.encodepoint(
                    ed25519.edwards_add(
                        ed25519.scalarmult_B(Hsint), ed25519.decodepoint(psk),
                    )
                )
                if k != stealth_address:
                    continue
                if not encamount:
                    # Tx ver 1
                    return Payment(
                        amount=amount,
                        timestamp=self.timestamp,
                        transaction=self,
                        local_address=addr)
                amount_hs = sha3.keccak_256(b"amount" + Hs).digest()
                xormask = amount_hs[:len(encamount)]
                dec_amount = bytearray(a ^ b for a, b in zip(*map(bytearray, (encamount, xormask))))
                int_amount = struct.unpack("<Q", dec_amount)[0]
                amount = from_atomic(int_amount)
                return Payment(
                        amount=amount,
                        timestamp=self.timestamp,
                        transaction=self,
                        local_address=addr)


        if not self.json:
            raise exceptions.TransactionWithoutJSON(
                'Tx {:s} has no .json attribute'.format(self.hash))

        if wallet:
            ep = ExtraParser(self.json["extra"])
            extra = ep.parse()
            self.pubkeys = extra.get("pubkeys", [])
            svk = binascii.unhexlify(wallet.view_key())
            # fetch before loop to save on calls; cast to list to preserve over multiple iterations
            addresses = list(
                itertools.chain(*map(operator.methodcaller("addresses"), wallet.accounts)))
        outs = []
        for idx, vout in enumerate(self.json['vout']):
            stealth_address = binascii.unhexlify(vout['target']['key'])
            encamount = None
            if self.version == 2 and not self.is_coinbase:
                encamount = binascii.unhexlify(
                    self.json["rct_signatures"]["ecdhInfo"][idx]["amount"]
                )
            payment = None
            amount = from_atomic(vout['amount'])
            if wallet:
                for addridx, addr in enumerate(addresses):
                    psk = binascii.unhexlify(addr.spend_key())
                    payment = _scan_pubkeys(svk, psk, stealth_address, amount, encamount)
                    if payment:
                        break
            outs.append(OneTimeOutput(
                stealth_address=vout['target']['key'],
                amount=payment.amount if payment else amount,
                index=self.output_indices[idx] if self.output_indices else None,
                height=self.height,
                transaction=self,
                payment=payment))
        return outs

    def __repr__(self):
        return self.hash


class OneTimeOutput(object):
    """
    A Monero one-time public output (A.K.A stealth address).
    Identified by `stealth_address`, or `index` and `amount`
    together, it can contain differing levels of information on an output.

    This class is not intended to be turned into objects by the user,
    it is used by backends.
    """
    stealth_address = None
    amount = None
    index = None
    height = None
    mask = None
    transaction = None
    payment = None
    unlocked = None

    def __init__(self, **kwargs):
        self.stealth_address = kwargs.get('stealth_address', self.stealth_address)
        self.amount = kwargs.get('amount', self.amount)
        self.index = kwargs.get('index', self.index)
        self.height = kwargs.get('height', self.height)
        self.mask = kwargs.get('mask', self.mask)
        self.transaction = kwargs.get('transaction', self.transaction)
        self.payment = kwargs.get('payment', self.payment)
        self.unlocked = kwargs.get('unlocked', self.unlocked)

    def __repr__(self):
        # Try to represent output as (index, amount) pair if applicable because there is no RPC
        # daemon command to lookup outputs by their stealth_address ;( 
        if self.stealth_address:
            return self.stealth_address
        else:
            return '(index={},amount={})'.format(self.index, self.amount)

    def __eq__(self, other):
        # Try to compare stealth_addresses, then try to compare (index,amount) pairs, else raise error
        if self.stealth_address and other.stealth_address:
            return self.stealth_address == other.stealth_address
        elif None not in (self.index, other.index, self.amount, other.amount):
            return self.index == other.index and self.amount == other.amount
        else:
            raise TypeError('Given one-time outputs (%r,%r) are not comparable'.format(self, other))

    def __ne__(self, other):
        return not(self == other)


class PaymentManager(object):
    """
    A payment query manager, handling either incoming or outgoing payments of
    an :class:`Account <monero.account.Account>`.

    This class is not intended to be turned into objects by the user,
    it is used by backends.
    """
    account_idx = 0
    backend = None

    def __init__(self, account_idx, backend, direction):
        self.account_idx = account_idx
        self.backend = backend
        self.direction = direction

    def __call__(self, **filterparams):
        fetch = self.backend.transfers_in if self.direction == 'in' else self.backend.transfers_out
        return fetch(self.account_idx, PaymentFilter(**filterparams))


def _validate_tx_id(txid):
    if not bool(re.compile('^[0-9a-f]{64}$').match(txid)):
        raise ValueError("Transaction ID must be a 64-character hexadecimal string, not "
            "'{}'".format(txid))
    return txid


class _ByHeight(object):
    """A helper class used as key in sorting of payments by height.
    Mempool goes on top, blockchain payments are ordered with descending block numbers.

    **WARNING:** Integer sorting is reversed here.
    """
    def __init__(self, pmt):
        self.pmt = pmt
    def _cmp(self, other):
        sh = self.pmt.transaction.height
        oh = other.pmt.transaction.height
        if sh is oh is None:
            return 0
        if sh is None:
            return 1
        if oh is None:
            return -1
        return (sh > oh) - (sh < oh)
    def __lt__(self, other):
        return self._cmp(other) > 0
    def __le__(self, other):
        return self._cmp(other) >= 0
    def __eq__(self, other):
        return self._cmp(other) == 0
    def __ge__(self, other):
        return self._cmp(other) <= 0
    def __gt__(self, other):
        return self._cmp(other) < 0
    def __ne__(self, other):
        return self._cmp(other) != 0


class PaymentFilter(object):
    """
    A helper class that filters payments retrieved by the backend.

    This class is not intended to be turned into objects by the user,
    it is used by backends.
    """
    def __init__(self, **filterparams):
        self.min_height = filterparams.pop('min_height', None)
        self.max_height = filterparams.pop('max_height', None)
        self.unconfirmed = filterparams.pop('unconfirmed', False)
        self.confirmed = filterparams.pop('confirmed', True)
        _local_address = filterparams.pop('local_address', None)
        _tx_id = filterparams.pop('tx_id', None)
        _payment_id = filterparams.pop('payment_id', None)
        if len(filterparams) > 0:
            raise ValueError("Excessive arguments for payment query: {}".format(filterparams))
        if self.unconfirmed and (self.min_height is not None or self.max_height is not None):
            warnings.warn("Height filtering (min_height/max_height) has been requested while "
                    "also asking for unconfirmed transactions. These are mutually exclusive. "
                    "As mempool transactions have no height at all, they will be excluded "
                    "from the result.",
                    RuntimeWarning)
        if _local_address is None:
            self.local_addresses = []
        else:
            if isinstance(_local_address, six.string_types) \
                or isinstance(_local_address, six.text_type):
                local_addresses = [_local_address]
            else:
                try:
                    iter(_local_address)
                    local_addresses = _local_address
                except TypeError:
                    local_addresses = [_local_address]
            self.local_addresses = list(map(address, local_addresses))
        if _tx_id is None:
            self.tx_ids = []
        else:
            if isinstance(_tx_id, six.string_types) or isinstance(_tx_id, six.text_type):
                tx_ids = [_tx_id]
            else:
                try:
                    iter(_tx_id)
                    tx_ids = _tx_id
                except TypeError:
                    tx_ids = [_tx_id]
            self.tx_ids = list(map(_validate_tx_id, tx_ids))
        if _payment_id is None:
            self.payment_ids = []
        else:
            if isinstance(_payment_id, six.string_types) or isinstance(_payment_id, six.text_type):
                payment_ids = [_payment_id]
            else:
                try:
                    iter(_payment_id)
                    payment_ids = _payment_id
                except TypeError:
                    payment_ids = [_payment_id]
            self.payment_ids = list(map(PaymentID, payment_ids))

    def check(self, payment):
        ht = payment.transaction.height
        if ht is None:
            if not self.unconfirmed:
                return False
            if self.min_height is not None or self.max_height is not None:
                # mempool txns are filtered out if any height range check is present
                return False
        else:
            if not self.confirmed:
                return False
            if self.min_height is not None and ht < self.min_height:
                return False
            if self.max_height is not None and ht > self.max_height:
                return False
        if self.payment_ids and payment.payment_id not in self.payment_ids:
            return False
        if self.tx_ids and payment.transaction.hash not in self.tx_ids:
            return False
        if self.local_addresses and payment.local_address not in self.local_addresses:
            return False
        return True

    def filter(self, payments):
        return sorted(
            filter(self.check, payments),
            key=_ByHeight)