iota/crypto/kerl/pykerl.py
def squeeze(self, trits, offset=0, length=None):
        # type: (MutableSequence[int], int, Optional[int]) -> None
        """
        Squeeze trits from the sponge into a buffer.

        :param trits:
            Buffer that will hold the squeezed trits.

            IMPORTANT:  If ``trits`` is too small, it will be extended!

        :param offset:
            Starting offset in ``trits``.

        :param length:
            Number of trits to squeeze from the sponge.

            If not specified, defaults to :py:data:`TRIT_HASH_LENGTH`
            (i.e., by default, we will try to squeeze exactly 1 hash).
        """
        # Pad input if necessary, so that it can be divided evenly into
        # hashes.
        pad = ((len(trits) % TRIT_HASH_LENGTH) or TRIT_HASH_LENGTH)
        trits += [0] * (TRIT_HASH_LENGTH - pad)

        if length is None:
            # By default, we will try to squeeze one hash.
            # Note that this is different than ``absorb``.
            length = len(trits) or TRIT_HASH_LENGTH

        if length < 1:
            raise with_context(
                exc=ValueError('Invalid length passed to ``squeeze``.'),

                context={
                    'trits': trits,
                    'offset': offset,
                    'length': length,
                },
            )

        while offset < length:
            unsigned_hash = self.k.digest()

            if PY2:
                unsigned_hash = map(ord, unsigned_hash)  # type: ignore

            signed_hash = [conv.convert_sign(b) for b in unsigned_hash]

            trits_from_hash = conv.convertToTrits(signed_hash)
            trits_from_hash[TRIT_HASH_LENGTH - 1] = 0

            stop = min(TRIT_HASH_LENGTH, length - offset)
            trits[offset:offset + stop] = trits_from_hash[0:stop]

            flipped_bytes = bytearray(
                conv.convert_sign(~b) for b in unsigned_hash
            )

            # Reset internal state before feeding back in.
            self.reset()
            self.k.update(flipped_bytes)

            offset += TRIT_HASH_LENGTH
def squeeze(self, trits, offset=0, length=None):
        # type: (MutableSequence[int], int, Optional[int]) -> None
        """
        Squeeze trits from the sponge into a buffer.

        :param trits:
            Buffer that will hold the squeezed trits.

            IMPORTANT:  If ``trits`` is too small, it will be extended!

        :param offset:
            Starting offset in ``trits``.

        :param length:
            Number of trits to squeeze from the sponge.

            If not specified, defaults to :py:data:`TRIT_HASH_LENGTH`
            (i.e., by default, we will try to squeeze exactly 1 hash).
        """
        # Pad input if necessary, so that it can be divided evenly into
        # hashes.
        pad = ((len(trits) % TRIT_HASH_LENGTH) or TRIT_HASH_LENGTH)
        trits += [0] * (TRIT_HASH_LENGTH - pad)

        if length is None:
            # By default, we will try to squeeze one hash.
            # Note that this is different than ``absorb``.
            length = len(trits) or TRIT_HASH_LENGTH

        if length < 1:
            raise with_context(
                exc=ValueError('Invalid length passed to ``squeeze``.'),

                context={
                    'trits': trits,
                    'offset': offset,
                    'length': length,
                },
            )

        while offset < length:
            unsigned_hash = self.k.digest()

            if PY2:
                unsigned_hash = map(ord, unsigned_hash)  # type: ignore

            signed_hash = [conv.convert_sign(b) for b in unsigned_hash]

            trits_from_hash = conv.convertToTrits(signed_hash)
            trits_from_hash[TRIT_HASH_LENGTH - 1] = 0

            stop = min(TRIT_HASH_LENGTH, length - offset)
            trits[offset:offset + stop] = trits_from_hash[0:stop]

            flipped_bytes = bytearray(
                conv.convert_sign(~b) for b in unsigned_hash
            )

            # Reset internal state before feeding back in.
            self.reset()
            self.k.update(flipped_bytes)

            offset += TRIT_HASH_LENGTH
Squeeze trits from the sponge into a buffer.

        :param trits:
            Buffer that will hold the squeezed trits.

            IMPORTANT:  If ``trits`` is too small, it will be extended!

        :param offset:
            Starting offset in ``trits``.

        :param length:
            Number of trits to squeeze from the sponge.

            If not specified, defaults to :py:data:`TRIT_HASH_LENGTH`
            (i.e., by default, we will try to squeeze exactly 1 hash).