How to use the tink.python.core.crypto_format function in tink

def decrypt(self, ciphertext: bytes, associated_data: bytes) -> bytes:
    if len(ciphertext) > crypto_format.NON_RAW_PREFIX_SIZE:
      prefix = ciphertext[:crypto_format.NON_RAW_PREFIX_SIZE]
      ciphertext_no_prefix = ciphertext[crypto_format.NON_RAW_PREFIX_SIZE:]
      for entry in self._primitive_set.primitive_from_identifier(prefix):
        try:
          return entry.primitive.decrypt(ciphertext_no_prefix,
                                         associated_data)
        except tink_error.TinkError as e:
          logging.info(
              'ciphertext prefix matches a key, but cannot decrypt: %s', e)
    # Let's try all RAW keys.
    for entry in self._primitive_set.raw_primitives():
      try:
        return entry.primitive.decrypt(ciphertext, associated_data)
      except tink_error.TinkError as e:
        pass
    # nothing works.
    raise tink_error.TinkError('Decryption failed.')

def verify(self, signature: bytes, data: bytes):
    """Verifies that signature is a digital signature for data.

    Args:
      signature: The signature bytes to be checked.
      data: The data bytes to be checked.

    Raises:
      tink_error.TinkError if the verification fails.
    """
    if len(signature) <= crypto_format.NON_RAW_PREFIX_SIZE:
      # This also rejects raw signatures with size of 4 bytes or fewer.
      # We're not aware of any schemes that output signatures that small.
      raise tink_error.TinkError('signature too short')

    key_id = signature[:crypto_format.NON_RAW_PREFIX_SIZE]
    raw_sig = signature[crypto_format.NON_RAW_PREFIX_SIZE:]

    for entry in self._primitive_set.primitive_from_identifier(key_id):
      try:
        if entry.output_prefix_type == tink_pb2.LEGACY:
          entry.primitive.verify(raw_sig,
                                 data + crypto_format.LEGACY_START_BYTE)
        else:
          entry.primitive.verify(raw_sig, data)
        # Signature is valid, we can return
        return

def decrypt_deterministically(self, ciphertext: bytes,
                                associated_data: bytes) -> bytes:
    if len(ciphertext) > crypto_format.NON_RAW_PREFIX_SIZE:
      prefix = ciphertext[:crypto_format.NON_RAW_PREFIX_SIZE]
      ciphertext_no_prefix = ciphertext[crypto_format.NON_RAW_PREFIX_SIZE:]
      for entry in self._primitive_set.primitive_from_identifier(prefix):
        try:
          return entry.primitive.decrypt_deterministically(ciphertext_no_prefix,
                                                           associated_data)
        except tink_error.TinkError as e:
          logging.info(
              'ciphertext prefix matches a key, but cannot decrypt: %s', e)
    # Let's try all RAW keys.
    for entry in self._primitive_set.raw_primitives():
      try:
        return entry.primitive.decrypt_deterministically(ciphertext,
                                                         associated_data)
      except tink_error.TinkError as e:
        pass

def decrypt(self, ciphertext: bytes, context_info: bytes) -> bytes:
    if len(ciphertext) > crypto_format.NON_RAW_PREFIX_SIZE:
      prefix = ciphertext[:crypto_format.NON_RAW_PREFIX_SIZE]
      ciphertext_no_prefix = ciphertext[crypto_format.NON_RAW_PREFIX_SIZE:]
      for entry in self._primitive_set.primitive_from_identifier(prefix):
        try:
          return entry.primitive.decrypt(ciphertext_no_prefix,
                                         context_info)
        except tink_error.TinkError as e:
          logging.info(
              'ciphertext prefix matches a key, but cannot decrypt: %s', e)
    # Let's try all RAW keys.
    for entry in self._primitive_set.raw_primitives():
      try:
        return entry.primitive.decrypt(ciphertext, context_info)
      except tink_error.TinkError as e:
        pass
    # nothing works.

def decrypt(self, ciphertext: bytes, associated_data: bytes) -> bytes:
    if len(ciphertext) > crypto_format.NON_RAW_PREFIX_SIZE:
      prefix = ciphertext[:crypto_format.NON_RAW_PREFIX_SIZE]
      ciphertext_no_prefix = ciphertext[crypto_format.NON_RAW_PREFIX_SIZE:]
      for entry in self._primitive_set.primitive_from_identifier(prefix):
        try:
          return entry.primitive.decrypt(ciphertext_no_prefix,
                                         associated_data)
        except tink_error.TinkError as e:
          logging.info(
              'ciphertext prefix matches a key, but cannot decrypt: %s', e)
    # Let's try all RAW keys.
    for entry in self._primitive_set.raw_primitives():
      try:
        return entry.primitive.decrypt(ciphertext, associated_data)
      except tink_error.TinkError as e:
        pass
    # nothing works.

def decrypt(self, ciphertext: bytes, context_info: bytes) -> bytes:
    if len(ciphertext) > crypto_format.NON_RAW_PREFIX_SIZE:
      prefix = ciphertext[:crypto_format.NON_RAW_PREFIX_SIZE]
      ciphertext_no_prefix = ciphertext[crypto_format.NON_RAW_PREFIX_SIZE:]
      for entry in self._primitive_set.primitive_from_identifier(prefix):
        try:
          return entry.primitive.decrypt(ciphertext_no_prefix,
                                         context_info)
        except tink_error.TinkError as e:
          logging.info(
              'ciphertext prefix matches a key, but cannot decrypt: %s', e)
    # Let's try all RAW keys.
    for entry in self._primitive_set.raw_primitives():
      try:
        return entry.primitive.decrypt(ciphertext, context_info)
      except tink_error.TinkError as e:
        pass
    # nothing works.
    raise tink_error.TinkError('Decryption failed.')

def decrypt_deterministically(self, ciphertext: bytes,
                                associated_data: bytes) -> bytes:
    if len(ciphertext) > crypto_format.NON_RAW_PREFIX_SIZE:
      prefix = ciphertext[:crypto_format.NON_RAW_PREFIX_SIZE]
      ciphertext_no_prefix = ciphertext[crypto_format.NON_RAW_PREFIX_SIZE:]
      for entry in self._primitive_set.primitive_from_identifier(prefix):
        try:
          return entry.primitive.decrypt_deterministically(ciphertext_no_prefix,
                                                           associated_data)
        except tink_error.TinkError as e:
          logging.info(
              'ciphertext prefix matches a key, but cannot decrypt: %s', e)
    # Let's try all RAW keys.
    for entry in self._primitive_set.raw_primitives():
      try:
        return entry.primitive.decrypt_deterministically(ciphertext,
                                                         associated_data)
      except tink_error.TinkError as e:
        pass
    # nothing works.
    raise tink_error.TinkError('Decryption failed.')

"""Verifies that signature is a digital signature for data.

    Args:
      signature: The signature bytes to be checked.
      data: The data bytes to be checked.

    Raises:
      tink_error.TinkError if the verification fails.
    """
    if len(signature) <= crypto_format.NON_RAW_PREFIX_SIZE:
      # This also rejects raw signatures with size of 4 bytes or fewer.
      # We're not aware of any schemes that output signatures that small.
      raise tink_error.TinkError('signature too short')

    key_id = signature[:crypto_format.NON_RAW_PREFIX_SIZE]
    raw_sig = signature[crypto_format.NON_RAW_PREFIX_SIZE:]

    for entry in self._primitive_set.primitive_from_identifier(key_id):
      try:
        if entry.output_prefix_type == tink_pb2.LEGACY:
          entry.primitive.verify(raw_sig,
                                 data + crypto_format.LEGACY_START_BYTE)
        else:
          entry.primitive.verify(raw_sig, data)
        # Signature is valid, we can return
        return
      except tink_error.TinkError as err:
        logging.info('signature prefix matches a key, but cannot verify: %s',
                     err)

    # No matching key succeeded with verification, try all RAW keys
    for entry in self._primitive_set.raw_primitives():