Source code for arkouda.security

import json
import os
import platform
import secrets
from collections import defaultdict
from os.path import expanduser
from pathlib import Path

from typeguard import typechecked

from arkouda import io_util

username_tokenizer = defaultdict(lambda x: x.split("/"))  # type: ignore
username_tokenizer["Windows"] = lambda x: x.split("\\")
username_tokenizer["Linux"] = lambda x: x.split("/")
username_tokenizer["Darwin"] = lambda x: x.split("/")




@typechecked
def generate_token(length: int = 32) -> str:
    """
    Uses the secrets.token_hex() method to generate a
    a hexidecimal token

    Parameters
    ----------
    length : int
        The desired length of token

    Returns
    -------
    str
        The hexidecimal string generated by Python

    Notes
    -----
    This method uses the Python secrets.token_hex method
    """
    return secrets.token_hex(length // 2)





def get_home_directory() -> str:
    """
    A platform-independent means of finding path to
    the current user's home directory

    Returns
    -------
    str
        The user's home directory path

    Notes
    -----
    This method uses the Python os.path.expanduser method
    to retrieve the user's home directory
    """
    return expanduser("~")





def get_arkouda_client_directory() -> Path:
    """
    A platform-independent means of finding path to
    the current user's .arkouda directory where artifacts
    such as server access tokens are stored.

    Returns
    -------
    Path
        Path corresponding to the user's .arkouda directory path

    Notes
    -----
    The default implementation is to place the .arkouda
    directory in the current user's home directory. The
    default can be overridden by setting the ARKOUDA_CLIENT_DIRECTORY
    environment variable.  It is important this is not the same location
    as the server's token directory as the file format is different.
    """
    arkouda_parent_dir = os.getenv("ARKOUDA_CLIENT_DIRECTORY")
    if not arkouda_parent_dir:
        arkouda_parent_dir = get_home_directory()
    return io_util.get_directory("{}{}.arkouda".format(arkouda_parent_dir, os.sep)).absolute()





def get_username() -> str:
    """
    A platform-independent means of retrieving the current
    user's username for the host system.

    Returns
    -------
    str
        The username in the form of string

    Raises
    ------
    EnvironmentError
        Raised if the host OS is unsupported

    Notes
    -----
    The currently supported operating systems are Windows, Linux,
    and MacOS AKA Darwin
    """
    try:
        u_tokens = username_tokenizer[platform.system()](get_home_directory())
    except KeyError as ke:
        raise EnvironmentError(f"Unsupported OS: {ke}")
    return u_tokens[-1]





@typechecked
def generate_username_token_json(token: str) -> str:
    """
    Generates a JSON object encapsulating the user's username
    and token for connecting to an arkouda server with basic
    authentication enabled

    Parameters
    ----------
    token : string
        The token to be used to access arkouda server

    Returns
    -------
    str
        The JSON-formatted string encapsulating username and token
    """
    return json.dumps({"username": get_username(), "token": token})