aboutsummaryrefslogtreecommitdiff
path: root/gn_auth/__init__.py
blob: b3df0702b7d23ec9f7bf18905ab98eb61abb1493 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
"""Application initialisation module."""
import os
import sys
from pathlib import Path
from typing import Optional, Callable

from flask import Flask
from flask_cors import CORS
from authlib.jose import JsonWebKey

from gn_auth.misc_views import misc
from gn_auth.auth.views import oauth2

from gn_auth.auth.authentication.oauth2.server import setup_oauth2_server

from . import settings
from .errors import register_error_handlers

class ConfigurationError(Exception):
    """Raised in case of a configuration error."""

def check_mandatory_settings(app: Flask) -> None:
    """Verify that mandatory settings are defined in the application"""
    undefined = tuple(
        setting for setting in (
            "SECRET_KEY", "SQL_URI", "AUTH_DB", "AUTH_MIGRATIONS",
            "OAUTH2_SCOPE", "SSL_PRIVATE_KEY", "CLIENTS_SSL_PUBLIC_KEYS_DIR")
        if not ((setting in app.config) and bool(app.config[setting])))
    if len(undefined) > 0:
        raise ConfigurationError(
            "You must provide (valid) values for the following settings: " +
            "\n\t* " + "\n\t* ".join(undefined))

def override_settings_with_envvars(
        app: Flask, ignore: tuple[str, ...]=tuple()) -> None:
    """Override settings in `app` with those in ENVVARS"""
    for setting in (key for key in app.config if key not in ignore):
        app.config[setting] = os.environ.get(setting) or app.config[setting]


def load_secrets_conf(app: Flask) -> None:
    """Load the secrets file."""
    secretsfile = app.config.get("GN_AUTH_SECRETS")
    if ((not secretsfile is None) and (bool(secretsfile.strip()))):
        secretsfile = Path(secretsfile.strip()).absolute()
        app.config["GN_AUTH_SECRETS"] = secretsfile
        if not secretsfile.exists():
            raise ConfigurationError(
                f"The file '{secretsfile}' does not exist. "
                "You must provide a path to an existing secrets file.")
        app.config.from_pyfile(secretsfile)


def parse_ssl_keys(app):
    """Parse the SSL keys."""
    def __parse_key__(keypath: Path) -> JsonWebKey:
        with open(keypath) as _sslkey:# pylint: disable=[unspecified-encoding]
            return JsonWebKey.import_key(_sslkey.read())

    key_storage_dir = Path(app.config["CLIENTS_SSL_PUBLIC_KEYS_DIR"])
    key_storage_dir.mkdir(exist_ok=True)
    app.config["SSL_PUBLIC_KEYS"] = {
        _key.as_dict()["kid"]: _key for _key in (
            __parse_key__(Path(key_storage_dir).joinpath(key))
            for key in os.listdir(key_storage_dir))}

    app.config["SSL_PRIVATE_KEY"] = __parse_key__(
        Path(app.config["SSL_PRIVATE_KEY"]))

def create_app(
        config: Optional[dict] = None,
        setup_logging: Callable[[Flask], None] = lambda appl: None
) -> Flask:
    """Create and return a new flask application."""
    app = Flask(__name__)

    # ====== Setup configuration ======
    app.config.from_object(settings) # Default settings
    # Override defaults with startup settings
    app.config.update(config or {})
    # Override app settings with site-local settings
    if "GN_AUTH_CONF" in os.environ:
        app.config.from_envvar("GN_AUTH_CONF")

    override_settings_with_envvars(app)

    load_secrets_conf(app)
    parse_ssl_keys(app)
    # ====== END: Setup configuration ======

    setup_logging(app)
    check_mandatory_settings(app)

    setup_oauth2_server(app)

    CORS(
        app,
        origins=app.config["CORS_ORIGINS"],
        allow_headers=app.config["CORS_HEADERS"],
        supports_credentials=True, intercept_exceptions=False)

    ## Blueprints
    app.register_blueprint(misc, url_prefix="/")
    app.register_blueprint(oauth2, url_prefix="/auth")

    register_error_handlers(app)

    return app