# push.py - webpush endpoints and tooling
import base64
import os
import json
from .versions import _DICT_VERSION_PUSH, _DICT_VERSION_PUSH_NOTIF
from .errors import MastodonIllegalArgumentError
from .utility import api_version
from .compat import IMPL_HAS_CRYPTO, ec, serialization, default_backend
from .compat import IMPL_HAS_ECE, http_ece
from .internals import Mastodon as Internals
class Mastodon(Internals):
###
# Reading data: Webpush subscriptions
###
@api_version("2.4.0", "2.4.0", _DICT_VERSION_PUSH)
def push_subscription(self):
"""
Fetch the current push subscription the logged-in user has for this app.
Returns a :ref:`push subscription dict <push subscription dict>`.
"""
return self.__api_request('GET', '/api/v1/push/subscription')
###
# Writing data: Push subscriptions
###
@api_version("2.4.0", "2.4.0", _DICT_VERSION_PUSH)
def push_subscription_set(self, endpoint, encrypt_params, follow_events=None,
favourite_events=None, reblog_events=None,
mention_events=None, poll_events=None,
follow_request_events=None, status_events=None, policy='all'):
"""
Sets up or modifies the push subscription the logged-in user has for this app.
`endpoint` is the endpoint URL mastodon should call for pushes. Note that mastodon
requires https for this URL. `encrypt_params` is a dict with key parameters that allow
the server to encrypt data for you: A public key `pubkey` and a shared secret `auth`.
You can generate this as well as the corresponding private key using the
:ref:`push_subscription_generate_keys() <push_subscription_generate_keys()>` function.
`policy` controls what sources will generate webpush events. Valid values are
`all`, `none`, `follower` and `followed`.
The rest of the parameters controls what kind of events you wish to subscribe to.
Returns a :ref:`push subscription dict <push subscription dict>`.
"""
if not policy in ['all', 'none', 'follower', 'followed']:
raise MastodonIllegalArgumentError("Valid values for policy are 'all', 'none', 'follower' or 'followed'.")
endpoint = Mastodon.__protocolize(endpoint)
push_pubkey_b64 = base64.b64encode(encrypt_params['pubkey'])
push_auth_b64 = base64.b64encode(encrypt_params['auth'])
params = {
'subscription[endpoint]': endpoint,
'subscription[keys][p256dh]': push_pubkey_b64,
'subscription[keys][auth]': push_auth_b64,
'policy': policy
}
if follow_events is not None:
params['data[alerts][follow]'] = follow_events
if favourite_events is not None:
params['data[alerts][favourite]'] = favourite_events
if reblog_events is not None:
params['data[alerts][reblog]'] = reblog_events
if mention_events is not None:
params['data[alerts][mention]'] = mention_events
if poll_events is not None:
params['data[alerts][poll]'] = poll_events
if follow_request_events is not None:
params['data[alerts][follow_request]'] = follow_request_events
if follow_request_events is not None:
params['data[alerts][status]'] = status_events
# Canonicalize booleans
params = self.__generate_params(params)
return self.__api_request('POST', '/api/v1/push/subscription', params)
@api_version("2.4.0", "2.4.0", _DICT_VERSION_PUSH)
def push_subscription_update(self, follow_events=None,
favourite_events=None, reblog_events=None,
mention_events=None, poll_events=None,
follow_request_events=None):
"""
Modifies what kind of events the app wishes to subscribe to.
Returns the updated :ref:`push subscription dict <push subscription dict>`.
"""
params = {}
if follow_events is not None:
params['data[alerts][follow]'] = follow_events
if favourite_events is not None:
params['data[alerts][favourite]'] = favourite_events
if reblog_events is not None:
params['data[alerts][reblog]'] = reblog_events
if mention_events is not None:
params['data[alerts][mention]'] = mention_events
if poll_events is not None:
params['data[alerts][poll]'] = poll_events
if follow_request_events is not None:
params['data[alerts][follow_request]'] = follow_request_events
# Canonicalize booleans
params = self.__generate_params(params)
return self.__api_request('PUT', '/api/v1/push/subscription', params)
@api_version("2.4.0", "2.4.0", "2.4.0")
def push_subscription_delete(self):
"""
Remove the current push subscription the logged-in user has for this app.
"""
self.__api_request('DELETE', '/api/v1/push/subscription')
###
# Push subscription crypto utilities
###
def push_subscription_generate_keys(self):
"""
Generates a private key, public key and shared secret for use in webpush subscriptions.
Returns two dicts: One with the private key and shared secret and another with the
public key and shared secret.
"""
if not IMPL_HAS_CRYPTO:
raise NotImplementedError(
'To use the crypto tools, please install the webpush feature dependencies.')
push_key_pair = ec.generate_private_key(ec.SECP256R1(), default_backend())
push_key_priv = push_key_pair.private_numbers().private_value
try:
push_key_pub = push_key_pair.public_key().public_bytes(
serialization.Encoding.X962,
serialization.PublicFormat.UncompressedPoint,
)
except:
push_key_pub = push_key_pair.public_key().public_numbers().encode_point()
push_shared_secret = os.urandom(16)
priv_dict = {
'privkey': push_key_priv,
'auth': push_shared_secret
}
pub_dict = {
'pubkey': push_key_pub,
'auth': push_shared_secret
}
return priv_dict, pub_dict
@api_version("2.4.0", "2.4.0", _DICT_VERSION_PUSH_NOTIF)
def push_subscription_decrypt_push(self, data, decrypt_params, encryption_header, crypto_key_header):
"""
Decrypts `data` received in a webpush request. Requires the private key dict
from :ref:`push_subscription_generate_keys() <push_subscription_generate_keys()>` (`decrypt_params`) as well as the
Encryption and server Crypto-Key headers from the received webpush
Returns the decoded webpush as a :ref:`push notification dict <push notification dict>`.
"""
if (not IMPL_HAS_ECE) or (not IMPL_HAS_CRYPTO):
raise NotImplementedError(
'To use the crypto tools, please install the webpush feature dependencies.')
salt = self.__decode_webpush_b64(encryption_header.split("salt=")[1].strip())
dhparams = self.__decode_webpush_b64(crypto_key_header.split("dh=")[1].split(";")[0].strip())
p256ecdsa = self.__decode_webpush_b64(crypto_key_header.split("p256ecdsa=")[1].strip())
dec_key = ec.derive_private_key(decrypt_params['privkey'], ec.SECP256R1(), default_backend())
decrypted = http_ece.decrypt(
data,
salt=salt,
key=p256ecdsa,
private_key=dec_key,
dh=dhparams,
auth_secret=decrypt_params['auth'],
keylabel="P-256",
version="aesgcm"
)
return json.loads(decrypted.decode('utf-8'), object_hook=Mastodon.__json_hooks)
