takahe/users/models/identity.py
2022-12-17 12:29:48 -07:00

612 lines
22 KiB
Python

from functools import cached_property, partial
from typing import Literal
from urllib.parse import urlparse
import httpx
import urlman
from asgiref.sync import async_to_sync, sync_to_async
from django.db import IntegrityError, models
from django.template.defaultfilters import linebreaks_filter
from django.utils import timezone
from django.utils.functional import lazy
from core.exceptions import ActorMismatchError
from core.html import sanitize_post, strip_html
from core.ld import canonicalise, format_ld_date, get_list, media_type_from_filename
from core.models import Config
from core.signatures import HttpSignature, RsaKeys
from core.uploads import upload_namer
from core.uris import AutoAbsoluteUrl, RelativeAbsoluteUrl, StaticAbsoluteUrl
from stator.models import State, StateField, StateGraph, StatorModel
from users.models.domain import Domain
from users.models.system_actor import SystemActor
class IdentityStates(StateGraph):
"""
There are only two states in a cycle.
Identities sit in "updated" for up to system.identity_max_age, and then
go back to "outdated" for refetching.
"""
outdated = State(try_interval=3600, force_initial=True)
updated = State(try_interval=86400 * 7, attempt_immediately=False)
outdated.transitions_to(updated)
updated.transitions_to(outdated)
@classmethod
async def handle_outdated(cls, identity: "Identity"):
# Local identities never need fetching
if identity.local:
return cls.updated
# Run the actor fetch and progress to updated if it succeeds
if await identity.fetch_actor():
return cls.updated
@classmethod
async def handle_updated(cls, instance: "Identity"):
if instance.state_age > Config.system.identity_max_age:
return cls.outdated
class Identity(StatorModel):
"""
Represents both local and remote Fediverse identities (actors)
"""
class Restriction(models.IntegerChoices):
none = 0
limited = 1
blocked = 2
# The Actor URI is essentially also a PK - we keep the default numeric
# one around as well for making nice URLs etc.
actor_uri = models.CharField(max_length=500, unique=True)
state = StateField(IdentityStates)
local = models.BooleanField()
users = models.ManyToManyField(
"users.User",
related_name="identities",
blank=True,
)
username = models.CharField(max_length=500, blank=True, null=True)
# Must be a display domain if present
domain = models.ForeignKey(
"users.Domain",
blank=True,
null=True,
on_delete=models.PROTECT,
related_name="identities",
)
name = models.CharField(max_length=500, blank=True, null=True)
summary = models.TextField(blank=True, null=True)
manually_approves_followers = models.BooleanField(blank=True, null=True)
discoverable = models.BooleanField(default=True)
profile_uri = models.CharField(max_length=500, blank=True, null=True)
inbox_uri = models.CharField(max_length=500, blank=True, null=True)
shared_inbox_uri = models.CharField(max_length=500, blank=True, null=True)
outbox_uri = models.CharField(max_length=500, blank=True, null=True)
icon_uri = models.CharField(max_length=500, blank=True, null=True)
image_uri = models.CharField(max_length=500, blank=True, null=True)
followers_uri = models.CharField(max_length=500, blank=True, null=True)
following_uri = models.CharField(max_length=500, blank=True, null=True)
icon = models.ImageField(
upload_to=partial(upload_namer, "profile_images"), blank=True, null=True
)
image = models.ImageField(
upload_to=partial(upload_namer, "background_images"), blank=True, null=True
)
# Should be a list of {"name":..., "value":...} dicts
metadata = models.JSONField(blank=True, null=True)
# Should be a list of object URIs (we don't want a full M2M here)
pinned = models.JSONField(blank=True, null=True)
# Admin-only moderation fields
sensitive = models.BooleanField(default=False)
restriction = models.IntegerField(
choices=Restriction.choices, default=Restriction.none
)
admin_notes = models.TextField(null=True, blank=True)
private_key = models.TextField(null=True, blank=True)
public_key = models.TextField(null=True, blank=True)
public_key_id = models.TextField(null=True, blank=True)
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
fetched = models.DateTimeField(null=True, blank=True)
deleted = models.DateTimeField(null=True, blank=True)
### Model attributes ###
class Meta:
verbose_name_plural = "identities"
unique_together = [("username", "domain")]
class urls(urlman.Urls):
view = "/@{self.username}@{self.domain_id}/"
action = "{view}action/"
activate = "{view}activate/"
admin = "/admin/identities/"
admin_edit = "{admin}{self.pk}/"
def get_scheme(self, url):
return "https"
def get_hostname(self, url):
return self.instance.domain.uri_domain
def __str__(self):
if self.username and self.domain_id:
return self.handle
return self.actor_uri
def absolute_profile_uri(self):
"""
Returns a profile URI that is always absolute, for sending out to
other servers.
"""
if self.local:
return f"https://{self.domain.uri_domain}/@{self.username}/"
else:
return self.profile_uri
def local_icon_url(self) -> RelativeAbsoluteUrl:
"""
Returns an icon for use by us, with fallbacks to a placeholder
"""
if self.icon:
return RelativeAbsoluteUrl(self.icon.url)
elif self.icon_uri:
return AutoAbsoluteUrl(f"/proxy/identity_icon/{self.pk}/")
else:
return StaticAbsoluteUrl("img/unknown-icon-128.png")
def local_image_url(self) -> RelativeAbsoluteUrl | None:
"""
Returns a background image for us, returning None if there isn't one
"""
if self.image:
return RelativeAbsoluteUrl(self.image.url)
elif self.image_uri:
return AutoAbsoluteUrl(f"/proxy/identity_image/{self.pk}/")
return None
@property
def safe_summary(self):
from activities.templatetags.emoji_tags import imageify_emojis
return imageify_emojis(sanitize_post(self.summary), self.domain)
@property
def safe_metadata(self):
from activities.templatetags.emoji_tags import imageify_emojis
if not self.metadata:
return []
return [
{
"name": data["name"],
"value": imageify_emojis(strip_html(data["value"]), self.domain),
}
for data in self.metadata
]
### Alternate constructors/fetchers ###
@classmethod
def by_username_and_domain(cls, username, domain, fetch=False, local=False):
if username.startswith("@"):
raise ValueError("Username must not start with @")
username = username.lower()
domain = domain.lower()
try:
if local:
return cls.objects.get(
username=username,
domain_id=domain,
local=True,
)
else:
return cls.objects.get(
username=username,
domain_id=domain,
)
except cls.DoesNotExist:
if fetch and not local:
actor_uri, handle = async_to_sync(cls.fetch_webfinger)(
f"{username}@{domain}"
)
if handle is None:
return None
# See if this actually does match an existing actor
try:
return cls.objects.get(actor_uri=actor_uri)
except cls.DoesNotExist:
pass
# OK, make one
username, domain = handle.split("@")
domain = Domain.get_remote_domain(domain)
return cls.objects.create(
actor_uri=actor_uri,
username=username,
domain_id=domain,
local=False,
)
return None
@classmethod
def by_actor_uri(cls, uri, create=False, transient=False) -> "Identity":
try:
return cls.objects.get(actor_uri=uri)
except cls.DoesNotExist:
if create:
if transient:
# Some code (like inbox fetching) doesn't need this saved
# to the DB until the fetch succeeds
return cls(actor_uri=uri, local=False)
else:
return cls.objects.create(actor_uri=uri, local=False)
else:
raise cls.DoesNotExist(f"No identity found with actor_uri {uri}")
### Dynamic properties ###
@property
def name_or_handle(self):
return self.name or self.handle
@cached_property
def html_name_or_handle(self):
"""
Return the name_or_handle with any HTML substitutions made
"""
from activities.templatetags.emoji_tags import imageify_emojis
return imageify_emojis(self.name_or_handle, self.domain)
@property
def handle(self):
if self.username is None:
return "(unknown user)"
if self.domain_id:
return f"{self.username}@{self.domain_id}"
return f"{self.username}@(unknown server)"
@property
def data_age(self) -> float:
"""
How old our copy of this data is, in seconds
"""
if self.local:
return 0
if self.fetched is None:
return 10000000000
return (timezone.now() - self.fetched).total_seconds()
@property
def outdated(self) -> bool:
# TODO: Setting
return self.data_age > 60 * 24 * 24
@property
def blocked(self) -> bool:
return self.restriction == self.Restriction.blocked
@property
def limited(self) -> bool:
return self.restriction == self.Restriction.limited
### ActivityPub (outbound) ###
def to_ap(self):
response = {
"id": self.actor_uri,
"type": "Person",
"inbox": self.actor_uri + "inbox/",
"preferredUsername": self.username,
"publicKey": {
"id": self.public_key_id,
"owner": self.actor_uri,
"publicKeyPem": self.public_key,
},
"published": self.created.strftime("%Y-%m-%dT%H:%M:%SZ"),
"url": self.absolute_profile_uri(),
"toot:discoverable": self.discoverable,
}
if self.name:
response["name"] = self.name
if self.summary:
response["summary"] = str(linebreaks_filter(self.summary))
if self.icon:
response["icon"] = {
"type": "Image",
"mediaType": media_type_from_filename(self.icon.name),
"url": self.icon.url,
}
if self.image:
response["image"] = {
"type": "Image",
"mediaType": media_type_from_filename(self.image.name),
"url": self.image.url,
}
if self.local:
response["endpoints"] = {
"sharedInbox": f"https://{self.domain.uri_domain}/inbox/",
}
return response
def to_ap_tag(self):
"""
Return this Identity as an ActivityPub Tag
"""
return {
"href": self.actor_uri,
"name": "@" + self.handle,
"type": "Mention",
}
### ActivityPub (inbound) ###
@classmethod
def handle_update_ap(cls, data):
"""
Takes an incoming update.person message and just forces us to add it
to our fetch queue (don't want to bother with two load paths right now)
"""
# Find by actor
try:
actor = cls.by_actor_uri(data["actor"])
actor.transition_perform(IdentityStates.outdated)
except cls.DoesNotExist:
pass
@classmethod
def handle_delete_ap(cls, data):
"""
Takes an incoming update.person message and just forces us to add it
to our fetch queue (don't want to bother with two load paths right now)
"""
# Assert that the actor matches the object
if data["actor"] != data["object"]:
raise ActorMismatchError(
f"Actor {data['actor']} trying to delete identity {data['object']}"
)
# Find by actor
try:
actor = cls.by_actor_uri(data["actor"])
actor.delete()
except cls.DoesNotExist:
pass
### Actor/Webfinger fetching ###
@classmethod
async def fetch_webfinger(cls, handle: str) -> tuple[str | None, str | None]:
"""
Given a username@domain handle, returns a tuple of
(actor uri, canonical handle) or None, None if it does not resolve.
"""
domain = handle.split("@")[1].lower()
try:
async with httpx.AsyncClient() as client:
response = await client.get(
f"https://{domain}/.well-known/webfinger?resource=acct:{handle}",
)
except httpx.RequestError:
return None, None
if response.status_code in [404, 410]:
return None, None
if response.status_code >= 500:
return None, None
if response.status_code >= 400:
raise ValueError(
f"Client error fetching webfinger: {response.status_code}",
response.content,
)
data = response.json()
if data["subject"].startswith("acct:"):
data["subject"] = data["subject"][5:]
for link in data["links"]:
if (
link.get("type") == "application/activity+json"
and link.get("rel") == "self"
):
return link["href"], data["subject"]
return None, None
async def fetch_actor(self) -> bool:
"""
Fetches the user's actor information, as well as their domain from
webfinger if it's available.
"""
from activities.models import Emoji
if self.local:
raise ValueError("Cannot fetch local identities")
try:
response = await SystemActor().signed_request(
method="get",
uri=self.actor_uri,
)
except httpx.RequestError:
return False
if response.status_code == 410:
# Their account got deleted, so let's do the same.
if self.pk:
await Identity.objects.filter(pk=self.pk).adelete()
return False
if response.status_code == 404:
# We don't trust this as much as 410 Gone, but skip for now
return False
if response.status_code >= 500:
return False
if response.status_code >= 400:
raise ValueError(
f"Client error fetching actor: {response.status_code}", response.content
)
document = canonicalise(response.json(), include_security=True)
self.name = document.get("name")
self.profile_uri = document.get("url")
self.inbox_uri = document.get("inbox")
self.outbox_uri = document.get("outbox")
self.followers_uri = document.get("followers")
self.following_uri = document.get("following")
self.shared_inbox_uri = document.get("endpoints", {}).get("sharedInbox")
self.summary = document.get("summary")
self.username = document.get("preferredUsername")
if self.username and "@value" in self.username:
self.username = self.username["@value"]
if self.username:
self.username = self.username.lower()
self.manually_approves_followers = document.get("manuallyApprovesFollowers")
self.public_key = document.get("publicKey", {}).get("publicKeyPem")
self.public_key_id = document.get("publicKey", {}).get("id")
self.icon_uri = document.get("icon", {}).get("url")
self.image_uri = document.get("image", {}).get("url")
self.discoverable = document.get("toot:discoverable", True)
# Profile links/metadata
self.metadata = []
for attachment in get_list(document, "attachment"):
if (
attachment["type"] == "http://schema.org#PropertyValue"
and "name" in attachment
and "http://schema.org#value" in attachment
):
self.metadata.append(
{
"name": attachment.get("name"),
"value": strip_html(attachment.get("http://schema.org#value")),
}
)
# Now go do webfinger with that info to see if we can get a canonical domain
actor_url_parts = urlparse(self.actor_uri)
get_domain = sync_to_async(Domain.get_remote_domain)
if self.username:
webfinger_actor, webfinger_handle = await self.fetch_webfinger(
f"{self.username}@{actor_url_parts.hostname}"
)
if webfinger_handle:
webfinger_username, webfinger_domain = webfinger_handle.split("@")
self.username = webfinger_username.lower()
self.domain = await get_domain(webfinger_domain)
else:
self.domain = await get_domain(actor_url_parts.hostname)
else:
self.domain = await get_domain(actor_url_parts.hostname)
# Emojis (we need the domain so we do them here)
for tag in get_list(document, "tag"):
if tag["type"].lower() == "toot:emoji":
await sync_to_async(Emoji.by_ap_tag)(self.domain, tag, create=True)
# Mark as fetched
self.fetched = timezone.now()
try:
await sync_to_async(self.save)()
except IntegrityError as e:
# See if we can fetch a PK and save there
if self.pk is None:
try:
other_row = await Identity.objects.aget(actor_uri=self.actor_uri)
except Identity.DoesNotExist:
raise ValueError(
f"Could not save Identity at end of actor fetch: {e}"
)
self.pk: int | None = other_row.pk
await sync_to_async(self.save)()
return True
### Mastodon Client API ###
def to_mastodon_json(self):
from activities.models import Emoji
header_image = self.local_image_url()
metadata_value_text = (
" ".join([m["value"] for m in self.metadata]) if self.metadata else ""
)
emojis = Emoji.emojis_from_content(
f"{self.name} {self.summary} {metadata_value_text}", self.domain
)
return {
"id": self.pk,
"username": self.username or "",
"acct": self.username if self.local else self.handle,
"url": self.absolute_profile_uri() or "",
"display_name": self.name or "",
"note": self.summary or "",
"avatar": self.local_icon_url().absolute,
"avatar_static": self.local_icon_url().absolute,
"header": header_image.absolute if header_image else None,
"header_static": header_image.absolute if header_image else None,
"locked": False,
"fields": (
[
{"name": m["name"], "value": m["value"], "verified_at": None}
for m in self.metadata
]
if self.metadata
else []
),
"emojis": [emoji.to_mastodon_json() for emoji in emojis],
"bot": False,
"group": False,
"discoverable": self.discoverable,
"suspended": False,
"limited": False,
"created_at": format_ld_date(
self.created.replace(hour=0, minute=0, second=0, microsecond=0)
),
"last_status_at": None, # TODO: populate
"statuses_count": self.posts.count(),
"followers_count": self.inbound_follows.count(),
"following_count": self.outbound_follows.count(),
}
### Cryptography ###
async def signed_request(
self,
method: Literal["get", "post"],
uri: str,
body: dict | None = None,
):
"""
Performs a signed request on behalf of the System Actor.
"""
return await HttpSignature.signed_request(
method=method,
uri=uri,
body=body,
private_key=self.private_key,
key_id=self.public_key_id,
)
def generate_keypair(self):
if not self.local:
raise ValueError("Cannot generate keypair for remote user")
self.private_key, self.public_key = RsaKeys.generate_keypair()
self.public_key_id = self.actor_uri + "#main-key"
self.save()
### Config ###
@cached_property
def config_identity(self) -> Config.IdentityOptions:
return Config.load_identity(self)
def lazy_config_value(self, key: str):
"""
Lazily load a config value for this Identity
"""
if key not in Config.IdentityOptions.__fields__:
raise KeyError(f"Undefined IdentityOption for {key}")
return lazy(lambda: getattr(self.config_identity, key))