Files
dragonion-core/dragonion_core/proto/web/webmessage.py
2023-07-17 15:41:15 +03:00

158 lines
4.1 KiB
Python

from typing import Literal, Final, Union
from dataclasses_json import dataclass_json
from dataclasses import dataclass, field
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives import hashes
import base64
from ..encryption.identity import Identity
webmessage_type_literal = Literal[
"connect", "message", "disconnect", "error", "notification"
]
webmessage_error_message_literal = Literal[
"unknown", "username_exists", "invalid_webmessage"
]
@dataclass_json
@dataclass
class _WebAnyMessage:
username: str | None = None
type: webmessage_type_literal = "message"
message: str | None = None
error_message: webmessage_error_message_literal | None = None
@dataclass_json
@dataclass
class WebMessageMessage:
"""
Sent as regular message
:param username: From user
:param message: Encrypted b64-encoded message
"""
username: str
message: bytes
type: Final = "message"
def decrypt(self, identity: Identity):
return identity.decrypt(self.message)
@dataclass_json
@dataclass
class WebErrorMessage:
"""
Sent when error on server occurs
:param error_message: See webmessage_error_message_literal
"""
error_message: webmessage_error_message_literal
type: Final = "error"
@dataclass_json
@dataclass
class WebConnectionMessage:
"""
Sent when user is connected (sent by user)
:param username: Username of connected
:param public_key: b64-encoded rsa public key
"""
username: str
public_key: bytes
type = "connect"
@dataclass_json
@dataclass
class WebDisconnectMessage:
"""
Sent when user is disconnected
:param username: Username of disconnected
"""
username: str
type = "disconnect"
@dataclass_json
@dataclass
class WebNotificationMessage:
"""
Sent from server name as unencrypted notification
:param message: Message content, not encrypted
"""
message: str
type: Final = "notification"
webmessages_union = Union[
WebMessageMessage,
WebErrorMessage,
WebConnectionMessage,
WebDisconnectMessage,
WebNotificationMessage
]
class WebMessage:
"""
Class for handling incoming webmessages
"""
@staticmethod
def from_json(data) -> webmessages_union:
"""
Restores webmessage object from json
:param data: Valid json data
:return: One of types from webmessages_union
"""
return {
"connect": WebConnectionMessage.from_json,
"disconnect": WebDisconnectMessage.from_json,
"message": WebMessageMessage.from_json,
"error": WebErrorMessage.from_json,
"notification": WebNotificationMessage.from_json
}[_WebAnyMessage.from_json(data).type](data)
@dataclass
class WebBroadcastableMessage:
"""
Class for creating outcoming messages
:param from_user: User, that send message
:param message_content: Text of message
:param keys: Dict with public keys in format username:public_key
"""
from_user: str
message_content: str
keys: dict[str, bytes]
encrypted_messages: dict[str, webmessages_union] = field(default_factory=dict)
def __post_init__(self):
for username in self.keys.keys():
public_key = serialization.load_der_public_key(
base64.urlsafe_b64decode(self.keys[username])
)
self.encrypted_messages[username] = WebMessageMessage(
username=self.from_user,
message=base64.urlsafe_b64encode(public_key.encrypt(
self.message_content.encode(),
padding=padding.OAEP(
mgf=padding.MGF1(algorithm=hashes.SHA256()),
algorithm=hashes.SHA256(),
label=None
)
))
)
def json(self):
return dict(
map(
lambda i, j: (i, j),
self.encrypted_messages.keys(),
[item.to_json() for item in self.encrypted_messages.values()]
)
)