4.21.3

2022-12-30 16:23:27 +00:00
parent 02776e8478
commit 20da343c54
1304 changed files with 870224 additions and 0 deletions
--- a/app/app/handler/unsubscribe_encoder.py
+++ b/app/app/handler/unsubscribe_encoder.py
@ -0,0 +1,149 @@
+import base64
+import enum
+import hashlib
+import json
+from dataclasses import dataclass
+from typing import Optional, Union
+
+import itsdangerous
+
+from app import config
+from app.log import LOG
+
+UNSUB_PREFIX = "un"
+
+
+class UnsubscribeAction(enum.Enum):
+    UnsubscribeNewsletter = 1
+    DisableAlias = 2
+    DisableContact = 3
+    OriginalUnsubscribeMailto = 4
+
+
+@dataclass
+class UnsubscribeOriginalData:
+    alias_id: int
+    recipient: str
+    subject: str
+
+
+@dataclass
+class UnsubscribeData:
+    action: UnsubscribeAction
+    data: Union[UnsubscribeOriginalData, int]
+
+
+@dataclass
+class UnsubscribeLink:
+    link: str
+    via_email: bool
+
+
+class UnsubscribeEncoder:
+    @staticmethod
+    def encode(
+        action: UnsubscribeAction, data: Union[int, UnsubscribeOriginalData]
+    ) -> UnsubscribeLink:
+        if config.UNSUBSCRIBER:
+            return UnsubscribeLink(UnsubscribeEncoder.encode_mailto(action, data), True)
+        return UnsubscribeLink(UnsubscribeEncoder.encode_url(action, data), False)
+
+    @classmethod
+    def encode_subject(
+        cls, action: UnsubscribeAction, data: Union[int, UnsubscribeOriginalData]
+    ) -> str:
+        if (
+            action != UnsubscribeAction.OriginalUnsubscribeMailto
+            and type(data) is not int
+        ):
+            raise ValueError(f"Data has to be an int for an action of type {action}")
+        if action == UnsubscribeAction.OriginalUnsubscribeMailto:
+            if type(data) is not UnsubscribeOriginalData:
+                raise ValueError(
+                    f"Data has to be an UnsubscribeOriginalData for an action of type {action}"
+                )
+            # Initial 0 is the version number. If we need to add support for extra use-cases we can bump up this number
+            data = (0, data.alias_id, data.recipient, data.subject)
+        payload = (action.value, data)
+        serialized_data = (
+            base64.urlsafe_b64encode(json.dumps(payload).encode("utf-8"))
+            .rstrip(b"=")
+            .decode("utf-8")
+        )
+        signed_data = cls._get_signer().sign(serialized_data).decode("utf-8")
+        encoded_request = f"{UNSUB_PREFIX}.{signed_data}"
+        if len(encoded_request) > 256:
+            LOG.e("Encoded request is longer than 256 chars")
+        return encoded_request
+
+    @staticmethod
+    def encode_mailto(
+        action: UnsubscribeAction, data: Union[int, UnsubscribeOriginalData]
+    ) -> str:
+        subject = UnsubscribeEncoder.encode_subject(action, data)
+        return f"mailto:{config.UNSUBSCRIBER}?subject={subject}"
+
+    @staticmethod
+    def encode_url(
+        action: UnsubscribeAction, data: Union[int, UnsubscribeOriginalData]
+    ) -> str:
+        if action == UnsubscribeAction.DisableAlias:
+            return f"{config.URL}/dashboard/unsubscribe/{data}"
+        if action == UnsubscribeAction.DisableContact:
+            return f"{config.URL}/dashboard/block_contact/{data}"
+        if action in (
+            UnsubscribeAction.UnsubscribeNewsletter,
+            UnsubscribeAction.OriginalUnsubscribeMailto,
+        ):
+            encoded = UnsubscribeEncoder.encode_subject(action, data)
+            return f"{config.URL}/dashboard/unsubscribe/encoded?data={encoded}"
+
+    @staticmethod
+    def _get_signer() -> itsdangerous.Signer:
+        return itsdangerous.Signer(
+            config.UNSUBSCRIBE_SECRET, digest_method=hashlib.sha3_224
+        )
+
+    @classmethod
+    def decode_subject(cls, data: str) -> Optional[UnsubscribeData]:
+        if data.find(UNSUB_PREFIX) == -1:
+            try:
+                # subject has the format {alias.id}=
+                if data.endswith("="):
+                    alias_id = int(data[:-1])
+                    return UnsubscribeData(UnsubscribeAction.DisableAlias, alias_id)
+                # {contact.id}_
+                elif data.endswith("_"):
+                    contact_id = int(data[:-1])
+                    return UnsubscribeData(UnsubscribeAction.DisableContact, contact_id)
+                # {user.id}*
+                elif data.endswith("*"):
+                    user_id = int(data[:-1])
+                    return UnsubscribeData(
+                        UnsubscribeAction.UnsubscribeNewsletter, user_id
+                    )
+                else:
+                    # some email providers might strip off the = suffix
+                    alias_id = int(data)
+                    return UnsubscribeData(UnsubscribeAction.DisableAlias, alias_id)
+            except ValueError:
+                return None
+
+        signer = cls._get_signer()
+        try:
+            verified_data = signer.unsign(data[len(UNSUB_PREFIX) + 1 :])
+        except itsdangerous.BadSignature:
+            return None
+        try:
+            padded_data = verified_data + (b"=" * (-len(verified_data) % 4))
+            payload = json.loads(base64.urlsafe_b64decode(padded_data))
+        except ValueError:
+            return None
+        action = UnsubscribeAction(payload[0])
+        action_data = payload[1]
+        if action == UnsubscribeAction.OriginalUnsubscribeMailto:
+            # Skip version number in action_data[0] for now it's always 0
+            action_data = UnsubscribeOriginalData(
+                action_data[1], action_data[2], action_data[3]
+            )
+        return UnsubscribeData(action, action_data)