Flatten the synapse.rest.client package (#10600)

1 files changed, 910 insertions, 0 deletions

diff --git a/synapse/rest/client/account.py b/synapse/rest/client/account.py
new file mode 100644
index 0000000000..fb5ad2906e
--- /dev/null
+++ b/synapse/rest/client/account.py
@@ -0,0 +1,910 @@
+# Copyright 2015, 2016 OpenMarket Ltd
+# Copyright 2017 Vector Creations Ltd
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+import random
+from http import HTTPStatus
+from typing import TYPE_CHECKING
+from urllib.parse import urlparse
+
+from synapse.api.constants import LoginType
+from synapse.api.errors import (
+    Codes,
+    InteractiveAuthIncompleteError,
+    SynapseError,
+    ThreepidValidationError,
+)
+from synapse.config.emailconfig import ThreepidBehaviour
+from synapse.handlers.ui_auth import UIAuthSessionDataConstants
+from synapse.http.server import finish_request, respond_with_html
+from synapse.http.servlet import (
+    RestServlet,
+    assert_params_in_dict,
+    parse_json_object_from_request,
+    parse_string,
+)
+from synapse.metrics import threepid_send_requests
+from synapse.push.mailer import Mailer
+from synapse.util.msisdn import phone_number_to_msisdn
+from synapse.util.stringutils import assert_valid_client_secret, random_string
+from synapse.util.threepids import check_3pid_allowed, validate_email
+
+from ._base import client_patterns, interactive_auth_handler
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+
+logger = logging.getLogger(__name__)
+
+
+class EmailPasswordRequestTokenRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/password/email/requestToken$")
+
+    def __init__(self, hs: "HomeServer"):
+        super().__init__()
+        self.hs = hs
+        self.datastore = hs.get_datastore()
+        self.config = hs.config
+        self.identity_handler = hs.get_identity_handler()
+
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+            self.mailer = Mailer(
+                hs=self.hs,
+                app_name=self.config.email_app_name,
+                template_html=self.config.email_password_reset_template_html,
+                template_text=self.config.email_password_reset_template_text,
+            )
+
+    async def on_POST(self, request):
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.local_threepid_handling_disabled_due_to_email_config:
+                logger.warning(
+                    "User password resets have been disabled due to lack of email config"
+                )
+            raise SynapseError(
+                400, "Email-based password resets have been disabled on this server"
+            )
+
+        body = parse_json_object_from_request(request)
+
+        assert_params_in_dict(body, ["client_secret", "email", "send_attempt"])
+
+        # Extract params from body
+        client_secret = body["client_secret"]
+        assert_valid_client_secret(client_secret)
+
+        # Canonicalise the email address. The addresses are all stored canonicalised
+        # in the database. This allows the user to reset his password without having to
+        # know the exact spelling (eg. upper and lower case) of address in the database.
+        # Stored in the database "foo@bar.com"
+        # User requests with "FOO@bar.com" would raise a Not Found error
+        try:
+            email = validate_email(body["email"])
+        except ValueError as e:
+            raise SynapseError(400, str(e))
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
+
+        if next_link:
+            # Raise if the provided next_link value isn't valid
+            assert_valid_next_link(self.hs, next_link)
+
+        await self.identity_handler.ratelimit_request_token_requests(
+            request, "email", email
+        )
+
+        # The email will be sent to the stored address.
+        # This avoids a potential account hijack by requesting a password reset to
+        # an email address which is controlled by the attacker but which, after
+        # canonicalisation, matches the one in our database.
+        existing_user_id = await self.hs.get_datastore().get_user_id_by_threepid(
+            "email", email
+        )
+
+        if existing_user_id is None:
+            if self.config.request_token_inhibit_3pid_errors:
+                # Make the client think the operation succeeded. See the rationale in the
+                # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
+                return 200, {"sid": random_string(16)}
+
+            raise SynapseError(400, "Email not found", Codes.THREEPID_NOT_FOUND)
+
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            assert self.hs.config.account_threepid_delegate_email
+
+            # Have the configured identity server handle the request
+            ret = await self.identity_handler.requestEmailToken(
+                self.hs.config.account_threepid_delegate_email,
+                email,
+                client_secret,
+                send_attempt,
+                next_link,
+            )
+        else:
+            # Send password reset emails from Synapse
+            sid = await self.identity_handler.send_threepid_validation(
+                email,
+                client_secret,
+                send_attempt,
+                self.mailer.send_password_reset_mail,
+                next_link,
+            )
+
+            # Wrap the session id in a JSON object
+            ret = {"sid": sid}
+
+        threepid_send_requests.labels(type="email", reason="password_reset").observe(
+            send_attempt
+        )
+
+        return 200, ret
+
+
+class PasswordRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/password$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.auth = hs.get_auth()
+        self.auth_handler = hs.get_auth_handler()
+        self.datastore = self.hs.get_datastore()
+        self.password_policy_handler = hs.get_password_policy_handler()
+        self._set_password_handler = hs.get_set_password_handler()
+
+    @interactive_auth_handler
+    async def on_POST(self, request):
+        body = parse_json_object_from_request(request)
+
+        # we do basic sanity checks here because the auth layer will store these
+        # in sessions. Pull out the new password provided to us.
+        new_password = body.pop("new_password", None)
+        if new_password is not None:
+            if not isinstance(new_password, str) or len(new_password) > 512:
+                raise SynapseError(400, "Invalid password")
+            self.password_policy_handler.validate_password(new_password)
+
+        # there are two possibilities here. Either the user does not have an
+        # access token, and needs to do a password reset; or they have one and
+        # need to validate their identity.
+        #
+        # In the first case, we offer a couple of means of identifying
+        # themselves (email and msisdn, though it's unclear if msisdn actually
+        # works).
+        #
+        # In the second case, we require a password to confirm their identity.
+
+        if self.auth.has_access_token(request):
+            requester = await self.auth.get_user_by_req(request)
+            try:
+                params, session_id = await self.auth_handler.validate_user_via_ui_auth(
+                    requester,
+                    request,
+                    body,
+                    "modify your account password",
+                )
+            except InteractiveAuthIncompleteError as e:
+                # The user needs to provide more steps to complete auth, but
+                # they're not required to provide the password again.
+                #
+                # If a password is available now, hash the provided password and
+                # store it for later.
+                if new_password:
+                    password_hash = await self.auth_handler.hash(new_password)
+                    await self.auth_handler.set_session_data(
+                        e.session_id,
+                        UIAuthSessionDataConstants.PASSWORD_HASH,
+                        password_hash,
+                    )
+                raise
+            user_id = requester.user.to_string()
+        else:
+            requester = None
+            try:
+                result, params, session_id = await self.auth_handler.check_ui_auth(
+                    [[LoginType.EMAIL_IDENTITY]],
+                    request,
+                    body,
+                    "modify your account password",
+                )
+            except InteractiveAuthIncompleteError as e:
+                # The user needs to provide more steps to complete auth, but
+                # they're not required to provide the password again.
+                #
+                # If a password is available now, hash the provided password and
+                # store it for later.
+                if new_password:
+                    password_hash = await self.auth_handler.hash(new_password)
+                    await self.auth_handler.set_session_data(
+                        e.session_id,
+                        UIAuthSessionDataConstants.PASSWORD_HASH,
+                        password_hash,
+                    )
+                raise
+
+            if LoginType.EMAIL_IDENTITY in result:
+                threepid = result[LoginType.EMAIL_IDENTITY]
+                if "medium" not in threepid or "address" not in threepid:
+                    raise SynapseError(500, "Malformed threepid")
+                if threepid["medium"] == "email":
+                    # For emails, canonicalise the address.
+                    # We store all email addresses canonicalised in the DB.
+                    # (See add_threepid in synapse/handlers/auth.py)
+                    try:
+                        threepid["address"] = validate_email(threepid["address"])
+                    except ValueError as e:
+                        raise SynapseError(400, str(e))
+                # if using email, we must know about the email they're authing with!
+                threepid_user_id = await self.datastore.get_user_id_by_threepid(
+                    threepid["medium"], threepid["address"]
+                )
+                if not threepid_user_id:
+                    raise SynapseError(404, "Email address not found", Codes.NOT_FOUND)
+                user_id = threepid_user_id
+            else:
+                logger.error("Auth succeeded but no known type! %r", result.keys())
+                raise SynapseError(500, "", Codes.UNKNOWN)
+
+        # If we have a password in this request, prefer it. Otherwise, use the
+        # password hash from an earlier request.
+        if new_password:
+            password_hash = await self.auth_handler.hash(new_password)
+        elif session_id is not None:
+            password_hash = await self.auth_handler.get_session_data(
+                session_id, UIAuthSessionDataConstants.PASSWORD_HASH, None
+            )
+        else:
+            # UI validation was skipped, but the request did not include a new
+            # password.
+            password_hash = None
+        if not password_hash:
+            raise SynapseError(400, "Missing params: password", Codes.MISSING_PARAM)
+
+        logout_devices = params.get("logout_devices", True)
+
+        await self._set_password_handler.set_password(
+            user_id, password_hash, logout_devices, requester
+        )
+
+        return 200, {}
+
+
+class DeactivateAccountRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/deactivate$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.auth = hs.get_auth()
+        self.auth_handler = hs.get_auth_handler()
+        self._deactivate_account_handler = hs.get_deactivate_account_handler()
+
+    @interactive_auth_handler
+    async def on_POST(self, request):
+        body = parse_json_object_from_request(request)
+        erase = body.get("erase", False)
+        if not isinstance(erase, bool):
+            raise SynapseError(
+                HTTPStatus.BAD_REQUEST,
+                "Param 'erase' must be a boolean, if given",
+                Codes.BAD_JSON,
+            )
+
+        requester = await self.auth.get_user_by_req(request)
+
+        # allow ASes to deactivate their own users
+        if requester.app_service:
+            await self._deactivate_account_handler.deactivate_account(
+                requester.user.to_string(), erase, requester
+            )
+            return 200, {}
+
+        await self.auth_handler.validate_user_via_ui_auth(
+            requester,
+            request,
+            body,
+            "deactivate your account",
+        )
+        result = await self._deactivate_account_handler.deactivate_account(
+            requester.user.to_string(),
+            erase,
+            requester,
+            id_server=body.get("id_server"),
+        )
+        if result:
+            id_server_unbind_result = "success"
+        else:
+            id_server_unbind_result = "no-support"
+
+        return 200, {"id_server_unbind_result": id_server_unbind_result}
+
+
+class EmailThreepidRequestTokenRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid/email/requestToken$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.config = hs.config
+        self.identity_handler = hs.get_identity_handler()
+        self.store = self.hs.get_datastore()
+
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+            self.mailer = Mailer(
+                hs=self.hs,
+                app_name=self.config.email_app_name,
+                template_html=self.config.email_add_threepid_template_html,
+                template_text=self.config.email_add_threepid_template_text,
+            )
+
+    async def on_POST(self, request):
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.local_threepid_handling_disabled_due_to_email_config:
+                logger.warning(
+                    "Adding emails have been disabled due to lack of an email config"
+                )
+            raise SynapseError(
+                400, "Adding an email to your account is disabled on this server"
+            )
+
+        body = parse_json_object_from_request(request)
+        assert_params_in_dict(body, ["client_secret", "email", "send_attempt"])
+        client_secret = body["client_secret"]
+        assert_valid_client_secret(client_secret)
+
+        # Canonicalise the email address. The addresses are all stored canonicalised
+        # in the database.
+        # This ensures that the validation email is sent to the canonicalised address
+        # as it will later be entered into the database.
+        # Otherwise the email will be sent to "FOO@bar.com" and stored as
+        # "foo@bar.com" in database.
+        try:
+            email = validate_email(body["email"])
+        except ValueError as e:
+            raise SynapseError(400, str(e))
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
+
+        if not check_3pid_allowed(self.hs, "email", email):
+            raise SynapseError(
+                403,
+                "Your email domain is not authorized on this server",
+                Codes.THREEPID_DENIED,
+            )
+
+        await self.identity_handler.ratelimit_request_token_requests(
+            request, "email", email
+        )
+
+        if next_link:
+            # Raise if the provided next_link value isn't valid
+            assert_valid_next_link(self.hs, next_link)
+
+        existing_user_id = await self.store.get_user_id_by_threepid("email", email)
+
+        if existing_user_id is not None:
+            if self.config.request_token_inhibit_3pid_errors:
+                # Make the client think the operation succeeded. See the rationale in the
+                # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
+                return 200, {"sid": random_string(16)}
+
+            raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
+
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            assert self.hs.config.account_threepid_delegate_email
+
+            # Have the configured identity server handle the request
+            ret = await self.identity_handler.requestEmailToken(
+                self.hs.config.account_threepid_delegate_email,
+                email,
+                client_secret,
+                send_attempt,
+                next_link,
+            )
+        else:
+            # Send threepid validation emails from Synapse
+            sid = await self.identity_handler.send_threepid_validation(
+                email,
+                client_secret,
+                send_attempt,
+                self.mailer.send_add_threepid_mail,
+                next_link,
+            )
+
+            # Wrap the session id in a JSON object
+            ret = {"sid": sid}
+
+        threepid_send_requests.labels(type="email", reason="add_threepid").observe(
+            send_attempt
+        )
+
+        return 200, ret
+
+
+class MsisdnThreepidRequestTokenRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid/msisdn/requestToken$")
+
+    def __init__(self, hs: "HomeServer"):
+        self.hs = hs
+        super().__init__()
+        self.store = self.hs.get_datastore()
+        self.identity_handler = hs.get_identity_handler()
+
+    async def on_POST(self, request):
+        body = parse_json_object_from_request(request)
+        assert_params_in_dict(
+            body, ["client_secret", "country", "phone_number", "send_attempt"]
+        )
+        client_secret = body["client_secret"]
+        assert_valid_client_secret(client_secret)
+
+        country = body["country"]
+        phone_number = body["phone_number"]
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
+
+        msisdn = phone_number_to_msisdn(country, phone_number)
+
+        if not check_3pid_allowed(self.hs, "msisdn", msisdn):
+            raise SynapseError(
+                403,
+                "Account phone numbers are not authorized on this server",
+                Codes.THREEPID_DENIED,
+            )
+
+        await self.identity_handler.ratelimit_request_token_requests(
+            request, "msisdn", msisdn
+        )
+
+        if next_link:
+            # Raise if the provided next_link value isn't valid
+            assert_valid_next_link(self.hs, next_link)
+
+        existing_user_id = await self.store.get_user_id_by_threepid("msisdn", msisdn)
+
+        if existing_user_id is not None:
+            if self.hs.config.request_token_inhibit_3pid_errors:
+                # Make the client think the operation succeeded. See the rationale in the
+                # comments for request_token_inhibit_3pid_errors.
+                # Also wait for some random amount of time between 100ms and 1s to make it
+                # look like we did something.
+                await self.hs.get_clock().sleep(random.randint(1, 10) / 10)
+                return 200, {"sid": random_string(16)}
+
+            raise SynapseError(400, "MSISDN is already in use", Codes.THREEPID_IN_USE)
+
+        if not self.hs.config.account_threepid_delegate_msisdn:
+            logger.warning(
+                "No upstream msisdn account_threepid_delegate configured on the server to "
+                "handle this request"
+            )
+            raise SynapseError(
+                400,
+                "Adding phone numbers to user account is not supported by this homeserver",
+            )
+
+        ret = await self.identity_handler.requestMsisdnToken(
+            self.hs.config.account_threepid_delegate_msisdn,
+            country,
+            phone_number,
+            client_secret,
+            send_attempt,
+            next_link,
+        )
+
+        threepid_send_requests.labels(type="msisdn", reason="add_threepid").observe(
+            send_attempt
+        )
+
+        return 200, ret
+
+
+class AddThreepidEmailSubmitTokenServlet(RestServlet):
+    """Handles 3PID validation token submission for adding an email to a user's account"""
+
+    PATTERNS = client_patterns(
+        "/add_threepid/email/submit_token$", releases=(), unstable=True
+    )
+
+    def __init__(self, hs):
+        """
+        Args:
+            hs (synapse.server.HomeServer): server
+        """
+        super().__init__()
+        self.config = hs.config
+        self.clock = hs.get_clock()
+        self.store = hs.get_datastore()
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+            self._failure_email_template = (
+                self.config.email_add_threepid_template_failure_html
+            )
+
+    async def on_GET(self, request):
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.local_threepid_handling_disabled_due_to_email_config:
+                logger.warning(
+                    "Adding emails have been disabled due to lack of an email config"
+                )
+            raise SynapseError(
+                400, "Adding an email to your account is disabled on this server"
+            )
+        elif self.config.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            raise SynapseError(
+                400,
+                "This homeserver is not validating threepids. Use an identity server "
+                "instead.",
+            )
+
+        sid = parse_string(request, "sid", required=True)
+        token = parse_string(request, "token", required=True)
+        client_secret = parse_string(request, "client_secret", required=True)
+        assert_valid_client_secret(client_secret)
+
+        # Attempt to validate a 3PID session
+        try:
+            # Mark the session as valid
+            next_link = await self.store.validate_threepid_session(
+                sid, client_secret, token, self.clock.time_msec()
+            )
+
+            # Perform a 302 redirect if next_link is set
+            if next_link:
+                request.setResponseCode(302)
+                request.setHeader("Location", next_link)
+                finish_request(request)
+                return None
+
+            # Otherwise show the success template
+            html = self.config.email_add_threepid_template_success_html_content
+            status_code = 200
+        except ThreepidValidationError as e:
+            status_code = e.code
+
+            # Show a failure page with a reason
+            template_vars = {"failure_reason": e.msg}
+            html = self._failure_email_template.render(**template_vars)
+
+        respond_with_html(request, status_code, html)
+
+
+class AddThreepidMsisdnSubmitTokenServlet(RestServlet):
+    """Handles 3PID validation token submission for adding a phone number to a user's
+    account
+    """
+
+    PATTERNS = client_patterns(
+        "/add_threepid/msisdn/submit_token$", releases=(), unstable=True
+    )
+
+    def __init__(self, hs):
+        """
+        Args:
+            hs (synapse.server.HomeServer): server
+        """
+        super().__init__()
+        self.config = hs.config
+        self.clock = hs.get_clock()
+        self.store = hs.get_datastore()
+        self.identity_handler = hs.get_identity_handler()
+
+    async def on_POST(self, request):
+        if not self.config.account_threepid_delegate_msisdn:
+            raise SynapseError(
+                400,
+                "This homeserver is not validating phone numbers. Use an identity server "
+                "instead.",
+            )
+
+        body = parse_json_object_from_request(request)
+        assert_params_in_dict(body, ["client_secret", "sid", "token"])
+        assert_valid_client_secret(body["client_secret"])
+
+        # Proxy submit_token request to msisdn threepid delegate
+        response = await self.identity_handler.proxy_msisdn_submit_token(
+            self.config.account_threepid_delegate_msisdn,
+            body["client_secret"],
+            body["sid"],
+            body["token"],
+        )
+        return 200, response
+
+
+class ThreepidRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.identity_handler = hs.get_identity_handler()
+        self.auth = hs.get_auth()
+        self.auth_handler = hs.get_auth_handler()
+        self.datastore = self.hs.get_datastore()
+
+    async def on_GET(self, request):
+        requester = await self.auth.get_user_by_req(request)
+
+        threepids = await self.datastore.user_get_threepids(requester.user.to_string())
+
+        return 200, {"threepids": threepids}
+
+    async def on_POST(self, request):
+        if not self.hs.config.enable_3pid_changes:
+            raise SynapseError(
+                400, "3PID changes are disabled on this server", Codes.FORBIDDEN
+            )
+
+        requester = await self.auth.get_user_by_req(request)
+        user_id = requester.user.to_string()
+        body = parse_json_object_from_request(request)
+
+        threepid_creds = body.get("threePidCreds") or body.get("three_pid_creds")
+        if threepid_creds is None:
+            raise SynapseError(
+                400, "Missing param three_pid_creds", Codes.MISSING_PARAM
+            )
+        assert_params_in_dict(threepid_creds, ["client_secret", "sid"])
+
+        sid = threepid_creds["sid"]
+        client_secret = threepid_creds["client_secret"]
+        assert_valid_client_secret(client_secret)
+
+        validation_session = await self.identity_handler.validate_threepid_session(
+            client_secret, sid
+        )
+        if validation_session:
+            await self.auth_handler.add_threepid(
+                user_id,
+                validation_session["medium"],
+                validation_session["address"],
+                validation_session["validated_at"],
+            )
+            return 200, {}
+
+        raise SynapseError(
+            400, "No validated 3pid session found", Codes.THREEPID_AUTH_FAILED
+        )
+
+
+class ThreepidAddRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid/add$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.identity_handler = hs.get_identity_handler()
+        self.auth = hs.get_auth()
+        self.auth_handler = hs.get_auth_handler()
+
+    @interactive_auth_handler
+    async def on_POST(self, request):
+        if not self.hs.config.enable_3pid_changes:
+            raise SynapseError(
+                400, "3PID changes are disabled on this server", Codes.FORBIDDEN
+            )
+
+        requester = await self.auth.get_user_by_req(request)
+        user_id = requester.user.to_string()
+        body = parse_json_object_from_request(request)
+
+        assert_params_in_dict(body, ["client_secret", "sid"])
+        sid = body["sid"]
+        client_secret = body["client_secret"]
+        assert_valid_client_secret(client_secret)
+
+        await self.auth_handler.validate_user_via_ui_auth(
+            requester,
+            request,
+            body,
+            "add a third-party identifier to your account",
+        )
+
+        validation_session = await self.identity_handler.validate_threepid_session(
+            client_secret, sid
+        )
+        if validation_session:
+            await self.auth_handler.add_threepid(
+                user_id,
+                validation_session["medium"],
+                validation_session["address"],
+                validation_session["validated_at"],
+            )
+            return 200, {}
+
+        raise SynapseError(
+            400, "No validated 3pid session found", Codes.THREEPID_AUTH_FAILED
+        )
+
+
+class ThreepidBindRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid/bind$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.identity_handler = hs.get_identity_handler()
+        self.auth = hs.get_auth()
+
+    async def on_POST(self, request):
+        body = parse_json_object_from_request(request)
+
+        assert_params_in_dict(body, ["id_server", "sid", "client_secret"])
+        id_server = body["id_server"]
+        sid = body["sid"]
+        id_access_token = body.get("id_access_token")  # optional
+        client_secret = body["client_secret"]
+        assert_valid_client_secret(client_secret)
+
+        requester = await self.auth.get_user_by_req(request)
+        user_id = requester.user.to_string()
+
+        await self.identity_handler.bind_threepid(
+            client_secret, sid, user_id, id_server, id_access_token
+        )
+
+        return 200, {}
+
+
+class ThreepidUnbindRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid/unbind$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.identity_handler = hs.get_identity_handler()
+        self.auth = hs.get_auth()
+        self.datastore = self.hs.get_datastore()
+
+    async def on_POST(self, request):
+        """Unbind the given 3pid from a specific identity server, or identity servers that are
+        known to have this 3pid bound
+        """
+        requester = await self.auth.get_user_by_req(request)
+        body = parse_json_object_from_request(request)
+        assert_params_in_dict(body, ["medium", "address"])
+
+        medium = body.get("medium")
+        address = body.get("address")
+        id_server = body.get("id_server")
+
+        # Attempt to unbind the threepid from an identity server. If id_server is None, try to
+        # unbind from all identity servers this threepid has been added to in the past
+        result = await self.identity_handler.try_unbind_threepid(
+            requester.user.to_string(),
+            {"address": address, "medium": medium, "id_server": id_server},
+        )
+        return 200, {"id_server_unbind_result": "success" if result else "no-support"}
+
+
+class ThreepidDeleteRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid/delete$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.auth = hs.get_auth()
+        self.auth_handler = hs.get_auth_handler()
+
+    async def on_POST(self, request):
+        if not self.hs.config.enable_3pid_changes:
+            raise SynapseError(
+                400, "3PID changes are disabled on this server", Codes.FORBIDDEN
+            )
+
+        body = parse_json_object_from_request(request)
+        assert_params_in_dict(body, ["medium", "address"])
+
+        requester = await self.auth.get_user_by_req(request)
+        user_id = requester.user.to_string()
+
+        try:
+            ret = await self.auth_handler.delete_threepid(
+                user_id, body["medium"], body["address"], body.get("id_server")
+            )
+        except Exception:
+            # NB. This endpoint should succeed if there is nothing to
+            # delete, so it should only throw if something is wrong
+            # that we ought to care about.
+            logger.exception("Failed to remove threepid")
+            raise SynapseError(500, "Failed to remove threepid")
+
+        if ret:
+            id_server_unbind_result = "success"
+        else:
+            id_server_unbind_result = "no-support"
+
+        return 200, {"id_server_unbind_result": id_server_unbind_result}
+
+
+def assert_valid_next_link(hs: "HomeServer", next_link: str):
+    """
+    Raises a SynapseError if a given next_link value is invalid
+
+    next_link is valid if the scheme is http(s) and the next_link.domain_whitelist config
+    option is either empty or contains a domain that matches the one in the given next_link
+
+    Args:
+        hs: The homeserver object
+        next_link: The next_link value given by the client
+
+    Raises:
+        SynapseError: If the next_link is invalid
+    """
+    valid = True
+
+    # Parse the contents of the URL
+    next_link_parsed = urlparse(next_link)
+
+    # Scheme must not point to the local drive
+    if next_link_parsed.scheme == "file":
+        valid = False
+
+    # If the domain whitelist is set, the domain must be in it
+    if (
+        valid
+        and hs.config.next_link_domain_whitelist is not None
+        and next_link_parsed.hostname not in hs.config.next_link_domain_whitelist
+    ):
+        valid = False
+
+    if not valid:
+        raise SynapseError(
+            400,
+            "'next_link' domain not included in whitelist, or not http(s)",
+            errcode=Codes.INVALID_PARAM,
+        )
+
+
+class WhoamiRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/whoami$")
+
+    def __init__(self, hs):
+        super().__init__()
+        self.auth = hs.get_auth()
+
+    async def on_GET(self, request):
+        requester = await self.auth.get_user_by_req(request)
+
+        response = {"user_id": requester.user.to_string()}
+
+        # Appservices and similar accounts do not have device IDs
+        # that we can report on, so exclude them for compliance.
+        if requester.device_id is not None:
+            response["device_id"] = requester.device_id
+
+        return 200, response
+
+
+def register_servlets(hs, http_server):
+    EmailPasswordRequestTokenRestServlet(hs).register(http_server)
+    PasswordRestServlet(hs).register(http_server)
+    DeactivateAccountRestServlet(hs).register(http_server)
+    EmailThreepidRequestTokenRestServlet(hs).register(http_server)
+    MsisdnThreepidRequestTokenRestServlet(hs).register(http_server)
+    AddThreepidEmailSubmitTokenServlet(hs).register(http_server)
+    AddThreepidMsisdnSubmitTokenServlet(hs).register(http_server)
+    ThreepidRestServlet(hs).register(http_server)
+    ThreepidAddRestServlet(hs).register(http_server)
+    ThreepidBindRestServlet(hs).register(http_server)
+    ThreepidUnbindRestServlet(hs).register(http_server)
+    ThreepidDeleteRestServlet(hs).register(http_server)
+    WhoamiRestServlet(hs).register(http_server)