Implement username availability checker

Outlined here: https://github.com/vector-im/riot-web/issues/3605#issuecomment-298679388

```HTTP
GET /_matrix/.../register/available
{
    "username": "desiredlocalpart123"
}
```

If available, the response looks like
```HTTP
HTTP/1.1 200 OK
{
    "available": true
}
```

Otherwise,
```HTTP
HTTP/1.1 429
{
    "errcode": "M_LIMIT_EXCEEDED",
    "error": "Too Many Requests",
    "retry_after_ms": 2000
}
```
or
```HTTP
HTTP/1.1 400
{
    "errcode": "M_USER_IN_USE",
    "error": "User ID already taken."
}

```
or
```HTTP
HTTP/1.1 400
{
    "errcode": "M_INVALID_USERNAME",
    "error": "Some reason for username being invalid"
}
```
This commit is contained in:
Luke Barnard 2017-05-03 11:55:44 +01:00
parent 82475a18d9
commit 34ed4f4206

View File

@ -31,6 +31,7 @@ import logging
import hmac
from hashlib import sha1
from synapse.util.async import run_on_reactor
from synapse.util.ratelimitutils import FederationRateLimiter
# We ought to be using hmac.compare_digest() but on older pythons it doesn't
@ -115,6 +116,40 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet):
defer.returnValue((200, ret))
class UsernameAvailabilityRestServlet(RestServlet):
PATTERNS = client_v2_patterns("/register/available")
def __init__(self, hs):
"""
Args:
hs (synapse.server.HomeServer): server
"""
super(UsernameAvailabilityRestServlet, self).__init__()
self.hs = hs
self.registration_handler = hs.get_handlers().registration_handler
self.ratelimiter = FederationRateLimiter(
hs.get_clock(),
window_size=2000, # Time window of 2s
sleep_limit=1, # Artificially delay requests if rate > sleep_limit/window_size
sleep_msec=1000, # Amount of artificial delay to apply
reject_limit=1, # Error with 429 if more than reject_limit requests are queued
concurrent_requests=1, # Allow 1 request at a time
)
@defer.inlineCallbacks
def on_GET(self, request):
ip = self.hs.get_ip_from_request(request)
with self.ratelimiter.ratelimit(ip) as wait_deferred:
yield wait_deferred
body = parse_json_object_from_request(request)
assert_params_in_request(body, ['username'])
yield self.registration_handler.check_username(body['username'])
defer.returnValue((200, {"available": True}))
class RegisterRestServlet(RestServlet):
PATTERNS = client_v2_patterns("/register$")
@ -555,4 +590,5 @@ class RegisterRestServlet(RestServlet):
def register_servlets(hs, http_server):
EmailRegisterRequestTokenRestServlet(hs).register(http_server)
MsisdnRegisterRequestTokenRestServlet(hs).register(http_server)
UsernameAvailabilityRestServlet(hs).register(http_server)
RegisterRestServlet(hs).register(http_server)