Add support for a profile change page

snikket_web/xmpputil.py

@@ -0,0 +1,130 @@
+import typing
+
+import xml.etree.ElementTree as ET
+
+from quart import abort
+import quart.exceptions
+
+
+TAG_XMPP_ERROR = "error"
+
+NS_XMPP_ERROR_CONDITION = "urn:ietf:params:xml:ns:xmpp-stanzas"
+TAG_XMPP_ERROR_ITEM_NOT_FOUND = "{{{}}}item-not-found".format(NS_XMPP_ERROR_CONDITION)
+TAG_XMPP_ERROR_TEXT =  "{{{}}}text".format(TAG_XMPP_ERROR_ITEM_NOT_FOUND)
+
+ERROR_CODE_MAP = {
+    TAG_XMPP_ERROR_ITEM_NOT_FOUND: 404,
+}
+
+NS_PUBSUB = "http://jabber.org/protocol/pubsub"
+TAG_PUBSUB = "{{{}}}pubsub".format(NS_PUBSUB)
+TAG_PUBSUB_ITEM = "{{{}}}item".format(NS_PUBSUB)
+TAG_PUBSUB_ITEMS = "{{{}}}items".format(NS_PUBSUB)
+
+NS_USER_NICKNAME = "http://jabber.org/protocol/nick"
+TAG_USER_NICKNAME_NICK = "{{{}}}nick".format(NS_USER_NICKNAME)
+
+
+def split_jid(s):
+    bare, sep, resource = s.partition("/")
+    if not sep:
+        resource = None
+    localpart, sep, domain = bare.partition("@")
+    if not sep:
+        domain = localpart
+        localpart = None
+    return localpart, domain, resource
+
+
+def raise_iq_error(err: ET.Element):
+    err_condition_el = None
+    err_text_el = None
+    err_app_def_condition_el = None
+
+    for el in err:
+        if el.tag == TAG_XMPP_ERROR_TEXT:
+            err_text_el = el
+        elif el.tag.startswith("{{{}}}".format(NS_XMPP_ERROR_CONDITION)):
+            err_condition_el = el
+        else:
+            err_app_def_condition_el = el
+
+    abort(ERROR_CODE_MAP.get(err_condition_el.tag, 500),
+          err_condition_el.tag)
+
+
+def extract_iq_reply(tree: ET.Element,
+                     require_tag: str = None) -> typing.Optional[ET.Element]:
+    iq_type = tree.get("type")
+    if iq_type == "error":
+        error = tree.find(TAG_XMPP_ERROR)
+        if error is not None:
+            raise raise_iq_error(error)
+        raise abort(500, "malformed reply")
+    elif iq_type == "result":
+        if len(tree) > 0:
+            reply_el = tree[0]
+            if require_tag and reply_el.tag != require_tag:
+                raise abort(500, "unexpected reply")
+            return reply_el
+        if require_tag:
+            raise abort(500, "unexpected reply")
+        return None
+    else:
+        raise abort(500, "unsupported reply")
+
+
+def make_password_change_request(jid, password):
+    username, domain, _ = split_jid(jid)
+    # XXX: this is due to a problem with mod_rest / mod_register in prosody:
+    # it doesn’t recognize the password change stanza unless we send it to
+    # the account JID.
+    req = ET.Element("iq", to="{}@{}".format(username, domain), type="set")
+    q = ET.SubElement(req, "query", xmlns="jabber:iq:register")
+    ET.SubElement(q, "username").text = username
+    ET.SubElement(q, "password").text = password
+    return ET.tostring(req)
+
+
+def make_nickname_set_request(to, nickname):
+    req = ET.Element("iq", type="set", to=to)
+    q = ET.SubElement(req, "pubsub", xmlns="http://jabber.org/protocol/pubsub")
+    publish = ET.SubElement(q, "publish", node="http://jabber.org/protocol/nick")
+    item = ET.SubElement(publish, "item")
+    ET.SubElement(
+        item,
+        "nick",
+        xmlns="http://jabber.org/protocol/nick"
+    ).text = nickname
+
+    return ET.tostring(req)
+
+
+def make_nickname_get_request(to):
+    req = ET.Element("iq", type="get", to=to)
+    q = ET.SubElement(req, "pubsub", xmlns="http://jabber.org/protocol/pubsub")
+    items = ET.SubElement(q, "items", node="http://jabber.org/protocol/nick", max_items="1")
+
+    return ET.tostring(req)
+
+
+def _require_child(t: ET.Element, tag: str) -> ET.Element:
+    el = t.find(tag)
+    if el is None:
+        raise abort(500, "malformed reply")
+    return el
+
+
+def extract_nickname_get_reply(iq_tree):
+    try:
+        pubsub = extract_iq_reply(iq_tree, TAG_PUBSUB)
+    except quart.exceptions.NotFound:
+        return None
+
+    items = _require_child(pubsub, TAG_PUBSUB_ITEMS)
+    if len(items) == 0:
+        return None
+
+    item = _require_child(items, TAG_PUBSUB_ITEM)
+    nick = _require_child(item, TAG_USER_NICKNAME_NICK)
+    return nick.text