Add JID escaping support.

sleekxmpp/jid.py

@@ -29,6 +29,30 @@ ILLEGAL_CHARS = '\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r' + \
 
 JID_PATTERN = "^(?:([^\"&'/:<>@]{1,1023})@)?([^/@]{1,1023})(?:/(.{1,1023}))?$"
 
+JID_ESCAPE_SEQUENCES = set(['\\20', '\\22', '\\26', '\\27', '\\2f',
+                            '\\3a', '\\3c', '\\3e', '\\40', '\\5c'])
+
+JID_ESCAPE_TRANSFORMATIONS = {' ': '\\20',
+                              '"': '\\22',
+                              '&': '\\26',
+                              "'": '\\27',
+                              '/': '\\2f',
+                              ':': '\\3a',
+                              '<': '\\3c',
+                              '>': '\\3e',
+                              '@': '\\40'}
+
+JID_UNESCAPE_TRANSFORMATIONS = {'\\20': ' ',
+                                '\\22': '"',
+                                '\\26': '&',
+                                '\\27': "'",
+                                '\\2f': '/',
+                                '\\3a': ':',
+                                '\\3c': '<',
+                                '\\3e': '>',
+                                '\\40': '@',
+                                '\\5c': '\\'}
+
 
 nodeprep = stringprep_profiles.create(
     nfkc=True,
@@ -70,21 +94,33 @@ resourceprep = stringprep_profiles.create(
     unassigned=[stringprep.in_table_a1])
 
 
-class InvalidJID(ValueError):
+def _parse_jid(data):
-    pass
-
-
-def parse_jid(data):
     """
     Parse string data into the node, domain, and resource
     components of a JID.
     """
     match = re.match(JID_PATTERN, data)
     if not match:
-        raise InvalidJID
+        raise InvalidJID('JID could not be parsed')
 
     (node, domain, resource) = match.groups()
 
+    _validate_node(node)
+    _validate_domain(domain)
+    _validate_resource(resource)
+
+    return node, domain, resource
+
+
+def _validate_node(node):
+    try:
+        if node is not None:
+            node = nodeprep(node)
+    except stringprep_profiles.StringPrepError:
+        raise InvalidJID('Invalid local part')
+
+
+def _validate_domain(domain):
     ip_addr = False
 
     try:
@@ -107,27 +143,122 @@ def parse_jid(data):
                 label = encodings.idna.nameprep(label)
                 encodings.idna.ToASCII(label)
             except UnicodeError:
-                raise InvalidJID
+                raise InvalidJID('Could not encode domain as ASCII')
 
             for char in label:
                 if char in ILLEGAL_CHARS:
-                    raise InvalidJID
+                    raise InvalidJID('Domain contains illegar characters')
 
             if '-' in (label[0], label[-1]):
-                raise InvalidJID
+                raise InvalidJID('Domain started or ended with -')
 
             domain_parts.append(label)
         domain = '.'.join(domain_parts)
 
+    if not domain:
+        raise InvalidJID('Missing domain')
+
+
+def _validate_resource(resource):
     try:
-        if node is not None:
-            node = nodeprep(node)
         if resource is not None:
             resource = resourceprep(resource)
     except stringprep_profiles.StringPrepError:
-        raise InvalidJID
+        raise InvalidJID('Invalid resource')
 
-    return node, domain, resource
+
+def _escape_node(node):
+    result = []
+
+    for i, char in enumerate(node):
+        if char == '\\':
+            if ''.join((data[i:i+3])) in JID_ESCAPE_SEQUENCES:
+                result.append('\\5c')
+                continue
+        result.append(char)
+
+    for i, char in enumerate(result):
+        result[i] = JID_ESCAPE_TRANSFORMATIONS.get(char, char)
+
+    escaped = ''.join(result)
+
+    if escaped.startswith('\\20') or escaped.endswith('\\20'):
+        raise InvalidJID('Escaped local part starts or ends with "\\20"')
+
+    _validate_node(escaped)
+
+    return escaped
+
+
+def _unescape_node(node):
+    unescaped = []
+    seq = ''
+    for i, char in enumerate(node):
+        if char == '\\':
+            seq = node[i:i+3]
+            if seq not in JID_ESCAPE_SEQUENCES:
+                seq = ''
+        if seq:
+            if len(seq) == 3:
+                unescaped.append(JID_UNESCAPE_TRANSFORMATIONS.get(seq, char))
+
+            # Pop character off the escape sequence, and ignore it
+            seq = seq[1:]
+        else:
+            unescaped.append(char)
+    unescaped = ''.join(unescaped)
+
+    return unescaped
+
+
+def _format_jid(local=None, domain=None, resource=None):
+    result = []
+    if local:
+        result.append(local)
+        result.append('@')
+    if domain:
+        result.append(domain)
+    if resource:
+        result.append('/')
+        result.append(resource)
+    return ''.join(result)
+
+
+class InvalidJID(ValueError):
+    pass
+
+
+class UnescapedJID(object):
+
+    def __init__(self, local, domain, resource):
+        self._jid = (local, domain, resource)
+
+    def __getattr__(self, name):
+        """
+        :param name: one of: user, server, domain, resource,
+                     full, or bare.
+        """
+        if name == 'resource':
+            return self._jid[2] or ''
+        elif name in ('user', 'username', 'local', 'node'):
+            return self._jid[0] or ''
+        elif name in ('server', 'domain', 'host'):
+            return self._jid[1] or ''
+        elif name in ('full', 'jid'):
+            return _format_jid(*self._jid)
+        elif name == 'bare':
+            return _format_jid(self._jid[0], self._jid[1])
+        elif name == '_jid':
+            return getattr(super(JID, self), '_jid')
+        else:
+            return None
+
+    def __str__(self):
+        """Use the full JID as the string value."""
+        return _format_jid(*self._jid)
+
+    def __repr__(self):
+        return self.__str__()
 
 
 class JID(object):
@@ -157,21 +288,37 @@ class JID(object):
     :param string jid: A string of the form ``'[user@]domain[/resource]'``.
     """
 
-    def __init__(self, jid=None, local=None, domain=None, resource=None):
+    def __init__(self, jid=None, **kwargs):
         """Initialize a new JID"""
         self._jid = (None, None, None)
 
         if jid is None or jid == '':
             jid = (None, None, None)
         elif not isinstance(jid, JID):
-            jid = parse_jid(jid)
+            jid = _parse_jid(jid)
         else:
             jid = jid._jid
 
-        orig_local, orig_domain, orig_resource = jid
+        local, domain, resource = jid
-        self._jid = (local or orig_local or None,
+        validated = True
-                     domain or orig_domain or None,
+
-                     resource or orig_resource or None)
+        local = kwargs.get('local', local)
+        domain = kwargs.get('domain', domain)
+        resource = kwargs.get('resource', resource)
+
+        if 'local' in kwargs:
+            local = _escape_node(local)
+        if 'domain' in kwargs:
+            _validate_domain(domain)
+        if 'resource' in kwargs:
+            _validate_resource(resource)
+
+        self._jid = (local, domain, resource)
+
+    def unescape(self):
+        return UnescapedJID(_unescape_node(self._jid[0]),
+                            self._jid[1],
+                            self._jid[2])
 
     def regenerate(self):
         """Deprecated"""
@@ -185,8 +332,7 @@ class JID(object):
         self._jid = JID(data)._jid
 
     def __getattr__(self, name):
-        """handle getting the jid values, using cache if available.
+        """
-
         :param name: one of: user, server, domain, resource,
                      full, or bare.
         """
@@ -197,16 +343,16 @@ class JID(object):
         elif name in ('server', 'domain', 'host'):
             return self._jid[1] or ''
         elif name in ('full', 'jid'):
-            return str(self)
+            return _format_jid(*self._jid)
         elif name == 'bare':
-            return str(JID(local=self._jid[0],
+            return _format_jid(self._jid[0], self._jid[1])
-                           domain=self._jid[1]))
+        elif name == '_jid':
+            return getattr(super(JID, self), '_jid')
         else:
-            object.__getattr__(self, name)
+            return None
 
     def __setattr__(self, name, value):
-        """handle getting the jid values, using cache if available.
+        """
-
         :param name: one of: ``user``, ``username``, ``local``,
                              ``node``, ``server``, ``domain``, ``host``,
                              ``resource``, ``full``, ``jid``, or ``bare``.
@@ -223,21 +369,12 @@ class JID(object):
         elif name == 'bare':
             parsed = JID(value)._jid
             self._jid = (parsed[0], parsed[1], self._jid[2])
-        else:
+        elif name == '_jid':
-            object.__setattr__(self, name, value)
+            super(JID, self).__setattr__('_jid', value)
 
     def __str__(self):
         """Use the full JID as the string value."""
-        result = []
+        return _format_jid(*self._jid)
-        if self._jid[0]:
-            result.append(self._jid[0])
-            result.append('@')
-        if self._jid[1]:
-            result.append(self._jid[1])
-        if self._jid[2]:
-            result.append('/')
-            result.append(self._jid[2])
-        return ''.join(result)
 
     def __repr__(self):
         return self.__str__()
@@ -246,6 +383,9 @@ class JID(object):
         """
         Two JIDs are considered equal if they have the same full JID value.
         """
+        if isinstance(other, UnescapedJID):
+            return False
+
         other = JID(other)
         return self._jid == other._jid