Properly check Jids everywhere

17 files changed, 464 insertions, 124 deletions

diff --git a/xmpp-vala/CMakeLists.txt b/xmpp-vala/CMakeLists.txt
index e059b068..246f0108 100644
--- a/xmpp-vala/CMakeLists.txt
+++ b/xmpp-vala/CMakeLists.txt
@@ -4,6 +4,7 @@ find_packages(ENGINE_PACKAGES REQUIRED
     GIO
     GLib
     GObject
+    ICU
 )
 
 set(ENGINE_DEFINITIONS "")
@@ -15,6 +16,7 @@ if(GIO_VERSION VERSION_GREATER "2.60")
 else()
     message(STATUS "No ALPN support, needs GIO >= 2.60")
 endif()
+set(ENGINE_EXTRA_OPTIONS ${MAIN_EXTRA_OPTIONS} --vapidir=${CMAKE_CURRENT_SOURCE_DIR}/vapi)
 
 vala_precompile(ENGINE_VALA_C
 SOURCES
@@ -104,6 +106,8 @@ CUSTOM_VAPIS
     "${CMAKE_CURRENT_SOURCE_DIR}/src/glib_fixes.vapi"
 DEFINITIONS
     ${ENGINE_DEFINITIONS}
+OPTIONS
+    ${ENGINE_EXTRA_OPTIONS}
 )
 
 add_custom_target(xmpp-vala-vapi
@@ -128,12 +132,15 @@ if(BUILD_TESTS)
         "tests/common.vala"
         "tests/testcase.vala"
 
+        "tests/jid.vala"
         "tests/stanza.vala"
         "tests/util.vala"
     CUSTOM_VAPIS
         ${CMAKE_BINARY_DIR}/exports/xmpp-vala_internal.vapi
     PACKAGES
         ${ENGINE_PACKAGES}
+    OPTIONS
+        ${ENGINE_EXTRA_OPTIONS}
     )
 
     add_definitions(${VALA_CFLAGS})
diff --git a/xmpp-vala/src/core/xmpp_stream.vala b/xmpp-vala/src/core/xmpp_stream.vala
index 97d00004..39754ba1 100644
--- a/xmpp-vala/src/core/xmpp_stream.vala
+++ b/xmpp-vala/src/core/xmpp_stream.vala
@@ -44,7 +44,11 @@ public class XmppStream {
     }
 
     public async void connect(string? remote_name = null) throws IOStreamError {
-        if (remote_name != null) this.remote_name = Jid.parse(remote_name);
+        try {
+            if (remote_name != null) this.remote_name = new Jid(remote_name);
+        } catch (InvalidJidError e) {
+            throw new IOStreamError.CONNECT(@"Invalid remote name \"$remote_name\": $(e.message)");
+        }
         attach_negotation_modules();
         try {
             int min_priority = -1;
diff --git a/xmpp-vala/src/module/bind.vala b/xmpp-vala/src/module/bind.vala
index a3b0762b..89398bfb 100644
--- a/xmpp-vala/src/module/bind.vala
+++ b/xmpp-vala/src/module/bind.vala
@@ -5,11 +5,11 @@ namespace Xmpp.Bind {
     public class Module : XmppStreamNegotiationModule {
         public static ModuleIdentity<Module> IDENTITY = new ModuleIdentity<Module>(NS_URI, "bind_module");
 
-        public string requested_resource { get; set; }
+        public string? requested_resource { get; set; }
 
         public signal void bound_to_resource(XmppStream stream, Jid my_jid);
 
-        public Module(string requested_resource) {
+        public Module(string? requested_resource) {
             this.requested_resource = requested_resource;
         }
 
@@ -18,9 +18,13 @@ namespace Xmpp.Bind {
             if (flag == null || flag.finished) return;
 
             if (iq.type_ == Iq.Stanza.TYPE_RESULT) {
-                flag.my_jid = Jid.parse(iq.stanza.get_subnode("jid", NS_URI, true).get_string_content());
-                flag.finished = true;
-                bound_to_resource(stream, flag.my_jid);
+                try {
+                    flag.my_jid = new Jid(iq.stanza.get_subnode("jid", NS_URI, true).get_string_content());
+                    flag.finished = true;
+                    bound_to_resource(stream, flag.my_jid);
+                } catch (InvalidJidError e) {
+                    warning("Received invalid Jid when binding: %s", e.message);
+                }
             }
         }
 
@@ -32,7 +36,9 @@ namespace Xmpp.Bind {
             if (bind != null) {
                 var flag = new Flag();
                 StanzaNode bind_node = new StanzaNode.build("bind", NS_URI).add_self_xmlns();
-                bind_node.put_node(new StanzaNode.build("resource", NS_URI).put_node(new StanzaNode.text(requested_resource)));
+                if (requested_resource != null) {
+                    bind_node.put_node(new StanzaNode.build("resource", NS_URI).put_node(new StanzaNode.text(requested_resource)));
+                }
                 stream.get_module(Iq.Module.IDENTITY).send_iq(stream, new Iq.Stanza.set(bind_node), iq_response_stanza);
                 stream.add_flag(flag);
             }
diff --git a/xmpp-vala/src/module/conference.vala b/xmpp-vala/src/module/conference.vala
index ee1be6b6..9b1172d8 100644
--- a/xmpp-vala/src/module/conference.vala
+++ b/xmpp-vala/src/module/conference.vala
@@ -1,14 +1,14 @@
 namespace Xmpp {
 
 public class Conference : Object {
-    public virtual Jid jid { get; set; }
+    public virtual Jid? jid { get; set; }
     public virtual bool autojoin { get; set; }
     public virtual string? nick { get; set; }
     public virtual string? name { get; set; }
     public virtual string? password { get; set; }
 
     public static bool equal_func(Conference a, Conference b) {
-        return a.jid.equals(b.jid);
+        return Jid.equals_func(a.jid, b.jid);
     }
 
     public static uint hash_func(Conference a) {
diff --git a/xmpp-vala/src/module/jid.vala b/xmpp-vala/src/module/jid.vala
index c20e0202..569be54f 100644
--- a/xmpp-vala/src/module/jid.vala
+++ b/xmpp-vala/src/module/jid.vala
@@ -6,60 +6,126 @@ public class Jid {
     public string? resourcepart;
 
     public Jid bare_jid {
-        owned get { return is_bare() ? this : new Jid.components(localpart, domainpart, null); }
+    owned get { return is_bare() ? this : new Jid.intern(null, localpart, domainpart, null); }
     }
 
     public Jid domain_jid {
-        owned get { return is_domain() ? this : new Jid.components(null, domainpart, null); }
+    owned get { return is_domain() ? this : new Jid.intern(domainpart, null, domainpart, null); }
     }
 
     private string jid;
 
-    public Jid(string jid) {
-        Jid? parsed = Jid.parse(jid);
-        string? localpart = parsed != null ? (owned) parsed.localpart : null;
-        string domainpart = parsed != null ? (owned) parsed.domainpart : jid;
-        string? resourcepart = parsed != null ? (owned) parsed.resourcepart : null;
-        this.intern(jid, (owned) localpart, (owned) domainpart, (owned) resourcepart);
+    public Jid(string jid) throws InvalidJidError {
+        int slash_index = jid.index_of("/");
+        int at_index = jid.index_of("@");
+        if (at_index > slash_index && slash_index != -1) at_index = -1;
+        string resourcepart = slash_index < 0 ? null : jid.slice(slash_index + 1, jid.length);
+        string localpart = at_index < 0 ? null : jid.slice(0, at_index);
+        string domainpart;
+        if (at_index < 0) {
+            if (slash_index < 0) {
+                domainpart = jid;
+            } else {
+                domainpart = jid.slice(0, slash_index);
+            }
+        } else {
+            if (slash_index < 0) {
+                domainpart = jid.slice(at_index + 1, jid.length);
+            } else {
+                domainpart = jid.slice(at_index + 1, slash_index);
+            }
+        }
+
+        this.components(localpart, domainpart, resourcepart);
     }
 
-    private Jid.intern(owned string jid, owned string? localpart, owned string domainpart, owned string? resourcepart) {
+    private Jid.intern(owned string? jid, owned string? localpart, owned string domainpart, owned string? resourcepart) {
         this.jid = (owned) jid;
         this.localpart = (owned) localpart;
         this.domainpart = (owned) domainpart;
         this.resourcepart = (owned) resourcepart;
     }
 
-    public Jid.components(owned string? localpart, owned string domainpart, owned string? resourcepart) {
-        string jid = domainpart;
-        if (localpart != null) {
-            jid = @"$localpart@$jid";
+    public Jid.components(string? localpart, string domainpart, string? resourcepart) throws InvalidJidError {
+        // TODO verify and normalize all parts
+        if (domainpart.length == 0) throw new InvalidJidError.EMPTY_DOMAIN("Domain is empty");
+        if (localpart != null && localpart.length == 0) throw new InvalidJidError.EMPTY_LOCAL("Localpart is empty but non-null");
+        if (resourcepart != null && resourcepart.length == 0) throw new InvalidJidError.EMPTY_RESOURCE("Resource is empty but non-null");
+        string domain = domainpart[domainpart.length - 1] == '.' ? domainpart.substring(0, domainpart.length - 1) : domainpart;
+        if (domain.contains("xn--")) {
+            domain = idna_decode(domain);
         }
-        if (resourcepart != null) {
-            jid = @"$jid/$resourcepart";
+        this.localpart = prepare(localpart, ICU.PrepType.RFC3920_NODEPREP);
+        this.domainpart = prepare(domain, ICU.PrepType.RFC3491_NAMEPREP);
+        this.resourcepart = prepare(resourcepart, ICU.PrepType.RFC3920_RESOURCEPREP);
+        idna_verify(this.domainpart);
+    }
+
+    private static string idna_decode(string src) throws InvalidJidError {
+        try {
+            ICU.ErrorCode status = ICU.ErrorCode.ZERO_ERROR;
+            long src16_length = 0;
+            string16 src16 = src.to_utf16(-1, null, out src16_length);
+            ICU.Char[] dest16 = new ICU.Char[src16_length];
+            ICU.ParseError error;
+            long dest16_length = ICU.IDNA.IDNToUnicode(src16, (int32) src16_length, dest16, dest16.length, ICU.IDNAOptions.DEFAULT, out error, ref status);
+            if (status == ICU.ErrorCode.INVALID_CHAR_FOUND) {
+                throw new InvalidJidError.INVALID_CHAR("Found invalid character");
+            } else if (status != ICU.ErrorCode.ZERO_ERROR) {
+                throw new InvalidJidError.UNKNOWN(@"Unknown error: $(status.errorName())");
+            } else if (dest16_length < 0) {
+                throw new InvalidJidError.UNKNOWN("Unknown error");
+            }
+            return ((string16) dest16).to_utf8(dest16_length, null, null);
+        } catch (ConvertError e) {
+            throw new InvalidJidError.INVALID_CHAR(@"Conversion error: $(e.message)");
         }
-        this.jid = jid;
-        this.localpart = (owned) localpart;
-        this.domainpart = (owned) domainpart;
-        this.resourcepart = (owned) resourcepart;
     }
 
-    public static Jid? parse(string jid) {
-        int slash_index = jid.index_of("/");
-        string resourcepart = slash_index == -1 ? null : jid.slice(slash_index + 1, jid.length);
-        string bare_jid = slash_index == -1 ? jid : jid.slice(0, slash_index);
-        int at_index = bare_jid.index_of("@");
-        string localpart = at_index == -1 ? null : bare_jid.slice(0, at_index);
-        string domainpart = at_index == -1 ? bare_jid : bare_jid.slice(at_index + 1, bare_jid.length);
-
-        if (domainpart == "") return null;
-        if (slash_index != -1 && resourcepart == "") return null;
-        if (at_index != -1 && localpart == "") return null;
+    private static void idna_verify(string src) throws InvalidJidError {
+        try {
+            ICU.ErrorCode status = ICU.ErrorCode.ZERO_ERROR;
+            long src16_length = 0;
+            string16 src16 = src.to_utf16(-1, null, out src16_length);
+            ICU.Char[] dest16 = new ICU.Char[256];
+            ICU.ParseError error;
+            long dest16_length = ICU.IDNA.IDNToASCII(src16, (int32) src16_length, dest16, dest16.length, ICU.IDNAOptions.DEFAULT, out error, ref status);
+            if (status == ICU.ErrorCode.INVALID_CHAR_FOUND) {
+                throw new InvalidJidError.INVALID_CHAR("Found invalid character");
+            } else if (status != ICU.ErrorCode.ZERO_ERROR) {
+                throw new InvalidJidError.UNKNOWN(@"Unknown error: $(status.errorName())");
+            } else if (dest16_length < 0) {
+                throw new InvalidJidError.UNKNOWN("Unknown error");
+            }
+        } catch (ConvertError e) {
+            throw new InvalidJidError.INVALID_CHAR(@"Conversion error: $(e.message)");
+        }
+    }
 
-        return new Jid.intern(jid, (owned) localpart, (owned) domainpart, (owned) resourcepart);
+    private static string? prepare(string? src, ICU.PrepType type) throws InvalidJidError {
+        if (src == null) return src;
+        try {
+            ICU.ErrorCode status = ICU.ErrorCode.ZERO_ERROR;
+            ICU.PrepProfile profile = ICU.PrepProfile.openByType(type, ref status);
+            long src16_length = 0;
+            string16 src16 = src.to_utf16(-1, null, out src16_length);
+            ICU.Char[] dest16 = new ICU.Char[src16_length * 2];
+            ICU.ParseError error;
+            long dest16_length = profile.prepare((ICU.Char*) src16, (int32) src16_length, dest16, dest16.length, ICU.PrepOptions.ALLOW_UNASSIGNED, out error, ref status);
+            if (status == ICU.ErrorCode.INVALID_CHAR_FOUND) {
+                throw new InvalidJidError.INVALID_CHAR("Found invalid character");
+            } else if (status != ICU.ErrorCode.ZERO_ERROR) {
+                throw new InvalidJidError.UNKNOWN(@"Unknown error: $(status.errorName())");
+            } else if (dest16_length < 0) {
+                throw new InvalidJidError.UNKNOWN("Unknown error");
+            }
+            return ((string16) dest16).to_utf8(dest16_length, null, null);
+        } catch (ConvertError e) {
+            throw new InvalidJidError.INVALID_CHAR(@"Conversion error: $(e.message)");
+        }
     }
 
-    public Jid with_resource(string? resourcepart) {
+    public Jid with_resource(string? resourcepart) throws InvalidJidError {
         return new Jid.components(localpart, domainpart, resourcepart);
     }
 
@@ -68,7 +134,7 @@ public class Jid {
     }
 
     public bool is_bare() {
-        return localpart != null && resourcepart == null;
+        return resourcepart == null;
     }
 
     public bool is_full() {
@@ -76,6 +142,17 @@ public class Jid {
     }
 
     public string to_string() {
+        if (jid == null) {
+            if (localpart != null && resourcepart != null) {
+                jid = @"$localpart@$domainpart/$resourcepart";
+            } else if (localpart != null) {
+                jid = @"$localpart@$domainpart";
+            } else if (resourcepart != null) {
+                jid = @"$domainpart/$resourcepart";
+            } else {
+                jid = domainpart;
+            }
+        }
         return jid;
     }
 
@@ -88,11 +165,11 @@ public class Jid {
     }
 
     public static new bool equals_bare_func(Jid jid1, Jid jid2) {
-        return jid1.bare_jid.to_string() == jid2.bare_jid.to_string();
+        return jid1.localpart == jid2.localpart && jid1.domainpart == jid2.domainpart;
     }
 
     public static bool equals_func(Jid jid1, Jid jid2) {
-        return jid1.to_string() == jid2.to_string();
+        return equals_bare_func(jid1, jid2) && jid1.resourcepart == jid2.resourcepart;
     }
 
     public static new uint hash_bare_func(Jid jid) {
@@ -104,4 +181,12 @@ public class Jid {
     }
 }
 
+public errordomain InvalidJidError {
+    EMPTY_DOMAIN,
+    EMPTY_RESOURCE,
+    EMPTY_LOCAL,
+    INVALID_CHAR,
+    UNKNOWN
+}
+
 }
diff --git a/xmpp-vala/src/module/roster/item.vala b/xmpp-vala/src/module/roster/item.vala
index 2fbf03ef..78974a35 100644
--- a/xmpp-vala/src/module/roster/item.vala
+++ b/xmpp-vala/src/module/roster/item.vala
@@ -17,8 +17,15 @@ public class Item {
     public StanzaNode stanza_node;
 
     private Jid jid_;
-    public Jid jid {
-        get { return jid_ ?? (jid_ = Jid.parse(stanza_node.get_attribute(NODE_JID))); }
+    public Jid? jid {
+        get {
+            try {
+                return jid_ ?? (jid_ = new Jid(stanza_node.get_attribute(NODE_JID)));
+            } catch (InvalidJidError e) {
+                warning("Ignoring invalid Jid in roster entry: %s", e.message);
+                return null;
+            }
+        }
         set { stanza_node.set_attribute(NODE_JID, value.to_string()); }
     }
 
diff --git a/xmpp-vala/src/module/stanza.vala b/xmpp-vala/src/module/stanza.vala
index abdc33e9..f4e40f84 100644
--- a/xmpp-vala/src/module/stanza.vala
+++ b/xmpp-vala/src/module/stanza.vala
@@ -18,7 +18,13 @@ public class Stanza : Object {
             string? from_attribute = stanza.get_attribute(ATTRIBUTE_FROM);
             // "when a client receives a stanza that does not include a 'from' attribute, it MUST assume that the stanza
             // is from the user's account on the server." (RFC6120 8.1.2.1)
-            if (from_attribute != null) return from_ = Jid.parse(from_attribute);
+            if (from_attribute != null) {
+                try {
+                    return from_ = new Jid(from_attribute);
+                } catch (InvalidJidError e) {
+                    warning("Ignoring invalid from Jid: %s", e.message);
+                }
+            }
             if (my_jid != null) {
                 return my_jid.bare_jid;
             }
@@ -37,7 +43,12 @@ public class Stanza : Object {
             string? to_attribute = stanza.get_attribute(ATTRIBUTE_TO);
             // "if the stanza does not include a 'to' address then the client MUST treat it as if the 'to' address were
             // included with a value of the client's full JID." (RFC6120 8.1.1.1)
-            return to_attribute == null ? my_jid : to_ = Jid.parse(to_attribute);
+            try {
+                return to_attribute == null ? my_jid : to_ = new Jid(to_attribute);
+            } catch (InvalidJidError e) {
+                warning("Ignoring invalid to Jid: %s", e.message);
+            }
+            return my_jid;
         }
         set { stanza.set_attribute(ATTRIBUTE_TO, value.to_string()); }
     }
diff --git a/xmpp-vala/src/module/xep/0030_service_discovery/items_result.vala b/xmpp-vala/src/module/xep/0030_service_discovery/items_result.vala
index 16a9f5ec..233a0c06 100644
--- a/xmpp-vala/src/module/xep/0030_service_discovery/items_result.vala
+++ b/xmpp-vala/src/module/xep/0030_service_discovery/items_result.vala
@@ -9,9 +9,13 @@ public class ItemsResult {
         owned get {
             ArrayList<Item> ret = new ArrayList<Item>();
             foreach (StanzaNode feature_node in iq.stanza.get_subnode("query", NS_URI_ITEMS).get_subnodes("item", NS_URI_ITEMS)) {
-                ret.add(new Item(Jid.parse(feature_node.get_attribute("jid", NS_URI_ITEMS)),
-                                        feature_node.get_attribute("name", NS_URI_ITEMS),
-                                        feature_node.get_attribute("node", NS_URI_ITEMS)));
+                try {
+                    ret.add(new Item(new Jid(feature_node.get_attribute("jid", NS_URI_ITEMS)),
+                                feature_node.get_attribute("name", NS_URI_ITEMS),
+                                feature_node.get_attribute("node", NS_URI_ITEMS)));
+                } catch (InvalidJidError e) {
+                    warning("Ignoring service at invalid Jid: %s", e.message);
+                }
             }
             return ret;
         }
diff --git a/xmpp-vala/src/module/xep/0045_muc/module.vala b/xmpp-vala/src/module/xep/0045_muc/module.vala
index 59d61f3d..ec10d500 100644
--- a/xmpp-vala/src/module/xep/0045_muc/module.vala
+++ b/xmpp-vala/src/module/xep/0045_muc/module.vala
@@ -82,41 +82,50 @@ public class Module : XmppStreamModule {
     }
 
     public async JoinResult? enter(XmppStream stream, Jid bare_jid, string nick, string? password, DateTime? history_since) {
-        Presence.Stanza presence = new Presence.Stanza();
-        presence.to = bare_jid.with_resource(nick);
-        StanzaNode x_node = new StanzaNode.build("x", NS_URI).add_self_xmlns();
-        if (password != null) {
-            x_node.put_node(new StanzaNode.build("password", NS_URI).put_node(new StanzaNode.text(password)));
-        }
-        if (history_since != null) {
-            StanzaNode history_node = new StanzaNode.build("history", NS_URI);
-            history_node.set_attribute("since", DateTimeProfiles.to_datetime(history_since));
-            x_node.put_node(history_node);
-        }
-        presence.stanza.put_node(x_node);
+        try {
+            Presence.Stanza presence = new Presence.Stanza();
+            presence.to = bare_jid.with_resource(nick);
 
-        stream.get_flag(Flag.IDENTITY).start_muc_enter(bare_jid, presence.id);
+            StanzaNode x_node = new StanzaNode.build("x", NS_URI).add_self_xmlns();
+            if (password != null) {
+                x_node.put_node(new StanzaNode.build("password", NS_URI).put_node(new StanzaNode.text(password)));
+            }
+            if (history_since != null) {
+                StanzaNode history_node = new StanzaNode.build("history", NS_URI);
+                history_node.set_attribute("since", DateTimeProfiles.to_datetime(history_since));
+                x_node.put_node(history_node);
+            }
+            presence.stanza.put_node(x_node);
 
-        query_room_info(stream, bare_jid);
-        stream.get_module(Presence.Module.IDENTITY).send_presence(stream, presence);
+            stream.get_flag(Flag.IDENTITY).start_muc_enter(bare_jid, presence.id);
 
-        var promise = new Promise<JoinResult?>();
-        stream.get_flag(Flag.IDENTITY).enter_futures[bare_jid] = promise;
-        try {
-            JoinResult? enter_result = yield promise.future.wait_async();
-            stream.get_flag(Flag.IDENTITY).enter_futures.unset(bare_jid);
-            return enter_result;
-        } catch (Gee.FutureError e) {
-            return null;
+            query_room_info(stream, bare_jid);
+            stream.get_module(Presence.Module.IDENTITY).send_presence(stream, presence);
+
+            var promise = new Promise<JoinResult?>();
+            stream.get_flag(Flag.IDENTITY).enter_futures[bare_jid] = promise;
+            try {
+                JoinResult? enter_result = yield promise.future.wait_async();
+                stream.get_flag(Flag.IDENTITY).enter_futures.unset(bare_jid);
+                return enter_result;
+            } catch (Gee.FutureError e) {
+                return null;
+            }
+        } catch (InvalidJidError e) {
+            return new JoinResult() { muc_error = MucEnterError.NICK_CONFLICT };
         }
     }
 
     public void exit(XmppStream stream, Jid jid) {
-        string nick = stream.get_flag(Flag.IDENTITY).get_muc_nick(jid);
-        Presence.Stanza presence = new Presence.Stanza();
-        presence.to = jid.with_resource(nick);
-        presence.type_ = Presence.Stanza.TYPE_UNAVAILABLE;
-        stream.get_module(Presence.Module.IDENTITY).send_presence(stream, presence);
+        try {
+            string nick = stream.get_flag(Flag.IDENTITY).get_muc_nick(jid);
+            Presence.Stanza presence = new Presence.Stanza();
+            presence.to = jid.with_resource(nick);
+            presence.type_ = Presence.Stanza.TYPE_UNAVAILABLE;
+            stream.get_module(Presence.Module.IDENTITY).send_presence(stream, presence);
+        } catch (InvalidJidError e) {
+            warning("Tried to leave room with invalid nick: %s", e.message);
+        }
     }
 
     public void change_subject(XmppStream stream, Jid jid, string subject) {
@@ -128,9 +137,14 @@ public class Module : XmppStreamModule {
     }
 
     public void change_nick(XmppStream stream, Jid jid, string new_nick) {
-        Presence.Stanza presence = new Presence.Stanza();
-        presence.to = jid.with_resource(new_nick);
-        stream.get_module(Presence.Module.IDENTITY).send_presence(stream, presence);
+        // TODO: Return if successful
+        try {
+            Presence.Stanza presence = new Presence.Stanza();
+            presence.to = jid.with_resource(new_nick);
+            stream.get_module(Presence.Module.IDENTITY).send_presence(stream, presence);
+        } catch (InvalidJidError e) {
+            warning("Tried to change nick to invalid nick: %s", e.message);
+        }
     }
 
     public void invite(XmppStream stream, Jid to_muc, Jid jid) {
@@ -148,20 +162,25 @@ public class Module : XmppStreamModule {
 
     /* XEP 0046: "A user cannot be kicked by a moderator with a lower affiliation." (XEP 0045 8.2) */
     public bool kick_possible(XmppStream stream, Jid occupant) {
-        Jid muc_jid = occupant.bare_jid;
-        Flag flag = stream.get_flag(Flag.IDENTITY);
-        string own_nick = flag.get_muc_nick(muc_jid);
-        Affiliation my_affiliation = flag.get_affiliation(muc_jid, muc_jid.with_resource(own_nick));
-        Affiliation other_affiliation = flag.get_affiliation(muc_jid, occupant);
-        switch (my_affiliation) {
-            case Affiliation.MEMBER:
-                if (other_affiliation == Affiliation.ADMIN || other_affiliation == Affiliation.OWNER) return false;
-                break;
-            case Affiliation.ADMIN:
-                if (other_affiliation == Affiliation.OWNER) return false;
-                break;
+        try {
+            Jid muc_jid = occupant.bare_jid;
+            Flag flag = stream.get_flag(Flag.IDENTITY);
+            string own_nick = flag.get_muc_nick(muc_jid);
+            Affiliation my_affiliation = flag.get_affiliation(muc_jid, muc_jid.with_resource(own_nick));
+            Affiliation other_affiliation = flag.get_affiliation(muc_jid, occupant);
+            switch (my_affiliation) {
+                case Affiliation.MEMBER:
+                    if (other_affiliation == Affiliation.ADMIN || other_affiliation == Affiliation.OWNER) return false;
+                    break;
+                case Affiliation.ADMIN:
+                    if (other_affiliation == Affiliation.OWNER) return false;
+                    break;
+            }
+            return true;
+        } catch (InvalidJidError e) {
+            warning("Tried to kick with invalid nick: %s", e.message);
+            return false;
         }
-        return true;
     }
 
     public void change_role(XmppStream stream, Jid jid, string nick, string new_role) {
@@ -314,12 +333,16 @@ public class Module : XmppStreamModule {
                 }
                 string? jid_ = x_node.get_deep_attribute("item", "jid");
                 if (jid_ != null) {
-                    Jid? jid = Jid.parse(jid_);
-                    flag.set_real_jid(presence.from, jid);
-                    if (affiliation != null) {
-                        stream.get_flag(Flag.IDENTITY).set_offline_member(presence.from, jid, affiliation);
+                    try {
+                        Jid jid = new Jid(jid_);
+                        flag.set_real_jid(presence.from, jid);
+                        if (affiliation != null) {
+                            stream.get_flag(Flag.IDENTITY).set_offline_member(presence.from, jid, affiliation);
+                        }
+                        received_occupant_jid(stream, presence.from, jid);
+                    } catch (InvalidJidError e) {
+                        warning("Received invalid occupant jid: %s", e.message);
                     }
-                    received_occupant_jid(stream, presence.from, jid);
                 }
                 string? role_str = x_node.get_deep_attribute("item", "role");
                 if (role_str != null) {
@@ -414,12 +437,17 @@ public class Module : XmppStreamModule {
             Gee.List<StanzaNode> item_nodes = query_node.get_subnodes("item", NS_URI_ADMIN);
             Gee.List<Jid> ret_jids = new ArrayList<Jid>(Jid.equals_func);
             foreach (StanzaNode item in item_nodes) {
-                Jid? jid_ = Jid.parse(item.get_attribute("jid"));
+                string jid__ = item.get_attribute("jid");
                 string? affiliation_ = item.get_attribute("affiliation");
-                if (jid_ != null && affiliation_ != null) {
-                    stream.get_flag(Flag.IDENTITY).set_offline_member(iq.from, jid_, parse_affiliation(affiliation_));
-                    ret_jids.add(jid_);
-                    received_occupant_jid(stream, iq.from, jid_);
+                if (jid__ != null && affiliation_ != null) {
+                    try {
+                        Jid jid_ = new Jid(jid__);
+                        stream.get_flag(Flag.IDENTITY).set_offline_member(iq.from, jid_, parse_affiliation(affiliation_));
+                        ret_jids.add(jid_);
+                        received_occupant_jid(stream, iq.from, jid_);
+                    } catch (InvalidJidError e) {
+                        warning("Received invalid occupant jid: %s", e.message);
+                    }
                 }
             }
             if (listener != null) listener(stream, ret_jids);
@@ -489,13 +517,19 @@ public class ReceivedPipelineListener : StanzaListener<MessageStanza> {
                 StanzaNode? password_node = x_node.get_subnode("password", NS_URI_USER);
                 if (password_node != null) password = password_node.get_string_content();
                 if (invite_node != null) {
-                    string? from_jid = invite_node.get_attribute("from");
+                    Jid? from_jid = null;
+                    try {
+                        string from = invite_node.get_attribute("from");
+                        if (from != null) from_jid = new Jid(from);
+                    } catch (InvalidJidError e) {
+                        warning("Received invite from invalid jid: %s", e.message);
+                    }
                     if (from_jid != null) {
                         StanzaNode? reason_node = invite_node.get_subnode("reason", NS_URI_USER);
                         string? reason = null;
                         if (reason_node != null) reason = reason_node.get_string_content();
                         bool is_mam_message = Xep.MessageArchiveManagement.MessageFlag.get_flag(message) != null; // TODO
-                        if (!is_mam_message) outer.invite_received(stream, message.from, new Jid(from_jid), password, reason);
+                        if (!is_mam_message) outer.invite_received(stream, message.from, from_jid, password, reason);
                         return true;
                     }
                 }
diff --git a/xmpp-vala/src/module/xep/0048_conference.vala b/xmpp-vala/src/module/xep/0048_conference.vala
index d78a2685..fdc26152 100644
--- a/xmpp-vala/src/module/xep/0048_conference.vala
+++ b/xmpp-vala/src/module/xep/0048_conference.vala
@@ -20,8 +20,14 @@ public class Bookmarks1Conference : Conference {
     }
 
     private Jid jid_;
-    public override Jid jid {
-    get { return jid_ ?? (jid_ = Jid.parse(stanza_node.get_attribute(ATTRIBUTE_JID))); }
+    public override Jid? jid {
+    get {
+        try {
+            return jid_ ?? (jid_ = new Jid(stanza_node.get_attribute(ATTRIBUTE_JID)));
+        } catch (InvalidJidError e) {
+            return null;
+        }
+    }
     set { stanza_node.set_attribute(ATTRIBUTE_JID, value.to_string()); }
     }
 
diff --git a/xmpp-vala/src/module/xep/0065_socks5_bytestreams.vala b/xmpp-vala/src/module/xep/0065_socks5_bytestreams.vala
index 1890aac3..a1be00d4 100644
--- a/xmpp-vala/src/module/xep/0065_socks5_bytestreams.vala
+++ b/xmpp-vala/src/module/xep/0065_socks5_bytestreams.vala
@@ -52,7 +52,11 @@ public class Module : XmppStreamModule, Iq.Handler {
                                 }
                                 string? host = stream_host.get_attribute("host");
                                 string? jid_str = stream_host.get_attribute("jid");
-                                Jid? jid = jid_str != null ? Jid.parse(jid_str) : null;
+                                Jid? jid = null;
+                                try {
+                                    jid = jid_str != null ? new Jid(jid_str) : null;
+                                } catch (InvalidJidError ignored) {
+                                }
                                 int port = stream_host.get_attribute_int("port");
                                 if (host == null || jid == null || port <= 0 || port > 65535) {
                                     return;
diff --git a/xmpp-vala/src/module/xep/0166_jingle.vala b/xmpp-vala/src/module/xep/0166_jingle.vala
index 7fc6c929..ca368f00 100644
--- a/xmpp-vala/src/module/xep/0166_jingle.vala
+++ b/xmpp-vala/src/module/xep/0166_jingle.vala
@@ -572,13 +572,15 @@ public class Session {
     }
     void handle_session_accept(XmppStream stream, ContentNode content, StanzaNode jingle, Iq.Stanza iq) throws IqError {
         string? responder_str = jingle.get_attribute("responder");
-        Jid responder;
+        Jid responder = iq.from;
         if (responder_str != null) {
-            responder = Jid.parse(responder_str) ?? iq.from;
-        } else {
-            responder = iq.from; // TODO(hrxi): and above, can we assume iq.from != null
-            // TODO(hrxi): more sanity checking, perhaps replace who we're talking to
+            try {
+                responder = new Jid(responder_str);
+            } catch (InvalidJidError e) {
+                warning("Received invalid session accept: %s", e.message);
+            }
         }
+        // TODO(hrxi): more sanity checking, perhaps replace who we're talking to
         if (!responder.is_full()) {
             throw new IqError.BAD_REQUEST("invalid responder JID");
         }
diff --git a/xmpp-vala/src/module/xep/0260_jingle_socks5_bytestreams.vala b/xmpp-vala/src/module/xep/0260_jingle_socks5_bytestreams.vala
index 991ea141..c6556eb7 100644
--- a/xmpp-vala/src/module/xep/0260_jingle_socks5_bytestreams.vala
+++ b/xmpp-vala/src/module/xep/0260_jingle_socks5_bytestreams.vala
@@ -116,7 +116,11 @@ public class Candidate : Socks5Bytestreams.Proxy {
         string? cid = candidate.get_attribute("cid");
         string? host = candidate.get_attribute("host");
         string? jid_str = candidate.get_attribute("jid");
-        Jid? jid = jid_str != null ? Jid.parse(jid_str) : null;
+        Jid? jid = null;
+        try {
+            jid = new Jid(jid_str);
+        } catch (InvalidJidError ignored) {
+        }
         int port = candidate.get_attribute("port") != null ? candidate.get_attribute_int("port") : 1080;
         int priority = candidate.get_attribute_int("priority");
         string? type_str = candidate.get_attribute("type");
diff --git a/xmpp-vala/src/module/xep/0402_bookmarks2.vala b/xmpp-vala/src/module/xep/0402_bookmarks2.vala
index 15386398..50c52ac2 100644
--- a/xmpp-vala/src/module/xep/0402_bookmarks2.vala
+++ b/xmpp-vala/src/module/xep/0402_bookmarks2.vala
@@ -66,19 +66,28 @@ public class Module : BookmarksProvider, XmppStreamModule {
     }
 
     private void on_pupsub_retract(XmppStream stream, Jid jid, string id) {
-        Jid jid_parsed = Jid.parse(id);
-        Flag? flag = stream.get_flag(Flag.IDENTITY);
-        if (flag != null) {
-            flag.conferences.unset(jid_parsed);
+        try {
+            Jid jid_parsed = new Jid(id);
+            Flag? flag = stream.get_flag(Flag.IDENTITY);
+            if (flag != null) {
+                flag.conferences.unset(jid_parsed);
+            }
+            conference_removed(stream, jid_parsed);
+        } catch (InvalidJidError e) {
+            warning("Ignoring conference bookmark update with invalid Jid: %s", e.message);
         }
-        conference_removed(stream, jid_parsed);
     }
 
     private Conference? parse_item_node(StanzaNode conference_node, string id) {
         Conference conference = new Conference();
-        Jid? jid_parsed = Jid.parse(id);
-        if (jid_parsed == null || jid_parsed.resourcepart != null) return null;
-        conference.jid = jid_parsed;
+        try {
+            Jid jid_parsed = new Jid(id);
+            if (jid_parsed.resourcepart != null) return null;
+            conference.jid = jid_parsed;
+        } catch (InvalidJidError e) {
+            warning("Ignoring conference bookmark update with invalid Jid: %s", e.message);
+            return null;
+        }
 
         if (conference_node.name != "conference" || conference_node.ns_uri != NS_URI) return null;
 
diff --git a/xmpp-vala/tests/common.vala b/xmpp-vala/tests/common.vala
index b91bbf7c..c616d2e7 100644
--- a/xmpp-vala/tests/common.vala
+++ b/xmpp-vala/tests/common.vala
@@ -5,6 +5,7 @@ int main(string[] args) {
     GLib.Test.set_nonfatal_assertions();
     TestSuite.get_root().add_suite(new Xmpp.Test.StanzaTest().get_suite());
     TestSuite.get_root().add_suite(new Xmpp.Test.UtilTest().get_suite());
+    TestSuite.get_root().add_suite(new Xmpp.Test.JidTest().get_suite());
     return GLib.Test.run();
 }
 
@@ -74,6 +75,13 @@ bool fail_if_not_eq_str(string? left, string? right, string? reason = null) {
     return fail_if_not(!nullcheck && left == right, @"$(reason + ": " ?? "")$left != $right");
 }
 
+bool fail_if_eq_str(string? left, string? right, string? reason = null) {
+    bool nullcheck = (left == null && right != null) || (left != null && right == null);
+    if (left == null) left = "(null)";
+    if (right == null) right = "(null)";
+    return fail_if(!nullcheck && left == right, @"$(reason + ": " ?? "")$left == $right");
+}
+
 bool fail_if_not_eq_uint8_arr(uint8[] left, uint8[] right, string? reason = null) {
     if (fail_if_not_eq_int(left.length, right.length, @"$(reason + ": " ?? "")array length not equal")) return true;
     return fail_if_not_eq_str(Base64.encode(left), Base64.encode(right), reason);
diff --git a/xmpp-vala/tests/jid.vala b/xmpp-vala/tests/jid.vala
new file mode 100644
index 00000000..8928dc97
--- /dev/null
+++ b/xmpp-vala/tests/jid.vala
@@ -0,0 +1,93 @@
+namespace Xmpp.Test {
+
+class JidTest : Gee.TestCase {
+    public JidTest() {
+        base("Jid");
+
+        add_test("jid_valid_domain_only", () => { test_jid_valid("example.com"); });
+        add_test("jid_valid_bare", () => { test_jid_valid("test@example.com"); });
+        add_test("jid_valid_domain_with_resource", () => { test_jid_valid("example.com/test"); });
+        add_test("jid_valid_full", () => { test_jid_valid("test@example.com/test"); });
+
+        // Should those actually be valid?
+        add_test("jid_valid_emoji_local", () => { test_jid_valid("😅@example.com"); });
+        add_test("jid_valid_emoji_resource", () => { test_jid_valid("test@example.com/😅"); });
+
+        add_test("jid_invalid_emoji_domain", () => { test_jid_invalid("test@😅.com"); });
+        add_test("jid_invalid_bidi_local", () => { test_jid_invalid("te‏st@example.com"); });
+        add_test("jid_invalid_bidi_resource", () => { test_jid_invalid("test@example.com/te‏st"); });
+        add_test("jid_invalid_bidi_domain", () => { test_jid_invalid("test@exa‏mple.com"); });
+        add_test("jid_invalid_overlong_idn", () => { test_jid_invalid("test@ççççççççççççççççççççççççççççççççççççççççççççççççççççççççççççç.com"); });
+
+        add_test("jid_equal_end_domain", () => { test_jids_equal("test@example.com", "test@example.com."); });
+        add_test("jid_equal_case_domain", () => { test_jids_equal("test@example.com", "test@eXample.com"); });
+        add_test("jid_equal_norm_domain", () => { test_jids_equal("test@garçon.com", "test@garçon.com"); });
+        add_test("jid_equal_puny_domain", () => { test_jids_equal("test@garçon.com", "test@xn--garon-0ra.com"); });
+        add_test("jid_equal_case_local", () => { test_jids_equal("test@example.com", "tEst@example.com"); });
+        add_test("jid_equal_norm_local", () => { test_jids_equal("garçon@example.com", "garçon@example.com"); });
+        add_test("jid_equal_norm_resource", () => { test_jids_equal("test@example.com/garçon", "test@example.com/garçon"); });
+
+        add_test("jid_non_equal_case_resource", () => { test_jids_unequal("example.com/test", "example.com/tEst"); });
+
+        add_test("jid_to_string_end_domain", () => { test_jid_to_string("test@example.com.", "test@example.com"); });
+        add_test("jid_to_string_case_domain", () => { test_jid_to_string("test@eXample.com", "test@example.com"); });
+        add_test("jid_to_string_norm_domain", () => { test_jid_to_string("test@garçon.com", "test@garçon.com"); });
+        add_test("jid_to_string_puny_domain", () => { test_jid_to_string("test@xn--garon-0ra.com", "test@garçon.com"); });
+        add_test("jid_to_string_case_local", () => { test_jid_to_string("tEst@example.com", "test@example.com"); });
+        add_test("jid_to_string_norm_local", () => { test_jid_to_string("garçon@example.com", "garçon@example.com"); });
+        add_test("jid_to_string_case_resource", () => { test_jid_to_string("example.com/tEst", "example.com/tEst"); });
+        add_test("jid_to_string_norm_resource", () => { test_jid_to_string("test@example.com/garçon", "test@example.com/garçon"); });
+    }
+
+    private void test_jid_valid(string jid) {
+        try {
+            new Jid(jid);
+        } catch (Error e) {
+            fail_if_reached();
+        }
+    }
+
+    private void test_jid_invalid(string jid) {
+        try {
+            new Jid(jid);
+            fail_if_reached();
+        } catch (Error e) {
+//            try {
+//                fail_if_not_eq_str(Jid.parse(jid).to_string(), jid);
+//            } catch (Error e) {
+//                fail_if_reached();
+//            }
+        }
+    }
+
+    private void test_jids_equal(string jid1, string jid2) {
+        try {
+            var t1 = new Jid(jid1);
+            var t2 = new Jid(jid2);
+            fail_if_not_eq_str(t1.to_string(), t2.to_string());
+        } catch (Error e) {
+            fail_if_reached();
+        }
+    }
+
+    private void test_jid_to_string(string jid1, string jid2) {
+        try {
+            var t1 = new Jid(jid1);
+            fail_if_not_eq_str(t1.to_string(), jid2);
+        } catch (Error e) {
+            fail_if_reached();
+        }
+    }
+
+    private void test_jids_unequal(string jid1, string jid2) {
+        try {
+            var t1 = new Jid(jid1);
+            var t2 = new Jid(jid2);
+            fail_if_eq_str(t1.to_string(), t2.to_string());
+        } catch (Error e) {
+            fail_if_reached();
+        }
+    }
+}
+
+}
\ No newline at end of file
diff --git a/xmpp-vala/vapi/icu-uc.vapi b/xmpp-vala/vapi/icu-uc.vapi
new file mode 100644
index 00000000..14764440
--- /dev/null
+++ b/xmpp-vala/vapi/icu-uc.vapi
@@ -0,0 +1,56 @@
+namespace ICU {
+
+[CCode (cname = "UChar")]
+[IntegerType (rank = 5, min = 0, max = 65535)]
+struct Char {}
+
+[CCode (cname = "UErrorCode", cprefix = "U_", cheader_filename = "unicode/utypes.h")]
+enum ErrorCode {
+    ZERO_ERROR,
+    INVALID_CHAR_FOUND,
+    INDEX_OUTOFBOUNDS_ERROR,
+    BUFFER_OVERFLOW_ERROR,
+    UNASSIGNED_CODE_POINT_FOUND,
+    IDNA_STD3_ASCII_RULES_ERROR
+    ;
+    [CCode (cname = "u_errorName")]
+    public unowned string errorName();
+}
+
+[CCode (cname = "UErrorCode", cprefix = "U_", cheader_filename = "unicode/parseerr.h")]
+struct ParseError {}
+
+[CCode (cname = "UStringPrepProfile", cprefix = "usprep_", free_function = "usprep_close", cheader_filename = "unicode/usprep.h")]
+[Compact]
+class PrepProfile {
+    public static PrepProfile open(string path, string file_name, ref ErrorCode status);
+    public static PrepProfile openByType(PrepType type, ref ErrorCode status);
+    public int32 prepare(Char* src, int32 src_length, Char* dest, int32 dest_capacity, PrepOptions options, out ParseError parse_error, ref ErrorCode status);
+}
+[CCode (cname = "UStringPrepProfileType", cprefix = "USPREP_")]
+enum PrepType {
+    RFC3491_NAMEPREP,
+    RFC3920_NODEPREP,
+    RFC3920_RESOURCEPREP
+}
+[CCode (cname = "int32_t", cprefix = "USPREP_")]
+enum PrepOptions {
+    DEFAULT,
+    ALLOW_UNASSIGNED
+}
+
+[CCode (cname = "UIDNA", cprefix = "uidna_", free_function = "uidna_close", cheader_filename = "unicode/uidna.h")]
+[Compact]
+class IDNA {
+    public static int32 IDNToUnicode(Char* src, int32 src_length, Char* dest, int32 dest_capacity, IDNAOptions options, out ParseError parse_error, ref ErrorCode status);
+    public static int32 IDNToASCII(Char* src, int32 src_length, Char* dest, int32 dest_capacity, IDNAOptions options, out ParseError parse_error, ref ErrorCode status);
+}
+
+[CCode (cname = "uint32_t", cprefix = "UIDNA_")]
+enum IDNAOptions {
+    DEFAULT,
+    ALLOW_UNASSIGNED,
+    USE_STD3_RULES
+}
+
+}