Allow certificates from unknown CAs from .onion domains

It's barely possible for .onion servers to provide a non-self-signed cert. But that's fine because encryption is provided independently though TOR.

see #958

libdino/src/service/connection_manager.vala

@@ -196,7 +196,9 @@ public class ConnectionManager : Object {
             connection_directly_retry[account] = false;
 
             change_connection_state(account, ConnectionState.CONNECTING);
-            stream_result = yield Xmpp.establish_stream(account.bare_jid, module_manager.get_modules(account, resource), log_options);
+            stream_result = yield Xmpp.establish_stream(account.bare_jid, module_manager.get_modules(account, resource), log_options,
+                    (_, peer_cert, errors) => { return on_invalid_certificate(account.domainpart, peer_cert, errors); }
+            );
             connections[account].stream = stream_result.stream;
 
             connection_ongoing[account] = false;
@@ -368,6 +370,16 @@ public class ConnectionManager : Object {
         connection_errors[account] = error;
         connection_error(account, error);
     }
+
+    public static bool on_invalid_certificate(string domain, TlsCertificate peer_cert, TlsCertificateFlags errors) {
+        if (domain.has_suffix(".onion") && errors == TlsCertificateFlags.UNKNOWN_CA) {
+            // It's barely possible for .onion servers to provide a non-self-signed cert.
+            // But that's fine because encryption is provided independently though TOR.
+            warning("Accepting TLS certificate from unknown CA from .onion address %s", domain);
+            return true;
+        }
+        return false;
+    }
 }
 
 }

libdino/src/service/registration.vala

@@ -29,7 +29,9 @@ public class Register : StreamInteractionModule, Object{
         list.add(new Iq.Module());
         list.add(new Sasl.Module(account.bare_jid.to_string(), account.password));
 
-        XmppStreamResult stream_result = yield Xmpp.establish_stream(account.bare_jid.domain_jid, list, Application.print_xmpp);
+        XmppStreamResult stream_result = yield Xmpp.establish_stream(account.bare_jid.domain_jid, list, Application.print_xmpp,
+                (_, peer_cert, errors) => { return ConnectionManager.on_invalid_certificate(account.domainpart, peer_cert, errors); }
+        );
 
         if (stream_result.stream == null) {
             if (stream_result.tls_errors != null) {
@@ -80,7 +82,9 @@ public class Register : StreamInteractionModule, Object{
         Gee.List<XmppStreamModule> list = new ArrayList<XmppStreamModule>();
         list.add(new Iq.Module());
 
-        XmppStreamResult stream_result = yield Xmpp.establish_stream(jid.domain_jid, list, Application.print_xmpp);
+        XmppStreamResult stream_result = yield Xmpp.establish_stream(jid.domain_jid, list, Application.print_xmpp,
+                (_, peer_cert, errors) => { return ConnectionManager.on_invalid_certificate(jid.domainpart, peer_cert, errors); }
+        );
 
         if (stream_result.stream == null) {
             if (stream_result.io_error != null) {
@@ -125,7 +129,9 @@ public class Register : StreamInteractionModule, Object{
         list.add(new Iq.Module());
         list.add(new Xep.InBandRegistration.Module());
 
-        XmppStreamResult stream_result = yield Xmpp.establish_stream(jid.domain_jid, list, Application.print_xmpp);
+        XmppStreamResult stream_result = yield Xmpp.establish_stream(jid.domain_jid, list, Application.print_xmpp,
+                (_, peer_cert, errors) => { return ConnectionManager.on_invalid_certificate(jid.domainpart, peer_cert, errors); }
+        );
 
         if (stream_result.stream == null) {
             return null;
@@ -169,7 +175,9 @@ public class Register : StreamInteractionModule, Object{
         list.add(new Iq.Module());
         list.add(new Xep.InBandRegistration.Module());
 
-        XmppStreamResult stream_result = yield Xmpp.establish_stream(jid.domain_jid, list, Application.print_xmpp);
+        XmppStreamResult stream_result = yield Xmpp.establish_stream(jid.domain_jid, list, Application.print_xmpp,
+                (_, peer_cert, errors) => { return ConnectionManager.on_invalid_certificate(jid.domainpart, peer_cert, errors); }
+        );
 
         if (stream_result.stream == null) {
             return null;

xmpp-vala/src/core/direct_tls_xmpp_stream.vala

@@ -2,11 +2,13 @@ public class Xmpp.DirectTlsXmppStream : TlsXmppStream {
 
     string host;
     uint16 port;
+    TlsXmppStream.OnInvalidCert on_invalid_cert_outer;
 
-    public DirectTlsXmppStream(Jid remote, string host, uint16 port) {
+    public DirectTlsXmppStream(Jid remote_name, string host, uint16 port, TlsXmppStream.OnInvalidCert on_invalid_cert) {
-        this.remote_name = remote;
+        base(remote_name);
         this.host = host;
         this.port = port;
+        this.on_invalid_cert_outer = on_invalid_cert;
     }
 
     public override async void connect() throws IOStreamError {
@@ -19,6 +21,7 @@ public class Xmpp.DirectTlsXmppStream : TlsXmppStream {
             tls_connection.set_advertised_protocols(new string[]{"xmpp-client"});
 #endif
             tls_connection.accept_certificate.connect(on_invalid_certificate);
+            tls_connection.accept_certificate.connect(on_invalid_cert_outer);
             reset_stream(tls_connection);
 
             yield setup();

xmpp-vala/src/core/io_xmpp_stream.vala

@@ -11,6 +11,10 @@ public abstract class Xmpp.IoXmppStream : XmppStream {
 
     internal WriteNodeFunc? write_obj = null;
 
+    protected IoXmppStream(Jid remote_name) {
+        base(remote_name);
+    }
+
     public override async void disconnect() throws IOStreamError, XmlError, IOError {
         disconnected = true;
         if (writer == null || reader == null || stream == null) {

xmpp-vala/src/core/starttls_xmpp_stream.vala

@@ -4,11 +4,13 @@ public class Xmpp.StartTlsXmppStream : TlsXmppStream {
 
     string host;
     uint16 port;
+    TlsXmppStream.OnInvalidCert on_invalid_cert_outer;
 
-    public StartTlsXmppStream(Jid remote, string host, uint16 port) {
+    public StartTlsXmppStream(Jid remote, string host, uint16 port, TlsXmppStream.OnInvalidCert on_invalid_cert) {
-        this.remote_name = remote;
+        base(remote);
         this.host = host;
         this.port = port;
+        this.on_invalid_cert_outer = on_invalid_cert;
     }
 
     public override async void connect() throws IOStreamError {
@@ -40,6 +42,7 @@ public class Xmpp.StartTlsXmppStream : TlsXmppStream {
                 reset_stream(conn);
 
                 conn.accept_certificate.connect(on_invalid_certificate);
+                conn.accept_certificate.connect(on_invalid_cert_outer);
             } catch (Error e) {
                 stderr.printf("Failed to start TLS: %s\n", e.message);
             }

xmpp-vala/src/core/stream_connect.vala

@@ -8,12 +8,12 @@ namespace Xmpp {
     }
 
     public class XmppStreamResult {
-        public XmppStream? stream { get; set; }
+        public TlsXmppStream? stream { get; set; }
         public TlsCertificateFlags? tls_errors { get; set; }
         public IOStreamError? io_error { get; set; }
     }
 
-    public async XmppStreamResult establish_stream(Jid bare_jid, Gee.List<XmppStreamModule> modules, string? log_options) {
+    public async XmppStreamResult establish_stream(Jid bare_jid, Gee.List<XmppStreamModule> modules, string? log_options, TlsXmppStream.OnInvalidCert on_invalid_cert) {
         Jid remote = bare_jid.domain_jid;
 
         //Lookup xmpp-client and xmpps-client SRV records
@@ -58,9 +58,9 @@ namespace Xmpp {
         foreach (SrvTargetInfo target in targets) {
             try {
                 if (target.service == "xmpp-client") {
-                    stream = new StartTlsXmppStream(remote, target.host, target.port);
+                    stream = new StartTlsXmppStream(remote, target.host, target.port, on_invalid_cert);
                 } else {
-                    stream = new DirectTlsXmppStream(remote, target.host, target.port);
+                    stream = new DirectTlsXmppStream(remote, target.host, target.port, on_invalid_cert);
                 }
                 stream.log = new XmppLog(bare_jid.to_string(), log_options);
 

xmpp-vala/src/core/tls_xmpp_stream.vala

@@ -2,6 +2,12 @@ public abstract class Xmpp.TlsXmppStream : IoXmppStream {
 
     public TlsCertificateFlags? errors;
 
+    public delegate bool OnInvalidCert(GLib.TlsConnection conn, GLib.TlsCertificate peer_cert, GLib.TlsCertificateFlags errors);
+
+    protected TlsXmppStream(Jid remote_name) {
+        base(remote_name);
+    }
+
     protected bool on_invalid_certificate(TlsCertificate peer_cert, TlsCertificateFlags errors) {
         this.errors = errors;
 
@@ -13,7 +19,7 @@ public abstract class Xmpp.TlsXmppStream : IoXmppStream {
                 error_str += @"$(f), ";
             }
         }
-        warning(@"Tls Certificate Errors: $(error_str)");
+        warning(@"[%p, %s] Tls Certificate Errors: %s", this, this.remote_name, error_str);
         return false;
     }
 }

xmpp-vala/src/core/xmpp_stream.vala

@@ -34,6 +34,10 @@ public abstract class Xmpp.XmppStream {
     protected bool setup_needed = false;
     protected bool disconnected = false;
 
+    protected XmppStream(Jid remote_name) {
+        this.remote_name = remote_name;
+    }
+
     public abstract async void connect() throws IOStreamError;
 
     public abstract async void disconnect() throws IOStreamError, XmlError, IOError;