aboutsummaryrefslogtreecommitdiff
path: root/xmpp-vala/src/module/xep/0115_entitiy_capabilities.vala
blob: b61a7f43b41929b63f45a1324d9ac9f6383dbaf6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
using Gee;

namespace Xmpp.Xep.EntityCapabilities {
    private const string NS_URI = "http://jabber.org/protocol/caps";

    public class Module : XmppStreamModule {
        public static ModuleIdentity<Module> IDENTITY = new ModuleIdentity<Module>(NS_URI, "0115_entity_capabilities");

        private string own_ver_hash;
        private Storage storage;
        private Regex sha1_base64_regex = /^[A-Za-z0-9+\/]{27}=$/;

        public Module(Storage storage) {
            this.storage = storage;
        }

        private string get_own_hash(XmppStream stream) {
            if (own_ver_hash == null) {
                own_ver_hash = compute_hash(stream.get_module(ServiceDiscovery.Module.IDENTITY).identities, stream.get_flag(ServiceDiscovery.Flag.IDENTITY).features, new ArrayList<DataForms.DataForm>());
            }
            return own_ver_hash;
        }

        public override void attach(XmppStream stream) {
            stream.get_module(Presence.Module.IDENTITY).pre_send_presence_stanza.connect(on_pre_send_presence_stanza);
            stream.get_module(Presence.Module.IDENTITY).received_presence.connect(on_received_presence);
            stream.get_module(ServiceDiscovery.Module.IDENTITY).add_feature(stream, NS_URI);
        }

        public override void detach(XmppStream stream) {
            stream.get_module(Presence.Module.IDENTITY).pre_send_presence_stanza.disconnect(on_pre_send_presence_stanza);
            stream.get_module(Presence.Module.IDENTITY).received_presence.disconnect(on_received_presence);
        }

        public override string get_ns() { return NS_URI; }
        public override string get_id() { return IDENTITY.id; }

        private void on_pre_send_presence_stanza(XmppStream stream, Presence.Stanza presence) {
            if (presence.type_ == Presence.Stanza.TYPE_AVAILABLE) {
                presence.stanza.put_node(new StanzaNode.build("c", NS_URI).add_self_xmlns()
                    .put_attribute("hash", "sha-1")
                    .put_attribute("node", "https://dino.im")
                    .put_attribute("ver", get_own_hash(stream)));
            }
        }

        private void on_received_presence(XmppStream stream, Presence.Stanza presence) {
            StanzaNode? c_node = presence.stanza.get_subnode("c", NS_URI);
            if (c_node != null) {
                string? ver_attribute = c_node.get_attribute("ver", NS_URI);
                if (ver_attribute == null || !sha1_base64_regex.match(ver_attribute)) return;
                Gee.List<string> capabilities = storage.get_features(ver_attribute);
                if (capabilities.size == 0) {
                    stream.get_module(ServiceDiscovery.Module.IDENTITY).request_info(stream, presence.from, (stream, query_result) => {
                        store_entity_result(stream, ver_attribute, query_result);
                    });
                } else {
                    stream.get_flag(ServiceDiscovery.Flag.IDENTITY).set_entity_features(presence.from, capabilities);
                }
            }
        }

        private void store_entity_result(XmppStream stream, string entity, ServiceDiscovery.InfoResult? query_result) {
            if (query_result == null) return;

            Gee.List<DataForms.DataForm> data_forms = new ArrayList<DataForms.DataForm>();
            foreach (StanzaNode node in query_result.iq.stanza.get_deep_subnodes(ServiceDiscovery.NS_URI_INFO + ":query", DataForms.NS_URI + ":x")) {
                data_forms.add(DataForms.DataForm.create_from_node(stream, node, (stream, node) => {}));
            }

            if (compute_hash(query_result.identities, query_result.features, data_forms) == entity) {
                storage.store_features(entity, query_result.features);
                stream.get_flag(ServiceDiscovery.Flag.IDENTITY).set_entity_features(query_result.iq.from, query_result.features);
            }
        }

        private static string compute_hash(Gee.List<ServiceDiscovery.Identity> identities, Gee.List<string> features, Gee.List<DataForms.DataForm> data_forms) {
            identities.sort(compare_identities);
            features.sort();

            string s = "";
            foreach (ServiceDiscovery.Identity identity in identities) {
                string s_identity = identity.category + "/" + identity.type_ + "//";
                if (identity.name != null) s_identity += identity.name;
                s_identity += "<";
                s += s_identity;
            }
            foreach (string feature in features) {
                s += feature + "<";
            }

            data_forms.sort(compare_data_forms);
            foreach (DataForms.DataForm data_form in data_forms) {
                if (data_form.form_type == null) {
                    // If [..] the FORM_TYPE field is not of type "hidden" or the form does not include a FORM_TYPE field, ignore the form but continue processing. (XEP-0115)
                    continue;
                }
                s += data_form.form_type + "<";

                data_form.fields.sort(compare_data_fields);
                foreach (DataForms.DataForm.Field field in data_form.fields) {
                    s += field.var + "<";
                    Gee.List<string> values = field.get_values();
                    values.sort();
                    foreach (string value in values) {
                        s += value + "<";
                    }
                }
            }

            Checksum c = new Checksum(ChecksumType.SHA1);
            c.update(s.data, -1);
            size_t size = 20;
            uint8[] buf = new uint8[size];
            c.get_digest(buf, ref size);

            return Base64.encode(buf);
        }

        private static int compare_identities(ServiceDiscovery.Identity a, ServiceDiscovery.Identity b) {
            int category_comp = a.category.collate(b.category);
            if (category_comp != 0) return category_comp;
            int type_comp = a.type_.collate(b.type_);
            if (type_comp != 0) return type_comp;
            // TODO lang
            return 0;
        }

        private static int compare_data_forms(DataForms.DataForm a, DataForms.DataForm b) {
            if (a.form_type != null && b.form_type != null) {
                return a.form_type.collate(b.form_type);
            }
            return 0;
        }

        private static int compare_data_fields(DataForms.DataForm.Field a, DataForms.DataForm.Field b) {
            if (a.var != null && b.var != null) {
                return a.var.collate(b.var);
            }
            return 0;
        }
    }

    public interface Storage : Object {
        public abstract void store_features(string entity, Gee.List<string> capabilities);
        public abstract Gee.List<string> get_features(string entity);
    }
}