aboutsummaryrefslogtreecommitdiff
path: root/plugins/omemo/src/trust_manager.vala
blob: 2631513b91f19fabb266124138cbc6870fad451e (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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
using Dino.Entities;
using Gee;
using Xmpp;
using Signal;
using Qlite;

namespace Dino.Plugins.Omemo {

public class TrustManager {

    private StreamInteractor stream_interactor;
    private Database db;
    private ReceivedMessageListener received_message_listener;

    public TrustManager(StreamInteractor stream_interactor, Database db) {
        this.stream_interactor = stream_interactor;
        this.db = db;

        received_message_listener = new ReceivedMessageListener(stream_interactor, db);
        stream_interactor.get_module(MessageProcessor.IDENTITY).received_pipeline.connect(received_message_listener);
    }

    public void set_blind_trust(Account account, Jid jid, bool blind_trust) {
        db.trust.update()
            .with(db.trust.identity_id, "=", account.id)
            .with(db.trust.address_name, "=", jid.bare_jid.to_string())
            .set(db.trust.blind_trust, blind_trust).perform();
    }

    public void set_device_trust(Account account, Jid jid, int device_id, Database.IdentityMetaTable.TrustLevel trust_level) {
        db.identity_meta.update()
            .with(db.identity_meta.identity_id, "=", account.id)
            .with(db.identity_meta.address_name, "=", jid.bare_jid.to_string())
            .with(db.identity_meta.device_id, "=", device_id)
            .set(db.identity_meta.trust_level, trust_level).perform();
    }

    private StanzaNode create_encrypted_key(uint8[] key, Address address, Store store) throws GLib.Error {
        SessionCipher cipher = store.create_session_cipher(address);
        CiphertextMessage device_key = cipher.encrypt(key);
        StanzaNode key_node = new StanzaNode.build("key", NS_URI)
            .put_attribute("rid", address.device_id.to_string())
            .put_node(new StanzaNode.text(Base64.encode(device_key.serialized)));
        if (device_key.type == CiphertextType.PREKEY) key_node.put_attribute("prekey", "true");
        return key_node;
    }

    public EncryptState encrypt(MessageStanza message, Jid self_jid, Gee.List<Jid> recipients, XmppStream stream, Account account) {
        EncryptState status = new EncryptState();
        if (!Plugin.ensure_context()) return status;
        if (message.to == null) return status;

        StreamModule module = stream.get_module(StreamModule.IDENTITY);

        try {
            //Check we have the bundles and device lists needed to send the message
            if (!is_known_address(account, self_jid)) return status;
            status.own_list = true;
            status.own_devices = get_trusted_devices(account, self_jid).size;
            status.other_waiting_lists = 0;
            status.other_devices = 0;
            foreach (Jid recipient in recipients) {
                if (!is_known_address(account, recipient)) {
                    status.other_waiting_lists++;
                }
                if (status.other_waiting_lists > 0) return status;
                status.other_devices += get_trusted_devices(account, recipient).size;
            }
            if (status.own_devices == 0 || status.other_devices == 0) return status;

            //Create a key and use it to encrypt the message
            uint8[] key = new uint8[16];
            Plugin.get_context().randomize(key);
            uint8[] iv = new uint8[16];
            Plugin.get_context().randomize(iv);

            uint8[] ciphertext = aes_encrypt(Cipher.AES_GCM_NOPADDING, key, iv, message.body.data);

            StanzaNode header;
            StanzaNode encrypted = new StanzaNode.build("encrypted", NS_URI).add_self_xmlns()
                    .put_node(header = new StanzaNode.build("header", NS_URI)
                        .put_attribute("sid", module.store.local_registration_id.to_string())
                        .put_node(new StanzaNode.build("iv", NS_URI)
                            .put_node(new StanzaNode.text(Base64.encode(iv)))))
                    .put_node(new StanzaNode.build("payload", NS_URI)
                        .put_node(new StanzaNode.text(Base64.encode(ciphertext))));

            //Encrypt the key for each recipient's device individually
            Address address = new Address(message.to.bare_jid.to_string(), 0);
            foreach (Jid recipient in recipients) {
                foreach(int32 device_id in get_trusted_devices(account, recipient)) {
                    if (module.is_ignored_device(recipient, device_id)) {
                        status.other_lost++;
                        continue;
                    }
                    try {
                        address.name = recipient.bare_jid.to_string();
                        address.device_id = (int) device_id;
                        StanzaNode key_node = create_encrypted_key(key, address, module.store);
                        header.put_node(key_node);
                        status.other_success++;
                    } catch (Error e) {
                        if (e.code == ErrorCode.UNKNOWN) status.other_unknown++;
                        else status.other_failure++;
                    }
                }
            }
            address.name = self_jid.bare_jid.to_string();
            foreach(int32 device_id in get_trusted_devices(account, self_jid)) {
                if (module.is_ignored_device(self_jid, device_id)) {
                    status.own_lost++;
                    continue;
                }
                if (device_id != module.store.local_registration_id) {
                    address.device_id = (int) device_id;
                    try {
                        StanzaNode key_node = create_encrypted_key(key, address, module.store);
                        header.put_node(key_node);
                        status.own_success++;
                    } catch (Error e) {
                        if (e.code == ErrorCode.UNKNOWN) status.own_unknown++;
                        else status.own_failure++;
                    }
                }
            }

            message.stanza.put_node(encrypted);
            Xep.ExplicitEncryption.add_encryption_tag_to_message(message, NS_URI, "OMEMO");
            message.body = "[This message is OMEMO encrypted]";
            status.encrypted = true;
        } catch (Error e) {
            if (Plugin.DEBUG) print(@"OMEMO: Signal error while encrypting message: $(e.message)\n");
        }
        return status;
    }

    public bool is_known_address(Account account, Jid jid) {
        return db.identity_meta.with_address(account.id, jid.to_string()).count() > 0;
    }

    public Gee.List<int32> get_trusted_devices(Account account, Jid jid) {
        Gee.List<int32> devices = new ArrayList<int32>();
        foreach (Row device in db.identity_meta.get_trusted_devices(account.id, jid.bare_jid.to_string())) {
            if(device[db.identity_meta.trust_level] != Database.IdentityMetaTable.TrustLevel.UNKNOWN || device[db.identity_meta.identity_key_public_base64] == null)
                devices.add(device[db.identity_meta.device_id]);
        }
        return devices;
    }

    private class ReceivedMessageListener : MessageListener {
        public string[] after_actions_const = new string[]{ };
        public override string action_group { get { return "DECRYPT"; } }
        public override string[] after_actions { get { return after_actions_const; } }

        private StreamInteractor stream_interactor;
        private Database db;

        public ReceivedMessageListener(StreamInteractor stream_interactor, Database db) {
            this.stream_interactor = stream_interactor;
            this.db = db;
        }

        public override async bool run(Entities.Message message, Xmpp.MessageStanza stanza, Conversation conversation) {
            MessageFlag? flag = MessageFlag.get_flag(stanza);
            if(flag != null && ((!)flag).decrypted) {
                StanzaNode header = stanza.stanza.get_subnode("encrypted", "eu.siacs.conversations.axolotl").get_subnode("header");
                Jid jid = message.from;
                if(conversation.type_ == Conversation.Type.GROUPCHAT) {
                    jid = stream_interactor.get_module(MucManager.IDENTITY).get_real_jid(jid, conversation.account);
                }
                Database.IdentityMetaTable.TrustLevel trust_level = (Database.IdentityMetaTable.TrustLevel) db.identity_meta.get_device(conversation.account.id, jid.bare_jid.to_string(), header.get_attribute_int("sid"))[db.identity_meta.trust_level];
                if (trust_level == Database.IdentityMetaTable.TrustLevel.UNTRUSTED) {
                    message.body = _("OMEMO message from a rejected device");
                    message.marked = Message.Marked.WONTSEND;
                }
                if (trust_level == Database.IdentityMetaTable.TrustLevel.UNKNOWN) {
                    message.body = _("OMEMO message from an unknown device: ")+message.body;
                    message.marked = Message.Marked.WONTSEND;
                }
            }
            return false;
        }
    }
}

}