anotherim-desktop/plugins/omemo/src/stream_module.vala

427 lines
20 KiB
Vala

using Gee;
using Xmpp;
using Xmpp.Core;
using Xmpp.Xep;
using Signal;
namespace Dino.Plugins.Omemo {
private const string NS_URI = "eu.siacs.conversations.axolotl";
private const string NODE_DEVICELIST = NS_URI + ".devicelist";
private const string NODE_BUNDLES = NS_URI + ".bundles";
private const string NODE_VERIFICATION = NS_URI + ".verification";
private const int NUM_KEYS_TO_PUBLISH = 100;
public class StreamModule : XmppStreamModule {
public static Core.ModuleIdentity<StreamModule> IDENTITY = new Core.ModuleIdentity<StreamModule>(NS_URI, "omemo_module");
private Store store;
private ConcurrentSet<string> active_bundle_requests = new ConcurrentSet<string>();
private ConcurrentSet<string> active_devicelist_requests = new ConcurrentSet<string>();
private Map<string, ArrayList<int32>> device_lists = new HashMap<string, ArrayList<int32>>();
private Map<string, ArrayList<int32>> ignored_devices = new HashMap<string, ArrayList<int32>>();
public signal void store_created(Store store);
public signal void device_list_loaded(string jid);
public signal void session_started(string jid, int device_id);
public signal void session_start_failed(string jid, int device_id);
public EncryptState encrypt(Message.Stanza message, string self_bare_jid) {
EncryptState status = new EncryptState();
if (!Plugin.ensure_context()) return status;
if (message.to == null) return status;
try {
string name = get_bare_jid((!)message.to);
if (!device_lists.has_key(self_bare_jid)) return status;
status.own_list = true;
status.own_devices = device_lists.get(self_bare_jid).size;
if (!device_lists.has_key(name)) return status;
status.other_list = true;
status.other_devices = device_lists.get(name).size;
if (status.own_devices == 0 || status.other_devices == 0) return status;
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", 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))));
Address address = new Address(name, 0);
foreach(int32 device_id in device_lists[name]) {
if (is_ignored_device(name, device_id)) {
status.other_lost++;
continue;
}
try {
address.device_id = (int) device_id;
StanzaNode key_node = create_encrypted_key(key, address);
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_bare_jid;
foreach(int32 device_id in device_lists[self_bare_jid]) {
if (is_ignored_device(self_bare_jid, device_id)) {
status.own_lost++;
continue;
}
if (device_id != store.local_registration_id) {
address.device_id = (int) device_id;
try {
StanzaNode key_node = create_encrypted_key(key, address);
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);
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;
}
private StanzaNode create_encrypted_key(uint8[] key, Address address) 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 override void attach(XmppStream stream) {
Message.Module.require(stream);
Pubsub.Module.require(stream);
if (!Plugin.ensure_context()) return;
this.store = Plugin.get_context().create_store();
store_created(store);
stream.get_module(Message.Module.IDENTITY).pre_received_message.connect(on_pre_received_message);
stream.get_module(Pubsub.Module.IDENTITY).add_filtered_notification(stream, NODE_DEVICELIST, (stream, jid, id, node) => on_devicelist(stream, jid, id, node));
}
private void on_pre_received_message(XmppStream stream, Message.Stanza message) {
StanzaNode? _encrypted = message.stanza.get_subnode("encrypted", NS_URI);
if (_encrypted == null || MessageFlag.get_flag(message) != null || message.from == null) return;
StanzaNode encrypted = (!)_encrypted;
if (!Plugin.ensure_context()) return;
MessageFlag flag = new MessageFlag();
message.add_flag(flag);
StanzaNode? _header = encrypted.get_subnode("header");
if (_header == null) return;
StanzaNode header = (!)_header;
if (header.get_attribute_int("sid") <= 0) return;
foreach (StanzaNode key_node in header.get_subnodes("key")) {
if (key_node.get_attribute_int("rid") == store.local_registration_id) {
try {
string? payload = encrypted.get_deep_string_content("payload");
string? iv_node = header.get_deep_string_content("iv");
string? key_node_content = key_node.get_string_content();
if (payload == null || iv_node == null || key_node_content == null) continue;
uint8[] key;
uint8[] ciphertext = Base64.decode((!)payload);
uint8[] iv = Base64.decode((!)iv_node);
Address address = new Address(get_bare_jid((!)message.from), header.get_attribute_int("sid"));
if (key_node.get_attribute_bool("prekey")) {
PreKeySignalMessage msg = Plugin.get_context().deserialize_pre_key_signal_message(Base64.decode((!)key_node_content));
SessionCipher cipher = store.create_session_cipher(address);
key = cipher.decrypt_pre_key_signal_message(msg);
} else {
SignalMessage msg = Plugin.get_context().deserialize_signal_message(Base64.decode((!)key_node_content));
SessionCipher cipher = store.create_session_cipher(address);
key = cipher.decrypt_signal_message(msg);
}
address.device_id = 0; // TODO: Hack to have address obj live longer
if (key.length >= 32) {
int authtaglength = key.length - 16;
uint8[] new_ciphertext = new uint8[ciphertext.length + authtaglength];
uint8[] new_key = new uint8[16];
Memory.copy(new_ciphertext, ciphertext, ciphertext.length);
Memory.copy((uint8*)new_ciphertext + ciphertext.length, (uint8*)key + 16, authtaglength);
Memory.copy(new_key, key, 16);
ciphertext = new_ciphertext;
key = new_key;
}
message.body = arr_to_str(aes_decrypt(Cipher.AES_GCM_NOPADDING, key, iv, ciphertext));
flag.decrypted = true;
} catch (Error e) {
if (Plugin.DEBUG) print(@"OMEMO: Signal error while decrypting message: $(e.message)\n");
}
}
}
}
private string arr_to_str(uint8[] arr) {
// null-terminate the array
uint8[] rarr = new uint8[arr.length+1];
Memory.copy(rarr, arr, arr.length);
return (string)rarr;
}
public void request_user_devicelist(XmppStream stream, string jid) {
if (active_devicelist_requests.add(jid)) {
if (Plugin.DEBUG) print(@"OMEMO: requesting device list for $jid\n");
stream.get_module(Pubsub.Module.IDENTITY).request(stream, jid, NODE_DEVICELIST, (stream, jid, id, node) => on_devicelist(stream, jid, id ?? "", node));
}
}
public void on_devicelist(XmppStream stream, string jid, string id, StanzaNode? node_) {
StanzaNode node = node_ ?? new StanzaNode.build("list", NS_URI).add_self_xmlns();
string? my_jid = stream.get_flag(Bind.Flag.IDENTITY).my_jid;
if (my_jid == null) return;
if (jid == get_bare_jid((!)my_jid) && store.local_registration_id != 0) {
bool am_on_devicelist = false;
foreach (StanzaNode device_node in node.get_subnodes("device")) {
int device_id = device_node.get_attribute_int("id");
if (store.local_registration_id == device_id) {
am_on_devicelist = true;
}
}
if (!am_on_devicelist) {
if (Plugin.DEBUG) print(@"OMEMO: Not on device list, adding id\n");
node.put_node(new StanzaNode.build("device", NS_URI).put_attribute("id", store.local_registration_id.to_string()));
stream.get_module(Pubsub.Module.IDENTITY).publish(stream, jid, NODE_DEVICELIST, NODE_DEVICELIST, id, node);
} else {
publish_bundles_if_needed(stream, jid);
}
}
lock(device_lists) {
device_lists[jid] = new ArrayList<int32>();
foreach (StanzaNode device_node in node.get_subnodes("device")) {
device_lists[jid].add(device_node.get_attribute_int("id"));
}
}
active_devicelist_requests.remove(jid);
device_list_loaded(jid);
}
public void start_sessions_with(XmppStream stream, string bare_jid) {
if (!device_lists.has_key(bare_jid)) {
// TODO: manually request a device list
return;
}
Address address = new Address(bare_jid, 0);
foreach(int32 device_id in device_lists[bare_jid]) {
if (!is_ignored_device(bare_jid, device_id)) {
address.device_id = device_id;
try {
if (!store.contains_session(address)) {
start_session_with(stream, bare_jid, device_id);
}
} catch (Error e) {
// Ignore
}
}
}
address.device_id = 0;
}
public void start_session_with(XmppStream stream, string bare_jid, int device_id) {
if (active_bundle_requests.add(bare_jid + @":$device_id")) {
if (Plugin.DEBUG) print(@"OMEMO: Asking for bundle from $bare_jid:$device_id\n");
stream.get_module(Pubsub.Module.IDENTITY).request(stream, bare_jid, @"$NODE_BUNDLES:$device_id", (stream, jid, id, node) => {
on_other_bundle_result(stream, jid, device_id, id, node);
});
}
}
public bool is_known_address(string name) {
return device_lists.has_key(name);
}
public void ignore_device(string jid, int32 device_id) {
if (device_id <= 0) return;
lock (ignored_devices) {
if (!ignored_devices.has_key(jid)) {
ignored_devices[jid] = new ArrayList<int32>();
}
ignored_devices[jid].add(device_id);
}
session_start_failed(jid, device_id);
}
public bool is_ignored_device(string jid, int32 device_id) {
if (device_id <= 0) return true;
lock (ignored_devices) {
return ignored_devices.has_key(jid) && ignored_devices[jid].contains(device_id);
}
}
private void on_other_bundle_result(XmppStream stream, string jid, int device_id, string? id, StanzaNode? node) {
bool fail = false;
if (node == null) {
// Device not registered, shouldn't exist
fail = true;
} else {
Bundle bundle = new Bundle(node);
int32 signed_pre_key_id = bundle.signed_pre_key_id;
ECPublicKey? signed_pre_key = bundle.signed_pre_key;
uint8[] signed_pre_key_signature = bundle.signed_pre_key_signature;
ECPublicKey? identity_key = bundle.identity_key;
ArrayList<Bundle.PreKey> pre_keys = bundle.pre_keys;
int pre_key_idx = Random.int_range(0, pre_keys.size);
int32 pre_key_id = pre_keys[pre_key_idx].key_id;
ECPublicKey? pre_key = pre_keys[pre_key_idx].key;
if (signed_pre_key_id < 0 || signed_pre_key == null || identity_key == null || pre_key_id < 0 || pre_key == null) {
fail = true;
} else {
Address address = new Address(jid, device_id);
try {
if (store.contains_session(address)) {
return;
}
SessionBuilder builder = store.create_session_builder(address);
builder.process_pre_key_bundle(create_pre_key_bundle(device_id, device_id, pre_key_id, pre_key, signed_pre_key_id, signed_pre_key, signed_pre_key_signature, identity_key));
stream.get_module(IDENTITY).session_started(jid, device_id);
} catch (Error e) {
fail = true;
}
address.device_id = 0; // TODO: Hack to have address obj live longer
}
}
if (fail) {
stream.get_module(IDENTITY).ignore_device(jid, device_id);
}
stream.get_module(IDENTITY).active_bundle_requests.remove(jid + @":$device_id");
}
public void publish_bundles_if_needed(XmppStream stream, string jid) {
if (active_bundle_requests.add(jid + @":$(store.local_registration_id)")) {
stream.get_module(Pubsub.Module.IDENTITY).request(stream, jid, @"$NODE_BUNDLES:$(store.local_registration_id)", on_self_bundle_result);
}
}
private void on_self_bundle_result(XmppStream stream, string jid, string? id, StanzaNode? node) {
if (!Plugin.ensure_context()) return;
Map<int, ECPublicKey> keys = new HashMap<int, ECPublicKey>();
ECPublicKey? identity_key = null;
int32 signed_pre_key_id = -1;
ECPublicKey? signed_pre_key = null;
SignedPreKeyRecord? signed_pre_key_record = null;
bool changed = false;
if (node == null) {
identity_key = store.identity_key_pair.public;
changed = true;
} else {
Bundle bundle = new Bundle(node);
foreach (Bundle.PreKey prekey in bundle.pre_keys) {
ECPublicKey? key = prekey.key;
if (key != null) {
keys[prekey.key_id] = (!)key;
}
}
identity_key = bundle.identity_key;
signed_pre_key_id = bundle.signed_pre_key_id;;
signed_pre_key = bundle.signed_pre_key;
}
try {
// Validate IdentityKey
if (identity_key == null || store.identity_key_pair.public.compare((!)identity_key) != 0) {
changed = true;
}
IdentityKeyPair identity_key_pair = store.identity_key_pair;
// Validate signedPreKeyRecord + ID
if (signed_pre_key == null || signed_pre_key_id == -1 || !store.contains_signed_pre_key(signed_pre_key_id) || store.load_signed_pre_key(signed_pre_key_id).key_pair.public.compare((!)signed_pre_key) != 0) {
signed_pre_key_id = Random.int_range(1, int32.MAX); // TODO: No random, use ordered number
signed_pre_key_record = Plugin.get_context().generate_signed_pre_key(identity_key_pair, signed_pre_key_id);
store.store_signed_pre_key((!)signed_pre_key_record);
changed = true;
} else {
signed_pre_key_record = store.load_signed_pre_key(signed_pre_key_id);
}
// Validate PreKeys
Set<PreKeyRecord> pre_key_records = new HashSet<PreKeyRecord>();
foreach (var entry in keys.entries) {
if (store.contains_pre_key(entry.key)) {
PreKeyRecord record = store.load_pre_key(entry.key);
if (record.key_pair.public.compare(entry.value) == 0) {
pre_key_records.add(record);
}
}
}
int new_keys = NUM_KEYS_TO_PUBLISH - pre_key_records.size;
if (new_keys > 0) {
int32 next_id = Random.int_range(1, int32.MAX); // TODO: No random, use ordered number
Set<PreKeyRecord> new_records = Plugin.get_context().generate_pre_keys((uint)next_id, (uint)new_keys);
pre_key_records.add_all(new_records);
foreach (PreKeyRecord record in new_records) {
store.store_pre_key(record);
}
changed = true;
}
if (changed) {
publish_bundles(stream, (!)signed_pre_key_record, identity_key_pair, pre_key_records, (int32) store.local_registration_id);
}
} catch (Error e) {
if (Plugin.DEBUG) print(@"Unexpected error while publishing bundle: $(e.message)\n");
}
stream.get_module(IDENTITY).active_bundle_requests.remove(jid + @":$(store.local_registration_id)");
}
public static void publish_bundles(XmppStream stream, SignedPreKeyRecord signed_pre_key_record, IdentityKeyPair identity_key_pair, Set<PreKeyRecord> pre_key_records, int32 device_id) throws Error {
ECKeyPair tmp;
StanzaNode bundle = new StanzaNode.build("bundle", NS_URI)
.add_self_xmlns()
.put_node(new StanzaNode.build("signedPreKeyPublic", NS_URI)
.put_attribute("signedPreKeyId", signed_pre_key_record.id.to_string())
.put_node(new StanzaNode.text(Base64.encode((tmp = signed_pre_key_record.key_pair).public.serialize()))))
.put_node(new StanzaNode.build("signedPreKeySignature", NS_URI)
.put_node(new StanzaNode.text(Base64.encode(signed_pre_key_record.signature))))
.put_node(new StanzaNode.build("identityKey", NS_URI)
.put_node(new StanzaNode.text(Base64.encode(identity_key_pair.public.serialize()))));
StanzaNode prekeys = new StanzaNode.build("prekeys", NS_URI);
foreach (PreKeyRecord pre_key_record in pre_key_records) {
prekeys.put_node(new StanzaNode.build("preKeyPublic", NS_URI)
.put_attribute("preKeyId", pre_key_record.id.to_string())
.put_node(new StanzaNode.text(Base64.encode(pre_key_record.key_pair.public.serialize()))));
}
bundle.put_node(prekeys);
stream.get_module(Pubsub.Module.IDENTITY).publish(stream, null, @"$NODE_BUNDLES:$device_id", @"$NODE_BUNDLES:$device_id", "1", bundle);
}
public override void detach(XmppStream stream) {
}
public override string get_ns() {
return NS_URI;
}
public override string get_id() {
return IDENTITY.id;
}
}
}