using Crypto;
using Dino;
using Dino.Entities;
using Gee;
using Signal;
using Xmpp;
using Xmpp.Xep;
namespace Dino.Plugins.JetOmemo {
private const string NS_URI = "urn:xmpp:jingle:jet-omemo:0";
private const string AES_128_GCM_URI = "urn:xmpp:ciphers:aes-128-gcm-nopadding";
public class Module : XmppStreamModule, Jet.EnvelopEncoding {
public static Xmpp.ModuleIdentity<Module> IDENTITY = new Xmpp.ModuleIdentity<Module>(NS_URI, "0396_jet_omemo");
private Omemo.Plugin plugin;
public Module(Omemo.Plugin plugin) {
this.plugin = plugin;
}
public override void attach(XmppStream stream) {
if (stream.get_module(Jet.Module.IDENTITY) != null) {
stream.get_module(ServiceDiscovery.Module.IDENTITY).add_feature(stream, NS_URI);
stream.get_module(Jet.Module.IDENTITY).register_envelop_encoding(this);
stream.get_module(Jet.Module.IDENTITY).register_cipher(new AesGcmCipher(16, AES_128_GCM_URI));
}
}
public override void detach(XmppStream stream) {
}
public bool is_available(XmppStream stream, Jid full_jid) {
bool? has_feature = stream.get_flag(ServiceDiscovery.Flag.IDENTITY).has_entity_feature(full_jid, NS_URI);
if (has_feature == null || !(!)has_feature) {
return false;
}
return stream.get_module(Xep.Jet.Module.IDENTITY).is_available(stream, full_jid);
}
public string get_type_uri() {
return Omemo.NS_URI;
}
public Jet.TransportSecret decode_envolop(XmppStream stream, Jid local_full_jid, Jid peer_full_jid, StanzaNode security) throws Jingle.IqError {
Store store = stream.get_module(Omemo.StreamModule.IDENTITY).store;
StanzaNode? encrypted = security.get_subnode("encrypted", Omemo.NS_URI);
if (encrypted == null) throw new Jingle.IqError.BAD_REQUEST("Invalid JET-OMEMO envelop: missing encrypted element");
StanzaNode? header = encrypted.get_subnode("header", Omemo.NS_URI);
if (header == null) throw new Jingle.IqError.BAD_REQUEST("Invalid JET-OMEMO envelop: missing header element");
string? iv_node = header.get_deep_string_content("iv");
if (header == null) throw new Jingle.IqError.BAD_REQUEST("Invalid JET-OMEMO envelop: missing iv element");
uint8[] iv = Base64.decode((!)iv_node);
foreach (StanzaNode key_node in header.get_subnodes("key")) {
if (key_node.get_attribute_int("rid") == store.local_registration_id) {
string? key_node_content = key_node.get_string_content();
uint8[] key;
Address address = new Address(peer_full_jid.bare_jid.to_string(), header.get_attribute_int("sid"));
if (key_node.get_attribute_bool("prekey")) {
PreKeySignalMessage msg = Omemo.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 = Omemo.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
uint8[] authtag = null;
if (key.length >= 32) {
int authtaglength = key.length - 16;
authtag = new uint8[authtaglength];
uint8[] new_key = new uint8[16];
Memory.copy(authtag, (uint8*)key + 16, 16);
Memory.copy(new_key, key, 16);
key = new_key;
}
// TODO: authtag?
return new Jet.TransportSecret(key, iv);
}
}
throw new Jingle.IqError.NOT_ACCEPTABLE("Not encrypted for targeted device");
}
public void encode_envelop(XmppStream stream, Jid local_full_jid, Jid peer_full_jid, Jet.SecurityParameters security_params, StanzaNode security) {
ArrayList<Account> accounts = plugin.app.stream_interactor.get_accounts();
Store store = stream.get_module(Omemo.StreamModule.IDENTITY).store;
Account? account = null;
foreach (Account compare in accounts) {
if (compare.bare_jid.equals_bare(local_full_jid)) {
account = compare;
break;
}
}
if (account == null) {
// TODO
critical("Sending from offline account %s", local_full_jid.to_string());
}
StanzaNode header_node;
StanzaNode encrypted_node = new StanzaNode.build("encrypted", Omemo.NS_URI).add_self_xmlns()
.put_node(header_node = new StanzaNode.build("header", Omemo.NS_URI)
.put_attribute("sid", store.local_registration_id.to_string())
.put_node(new StanzaNode.build("iv", Omemo.NS_URI)
.put_node(new StanzaNode.text(Base64.encode(security_params.secret.initialization_vector)))));
plugin.trust_manager.encrypt_key(header_node, security_params.secret.transport_key, local_full_jid.bare_jid, new ArrayList<Jid>.wrap(new Jid[] {peer_full_jid.bare_jid}), stream, account);
security.put_node(encrypted_node);
}
public override string get_ns() { return NS_URI; }
public override string get_id() { return IDENTITY.id; }
}
public class AesGcmCipher : Jet.Cipher, Object {
private int key_size;
private string uri;
public AesGcmCipher(int key_size, string uri) {
this.key_size = key_size;
this.uri = uri;
}
public string get_cipher_uri() {
return uri;
}
public Jet.TransportSecret generate_random_secret() {
uint8[] iv = new uint8[16];
Omemo.Plugin.get_context().randomize(iv);
uint8[] key = new uint8[key_size];
Omemo.Plugin.get_context().randomize(key);
return new Jet.TransportSecret(key, iv);
}
public InputStream wrap_input_stream(InputStream input, Jet.TransportSecret secret) requires (secret.transport_key.length == key_size) {
SymmetricCipher cipher = new SymmetricCipher("AES-GCM");
cipher.set_key(secret.transport_key);
cipher.set_iv(secret.initialization_vector);
return new ConverterInputStream(input, new SymmetricCipherDecrypter((owned) cipher, 16));
}
public OutputStream wrap_output_stream(OutputStream output, Jet.TransportSecret secret) requires (secret.transport_key.length == key_size) {
Crypto.SymmetricCipher cipher = new SymmetricCipher("AES-GCM");
cipher.set_key(secret.transport_key);
cipher.set_iv(secret.initialization_vector);
return new ConverterOutputStream(output, new SymmetricCipherEncrypter((owned) cipher, 16));
}
}
}
