Properly decrypt messages from MUCs

This commit is contained in:
Samuel Hand 2018-08-14 01:37:55 +01:00
parent 65724233f0
commit 3c819a19e1
2 changed files with 75 additions and 97 deletions

View file

@ -20,7 +20,6 @@ public class StreamModule : XmppStreamModule {
private ConcurrentSet<string> active_bundle_requests = new ConcurrentSet<string>();
private ConcurrentSet<Jid> active_devicelist_requests = new ConcurrentSet<Jid>();
private Map<Jid, ArrayList<int32>> ignored_devices = new HashMap<Jid, ArrayList<int32>>(Jid.hash_bare_func, Jid.equals_bare_func);
private ReceivedPipelineListener received_pipeline_listener;
public signal void store_created(Store store);
public signal void device_list_loaded(Jid jid, ArrayList<int32> devices);
@ -31,13 +30,10 @@ public class StreamModule : XmppStreamModule {
this.store = Plugin.get_context().create_store();
store_created(store);
received_pipeline_listener = new ReceivedPipelineListener(store);
stream.get_module(MessageModule.IDENTITY).received_pipeline.connect(received_pipeline_listener);
stream.get_module(Pubsub.Module.IDENTITY).add_filtered_notification(stream, NODE_DEVICELIST, (stream, jid, id, node) => on_devicelist(stream, jid, id, node));
}
public override void detach(XmppStream stream) {
stream.get_module(MessageModule.IDENTITY).received_pipeline.disconnect(received_pipeline_listener);
}
public void request_user_devicelist(XmppStream stream, Jid jid) {
@ -273,80 +269,4 @@ public class StreamModule : XmppStreamModule {
}
}
public class ReceivedPipelineListener : StanzaListener<MessageStanza> {
private const string[] after_actions_const = {"EXTRACT_MESSAGE_2"};
public override string action_group { get { return "ENCRYPT_BODY"; } }
public override string[] after_actions { get { return after_actions_const; } }
private Store store;
public ReceivedPipelineListener(Store store) {
this.store = store;
}
public override async bool run(XmppStream stream, MessageStanza message) {
StanzaNode? _encrypted = message.stanza.get_subnode("encrypted", NS_URI);
if (_encrypted == null || MessageFlag.get_flag(message) != null || message.from == null) return false;
StanzaNode encrypted = (!)_encrypted;
if (!Plugin.ensure_context()) return false;
MessageFlag flag = new MessageFlag();
message.add_flag(flag);
StanzaNode? _header = encrypted.get_subnode("header");
if (_header == null) return false;
StanzaNode header = (!)_header;
if (header.get_attribute_int("sid") <= 0) return false;
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(message.from.bare_jid.to_string(), 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");
}
}
}
return false;
}
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;
}
}
}

View file

@ -168,27 +168,85 @@ public class TrustManager {
}
public override async bool run(Entities.Message message, Xmpp.MessageStanza stanza, Conversation conversation) {
MessageFlag? flag = MessageFlag.get_flag(stanza);
if(flag != null && ((!)flag).decrypted) {
int identity_id = db.identity.get_id(conversation.account.id);
if (identity_id < 0) return false;
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(identity_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;
Store store = stream_interactor.module_manager.get_module(conversation.account, StreamModule.IDENTITY).store;
StanzaNode? _encrypted = stanza.stanza.get_subnode("encrypted", NS_URI);
if (_encrypted == null || MessageFlag.get_flag(stanza) != null || stanza.from == null) return false;
StanzaNode encrypted = (!)_encrypted;
if (!Plugin.ensure_context()) return false;
MessageFlag flag = new MessageFlag();
stanza.add_flag(flag);
StanzaNode? _header = encrypted.get_subnode("header");
if (_header == null) return false;
StanzaNode header = (!)_header;
if (header.get_attribute_int("sid") <= 0) return false;
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);
Jid jid = stanza.from;
if (conversation.type_ == Conversation.Type.GROUPCHAT) {
jid = stream_interactor.get_module(MucManager.IDENTITY).get_real_jid(jid, conversation.account);
}
Address address = new Address(jid.bare_jid.to_string(), 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;
int identity_id = db.identity.get_id(conversation.account.id);
if (identity_id < 0) return false;
Database.IdentityMetaTable.TrustLevel trust_level = (Database.IdentityMetaTable.TrustLevel) db.identity_meta.get_device(identity_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;
}
} catch (Error e) {
if (Plugin.DEBUG) print(@"OMEMO: Signal error while decrypting message: $(e.message)\n");
}
}
}
return false;
}
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;
}
}
}