WhatsApp: fix for reading & decrypting messages

7 files changed, 64 insertions, 13 deletions

diff --git a/protocols/WhatsApp/src/crypt.cpp b/protocols/WhatsApp/src/crypt.cpp
index 09a14f53b0..1efb93dde4 100644
--- a/protocols/WhatsApp/src/crypt.cpp
+++ b/protocols/WhatsApp/src/crypt.cpp
@@ -21,8 +21,10 @@ MBinBuffer aesDecrypt(
 	if (additionalLen)
 		EVP_DecryptUpdate(ctx, nullptr, &tag_len, (uint8_t *)additionalData, (int)additionalLen);
 
-	dataLen -= 16;
-	EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, 16, (uint8_t *)data + dataLen);
+	if (cipher == EVP_aes_256_gcm()) {
+		dataLen -= 16;
+		EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, 16, (uint8_t *)data + dataLen);
+	}
 
 	MBinBuffer ret;
 	uint8_t outbuf[2000];
diff --git a/protocols/WhatsApp/src/message.cpp b/protocols/WhatsApp/src/message.cpp
index 2479ba0458..1397c7c17c 100644
--- a/protocols/WhatsApp/src/message.cpp
+++ b/protocols/WhatsApp/src/message.cpp
@@ -129,7 +129,14 @@ void WhatsAppProto::OnReceiveMessage(const WANode &node)
 
 			iDecryptable++;
 
+			auto c = msgBody.data() + msgBody.len() - 1;
+			if (*c <= 0x10)
+				msgBody.reset(msgBody.len() - *c);
+
 			proto::Message encMsg(msgBody.data(), msgBody.len());
+			if (!encMsg)
+				throw "Invalid decoded message";
+
 			if (encMsg->devicesentmessage)
 				msg.message = encMsg->devicesentmessage->message;
 			else
@@ -155,7 +162,8 @@ void WhatsAppProto::OnReceiveMessage(const WANode &node)
 
 			SendReceipt(szChatId, pszReceiptTo, msgId, pszReceiptType);
 		}
-		catch (const char *) {
+		catch (const char *pszError) {
+			debugLogA("Message decryption failed with error: %s", pszError);
 		}
 
 		if (!iDecryptable) {
diff --git a/protocols/WhatsApp/src/proto.h b/protocols/WhatsApp/src/proto.h
index 965fbb7ce6..5f315d3ace 100644
--- a/protocols/WhatsApp/src/proto.h
+++ b/protocols/WhatsApp/src/proto.h
@@ -169,6 +169,7 @@ public:
 
 	__forceinline session_cipher* getCipher(void) const { return cipher; }
 	__forceinline int getDeviceId() const { return address.device_id; }
+	CMStringA getSetting() const;
 };
 
 class MSignalStore
diff --git a/protocols/WhatsApp/src/protobuf-c/protobuf-c.h b/protocols/WhatsApp/src/protobuf-c/protobuf-c.h
index 5fa52da626..c66fa000e3 100644
--- a/protocols/WhatsApp/src/protobuf-c/protobuf-c.h
+++ b/protocols/WhatsApp/src/protobuf-c/protobuf-c.h
@@ -209,6 +209,8 @@ size_t foo__bar__baz_bah__pack_to_buffer
 # define PROTOBUF_C__END_DECLS
 #endif
 
+#define PROTOBUF_C_UNPACK_ERROR OutputDebugStringA
+
 PROTOBUF_C__BEGIN_DECLS
 
 #if defined(_WIN32) && defined(PROTOBUF_C_USE_SHARED_LIB)
diff --git a/protocols/WhatsApp/src/signal.cpp b/protocols/WhatsApp/src/signal.cpp
index 8207a7462d..1a59fb443b 100644
--- a/protocols/WhatsApp/src/signal.cpp
+++ b/protocols/WhatsApp/src/signal.cpp
@@ -35,7 +35,7 @@ MSignalStore::~MSignalStore()
 void MSignalStore::logError(int err, const char *pszMessage)
 {
 	if (err < 0) {
-		pProto->debugLogA("libsignal error %d: %s", err, pszMessage);
+		pProto->debugLogA("libsignal error %d", err);
 		throw pszMessage;
 	}
 }
@@ -100,7 +100,8 @@ static int contains_session_func(const signal_protocol_address *address, void *u
 	auto *pStore = (MSignalStore *)user_data;
 
 	MSignalSession tmp(CMStringA(address->name, (int)address->name_len), address->device_id);
-	return pStore->arSessions.find(&tmp) == nullptr;
+	ptrA data(pStore->pProto->getStringA(tmp.getSetting()));
+	return data == nullptr;
 }
 
 static int delete_all_sessions_func(const char *name, size_t name_len, void *user_data)
@@ -111,6 +112,7 @@ static int delete_all_sessions_func(const char *name, size_t name_len, void *use
 	int count = 0;
 	for (auto &it : pList.rev_iter()) {
 		if (it->hasAddress(name, name_len)) {
+			pStore->pProto->delSetting(it->getSetting());
 			pList.remove(pList.indexOf(&it));
 			count++;
 		}
@@ -125,8 +127,10 @@ int delete_session_func(const signal_protocol_address *address, void *user_data)
 
 	MSignalSession tmp(CMStringA(address->name, (int)address->name_len), address->device_id);
 	int idx = pList.getIndex(&tmp);
-	if (idx != -1)
+	if (idx != -1) {
+		pStore->pProto->delSetting(tmp.getSetting());
 		pList.remove(idx);
+	}
 	return 0;
 }
 
@@ -156,13 +160,21 @@ int load_session_func(signal_buffer **record, signal_buffer **user_data_storage,
 	auto *pStore = (MSignalStore *)user_data;
 
 	MSignalSession tmp(CMStringA(address->name, (int)address->name_len), address->device_id);
-	if (auto *pSession = pStore->arSessions.find(&tmp)) {
-		*record = signal_buffer_create((uint8_t *)pSession->sessionData.data(), pSession->sessionData.length());
-		*user_data_storage = signal_buffer_create((uint8_t *)pSession->userData.data(), pSession->userData.length());
-		return 1;
-	}
+	auto *pSession = pStore->arSessions.find(&tmp);
+	if (pSession == nullptr) {
+		ptrA szSession(pStore->pProto->getStringA(tmp.getSetting()));
+		if (szSession == nullptr)
+			return 0;
 
-	return 0;
+		JSONNode root = JSONNode::parse(szSession);
+		pSession = new MSignalSession(tmp);
+		pSession->sessionData = decodeBufStr(root["data"].as_string());
+		pSession->userData = decodeBufStr(root["user"].as_string());
+	}
+		
+	*record = signal_buffer_create((uint8_t *)pSession->sessionData.data(), pSession->sessionData.length());
+	*user_data_storage = signal_buffer_create((uint8_t *)pSession->userData.data(), pSession->userData.length());
+	return 1;
 }
 
 static int store_session_func(const signal_protocol_address *address, uint8_t *record, size_t record_len, uint8_t *user_record, size_t user_record_len, void *user_data)
@@ -178,6 +190,10 @@ static int store_session_func(const signal_protocol_address *address, uint8_t *r
 
 	pSession->sessionData.assign(record, record_len);
 	pSession->userData.assign(user_record, user_record_len);
+
+	JSONNode root;
+	root << CHAR_PARAM("data", ptrA(mir_base64_encode(record, record_len))) << CHAR_PARAM("user", ptrA(mir_base64_encode(user_record, user_record_len)));
+	pStore->pProto->setString(pSession->getSetting(), root.write().c_str());	
 	return 0;
 }
 
@@ -256,6 +272,9 @@ static int load_signed_pre_key(signal_buffer **record, uint32_t signed_pre_key_i
 {
 	auto *pStore = (MSignalStore *)user_data;
 
+	if (signed_pre_key_id == 0)
+		signed_pre_key_id = 1;
+
 	CMStringA szSetting(FORMAT, "%s%d", "SignedPreKey", signed_pre_key_id);
 	MBinBuffer blob(pStore->pProto->getBlob(szSetting));
 	if (blob.data() == 0) {
@@ -442,6 +461,11 @@ bool MSignalSession::hasAddress(const char *name, size_t name_len) const
 	return memcmp(address.name, name, name_len) == 0;
 }
 
+CMStringA MSignalSession::getSetting() const
+{
+	return CMStringA(FORMAT, "%s_%s_%d", "SignalSession", szName.c_str(), getDeviceId());
+}
+
 /////////////////////////////////////////////////////////////////////////////////////////
 
 MSignalSession* MSignalStore::createSession(const CMStringA &szName, int deviceId)
@@ -575,6 +599,6 @@ void MSignalStore::generatePrekeys(int count)
 
 /////////////////////////////////////////////////////////////////////////////////////////
 
-void MSignalStore::processSenderKeyMessage(const Wa__Message__SenderKeyDistributionMessage *)
+void MSignalStore::processSenderKeyMessage(const Wa__Message__SenderKeyDistributionMessage *msg)
 {
 }
diff --git a/protocols/WhatsApp/src/utils.cpp b/protocols/WhatsApp/src/utils.cpp
index 592d509253..983a98a3f7 100644
--- a/protocols/WhatsApp/src/utils.cpp
+++ b/protocols/WhatsApp/src/utils.cpp
@@ -224,6 +224,19 @@ std::string decodeBinStr(const std::string &buf)
 	return res;
 }
 
+MBinBuffer decodeBufStr(const std::string &buf)
+{
+	MBinBuffer res;
+	size_t cbLen;
+	void *pData = mir_base64_decode(buf.c_str(), &cbLen);
+	if (pData == nullptr)
+		return res;
+
+	res.assign(pData, cbLen);
+	mir_free(pData);
+	return res;
+}
+
 uint32_t decodeBigEndian(const ProtobufCBinaryData &buf)
 {
 	uint32_t ret = 0;
diff --git a/protocols/WhatsApp/src/utils.h b/protocols/WhatsApp/src/utils.h
index a3163ad88d..f102c47c2a 100644
--- a/protocols/WhatsApp/src/utils.h
+++ b/protocols/WhatsApp/src/utils.h
@@ -203,6 +203,7 @@ CMStringA file2string(const wchar_t *pwszFileName);
 CMStringA directPath2url(const char *pszDirectPath);
 
 std::string decodeBinStr(const std::string &buf);
+MBinBuffer decodeBufStr(const std::string &buf);
 
 MBinBuffer aesDecrypt(
 	const EVP_CIPHER *cipher,