first version that successfully logs into

5 files changed, 203 insertions, 54 deletions

diff --git a/protocols/WhatsAppWeb/src/db.h b/protocols/WhatsAppWeb/src/db.h
index 90f084acb1..49ea39f062 100644
--- a/protocols/WhatsAppWeb/src/db.h
+++ b/protocols/WhatsAppWeb/src/db.h
@@ -17,8 +17,11 @@ Copyright © 2019 George Hazan
 #define DBKEY_SERVER_TOKEN            "ServerToken"
 #define DBKEY_BROWSER_TOKEN           "BrowserToken"
 
-#define DBKEY_PUBKEY                  "PublicKey"
-#define DBKEY_PRIVATEKEY              "PrivateKey"
+#define DBKEY_PUB_KEY                 "PublicKey"
+#define DBKEY_PRIVATE_KEY             "PrivateKey"
+
+#define DBKEY_MAC_KEY                 "MacKey"
+#define DBKEY_ENC_KEY                 "EncKey"
 
 #define DBKEY_NICK                    "Nick"
 #define DBKEY_DEF_GROUP               "DefaultGroup"
diff --git a/protocols/WhatsAppWeb/src/main.cpp b/protocols/WhatsAppWeb/src/main.cpp
index 0f63d3ba80..790cabcc07 100644
--- a/protocols/WhatsAppWeb/src/main.cpp
+++ b/protocols/WhatsAppWeb/src/main.cpp
@@ -28,7 +28,43 @@ PLUGININFOEX pluginInfo = {
 
 extern "C" __declspec(dllexport) const MUUID MirandaInterfaces[] = { MIID_PROTOCOL, MIID_LAST };
 
-/////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+
+static int hmac_sha256_init(void **hmac_context, const uint8_t *key, size_t key_len, void *)
+{
+	HMAC_CTX *ctx = new HMAC_CTX;
+	*hmac_context = ctx;
+	HMAC_Init(ctx, key, key_len, EVP_sha256());
+	return 0;
+}
+
+int hmac_sha256_update(void *hmac_context, const uint8_t *data, size_t data_len, void *)
+{
+	return HMAC_Update((HMAC_CTX *)hmac_context, data, data_len);
+}
+
+int hmac_sha256_final(void *hmac_context, signal_buffer **output, void *user_data)
+{
+	BYTE data[200];
+	unsigned len = 0;
+	if (!HMAC_Final((HMAC_CTX *)hmac_context, data, &len))
+		return 1;
+
+	*output = signal_buffer_create(data, len);
+	return 0;
+}
+
+void hmac_sha256_cleanup(void *hmac_context, void *)
+{
+	HMAC_cleanup((HMAC_CTX *)hmac_context);
+	delete hmac_context;
+}
+
+static int random_func(uint8_t *pData, size_t size, void *)
+{
+	Utils_GetRandom(pData, size);
+	return 0;
+}
 
 CMPlugin::CMPlugin() :
 	ACCPROTOPLUGIN<WhatsAppProto>(MODULENAME, pluginInfo)
@@ -44,6 +80,18 @@ int CMPlugin::Load()
 	// InitIcons();
 	// InitContactMenus();
 
+	//////////////////////////////////////////////////////////////////////////////////////
+	signal_context_create(&pCtx, nullptr);
+
+	signal_crypto_provider prov;
+	memset(&prov, 0xFF, sizeof(prov));
+	prov.hmac_sha256_init_func = hmac_sha256_init;
+	prov.hmac_sha256_final_func = hmac_sha256_final;
+	prov.hmac_sha256_update_func = hmac_sha256_update;
+	prov.hmac_sha256_cleanup_func = hmac_sha256_cleanup;
+	prov.random_func = random_func;
+	signal_context_set_crypto_provider(pCtx, &prov);
+
 	return 0;
 }
 
@@ -52,5 +100,6 @@ int CMPlugin::Load()
 
 int CMPlugin::Unload()
 {
+	signal_context_destroy(pCtx);
 	return 0;
 }
diff --git a/protocols/WhatsAppWeb/src/proto.h b/protocols/WhatsAppWeb/src/proto.h
index 7f8cff994a..493adec54e 100644
--- a/protocols/WhatsAppWeb/src/proto.h
+++ b/protocols/WhatsAppWeb/src/proto.h
@@ -41,6 +41,7 @@ class WhatsAppProto : public PROTO<WhatsAppProto>
 	CMStringW m_tszAvatarFolder;
 
 	MBinBuffer mac_key, enc_key;
+	bool getBlob(const char *pSetting, MBinBuffer &buf);
 
 	EVP_PKEY *m_pKeys; // private & public keys
 
@@ -64,7 +65,8 @@ class WhatsAppProto : public PROTO<WhatsAppProto>
 	void StartSession(void);
 	void ShutdownSession(void);
 
-	void ProcessChallenge(const CMStringA &szChallenge);
+	bool ProcessChallenge(const CMStringA &szChallenge);
+	bool ProcessSecret(const CMStringA &szSecret);
 
 	/// Request handlers ///////////////////////////////////////////////////////////////////
 
@@ -132,6 +134,8 @@ public:
 
 struct CMPlugin : public ACCPROTOPLUGIN<WhatsAppProto>
 {
+	signal_context *pCtx;
+
 	CMPlugin();
 
 	int Load() override;
diff --git a/protocols/WhatsAppWeb/src/server.cpp b/protocols/WhatsAppWeb/src/server.cpp
index be9fc55200..8b183ab308 100644
--- a/protocols/WhatsAppWeb/src/server.cpp
+++ b/protocols/WhatsAppWeb/src/server.cpp
@@ -101,53 +101,46 @@ static INT_PTR __stdcall sttShowDialog(void *param)
 
 /////////////////////////////////////////////////////////////////////////////////////////
 
-static int random_func(uint8_t *pData, size_t size, void *)
-{
-	Utils_GetRandom(pData, size);
-	return 0;
-}
-
 bool WhatsAppProto::ShowQrCode(const CMStringA &ref)
 {
-	CMStringA szPubKey(getMStringA(DBKEY_PUBKEY));
-	if (szPubKey.IsEmpty()) {
+	MBinBuffer pubKey;
+	if (!getBlob(DBKEY_PUB_KEY, pubKey)) {
 		// generate new pair of private & public keys for this account
-		signal_context *pTmpCtx;
-		signal_context_create(&pTmpCtx, nullptr);
-
-		signal_crypto_provider prov;
-		memset(&prov, 0xFF, sizeof(prov));
-		prov.random_func = random_func;
-		signal_context_set_crypto_provider(pTmpCtx, &prov);
 
 		ec_key_pair *pKeys;
-		if (curve_generate_key_pair(pTmpCtx, &pKeys)) {
-			signal_context_destroy(pTmpCtx);
+		if (curve_generate_key_pair(g_plugin.pCtx, &pKeys))
 			return false;
-		}
 
 		auto *pPubKey = ec_key_pair_get_public(pKeys);
-		signal_buffer *pBuf;
-		ec_public_key_serialize(&pBuf, pPubKey);
-		szPubKey = ptrA(mir_base64_encode(&pBuf->data, pBuf->len));
-		signal_buffer_free(pBuf);
-		setString(DBKEY_PUBKEY, szPubKey);
+		pubKey.append(pPubKey->data, sizeof(pPubKey->data));
+		db_set_blob(0, m_szModuleName, DBKEY_PUB_KEY, pPubKey->data, sizeof(pPubKey->data));
 
 		auto *pPrivKey = ec_key_pair_get_private(pKeys);
-		ec_private_key_serialize(&pBuf, pPrivKey);
-		CMStringA szPrivKey(ptrA(mir_base64_encode(&pBuf->data, pBuf->len)));
-		signal_buffer_free(pBuf);
-		setString(DBKEY_PRIVATEKEY, szPrivKey);
+		db_set_blob(0, m_szModuleName, DBKEY_PRIVATE_KEY, pPrivKey->data, sizeof(pPrivKey->data));
+		ec_key_pair_destroy(pKeys);
 	}
 
 	CallFunctionSync(sttShowDialog, this);
 
-	CMStringA szQrData(FORMAT, "%s,%s,%s", ref.c_str(), szPubKey.c_str(), m_szClientId.c_str());
+	CMStringA szQrData(FORMAT, "%s,%s,%s", ref.c_str(), ptrA(mir_base64_encode(pubKey.data(), pubKey.length())).get(), m_szClientId.c_str());
 	m_pQRDlg->SetData(szQrData);
 	return true;
 }
 
-//////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+
+bool WhatsAppProto::getBlob(const char *szSetting, MBinBuffer &buf)
+{
+	DBVARIANT dbv = { DBVT_BLOB };
+	if (db_get(0, m_szModuleName, szSetting, &dbv))
+		return false;
+
+	buf.append(dbv.pbVal, dbv.cpbVal);
+	db_free(&dbv);
+	return true;
+}
+
+/////////////////////////////////////////////////////////////////////////////////////////
 // sends a piece of JSON to a server via a websocket, masked
 
 int WhatsAppProto::WSSend(const CMStringA &str, WA_PKT_HANDLER pHandler)
@@ -183,7 +176,9 @@ void WhatsAppProto::OnLoggedIn()
 {
 	debugLogA("CDiscordProto::OnLoggedIn");
 	m_bOnline = true;
-	// SetServerStatus(m_iDesiredStatus);
+
+	ProtoBroadcastAck(0, ACKTYPE_STATUS, ACKRESULT_SUCCESS, (HANDLE)m_iStatus, m_iDesiredStatus);
+	m_iStatus = m_iDesiredStatus;
 }
 
 void WhatsAppProto::OnLoggedOut(void)
@@ -199,29 +194,105 @@ void WhatsAppProto::OnLoggedOut(void)
 	setAllContactStatuses(ID_STATUS_OFFLINE, false);
 }
 
-//////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
 
-void WhatsAppProto::ProcessChallenge(const CMStringA &szChallenge)
+bool WhatsAppProto::ProcessChallenge(const CMStringA &szChallenge)
 {
-	if (mac_key.isEmpty()) {
-		ShutdownSession();
-		return;
-	}
+	if (szChallenge.IsEmpty() || mac_key.isEmpty())
+		return false;
 
 	size_t cbLen;
 	void *pChallenge = mir_base64_decode(szChallenge, &cbLen);
 
 	BYTE digest[32];
 	unsigned cbResult = sizeof(digest);
-	HMAC(EVP_sha256(), mac_key.data(), mac_key.length(), (BYTE*)pChallenge, cbLen, digest, &cbResult);
+	HMAC(EVP_sha256(), mac_key.data(), (int)mac_key.length(), (BYTE*)pChallenge, (int)cbLen, digest, &cbResult);
 
 	ptrA szServer(getStringA(DBKEY_SERVER_TOKEN));
 	CMStringA payload(FORMAT, "[\"admin\",\"challenge\",\"%s\",\"%s\",\"%s\"]",
 		ptrA(mir_base64_encode(digest, cbResult)).get(), szServer.get(), m_szClientId.c_str());
 	WSSend(payload);
+	return true;
 }
 
-//////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
+
+bool WhatsAppProto::ProcessSecret(const CMStringA &szSecret)
+{
+	if (szSecret.IsEmpty())
+		return false;
+
+	size_t secretLen = 0;
+	mir_ptr<BYTE> pSecret((BYTE *)mir_base64_decode(szSecret, &secretLen));
+	if (pSecret == nullptr || secretLen != 144) {
+		debugLogA("Invalid secret key, dropping session (secret len = %u", (unsigned)secretLen);
+		return false;
+	}
+
+	ec_public_key pPeerPublic;
+	memcpy(pPeerPublic.data, pSecret, 32);
+
+	MBinBuffer privKey;
+	if (!getBlob(DBKEY_PRIVATE_KEY, privKey))
+		return false;
+
+	ec_private_key pMyPrivate;
+	memcpy(pMyPrivate.data, privKey.data(), 32);
+
+	uint8_t *pSharedKey, *pSharedExpanded;
+	int sharedLen = curve_calculate_agreement(&pSharedKey, &pPeerPublic, &pMyPrivate);
+	{
+		BYTE salt[32], md[32];
+		unsigned int md_len = 32;
+		memset(salt, 0, sizeof(salt));
+		HMAC(EVP_sha256(), salt, sizeof(salt), pSharedKey, sharedLen, md, &md_len);
+
+		hkdf_context *pHKDF;
+		hkdf_create(&pHKDF, 3, g_plugin.pCtx);
+		hkdf_expand(pHKDF, &pSharedExpanded, md, sizeof(md), 0, 0, 80);
+		hkdf_destroy(pHKDF);
+	}
+
+	// validation
+	{
+		unsigned int md_len = 32;
+		BYTE sum[32], md[32], enc[112], *key = pSharedExpanded + 32;
+		memcpy(enc, pSecret, 32);
+		memcpy(enc + 32, (BYTE *)pSecret + 64, 80);
+		memcpy(sum, (BYTE *)pSecret + 32, 32);
+		HMAC(EVP_sha256(), key, 32, enc, sizeof(enc), md, &md_len);
+		if (memcmp(md, sum, 32)) {
+			debugLogA("Secret key validation failed, exiting");
+			return false;
+		}
+	}
+
+	// woohoo, everything is ok, decrypt keys
+	{
+		BYTE enc[80], dec[112], key[32], iv[16];
+		memcpy(key, pSharedExpanded, sizeof(key));
+		memcpy(key, pSharedExpanded+64, sizeof(iv));
+		memcpy(enc, pSecret.get() + 64, sizeof(enc));
+
+		int dec_len = 0, final_len = 0;
+		EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
+		EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv);
+		EVP_DecryptUpdate(ctx, dec, &dec_len, enc, sizeof(enc));
+		EVP_DecryptFinal_ex(ctx, dec + dec_len, &final_len);
+		dec_len += final_len;
+		EVP_CIPHER_CTX_free(ctx);
+
+		enc_key.append(dec, 32);
+		mac_key.append(dec + 32, 32);
+
+		db_set_blob(0, m_szModuleName, DBKEY_ENC_KEY, enc_key.data(), (int)enc_key.length());
+		db_set_blob(0, m_szModuleName, DBKEY_MAC_KEY, mac_key.data(), (int)mac_key.length());
+	}
+
+	return true;
+}
+
+/////////////////////////////////////////////////////////////////////////////////////////
 
 void WhatsAppProto::RestoreSession()
 {
@@ -239,16 +310,13 @@ void WhatsAppProto::OnRestoreSession(const JSONNode &root)
 {
 	int status = root["status"].as_int();
 	if (status != 200) {
-		debugLogA("Attmept to restore session failed with error %d", status);
-		delSetting(DBKEY_CLIENT_TOKEN);
-		delSetting(DBKEY_SERVER_TOKEN);
-
+		debugLogA("Attempt to restore session failed with error %d", status);
 		ShutdownSession();
 		return;
 	}
 }
 
-//////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
 
 void WhatsAppProto::ShutdownSession()
 {
@@ -264,7 +332,7 @@ void WhatsAppProto::ShutdownSession()
 	OnLoggedOut();
 }
 
-//////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
 
 void WhatsAppProto::StartSession()
 {
@@ -285,7 +353,7 @@ void WhatsAppProto::OnStartSession(const JSONNode &root)
 	ShowQrCode(ref);
 }
 
-//////////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////////////////////////////////////////////////////////
 // gateway worker thread
 
 void WhatsAppProto::ServerThread(void *)
@@ -314,7 +382,10 @@ bool WhatsAppProto::ServerThreadWorker()
 
 	m_iLoginTime = time(0);
 	m_szClientToken = getMStringA(DBKEY_CLIENT_TOKEN);
-	if (m_szClientToken.IsEmpty())
+	getBlob(DBKEY_ENC_KEY, enc_key);
+	getBlob(DBKEY_MAC_KEY, mac_key);
+
+	if (m_szClientToken.IsEmpty() || mac_key.isEmpty() || enc_key.isEmpty())
 		StartSession();
 	else
 		RestoreSession();
@@ -458,8 +529,10 @@ void WhatsAppProto::ProcessCmd(const JSONNode &root)
 	CMStringW wszType(root["type"].as_mstring());
 	if (wszType == L"challenge") {
 		CMStringA szChallenge(root["challenge"].as_mstring());
-		if (!szChallenge.IsEmpty())
-			ProcessChallenge(szChallenge);
+		if (!ProcessChallenge(szChallenge)) {
+			ShutdownSession();
+			return;
+		}
 	}
 }
 
@@ -474,8 +547,10 @@ void WhatsAppProto::ProcessConn(const JSONNode &root)
 	setString(DBKEY_ID, m_szJid);
 
 	CMStringA szSecret(root["secret"].as_mstring());
-	size_t secretLen;
-	void *pSecret = mir_base64_decode(szSecret, &secretLen);
+	if (!ProcessSecret(szSecret)) {
+		ShutdownSession();
+		return;
+	}
 
 	setWString(DBKEY_NICK, root["pushname"].as_mstring());
 	setWString(DBKEY_CLIENT_TOKEN, root["clientToken"].as_mstring());
diff --git a/protocols/WhatsAppWeb/src/stdafx.h b/protocols/WhatsAppWeb/src/stdafx.h
index 82f1e715c0..34c6f485c8 100644
--- a/protocols/WhatsAppWeb/src/stdafx.h
+++ b/protocols/WhatsAppWeb/src/stdafx.h
@@ -46,7 +46,9 @@ Copyright © 2019 George Hazan
 #include <openssl/hmac.h>
 
 #include "../../libs/libqrencode/src/qrencode.h"
+
 #include "../../libs/libsignal/src/curve.h"
+#include "../../libs/libsignal/src/hkdf.h"
 #include "../../libs/libsignal/src/signal_protocol.h"
 
 struct signal_buffer
@@ -55,6 +57,22 @@ struct signal_buffer
 	uint8_t data[];
 };
 
+struct signal_type_base
+{
+	unsigned int ref_count = 0;
+	void (*destroy)(signal_type_base *instance) = 0;
+};
+
+struct ec_public_key : public signal_type_base
+{
+	uint8_t data[32];
+};
+
+struct ec_private_key : public signal_type_base
+{
+	uint8_t data[32];
+};
+
 #include "db.h"
 #include "proto.h"
 #include "resource.h"