diff options
Diffstat (limited to 'protocols/WhatsAppWeb/src/utils.cpp')
| -rw-r--r-- | protocols/WhatsAppWeb/src/utils.cpp | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/protocols/WhatsAppWeb/src/utils.cpp b/protocols/WhatsAppWeb/src/utils.cpp index 98bb9b2b3f..d956471e48 100644 --- a/protocols/WhatsAppWeb/src/utils.cpp +++ b/protocols/WhatsAppWeb/src/utils.cpp @@ -49,6 +49,102 @@ bool WhatsAppProto::getBlob(const char *szSetting, MBinBuffer &buf) } ///////////////////////////////////////////////////////////////////////////////////////// +// sends a piece of JSON to a server via a websocket, masked + +int WhatsAppProto::WSSend(const MessageLite &msg, WA_PKT_HANDLER /*pHandler*/, void * /*pUserInfo*/) +{ + if (m_hServerConn == nullptr) + return -1; + + // debugLogA("Sending packet: %s", msg..DebugString().c_str()); + + int cbLen = msg.ByteSize(); + ptrA protoBuf((char *)mir_alloc(cbLen)); + msg.SerializeToArray(protoBuf, cbLen); + + MBinBuffer payload; + m_noise->encodeFrame(protoBuf, cbLen, payload); + WebSocket_SendBinary(m_hServerConn, payload.data(), payload.length()); + return 0; +} + +///////////////////////////////////////////////////////////////////////////////////////// + +static char zeroData[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; + +int WhatsAppProto::WSSendNode(const char *pszPrefix, int flags, WANode &node, WA_PKT_HANDLER pHandler) +{ + if (m_hServerConn == nullptr) + return 0; + + { + char str[100]; + _i64toa(_time64(0), str, 10); + node.addAttr("epoch", str); + + CMStringA szText; + node.print(szText); + debugLogA("Sending binary node: %s", szText.c_str()); + } + + WAWriter writer; + writer.writeNode(&node); + + // AES block size = 16 bytes, let's expand data to block size boundary + size_t rest = writer.body.length() % 16; + if (rest != 0) + writer.body.append(zeroData, 16 - rest); + + BYTE iv[16]; + Utils_GetRandom(iv, sizeof(iv)); + + // allocate the buffer of the same size + 32 bytes for temporary operations + MBinBuffer enc; + enc.assign(writer.body.data(), writer.body.length()); + enc.append(mac_key.data(), mac_key.length()); + + int enc_len = 0, final_len = 0; + EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new(); + EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, (BYTE *)enc_key.data(), iv); + EVP_EncryptUpdate(ctx, (BYTE *)enc.data(), &enc_len, (BYTE *)writer.body.data(), (int)writer.body.length()); + EVP_EncryptFinal_ex(ctx, (BYTE *)enc.data() + enc_len, &final_len); + EVP_CIPHER_CTX_free(ctx); + + // build the resulting buffer of the following structure: + // - packet prefix + // - 32 bytes of HMAC + // - 16 bytes of iv + // - rest of encoded data + + BYTE hmac[32]; + unsigned int hmac_len = 32; + HMAC(EVP_sha256(), mac_key.data(), (int)mac_key.length(), (BYTE *)enc.data(), enc_len, hmac, &hmac_len); + + int pktId = ++m_iPktNumber; + + if (pHandler != nullptr) { + auto *pReq = new WARequest; + pReq->pHandler = pHandler; + pReq->szPrefix = pszPrefix; + + mir_cslock lck(m_csPacketQueue); + m_arPacketQueue.insert(pReq); + } + + char postPrefix[3] = {',', 0, (char)flags}; + + MBinBuffer ret; + ret.append(pszPrefix, strlen(pszPrefix)); + ret.append(postPrefix, sizeof(postPrefix)); + ret.append(hmac, sizeof(hmac)); + ret.append(iv, sizeof(iv)); + ret.append(enc.data(), enc_len); + WebSocket_SendBinary(m_hServerConn, ret.data(), ret.length()); + + return pktId; +} + +///////////////////////////////////////////////////////////////////////////////////////// bool WhatsAppProto::decryptBinaryMessage(size_t cbSize, const void *buf, MBinBuffer &res) { @@ -85,6 +181,109 @@ bool WhatsAppProto::decryptBinaryMessage(size_t cbSize, const void *buf, MBinBuf } ///////////////////////////////////////////////////////////////////////////////////////// +// WANoise members + +static uint8_t intro_header[] = { 87, 65, 6, DICT_VERSION }; +static uint8_t noise_init[] = "Noise_XX_25519_AESGCM_SHA256\0\0\0\0"; + +WANoise::WANoise() +{ + salt.assign(noise_init, 32); + encKey.assign(noise_init, 32); + decKey.assign(noise_init, 32); + + // generate ephemeral keys: public & private + ec_key_pair *pKeys; + curve_generate_key_pair(g_plugin.pCtx, &pKeys); + + auto *pPubKey = ec_key_pair_get_public(pKeys); + pubKey.assign(pPubKey->data, sizeof(pPubKey->data)); + + auto *pPrivKey = ec_key_pair_get_private(pKeys); + privKey.assign(pPrivKey->data, sizeof(pPrivKey->data)); + ec_key_pair_destroy(pKeys); + + // prepare hash + memcpy(hash, noise_init, 32); + updateHash(intro_header, 4); + updateHash(pubKey.data(), pubKey.length()); +} + +void WANoise::deriveKey(const void *pData, size_t cbLen, MBinBuffer &write, MBinBuffer &read) +{ + auto *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); + EVP_PKEY_derive_init(pctx); + EVP_PKEY_CTX_set_hkdf_md(pctx, EVP_sha256()); + EVP_PKEY_CTX_set1_hkdf_salt(pctx, salt.data(), (int)salt.length()); + EVP_PKEY_CTX_set1_hkdf_key(pctx, pData, (int)cbLen); + + size_t outlen = 64; + uint8_t out[64]; + EVP_PKEY_derive(pctx, out, &outlen); + + EVP_PKEY_CTX_free(pctx); + + write.assign(out, 32); + read.assign(out + 32, 32); +} + +void WANoise::mixIntoKey(const void *pData, size_t cbLen) +{ + deriveKey(pData, cbLen, salt, encKey); + decKey.assign(encKey.data(), encKey.length()); + readCounter = writeCounter = 0; +} + +bool WANoise::decodeFrame(const void *pData, size_t cbLen) +{ + if (!bInitFinished) { + proto::HandshakeMessage msg; + if (msg.ParseFromArray(pData, (int)cbLen)) { + auto &ephemeral = msg.serverhello().ephemeral(); + auto &static_ = msg.serverhello().static_(); + auto &payload = msg.serverhello().payload(); + + updateHash(ephemeral.c_str(), ephemeral.size()); + mixIntoKey(ephemeral.c_str(), ephemeral.size()); + + + } + return true; + } + + return false; +} + +void WANoise::encodeFrame(const void *pData, size_t cbLen, MBinBuffer &res) +{ + if (!bSendIntro) { + bSendIntro = true; + res.append(intro_header, 4); + } + + uint8_t buf[3]; + size_t foo = cbLen; + for (int i = 0; i < 3; i++) { + buf[2 - i] = foo & 0xFF; + foo >>= 8; + } + res.append(buf, 3); + res.append(pData, cbLen); +} + +void WANoise::updateHash(const void *pData, size_t cbLen) +{ + if (bInitFinished) + return; + + SHA256_CTX ctx; + SHA256_Init(&ctx); + SHA256_Update(&ctx, hash, sizeof(hash)); + SHA256_Update(&ctx, pData, cbLen); + SHA256_Final(hash, &ctx); +} + +///////////////////////////////////////////////////////////////////////////////////////// // WANode members WANode::WANode() |