diff --git a/Telegram/SourceFiles/boxes/connection_box.cpp b/Telegram/SourceFiles/boxes/connection_box.cpp
index b00003bb60..7a8730d01a 100644
--- a/Telegram/SourceFiles/boxes/connection_box.cpp
+++ b/Telegram/SourceFiles/boxes/connection_box.cpp
@@ -738,8 +738,7 @@ ProxyData ProxyBox::collectData() {
 	} else if ((result.type == Type::Http || result.type == Type::Socks5)
 		&& !result.password.isEmpty() && result.user.isEmpty()) {
 		_user->showError();
-	} else if (result.type == Type::Mtproto
-		&& result.password.size() != 32) {
+	} else if (result.type == Type::Mtproto && !result.valid()) {
 		_secret->showError();
 	} else if (!result) {
 		_host->showError();
@@ -850,7 +849,7 @@ void ProxyBox::setupMtprotoCredentials(const ProxyData &data) {
 		st::connectionUserInputField,
 		langFactory(lng_connection_proxy_secret_ph),
 		(data.type == Type::Mtproto) ? data.password : QString());
-	_secret->setMaxLength(32);
+	_secret->setMaxLength(ProxyData::MaxMtprotoPasswordLength());
 	_secret->move(0, 0);
 	_secret->heightValue(
 	) | rpl::start_with_next([=, wrap = secretWrap.data()](int height) {
@@ -1107,7 +1106,7 @@ void ProxiesBoxController::refreshChecker(Item &item) {
 		item.checker->connectToServer(
 			item.data.host,
 			item.data.port,
-			MTP::ProtocolSecretFromPassword(item.data.password),
+			item.data.secretFromMtprotoPassword(),
 			dcId);
 	} else {
 		const auto options = mtproto->dcOptions()->lookup(
diff --git a/Telegram/SourceFiles/core/utils.cpp b/Telegram/SourceFiles/core/utils.cpp
index e8bcf478b0..3c438d8b45 100644
--- a/Telegram/SourceFiles/core/utils.cpp
+++ b/Telegram/SourceFiles/core/utils.cpp
@@ -240,12 +240,16 @@ namespace {
 bool ProxyData::valid() const {
 	if (type == Type::None || host.isEmpty() || !port) {
 		return false;
-	} else if (type == Type::Mtproto && !ValidSecret(password)) {
+	} else if (type == Type::Mtproto && !ValidMtprotoPassword(password)) {
 		return false;
 	}
 	return true;
 }
 
+int ProxyData::MaxMtprotoPasswordLength() {
+	return 34;
+}
+
 bool ProxyData::supportsCalls() const {
 	return (type == Type::Socks5);
 }
@@ -258,6 +262,34 @@ bool ProxyData::tryCustomResolve() const {
 		).match(host).hasMatch();
 }
 
+bytes::vector ProxyData::secretFromMtprotoPassword() const {
+	Expects(type == Type::Mtproto);
+	Expects(password.size() % 2 == 0);
+
+	const auto length = password.size() / 2;
+	const auto fromHex = [](QChar ch) -> int {
+		const auto code = int(ch.unicode());
+		if (code >= '0' && code <= '9') {
+			return (code - '0');
+		} else if (code >= 'A' && code <= 'F') {
+			return 10 + (code - 'A');
+		} else if (ch >= 'a' && ch <= 'f') {
+			return 10 + (code - 'a');
+		}
+		return -1;
+	};
+	auto result = bytes::vector(length);
+	for (auto i = 0; i != length; ++i) {
+		const auto high = fromHex(password[2 * i]);
+		const auto low = fromHex(password[2 * i + 1]);
+		if (high < 0 || low < 0) {
+			return {};
+		}
+		result[i] = static_cast<gsl::byte>(high * 16 + low);
+	}
+	return result;
+}
+
 ProxyData::operator bool() const {
 	return valid();
 }
@@ -277,8 +309,15 @@ bool ProxyData::operator!=(const ProxyData &other) const {
 	return !(*this == other);
 }
 
-bool ProxyData::ValidSecret(const QString &secret) {
-	return QRegularExpression("^[a-fA-F0-9]{32}$").match(secret).hasMatch();
+bool ProxyData::ValidMtprotoPassword(const QString &secret) {
+	if (secret.size() == 32) {
+		static const auto check = QRegularExpression("^[a-fA-F0-9]{32}$");
+		return check.match(secret).hasMatch();
+	} else if (secret.size() == 34) {
+		static const auto check = QRegularExpression("^dd[a-fA-F0-9]{32}$");
+		return check.match(secret).hasMatch();
+	}
+	return false;
 }
 
 ProxyData ToDirectIpProxy(const ProxyData &proxy, int ipIndex) {
diff --git a/Telegram/SourceFiles/core/utils.h b/Telegram/SourceFiles/core/utils.h
index 1e71dd3e3e..bdc258ea9b 100644
--- a/Telegram/SourceFiles/core/utils.h
+++ b/Telegram/SourceFiles/core/utils.h
@@ -12,6 +12,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/flags.h"
 #include "base/algorithm.h"
 #include "base/assertion.h"
+#include "base/bytes.h"
 
 #include <QtCore/QReadWriteLock>
 #include <QtCore/QRegularExpression>
@@ -400,11 +401,13 @@ struct ProxyData {
 	bool valid() const;
 	bool supportsCalls() const;
 	bool tryCustomResolve() const;
+	bytes::vector secretFromMtprotoPassword() const;
 	explicit operator bool() const;
 	bool operator==(const ProxyData &other) const;
 	bool operator!=(const ProxyData &other) const;
 
-	static bool ValidSecret(const QString &secret);
+	static bool ValidMtprotoPassword(const QString &secret);
+	static int MaxMtprotoPasswordLength();
 
 };
 
diff --git a/Telegram/SourceFiles/mtproto/connection_abstract.cpp b/Telegram/SourceFiles/mtproto/connection_abstract.cpp
index 2e1bdd75d0..8d72dfec4c 100644
--- a/Telegram/SourceFiles/mtproto/connection_abstract.cpp
+++ b/Telegram/SourceFiles/mtproto/connection_abstract.cpp
@@ -14,38 +14,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 namespace MTP {
 namespace internal {
-namespace {
-
-bytes::vector ProtocolSecretFromPassword(const QString &password) {
-	const auto size = password.size();
-	if (size % 2) {
-		return {};
-	}
-	const auto length = size / 2;
-	const auto fromHex = [](QChar ch) -> int {
-		const auto code = int(ch.unicode());
-		if (code >= '0' && code <= '9') {
-			return (code - '0');
-		} else if (code >= 'A' && code <= 'F') {
-			return 10 + (code - 'A');
-		} else if (ch >= 'a' && ch <= 'f') {
-			return 10 + (code - 'a');
-		}
-		return -1;
-	};
-	auto result = bytes::vector(length);
-	for (auto i = 0; i != length; ++i) {
-		const auto high = fromHex(password[2 * i]);
-		const auto low = fromHex(password[2 * i + 1]);
-		if (high < 0 || low < 0) {
-			return {};
-		}
-		result[i] = static_cast<gsl::byte>(high * 16 + low);
-	}
-	return result;
-}
-
-} // namespace
 
 ConnectionPointer::ConnectionPointer() = default;
 
@@ -189,9 +157,4 @@ ConnectionPointer AbstractConnection::Create(
 }
 
 } // namespace internal
-
-bytes::vector ProtocolSecretFromPassword(const QString &password) {
-	return internal::ProtocolSecretFromPassword(password);
-}
-
 } // namespace MTP
diff --git a/Telegram/SourceFiles/mtproto/connection_abstract.h b/Telegram/SourceFiles/mtproto/connection_abstract.h
index 02c1b898b5..70fe80e30e 100644
--- a/Telegram/SourceFiles/mtproto/connection_abstract.h
+++ b/Telegram/SourceFiles/mtproto/connection_abstract.h
@@ -11,9 +11,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/bytes.h"
 
 namespace MTP {
-
-bytes::vector ProtocolSecretFromPassword(const QString &password);
-
 namespace internal {
 
 struct ConnectionOptions;
diff --git a/Telegram/SourceFiles/mtproto/connection_tcp.cpp b/Telegram/SourceFiles/mtproto/connection_tcp.cpp
index 978c08623e..156aa956fb 100644
--- a/Telegram/SourceFiles/mtproto/connection_tcp.cpp
+++ b/Telegram/SourceFiles/mtproto/connection_tcp.cpp
@@ -512,8 +512,7 @@ void TcpConnection::connectToServer(
 	if (_proxy.type == ProxyData::Type::Mtproto) {
 		_address = _proxy.host;
 		_port = _proxy.port;
-		_protocol = Protocol::Create(
-			ProtocolSecretFromPassword(_proxy.password));
+		_protocol = Protocol::Create(_proxy.secretFromMtprotoPassword());
 
 		DEBUG_LOG(("TCP Info: "
 			"dc:%1 - Connecting to proxy '%2'"