From af4c366fdd259da073b2896ec92b102366c5da57 Mon Sep 17 00:00:00 2001
From: levlam <levlam@telegram.org>
Date: Sat, 11 Aug 2018 13:29:06 +0300
Subject: [PATCH] Remove legacy DH functions.

GitOrigin-RevId: 13efa3ef84b99095170df7f5c994482eb9606fe2
---
 td/mtproto/Handshake.cpp | 16 +++++++++-------
 td/mtproto/crypto.cpp    | 17 -----------------
 td/mtproto/crypto.h      |  5 -----
 3 files changed, 9 insertions(+), 29 deletions(-)

diff --git a/td/mtproto/Handshake.cpp b/td/mtproto/Handshake.cpp
index e7a5aeb03..f9062045c 100644
--- a/td/mtproto/Handshake.cpp
+++ b/td/mtproto/Handshake.cpp
@@ -171,8 +171,6 @@ Status AuthKeyHandshake::on_server_dh_params(Slice message, Callback *connection
     return Status::Error("SHA1 mismatch");
   }
 
-  // server_DH_inner_data#b5890dba nonce:int128 server_nonce:int128 g:int dh_prime:string g_a:string server_time:int =
-  // Server_DH_inner_data;
   if (dh_inner_data.nonce_ != nonce) {
     return Status::Error("Nonce mismatch");
   }
@@ -182,10 +180,12 @@ Status AuthKeyHandshake::on_server_dh_params(Slice message, Callback *connection
 
   server_time_diff = dh_inner_data.server_time_ - Time::now();
 
-  string g_b;
-  string auth_key_str;
-  TRY_STATUS(
-      dh_handshake(dh_inner_data.g_, dh_inner_data.dh_prime_, dh_inner_data.g_a_, &g_b, &auth_key_str, dh_callback));
+  DhHandshake handshake;
+  handshake.set_config(dh_inner_data.g_, dh_inner_data.dh_prime_);
+  handshake.set_g_a(dh_inner_data.g_a_);
+  TRY_STATUS(handshake.run_checks(false, dh_callback));
+  string g_b = handshake.get_g_b();
+  auto auth_key_params = handshake.gen_key();
 
   mtproto_api::client_DH_inner_data data(nonce, server_nonce, 0, g_b);
   size_t data_size = 4 + tl_calc_length(data);
@@ -205,7 +205,7 @@ Status AuthKeyHandshake::on_server_dh_params(Slice message, Callback *connection
   mtproto_api::set_client_DH_params set_client_dh_params(nonce, server_nonce, encrypted_data);
   send(connection, create_storer(set_client_dh_params));
 
-  auth_key = AuthKey(dh_auth_key_id(auth_key_str), std::move(auth_key_str));
+  auth_key = AuthKey(auth_key_params.first, std::move(auth_key_params.second));
   if (mode_ == Mode::Temp) {
     auth_key.set_expire_at(expire_at_);
   }
@@ -231,6 +231,7 @@ Status AuthKeyHandshake::on_dh_gen_response(Slice message, Callback *connection)
   }
   return Status::OK();
 }
+
 void AuthKeyHandshake::send(Callback *connection, const Storer &storer) {
   auto size = storer.size();
   auto writer = BufferWriter{size, 0, 0};
@@ -239,6 +240,7 @@ void AuthKeyHandshake::send(Callback *connection, const Storer &storer) {
   last_query_ = writer.as_buffer_slice();
   return do_send(connection, create_storer(last_query_.as_slice()));
 }
+
 void AuthKeyHandshake::do_send(Callback *connection, const Storer &storer) {
   return connection->send_no_crypto(storer);
 }
diff --git a/td/mtproto/crypto.cpp b/td/mtproto/crypto.cpp
index 59e287993..0b0846d12 100644
--- a/td/mtproto/crypto.cpp
+++ b/td/mtproto/crypto.cpp
@@ -241,12 +241,6 @@ Status DhHandshake::dh_check(const BigNum &prime, const BigNum &g_a, const BigNu
   return Status::OK();
 }
 
-int64 dh_auth_key_id(const string &auth_key) {
-  UInt<160> auth_key_sha1;
-  sha1(auth_key, auth_key_sha1.raw);
-  return as<int64>(auth_key_sha1.raw + 12);
-}
-
 void DhHandshake::set_config(int32 g_int, Slice prime_str) {
   has_config_ = true;
   prime_ = BigNum::from_binary(prime_str);
@@ -350,17 +344,6 @@ int64 DhHandshake::calc_key_id(const string &auth_key) {
   return as<int64>(auth_key_sha1.raw + 12);
 }
 
-Status dh_handshake(int g_int, Slice prime_str, Slice g_a_str, string *g_b_str, string *g_ab_str,
-                    DhCallback *callback) {
-  DhHandshake handshake;
-  handshake.set_config(g_int, prime_str);
-  handshake.set_g_a(g_a_str);
-  TRY_STATUS(handshake.run_checks(false, callback));
-  *g_b_str = handshake.get_g_b();
-  *g_ab_str = handshake.gen_key().second;
-  return Status::OK();
-}
-
 /*** KDF ***/
 void KDF(const string &auth_key, const UInt128 &msg_key, int X, UInt256 *aes_key, UInt256 *aes_iv) {
   CHECK(auth_key.size() == 2048 / 8);
diff --git a/td/mtproto/crypto.h b/td/mtproto/crypto.h
index 39e4cca70..2358dd6c9 100644
--- a/td/mtproto/crypto.h
+++ b/td/mtproto/crypto.h
@@ -158,11 +158,6 @@ class DhHandshake {
   BigNumContext ctx_;
 };
 
-// TODO: remove this legacy functions
-Status dh_handshake(int g_int, Slice prime_str, Slice g_a_str, string *g_b_str, string *g_ab_str,
-                    DhCallback *callback) TD_WARN_UNUSED_RESULT;
-int64 dh_auth_key_id(const string &auth_key);
-
 /*** KDF ***/
 void KDF(const string &auth_key, const UInt128 &msg_key, int X, UInt256 *aes_key, UInt256 *aes_iv);
 void tmp_KDF(const UInt128 &server_nonce, const UInt256 &new_nonce, UInt256 *tmp_aes_key, UInt256 *tmp_aes_iv);