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//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2025
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#pragma once
#include "td/e2e/Blockchain.h"
#include "td/e2e/Container.h"
#include "td/e2e/e2e_api.h"
#include "td/utils/SharedSlice.h"
#include "td/utils/Slice.h"
#include "td/utils/SliceBuilder.h"
#include "td/utils/Status.h"
#include "td/utils/StringBuilder.h"
#include "td/utils/Time.h"
#include "td/utils/UInt.h"
#include "td/utils/VectorQueue.h"
#include <map>
#include <set>
#include <utility>
namespace tde2e_core {
using tde2e_api::CallVerificationState;
using tde2e_api::CallVerificationWords;
struct CallVerificationChain {
enum State {
End,
Commit,
Reveal,
};
State get_state() const;
void on_new_main_block(const Blockchain &blockhain);
td::Status try_apply_block(td::Slice message);
std::string to_short_string(e2e::object_ptr<e2e::e2e_chain_GroupBroadcast> &broadcast);
CallVerificationState get_verification_state() const;
CallVerificationWords get_verification_words() const;
void set_user_id(td::int64 user_id) {
user_id_ = user_id;
}
void allow_delay() {
delay_allowed_ = true;
}
void skip_signatures_validation() {
may_skip_signatures_validation_ = true;
}
friend td::StringBuilder &operator<<(td::StringBuilder &sb, const CallVerificationChain &chain);
private:
td::Status process_broadcast(std::string message, e2e::object_ptr<e2e::e2e_chain_GroupBroadcast> broadcast);
td::Status process_broadcast(e2e::e2e_chain_groupBroadcastNonceCommit &nonce_commit);
td::Status process_broadcast(e2e::e2e_chain_groupBroadcastNonceReveal &nonce_reveal);
State state_{End};
CallVerificationState verification_state_;
CallVerificationWords verification_words_;
td::int32 height_{-1};
td::UInt256 last_block_hash_{};
std::map<td::int64, PublicKey> participant_keys_;
std::map<td::int64, std::string> committed_;
std::map<td::int64, std::string> revealed_;
td::int64 user_id_{};
td::Timestamp commit_at_{};
td::Timestamp reveal_at_{};
td::Timestamp done_at_{};
struct UserState {
td::Timestamp receive_commit_at_{};
td::Timestamp receive_reveal_at_{};
};
std::map<td::int64, UserState> users_;
bool delay_allowed_{false};
bool may_skip_signatures_validation_{false};
std::map<td::int32, std::vector<std::pair<std::string, e2e::object_ptr<e2e::e2e_chain_GroupBroadcast>>>>
delayed_broadcasts_;
};
class CallEncryption {
public:
CallEncryption(td::int64 user_id, PrivateKey private_key);
td::Status add_shared_key(td::int32 epoch, td::UInt256 epoch_hash, td::SecureString key, GroupStateRef group_state);
void forget_shared_key(td::int32 epoch, td::UInt256 epoch_hash);
td::Result<std::string> decrypt(td::int64 expected_user_id, td::int32 expected_channel_id, td::Slice encrypted_data);
td::Result<std::string> encrypt(td::int32 channel_id, td::Slice decrypted_data);
private:
static constexpr double FORGET_EPOCH_DELAY = 10;
static constexpr td::int32 MAX_ACTIVE_EPOCHS = 15;
td::int64 user_id_{};
PrivateKey private_key_;
struct EpochInfo {
EpochInfo(td::int32 epoch, td::UInt256 epoch_hash, td::int64 user_id, td::SecureString secret,
GroupStateRef group_state)
: epoch_(epoch)
, epoch_hash_(epoch_hash)
, user_id_(user_id)
, secret_(std::move(secret))
, group_state_(std::move(group_state)) {
}
td::int32 epoch_{};
td::UInt256 epoch_hash_{};
td::int64 user_id_{};
td::SecureString secret_;
GroupStateRef group_state_;
};
std::map<td::int32, td::uint32> seqno_;
std::map<td::int32, EpochInfo> epochs_;
std::map<td::UInt256, td::int32> epoch_by_hash_;
td::VectorQueue<std::pair<td::Timestamp, td::int32>> epochs_to_forget_;
std::map<std::pair<PublicKey, td::int32>, std::set<td::uint32>> seen_;
void sync();
td::Result<std::string> encrypt_packet_with_secret(td::int32 channel_id, td::Slice header, td::Slice packet,
td::Slice one_time_secret);
td::Result<std::string> decrypt_packet_with_secret(td::int64 expected_user_id, td::int32 expected_channel_id,
td::Slice unencrypted_packet, td::Slice encrypted_packet,
td::Slice one_time_secret, const GroupStateRef &group_state);
td::Status check_not_seen(const PublicKey &public_key, td::int32 channel_id, td::uint32 seqno);
void mark_as_seen(const PublicKey &public_key, td::int32 channel_id, td::uint32 seqno);
static td::Status validate_channel_id(td::int32 channel_id);
};
class CallVerification {
public:
static CallVerification create(td::int64 user_id, PrivateKey private_key, const Blockchain &blockchain);
void on_new_main_block(const Blockchain &blockhain);
CallVerificationState get_verification_state() const;
std::vector<std::string> pull_outbound_messages();
CallVerificationWords get_verification_words() const;
td::Status receive_inbound_message(td::Slice message);
friend td::StringBuilder &operator<<(td::StringBuilder &sb, const CallVerification &verification);
private:
td::int64 user_id_{};
PrivateKey private_key_;
CallVerificationChain chain_;
std::vector<tde2e_api::Bytes> pending_outbound_messages_;
bool sent_commit_{false};
bool sent_reveal_{false};
td::int32 height_{-1};
td::UInt256 last_block_hash_{};
td::UInt256 nonce_{};
};
struct Call {
static td::Result<std::string> create_zero_block(const PrivateKey &private_key, GroupStateRef group_state);
static td::Result<std::string> create_self_add_block(const PrivateKey &private_key, td::Slice previous_block,
const GroupParticipant &self);
static td::Result<Call> create(td::int64 user_id, PrivateKey private_key, td::Slice last_block);
static td::Result<std::vector<Change>> make_changes_for_new_state(GroupStateRef group_state);
td::Result<std::string> build_change_state(GroupStateRef new_group_state) const;
td::Result<td::int32> get_height() const;
td::Result<GroupStateRef> get_group_state() const;
td::Status apply_block(td::Slice block);
td::Status get_status() const {
if (status_.is_error()) {
return Error(E::CallFailed, PSLICE() << status_);
}
return td::Status::OK();
}
td::Result<td::SecureString> shared_key() const {
TRY_STATUS(get_status());
return group_shared_key_.copy();
}
td::Result<std::string> decrypt(td::int64 user_id, td::int32 channel_id, td::Slice encrypted_data) {
TRY_STATUS(get_status());
return call_encryption_.decrypt(user_id, channel_id, encrypted_data);
}
td::Result<std::string> encrypt(td::int32 channel_id, td::Slice decrypted_data) {
TRY_STATUS(get_status());
return call_encryption_.encrypt(channel_id, decrypted_data);
}
td::Result<std::vector<std::string>> pull_outbound_messages() {
TRY_STATUS(get_status());
return call_verification_.pull_outbound_messages();
}
td::Result<CallVerificationState> get_verification_state() const {
TRY_STATUS(get_status());
return call_verification_.get_verification_state();
}
td::Result<CallVerificationWords> get_verification_words() const {
TRY_STATUS(get_status());
return call_verification_.get_verification_words();
}
td::Result<CallVerificationState> receive_inbound_message(td::Slice verification_message) {
TRY_STATUS(get_status());
// For now, don't fail the call in case of some errors
TRY_RESULT(local_verification_message, Blockchain::from_server_to_local(verification_message.str()));
TRY_STATUS(call_verification_.receive_inbound_message(local_verification_message));
return get_verification_state();
}
friend td::StringBuilder &operator<<(td::StringBuilder &sb, const Call &call);
private:
td::Status status_{td::Status::OK()};
td::int64 user_id_{0};
PrivateKey private_key_;
ClientBlockchain blockchain_;
CallVerification call_verification_;
CallEncryption call_encryption_;
td::SecureString group_shared_key_;
Call(td::int64 user_id, PrivateKey pk, ClientBlockchain blockchain);
td::Status update_group_shared_key();
td::Status do_apply_block(td::Slice block);
td::Result<td::SecureString> decrypt_shared_key();
};
} // namespace tde2e_core
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