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Merge pull request #226 from peerplays-network/feature/GRPH-160

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[GRPH-160] check witness signature before adding block to fork db
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pbattu123 2020-02-13 09:00:22 -04:00 committed by GitHub
commit c93c3d3b18
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GPG key ID: 4AEE18F83AFDEB23
4 changed files with 148 additions and 65 deletions
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86
libraries/chain/db_block.cpp
View file

@ -39,6 +39,7 @@
#include <graphene/chain/protocol/fee_schedule.hpp>
#include <graphene/chain/exceptions.hpp>
#include <graphene/chain/evaluator.hpp>
#include <graphene/chain/witness_schedule_object.hpp>
#include <fc/crypto/digest.hpp>
#include <fc/smart_ref_impl.hpp>
@ -197,12 +198,18 @@ bool database::push_block(const signed_block& new_block, uint32_t skip)
bool database::_push_block(const signed_block& new_block)
{ try {
uint32_t skip = get_node_properties().skip_flags;
if( !(skip&skip_fork_db) )
{
/// TODO: if the block is greater than the head block and before the next maitenance interval
// verify that the block signer is in the current set of active witnesses.
const auto now = fc::time_point::now().sec_since_epoch();
if( _fork_db.head() && new_block.timestamp.sec_since_epoch() > now - 86400 )
{
// verify that the block signer is in the current set of active witnesses.
shared_ptr<fork_item> prev_block = _fork_db.fetch_block( new_block.previous );
GRAPHENE_ASSERT( prev_block, unlinkable_block_exception, "block does not link to known chain" );
if( prev_block->scheduled_witnesses && !(skip&(skip_witness_schedule_check|skip_witness_signature)) )
verify_signing_witness( new_block, *prev_block );
}
shared_ptr<fork_item> new_head = _fork_db.push_block(new_block);
//If the head block from the longest chain does not build off of the current head, we need to switch forks.
if( new_head->data.previous != head_block_id() )
{
@ -228,6 +235,7 @@ bool database::_push_block(const signed_block& new_block)
try {
undo_database::session session = _undo_db.start_undo_session();
apply_block( (*ritr)->data, skip );
update_witnesses( **ritr );
_block_id_to_block.store( (*ritr)->id, (*ritr)->data );
session.commit();
}
@ -268,11 +276,12 @@ bool database::_push_block(const signed_block& new_block)
}
else return false;
}
}
try {
auto session = _undo_db.start_undo_session();
apply_block(new_block, skip);
if( new_block.timestamp.sec_since_epoch() > now - 86400 )
update_witnesses( *new_head );
_block_id_to_block.store(new_block.id(), new_block);
session.commit();
} catch ( const fc::exception& e ) {
@ -284,6 +293,73 @@ bool database::_push_block(const signed_block& new_block)
return false;
} FC_CAPTURE_AND_RETHROW( (new_block) ) }
void database::verify_signing_witness( const signed_block& new_block, const fork_item& fork_entry )const
{
FC_ASSERT( new_block.timestamp >= fork_entry.next_block_time );
uint32_t slot_num = ( new_block.timestamp - fork_entry.next_block_time ).to_seconds() / block_interval();
const global_property_object& gpo = get_global_properties();
if (gpo.parameters.witness_schedule_algorithm == GRAPHENE_WITNESS_SHUFFLED_ALGORITHM)
{
uint64_t index = ( fork_entry.next_block_aslot + slot_num ) % fork_entry.scheduled_witnesses->size();
const auto& scheduled_witness = (*fork_entry.scheduled_witnesses)[index];
FC_ASSERT( new_block.witness == scheduled_witness.first, "Witness produced block at wrong time",
("block witness",new_block.witness)("scheduled",scheduled_witness)("slot_num",slot_num) );
FC_ASSERT( new_block.validate_signee( scheduled_witness.second ) );
}
if (gpo.parameters.witness_schedule_algorithm == GRAPHENE_WITNESS_SCHEDULED_ALGORITHM &&
slot_num != 0 )
{
witness_id_type wid;
const witness_schedule_object& wso = get_witness_schedule_object();
// ask the near scheduler who goes in the given slot
bool slot_is_near = wso.scheduler.get_slot(slot_num-1, wid);
if(! slot_is_near)
{
// if the near scheduler doesn't know, we have to extend it to
// a far scheduler.
// n.b. instantiating it is slow, but block gaps long enough to
// need it are likely pretty rare.
witness_scheduler_rng far_rng(wso.rng_seed.begin(), GRAPHENE_FAR_SCHEDULE_CTR_IV);
far_future_witness_scheduler far_scheduler =
far_future_witness_scheduler(wso.scheduler, far_rng);
if(!far_scheduler.get_slot(slot_num-1, wid))
{
// no scheduled witness -- somebody set up us the bomb
// n.b. this code path is impossible, the present
// implementation of far_future_witness_scheduler
// returns true unconditionally
assert( false );
}
}
FC_ASSERT( new_block.witness == wid, "Witness produced block at wrong time",
("block witness",new_block.witness)("scheduled",wid)("slot_num",slot_num) );
FC_ASSERT( new_block.validate_signee( wid(*this).signing_key ) );
}
}
void database::update_witnesses( fork_item& fork_entry )const
{
if( fork_entry.scheduled_witnesses ) return;
const dynamic_global_property_object& dpo = get_dynamic_global_properties();
fork_entry.next_block_aslot = dpo.current_aslot + 1;
fork_entry.next_block_time = get_slot_time( 1 );
const witness_schedule_object& wso = get_witness_schedule_object();
fork_entry.scheduled_witnesses = std::make_shared< vector< pair< witness_id_type, public_key_type > > >();
fork_entry.scheduled_witnesses->reserve( wso.current_shuffled_witnesses.size() );
for( size_t i = 0; i < wso.current_shuffled_witnesses.size(); ++i )
{
const auto& witness = wso.current_shuffled_witnesses[i](*this);
fork_entry.scheduled_witnesses->emplace_back( wso.current_shuffled_witnesses[i], witness.signing_key );
}
}
/**
* Attempts to push the transaction into the pending queue
*

2
libraries/chain/db_witness_schedule.cpp
View file

@ -45,7 +45,7 @@ witness_id_type database::get_scheduled_witness( uint32_t slot_num )const
if (gpo.parameters.witness_schedule_algorithm == GRAPHENE_WITNESS_SCHEDULED_ALGORITHM &&
slot_num != 0 )
{
const witness_schedule_object& wso = get_witness_schedule_object();;
const witness_schedule_object& wso = get_witness_schedule_object();
// ask the near scheduler who goes in the given slot
bool slot_is_near = wso.scheduler.get_slot(slot_num-1, wid);
if(! slot_is_near)

2
libraries/chain/include/graphene/chain/database.hpp
View file

@ -494,6 +494,8 @@ namespace graphene { namespace chain {
const witness_object& validate_block_header( uint32_t skip, const signed_block& next_block )const;
const witness_object& _validate_block_header( const signed_block& next_block )const;
void verify_signing_witness( const signed_block& new_block, const fork_item& fork_entry )const;
void update_witnesses( fork_item& fork_entry )const;
void create_block_summary(const signed_block& next_block);
//////////////////// db_witness_schedule.cpp ////////////////////

5
libraries/chain/include/graphene/chain/fork_database.hpp
View file

@ -51,6 +51,11 @@ namespace graphene { namespace chain {
bool invalid = false;
block_id_type id;
signed_block data;
// contains witness block signing keys scheduled *after* the block has been applied
shared_ptr< vector< pair< witness_id_type, public_key_type > > > scheduled_witnesses;
uint64_t next_block_aslot = 0;
fc::time_point_sec next_block_time;
};
typedef shared_ptr<fork_item> item_ptr;