Verify block id as part of block header validation for savanna blocks

[heifner]

For legacy blocks, the block id can't be verified until the action_mroot (merkle root of action receipts) is calculated which requires applying the transactions. For Savanna blocks the action_mroot is the finality_mroot (merkle root of the finality tree) which is known before applying the transactions.

For savanna blocks, verify the block id as part of block header validation.

[linh2931]

What about transaction_mroot? It is a part of block ID. It is unknown until transactions are applied.

[heifner]

What about transaction_mroot? It is a part of block ID. It is unknown until transactions are applied.

It is known before they are applied, see: https://github.com/AntelopeIO/spring/blob/main/libraries/chain/controller.cpp#L4127

[linh2931]

Thanks. I was looking at the transaction_mroot for producing.

[linh2931]

finality_mroot is known after valid structure built. To build valid structure, we need action_mroot (not the one in the header but the merkle root of action receipts)

spring/libraries/chain/block_state.cpp

Line 286 in af51472

valid_t block_state::new_valid(const block_header_state& next_bhs, const digest_type& action_mroot, const digest_type& strong_digest) const {

It is only available after transactions are applied. That's why 2 stages are currently used (step 7 in the Changes Required section): AntelopeIO/leap#2080.

Currently finality_tree root is checked by

spring/libraries/chain/controller.cpp

Line 3791 in af51472

EOS_ASSERT(bsp->finality_mroot() == actual_finality_mroot,

block id is checked by

spring/libraries/chain/controller.cpp

Line 3812 in af51472

EOS_ASSERT(producer_block_id == ab.id(), block_validate_exception, "Block ID does not match, ${producer_block_id} != ${validator_block_id}",

Not sure if we can move the checks any earlier.

I also think the following check is unnecessary as it uses the same value to check itself

spring/libraries/chain/controller.cpp

Line 4152 in af51472

EOS_ASSERT( id == bsp->id(), block_validate_exception,

[linh2931]

But we can verify action_mroot (Finality Tree Root) as early as in verify_basic_proper_block_invariants(). I will do that.