from ethereum import tester as t from ethereum import utils, state_transition, transactions, abi from viper import compiler import serpent from ethereum.slogging import LogRecorder, configure_logging, set_level config_string = ':info,eth.vm.log:trace,eth.vm.op:trace,eth.vm.stack:trace,eth.vm.exit:trace,eth.pb.msg:trace,eth.pb.tx:debug' #configure_logging(config_string=config_string) import rlp s = t.state() t.languages['viper'] = compiler.Compiler() t.gas_limit = 9999999 EPOCH_LENGTH = 100 def inject_tx(txhex): tx = rlp.decode(utils.decode_hex(txhex[2:]), transactions.Transaction) s.state.set_balance(tx.sender, tx.startgas * tx.gasprice) state_transition.apply_transaction(s.state, tx) contract_address = utils.mk_contract_address(tx.sender, 0) assert s.state.get_code(contract_address) return contract_address code_template = """ ~calldatacopy(0, 0, 128) ~call(3000, 1, 0, 0, 128, 0, 32) return(~mload(0) == %s) """ def mk_validation_code(address): return serpent.compile(code_template % (utils.checksum_encode(address))) # Install RLP decoder library rlp_decoder_address = inject_tx( '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') # Install sig hasher s.state.set_balance('0x6e7406512b244843c1171840dfcd3d7532d979fe', 7291200000000000) sighasher_address = inject_tx( '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') # Install purity checker purity_checker_address = inject_tx( '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') ct = abi.ContractTranslator([{'name': 'check(address)', 'type': 'function', 'constant': True, 'inputs': [{'name': 'addr', 'type': 'address'}], 'outputs': [{'name': 'out', 'type': 'bool'}]}, {'name': 'submit(address)', 'type': 'function', 'constant': False, 'inputs': [{'name': 'addr', 'type': 'address'}], 'outputs': [{'name': 'out', 'type': 'bool'}]}]) # Check that the RLP decoding library and the sig hashing library are "pure" assert utils.big_endian_to_int(s.send(t.k0, purity_checker_address, 0, ct.encode('submit', [rlp_decoder_address]))) == 1 assert utils.big_endian_to_int(s.send(t.k0, purity_checker_address, 0, ct.encode('submit', [sighasher_address]))) == 1 k1_valcode_addr = s.send(t.k0, "", 0, mk_validation_code(t.a0)) assert utils.big_endian_to_int(s.send(t.k0, purity_checker_address, 0, ct.encode('submit', [k1_valcode_addr]))) == 1 # Install Casper casper_code = open('simple_casper.v.py').read().replace('0x1Db3439a222C519ab44bb1144fC28167b4Fa6EE6', utils.checksum_encode(k1_valcode_addr)) \ .replace('0x476c2cA9a7f3B16FeCa86512276271FAf63B6a24', utils.checksum_encode(sighasher_address)) \ .replace('0xD7a3BD6C9eA32efF147d067f907AE6b22d436F91', utils.checksum_encode(purity_checker_address)) print('Casper code length', len(compiler.compile(casper_code))) casper = s.abi_contract(casper_code, language='viper', startgas=5555555) print('Gas consumed to launch Casper', s.state.receipts[-1].gas_used - s.state.receipts[-2].gas_used) # Helper functions for making a prepare, commit, login and logout message def mk_prepare(validator_index, epoch, hash, ancestry_hash, source_epoch, source_ancestry_hash, key): sighash = utils.sha3(rlp.encode([validator_index, epoch, hash, ancestry_hash, source_epoch, source_ancestry_hash])) v, r, s = utils.ecdsa_raw_sign(sighash, key) sig = utils.encode_int32(v) + utils.encode_int32(r) + utils.encode_int32(s) return rlp.encode([validator_index, epoch, hash, ancestry_hash, source_epoch, source_ancestry_hash, sig]) def mk_commit(validator_index, epoch, hash, prev_commit_epoch, key): sighash = utils.sha3(rlp.encode([validator_index, epoch, hash, prev_commit_epoch])) v, r, s = utils.ecdsa_raw_sign(sighash, key) sig = utils.encode_int32(v) + utils.encode_int32(r) + utils.encode_int32(s) return rlp.encode([validator_index, epoch, hash, prev_commit_epoch, sig]) def mk_status_flicker(validator_index, epoch, login, key): sighash = utils.sha3(rlp.encode([validator_index, epoch, login])) v, r, s = utils.ecdsa_raw_sign(sighash, key) sig = utils.encode_int32(v) + utils.encode_int32(r) + utils.encode_int32(s) return rlp.encode([validator_index, epoch, login, sig]) # Begin the test print("Starting tests") casper.initiate() # Initialize the first epoch s.state.block_number = EPOCH_LENGTH print('foo', casper.initialize_epoch(1)) assert casper.get_nextValidatorIndex() == 1 start = s.snapshot() print("Epoch initialized") print("Reward factor: %.8f" % (casper.get_reward_factor() * 2 / 3)) # Send a prepare message #configure_logging(config_string=config_string) casper.prepare(mk_prepare(0, 1, '\x35' * 32, '\x00' * 32, 0, '\x00' * 32, t.k0)) print('Gas consumed for a prepare: %d (including %d intrinsic gas)' % (s.state.receipts[-1].gas_used - s.state.receipts[-2].gas_used, s.last_tx.intrinsic_gas_used)) epoch_1_anchash = utils.sha3(b'\x35' * 32 + b'\x00' * 32) assert casper.get_consensus_messages__hash_justified(1, b'\x35' * 32) assert casper.get_consensus_messages__ancestry_hash_justified(1, epoch_1_anchash) print("Prepare message processed") try: casper.prepare(mk_prepare(0, 1, '\x35' * 32, '\x00' * 32, 0, '\x00' * 32, t.k0)) success = True except: success = False assert not success print("Prepare message fails the second time") # Send a commit message casper.commit(mk_commit(0, 1, '\x35' * 32, 0, t.k0)) print('Gas consumed for a commit: %d (including %d intrinsic gas)' % (s.state.receipts[-1].gas_used - s.state.receipts[-2].gas_used, s.last_tx.intrinsic_gas_used)) # Check that we committed assert casper.get_consensus_messages__committed(1) print("Commit message processed") # Initialize the second epoch s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(2) # Check that the dynasty increased as expected assert casper.get_dynasty() == 1 assert casper.get_total_deposits(1) == casper.get_total_deposits(0) > 0 print("Second epoch initialized, dynasty increased as expected") # Send a prepare message casper.prepare(mk_prepare(0, 2, '\x45' * 32, epoch_1_anchash, 1, epoch_1_anchash, t.k0)) # Send a commit message epoch_2_commit = mk_commit(0, 2, '\x45' * 32, 1, t.k0) casper.commit(epoch_2_commit) epoch_2_anchash = utils.sha3(b'\x45' * 32 + epoch_1_anchash) assert casper.get_consensus_messages__ancestry_hash_justified(2, epoch_2_anchash) # Check that we committed assert casper.get_consensus_messages__committed(2) # Initialize the third epoch s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(3) print("Second epoch prepared and committed, third epoch initialized") # Test the NO_DBL_PREPARE slashing condition p1 = mk_prepare(0, 3, '\x56' * 32, epoch_2_anchash, 2, epoch_2_anchash, t.k0) p2 = mk_prepare(0, 3, '\x57' * 32, epoch_2_anchash, 2, epoch_2_anchash, t.k0) snapshot = s.snapshot() casper.double_prepare_slash(p1, p2) s.revert(snapshot) print("NO_DBL_PREPARE slashing condition works") # Test the PREPARE_COMMIT_CONSISTENCY slashing condition p3 = mk_prepare(0, 3, '\x58' * 32, epoch_2_anchash, 0, b'\x00' * 32, t.k0) snapshot = s.snapshot() casper.prepare_commit_inconsistency_slash(p3, epoch_2_commit) s.revert(snapshot) print("PREPARE_COMMIT_CONSISTENCY slashing condition works") # Finish the third epoch casper.prepare(p1) casper.commit(mk_commit(0, 3, '\x56' * 32, 2, t.k0)) epoch_3_anchash = utils.sha3(b'\x56' * 32 + epoch_2_anchash) assert casper.get_consensus_messages__ancestry_hash_justified(3, epoch_3_anchash) assert casper.get_consensus_messages__committed(3) # Initialize the fourth epoch. Not doing prepares or commits during this epoch. s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(4) assert casper.get_dynasty() == 3 epoch_4_anchash = utils.sha3(b'\x67' * 32 + epoch_3_anchash) # Not publishing this prepare for the time being p4 = mk_prepare(0, 4, '\x78' * 32, '\x12' * 32, 3, '\x24' * 32, t.k0) # Initialize the fifth epoch s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(5) print("Epochs up to 5 initialized") # Dynasty not incremented because no commits were made assert casper.get_dynasty() == 3 epoch_5_anchash = utils.sha3(b'\x78' * 32 + epoch_4_anchash) p5 = mk_prepare(0, 5, '\x78' * 32, epoch_4_anchash, 3, epoch_3_anchash, t.k0) casper.prepare(p5) # Test the COMMIT_REQ slashing condition kommit = mk_commit(0, 5, b'\x80' * 32, 3, t.k0) epoch_inc = 1 + int(86400 / 14 / EPOCH_LENGTH) s.state.block_number += EPOCH_LENGTH * epoch_inc print("Speeding up time to test remaining two slashing conditions") for i in range(6, 6 + epoch_inc): casper.initialize_epoch(i) print("Epochs up to %d initialized" % (6 + epoch_inc)) snapshot = s.snapshot() casper.commit_non_justification_slash(kommit) s.revert(snapshot) try: casper.commit_non_justification_slash(0, epoch_2_commit) success = True except: success = False assert not success print("COMMIT_REQ slashing condition works") # Test the PREPARE_REQ slashing condition casper.derive_parenthood(epoch_3_anchash, b'\x67' * 32, epoch_4_anchash) assert casper.get_ancestry(epoch_3_anchash, epoch_4_anchash) == 1 assert casper.get_ancestry(epoch_4_anchash, epoch_5_anchash) == 1 casper.derive_ancestry(epoch_3_anchash, epoch_4_anchash, epoch_5_anchash) assert casper.get_ancestry(epoch_3_anchash, epoch_5_anchash) == 2 snapshot = s.snapshot() casper.prepare_non_justification_slash(p4) s.revert(snapshot) try: casper.prepare_non_justification_slash(p5) success = True except: success = False assert not success print("PREPARE_REQ slashing condition works") print("Restarting the chain for test 2") # Restart the chain s.revert(start) assert casper.get_dynasty() == 0 assert casper.get_current_epoch() == 1 assert casper.get_consensus_messages__ancestry_hash_justified(0, b'\x00' * 32) print("Epoch 1 initialized") for k in (t.k1, t.k2, t.k3, t.k4, t.k5, t.k6): valcode_addr = s.send(t.k0, '', 0, mk_validation_code(utils.privtoaddr(k))) assert utils.big_endian_to_int(s.send(t.k0, purity_checker_address, 0, ct.encode('submit', [valcode_addr]))) == 1 casper.deposit(valcode_addr, utils.privtoaddr(k), value=3 * 10**18) print("Processed 6 deposits") casper.prepare(mk_prepare(0, 1, b'\x10' * 32, b'\x00' * 32, 0, b'\x00' * 32, t.k0)) casper.commit(mk_commit(0, 1, b'\x10' * 32, 0, t.k0)) epoch_1_anchash = utils.sha3(b'\x10' * 32 + b'\x00' * 32) assert casper.get_consensus_messages__committed(1) print("Prepared and committed") s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(2) print("Epoch 2 initialized") assert casper.get_dynasty() == 1 casper.prepare(mk_prepare(0, 2, b'\x20' * 32, epoch_1_anchash, 1, epoch_1_anchash, t.k0)) casper.commit(mk_commit(0, 2, b'\x20' * 32, 1, t.k0)) epoch_2_anchash = utils.sha3(b'\x20' * 32 + epoch_1_anchash) assert casper.get_consensus_messages__committed(2) print("Confirmed that one key is still sufficient to prepare and commit") s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(3) print("Epoch 3 initialized") assert casper.get_dynasty() == 2 assert 3 * 10**18 <= casper.get_total_deposits(0) < 4 * 10**18 assert 3 * 10**18 <= casper.get_total_deposits(1) < 4 * 10**18 assert 21 * 10**18 <= casper.get_total_deposits(2) < 22 * 10**18 print("Confirmed new total_deposits") try: # Try to log out, but sign with the wrong key casper.flick_status(mk_status_flicker(0, 3, 0, t.k1)) success = True except: success = False assert not success # Log out casper.flick_status(mk_status_flicker(4, 3, 0, t.k4)) casper.flick_status(mk_status_flicker(5, 3, 0, t.k5)) casper.flick_status(mk_status_flicker(6, 3, 0, t.k6)) print("Logged out three validators") # Validators leave the fwd validator set in dynasty 4 assert casper.get_validators__dynasty_end(4) == 4 epoch_3_anchash = utils.sha3(b'\x30' * 32 + epoch_2_anchash) # Prepare from one validator casper.prepare(mk_prepare(0, 3, b'\x30' * 32, epoch_2_anchash, 2, epoch_2_anchash, t.k0)) # Not prepared yet assert not casper.get_consensus_messages__hash_justified(3, b'\x30' * 32) print("Prepare from one validator no longer sufficient") # Prepare from 3 more validators for i, k in ((1, t.k1), (2, t.k2), (3, t.k3)): casper.prepare(mk_prepare(i, 3, b'\x30' * 32, epoch_2_anchash, 2, epoch_2_anchash, k)) # Still not prepared assert not casper.get_consensus_messages__hash_justified(3, b'\x30' * 32) print("Prepare from four of seven validators still not sufficient") # Prepare from a fifth validator casper.prepare(mk_prepare(4, 3, b'\x30' * 32, epoch_2_anchash, 2, epoch_2_anchash, t.k4)) # NOW we're prepared! assert casper.get_consensus_messages__hash_justified(3, b'\x30' * 32) print("Prepare from five of seven validators sufficient!") # Five commits for i, k in enumerate([t.k0, t.k1, t.k2, t.k3, t.k4]): casper.commit(mk_commit(i, 3, b'\x30' * 32, 2 if i == 0 else 0, k)) # And we committed! assert casper.get_consensus_messages__committed(3) print("Commit from five of seven validators sufficient") # Start epoch 4 s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(4) assert casper.get_dynasty() == 3 print("Epoch 4 initialized") # Prepare and commit epoch_4_anchash = utils.sha3(b'\x40' * 32 + epoch_3_anchash) for i, k in enumerate([t.k0, t.k1, t.k2, t.k3, t.k4]): casper.prepare(mk_prepare(i, 4, b'\x40' * 32, epoch_3_anchash, 3, epoch_3_anchash, k)) for i, k in enumerate([t.k0, t.k1, t.k2, t.k3, t.k4]): casper.commit(mk_commit(i, 4, b'\x40' * 32, 3, k)) assert casper.get_consensus_messages__committed(4) print("Prepared and committed") # Start epoch 5 / dynasty 4 s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(5) print("Epoch 5 initialized") assert casper.get_dynasty() == 4 assert 21 * 10**18 <= casper.get_total_deposits(3) <= 22 * 10**18 assert 12 * 10**18 <= casper.get_total_deposits(4) <= 13 * 10**18 epoch_5_anchash = utils.sha3(b'\x50' * 32 + epoch_4_anchash) # Do three prepares for i, k in enumerate([t.k0, t.k1, t.k2]): casper.prepare(mk_prepare(i, 5, b'\x50' * 32, epoch_4_anchash, 4, epoch_4_anchash, k)) # Three prepares are insufficient because there are still five validators in the rear validator set assert not casper.get_consensus_messages__hash_justified(5, b'\x50' * 32) print("Three prepares insufficient, as rear validator set still has seven") # Do two more prepares for i, k in [(3, t.k3), (4, t.k4)]: casper.prepare(mk_prepare(i, 5, b'\x50' * 32, epoch_4_anchash, 4, epoch_4_anchash, k)) # Now we're good! assert casper.get_consensus_messages__hash_justified(5, b'\x50' * 32) print("Five prepares sufficient") for i, k in enumerate([t.k0, t.k1, t.k2, t.k3, t.k4]): casper.commit(mk_commit(i, 5, b'\x50' * 32, 4, k)) # Committed! assert casper.get_consensus_messages__committed(5) # Start epoch 6 / dynasty 5 s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(6) assert casper.get_dynasty() == 5 print("Epoch 6 initialized") # Log back in old_deposit_start = casper.get_dynasty_start_epoch(casper.get_validators__dynasty_start(4)) old_deposit_end = casper.get_dynasty_start_epoch(casper.get_validators__dynasty_end(4) + 1) old_deposit = casper.get_validators__deposit(4) # Explanation: # * During dynasty 0, the validator deposited, so he joins the current set in dynasty 2 # (epoch 3), and the previous set in dynasty 3 (epoch 4) # * During dynasty 2, the validator logs off, so he leaves the current set in dynasty 4 # (epoch 5) and the previous set in dynasty 5 (epoch 6) assert [casper.check_eligible_in_epoch(4, i) for i in range(7)] == [0, 0, 0, 2, 3, 1, 0] casper.flick_status(mk_status_flicker(4, 6, 1, t.k4)) # Explanation: # * During dynasty 7, the validator will log on again. Hence, the dynasty mask # should include dynasties 4, 5, 6 assert [casper.check_eligible_in_epoch(4, i) for i in range(7)] == [0, 0, 0, 2, 3, 1, 0] new_deposit = casper.get_validators__deposit(4) print("One validator logging back in") print("Penalty from %d epochs: %.4f" % (old_deposit_end - old_deposit_start, 1 - new_deposit / old_deposit)) assert casper.get_validators__dynasty_start(4) == 7 # Here three prepares and three commits should be sufficient! epoch_6_anchash = utils.sha3(b'\x60' * 32 + epoch_5_anchash) for i, k in enumerate([t.k0, t.k1, t.k2]): casper.prepare(mk_prepare(i, 6, b'\x60' * 32, epoch_5_anchash, 5, epoch_5_anchash, k)) for i, k in enumerate([t.k0, t.k1, t.k2]): casper.commit(mk_commit(i, 6, b'\x60' * 32, 5, k)) assert casper.get_consensus_messages__committed(6) print("Three of four prepares and commits sufficient") # Start epoch 7 / dynasty 6 s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(7) assert casper.get_dynasty() == 6 print("Epoch 7 initialized") # Here three prepares and three commits should be sufficient! epoch_7_anchash = utils.sha3(b'\x70' * 32 + epoch_6_anchash) for i, k in enumerate([t.k0, t.k1, t.k2]): #if i == 1: # configure_logging(config_string=config_string) casper.prepare(mk_prepare(i, 7, b'\x70' * 32, epoch_6_anchash, 6, epoch_6_anchash, k)) #if i == 1: # import sys # sys.exit() print('Gas consumed for first prepare', s.state.receipts[-1].gas_used - s.state.receipts[-2].gas_used) print('Gas consumed for second prepare', s.state.receipts[-2].gas_used - s.state.receipts[-3].gas_used) print('Gas consumed for third prepare', s.state.receipts[-3].gas_used - s.state.receipts[-4].gas_used) for i, k in enumerate([t.k0, t.k1, t.k2]): casper.commit(mk_commit(i, 7, b'\x70' * 32, 6, k)) print('Gas consumed for first commit', s.state.receipts[-1].gas_used - s.state.receipts[-2].gas_used) print('Gas consumed for second commit', s.state.receipts[-2].gas_used - s.state.receipts[-3].gas_used) print('Gas consumed for third commit', s.state.receipts[-3].gas_used - s.state.receipts[-4].gas_used) assert casper.get_consensus_messages__committed(7) print("Three of four prepares and commits sufficient") # Start epoch 8 / dynasty 7 s.state.block_number += EPOCH_LENGTH casper.initialize_epoch(8) assert casper.get_dynasty() == 7 print("Epoch 8 initialized") assert 12 * 10**18 <= casper.get_total_deposits(6) <= 13 * 10**18 assert 15 * 10**18 <= casper.get_total_deposits(7) <= 16 * 10**18 epoch_8_anchash = utils.sha3(b'\x80' * 32 + epoch_7_anchash) # Do three prepares for i, k in enumerate([t.k0, t.k1, t.k2]): casper.prepare(mk_prepare(i, 8, b'\x80' * 32, epoch_7_anchash, 7, epoch_7_anchash, k)) # Three prepares are insufficient because there are still five validators in the rear validator set assert not casper.get_consensus_messages__hash_justified(8, b'\x80' * 32) print("Three prepares no longer sufficient, as the forward validator set has five validators") # Do one more prepare for i, k in [(3, t.k3)]: casper.prepare(mk_prepare(i, 8, b'\x80' * 32, epoch_7_anchash, 7, epoch_7_anchash, k)) # Now we're good! assert casper.get_consensus_messages__hash_justified(8, b'\x80' * 32) print("Four of five prepares sufficient") for i, k in enumerate([t.k0, t.k1, t.k2, t.k3, t.k4]): casper.commit(mk_commit(i, 8, b'\x80' * 32, 7 if i < 3 else 5, k)) assert casper.get_consensus_messages__committed(8) print("Committed") # Validator rejoins current validator set in epoch 8 assert [casper.check_eligible_in_epoch(4, i) for i in range(9)] == [0, 0, 0, 2, 3, 1, 0, 0, 2] print("All tests passed")