nimbus-eth2/nfuzz/libnfuzz.nim

170 lines
6.6 KiB
Nim

# Required for deserialisation of ValidatorSig in Attestation due to
# https://github.com/nim-lang/Nim/issues/11225
import
stew/ptrops, stew/ranges/ptr_arith, chronicles,
../beacon_chain/extras,
../beacon_chain/spec/[crypto, datatypes, digest, validator, beaconstate,
state_transition_block, state_transition],
../beacon_chain/ssz/[merkleization, ssz_serialization]
type
AttestationInput = object
state: BeaconState
attestation: Attestation
AttesterSlashingInput = object
state: BeaconState
attesterSlashing: AttesterSlashing
BlockInput = object
state: BeaconState
beaconBlock: SignedBeaconBlock
BlockHeaderInput = BlockInput
DepositInput = object
state: BeaconState
deposit: Deposit
ProposerSlashingInput = object
state: BeaconState
proposerSlashing: ProposerSlashing
VoluntaryExitInput = object
state: BeaconState
exit: SignedVoluntaryExit
# This and AssertionError are raised to indicate programming bugs
# A wrapper to allow exception tracking to identify unexpected exceptions
FuzzCrashError = object of CatchableError
# TODO: change ptr uint to ptr csize_t when available in newer Nim version.
proc copyState(state: BeaconState, xoutput: ptr byte,
xoutput_size: ptr uint): bool {.raises: [FuzzCrashError, Defect].} =
var resultState =
try:
SSZ.encode(state)
except IOError as e:
# Shouldn't occur as the writer isn't a file
raise newException(FuzzCrashError, "Unexpected failure to serialize.", e)
if unlikely(resultState.len.uint > xoutput_size[]):
let msg = (
"Not enough xoutput buffer provided to nimbus harness. Provided: " &
$(xoutput_size[]) &
"Required: " &
$resultState.len.uint
)
raise newException(FuzzCrashError, msg)
xoutput_size[] = resultState.len.uint
# TODO: improvement might be to write directly to buffer with xoutputStream
# and SszWriter (but then need to ensure length doesn't overflow)
copyMem(xoutput, unsafeAddr resultState[0], xoutput_size[])
result = true
template decodeAndProcess(typ, process: untyped): bool =
let flags {.inject.} = if disable_bls: {skipBlsValidation} else: {}
var
cache {.used, inject.} = get_empty_per_epoch_cache()
data {.inject.} = newClone(
try:
SSZ.decode(input, typ)
except MalformedSszError as e:
raise newException(
FuzzCrashError,
"Malformed SSZ, likely bug in preprocessing.", e)
except SszSizeMismatchError as e:
raise newException(
FuzzCrashError,
"SSZ size mismatch, likely bug in preprocessing.", e)
)
let processOk =
try:
process
except IOError as e:
raise newException(
FuzzCrashError, "Unexpected (logging?) IOError in state transition", e,
)
except ValueError as e:
raise newException(
FuzzCrashError,
"Unexpected (logging?) IOError in state transition", e)
except Exception as e:
# TODO why an Exception?
# Lots of vendor code looks like it might raise a bare exception type
raise newException(FuzzCrashError, "Unexpected Exception in state transition", e)
if processOk:
copyState(data.state, xoutput, xoutput_size)
else:
false
proc nfuzz_attestation(input: openArray[byte], xoutput: ptr byte,
xoutput_size: ptr uint, disable_bls: bool): bool {.exportc, raises: [FuzzCrashError, Defect].} =
decodeAndProcess(AttestationInput):
process_attestation(data.state, data.attestation, flags, cache)
proc nfuzz_attester_slashing(input: openArray[byte], xoutput: ptr byte,
xoutput_size: ptr uint, disable_bls: bool): bool {.exportc, raises: [FuzzCrashError, Defect].} =
decodeAndProcess(AttesterSlashingInput):
process_attester_slashing(data.state, data.attesterSlashing, flags, cache)
proc nfuzz_block(input: openArray[byte], xoutput: ptr byte,
xoutput_size: ptr uint, disable_bls: bool): bool {.exportc, raises: [FuzzCrashError, Defect].} =
# There's not a perfect approach here, but it's not worth switching the rest
# and requiring HashedBeaconState (yet). So to keep consistent, puts wrapper
# only in one function.
proc state_transition(
data: auto, blck: auto, flags: auto, rollback: RollbackHashedProc):
auto =
var hashedState =
HashedBeaconState(data: data.state, root: hash_tree_root(data.state))
result = state_transition(hashedState, blck, flags, rollback)
data.state = hashedState.data
decodeAndProcess(BlockInput):
state_transition(data, data.beaconBlock, flags, noRollback)
proc nfuzz_block_header(input: openArray[byte], xoutput: ptr byte,
xoutput_size: ptr uint, disable_bls: bool): bool {.exportc, raises: [FuzzCrashError, Defect].} =
decodeAndProcess(BlockHeaderInput):
process_block_header(data.state, data.beaconBlock.message, flags, cache)
proc nfuzz_deposit(input: openArray[byte], xoutput: ptr byte,
xoutput_size: ptr uint, disable_bls: bool): bool {.exportc, raises: [FuzzCrashError, Defect].} =
decodeAndProcess(DepositInput):
process_deposit(data.state, data.deposit, flags)
proc nfuzz_proposer_slashing(input: openArray[byte], xoutput: ptr byte,
xoutput_size: ptr uint, disable_bls: bool): bool {.exportc, raises: [FuzzCrashError, Defect].} =
decodeAndProcess(ProposerSlashingInput):
process_proposer_slashing(data.state, data.proposerSlashing, flags, cache)
proc nfuzz_voluntary_exit(input: openArray[byte], xoutput: ptr byte,
xoutput_size: ptr uint, disable_bls: bool): bool {.exportc, raises: [FuzzCrashError, Defect].} =
decodeAndProcess(VoluntaryExitInput):
process_voluntary_exit(data.state, data.exit, flags)
# Note: Could also accept raw input pointer and access list_size + seed here.
# However, list_size needs to be known also outside this proc to allocate xoutput.
# TODO: rework to copy immediatly in an uint8 openArray, considering we have to
# go over the list anyhow?
proc nfuzz_shuffle(input_seed: ptr byte, xoutput: var openArray[uint64]): bool
{.exportc, raises: [Defect].} =
var seed: Eth2Digest
# Should be OK as max 2 bytes are passed by the framework.
let list_size = xoutput.len.uint64
copyMem(addr(seed.data), input_seed, sizeof(seed.data))
var shuffled_seq: seq[ValidatorIndex]
shuffled_seq = get_shuffled_seq(seed, list_size)
doAssert(
list_size == shuffled_seq.len.uint64,
"Shuffled list should be of requested size."
)
for i in 0..<list_size:
# ValidatorIndex is currently wrongly uint32 so we copy this 1 by 1,
# assumes passed xoutput is zeroed.
copyMem(offset(addr xoutput, i.int), shuffled_seq[i.int].unsafeAddr,
sizeof(ValidatorIndex))
result = true