nimbus-eth1/nimbus_verified_proxy/validate_proof.nim

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# nimbus_verified_proxy
# Copyright (c) 2022-2023 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [].}
import
std/[sequtils, typetraits, options],
stint,
stew/results,
eth/common/eth_types as etypes,
eth/common/eth_types_rlp,
eth/rlp,
eth/trie/[hexary, hexary_proof_verification],
web3/ethtypes
export results
func toMDigest(arg: FixedBytes[32]): MDigest[256] =
MDigest[256](data: distinctBase(arg))
func emptyAccount(): etypes.Account =
return etypes.Account(
nonce: uint64(0),
balance: UInt256.zero,
storageRoot: etypes.EMPTY_ROOT_HASH,
codeHash: etypes.EMPTY_CODE_HASH
)
proc isValidProof(
branch: seq[seq[byte]],
rootHash: KeccakHash,
key, value: seq[byte]): bool =
try:
# TODO: Investigate if this handles proof of non-existence.
# Probably not as bool is not expressive enough to say if proof is valid,
# but key actually does not exists in MPT
return isValidBranch(branch, rootHash, key, value)
except RlpError:
return false
proc getAccountFromProof*(
stateRoot: FixedBytes[32],
accountAddress: Address,
accountBalance: UInt256,
accountNonce: Quantity,
accountCodeHash: CodeHash,
accountStorageRootHash: StorageHash,
mptNodes: seq[RlpEncodedBytes]
): Result[etypes.Account, string] =
let
mptNodesBytes = mptNodes.mapIt(distinctBase(it))
keccakStateRootHash = toMDigest(stateRoot)
acc = etypes.Account(
nonce: distinctBase(accountNonce),
balance: accountBalance,
storageRoot: toMDigest(accountStorageRootHash),
codeHash: toMDigest(accountCodeHash)
)
accountEncoded = rlp.encode(acc)
accountKey = toSeq(keccakHash(distinctBase(accountAddress)).data)
let proofResult = verifyMptProof(
mptNodesBytes,
keccakStateRootHash,
accountKey,
accountEncoded
)
case proofResult.kind
of MissingKey:
return ok(emptyAccount())
of ValidProof:
return ok(acc)
of InvalidProof:
return err(proofResult.errorMsg)
proc getStorageData(
account: etypes.Account,
storageProof: StorageProof): Result[UInt256, string] =
let
storageMptNodes = storageProof.proof.mapIt(distinctBase(it))
key = toSeq(keccakHash(toBytesBE(storageProof.key)).data)
encodedValue = rlp.encode(storageProof.value)
proofResult = verifyMptProof(
storageMptNodes, account.storageRoot, key, encodedValue)
case proofResult.kind
of MissingKey:
return ok(UInt256.zero)
of ValidProof:
return ok(storageProof.value)
of InvalidProof:
return err(proofResult.errorMsg)
proc getStorageData*(
stateRoot: FixedBytes[32],
requestedSlot: UInt256,
proof: ProofResponse): Result[UInt256, string] =
let account = ?getAccountFromProof(
stateRoot,
proof.address,
proof.balance,
proof.nonce,
proof.codeHash,
proof.storageHash,
proof.accountProof
)
if account.storageRoot == etypes.EMPTY_ROOT_HASH:
# valid account with empty storage, in that case getStorageAt
# return 0 value
return ok(u256(0))
if len(proof.storageProof) != 1:
return err("no storage proof for requested slot")
let sproof = proof.storageProof[0]
if len(sproof.proof) == 0:
return err("empty mpt proof for account with not empty storage")
if sproof.key != requestedSlot:
return err("received proof for invalid slot")
return getStorageData(account, sproof)
2022-11-21 12:28:15 +00:00
func isValidCode*(account: etypes.Account, code: openArray[byte]): bool =
return account.codeHash == keccakHash(code)