nimbus-eth1/nimbus/evm/interpreter/op_handlers/oph_hash.nim

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# Nimbus
# Copyright (c) 2018 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed except
# according to those terms.
## EVM Opcode Handlers: Hashes
## ===========================
##
import
../../../constants,
../../../errors,
../../computation,
../../memory,
../../stack,
../gas_costs,
../op_codes,
../utils/utils_numeric,
./oph_defs,
eth/common
{.push raises: [CatchableError].} # basically the annotation type of a `Vm2OpFn`
# ------------------------------------------------------------------------------
# Private, op handlers implementation
# ------------------------------------------------------------------------------
const
sha3Op: Vm2OpFn = proc (k: var Vm2Ctx) =
## 0x20, Compute Keccak-256 hash.
let (startPos, length) = k.cpt.stack.popInt(2)
let (pos, len) = (startPos.safeInt, length.safeInt)
if pos < 0 or len < 0 or pos > 2147483648'i64:
raise newException(OutOfBoundsRead, "Out of bounds memory access")
k.cpt.opcodeGastCost(Op.Sha3,
k.cpt.gasCosts[Op.Sha3].m_handler(k.cpt.memory.len, pos, len),
reason = "SHA3: word gas cost")
k.cpt.memory.extend(pos, len)
let endRange = min(pos + len, k.cpt.memory.len) - 1
if endRange == -1 or pos >= k.cpt.memory.len:
k.cpt.stack.push(EMPTY_SHA3)
else:
k.cpt.stack.push:
keccakHash k.cpt.memory.bytes.toOpenArray(pos, endRange)
# ------------------------------------------------------------------------------
# Public, op exec table entries
# ------------------------------------------------------------------------------
const
vm2OpExecHash*: seq[Vm2OpExec] = @[
(opCode: Op.Sha3, ## 0x20, Keccak-256
forks: Vm2OpAllForks,
name: "sha3",
info: "Compute Keccak-256 hash",
exec: (prep: vm2OpIgnore,
run: sha3Op,
post: vm2OpIgnore))]
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------