nimbus-eth1/nimbus/vm2/interpreter/op_handlers/oph_hash.nim

126 lines
3.9 KiB
Nim

# 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
## ===========================
##
const
kludge {.intdefine.}: int = 0
breakCircularDependency {.used.} = kludge > 0
import
../../../errors,
./oph_defs,
stint
# ------------------------------------------------------------------------------
# Kludge BEGIN
# ------------------------------------------------------------------------------
when not breakCircularDependency:
import
../../../constants,
../../stack,
../../v2computation,
../../v2memory,
../gas_meter,
../utils/v2utils_numeric,
../v2gas_costs,
eth/common,
nimcrypto
else:
import macros
var blindGasCosts: array[Op,int]
# copied from stack.nim
macro genTupleType(len: static[int], elemType: untyped): untyped =
result = nnkTupleConstr.newNimNode()
for i in 0 ..< len: result.add(elemType)
# function stubs from stack.nim (to satisfy compiler logic)
proc push[T](x: Stack; n: T) = discard
proc popInt(x: var Stack, n: static[int]): auto =
var rc: genTupleType(n, UInt256)
return rc
# function stubs from v2utils_numeric.nim
func safeInt(x: Uint256): int = discard
# function stubs from v2memory.nim
proc len(mem: Memory): int = 0
proc extend(mem: var Memory; startPos: Natural; size: Natural) = discard
# function stubs from v2computation.nim (to satisfy compiler logic)
proc gasCosts(c: Computation): array[Op,int] = blindGasCosts
# function stubs from gas_meter.nim
proc consumeGas(gasMeter: var GasMeter; amount: int; reason: string) = discard
# dummy stubs from constants
const EMPTY_SHA3 = 0xdeadbeef.u256
# function stubs from nimcrypto/hash.nim and nimcrypto/keccak.nim
const keccak256 = 0xfeedbeef
proc digest(dummy: int64, data: openarray[byte]): UInt256 = EMPTY_SHA3
# stubs from v2gas_costs.nim
proc m_handler(x: int; curMemSize, memOffset, memLen: int64): int = 0
# ------------------------------------------------------------------------------
# Kludge END
# ------------------------------------------------------------------------------
# ------------------------------------------------------------------------------
# Private, op handlers implementation
# ------------------------------------------------------------------------------
const
sha3Op: Vm2OpFn = proc (k: 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.gasMeter.consumeGas(
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:
keccak256.digest k.cpt.memory.bytes.toOpenArray(pos, endRange)
# ------------------------------------------------------------------------------
# Public, op exec table entries
# ------------------------------------------------------------------------------
const
vm2OpExecHash*: seq[Vm2OpExec] = @[
(opCode: Op.Sha3, ## 0x20, Keccak-256
forks: Vm2OpAllForks,
info: "Compute Keccak-256 hash",
exec: (prep: vm2OpIgnore,
run: sha3Op,
post: vm2OpIgnore))]
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------