update bench for modexp (#265)

mratsim · Sep 6, 2023 · b645d68 · b645d68
1 parent c85ffb0
commit b645d68
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Showing 2 changed files with 206 additions and 11 deletions.
diff --git a/benchmarks/bench_evm_modexp_dos.nim b/benchmarks/bench_evm_modexp_dos.nim
@@ -1,8 +1,9 @@
 import
   ../constantine/ethereum_evm_precompiles,
-  ./platforms, ./bench_blueprint,
-
-  ../constantine/serialization/codecs
+  ../constantine/math/arithmetic,
+  ../constantine/math/io/io_bigints,
+  ../constantine/platforms/abstractions,
+  ./platforms, ./bench_blueprint
 
 proc report(op: string, elapsedNs: int64, elapsedCycles: int64, iters: int) =
   let ns = elapsedNs div iters
@@ -24,11 +25,88 @@ template bench(fnCall: untyped, ticks, ns: var int64): untyped =
     ticks += stopClock - startClock
     ns += inNanoseconds(stopTime-startTime)
 
-proc main() =
+func computeGasFee(inputs: openArray[byte]): tuple[eip128, eip2565: int] =
+  ## Note: This is an approximation
+  # For Denial-of-Service fuzzing we want to ensure that
+  # 30M gas blocks are processed in a few milliseconds at most
+  # https://eips.ethereum.org/EIPS/eip-198
+  # https://eips.ethereum.org/EIPS/eip-2565
+  func mulComplexityEIP198(x: int): int =
+    ## Estimates the difficulty of Karatsuba multiplication
+    if x <= 64: x * x
+    elif x <= 1024: (x * x) div 4 + 96*x - 3072
+    else: (x * x) div 16 + 480*x - 199680
+
+  func mulComplexityEIP2565(x: int): int =
+    result = (x+7) div 8
+    result *= result
+
+  func getMSB_bigEndian(a: openArray[byte]): int =
+    ## Returns the position of the most significant bit
+    ## of `a`.
+    ## Returns 0 if a == 0
+    ##
+    ## a is stored in bigEndian representation
+    result = 0
+    for i in 0 ..< a.len:
+      if a[i] != byte(0):
+        return int(log2_vartime(uint32 a[i])) + 8*(a.len-1-i)
+
+  func iterCount(exponent: openArray[byte]): int =
+    let msbFirst32Bits = exponent.toOpenArray(0, min(exponent.len, 32) - 1).getMSB_bigEndian()
+
+    if exponent.len <= 32:
+      result = msbFirst32Bits
+    else:
+      result = (8*(exponent.len-32)) + msbFirst32Bits
+    if result < 1:
+      result = 1
+
+  func gasCostEIP198(baseLen, modLen: int, exponent: openArray[byte]): int =
+    const Gquaddivisor = 20
+    let mulComplexity = mulComplexityEIP198(max(baseLen, modLen))
+    let adjExpLen = iterCount(exponent)
+
+    return (mulComplexity * max(adjExpLen, 1)) div Gquaddivisor
+
+  func gasCostEIP2565(baseLen, modLen: int, exponent: openArray[byte]): int =
+    const Gquaddivisor = 3
+    let mulComplexity = mulComplexityEIP2565(max(baseLen, modLen))
+    let iterCount = iterCount(exponent)
+
+    return max(200, (mulComplexity * iterCount) div Gquaddivisor)
+
+  # Input parse sizes
+  # -----------------
+  let
+    bL = BigInt[256].unmarshal(inputs.toOpenArray(0, 31), bigEndian)
+    eL = BigInt[256].unmarshal(inputs.toOpenArray(32, 63), bigEndian)
+    mL = BigInt[256].unmarshal(inputs.toOpenArray(64, 95), bigEndian)
+
+    baseByteLen = cast[int](bL.limbs[0])
+    exponentByteLen = cast[int](eL.limbs[0])
+    modulusByteLen = cast[int](mL.limbs[0])
+
+    baseStart = 96
+    baseStop  = baseStart+baseByteLen-1
+    expStart  = baseStop+1
+    expStop   = expStart+exponentByteLen-1
+    modStart  = expStop+1
+    modStop   = modStart+modulusByteLen-1
+
+  template exponent(): untyped =
+    inputs.toOpenArray(expStart, expStop)
+
+  let gasFeeEIP198 = gasCostEIP198(baseByteLen, modulusByteLen, exponent)
+  let gasFeeEIP2565 = gasCostEIP2565(baseByteLen, modulusByteLen, exponent)
+
+  return (gasFeeEIP198, gasFeeEIP2565)
+
+proc dos1() =
 
   let input = [
       # Length of base (32)
-      (uint8)0x00,
+      uint8 0x00,
             0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20,
 
@@ -56,14 +134,131 @@ proc main() =
   var r = newSeq[byte](32)
   var ticks, nanoseconds: int64
 
-  const Iters = 22058
+  let (gasFeeEIP198, gasFeeEIP2565) = computeGasFee(input)
+  const blockSize = 30000000
+
+  let execsEIP198 = blockSize div gasFeeEIP198
+  let execsEIP2565 = blockSize div gasFeeEIP2565
+
+  echo "Gas cost: ", gasFeeEIP198, " gas (EIP-198) - ", execsEIP198, " executions per block"
+  echo "Gas cost: ", gasFeeEIP2565, " gas (EIP-2565) - ", execsEIP2565, " executions per block"
 
-  for i in 0 ..< Iters:
+  for i in 0 ..< execsEIP2565:
       bench(
         (let _ = r.eth_evm_modexp(input)),
         ticks, nanoseconds)
 
-  report("EVM Modexp", nanoseconds, ticks, Iters)
-  echo "Total time: ", nanoseconds.float64 / 1e6, " ms"
+  report("EVM Modexp - 32,32,32", nanoseconds, ticks, execsEIP2565)
+  echo "Total time: ", nanoseconds.float64 / 1e6, " ms for ", execsEIP2565, " iterations"
+
+proc dos2() =
+
+  let input = [
+    # Length of base (1)
+    uint8 0x00,
+          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+
+    # Length of exponent (1)
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+
+    # Length of modulus (121)
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79,
+
+    # Base
+    0x33,
+
+    # Exponent
+    0x10,
+
+    # Modulus
+    0x04, 0xea, 0xbb, 0x12, 0x55, 0x88, 0xd7, 0x3c, 0xad, 0x22, 0xea, 0x2b, 0x4a, 0x77, 0x6e, 0x9d,
+    0x4d, 0xfc, 0x13, 0xa8, 0x1b, 0xf9, 0x0c, 0x0d, 0x37, 0xe8, 0x4e, 0x8b, 0xeb, 0xb2, 0xa5, 0x48,
+    0x8b, 0x2c, 0x87, 0x6d, 0x13, 0x51, 0x75, 0xeb, 0x97, 0xc6, 0x13, 0xd9, 0x06, 0xce, 0x8b, 0x53,
+    0xd0, 0x02, 0x68, 0xb8, 0xd6, 0x12, 0xab, 0x8b, 0x15, 0x0c, 0xef, 0x0a, 0xd0, 0x3b, 0x73, 0xd2,
+    0xdb, 0x9d, 0x2a, 0xa5, 0x23, 0x70, 0xdc, 0x26, 0x55, 0x80, 0xca, 0xf2, 0xc0, 0x18, 0xe3, 0xe3,
+    0x1b, 0xad, 0xd5, 0x22, 0xdd, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x1c, 0x05, 0x71, 0x52, 0x7c, 0x3a, 0xb0, 0x77,
+  ]
+
+  var r = newSeq[byte](121)
+  var ticks, nanoseconds: int64
+
+  let (gasFeeEIP198, gasFeeEIP2565) = computeGasFee(input)
+  const blockSize = 30000000
+
+  let execsEIP198 = blockSize div gasFeeEIP198
+  let execsEIP2565 = blockSize div gasFeeEIP2565
+
+  echo "Gas cost: ", gasFeeEIP198, " gas (EIP-198) - ", execsEIP198, " executions per block"
+  echo "Gas cost: ", gasFeeEIP2565, " gas (EIP-2565) - ", execsEIP2565, " executions per block"
+
+  for i in 0 ..< execsEIP2565:
+      bench(
+        (let _ = r.eth_evm_modexp(input)),
+        ticks, nanoseconds)
+
+  report("EVM Modexp - 1,1,121", nanoseconds, ticks, execsEIP2565)
+  echo "Total time: ", nanoseconds.float64 / 1e6, " ms for ", execsEIP2565, " iterations"
+
+proc dos3() =
+
+  let input = [
+    # Length of base (1)
+    uint8 0x00,
+          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+
+    # Length of exponent (1)
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+
+    # Length of modulus (121)
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79,
+
+    # Base
+    0x33,
+
+    # Exponent
+    0x07,
+
+    # Modulus
+    0x04, 0xea, 0xbb, 0x12, 0x55, 0x88, 0xd7, 0x3c, 0xad, 0x22, 0xea, 0x2b, 0x4a, 0x77, 0x6e, 0x9d,
+    0x4d, 0xfc, 0x13, 0xa8, 0x1b, 0xf9, 0x0c, 0x0d, 0x37, 0xe8, 0x4e, 0x8b, 0xeb, 0xb2, 0xa5, 0x48,
+    0x8b, 0x2c, 0x87, 0x6d, 0x13, 0x51, 0x75, 0xeb, 0x97, 0xc6, 0x13, 0xd9, 0x06, 0xce, 0x8b, 0x53,
+    0xd0, 0x02, 0x68, 0xb8, 0xd6, 0x12, 0xab, 0x8b, 0x15, 0x0c, 0xef, 0x0a, 0xd0, 0x3b, 0x73, 0xd2,
+    0xdb, 0x9d, 0x2a, 0xa5, 0x23, 0x70, 0xdc, 0x26, 0x55, 0x80, 0xca, 0xf2, 0xc0, 0x18, 0xe3, 0xe3,
+    0x1b, 0xad, 0xd5, 0x22, 0xdd, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x1c, 0x05, 0x71, 0x52, 0x7c, 0x3a, 0xb0, 0x77,
+  ]
+
+  var r = newSeq[byte](121)
+  var ticks, nanoseconds: int64
+
+  let (gasFeeEIP198, gasFeeEIP2565) = computeGasFee(input)
+  const blockSize = 30000000
+
+  let execsEIP198 = blockSize div gasFeeEIP198
+  let execsEIP2565 = blockSize div gasFeeEIP2565
+
+  echo "Gas cost: ", gasFeeEIP198, " gas (EIP-198) - ", execsEIP198, " executions per block"
+  echo "Gas cost: ", gasFeeEIP2565, " gas (EIP-2565) - ", execsEIP2565, " executions per block"
+
+  for i in 0 ..< execsEIP2565:
+    bench(
+      (let _ = r.eth_evm_modexp(input)),
+      ticks, nanoseconds)
+
+  report("EVM Modexp - 1,1,121", nanoseconds, ticks, execsEIP2565)
+  echo "Total time: ", nanoseconds.float64 / 1e6, " ms for ", execsEIP2565, " iterations"
 
-main()
+dos1()
+echo "\n"
+dos2()
+echo "\n"
+dos3()
diff --git a/constantine/math_arbitrary_precision/arithmetic/limbs_views.nim b/constantine/math_arbitrary_precision/arithmetic/limbs_views.nim
@@ -111,7 +111,7 @@ func getMSB_vartime*[T](a: openArray[T]): int =
   ## Returns -1 if a == 0
   result = -1
   for i in countdown(a.len-1, 0):
-    if bool a[i] != T(0):
+    if bool(a[i] != T(0)):
       return int(log2_vartime(uint64 a[i])) + 8*sizeof(T)*i
 
 func getBits_vartime*[T](a: openArray[T]): int {.inline.} =