Update RPC tests for Dogecoin (#1431)

* Make most of the RPC tests pass
* Add AUXPoW rpc tests
- Tests the auxpow rpc interface `getauxblock`
- Tests consensus constraints for auxpow:
  - Minimum block height
  - Valid scrypt proof of work
  - Foreign chain ID

1 files changed, 104 insertions, 0 deletions

diff --git a/qa/rpc-tests/test_framework/scrypt_auxpow.py b/qa/rpc-tests/test_framework/scrypt_auxpow.py
new file mode 100644
index 000000000..1e95a5820
--- /dev/null
+++ b/qa/rpc-tests/test_framework/scrypt_auxpow.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python
+# Copyright (c) 2014 Daniel Kraft
+# Copyright (c) 2015-2018 The Dogecoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+# General code for scrypt auxpow testing.  This includes routines to
+# solve an auxpow header and to generate auxpow blocks with scrypt.
+# extends and modifies auxpow module by Daniel Kraft.
+
+# This module requires a built and installed version of the ltc_scrypt
+# package, which can be downloaded from:
+# https://pypi.python.org/packages/source/l/ltc_scrypt/ltc_scrypt-1.0.tar.gz
+
+from .auxpow import *
+import ltc_scrypt
+
+def computeAuxpowWithChainId (block, target, chainid, ok):
+  """
+  Build an auxpow object (serialised as hex string) that solves the
+  block, for a given chain id.
+  """
+
+  # Start by building the merge-mining coinbase.  The merkle tree
+  # consists only of the block hash as root.
+  coinbase = "fabe" + (b"m" * 2).hex()
+  coinbase += block
+  coinbase += "01000000" + ("00" * 4)
+
+  # Construct "vector" of transaction inputs.
+  vin = "01"
+  vin += ("00" * 32) + ("ff" * 4)
+  vin += ("%02x" % int(len (coinbase) / 2)) + coinbase
+  vin += ("ff" * 4)
+
+  # Build up the full coinbase transaction.  It consists only
+  # of the input and has no outputs.
+  tx = "01000000" + vin + "00" + ("00" * 4)
+  txHash = doubleHashHex (tx)
+
+  # Construct the parent block header.  It need not be valid, just good
+  # enough for auxpow purposes.
+  header = "0100" + chainid + "00"
+  header += "00" * 32
+  header += reverseHex (txHash)
+  header += "00" * 4
+  header += "00" * 4
+  header += "00" * 4
+
+  # Mine the block.
+  (header, blockhash) = mineScryptBlock (header, target, ok)
+
+  # Build the MerkleTx part of the auxpow.
+  output = tx
+  output += blockhash
+  output += "00"
+  output += "00" * 4
+
+  # Extend to full auxpow.
+  output += "00"
+  output += "00" * 4
+  output += header
+
+  return output
+
+# for now, just offer hashes to rpc until it matches the work we need
+def mineScryptAux (node, chainid, ok):
+  """
+  Mine an auxpow block on the given RPC connection.
+  """
+
+  auxblock = node.getauxblock ()
+  target = reverseHex (auxblock['_target'])
+
+  apow = computeAuxpowWithChainId (auxblock['hash'], target, chainid, ok)
+  res = node.getauxblock (auxblock['hash'], apow)
+  return res
+
+def mineScryptBlock (header, target, ok):
+  """
+  Given a block header, update the nonce until it is ok (or not)
+  for the given target.
+  """
+
+  data = bytearray (bytes.fromhex(header))
+  while True:
+    assert data[79] < 255
+    data[79] += 1
+    hexData = data.hex()
+
+    scrypt = getScryptPoW(hexData)
+    if (ok and scrypt < target) or ((not ok) and scrypt > target):
+      break
+
+  blockhash = doubleHashHex (hexData)
+  return (hexData, blockhash)
+
+def getScryptPoW(hexData):
+  """
+  Actual scrypt pow calculation
+  """
+
+  data = bytes.fromhex(hexData)
+  return reverseHex(ltc_scrypt.getPoWHash(data).hex())