Tests for zmqpubrawtx and zmqpubrawblock

Github-Pull: #10552
Rebased-From: d3677ab757

test/functional/test_framework/util.py

@@ -7,6 +7,7 @@
 from base64 import b64encode
 from binascii import hexlify, unhexlify
 from decimal import Decimal, ROUND_DOWN
+import hashlib
 import json
 import logging
 import os
@@ -173,6 +174,13 @@ def count_bytes(hex_string):
 def bytes_to_hex_str(byte_str):
     return hexlify(byte_str).decode('ascii')
 
+def hash256(byte_str):
+    sha256 = hashlib.sha256()
+    sha256.update(byte_str)
+    sha256d = hashlib.sha256()
+    sha256d.update(sha256.digest())
+    return sha256d.digest()[::-1]
+
 def hex_str_to_bytes(hex_str):
     return unhexlify(hex_str.encode('ascii'))