diff --git a/test/functional/test_framework/address.py b/test/functional/test_framework/address.py
--- a/test/functional/test_framework/address.py
+++ b/test/functional/test_framework/address.py
@@ -4,8 +4,10 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Encode and decode BASE58, P2PKH and P2SH addresses."""
 
+import unittest
+
 from .script import CScript, hash160, hash256
-from .util import hex_str_to_bytes
+from .util import hex_str_to_bytes, assert_equal
 
 ADDRESS_BCHREG_UNSPENDABLE = 'bchreg:qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqha9s37tt'
 ADDRESS_BCHREG_UNSPENDABLE_DESCRIPTOR = 'addr(bchreg:qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqha9s37tt)#l2wkrsqu'
@@ -28,7 +30,31 @@
         str = str[2:]
     return result
 
-# TODO: def base58_decode
+
+def base58_to_byte(s, verify_checksum=True):
+    if not s:
+        return b''
+    n = 0
+    for c in s:
+        n *= 58
+        assert c in chars
+        digit = chars.index(c)
+        n += digit
+    h = '{:x}'.format(n)
+    if len(h) % 2:
+        h = '0' + h
+    res = n.to_bytes((n.bit_length() + 7) // 8, 'big')
+    pad = 0
+    for c in s:
+        if c == chars[0]:
+            pad += 1
+        else:
+            break
+    res = b'\x00' * pad + res
+    if verify_checksum:
+        assert_equal(hash256(res[:-4])[:4], res[-4:])
+
+    return res[1:-4], int(res[0])
 
 
 def keyhash_to_p2pkh(hash, main=False):
@@ -67,3 +93,41 @@
     if (isinstance(script, bytes) or isinstance(script, CScript)):
         return script
     assert False
+
+
+class TestFrameworkScript(unittest.TestCase):
+    def test_base58encodedecode(self):
+        def check_base58(data, version):
+            self.assertEqual(
+                base58_to_byte(byte_to_base58(data, version)),
+                (data, version))
+
+        check_base58(
+            b'\x1f\x8e\xa1p*{\xd4\x94\x1b\xca\tA\xb8R\xc4\xbb\xfe\xdb.\x05',
+            111)
+        check_base58(
+            b':\x0b\x05\xf4\xd7\xf6l;\xa7\x00\x9fE50)l\x84\\\xc9\xcf', 111)
+        check_base58(
+            b'A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a',
+            111)
+        check_base58(
+            b'\0A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a',
+            111)
+        check_base58(
+            b'\0\0A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a',
+            111)
+        check_base58(
+            b'\0\0\0A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a',
+            111)
+        check_base58(
+            b'\x1f\x8e\xa1p*{\xd4\x94\x1b\xca\tA\xb8R\xc4\xbb\xfe\xdb.\x05', 0)
+        check_base58(
+            b':\x0b\x05\xf4\xd7\xf6l;\xa7\x00\x9fE50)l\x84\\\xc9\xcf', 0)
+        check_base58(
+            b'A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a', 0)
+        check_base58(
+            b'\0A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a', 0)
+        check_base58(
+            b'\0\0A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a', 0)
+        check_base58(
+            b'\0\0\0A\xc1\xea\xf1\x11\x80%Y\xba\xd6\x1b`\xd6+\x1f\x89|c\x92\x8a', 0)
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -75,6 +75,7 @@
 TEST_EXIT_SKIPPED = 77
 
 TEST_FRAMEWORK_MODULES = [
+    "address",
     "script",
 ]