text: #!/usr/bin/env python3
  # Copyright (c) 2012-2018 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  '''
  Generate valid and invalid base58 address and private key test vectors.
  
  Usage:
      PYTHONPATH=../../test/functional/test_framework ./gen_key_io_test_vectors.py valid 50 > ../../src/test/data/key_io_valid.json
      PYTHONPATH=../../test/functional/test_framework ./gen_key_io_test_vectors.py invalid 50 > ../../src/test/data/key_io_invalid.json
  '''
  # 2012 Wladimir J. van der Laan
  # Released under MIT License
  import os
  from itertools import islice
  from base58 import b58encode_chk, b58decode_chk, b58chars
  import random
  from binascii import b2a_hex
  from segwit_addr import bech32_encode, decode, convertbits, CHARSET
  
  # key types
  PUBKEY_ADDRESS = 48
  SCRIPT_ADDRESS = 5
  SCRIPT_ADDRESS2 = 50
  PUBKEY_ADDRESS_TEST = 111
  SCRIPT_ADDRESS_TEST = 196
  SCRIPT_ADDRESS_TEST2 = 58
  PUBKEY_ADDRESS_REGTEST = 111
  SCRIPT_ADDRESS_REGTEST = 196
  PRIVKEY = 176
  PRIVKEY_TEST = 239
  PRIVKEY_REGTEST = 239
  
  # script
  OP_0 = 0x00
  OP_1 = 0x51
  OP_2 = 0x52
  OP_16 = 0x60
  OP_DUP = 0x76
  OP_EQUAL = 0x87
  OP_EQUALVERIFY = 0x88
  OP_HASH160 = 0xa9
  OP_CHECKSIG = 0xac
  pubkey_prefix = (OP_DUP, OP_HASH160, 20)
  pubkey_suffix = (OP_EQUALVERIFY, OP_CHECKSIG)
  script_prefix = (OP_HASH160, 20)
  script_suffix = (OP_EQUAL,)
  p2wpkh_prefix = (OP_0, 20)
  p2wsh_prefix = (OP_0, 32)
  
  metadata_keys = ['isPrivkey', 'chain', 'isCompressed', 'tryCaseFlip']
  # templates for valid sequences
  templates = [
    # prefix, payload_size, suffix, metadata, output_prefix, output_suffix
    #                                  None = N/A
    ((PUBKEY_ADDRESS,),         20, (),   (False, 'main',    None,  None), pubkey_prefix, pubkey_suffix),
    ((SCRIPT_ADDRESS,),         20, (),   (False, 'main',    None,  None), script_prefix, script_suffix),
    ((SCRIPT_ADDRESS2,),        20, (),   (False, 'main',    None,  None), script_prefix, script_suffix),
    ((PUBKEY_ADDRESS_TEST,),    20, (),   (False, 'test',    None,  None), pubkey_prefix, pubkey_suffix),
    ((SCRIPT_ADDRESS_TEST,),    20, (),   (False, 'test',    None,  None), script_prefix, script_suffix),
    ((SCRIPT_ADDRESS_TEST2,),   20, (),   (False, 'test',    None,  None), script_prefix, script_suffix),
    ((PUBKEY_ADDRESS_REGTEST,), 20, (),   (False, 'regtest', None,  None), pubkey_prefix, pubkey_suffix),
    ((SCRIPT_ADDRESS_REGTEST,), 20, (),   (False, 'regtest', None,  None), script_prefix, script_suffix),
    ((PRIVKEY,),                32, (),   (True,  'main',    False, None), (),            ()),
    ((PRIVKEY,),                32, (1,), (True,  'main',    True,  None), (),            ()),
    ((PRIVKEY_TEST,),           32, (),   (True,  'test',    False, None), (),            ()),
    ((PRIVKEY_TEST,),           32, (1,), (True,  'test',    True,  None), (),            ()),
    ((PRIVKEY_REGTEST,),        32, (),   (True,  'regtest', False, None), (),            ()),
    ((PRIVKEY_REGTEST,),        32, (1,), (True,  'regtest', True,  None), (),            ())
  ]
  # templates for valid bech32 sequences
  bech32_templates = [
    # hrp, version, witprog_size, metadata, output_prefix
    ('grana',   0, 20, (False, 'main',    None, True), p2wpkh_prefix),
    ('grana',   0, 32, (False, 'main',    None, True), p2wsh_prefix),
    ('grana',   1,  2, (False, 'main',    None, True), (OP_1, 2)),
    ('tgrana',  0, 20, (False, 'test',    None, True), p2wpkh_prefix),
    ('tgrana',  0, 32, (False, 'test',    None, True), p2wsh_prefix),
    ('tgrana',  2, 16, (False, 'test',    None, True), (OP_2, 16)),
    ('rgrana',  0, 20, (False, 'regtest', None, True), p2wpkh_prefix),
    ('rgrana',  0, 32, (False, 'regtest', None, True), p2wsh_prefix),
    ('rgrana', 16, 40, (False, 'regtest', None, True), (OP_16, 40))
  ]
  # templates for invalid bech32 sequences
  bech32_ng_templates = [
    # hrp, version, witprog_size, invalid_bech32, invalid_checksum, invalid_char
    ('tc',    0, 20, False, False, False),
    ('tgrana',  17, 32, False, False, False),
    ('rgrana',  3,  1, False, False, False),
    ('grana',   15, 41, False, False, False),
    ('tgrana',  0, 16, False, False, False),
    ('rgrana',  0, 32, True,  False, False),
    ('grana',   0, 16, True,  False, False),
    ('tgrana',  0, 32, False, True,  False),
    ('rgrana',  0, 20, False, False, True)
  ]
  
  def is_valid(v):
      '''Check vector v for validity'''
      if len(set(v) - set(b58chars)) > 0:
          return is_valid_bech32(v)
      result = b58decode_chk(v)
      if result is None:
          return is_valid_bech32(v)
      for template in templates:
          prefix = bytearray(template[0])
          suffix = bytearray(template[2])
          if result.startswith(prefix) and result.endswith(suffix):
              if (len(result) - len(prefix) - len(suffix)) == template[1]:
                  return True
      return is_valid_bech32(v)
  
  def is_valid_bech32(v):
      '''Check vector v for bech32 validity'''
      for hrp in ['grana', 'tgrana', 'rgrana']:
          if decode(hrp, v) != (None, None):
              return True
      return False
  
  def gen_valid_base58_vector(template):
      '''Generate valid base58 vector'''
      prefix = bytearray(template[0])
      payload = bytearray(os.urandom(template[1]))
      suffix = bytearray(template[2])
      dst_prefix = bytearray(template[4])
      dst_suffix = bytearray(template[5])
      rv = b58encode_chk(prefix + payload + suffix)
      return rv, dst_prefix + payload + dst_suffix
  
  def gen_valid_bech32_vector(template):
      '''Generate valid bech32 vector'''
      hrp = template[0]
      witver = template[1]
      witprog = bytearray(os.urandom(template[2]))
      dst_prefix = bytearray(template[4])
      rv = bech32_encode(hrp, [witver] + convertbits(witprog, 8, 5))
      return rv, dst_prefix + witprog
  
  def gen_valid_vectors():
      '''Generate valid test vectors'''
      glist = [gen_valid_base58_vector, gen_valid_bech32_vector]
      tlist = [templates, bech32_templates]
      while True:
          for template, valid_vector_generator in [(t, g) for g, l in zip(glist, tlist) for t in l]:
              rv, payload = valid_vector_generator(template)
              assert is_valid(rv)
              metadata = {x: y for x, y in zip(metadata_keys,template[3]) if y is not None}
              hexrepr = b2a_hex(payload)
              if isinstance(hexrepr, bytes):
                  hexrepr = hexrepr.decode('utf8')
              yield (rv, hexrepr, metadata)
  
  def gen_invalid_base58_vector(template):
      '''Generate possibly invalid vector'''
      # kinds of invalid vectors:
      #   invalid prefix
      #   invalid payload length
      #   invalid (randomized) suffix (add random data)
      #   corrupt checksum
      corrupt_prefix = randbool(0.2)
      randomize_payload_size = randbool(0.2)
      corrupt_suffix = randbool(0.2)
  
      if corrupt_prefix:
          prefix = os.urandom(1)
      else:
          prefix = bytearray(template[0])
  
      if randomize_payload_size:
          payload = os.urandom(max(int(random.expovariate(0.5)), 50))
      else:
          payload = os.urandom(template[1])
  
      if corrupt_suffix:
          suffix = os.urandom(len(template[2]))
      else:
          suffix = bytearray(template[2])
  
      val = b58encode_chk(prefix + payload + suffix)
      if random.randint(0,10)<1: # line corruption
          if randbool(): # add random character to end
              val += random.choice(b58chars)
          else: # replace random character in the middle
              n = random.randint(0, len(val))
              val = val[0:n] + random.choice(b58chars) + val[n+1:]
  
      return val
  
  def gen_invalid_bech32_vector(template):
      '''Generate possibly invalid bech32 vector'''
      no_data = randbool(0.1)
      to_upper = randbool(0.1)
      hrp = template[0]
      witver = template[1]
      witprog = bytearray(os.urandom(template[2]))
  
      if no_data:
          rv = bech32_encode(hrp, [])
      else:
          data = [witver] + convertbits(witprog, 8, 5)
          if template[3] and not no_data:
              if template[2] % 5 in {2, 4}:
                  data[-1] |= 1
              else:
                  data.append(0)
          rv = bech32_encode(hrp, data)
  
      if template[4]:
          i = len(rv) - random.randrange(1, 7)
          rv = rv[:i] + random.choice(CHARSET.replace(rv[i], '')) + rv[i + 1:]
      if template[5]:
          i = len(hrp) + 1 + random.randrange(0, len(rv) - len(hrp) - 4)
          rv = rv[:i] + rv[i:i + 4].upper() + rv[i + 4:]
  
      if to_upper:
          rv = rv.swapcase()
  
      return rv
  
  def randbool(p = 0.5):
      '''Return True with P(p)'''
      return random.random() < p
  
  def gen_invalid_vectors():
      '''Generate invalid test vectors'''
      # start with some manual edge-cases
      yield "",
      yield "x",
      glist = [gen_invalid_base58_vector, gen_invalid_bech32_vector]
      tlist = [templates, bech32_ng_templates]
      while True:
          for template, invalid_vector_generator in [(t, g) for g, l in zip(glist, tlist) for t in l]:
              val = invalid_vector_generator(template)
              if not is_valid(val):
                  yield val,
  
  if __name__ == '__main__':
      import sys
      import json
      iters = {'valid':gen_valid_vectors, 'invalid':gen_invalid_vectors}
      try:
          uiter = iters[sys.argv[1]]
      except IndexError:
          uiter = gen_valid_vectors
      try:
          count = int(sys.argv[2])
      except IndexError:
          count = 0
  
      data = list(islice(uiter(), count))
      json.dump(data, sys.stdout, sort_keys=True, indent=4)
      sys.stdout.write('\n')
  
  