test: refactor: introduce `generate_keypair` helper with WIF support

In functional tests it is a quite common scenario to generate fresh
elliptic curve keypairs, which is currently a bit cumbersome as it
involves multiple steps, e.g.:

    privkey = ECKey()
    privkey.generate()
    privkey_wif = bytes_to_wif(privkey.get_bytes())
    pubkey = privkey.get_pubkey().get_bytes()

Simplify this by providing a new `generate_keypair` helper function that
returns the private key either as `ECKey` object or as WIF-string
(depending on the boolean `wif` parameter) and the public key as
byte-string; these formats are what we mostly need (currently we don't
use `ECPubKey` objects from generated keypairs anywhere).

With this, most of the affected code blocks following the pattern above
can be replaced by one-liners, e.g.:

    privkey, pubkey = generate_keypair(wif=True)

Note that after this commit, the only direct uses of `ECKey` remain in
situations where we want to set the private key explicitly, e.g. in
MiniWallet (test/functional/test_framework/wallet.py) or the test for
the signet miner script (test/functional/tool_signet_miner.py).

1 files changed, 5 insertions, 7 deletions

diff --git a/test/functional/wallet_createwallet.py b/test/functional/wallet_createwallet.py
index a4e6f96cce..75b507c387 100755
--- a/test/functional/wallet_createwallet.py
+++ b/test/functional/wallet_createwallet.py
@@ -7,13 +7,13 @@
 
 from test_framework.address import key_to_p2wpkh
 from test_framework.descriptors import descsum_create
-from test_framework.key import ECKey
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
     assert_raises_rpc_error,
 )
-from test_framework.wallet_util import bytes_to_wif, generate_wif_key
+from test_framework.wallet_util import generate_keypair
+
 
 EMPTY_PASSPHRASE_MSG = "Empty string given as passphrase, wallet will not be encrypted."
 LEGACY_WALLET_MSG = "Wallet created successfully. The legacy wallet type is being deprecated and support for creating and opening legacy wallets will be removed in the future."
@@ -50,14 +50,12 @@ class CreateWalletTest(BitcoinTestFramework):
         w1.importpubkey(w0.getaddressinfo(address1)['pubkey'])
 
         self.log.info('Test that private keys cannot be imported')
-        eckey = ECKey()
-        eckey.generate()
-        privkey = bytes_to_wif(eckey.get_bytes())
+        privkey, pubkey = generate_keypair(wif=True)
         assert_raises_rpc_error(-4, 'Cannot import private keys to a wallet with private keys disabled', w1.importprivkey, privkey)
         if self.options.descriptors:
             result = w1.importdescriptors([{'desc': descsum_create('wpkh(' + privkey + ')'), 'timestamp': 'now'}])
         else:
-            result = w1.importmulti([{'scriptPubKey': {'address': key_to_p2wpkh(eckey.get_pubkey().get_bytes())}, 'timestamp': 'now', 'keys': [privkey]}])
+            result = w1.importmulti([{'scriptPubKey': {'address': key_to_p2wpkh(pubkey)}, 'timestamp': 'now', 'keys': [privkey]}])
         assert not result[0]['success']
         assert 'warnings' not in result[0]
         assert_equal(result[0]['error']['code'], -4)
@@ -77,7 +75,7 @@ class CreateWalletTest(BitcoinTestFramework):
         assert_raises_rpc_error(-4, "Error: This wallet has no available keys", w3.getnewaddress)
         assert_raises_rpc_error(-4, "Error: This wallet has no available keys", w3.getrawchangeaddress)
         # Import private key
-        w3.importprivkey(generate_wif_key())
+        w3.importprivkey(generate_keypair(wif=True)[0])
         # Imported private keys are currently ignored by the keypool
         assert_equal(w3.getwalletinfo()['keypoolsize'], 0)
         assert_raises_rpc_error(-4, "Error: This wallet has no available keys", w3.getnewaddress)