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).

test/functional/feature_assumevalid.py

@@ -35,7 +35,6 @@
     create_block,
     create_coinbase,
 )
-from test_framework.key import ECKey
 from test_framework.messages import (
     CBlockHeader,
     COutPoint,
@@ -46,9 +45,13 @@
     msg_headers,
 )
 from test_framework.p2p import P2PInterface
-from test_framework.script import (CScript, OP_TRUE)
+from test_framework.script import (
+    CScript,
+    OP_TRUE,
+)
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import assert_equal
+from test_framework.wallet_util import generate_keypair
 
 
 class BaseNode(P2PInterface):
@@ -90,9 +93,7 @@ def run_test(self):
         self.blocks = []
 
         # Get a pubkey for the coinbase TXO
-        coinbase_key = ECKey()
-        coinbase_key.generate()
-        coinbase_pubkey = coinbase_key.get_pubkey().get_bytes()
+        _, coinbase_pubkey = generate_keypair()
 
         # Create the first block with a coinbase output to our key
         height = 1

test/functional/feature_block.py

@@ -14,7 +14,6 @@
     get_legacy_sigopcount_block,
     MAX_BLOCK_SIGOPS,
 )
-from test_framework.key import ECKey
 from test_framework.messages import (
     CBlock,
     COIN,
@@ -55,6 +54,7 @@
     assert_equal,
     assert_greater_than,
 )
+from test_framework.wallet_util import generate_keypair
 from data import invalid_txs
 
 
@@ -98,9 +98,7 @@ def run_test(self):
         self.bootstrap_p2p()  # Add one p2p connection to the node
 
         self.block_heights = {}
-        self.coinbase_key = ECKey()
-        self.coinbase_key.generate()
-        self.coinbase_pubkey = self.coinbase_key.get_pubkey().get_bytes()
+        self.coinbase_key, self.coinbase_pubkey = generate_keypair()
         self.tip = None
         self.blocks = {}
         self.genesis_hash = int(self.nodes[0].getbestblockhash(), 16)

test/functional/feature_nulldummy.py

@@ -35,8 +35,7 @@
     assert_raises_rpc_error,
 )
 from test_framework.wallet import getnewdestination
-from test_framework.key import ECKey
-from test_framework.wallet_util import bytes_to_wif
+from test_framework.wallet_util import generate_keypair
 
 NULLDUMMY_ERROR = "non-mandatory-script-verify-flag (Dummy CHECKMULTISIG argument must be zero)"
 
@@ -71,12 +70,9 @@ def create_transaction(self, *, txid, input_details=None, addr, amount, privkey)
         return tx_from_hex(signedtx["hex"])
 
     def run_test(self):
-        eckey = ECKey()
-        eckey.generate()
-        self.privkey = bytes_to_wif(eckey.get_bytes())
-        self.pubkey = eckey.get_pubkey().get_bytes().hex()
-        cms = self.nodes[0].createmultisig(1, [self.pubkey])
-        wms = self.nodes[0].createmultisig(1, [self.pubkey], 'p2sh-segwit')
+        self.privkey, self.pubkey = generate_keypair(wif=True)
+        cms = self.nodes[0].createmultisig(1, [self.pubkey.hex()])
+        wms = self.nodes[0].createmultisig(1, [self.pubkey.hex()], 'p2sh-segwit')
         self.ms_address = cms["address"]
         ms_unlock_details = {"scriptPubKey": address_to_scriptpubkey(self.ms_address).hex(),
                              "redeemScript": cms["redeemScript"]}

test/functional/feature_taproot.py

@@ -97,6 +97,7 @@
     assert_equal,
     random_bytes,
 )
+from test_framework.wallet_util import generate_keypair
 from test_framework.key import (
     generate_privkey,
     compute_xonly_pubkey,
@@ -1186,11 +1187,8 @@ def predict_sigops_ratio(n, dummy_size):
 
     # Also add a few legacy spends into the mix, so that transactions which combine taproot and pre-taproot spends get tested too.
     for compressed in [False, True]:
-        eckey1 = ECKey()
-        eckey1.set(generate_privkey(), compressed)
-        pubkey1 = eckey1.get_pubkey().get_bytes()
-        eckey2 = ECKey()
-        eckey2.set(generate_privkey(), compressed)
+        eckey1, pubkey1 = generate_keypair(compressed=compressed)
+        eckey2, _ = generate_keypair(compressed=compressed)
         for p2sh in [False, True]:
             for witv0 in [False, True]:
                 for hashtype in VALID_SIGHASHES_ECDSA + [random.randrange(0x04, 0x80), random.randrange(0x84, 0x100)]:

test/functional/mempool_accept.py

@@ -9,7 +9,6 @@
 import math
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.key import ECKey
 from test_framework.messages import (
     MAX_BIP125_RBF_SEQUENCE,
     COIN,
@@ -44,6 +43,7 @@
     assert_raises_rpc_error,
 )
 from test_framework.wallet import MiniWallet
+from test_framework.wallet_util import generate_keypair
 
 
 class MempoolAcceptanceTest(BitcoinTestFramework):
@@ -283,9 +283,7 @@ def run_test(self):
             rawtxs=[tx.serialize().hex()],
         )
         tx = tx_from_hex(raw_tx_reference)
-        key = ECKey()
-        key.generate()
-        pubkey = key.get_pubkey().get_bytes()
+        _, pubkey = generate_keypair()
         tx.vout[0].scriptPubKey = keys_to_multisig_script([pubkey] * 3, k=2)  # Some bare multisig script (2-of-3)
         self.check_mempool_result(
             result_expected=[{'txid': tx.rehash(), 'allowed': False, 'reject-reason': 'bare-multisig'}],

test/functional/mempool_dust.py

@@ -5,7 +5,6 @@
 """Test dust limit mempool policy (`-dustrelayfee` parameter)"""
 from decimal import Decimal
 
-from test_framework.key import ECKey
 from test_framework.messages import (
     COIN,
     CTxOut,
@@ -32,6 +31,7 @@
     get_fee,
 )
 from test_framework.wallet import MiniWallet
+from test_framework.wallet_util import generate_keypair
 
 
 DUST_RELAY_TX_FEE = 3000  # default setting [sat/kvB]
@@ -74,11 +74,8 @@ def run_test(self):
         self.wallet = MiniWallet(self.nodes[0])
 
         # prepare output scripts of each standard type
-        key = ECKey()
-        key.generate(compressed=False)
-        uncompressed_pubkey = key.get_pubkey().get_bytes()
-        key.generate(compressed=True)
-        pubkey = key.get_pubkey().get_bytes()
+        _, uncompressed_pubkey = generate_keypair(compressed=False)
+        _, pubkey = generate_keypair(compressed=True)
 
         output_scripts = (
             (key_to_p2pk_script(uncompressed_pubkey),          "P2PK (uncompressed)"),

test/functional/p2p_segwit.py

@@ -14,7 +14,6 @@
     create_block,
     create_coinbase,
 )
-from test_framework.key import ECKey
 from test_framework.messages import (
     MAX_BIP125_RBF_SEQUENCE,
     CBlockHeader,
@@ -89,6 +88,7 @@
     assert_raises_rpc_error,
 )
 from test_framework.wallet import MiniWallet
+from test_framework.wallet_util import generate_keypair
 
 
 MAX_SIGOP_COST = 80000
@@ -1448,9 +1448,7 @@ def test_uncompressed_pubkey(self):
 
         # Segwit transactions using uncompressed pubkeys are not accepted
         # under default policy, but should still pass consensus.
-        key = ECKey()
-        key.generate(False)
-        pubkey = key.get_pubkey().get_bytes()
+        key, pubkey = generate_keypair(compressed=False)
         assert_equal(len(pubkey), 65)  # This should be an uncompressed pubkey
 
         utxo = self.utxo.pop(0)
@@ -1544,11 +1542,7 @@ def test_uncompressed_pubkey(self):
 
     @subtest
     def test_signature_version_1(self):
-
-        key = ECKey()
-        key.generate()
-        pubkey = key.get_pubkey().get_bytes()
-
+        key, pubkey = generate_keypair()
         witness_script = key_to_p2pk_script(pubkey)
         script_pubkey = script_to_p2wsh_script(witness_script)
 

test/functional/rpc_createmultisig.py

@@ -12,13 +12,13 @@
 from test_framework.blocktools import COINBASE_MATURITY
 from test_framework.authproxy import JSONRPCException
 from test_framework.descriptors import descsum_create, drop_origins
-from test_framework.key import ECPubKey, ECKey
+from test_framework.key import ECPubKey
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_raises_rpc_error,
     assert_equal,
 )
-from test_framework.wallet_util import bytes_to_wif
+from test_framework.wallet_util import generate_keypair
 from test_framework.wallet import (
     MiniWallet,
     getnewdestination,
@@ -38,10 +38,9 @@ def get_keys(self):
         self.priv = []
         node0, node1, node2 = self.nodes
         for _ in range(self.nkeys):
-            k = ECKey()
-            k.generate()
-            self.pub.append(k.get_pubkey().get_bytes().hex())
-            self.priv.append(bytes_to_wif(k.get_bytes(), k.is_compressed))
+            privkey, pubkey = generate_keypair(wif=True)
+            self.pub.append(pubkey.hex())
+            self.priv.append(privkey)
         if self.is_bdb_compiled():
             self.final = node2.getnewaddress()
         else:

test/functional/rpc_psbt.py

@@ -8,7 +8,7 @@
 from itertools import product
 
 from test_framework.descriptors import descsum_create
-from test_framework.key import ECKey, H_POINT
+from test_framework.key import H_POINT
 from test_framework.messages import (
     COutPoint,
     CTransaction,
@@ -43,8 +43,8 @@
     random_bytes,
 )
 from test_framework.wallet_util import (
-    bytes_to_wif,
-    get_generate_key
+    generate_keypair,
+    get_generate_key,
 )
 
 import json
@@ -710,9 +710,7 @@ def test_psbt_input_keys(psbt_input, keys):
 
         self.log.info("Test that we can fund psbts with external inputs specified")
 
-        eckey = ECKey()
-        eckey.generate()
-        privkey = bytes_to_wif(eckey.get_bytes())
+        privkey, _ = generate_keypair(wif=True)
 
         self.nodes[1].createwallet("extfund")
         wallet = self.nodes[1].get_wallet_rpc("extfund")
@@ -825,11 +823,9 @@ def test_psbt_input_keys(psbt_input, keys):
         self.nodes[1].createwallet(wallet_name="scriptwatchonly", disable_private_keys=True)
         watchonly = self.nodes[1].get_wallet_rpc("scriptwatchonly")
 
-        eckey = ECKey()
-        eckey.generate()
-        privkey = bytes_to_wif(eckey.get_bytes())
+        privkey, pubkey = generate_keypair(wif=True)
 
-        desc = descsum_create("wsh(pkh({}))".format(eckey.get_pubkey().get_bytes().hex()))
+        desc = descsum_create("wsh(pkh({}))".format(pubkey.hex()))
         if self.options.descriptors:
             res = watchonly.importdescriptors([{"desc": desc, "timestamp": "now"}])
         else:
@@ -846,11 +842,9 @@ def test_psbt_input_keys(psbt_input, keys):
 
         # Same test but for taproot
         if self.options.descriptors:
-            eckey = ECKey()
-            eckey.generate()
-            privkey = bytes_to_wif(eckey.get_bytes())
+            privkey, pubkey = generate_keypair(wif=True)
 
-            desc = descsum_create("tr({},pk({}))".format(H_POINT, eckey.get_pubkey().get_bytes().hex()))
+            desc = descsum_create("tr({},pk({}))".format(H_POINT, pubkey.hex()))
             res = watchonly.importdescriptors([{"desc": desc, "timestamp": "now"}])
             assert res[0]["success"]
             addr = self.nodes[0].deriveaddresses(desc)[0]

test/functional/rpc_signrawtransactionwithkey.py

@@ -11,7 +11,6 @@
     address_to_scriptpubkey,
     script_to_p2sh,
 )
-from test_framework.key import ECKey
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
@@ -23,16 +22,16 @@
     script_to_p2sh_p2wsh_script,
     script_to_p2wsh_script,
 )
+from test_framework.wallet import (
+    getnewdestination,
+)
 from test_framework.wallet_util import (
-    bytes_to_wif,
+    generate_keypair,
 )
 
 from decimal import (
     Decimal,
 )
-from test_framework.wallet import (
-    getnewdestination,
-)
 
 
 class SignRawTransactionWithKeyTest(BitcoinTestFramework):
@@ -80,11 +79,8 @@ def successful_signing_test(self):
     def witness_script_test(self):
         self.log.info("Test signing transaction to P2SH-P2WSH addresses without wallet")
         # Create a new P2SH-P2WSH 1-of-1 multisig address:
-        eckey = ECKey()
-        eckey.generate()
-        embedded_privkey = bytes_to_wif(eckey.get_bytes())
-        embedded_pubkey = eckey.get_pubkey().get_bytes().hex()
-        p2sh_p2wsh_address = self.nodes[1].createmultisig(1, [embedded_pubkey], "p2sh-segwit")
+        embedded_privkey, embedded_pubkey = generate_keypair(wif=True)
+        p2sh_p2wsh_address = self.nodes[1].createmultisig(1, [embedded_pubkey.hex()], "p2sh-segwit")
         # send transaction to P2SH-P2WSH 1-of-1 multisig address
         self.block_hash = self.generate(self.nodes[0], COINBASE_MATURITY + 1)
         self.blk_idx = 0
@@ -109,10 +105,7 @@ def witness_script_test(self):
 
     def verify_txn_with_witness_script(self, tx_type):
         self.log.info("Test with a {} script as the witnessScript".format(tx_type))
-        eckey = ECKey()
-        eckey.generate()
-        embedded_privkey = bytes_to_wif(eckey.get_bytes())
-        embedded_pubkey = eckey.get_pubkey().get_bytes().hex()
+        embedded_privkey, embedded_pubkey = generate_keypair(wif=True)
         witness_script = {
             'P2PKH': key_to_p2pkh_script(embedded_pubkey).hex(),
             'P2PK': key_to_p2pk_script(embedded_pubkey).hex()

test/functional/test_framework/wallet.py

@@ -20,6 +20,7 @@
     key_to_p2wpkh,
     output_key_to_p2tr,
 )
+from test_framework.blocktools import COINBASE_MATURITY
 from test_framework.descriptors import descsum_create
 from test_framework.key import (
     ECKey,
@@ -53,7 +54,7 @@
     assert_equal,
     assert_greater_than_or_equal,
 )
-from test_framework.blocktools import COINBASE_MATURITY
+from test_framework.wallet_util import generate_keypair
 
 DEFAULT_FEE = Decimal("0.0001")
 
@@ -395,9 +396,7 @@ def getnewdestination(address_type='bech32m'):
        'legacy', 'p2sh-segwit', 'bech32' and 'bech32m'. Can be used when a random
        destination is needed, but no compiled wallet is available (e.g. as
        replacement to the getnewaddress/getaddressinfo RPCs)."""
-    key = ECKey()
-    key.generate()
-    pubkey = key.get_pubkey().get_bytes()
+    key, pubkey = generate_keypair()
     if address_type == 'legacy':
         scriptpubkey = key_to_p2pkh_script(pubkey)
         address = key_to_p2pkh(pubkey)