API extension to support Counterwallet (CounterpartyXCP#1005)

* fix OP_RETURN size estimation

* Remove the forced downgrade to pubkeyhash

Bitcoin 0.13.0 allows bare multisig again

* Add extended_tx_info parameter to create_ methods

If this parameter is present, instead of returning a bare unsigned transaction hex, the API will return a JSON object with details about btc spent.  The output looks like this:

{
  "btc_fee": 28621,
  "tx_hex": "0100000001688469...088ac00000000",
  "btc_in": 7683700,
  "btc_out": 0,
  "btc_change": 7655079
}

counterpartylib/lib/api.py

@@ -70,7 +70,7 @@
                 'multisig_dust_size', 'op_return_value', 'pubkey',
                 'allow_unconfirmed_inputs', 'fee', 'fee_provided',
                 'estimate_fee_per_kb', 'estimate_fee_per_kb_nblocks',
-                'unspent_tx_hash', 'custom_inputs', 'dust_return_pubkey', 'disable_utxo_locks']
+                'unspent_tx_hash', 'custom_inputs', 'dust_return_pubkey', 'disable_utxo_locks', 'extended_tx_info']
 
 API_MAX_LOG_SIZE = 10 * 1024 * 1024 #max log size of 20 MB before rotation (make configurable later)
 API_MAX_LOG_COUNT = 10
@@ -312,7 +312,7 @@ def compose_transaction(db, name, params,
                         allow_unconfirmed_inputs=False,
                         fee=None,
                         fee_provided=0,
-                        unspent_tx_hash=None, custom_inputs=None, dust_return_pubkey=None, disable_utxo_locks=False):
+                        unspent_tx_hash=None, custom_inputs=None, dust_return_pubkey=None, disable_utxo_locks=False, extended_tx_info=False):
     """Create and return a transaction."""
 
     # Get provided pubkeys.
@@ -363,7 +363,8 @@ def compose_transaction(db, name, params,
                                         fee_provided=fee_provided,
                                         unspent_tx_hash=unspent_tx_hash, custom_inputs=custom_inputs,
                                         dust_return_pubkey=dust_return_pubkey,
-                                        disable_utxo_locks=disable_utxo_locks)
+                                        disable_utxo_locks=disable_utxo_locks,
+                                        extended_tx_info=extended_tx_info)
 
 def conditional_decorator(decorator, condition):
     """Checks the condition and if True applies specified decorator."""

counterpartylib/lib/transaction.py

@@ -318,7 +318,7 @@ def construct (db, tx_info, encoding='auto',
                multisig_dust_size=config.DEFAULT_MULTISIG_DUST_SIZE,
                op_return_value=config.DEFAULT_OP_RETURN_VALUE,
                exact_fee=None, fee_provided=0, provided_pubkeys=None, dust_return_pubkey=None,
-               allow_unconfirmed_inputs=False, unspent_tx_hash=None, custom_inputs=None, disable_utxo_locks=False):
+               allow_unconfirmed_inputs=False, unspent_tx_hash=None, custom_inputs=None, disable_utxo_locks=False, extended_tx_info=False):
 
     if estimate_fee_per_kb is None:
         estimate_fee_per_kb = config.ESTIMATE_FEE_PER_KB
@@ -443,7 +443,10 @@ def construct (db, tx_info, encoding='auto',
     if encoding == 'multisig':
         data_output_size = 81       # 71 for the data
     elif encoding == 'opreturn':
-        data_output_size = 90       # 80 for the data
+        # prefix + data + 10 bytes script overhead
+        data_output_size = len(config.PREFIX) + 10
+        if data is not None:
+            data_output_size = data_output_size + len(data)
     else:
         data_output_size = p2pkhsize   # Pay‐to‐PubKeyHash (25 for the data?)
     outputs_size = (p2pkhsize * len(destination_outputs)) + (len(data_array) * data_output_size)
@@ -545,24 +548,6 @@ def construct (db, tx_info, encoding='auto',
     else:
         change_output = None
 
-    # in bitcoin core v0.12.1 a -bytespersigop was added that messes with bare multisig transactions,
-    #  as a safeguard we fall back to pubkeyhash encoding when unsure
-    # when len(inputs) > len(data_outputs) there's more bytes:sigops ratio and we can safely continue
-    if encoding == 'multisig' and inputs and data_output and len(inputs) < len(data_array) * 2 and util.enabled('bytespersigop'):
-        # if auto encoding we can do pubkeyhash encoding instead
-        if desired_encoding == 'auto':
-            return construct(db, tx_info,
-                             encoding='pubkeyhash',
-                             fee_per_kb=fee_per_kb,
-                             regular_dust_size=regular_dust_size,
-                             multisig_dust_size=multisig_dust_size,
-                             op_return_value=op_return_value,
-                             exact_fee=exact_fee, fee_provided=fee_provided, provided_pubkeys=provided_pubkeys,
-                             allow_unconfirmed_inputs=allow_unconfirmed_inputs, unspent_tx_hash=unspent_tx_hash, custom_inputs=custom_inputs)
-        # otherwise raise exception
-        else:
-            raise exceptions.EncodingError("multisig will be rejected by Bitcoin Core >= v0.12.1, you should use `encoding=auto` or `encoding=pubkeyhash`")
-
     # Serialise inputs and outputs.
     unsigned_tx = serialise(encoding, inputs, destination_outputs,
                             data_output, change_output,
@@ -593,6 +578,14 @@ def construct (db, tx_info, encoding='auto',
         parsed_source, parsed_destination, x, y, parsed_data = blocks._get_tx_info(unsigned_tx_hex)
     except exceptions.BTCOnlyError:
         # Skip BTC‐only transactions.
+        if extended_tx_info:
+            return {
+                'btc_in': btc_in,
+                'btc_out': destination_btc_out + data_btc_out,
+                'btc_change': change_quantity,
+                'btc_fee': final_fee,
+                'tx_hex': unsigned_tx_hex,
+            }
         return unsigned_tx_hex
     desired_source = script.make_canonical(desired_source)
 
@@ -607,6 +600,14 @@ def construct (db, tx_info, encoding='auto',
 
         raise exceptions.TransactionError('Constructed transaction does not parse correctly: {} ≠ {}'.format(desired, parsed))
 
+    if extended_tx_info:
+        return {
+            'btc_in': btc_in,
+            'btc_out': destination_btc_out + data_btc_out,
+            'btc_change': change_quantity,
+            'btc_fee': final_fee,
+            'tx_hex': unsigned_tx_hex,
+        }
     return unsigned_tx_hex
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

counterpartylib/test/bytespersigop_test.py

@@ -74,39 +74,6 @@ def test_bytespersigop(server_db):
         assert len(tx.vout) == 2
         assert "OP_RETURN" in repr(tx.vout[0].scriptPubKey)
 
-        # ADDR[0], bytespersigop=True, desc 42 bytes, pubkeyhash encoding
-        #  pubkeyhash because ADDR[0] only has 1 UTXO to spend from
-        txhex = api.compose_transaction(
-            server_db, 'issuance',
-            {'source': ADDR[0],
-             'asset': 'TESTING',
-             'quantity': 100,
-             'transfer_destination': None,
-             'divisible': False,
-             'description': 't' * 42},
-        )
-
-        tx = bitcoinlib.core.CTransaction.deserialize(binascii.unhexlify(txhex))
-
-        assert len(tx.vin) == 1
-        assert len(tx.vout) == 8
-        for i in range(7):
-            assert "OP_CHECKSIG" in repr(tx.vout[i].scriptPubKey)
-
-        # ADDR[0], bytespersigop=True, desc 20 bytes, FORCED multisig encoding
-        #  will error because it's not possible, ADDR[0] only has 1 UTXO
-        with pytest.raises(exceptions.EncodingError):
-            txhex = api.compose_transaction(
-                server_db, 'issuance',
-                {'source': ADDR[0],
-                 'asset': 'TESTING',
-                 'quantity': 100,
-                 'transfer_destination': None,
-                 'divisible': False,
-             'description': 't' * 20},
-                encoding='multisig'
-            )
-
         # ADDR[1], bytespersigop=True, desc 41 bytes, opreturn encoding
         txhex = api.compose_transaction(
             server_db, 'issuance',

counterpartylib/test/estimate_fee_per_kb_test.py

@@ -40,7 +40,7 @@ def _fee_per_kb(nblocks):
         sumvin = sum([int(utxos[(bitcoinlib.core.b2lx(vin.prevout.hash), vin.prevout.n)]['amount'] * 1e8) for vin in pretx.vin])
         sumvout = sum([vout.nValue for vout in pretx.vout])
         unsignedsize = 183
-        signedsize = 315
+        signedsize = 263
 
         fee = int((signedsize / 1000) * (fee_per_kb_used or fee_per_kb))
 

counterpartylib/test/fixtures/scenarios/parseblock_unittest_fixture.json

@@ -87,10 +87,10 @@
         "send": "0100000001c1d8c075936c3495f6d653c50f73d987f75448d97a750249b1eb83bee71b24ae000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788acffffffff03361500000000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e87781e0000000000006951210262415bf04af834423d3dd7ada4dc727aa153863ef89fba5aee7fc6fbf1e58754210254da540fb2663b75e6c3cc61190ad0c2431643bab28ced783cd94079bbe72447210282b886c087eb37dc8182f14ba6cc3e9485ed618b95804d44aecc17c300b585b053ae840dea0b000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788ac00000000"
     },
     {
-        "broadcast": "01000000015001af2c4c3bc2c43b6233261394910d10fb157a082d9b3038c65f2d01e4ff200000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e87ffffffff020000000000000000286a26dfa40be0870f3a17475ed261adede27ff45739c8b10035c8bbf7723074918300469ceac959398fc5f5050000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e8700000000"
+        "broadcast": "01000000015001af2c4c3bc2c43b6233261394910d10fb157a082d9b3038c65f2d01e4ff200000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e87ffffffff020000000000000000286a26dfa40be0870f3a17475ed261adede27ff45739c8b10035c8bbf7723074918300469ceac95939a9c9f5050000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e8700000000"
     },
     {
-        "bet": "01000000015001af2c4c3bc2c43b6233261394910d10fb157a082d9b3038c65f2d01e4ff200000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e87ffffffff03361500000000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e870000000000000000346a32dfa40be0870f3a17475ed257ff5583c6f86f39c8b10035c8bbb139707dc4ed6932b6beac2a4d8846b7feb4bf8002b88efeea07adf5050000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e8700000000"
+        "bet": "01000000015001af2c4c3bc2c43b6233261394910d10fb157a082d9b3038c65f2d01e4ff200000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e87ffffffff03361500000000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e870000000000000000346a32dfa40be0870f3a17475ed257ff5583c6f86f39c8b10035c8bbb139707dc4ed6932b6beac2a4d8846b7feb4bf8002b88efeeaf6aff5050000000017a9144264cfd7eb65f8cbbdba98bd9815d5461fad8d7e8700000000"
     },
     {
         "issuance": "01000000017fe100b9f1144c65ff6479f02def936a3eb3b897113edf57cec763ef0627a1fe000000001976a914b390187ef2854422ac5e4a2eb6ffe92496bef52388acffffffff02781e00000000000069512103f216324526136068cea72482c101b243e5421a5f2b9266c27214377ac7d75f4d2103e232b24c9353769321adbc51f5abc998258971fd27d42e07114d775623e3b4492103c403a9364dcb223cc32df5a4afab6089e941590cecfd5ac823c4fcff46e8f6c553aeb20c6d06000000001976a914b390187ef2854422ac5e4a2eb6ffe92496bef52388ac00000000"
@@ -102,10 +102,10 @@
         "issuance": "01000000017fe100b9f1144c65ff6479f02def936a3eb3b897113edf57cec763ef0627a1fe000000001976a914b390187ef2854422ac5e4a2eb6ffe92496bef52388acffffffff02781e00000000000069512103ef16324526136068cea72482c101b243e5421a5f2b9266c2721437792fd75f822103e232b24c935376932a82bb53f0a9c8dc44fa029853d42e07114d775623e3b4d12103c403a9364dcb223cc32df5a4afab6089e941590cecfd5ac823c4fcff46e8f6c553aeb20c6d06000000001976a914b390187ef2854422ac5e4a2eb6ffe92496bef52388ac00000000"
     },
     {
-        "send": "0100000001c1d8c075936c3495f6d653c50f73d987f75448d97a750249b1eb83bee71b24ae000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788acffffffff020000000000000000386a362a504df746f83442653dd7afa4dc727a030865749e9fba5aeb8fd21a9e68edbc79e78ed45723c1072c38aededa458f95fa2bdfdee082a343ea0b000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788ac00000000"
+        "send": "0100000001c1d8c075936c3495f6d653c50f73d987f75448d97a750249b1eb83bee71b24ae000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788acffffffff020000000000000000386a362a504df746f83442653dd7afa4dc727a030865749e9fba5aeb8fd21a9e68edbc79e78ed45723c1072c38aededa458f95fa2bdfdee0822d46ea0b000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788ac00000000"
     },
     {
-        "send": "0100000001ebe3111881a8733ace02271dcf606b7450c41a48c1cb21fd73f4ba787b353ce4000000001976a9148d6ae8a3b381663118b4e1eff4cfc7d0954dd6ec88acffffffff020000000000000000376a353ab408a679f108a19e35886a15c4c468ca75a06699f864a1ff235d087cbdc6ead3bcadef79a5333700c0c2401e15a313463096b9758fc5f505000000001976a9148d6ae8a3b381663118b4e1eff4cfc7d0954dd6ec88ac00000000"
+        "send": "0100000001ebe3111881a8733ace02271dcf606b7450c41a48c1cb21fd73f4ba787b353ce4000000001976a9148d6ae8a3b381663118b4e1eff4cfc7d0954dd6ec88acffffffff020000000000000000376a353ab408a679f108a19e35886a15c4c468ca75a06699f864a1ff235d087cbdc6ead3bcadef79a5333700c0c2401e15a313463096b97532c8f505000000001976a9148d6ae8a3b381663118b4e1eff4cfc7d0954dd6ec88ac00000000"
     },
     {
         "broadcast": "0100000001e80b32fd1670a1dc1c04ea50d944448fdd0f88b1bb1c127ee538d3b740d918c0000000001976a914c1a6de504b9bc0d0d6987312b2e37564079791b788acffffffff02781e00000000000069512102c6b33a609fc6c6aab6a34871732bf9e4e153dd640ea0fc40f5a57b897d6ef1db2103f1ad16418ba7228251a8e915fe8a380fa8dfcf29da2c89ee7bf0af43d6f276282102610f28a56e187f5cd133d7bfe107b159fa3b5129ba35e91fb915fe9a8efa43b453aeb20c6d06000000001976a914c1a6de504b9bc0d0d6987312b2e37564079791b788ac00000000"
@@ -141,9 +141,9 @@
         "send": "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"
     },
     {
-        "issuance": "0100000001c1d8c075936c3495f6d653c50f73d987f75448d97a750249b1eb83bee71b24ae000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788acffffffff020000000000000000356a332a504df746f83442653dd7b9a4dc727a09ac6c089e9fba5aeb8fd21af0e58754da540fb2663b79b6a2be04777ef0a3306526cea343ea0b000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788ac00000000"
+        "issuance": "0100000001c1d8c075936c3495f6d653c50f73d987f75448d97a750249b1eb83bee71b24ae000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788acffffffff020000000000000000356a332a504df746f83442653dd7b9a4dc727a09ac6c089e9fba5aeb8fd21af0e58754da540fb2663b79b6a2be04777ef0a3306526ce7846ea0b000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788ac00000000"
     },
     {
-        "issuance": "0100000001c1d8c075936c3495f6d653c50f73d987f75448d97a750249b1eb83bee71b24ae000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788acffffffff0200000000000000003f6a3d2a504df746f83442653dd7b8a58f7a5b641375109e9fba5aeb8fd21af0f509c47f29b52b01ff570ef34c933606b8812b7f2fde92e38b584cb8321cd593a343ea0b000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788ac00000000"
+        "issuance": "0100000001c1d8c075936c3495f6d653c50f73d987f75448d97a750249b1eb83bee71b24ae000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788acffffffff0200000000000000003f6a3d2a504df746f83442653dd7b8a58f7a5b641375109e9fba5aeb8fd21af0f509c47f29b52b01ff570ef34c933606b8812b7f2fde92e38b584cb8321cd5937e45ea0b000000001976a9144838d8b3588c4c7ba7c1d06f866e9b3739c6303788ac00000000"
     }
 ]