tx output explorer; fix fake_ms_txn and add psbtV2; add ability to add multiple op_returns to fake_txn

releases/Next-ChangeLog.md

@@ -4,6 +4,7 @@ This lists the new changes that have not yet been published in a normal release.
 
 # Shared Improvements - Both Mk4 and Q
 
+- New Feature: Transaction output explorer
 - Enhancement: Stricter p2sh-p2wpkh validation 
 - Enhancement: mention the need to remove old duress wallets before locking down temporary seed
 - Bugfix: Fix PSBTv2 `PSBT_GLOBAL_TX_MODIFIABLE` parsing

shared/auth.py

@@ -21,7 +21,7 @@ from psbt import psbtObject, FatalPSBTIssue, FraudulentChangeOutput
 from files import CardSlot
 from exceptions import HSMDenied
 from version import MAX_TXN_LEN
-from charcodes import KEY_QR, KEY_NFC, KEY_ENTER, KEY_CANCEL
+from charcodes import KEY_QR, KEY_NFC, KEY_ENTER, KEY_CANCEL, KEY_LEFT, KEY_RIGHT
 
 # Where in SPI flash/PSRAM the two PSBT files are (in and out)
 TXN_INPUT_OFFSET = 0
@@ -728,17 +728,27 @@ class ApproveTransaction(UserAuthorizedAction):
                 self.result = await self.save_visualization(msg, (self.stxn_flags & STXN_SIGNED))
                 del self.psbt
                 self.done()
-
                 return
 
             ux_clear_keys(True)
             dis.progress_bar_show(1)  # finish the Validating...
             if not hsm_active:
-                msg.write("Press OK to approve and sign transaction.")
+                explore = self.psbt.num_outputs > 10
+                msg.write("\nPress OK to approve and sign transaction.")
+                if explore:
+                    msg.write(" Press (2) to explore txn.")
                 if self.is_sd and CardSlot.both_inserted():
                     msg.write(" (B) to write to lower SD slot.")
                 msg.write(" X to abort.")
-                ch = await ux_show_story(msg, title="OK TO SEND?", escape="b")
+                while True:
+                    ch = await ux_show_story(msg, title="OK TO SEND?", escape="2b")
+                    if ch == "2" and explore:
+                        await self.txn_explorer()
+                        continue
+                    else:
+                        msg.close()
+                        del msg
+                        break
             else:
                 ch = await hsm_active.approve_transaction(self.psbt, self.psbt_sha, msg.getvalue())
                 dis.progress_bar_show(1)     # finish the Validating...
@@ -832,6 +842,51 @@ class ApproveTransaction(UserAuthorizedAction):
                     continue
                 break
 
+    async def txn_explorer(self):
+        from glob import dis
+        start = 0
+        n = 10
+
+        def make_msg(start, n):
+            dis.fullscreen('Wait...')
+            rv = ""
+            end = min(start + n, self.psbt.num_outputs)
+
+            for idx, out in self.psbt.output_iter(start, end):
+                outp = self.psbt.outputs[idx]
+                item = "Output %d%s:\n\n" % (idx, " (change)" if outp.is_change else "")
+                item += self.render_output(out)
+                item += "\n"
+                rv += item
+
+            if self.psbt.num_outputs > n:
+                rv += "Press RIGHT to see next group, LEFT to go back. X to quit."
+            return rv
+
+        msg = make_msg(start, n)
+        while True:
+            ch = await ux_show_story(msg, escape='79'+KEY_RIGHT+KEY_LEFT)
+            if ch == 'x':
+                del msg
+                return
+            elif (ch in KEY_LEFT+"7"):
+                # go backwards in explorer
+                if (start - n) < 0:
+                    continue
+                else:
+                    start -= n
+            elif (ch in KEY_RIGHT+"9"):
+                # go forwards
+                if (start + n) >= self.psbt.num_outputs:
+                    continue
+                else:
+                    start += n
+            else:
+                # nothing changed - do not recalc msg
+                continue
+
+            msg = make_msg(start, n)
+
     async def save_visualization(self, msg, sign_text=False):
         # write text into spi flash, maybe signing it as we go
         # - return length and checksum

shared/psbt.py

@@ -1050,11 +1050,14 @@ class psbtObject(psbtProxy):
                 raise FatalPSBTIssue("Duplicate key. Key for unknown value already provided in global namespace.")
             self.unknown[key] = val
 
-    def output_iter(self):
+    def output_iter(self, start=0, stop=None):
         # yield the txn's outputs: index, (CTxOut object) for each
+        if stop is None:
+            stop = self.num_outputs
+
         total_out = 0
         if self.is_v2:
-            for idx in range(self.num_outputs):
+            for idx in range(start, stop):
                 out = self.outputs[idx]
                 amount = unpack("<q", self.get(out.amount))[0]
                 spk = self.get(out.script)
@@ -1067,8 +1070,11 @@ class psbtObject(psbtProxy):
             fd = self.fd
             fd.seek(self.vout_start)
 
+            if start != 0:
+                _skip_n_objs(fd, start, 'CTxOut')
+
             tx_out = CTxOut()
-            for idx in range(self.num_outputs):
+            for idx in range(start, stop):
 
                 tx_out.deserialize(fd)
 
@@ -1079,11 +1085,12 @@ class psbtObject(psbtProxy):
 
                 fd.seek(cont)
 
-        if self.total_value_out is None:
-            self.total_value_out = total_out
-        else:
-            assert self.total_value_out == total_out, \
-                '%s != %s' % (self.total_value_out, total_out)
+        if start == 0 and stop == self.num_outputs:
+            if self.total_value_out is None:
+                self.total_value_out = total_out
+            else:
+                assert self.total_value_out == total_out, \
+                    '%s != %s' % (self.total_value_out, total_out)
 
     def parse_txn(self):
         # Need to semi-parse in unsigned transaction.

shared/ux.py

@@ -196,11 +196,6 @@ async def ux_show_story(msg, title=None, escape=None, sensitive=False,
             ln = q1_reword(ln)
 
             lines.extend(word_wrap(ln, CH_PER_W))
-
-        # no longer needed & rude to our caller, but let's save the memory
-        msg.close()
-        del msg
-        gc.collect()
     else:
         # simple string being shown
         msg = q1_reword(msg)

testing/conftest.py

@@ -1,6 +1,6 @@
 # (c) Copyright 2020 by Coinkite Inc. This file is covered by license found in COPYING-CC.
 #
-import pytest, time, sys, random, re, ndef, os, glob, hashlib, json, functools, io, pdb
+import pytest, time, sys, random, re, ndef, os, glob, hashlib, json, functools, io, math, pdb
 from subprocess import check_output
 from ckcc.protocol import CCProtocolPacker
 from helpers import B2A, U2SAT, hash160
@@ -2073,6 +2073,84 @@ def goto_address_explorer(goto_home, pick_menu_item, need_keypress,
 
     return doit
 
+@pytest.fixture
+def txout_explorer(cap_story, press_cancel, need_keypress, is_q1):
+    def doit(data, chain="XTN"):
+        time.sleep(.1)
+        title, story = cap_story()
+        assert title == 'OK TO SEND?'
+        assert "Press (2) to explore txn" in story
+        need_keypress("2")
+        time.sleep(.1)
+
+        n = 10
+        for i in range(0, len(data), n):
+            d = data[i:i + n]
+            time.sleep(.1)
+            _, story = cap_story()
+            ss = story.split("\n\n")
+            assert len(ss) == (len(d) * 2) + 1
+            assert "Press RIGHT to see next group, LEFT to go back." in ss[-1]
+
+            for i, (sa, sb, (af, amount, change)) in enumerate(zip(ss[:-1:2], ss[1::2], d), start=i):
+                if change:
+                    assert f"Output {i} (change):" == sa
+                else:
+                    assert f"Output {i}:" == sa
+
+                txt_amount, _, addr = sb.split("\n")
+                assert txt_amount == f'{amount / 100000000:.8f} {chain}'
+                if af == "p2pkh":
+                    if chain == "BTC":
+                        assert addr.startswith("1")
+                    else:
+                        assert addr[0] in "mn"
+                elif af in ("p2wpkh", "p2wsh"):
+                    target = "bc1q" if chain == "BTC" else "tb1q"
+                    assert addr.startswith(target)
+                elif af in ("p2sh", "p2wpkh-p2sh", "p2wsh-p2sh"):
+                    target = "3" if chain == "BTC" else "2"
+                    assert addr.startswith(target)
+                else:
+                    raise ValueError(f"'{af}' not implemented")
+
+            need_keypress(KEY_RIGHT if is_q1 else "9")
+
+        # 10 outputs per story
+        # currently sitting at the last story in explorer
+        # try to go further (must not work and story is unchanged)
+        for _ in range(2):
+            need_keypress(KEY_RIGHT if is_q1 else "9")
+            time.sleep(.1)
+            _, xstory = cap_story()
+            assert story == xstory
+
+        # go back to first explorer story
+        story_nums = math.ceil(len(data) / 10)
+        for _ in range(story_nums):
+            need_keypress(KEY_LEFT if is_q1 else "7")
+            time.sleep(.1)
+
+        _, story = cap_story()
+        assert "Output 0" in story.split("\n\n")[0]
+
+        # currently sitting at the first story in explorer
+        # try to go further (must not work and story is unchanged)
+        for _ in range(2):
+            need_keypress(KEY_LEFT if is_q1 else "7")
+            time.sleep(.1)
+            _, xstory = cap_story()
+            assert story == xstory
+
+        # leave explorer - will return back to sign story
+        press_cancel()
+        time.sleep(.1)
+        title, _ = cap_story()
+        assert title == 'OK TO SEND?'
+        press_cancel()
+
+    return doit
+
 
 # useful fixtures
 from test_backup import backup_system

testing/test_bbqr.py

@@ -253,16 +253,25 @@ def test_bbqr_psbt(size, encoding, max_ver, partial, segwit, scan_a_qr, readback
     if file_type == 'T':
         assert not partial
         decoded = decode_with_bitcoind(rb)
-    elif file_type == 'P':
+        ic, oc = len(decoded['vin']), len(decoded['vout'])
+    else:
+        assert file_type == 'P'
         assert partial
         assert rb[0:4] == b'psbt'
         decoded = decode_psbt_with_bitcoind(rb)
         assert not decoded['unknown']
-        decoded = decoded['tx']
+        if 'tx' in decoded:
+            # psbt v0
+            decoded = decoded['tx']
+            ic, oc = len(decoded['vin']), len(decoded['vout'])
+        else:
+            # expect psbt v2
+            ic = decoded["input_count"]
+            oc = decoded["output_count"]
 
     # just smoke test; syntax not content
-    assert len(decoded['vin']) == num_in
-    assert len(decoded['vout']) == num_out
+    assert ic == num_in
+    assert oc == num_out
 
     press_cancel()      # back to menu
 

testing/test_hsm.py

@@ -1518,7 +1518,7 @@ def test_priv_over_ux(quick_start_hsm, hsm_status, load_hsm_users):
 @pytest.mark.parametrize("allow_op_return", [False, True])
 def test_op_return_output_local(op_return_data, start_hsm, attempt_psbt, fake_txn, allow_op_return):
     dests = []
-    psbt = fake_txn(2, 2, op_return=(0, op_return_data), capture_scripts=dests)
+    psbt = fake_txn(2, 2, op_return=[(0, op_return_data)], capture_scripts=dests)
     if allow_op_return:
         policy = DICT(rules=[dict(whitelist=[render_address(d) for d in dests[0:2]],
             whitelist_opts=dict(allow_zeroval_outs=True))])

testing/test_multisig.py

@@ -1201,16 +1201,29 @@ def make_myself_wallet(dev, set_bip39_pw, offer_ms_import, press_select, clear_m
     reset_seed_words()
 
 
-@pytest.fixture()
-def fake_ms_txn():
+@pytest.fixture
+def fake_ms_txn(pytestconfig):
     # make various size MULTISIG txn's ... completely fake and pointless values
     # - but has UTXO's to match needs
     from struct import pack
 
-    def doit(num_ins, num_outs, M, keys, fee=10000,
-                outvals=None, segwit_in=False, outstyles=['p2pkh'], change_outputs=[],
-                incl_xpubs=False, hack_change_out=False, hack_psbt=None):
+    def doit(num_ins, num_outs, M, keys, fee=10000, outvals=None, segwit_in=False,
+             outstyles=['p2pkh'], change_outputs=[], incl_xpubs=False, hack_psbt=None,
+             hack_change_out=False, input_amount=1E8, psbt_v2=None):
+
         psbt = BasicPSBT()
+        if psbt_v2 is None:
+            # anything passed directly to this function overrides
+            # pytest flag --psbt2 - only care about pytest flag
+            # if psbt_v2 is not specified (None)
+            psbt_v2 = pytestconfig.getoption('psbt2')
+
+        if psbt_v2:
+            psbt.version = 2
+            psbt.txn_version = 2
+            psbt.input_count = num_ins
+            psbt.output_count = num_outs
+
         txn = CTransaction()
         txn.nVersion = 2
 
@@ -1252,7 +1265,7 @@ def fake_ms_txn():
             )
             supply.vin = [CTxIn(out_point, nSequence=0xffffffff)]
 
-            supply.vout.append(CTxOut(int(1E8), scriptPubKey))
+            supply.vout.append(CTxOut(int(input_amount), scriptPubKey))
 
             if not segwit_in:
                 psbt.inputs[i].utxo = supply.serialize_with_witness()
@@ -1260,13 +1273,21 @@ def fake_ms_txn():
                 psbt.inputs[i].witness_utxo = supply.vout[-1].serialize()
 
             supply.calc_sha256()
+            if psbt_v2:
+                psbt.inputs[i].previous_txid = supply.hash
+                psbt.inputs[i].prevout_idx = 0
+                # TODO sequence
+                # TODO height timelock
+                # TODO time timelock
+
             spendable = CTxIn(COutPoint(supply.sha256, 0), nSequence=0xffffffff)
             txn.vin.append(spendable)
 
         for i in range(num_outs):
-            # random P2PKH
             if not outstyles:
                 style = ADDR_STYLES[i % len(ADDR_STYLES)]
+            elif len(outstyles) == num_outs:
+                style = outstyles[i]
             else:
                 style = outstyles[i % len(outstyles)]
 
@@ -1293,8 +1314,16 @@ def fake_ms_txn():
 
             assert scriptPubKey
 
+            if psbt_v2:
+                psbt.outputs[i].script = scriptPubKey
+                if outvals:
+                    psbt.outputs[i].amount = outvals[i]
+                else:
+                    psbt.outputs[i].amount = int(round(((input_amount * num_ins) - fee) / num_outs, 4))
+
+
             if not outvals:
-                h = CTxOut(int(round(((1E8*num_ins)-fee) / num_outs, 4)), scriptPubKey)
+                h = CTxOut(int(round(((input_amount*num_ins)-fee) / num_outs, 4)), scriptPubKey)
             else:
                 h = CTxOut(int(outvals[i]), scriptPubKey)
 
@@ -2933,4 +2962,36 @@ def test_bare_cc_ms_qr_import(N, make_multisig, scan_a_qr, clear_ms, goto_home,
     assert f"{N}-of-{N}" in story
     press_cancel()
 
+
+@pytest.mark.parametrize("psbtv2", [True, False])
+@pytest.mark.parametrize("data", [
+    # (out_style, amount, is_change)
+    [("p2wsh", 1000000, 0)] * 99,
+    [("p2sh", 1000000, 1)] * 11,
+    [("p2wsh-p2sh", 1000000, 1)] * 18 + [("p2wsh", 50000000, 0)] * 12,
+    [("p2sh", 1000000, 1), ("p2wsh-p2sh", 50000000, 0), ("p2wsh", 800000, 1)] * 14,
+])
+def test_txout_explorer(psbtv2, data, clear_ms, import_ms_wallet, fake_ms_txn,
+                        start_sign, txout_explorer):
+    clear_ms()
+    M, N = 2, 3
+    keys = import_ms_wallet(2, 3, name='ms-test', accept=1)
+
+    outstyles = []
+    outvals = []
+    change_outputs = []
+    for i in range(len(data)):
+        os, ov, is_change = data[i]
+        outstyles.append(os)
+        outvals.append(ov)
+        if is_change:
+            change_outputs.append(i)
+
+    inp_amount = sum(outvals) + 100000  # 100k sat fee
+    psbt = fake_ms_txn(1, len(data), M, keys, outstyles=outstyles,
+                       outvals=outvals, change_outputs=change_outputs,
+                       input_amount=inp_amount, psbt_v2=psbtv2)
+    start_sign(psbt)
+    txout_explorer(data)
+
 # EOF

testing/test_sign.py

@@ -3,7 +3,7 @@
 # Transaction Signing. Important.
 #
 
-import time, pytest, os, random, pdb, struct, base64, binascii, itertools, datetime
+import time, pytest, os, random, pdb, struct, base64, binascii, itertools, datetime, math
 from ckcc_protocol.protocol import CCProtocolPacker, CCProtoError, MAX_TXN_LEN, CCUserRefused
 from binascii import b2a_hex, a2b_hex
 from psbt import BasicPSBT, BasicPSBTInput, BasicPSBTOutput, PSBT_IN_REDEEM_SCRIPT
@@ -20,7 +20,7 @@ from constants import ADDR_STYLES, ADDR_STYLES_SINGLE, SIGHASH_MAP
 from txn import *
 from ctransaction import CTransaction, CTxOut, CTxIn, COutPoint
 from ckcc_protocol.constants import STXN_FINALIZE, STXN_VISUALIZE, STXN_SIGNED
-from charcodes import KEY_QR
+from charcodes import KEY_QR, KEY_RIGHT
 
 
 SEQUENCE_LOCKTIME_TYPE_FLAG = (1 << 22)
@@ -2089,7 +2089,9 @@ def test_no_outputs_tx(fake_txn, microsd_path, goto_home, press_select, pick_men
 
     pick_menu_item('Ready To Sign')
     time.sleep(0.1)
-    pick_menu_item(fname)
+    try:
+        pick_menu_item(fname)
+    except KeyError: pass
     time.sleep(0.1)
     title, story = cap_story()
 
@@ -2820,10 +2822,10 @@ def test_timelocks_visualize(start_sign, end_sign, dev, bitcoind, use_regtest,
 @pytest.mark.parametrize('in_out', [(4,1),(2,2),(2,1)])
 @pytest.mark.parametrize('partial', [False, True])
 @pytest.mark.parametrize('segwit', [True, False])
-def test_bas64_psbt_qr(in_out, partial, segwit, scan_a_qr, readback_bbqr,
-                       goto_home, use_regtest, cap_story, fake_txn, dev,
-                       decode_psbt_with_bitcoind, decode_with_bitcoind,
-                       press_cancel, press_select, need_keypress):
+def test_base64_psbt_qr(in_out, partial, segwit, scan_a_qr, readback_bbqr,
+                        goto_home, use_regtest, cap_story, fake_txn, dev,
+                        decode_psbt_with_bitcoind, decode_with_bitcoind,
+                        press_cancel, press_select, need_keypress):
     def hack(psbt):
         if partial:
             # change first input to not be ours
@@ -2867,16 +2869,25 @@ def test_bas64_psbt_qr(in_out, partial, segwit, scan_a_qr, readback_bbqr,
     if file_type == 'T':
         assert not partial
         decoded = decode_with_bitcoind(rb)
-    elif file_type == 'P':
+        ic, oc = len(decoded['vin']), len(decoded['vout'])
+    else:
+        assert file_type == 'P'
         assert partial
         assert rb[0:4] == b'psbt'
         decoded = decode_psbt_with_bitcoind(rb)
         assert not decoded['unknown']
-        decoded = decoded['tx']
+        if 'tx' in decoded:
+            # psbt v0
+            decoded = decoded['tx']
+            ic, oc = len(decoded['vin']), len(decoded['vout'])
+        else:
+            # expect psbt v2
+            ic = decoded["input_count"]
+            oc = decoded["output_count"]
 
     # just smoke test; syntax not content
-    assert len(decoded['vin']) == num_in
-    assert len(decoded['vout']) == num_out
+    assert ic == num_in
+    assert oc == num_out
 
     press_cancel()      # back to menu
 
@@ -2912,4 +2923,72 @@ def test_sorting_outputs_by_size(fake_txn, start_sign, cap_story, use_testnet,
     assert rest_story in story
     press_cancel()
 
+
+@pytest.mark.parametrize("psbtv2", [True, False])
+@pytest.mark.parametrize("chain", ["BTC", "XTN"])
+@pytest.mark.parametrize("data", [
+    # (out_style, amount, is_change)
+    [("p2pkh", 1000000, 0)] * 99,
+    [("p2wpkh", 1000000, 1)] * 11,
+    [("p2pkh", 1000000, 1)] * 11 + [("p2wpkh", 50000000, 0)] * 16,
+    [("p2pkh", 1000000, 1), ("p2wpkh", 50000000, 0), ("p2wpkh-p2sh", 800000, 1)] * 11,
+])
+def test_txout_explorer(psbtv2, chain, data, fake_txn, start_sign,
+                        settings_set, txout_explorer):
+    settings_set("chain", chain)
+    outstyles = []
+    outvals = []
+    change_outputs = []
+    for i in range(len(data)):
+        os, ov, is_change = data[i]
+        outstyles.append(os)
+        outvals.append(ov)
+        if is_change:
+            change_outputs.append(i)
+
+    inp_amount = sum(outvals) + 100000  # 100k sat fee
+    psbt = fake_txn(1, len(data), segwit_in=True, outstyles=outstyles,
+                    outvals=outvals, change_outputs=change_outputs,
+                    psbt_v2=psbtv2, input_amount=inp_amount)
+
+    start_sign(psbt)
+    txout_explorer(data, chain)
+
+
+def test_txout_explorer_op_return(fake_txn, start_sign, cap_story, is_q1,
+                                  need_keypress, press_cancel):
+    d = [
+        (1, b"Coinkite"),
+        (0, b"Mk1 Mk2 Mk3 Mk4 Q"),
+        (100, b"binarywatch.org"),
+        (100, b"a" * 75),
+    ]
+    psbt = fake_txn(1, 20, segwit_in=False, op_return=d)
+    start_sign(psbt)
+    time.sleep(.1)
+    title, story = cap_story()
+    assert title == 'OK TO SEND?'
+    assert "Press (2) to explore txn" in story
+    need_keypress("2")
+    time.sleep(.1)
+    # OP_RETURN is put at the end of output list (fake_txn)
+    # 20 normal outputs, all OP_RETURN on last page
+    for _ in range(2):
+        need_keypress(KEY_RIGHT if is_q1 else "9")
+
+    time.sleep(.1)
+    _, story = cap_story()
+    ss = story.split("\n\n")
+    for i, (sa, sb, (amount, data)) in enumerate(zip(ss[:-1:2], ss[1::2], d), start=20):
+        assert f"Output {i}:" == sa
+        val, name, dd = sb.split("\n")
+        assert "OP_RETURN" in name
+        assert f'{amount / 100000000:.8f} XTN' == val
+        hex_str, ascii_str = dd.split(" ", 1)
+        assert f"(ascii: {data.decode()})" == ascii_str
+        assert data.hex() == hex_str
+
+    press_cancel()
+    press_cancel()
+
 # EOF

testing/txn.py

@@ -24,7 +24,7 @@ def fake_txn(dev, pytestconfig):
              invals=None, outvals=None, segwit_in=False, wrapped=False,
              outstyles=['p2pkh'],  psbt_hacker=None, change_outputs=[],
              capture_scripts=None, add_xpub=None, op_return=None,
-             psbt_v2=None):
+             psbt_v2=None, input_amount=1E8):
 
         psbt = BasicPSBT()
 
@@ -83,7 +83,7 @@ def fake_txn(dev, pytestconfig):
                 # p2pkh
                 scr = bytes([0x76, 0xa9, 0x14]) + subkey.hash160() + bytes([0x88, 0xac])
 
-            supply.vout.append(CTxOut(int(1E8 if not invals else invals[i]), scr))
+            supply.vout.append(CTxOut(int(input_amount if not invals else invals[i]), scr))
 
             if segwit_in:
                 # just utxo for segwit
@@ -101,13 +101,15 @@ def fake_txn(dev, pytestconfig):
                 # TODO height timelock
                 # TODO time timelock
 
-            spendable = CTxIn(COutPoint(uint256_from_str(supply.hash), 0), nSequence=0xffffffff)
+            spendable = CTxIn(COutPoint(supply.sha256, 0), nSequence=0xffffffff)
             txn.vin.append(spendable)
 
         for i in range(num_outs):
             # random P2PKH
             if not outstyles:
                 style = ADDR_STYLES[i % len(ADDR_STYLES)]
+            elif len(outstyles) == num_outs:
+                style = outstyles[i]
             else:
                 style = outstyles[i % len(outstyles)]
 
@@ -133,10 +135,10 @@ def fake_txn(dev, pytestconfig):
 
             if psbt_v2:
                 psbt.outputs[i].script = act_scr
-                psbt.outputs[i].amount = int(outvals[i] if outvals else round(((1E8*num_ins)-fee) / num_outs, 4))
+                psbt.outputs[i].amount = int(outvals[i] if outvals else round(((input_amount*num_ins)-fee) / num_outs, 4))
 
             if not outvals:
-                h = CTxOut(int(round(((1E8*num_ins)-fee) / num_outs, 4)), act_scr)
+                h = CTxOut(int(round(((input_amount*num_ins)-fee) / num_outs, 4)), act_scr)
             else:
                 h = CTxOut(int(outvals[i]), act_scr)
 
@@ -147,26 +149,27 @@ def fake_txn(dev, pytestconfig):
 
         # op_return is a tuple of (amount, data)
         if op_return:
-            amount, data = op_return
-            op_return_size = len(data)
-            if op_return_size < 76:
-                script = bytes([106, op_return_size]) + data
-            else:
-                script = bytes([106, 76, op_return_size]) + data
+            for op_ret in op_return:
+                amount, data = op_ret
+                op_return_size = len(data)
+                if op_return_size < 76:
+                    script = bytes([106, op_return_size]) + data
+                else:
+                    script = bytes([106, 76, op_return_size]) + data
 
-            op_ret_o = BasicPSBTOutput(idx=len(psbt.outputs))
-            if psbt_v2:
-                op_ret_o.script = script
-                op_ret_o.amount = amount
-                psbt.output_count += 1
-            else:
-                op_return_out = CTxOut(amount, script)
-                txn.vout.append(op_return_out)
+                op_ret_o = BasicPSBTOutput(idx=len(psbt.outputs))
+                if psbt_v2:
+                    op_ret_o.script = script
+                    op_ret_o.amount = amount
+                    psbt.output_count += 1
+                else:
+                    op_return_out = CTxOut(amount, script)
+                    txn.vout.append(op_return_out)
 
-            psbt.outputs.append(op_ret_o)
+                psbt.outputs.append(op_ret_o)
 
-            if capture_scripts is not None:
-                capture_scripts.append(script)
+                if capture_scripts is not None:
+                    capture_scripts.append(script)
 
         if not psbt_v2:
             psbt.txn = txn.serialize_with_witness()