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merged 2 commits into from
Oct 13, 2025
Merged

api/firmware: add simulator tests for P2WSH multisig #142

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37b632f
api/firmware: add simulator tests for P2WSH multisig
benma Oct 3, 2025
7878eef
api/firmware: de-dep multisig setup code
benma Oct 13, 2025
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260 changes: 258 additions & 2 deletions api/firmware/btc_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ package firmware
import (
"bytes"
"errors"
"slices"
"testing"

"github.com/BitBoxSwiss/bitbox02-api-go/api/firmware/messages"
Expand Down Expand Up @@ -74,6 +75,44 @@ func p2shPkScript(redeemScript []byte) []byte {
return pkScript
}

// P2WSH multisig witnessScript and pubkeyScript from these xpubs, derived at /<0;1>/*.
// The pubkeys will be sorted lexicographically.
func multisigP2WSH(threshold int, xpubs []string, change bool, index uint32) ([]byte, []byte) {
pubkeys := make([]*btcutil.AddressPubKey, len(xpubs))
for i, xpubStr := range xpubs {
changeIndex := uint32(0)
if change {
changeIndex = 1
}
xpub := mustXpub(xpubStr, changeIndex, index)
pubKey, err := xpub.ECPubKey()
if err != nil {
panic(err)
}
addrPubKey, err := btcutil.NewAddressPubKey(pubKey.SerializeCompressed(), &chaincfg.MainNetParams)
if err != nil {
panic(err)
}
pubkeys[i] = addrPubKey
}
slices.SortFunc(pubkeys, func(a, b *btcutil.AddressPubKey) int {
return bytes.Compare(a.ScriptAddress(), b.ScriptAddress())
})
witnessScript, err := txscript.MultiSigScript(pubkeys, threshold)
if err != nil {
panic(err)
}
addr, err := btcutil.NewAddressWitnessScriptHash(chainhash.HashB(witnessScript), &chaincfg.MainNetParams)
if err != nil {
panic(err)
}
pkScript, err := txscript.PayToAddrScript(addr)
if err != nil {
panic(err)
}
return witnessScript, pkScript
}

//nolint:unparam
func mustOutpoint(s string) *wire.OutPoint {
outPoint, err := wire.NewOutPointFromString(s)
Expand Down Expand Up @@ -210,14 +249,27 @@ func TestSimulatorBTCAddress(t *testing.T) {
})
}

func mustXpub(xpubStr string, keypath ...uint32) *hdkeychain.ExtendedKey {
xpub, err := hdkeychain.NewKeyFromString(xpubStr)
if err != nil {
panic(err)
}
for _, childIndex := range keypath {
xpub, err = xpub.Derive(childIndex)
if err != nil {
panic(err)
}
}
return xpub
}

func simulatorPub(t *testing.T, device *Device, keypath ...uint32) *btcec.PublicKey {
t.Helper()

xpubStr, err := device.BTCXPub(messages.BTCCoin_BTC, keypath, messages.BTCPubRequest_XPUB, false)
require.NoError(t, err)

xpub, err := hdkeychain.NewKeyFromString(xpubStr)
require.NoError(t, err)
xpub := mustXpub(xpubStr)
pubKey, err := xpub.ECPubKey()
require.NoError(t, err)
return pubKey
Expand Down Expand Up @@ -937,3 +989,207 @@ func TestSimulatorSignBTCTransactionSendSelfDifferentAccount(t *testing.T) {
)
})
}

// 1-of-3 multisig registration and address display/verification.
func TestSimulatorBTCAddressMultisig(t *testing.T) {
testInitializedSimulators(t, func(t *testing.T, device *Device, stdOut *bytes.Buffer) {
t.Helper()

coin := messages.BTCCoin_BTC
keypathAccount := []uint32{
48 + hardenedKeyStart,
0 + hardenedKeyStart,
0 + hardenedKeyStart,
2 + hardenedKeyStart,
}

receiveKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)

ourXPub, err := device.BTCXPub(coin, keypathAccount, messages.BTCPubRequest_XPUB, false)
require.NoError(t, err)

xpubs := []string{
ourXPub,
"xpub6Esa6esRHkbuXtbdDKqu3uWjQ1GpK39WW2hxbUAN4L3TxrwDyghEwBtUYZ8uK8LZh3tJ3pjWEpxng9tjfo7RT9BaZKV2T3EPvmZ6N1LgSdj",
"xpub6FJ6FAAFUzuWQAKyT98Ngs6UwsoPfPCdmepqX2aLLPT54M85ARsWzPciFd49foStMwhWgfiHP6PnMgPrWLrBJpUHgqw8vZPd5ov8uSfW2vo",
}
ourXPubIndex := uint32(0)
threshold := 1

scriptConfig, err := NewBTCScriptConfigMultisig(uint32(threshold), xpubs, ourXPubIndex)
require.NoError(t, err)

// The multisig account has to be registered if not already.
registered, err := device.BTCIsScriptConfigRegistered(coin, scriptConfig, keypathAccount)
require.NoError(t, err)
require.False(t, registered)

err = device.BTCRegisterScriptConfig(coin, scriptConfig, keypathAccount, "My multisig account")
require.NoError(t, err)

address, err := device.BTCAddress(
coin,
receiveKeypath,
scriptConfig,
true,
)
require.NoError(t, err)
require.Equal(t, "bc1qdhqnu2arm9al7uv687amuesk5det5nxx0k9ed30x2u8zjsfnsfyqzlsrsu", address)
if device.Version().AtLeast(semver.NewSemVer(9, 20, 0)) {
// Before simulator v9.20, address confirmation data was not written to stdout.
require.Contains(t,
stdOut.String(),
`TITLE: Register
BODY: 1-of-3
Bitcoin multisig
CONFIRM SCREEN END
CONFIRM SCREEN START
TITLE: Register
BODY: My multisig account
CONFIRM SCREEN END
CONFIRM SCREEN START
TITLE: Register
BODY: p2wsh
at
m/48'/0'/0'/2'
CONFIRM SCREEN END
CONFIRM SCREEN START
TITLE: Register
BODY: Cosigner 1/3 (this device): Zpub74CYNJGx5QwGYeXket9qEbWbEhMNCL1d1Za3eXpABKXMWNVDhTZmovUkzBa74SCrZruMQLGQ6Zce9HzJUaLoF8QPkRU7CVfSSqNZ7Qy2BB5
CONFIRM SCREEN END
CONFIRM SCREEN START
TITLE: Register
BODY: Cosigner 2/3: Zpub75SBqDwhA5FEf49Epht8JA3YTjbyQdp6eXQ55XDgC7ddhF8bFQQeGS4gPg1YsNsJjoBtRMvk3N4PZtjdQR6QC6fT8TzH2GLNMwxFj3Rnnzx
CONFIRM SCREEN END
CONFIRM SCREEN START
TITLE: Register
BODY: Cosigner 3/3: Zpub75rhyjEXMKYqXKsb4XAbw7dJ1c8YkysDv9Wx15deUB3EnjKSS9avKdnv6jvoE3ydQh174CuXBdVPFREkExqA3mxAFzSPVnVbWzKJGVWvYXJ
CONFIRM SCREEN END
STATUS SCREEN START
TITLE: Multisig account
registered
STATUS SCREEN END
CONFIRM SCREEN START
TITLE: Receive to
BODY: 1-of-3
Bitcoin multisig
CONFIRM SCREEN END
CONFIRM SCREEN START
TITLE: Receive to
BODY: My multisig account
CONFIRM SCREEN END
CONFIRM SCREEN START
TITLE: Receive to
BODY: bc1qdhqnu2arm9al7uv687amuesk5det5nxx0k9ed30x2u8zjsfnsfyqzlsrsu
CONFIRM SCREEN END
`,
)
}
})
}

// 1-of-3 P2WSH multisig spend
func TestSimulatorBTCSignMultisig(t *testing.T) {
testInitializedSimulators(t, func(t *testing.T, device *Device, stdOut *bytes.Buffer) {
t.Helper()
coin := messages.BTCCoin_BTC

keypathAccount := []uint32{
48 + hardenedKeyStart,
0 + hardenedKeyStart,
0 + hardenedKeyStart,
2 + hardenedKeyStart,
}

changeKeypath := append(append([]uint32{}, keypathAccount...), 1, 0)
inputKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)

ourXPub, err := device.BTCXPub(coin, keypathAccount, messages.BTCPubRequest_XPUB, false)
require.NoError(t, err)

xpubs := []string{
ourXPub,
"xpub6Esa6esRHkbuXtbdDKqu3uWjQ1GpK39WW2hxbUAN4L3TxrwDyghEwBtUYZ8uK8LZh3tJ3pjWEpxng9tjfo7RT9BaZKV2T3EPvmZ6N1LgSdj",
"xpub6FJ6FAAFUzuWQAKyT98Ngs6UwsoPfPCdmepqX2aLLPT54M85ARsWzPciFd49foStMwhWgfiHP6PnMgPrWLrBJpUHgqw8vZPd5ov8uSfW2vo",
}
ourXPubIndex := uint32(0)
threshold := 1

_, inputPkScript := multisigP2WSH(threshold, xpubs, false, 0)

scriptConfig, err := NewBTCScriptConfigMultisig(uint32(threshold), xpubs, ourXPubIndex)
require.NoError(t, err)

// The multisig account has to be registered if not already.
registered, err := device.BTCIsScriptConfigRegistered(coin, scriptConfig, keypathAccount)
require.NoError(t, err)
require.False(t, registered)

err = device.BTCRegisterScriptConfig(coin, scriptConfig, keypathAccount, "My multisig account")
require.NoError(t, err)
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@bznein bznein Oct 10, 2025 •
edited
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If I'm not mistaken, most of this is identical to the test before (and I think also the one in the other file?). I think it's worth to extract it to a helper function to avoid duplicating code and make it easier to maintain.

I think the only differences are


		changeKeypath := append(append([]uint32{}, keypathAccount...), 1, 0)
		inputKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)

and

		_, inputPkScript := multisigP2WSH(threshold, xpubs, false, 0)

Which are only used later and could be defined closer to where they are needed.

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@benma benma Oct 13, 2025

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Which one exactly? The one before it tests BTCAddress, not BTCSign. The other one is BTCSignPSBT, and creating the PSBT is similar but still quite different.

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@bznein bznein Oct 13, 2025 •
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It seems to me that lines 1094 to 1129 are identical to lines 996 to 1028, with the exception of the creation of this vars:

		changeKeypath := append(append([]uint32{}, keypathAccount...), 1, 0)

		inputKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)


		_, inputPkScript := multisigP2WSH(threshold, xpubs, false, 0)

And on the other one:

		receiveKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)

Which are not used within those blocks and can be left out.

And the same for the other file, I believe all of this code is shared between all three tests:

		t.Helper()

		coin := messages.BTCCoin_BTC

		keypathAccount := []uint32{
			48 + hardenedKeyStart,
			0 + hardenedKeyStart,
			0 + hardenedKeyStart,
			2 + hardenedKeyStart,
		}


	ourXPub, err := device.BTCXPub(coin, keypathAccount, messages.BTCPubRequest_XPUB, false)
		require.NoError(t, err)

		xpubs := []string{
			ourXPub,
			"xpub6Esa6esRHkbuXtbdDKqu3uWjQ1GpK39WW2hxbUAN4L3TxrwDyghEwBtUYZ8uK8LZh3tJ3pjWEpxng9tjfo7RT9BaZKV2T3EPvmZ6N1LgSdj",
			"xpub6FJ6FAAFUzuWQAKyT98Ngs6UwsoPfPCdmepqX2aLLPT54M85ARsWzPciFd49foStMwhWgfiHP6PnMgPrWLrBJpUHgqw8vZPd5ov8uSfW2vo",
		}
		ourXPubIndex := uint32(0)
		threshold := 1

		scriptConfig, err := NewBTCScriptConfigMultisig(uint32(threshold), xpubs, ourXPubIndex)
		require.NoError(t, err)

And can be extracted

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@benma benma Oct 13, 2025

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Added commit, created by deepseek 🤓


prevTx := &wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{
{
PreviousOutPoint: *mustOutpoint("3131313131313131313131313131313131313131313131313131313131313131:0"),
Sequence: 0xFFFFFFFF,
},
},
TxOut: []*wire.TxOut{
{
Value: 100_000_000,
PkScript: inputPkScript,
},
},
LockTime: 0,
}
convertedPrevTx := NewBTCPrevTxFromBtcd(prevTx)

scriptConfigs := []*messages.BTCScriptConfigWithKeypath{
{
ScriptConfig: scriptConfig,
Keypath: keypathAccount,
},
}
require.True(t, BTCSignNeedsPrevTxs(scriptConfigs))

prevTxHash := prevTx.TxHash()
_, err = device.BTCSign(
coin,
scriptConfigs,
nil,
&BTCTx{
Version: 2,
Inputs: []*BTCTxInput{
{
Input: &messages.BTCSignInputRequest{
PrevOutHash: prevTxHash[:],
PrevOutIndex: 0,
PrevOutValue: uint64(prevTx.TxOut[0].Value),
Sequence: 0xFFFFFFFF,
Keypath: inputKeypath,
ScriptConfigIndex: 0,
},
PrevTx: convertedPrevTx,
},
},
Outputs: []*messages.BTCSignOutputRequest{
{
Ours: true,
Value: 70_000_000,
Keypath: changeKeypath,
},
{
Value: 20_000_000,
Payload: []byte("11111111111111111111111111111111"),
Type: messages.BTCOutputType_P2WSH,
},
},
Locktime: 0,
},
messages.BTCSignInitRequest_DEFAULT,
)
require.NoError(t, err)
})
}
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