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merged 1 commit into from
May 2, 2025
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firmware/btc: return struct in BTCSign and BTCSignMessage #121

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88 changes: 56 additions & 32 deletions api/firmware/btc.go
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -277,22 +277,29 @@ type BTCTx struct {
PaymentRequests []*messages.BTCPaymentRequestRequest
}

// BTCSignResult is the result of `BTCSign()`.
type BTCSignResult struct {
// Signatures contains the input signatures. One 64 byte signature per input.
Signatures [][]byte
// GeneratedOutputs contains the outputs generated (silent payments). The map key is the input
// index, the map value is the generated pkScript.
GeneratedOutputs map[int][]byte
}

// BTCSign signs a bitcoin or bitcoin-like transaction. The previous transactions of the inputs
// need to be provided if `BTCSignNeedsPrevTxs()` returns true.
//
// Returns one 64 byte signature per input.
func (device *Device) BTCSign(
coin messages.BTCCoin,
scriptConfigs []*messages.BTCScriptConfigWithKeypath,
outputScriptConfigs []*messages.BTCScriptConfigWithKeypath,
tx *BTCTx,
formatUnit messages.BTCSignInitRequest_FormatUnit,
) ([][]byte, map[int][]byte, error) {
) (*BTCSignResult, error) {
generatedOutputs := map[int][]byte{}
if !device.version.AtLeast(semver.NewSemVer(9, 10, 0)) {
for _, sc := range scriptConfigs {
if isTaproot(sc) {
return nil, nil, UnsupportedError("9.10.0")
return nil, UnsupportedError("9.10.0")
}
}
}
Expand All @@ -308,11 +315,11 @@ func (device *Device) BTCSign(
}

if containsSilentPaymentOutputs && !device.version.AtLeast(semver.NewSemVer(9, 21, 0)) {
return nil, nil, UnsupportedError("9.21.0")
return nil, UnsupportedError("9.21.0")
}

if len(outputScriptConfigs) > 0 && !device.version.AtLeast(semver.NewSemVer(9, 22, 0)) {
return nil, nil, UnsupportedError("9.22.0")
return nil, UnsupportedError("9.22.0")
}

signatures := make([][]byte, len(tx.Inputs))
Expand All @@ -330,7 +337,7 @@ func (device *Device) BTCSign(
OutputScriptConfigs: outputScriptConfigs,
}}})
if err != nil {
return nil, nil, err
return nil, err
}

isInputsPass2 := false
Expand All @@ -349,7 +356,7 @@ func (device *Device) BTCSign(
if performAntiklepto {
nonce, err := generateHostNonce()
if err != nil {
return nil, nil, err
return nil, err
}
hostNonce = nonce
input.HostNonceCommitment = &messages.AntiKleptoHostNonceCommitment{
Expand All @@ -361,12 +368,12 @@ func (device *Device) BTCSign(
BtcSignInput: input,
}})
if err != nil {
return nil, nil, err
return nil, err
}

if performAntiklepto {
if next.Type != messages.BTCSignNextResponse_HOST_NONCE || next.AntiKleptoSignerCommitment == nil {
return nil, nil, errp.New("unexpected response; expected signer nonce commitment")
return nil, errp.New("unexpected response; expected signer nonce commitment")
}
signerCommitment := next.AntiKleptoSignerCommitment.Commitment
next, err = device.nestedQueryBtcSign(
Expand All @@ -378,20 +385,20 @@ func (device *Device) BTCSign(
},
})
if err != nil {
return nil, nil, err
return nil, err
}
err := antikleptoVerify(
hostNonce,
signerCommitment,
next.Signature,
)
if err != nil {
return nil, nil, err
return nil, err
}
}
if isInputsPass2 {
if !next.HasSignature {
return nil, nil, errp.New("unexpected response; expected signature")
return nil, errp.New("unexpected response; expected signature")
}
signatures[inputIndex] = next.Signature
}
Expand All @@ -413,7 +420,7 @@ func (device *Device) BTCSign(
},
})
if err != nil {
return nil, nil, err
return nil, err
}
case messages.BTCSignNextResponse_PREVTX_INPUT:
prevtxInput := tx.Inputs[next.Index].PrevTx.Inputs[next.PrevIndex]
Expand All @@ -424,7 +431,7 @@ func (device *Device) BTCSign(
},
})
if err != nil {
return nil, nil, err
return nil, err
}
case messages.BTCSignNextResponse_PREVTX_OUTPUT:
prevtxOutput := tx.Inputs[next.Index].PrevTx.Outputs[next.PrevIndex]
Expand All @@ -435,7 +442,7 @@ func (device *Device) BTCSign(
},
})
if err != nil {
return nil, nil, err
return nil, err
}
case messages.BTCSignNextResponse_OUTPUT:
outputIndex := next.Index
Expand All @@ -444,7 +451,7 @@ func (device *Device) BTCSign(
BtcSignOutput: tx.Outputs[outputIndex],
}})
if err != nil {
return nil, nil, err
return nil, err
}
if next.GeneratedOutputPkscript != nil {
generatedOutputs[int(outputIndex)] = next.GeneratedOutputPkscript
Expand All @@ -455,13 +462,13 @@ func (device *Device) BTCSign(
next.GeneratedOutputPkscript,
)
if err != nil {
return nil, nil, err
return nil, err
}
}
case messages.BTCSignNextResponse_PAYMENT_REQUEST:
paymentRequestIndex := next.Index
if int(paymentRequestIndex) >= len(tx.PaymentRequests) {
return nil, nil, errp.New("payment request index out of bounds")
return nil, errp.New("payment request index out of bounds")
}
paymentRequest := tx.PaymentRequests[paymentRequestIndex]
next, err = device.nestedQueryBtcSign(
Expand All @@ -472,10 +479,13 @@ func (device *Device) BTCSign(
},
)
if err != nil {
return nil, nil, err
return nil, err
}
case messages.BTCSignNextResponse_DONE:
return signatures, generatedOutputs, nil
return &BTCSignResult{
Signatures: signatures,
GeneratedOutputs: generatedOutputs,
}, nil
}
}
}
Expand Down Expand Up @@ -542,18 +552,28 @@ func (device *Device) BTCRegisterScriptConfig(
return nil
}

// BTCSignMessageResult is the result of `BTCSignMessage()`.
type BTCSignMessageResult struct {
// Signature is the 64 byte raw signature.
Signature []byte
// RecID is the recoverable ID.
RecID byte
// ElectrumSig65 is the 65 byte signature in Electrum format.
ElectrumSig65 []byte
}

// BTCSignMessage signs a Bitcoin message. The 64 byte raw signature, the recoverable ID and the 65
// byte signature in Electrum format are returned.
func (device *Device) BTCSignMessage(
coin messages.BTCCoin,
scriptConfig *messages.BTCScriptConfigWithKeypath,
message []byte,
) (raw []byte, recID byte, electrum65 []byte, err error) {
) (*BTCSignMessageResult, error) {
if isTaproot(scriptConfig) {
return nil, 0, nil, errp.New("taproot not supported")
return nil, errp.New("taproot not supported")
}
if !device.version.AtLeast(semver.NewSemVer(9, 2, 0)) {
return nil, 0, nil, UnsupportedError("9.2.0")
return nil, UnsupportedError("9.2.0")
}

supportsAntiklepto := device.version.AtLeast(semver.NewSemVer(9, 5, 0))
Expand All @@ -564,7 +584,7 @@ func (device *Device) BTCSignMessage(
var err error
hostNonce, err = generateHostNonce()
if err != nil {
return nil, 0, nil, err
return nil, err
}
hostNonceCommitment = &messages.AntiKleptoHostNonceCommitment{
Commitment: antikleptoHostCommit(hostNonce),
Expand All @@ -583,14 +603,14 @@ func (device *Device) BTCSignMessage(
}
response, err := device.queryBTC(request)
if err != nil {
return nil, 0, nil, err
return nil, err
}

var signature []byte
if supportsAntiklepto {
signerCommitment, ok := response.Response.(*messages.BTCResponse_AntikleptoSignerCommitment)
if !ok {
return nil, 0, nil, errp.New("unexpected response")
return nil, errp.New("unexpected response")
}
response, err := device.queryBTC(&messages.BTCRequest{
Request: &messages.BTCRequest_AntikleptoSignature{
Expand All @@ -600,12 +620,12 @@ func (device *Device) BTCSignMessage(
},
})
if err != nil {
return nil, 0, nil, err
return nil, err
}

signResponse, ok := response.Response.(*messages.BTCResponse_SignMessage)
if !ok {
return nil, 0, nil, errp.New("unexpected response")
return nil, errp.New("unexpected response")
}
signature = signResponse.SignMessage.Signature
err = antikleptoVerify(
Expand All @@ -614,12 +634,12 @@ func (device *Device) BTCSignMessage(
signature[:64],
)
if err != nil {
return nil, 0, nil, err
return nil, err
}
} else {
signResponse, ok := response.Response.(*messages.BTCResponse_SignMessage)
if !ok {
return nil, 0, nil, errp.New("unexpected response")
return nil, errp.New("unexpected response")
}
signature = signResponse.SignMessage.Signature
}
Expand All @@ -628,5 +648,9 @@ func (device *Device) BTCSignMessage(
// See https://github.com/spesmilo/electrum/blob/84dc181b6e7bb20e88ef6b98fb8925c5f645a765/electrum/ecc.py#L521-L523
const compressed = 4 // BitBox02 uses only compressed pubkeys
electrumSig65 := append([]byte{27 + compressed + recID}, sig...)
return sig, recID, electrumSig65, nil
return &BTCSignMessageResult{
Signature: sig,
RecID: recID,
ElectrumSig65: electrumSig65,
}, nil
}
24 changes: 12 additions & 12 deletions api/firmware/btc_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -161,7 +161,7 @@ func TestSimulatorBTCSignMessage(t *testing.T) {

pubKey := simulatorPub(t, device, keypath...)

sig, _, _, err := device.BTCSignMessage(
result, err := device.BTCSignMessage(
coin,
&messages.BTCScriptConfigWithKeypath{
ScriptConfig: NewBTCScriptConfigSimple(messages.BTCScriptConfig_P2WPKH_P2SH),
Expand All @@ -171,7 +171,7 @@ func TestSimulatorBTCSignMessage(t *testing.T) {
)
require.NoError(t, err)
sigHash := chainhash.DoubleHashB([]byte("\x18Bitcoin Signed Message:\n\x07message"))
require.True(t, parseECDSASignature(t, sig).Verify(sigHash, pubKey))
require.True(t, parseECDSASignature(t, result.Signature).Verify(sigHash, pubKey))
})
}

Expand Down Expand Up @@ -352,7 +352,7 @@ func TestBTCSignMessage(t *testing.T) {
generateHostNonce = func() ([]byte, error) {
return hostNonce, nil
}
sig, recID, electrumSig65, err := env.device.BTCSignMessage(
result, err := env.device.BTCSignMessage(
messages.BTCCoin_BTC,
&messages.BTCScriptConfigWithKeypath{
ScriptConfig: NewBTCScriptConfigSimple(messages.BTCScriptConfig_P2WPKH_P2SH),
Expand All @@ -362,9 +362,9 @@ func TestBTCSignMessage(t *testing.T) {
)
if env.version.AtLeast(semver.NewSemVer(9, 2, 0)) {
require.NoError(t, err)
require.Equal(t, expectedSig[:64], sig)
require.Equal(t, byte(0), recID)
require.Equal(t, electrumSig65, append([]byte{31}, expectedSig[:64]...))
require.Equal(t, expectedSig[:64], result.Signature)
require.Equal(t, byte(0), result.RecID)
require.Equal(t, result.ElectrumSig65, append([]byte{31}, expectedSig[:64]...))
} else {
require.EqualError(t, err, UnsupportedError("9.2.0").Error())
}
Expand Down Expand Up @@ -422,7 +422,7 @@ func TestSimulatorBTCSignTaprootKeySpend(t *testing.T) {
require.False(t, BTCSignNeedsPrevTxs(scriptConfigs))

prevTxHash := prevTx.TxHash()
_, _, err := device.BTCSign(
_, err := device.BTCSign(
coin,
scriptConfigs,
nil,
Expand Down Expand Up @@ -551,7 +551,7 @@ func TestSimulatorBTCSignMixed(t *testing.T) {
require.True(t, BTCSignNeedsPrevTxs(scriptConfigs))

prevTxHash := prevTx.TxHash()
_, _, err := device.BTCSign(
_, err := device.BTCSign(
coin,
scriptConfigs,
nil,
Expand Down Expand Up @@ -648,7 +648,7 @@ func TestSimulatorBTCSignSilentPayment(t *testing.T) {
LockTime: 0,
}
prevTxHash := prevTx.TxHash()
_, generatedOutputs, err := device.BTCSign(
result, err := device.BTCSign(
coin,
[]*messages.BTCScriptConfigWithKeypath{
{
Expand Down Expand Up @@ -707,7 +707,7 @@ func TestSimulatorBTCSignSilentPayment(t *testing.T) {
map[int][]byte{
1: unhex("5120f99b8e8d97aa7b068dd7b4e7ae31f51784f5c2a0cae280748cfd23832b7dcba7"),
},
generatedOutputs,
result.GeneratedOutputs,
)
} else {
require.EqualError(t, err, UnsupportedError("9.21.0").Error())
Expand Down Expand Up @@ -753,7 +753,7 @@ func TestSimulatorSignBTCTransactionSendSelfSameAccount(t *testing.T) {
}

prevTxHash := prevTx.TxHash()
_, _, err := device.BTCSign(
_, err := device.BTCSign(
coin,
scriptConfigs,
nil,
Expand Down Expand Up @@ -847,7 +847,7 @@ func TestSimulatorSignBTCTransactionSendSelfDifferentAccount(t *testing.T) {
outputScriptConfigIndex := uint32(0)

prevTxHash := prevTx.TxHash()
_, _, err := device.BTCSign(
_, err := device.BTCSign(
coin,
scriptConfigs,
outputScriptConfigs,
Expand Down
6 changes: 3 additions & 3 deletions cmd/miniscript/main.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -331,7 +331,7 @@ func main() {
}
accountKeypath := keyOriginInfo.Keypath
mp := multipaths[i]
signatures, _, err := device.BTCSign(
result, err := device.BTCSign(
coin,
[]*messages.BTCScriptConfigWithKeypath{
{
Expand Down Expand Up @@ -390,8 +390,8 @@ func main() {
errpanic(err)

// Convert to DER encoding
signaturesDER := make([][]byte, len(signatures))
for sigIndex, signature := range signatures {
signaturesDER := make([][]byte, len(result.Signatures))
for sigIndex, signature := range result.Signatures {
r := new(btcec.ModNScalar)
r.SetByteSlice(signature[:32])
s := new(btcec.ModNScalar)
Expand Down
2 changes: 1 addition & 1 deletion cmd/paymentrequest/main.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -167,7 +167,7 @@ func main() {
errpanic(err)
paymentRequest.Signature = signature[1:]

_, _, err = device.BTCSign(
_, err = device.BTCSign(
messages.BTCCoin_TBTC,
[]*messages.BTCScriptConfigWithKeypath{
{
Expand Down
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