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firmware/eth: add option to disable antiklepto in ETHSignTypedMessage #163

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Merged
benma merged 1 commit into from
Mar 3, 2026
Merged

firmware/eth: add option to disable antiklepto in ETHSignTypedMessage #163

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4 changes: 4 additions & 0 deletions api/firmware/btc_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -458,6 +458,10 @@ func TestBTCSignMessage(t *testing.T) {
}
}
// Mock host nonce.
prevGenerateHostNonce := generateHostNonce
t.Cleanup(func() {
generateHostNonce = prevGenerateHostNonce
})
generateHostNonce = func() ([]byte, error) {
return hostNonce, nil
}
Expand Down
84 changes: 53 additions & 31 deletions api/firmware/eth.go
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Original file line number Diff line number Diff line change
Expand Up @@ -574,24 +574,37 @@ func getValue(what *messages.ETHTypedMessageValueResponse, msg map[string]interf
}

// ETHSignTypedMessage signs an Ethereum EIP-712 typed message. 27 is added to the recID to denote
// an uncompressed pubkey.
// an uncompressed pubkey. If useAntiklepto is false, signing is deterministic and requires
// firmware >= 9.26.0.
func (device *Device) ETHSignTypedMessage(
chainID uint64,
keypath []uint32,
jsonMsg []byte,
useAntiklepto bool,
) ([]byte, error) {
if !device.version.AtLeast(semver.NewSemVer(9, 12, 0)) {
return nil, UnsupportedError("9.12.0")
}
if !useAntiklepto && !device.version.AtLeast(semver.NewSemVer(9, 26, 0)) {
return nil, UnsupportedError("9.26.0")
}

var msg map[string]interface{}
if err := json.Unmarshal(jsonMsg, &msg); err != nil {
return nil, errp.WithStack(err)
}

hostNonce, err := generateHostNonce()
if err != nil {
return nil, err
var hostNonce []byte
var hostNonceCommitment *messages.AntiKleptoHostNonceCommitment
if useAntiklepto {
var err error
hostNonce, err = generateHostNonce()
if err != nil {
return nil, err
}
hostNonceCommitment = &messages.AntiKleptoHostNonceCommitment{
Commitment: antikleptoHostCommit(hostNonce),
}
}

types := msg["types"].(map[string]interface{})
Expand All @@ -617,13 +630,11 @@ func (device *Device) ETHSignTypedMessage(
request := &messages.ETHRequest{
Request: &messages.ETHRequest_SignTypedMsg{
SignTypedMsg: &messages.ETHSignTypedMessageRequest{
ChainId: chainID,
Keypath: keypath,
Types: parsedTypes,
PrimaryType: msg["primaryType"].(string),
HostNonceCommitment: &messages.AntiKleptoHostNonceCommitment{
Commitment: antikleptoHostCommit(hostNonce),
},
ChainId: chainID,
Keypath: keypath,
Types: parsedTypes,
PrimaryType: msg["primaryType"].(string),
HostNonceCommitment: hostNonceCommitment,
},
},
}
Expand Down Expand Up @@ -651,34 +662,45 @@ func (device *Device) ETHSignTypedMessage(
typedMsgValueResponse, ok = response.Response.(*messages.ETHResponse_TypedMsgValue)
}

signerCommitment, ok := response.Response.(*messages.ETHResponse_AntikleptoSignerCommitment)
if !ok {
return nil, errp.New("unexpected response")
}
response, err = device.queryETH(&messages.ETHRequest{
Request: &messages.ETHRequest_AntikleptoSignature{
AntikleptoSignature: &messages.AntiKleptoSignatureRequest{
HostNonce: hostNonce,
if useAntiklepto {
signerCommitment, ok := response.Response.(*messages.ETHResponse_AntikleptoSignerCommitment)
if !ok {
return nil, errp.New("unexpected response")
}
response, err = device.queryETH(&messages.ETHRequest{
Request: &messages.ETHRequest_AntikleptoSignature{
AntikleptoSignature: &messages.AntiKleptoSignatureRequest{
HostNonce: hostNonce,
},
},
},
})
if err != nil {
return nil, err
})
if err != nil {
return nil, err
}

signResponse, ok := response.Response.(*messages.ETHResponse_Sign)
if !ok {
return nil, errp.New("unexpected response")
}
signature := signResponse.Sign.Signature
err = antikleptoVerify(
hostNonce,
signerCommitment.AntikleptoSignerCommitment.Commitment,
signature[:64],
)
if err != nil {
return nil, err
}
// 27 is the magic constant to add to the recoverable ID to denote an uncompressed pubkey.
signature[64] += 27
return signature, nil
}

signResponse, ok := response.Response.(*messages.ETHResponse_Sign)
if !ok {
return nil, errp.New("unexpected response")
}
signature := signResponse.Sign.Signature
err = antikleptoVerify(
hostNonce,
signerCommitment.AntikleptoSignerCommitment.Commitment,
signature[:64],
)
if err != nil {
return nil, err
}
// 27 is the magic constant to add to the recoverable ID to denote an uncompressed pubkey.
signature[64] += 27
return signature, nil
Expand Down
148 changes: 100 additions & 48 deletions api/firmware/eth_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ import (
"testing"

"github.com/BitBoxSwiss/bitbox02-api-go/api/firmware/messages"
"github.com/BitBoxSwiss/bitbox02-api-go/util/semver"
"github.com/stretchr/testify/require"
"golang.org/x/crypto/sha3"
)
Expand All @@ -18,6 +19,53 @@ func hashKeccak(b []byte) []byte {
return h.Sum(nil)
}

var eip712Msg = []byte(`
{
"types": {
"EIP712Domain": [
{ "name": "name", "type": "string" },
{ "name": "version", "type": "string" },
{ "name": "chainId", "type": "uint256" },
{ "name": "verifyingContract", "type": "address" }
],
"Attachment": [
{ "name": "contents", "type": "string" }
],
"Person": [
{ "name": "name", "type": "string" },
{ "name": "wallet", "type": "address" },
{ "name": "age", "type": "uint8" }
],
"Mail": [
{ "name": "from", "type": "Person" },
{ "name": "to", "type": "Person" },
{ "name": "contents", "type": "string" },
{ "name": "attachments", "type": "Attachment[]" }
]
},
"primaryType": "Mail",
"domain": {
"name": "Ether Mail",
"version": "1",
"chainId": 1,
"verifyingContract": "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"
},
"message": {
"from": {
"name": "Cow",
"wallet": "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826",
"age": 20
},
"to": {
"name": "Bob",
"wallet": "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB",
"age": "0x1e"
},
"contents": "Hello, Bob!",
"attachments": [{ "contents": "attachment1" }, { "contents": "attachment2" }]
}
}`)

func parseTypeNoErr(t *testing.T, typ string, types map[string]interface{}) *messages.ETHSignTypedMessageRequest_MemberType {
t.Helper()
parsed, err := parseType(typ, types)
Expand Down Expand Up @@ -306,53 +354,6 @@ func TestSimulatorETHSignMessage(t *testing.T) {
func TestSimulatorETHSignTypedMessage(t *testing.T) {
testInitializedSimulators(t, func(t *testing.T, device *Device, stdOut *bytes.Buffer) {
t.Helper()
msg := []byte(`
{
"types": {
"EIP712Domain": [
{ "name": "name", "type": "string" },
{ "name": "version", "type": "string" },
{ "name": "chainId", "type": "uint256" },
{ "name": "verifyingContract", "type": "address" }
],
"Attachment": [
{ "name": "contents", "type": "string" }
],
"Person": [
{ "name": "name", "type": "string" },
{ "name": "wallet", "type": "address" },
{ "name": "age", "type": "uint8" }
],
"Mail": [
{ "name": "from", "type": "Person" },
{ "name": "to", "type": "Person" },
{ "name": "contents", "type": "string" },
{ "name": "attachments", "type": "Attachment[]" }
]
},
"primaryType": "Mail",
"domain": {
"name": "Ether Mail",
"version": "1",
"chainId": 1,
"verifyingContract": "0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC"
},
"message": {
"from": {
"name": "Cow",
"wallet": "0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826",
"age": 20
},
"to": {
"name": "Bob",
"wallet": "0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB",
"age": "0x1e"
},
"contents": "Hello, Bob!",
"attachments": [{ "contents": "attachment1" }, { "contents": "attachment2" }]
}
}`)

sig, err := device.ETHSignTypedMessage(
1,
[]uint32{
Expand All @@ -362,13 +363,64 @@ func TestSimulatorETHSignTypedMessage(t *testing.T) {
0,
10,
},
msg,
eip712Msg,
true,
)
require.NoError(t, err)
require.Len(t, sig, 65)
})
}

func TestSimulatorETHSignTypedMessageAntikleptoEnabled(t *testing.T) {
testInitializedSimulators(t, func(t *testing.T, device *Device, stdOut *bytes.Buffer) {
t.Helper()
keypath := []uint32{
44 + hardenedKeyStart,
60 + hardenedKeyStart,
0 + hardenedKeyStart,
0,
10,
}

sig1, err := device.ETHSignTypedMessage(1, keypath, eip712Msg, true)
require.NoError(t, err)
sig2, err := device.ETHSignTypedMessage(1, keypath, eip712Msg, true)
require.NoError(t, err)

require.Len(t, sig1, 65)
require.Len(t, sig2, 65)
require.NotEqual(t, sig1, sig2)
})
}

func TestSimulatorETHSignTypedMessageAntikleptoDisabled(t *testing.T) {
testInitializedSimulators(t, func(t *testing.T, device *Device, stdOut *bytes.Buffer) {
t.Helper()
keypath := []uint32{
44 + hardenedKeyStart,
60 + hardenedKeyStart,
0 + hardenedKeyStart,
0,
10,
}

if device.Version().AtLeast(semver.NewSemVer(9, 26, 0)) {
sig1, err := device.ETHSignTypedMessage(1, keypath, eip712Msg, false)
require.NoError(t, err)
sig2, err := device.ETHSignTypedMessage(1, keypath, eip712Msg, false)
require.NoError(t, err)

require.Len(t, sig1, 65)
require.Len(t, sig2, 65)
require.Equal(t, sig1, sig2)
return
}

_, err := device.ETHSignTypedMessage(1, keypath, eip712Msg, false)
require.EqualError(t, err, UnsupportedError("9.26.0").Error())
})
}

func TestSimulatorETHSign(t *testing.T) {
testInitializedSimulators(t, func(t *testing.T, device *Device, stdOut *bytes.Buffer) {
t.Helper()
Expand Down
1 change: 1 addition & 0 deletions cmd/playground/main.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -267,6 +267,7 @@ func main() {
"attachments": [{ "contents": "attachment1" }, { "contents": "attachment2" }]
}
}`),
true,
)
errpanic(err)
fmt.Println(sig)
Expand Down
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