Implement native canton driver by PawelBis · Pull Request #225 · cordialsys/crosschain

PawelBis · 2026-03-12T11:27:16Z

No description provided.

conorpp · 2026-03-26T13:02:38Z

chain/canton/address/address.go

+func computeFingerprint(rawPubKey []byte) string {
+	// HashPurpose.PublicKeyFingerprint id=12 encoded as big-endian int32 (4 bytes)
+	var purposeBytes [4]byte
+	binary.BigEndian.PutUint32(purposeBytes[:], 12)


would be nice to see a defined constant for this "12" purpose and any comment or link to what the purpose means, or if there are others.

Fix canton tests and remove hardcoded package id's from canton transfer creation path

conorpp · 2026-04-02T15:21:39Z

chain/canton/address/address_test.go

+	for _, seed := range []byte{0, 1, 127, 255} {
+		key := make([]byte, 32)
+		for i := range key {
+			key[i] = seed
+		}
+		addr, err := builder.GetAddressFromPublicKey(key)
+		require.NoError(t, err)
+		_, fp, err := ParsePartyID(addr)
+		require.NoError(t, err)
+		require.Equal(t, 68, len(fp), "fingerprint must always be 68 chars")
+		expected := map[byte]string{
+			0:   "1220ea618da83b6c6b2c4557ffa17d722045169f52b8f50f3b31fc867e266de7e53d",
+			1:   "1220974cb80e78f2fea077628a02faa4c57d68a65036eea27fb3463088a1c8527a99",
+			127: "122087fab42073577d1d066f0cc217b347aedf5a73ee5feaa75d5e96538dad977b91",
+			255: "122044e19d94c296e8397d61e759ff1692e5dff8efbcd70d7a9b4033d8b4a259ccd0",
+		}
+		require.Equal(t, expected[seed], fp)
+	}


little messy, please refactor into full table-based test.

conorpp · 2026-04-02T15:22:23Z

chain/canton/address/address_test.go

+			name:         "valid - pubkey hex name",
+			addr:         xc.Address("aabbccdd::" + validFP),
+			expectedName: "aabbccdd",
+			expectedFP:   validFP,


expectedFP: "1220" + hex.EncodeToString(make([]byte, 32)), // "1220" + 64 zeros

conorpp · 2026-04-02T15:30:48Z

chain/canton/tx_input/tx_input.go

+	PreparedTransaction  *interactive.PreparedTransaction
+	HashingSchemeVersion interactive.HashingSchemeVersion


PreparedTransaction *interactive.PreparedTransaction `json:"prepared_transaction"` HashingSchemeVersion interactive.HashingSchemeVersion `json:"hashing_scheme_version"`

conorpp · 2026-04-02T15:40:41Z

chain/canton/client/client.go

+	var req interactive.ExecuteSubmissionRequest
+	if err := proto.Unmarshal(payload, &req); err != nil {
+		return fmt.Errorf("failed to unmarshal Canton execute request: %w", err)
+	}
+
+	andWaitReq := &interactive.ExecuteSubmissionAndWaitRequest{
+		PreparedTransaction:  req.PreparedTransaction,
+		PartySignatures:      req.PartySignatures,
+		SubmissionId:         req.SubmissionId,
+		UserId:               req.UserId,
+		HashingSchemeVersion: req.HashingSchemeVersion,
+	}


Why unmarshal to ExecuteSubmissionRequest to then convert to ExecuteSubmissionAndWaitRequest?

Wouldn't it be more simple to serialize to ExecuteSubmissionAndWaitRequest originally?

conorpp · 2026-04-02T15:48:24Z

chain/canton/client/client.go

+func extractTransferOutputs(ex *v2.ExercisedEvent, decimals int32) ([]amuletCreation, bool) {
+	if !isTransferExercise(ex) {
+		return nil, false
+	}
+
+	arg := ex.GetChoiceArgument()
+	if arg == nil {
+		return nil, false
+	}
+	root := arg.GetRecord()
+	if root == nil {
+		return nil, false
+	}
+
+	transferRecord := findRecordField(root, "transfer")
+	if transferRecord == nil {
+		return nil, false
+	}
+
+	var outputs []*v2.Value
+	for _, field := range transferRecord.GetFields() {
+		if field.GetLabel() == "outputs" {
+			if list := field.GetValue().GetList(); list != nil {
+				outputs = list.GetElements()
+			}
+			break
+		}
+	}
+	if len(outputs) == 0 {
+		return nil, false
+	}
+
+	parsed := make([]amuletCreation, 0, len(outputs))
+	for _, output := range outputs {
+		record := output.GetRecord()
+		if record == nil {
+			continue
+		}
+		var receiver string
+		var amount xc.AmountBlockchain
+		var ok bool
+		for _, field := range record.GetFields() {
+			switch field.GetLabel() {
+			case "receiver":
+				receiver = field.GetValue().GetParty()
+			case "amount":
+				amount, ok = extractNumericValue(field.GetValue(), decimals)
+			}
+		}
+		if receiver == "" || !ok {
+			continue
+		}
+		parsed = append(parsed, amuletCreation{owner: receiver, amount: amount})
+	}
+	if len(parsed) == 0 {
+		return nil, false
+	}
+	return parsed, true
+}
+
+func extractNumericValue(value *v2.Value, decimals int32) (xc.AmountBlockchain, bool) {
+	if value == nil {
+		return xc.AmountBlockchain{}, false
+	}
+	numeric := value.GetNumeric()
+	if numeric == "" {
+		return xc.AmountBlockchain{}, false
+	}
+	human, err := xc.NewAmountHumanReadableFromStr(numeric)
+	if err != nil {
+		return xc.AmountBlockchain{}, false
+	}
+	return human.ToBlockchain(decimals), true
+}
+
+func extractTransferFee(ex *v2.ExercisedEvent, decimals int32) (xc.AmountBlockchain, bool) {
+	if !isTransferExercise(ex) {
+		return xc.AmountBlockchain{}, false
+	}
+
+	result := ex.GetExerciseResult()
+	if result == nil {
+		return xc.AmountBlockchain{}, false
+	}
+	record := result.GetRecord()
+	if record == nil {
+		return xc.AmountBlockchain{}, false
+	}
+	record = unwrapTransferResultRecord(record)
+
+	if burned, ok := extractBurnedFee(record, decimals); ok {
+		return burned, true
+	}
+	if summaryFee, ok := extractSummaryFee(record, decimals); ok {
+		return summaryFee, true
+	}
+	return xc.AmountBlockchain{}, false
+}
+
+func isTransferExercise(ex *v2.ExercisedEvent) bool {
+	tid := ex.GetTemplateId()
+	if tid == nil || tid.GetModuleName() != "Splice.AmuletRules" {
+		return false
+	}
+	switch ex.GetChoice() {
+	case "AmuletRules_Transfer", "TransferPreapproval_Send":
+		return true
+	default:
+		return false
+	}
+}
+
+func unwrapTransferResultRecord(record *v2.Record) *v2.Record {
+	if nested := findRecordField(record, "result"); nested != nil {
+		return nested
+	}
+	return record
+}
+
+func extractBurnedFee(record *v2.Record, decimals int32) (xc.AmountBlockchain, bool) {
+	metaRecord := findRecordField(record, "meta")
+	if metaRecord == nil {
+		return xc.AmountBlockchain{}, false
+	}
+	valuesRecord := findRecordField(metaRecord, "values")
+	if valuesRecord == nil {
+		return xc.AmountBlockchain{}, false
+	}
+	burnedText, ok := extractTextMapValue(valuesRecord, "splice.lfdecentralizedtrust.org/burned")
+	if !ok || burnedText == "" {
+		return xc.AmountBlockchain{}, false
+	}
+	return parseHumanAmountToBlockchain(burnedText, decimals)
+}
+
+func extractSummaryFee(record *v2.Record, decimals int32) (xc.AmountBlockchain, bool) {
+	summaryRecord := findRecordField(record, "summary")
+	if summaryRecord == nil {
+		return xc.AmountBlockchain{}, false
+	}
+
+	total := xc.NewAmountBlockchainFromUint64(0)
+	found := false
+
+	if senderChangeFeeValue, ok := findValueField(summaryRecord, "senderChangeFee"); ok {
+		if fee, ok := extractNumericValue(senderChangeFeeValue, decimals); ok {
+			total = total.Add(&fee)
+			found = true
+		}
+	}
+	if outputFeesValue, ok := findValueField(summaryRecord, "outputFees"); ok {
+		if list := outputFeesValue.GetList(); list != nil {
+			for _, elem := range list.GetElements() {
+				fee, ok := extractNumericValue(elem, decimals)
+				if !ok {
+					continue
+				}
+				total = total.Add(&fee)
+				found = true
+			}
+		}
+	}
+
+	if !found {
+		return xc.AmountBlockchain{}, false
+	}
+	return total, true
+}
+
+func findRecordField(record *v2.Record, label string) *v2.Record {
+	value, ok := findValueField(record, label)
+	if !ok {
+		return nil
+	}
+	return value.GetRecord()
+}
+
+func findValueField(record *v2.Record, label string) (*v2.Value, bool) {
+	if record == nil {
+		return nil, false
+	}
+	for _, field := range record.GetFields() {
+		if field.GetLabel() == label {
+			return field.GetValue(), true
+		}
+	}
+	return nil, false
+}
+
+func extractTextMapValue(record *v2.Record, key string) (string, bool) {
+	for _, field := range record.GetFields() {
+		if field.GetLabel() != key {
+			continue
+		}
+		return field.GetValue().GetText(), true
+	}
+	return "", false
+}
+
+func parseHumanAmountToBlockchain(value string, decimals int32) (xc.AmountBlockchain, bool) {
+	human, err := xc.NewAmountHumanReadableFromStr(value)
+	if err != nil {
+		return xc.AmountBlockchain{}, false
+	}
+	return human.ToBlockchain(decimals), true
+}
+
+func parseRecoveryLookupId(value string) (int64, string, bool) {
+	idx := strings.Index(value, "-")
+	if idx <= 0 || idx == len(value)-1 {
+		return 0, "", false
+	}
+	beginExclusive, err := strconv.ParseInt(value[:idx], 10, 64)
+	if err != nil {
+		return 0, "", false
+	}
+	return beginExclusive, value[idx+1:], true
+}


If you refactor the protobuf to be generated locally, then you can refactor all of these helpers to be local methods on the pb types, to support TxInfo method.

E.g.

path/to/proto/record.pb.go path/to/proto/record.go // <-- Add our own helpers in our own files like these

conorpp · 2026-04-02T15:50:39Z

chain/canton/client/client.go

+func (client *Client) FetchBlock(ctx context.Context, args *xclient.BlockArgs) (*txinfo.BlockWithTransactions, error) {
+	return &txinfo.BlockWithTransactions{}, errors.New("not implemented")
+}


Is there any equivalent grouping of transactions on Canton that we could build on? Not a big deal if not.

Perhaps just fetching the latest transaction and reporting a "block" with it? Return not-support/not-implemented error kind if height is specified.

conorpp · 2026-04-02T15:56:04Z

client/account.go

+	CreateAccountCallRequired AccountStateEnum = "CreateAccountCallRequired"
+	Pending                   AccountStateEnum = "Pending"
+	Created                   AccountStateEnum = "Created"


Use these values for consistency with other cordialsys apis:

inactive // CreateAccountCall required registering active

PawelBis force-pushed the canton branch 4 times, most recently from 1508c97 to e48912b Compare March 19, 2026 09:56

PawelBis force-pushed the canton branch 4 times, most recently from a5b4628 to 645b15b Compare March 26, 2026 06:45

PawelBis marked this pull request as ready for review March 26, 2026 11:58

PawelBis changed the title ~~CANTON: Wip~~ Implement native canton driver Mar 26, 2026

PawelBis requested a review from conorpp March 26, 2026 12:00

conorpp reviewed Mar 26, 2026

View reviewed changes

PawelBis force-pushed the canton branch from 8cb3e33 to 811b20a Compare March 26, 2026 19:31

PawelBis added 17 commits April 2, 2026 11:27

CANTON: Wip

8694303

CANTON: Prepare CreateAccount method

ed96efc

CANTON: Refactor create account transacction

85f6f1f

CANTON: Improve logging

56f9a4e

CANTON: Add GetAccountState method

d6f0df1

Add AddressBuilder.AddressRegistrationRequired() method

5c43da5

CANTON: Refactor inputs

397efa2

CANTON: Fix tx-info lookup

e548a61

CANTON: Fix tx-info fee report

7dc763d

CANTON: Refactor create account command

4a118bc

CANTON: Fetch synchronizer id

d6d6f03

CANTON: Remove hardcoded env vars and implement CustomConfig

8bce023

CANTON: Remove hardcoded username, read deduplication window from config

ed36c9f

CANTON: Refactor scan api interactions

fbfa736

CANTON: Test fixes and magic value fix

271876a

Fix canton tests and remove hardcoded package id's from canton transfer creation path

CANTON: Fix scan api regression

1caa2fe

CANTON: Remove CustomConfig.validator_party_id

41a5b3a

PawelBis force-pushed the canton branch from 1790f29 to 41a5b3a Compare April 2, 2026 09:28

CANTON: Add CustomConfig comments

46834f1

conorpp reviewed Apr 2, 2026

View reviewed changes

conorpp and others added 5 commits April 2, 2026 16:26

canton: drop using secrets for urls

f464fbb

canton: generate protobuf types locally

67ac7d2

canton: some cleanup

e5aefb9

Canton: Add upload token standard dars script

09f42ce

CANTON: Token setup scripts + balance implementation

2b3b82a

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Implement native canton driver#225

Implement native canton driver#225
PawelBis wants to merge 23 commits intomainfrom
canton

PawelBis commented Mar 12, 2026

Uh oh!

conorpp Mar 26, 2026

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		PreparedTransaction *interactive.PreparedTransaction
		HashingSchemeVersion interactive.HashingSchemeVersion

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PawelBis commented Mar 12, 2026

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