Feature1

full-stack-asset-transfer-guide/contracts/asset-transfer-go/README.md

@@ -0,0 +1,15 @@
+# Go chaincode for the full-stack asset transfer guide
+
+This folder contains a Go implementation of the `asset-transfer` smart contract used by the full-stack asset transfer guide.
+
+The contract implements the following operations:
+
+- `CreateAsset`
+- `ReadAsset`
+- `UpdateAsset`
+- `DeleteAsset`
+- `AssetExists`
+- `TransferAsset`
+- `GetAllAssets`
+
+The implementation preserves the same asset data model and state-based endorsement behavior as the existing TypeScript contract implementation.

full-stack-asset-transfer-guide/contracts/asset-transfer-go/asset-transfer-chaincode-vars.yml

@@ -0,0 +1,11 @@
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+---
+smart_contract_name: "asset-transfer"
+smart_contract_version: "1.0.0"
+smart_contract_sequence: 1
+smart_contract_package: "asset-transfer.tgz"
+# smart_contract_constructor: "initLedger"
+smart_contract_endorsement_policy: ""
+smart_contract_collections_file: ""

full-stack-asset-transfer-guide/contracts/asset-transfer-go/asset.go

@@ -0,0 +1,14 @@
+package main
+
+type Asset struct {
+	ID             string `json:"ID"`
+	Color          string `json:"Color"`
+	Owner          string `json:"Owner"`
+	AppraisedValue int    `json:"AppraisedValue"`
+	Size           int    `json:"Size"`
+}
+
+type ownerIdentifier struct {
+	Org  string `json:"org"`
+	User string `json:"user"`
+}

full-stack-asset-transfer-guide/contracts/asset-transfer-go/contract.go

@@ -0,0 +1,312 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+
+	"github.com/hyperledger/fabric-chaincode-go/v2/pkg/statebased"
+	"github.com/hyperledger/fabric-contract-api-go/v2/contractapi"
+)
+
+type SmartContract struct {
+	contractapi.Contract
+}
+
+func (s *SmartContract) CreateAsset(ctx contractapi.TransactionContextInterface, asset Asset) error {
+	if asset.ID == "" {
+		return fmt.Errorf("Missing ID")
+	}
+	if asset.Owner == "" {
+		return fmt.Errorf("Missing Owner")
+	}
+
+	exists, err := s.AssetExists(ctx, asset.ID)
+	if err != nil {
+		return err
+	}
+	if exists {
+		return fmt.Errorf("The asset %s already exists", asset.ID)
+	}
+
+	ownerID, err := clientIdentifier(ctx, asset.Owner)
+	if err != nil {
+		return err
+	}
+	asset.Owner, err = toJSON(ownerID)
+	if err != nil {
+		return err
+	}
+
+	assetBytes, err := json.Marshal(asset)
+	if err != nil {
+		return fmt.Errorf("failed to marshal asset: %v", err)
+	}
+
+	if err := ctx.GetStub().PutState(asset.ID, assetBytes); err != nil {
+		return fmt.Errorf("failed to put asset state: %v", err)
+	}
+
+	mspID, err := ctx.GetClientIdentity().GetMSPID()
+	if err != nil {
+		return fmt.Errorf("failed to get client MSPID: %v", err)
+	}
+	if err := setEndorsingOrgs(ctx, asset.ID, mspID); err != nil {
+		return err
+	}
+
+	return ctx.GetStub().SetEvent("CreateAsset", assetBytes)
+}
+
+func (s *SmartContract) ReadAsset(ctx contractapi.TransactionContextInterface, id string) (*Asset, error) {
+	asset, err := s.readAsset(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	return asset, nil
+}
+
+func (s *SmartContract) readAsset(ctx contractapi.TransactionContextInterface, id string) (*Asset, error) {
+	assetBytes, err := ctx.GetStub().GetState(id)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read asset: %v", err)
+	}
+	if len(assetBytes) == 0 {
+		return nil, fmt.Errorf("Sorry, asset %s has not been created", id)
+	}
+
+	var asset Asset
+	if err := json.Unmarshal(assetBytes, &asset); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal asset: %v", err)
+	}
+
+	return &asset, nil
+}
+
+func (s *SmartContract) UpdateAsset(ctx contractapi.TransactionContextInterface, assetUpdate Asset) error {
+	if assetUpdate.ID == "" {
+		return fmt.Errorf("No asset ID specified")
+	}
+
+	existingAsset, err := s.readAsset(ctx, assetUpdate.ID)
+	if err != nil {
+		return err
+	}
+
+	permission, err := hasWritePermission(ctx, existingAsset)
+	if err != nil {
+		return err
+	}
+	if !permission {
+		return fmt.Errorf("Only owner can update assets")
+	}
+
+	updatedAsset := *existingAsset
+	if assetUpdate.Color != "" {
+		updatedAsset.Color = assetUpdate.Color
+	}
+	if assetUpdate.Size != 0 {
+		updatedAsset.Size = assetUpdate.Size
+	}
+	if assetUpdate.AppraisedValue != 0 {
+		updatedAsset.AppraisedValue = assetUpdate.AppraisedValue
+	}
+	updatedAsset.Owner = existingAsset.Owner
+
+	updatedBytes, err := json.Marshal(updatedAsset)
+	if err != nil {
+		return fmt.Errorf("failed to marshal updated asset: %v", err)
+	}
+
+	if err := ctx.GetStub().PutState(updatedAsset.ID, updatedBytes); err != nil {
+		return fmt.Errorf("failed to update asset state: %v", err)
+	}
+
+	mspID, err := ctx.GetClientIdentity().GetMSPID()
+	if err != nil {
+		return fmt.Errorf("failed to get client MSPID: %v", err)
+	}
+	if err := setEndorsingOrgs(ctx, updatedAsset.ID, mspID); err != nil {
+		return err
+	}
+
+	return ctx.GetStub().SetEvent("UpdateAsset", updatedBytes)
+}
+
+func (s *SmartContract) DeleteAsset(ctx contractapi.TransactionContextInterface, id string) error {
+	asset, err := s.readAsset(ctx, id)
+	if err != nil {
+		return err
+	}
+
+	permission, err := hasWritePermission(ctx, asset)
+	if err != nil {
+		return err
+	}
+	if !permission {
+		return fmt.Errorf("Only owner can delete assets")
+	}
+
+	assetBytes, err := json.Marshal(asset)
+	if err != nil {
+		return fmt.Errorf("failed to marshal deleted asset: %v", err)
+	}
+
+	if err := ctx.GetStub().DelState(id); err != nil {
+		return fmt.Errorf("failed to delete asset state: %v", err)
+	}
+
+	if err := ctx.GetStub().SetEvent("DeleteAsset", assetBytes); err != nil {
+		return fmt.Errorf("failed to set delete event: %v", err)
+	}
+
+	return nil
+}
+
+func (s *SmartContract) AssetExists(ctx contractapi.TransactionContextInterface, id string) (bool, error) {
+	assetJSON, err := ctx.GetStub().GetState(id)
+	if err != nil {
+		return false, fmt.Errorf("failed to read asset state: %v", err)
+	}
+
+	return len(assetJSON) > 0, nil
+}
+
+func (s *SmartContract) TransferAsset(ctx contractapi.TransactionContextInterface, id string, newOwner string, newOwnerOrg string) error {
+	asset, err := s.readAsset(ctx, id)
+	if err != nil {
+		return err
+	}
+
+	permission, err := hasWritePermission(ctx, asset)
+	if err != nil {
+		return err
+	}
+	if !permission {
+		return fmt.Errorf("Only owner can transfer assets")
+	}
+
+	ownerID := ownerIdentifier{Org: newOwnerOrg, User: newOwner}
+	asset.Owner, err = toJSON(ownerID)
+	if err != nil {
+		return err
+	}
+
+	assetBytes, err := json.Marshal(asset)
+	if err != nil {
+		return fmt.Errorf("failed to marshal transferred asset: %v", err)
+	}
+
+	if err := ctx.GetStub().PutState(id, assetBytes); err != nil {
+		return fmt.Errorf("failed to update asset state: %v", err)
+	}
+
+	if err := setEndorsingOrgs(ctx, id, newOwnerOrg); err != nil {
+		return err
+	}
+
+	return ctx.GetStub().SetEvent("TransferAsset", assetBytes)
+}
+
+func (s *SmartContract) GetAllAssets(ctx contractapi.TransactionContextInterface) ([]*Asset, error) {
+	iterator, err := ctx.GetStub().GetStateByRange("", "")
+	if err != nil {
+		return nil, fmt.Errorf("failed to get assets by range: %v", err)
+	}
+	defer iterator.Close()
+
+	var assets []*Asset
+	for iterator.HasNext() {
+		queryResponse, err := iterator.Next()
+		if err != nil {
+			return nil, fmt.Errorf("failed to iterate assets: %v", err)
+		}
+
+		var asset Asset
+		if err := json.Unmarshal(queryResponse.Value, &asset); err != nil {
+			continue
+		}
+		assets = append(assets, &asset)
+	}
+
+	return assets, nil
+}
+
+func hasWritePermission(ctx contractapi.TransactionContextInterface, asset *Asset) (bool, error) {
+	clientID, err := clientIdentifier(ctx, "")
+	if err != nil {
+		return false, err
+	}
+
+	var owner ownerIdentifier
+	if err := json.Unmarshal([]byte(asset.Owner), &owner); err != nil {
+		return false, fmt.Errorf("failed to unmarshal owner identifier: %v", err)
+	}
+
+	return clientID.Org == owner.Org, nil
+}
+
+func clientIdentifier(ctx contractapi.TransactionContextInterface, user string) (ownerIdentifier, error) {
+	mspID, err := ctx.GetClientIdentity().GetMSPID()
+	if err != nil {
+		return ownerIdentifier{}, fmt.Errorf("failed to get client MSPID: %v", err)
+	}
+
+	if user == "" {
+		commonName, err := clientCommonName(ctx)
+		if err != nil {
+			return ownerIdentifier{}, err
+		}
+		user = commonName
+	}
+
+	return ownerIdentifier{Org: mspID, User: user}, nil
+}
+
+func clientCommonName(ctx contractapi.TransactionContextInterface) (string, error) {
+	cert, err := ctx.GetClientIdentity().GetX509Certificate()
+	if err != nil {
+		return "", fmt.Errorf("failed to read client certificate: %v", err)
+	}
+
+	if cert.Subject.CommonName != "" {
+		return cert.Subject.CommonName, nil
+	}
+
+	matches := regexp.MustCompile(`^CN=(.*)$`).FindStringSubmatch(cert.Subject.String())
+	if len(matches) != 2 {
+		return "", fmt.Errorf("unable to identify client identity common name: %s", cert.Subject.String())
+	}
+
+	return matches[1], nil
+}
+
+func newOwnerIdentifier(user string, org string) ownerIdentifier {
+	return ownerIdentifier{Org: org, User: user}
+}
+
+func toJSON(o interface{}) (string, error) {
+	bytes, err := json.Marshal(o)
+	if err != nil {
+		return "", fmt.Errorf("failed to marshal owner identifier: %v", err)
+	}
+	return string(bytes), nil
+}
+
+func setEndorsingOrgs(ctx contractapi.TransactionContextInterface, ledgerKey string, orgs ...string) error {
+	policy, err := statebased.NewStateEP(nil)
+	if err != nil {
+		return fmt.Errorf("failed to create state endorsement policy: %v", err)
+	}
+
+	if err := policy.AddOrgs(statebased.RoleTypePeer, orgs...); err != nil {
+		return fmt.Errorf("failed to add orgs to endorsement policy: %v", err)
+	}
+
+	policyBytes, err := policy.Policy()
+	if err != nil {
+		return fmt.Errorf("failed to marshal endorsement policy: %v", err)
+	}
+
+	return ctx.GetStub().SetStateValidationParameter(ledgerKey, policyBytes)
+}

full-stack-asset-transfer-guide/contracts/asset-transfer-go/go.mod

@@ -0,0 +1,28 @@
+module github.com/hyperledger/fabric-samples/full-stack-asset-transfer-guide/contracts/asset-transfer-go
+
+go 1.23.0
+
+require (
+	github.com/hyperledger/fabric-chaincode-go/v2 v2.0.0
+	github.com/hyperledger/fabric-contract-api-go/v2 v2.2.0
+)
+
+require (
+	github.com/go-openapi/jsonpointer v0.21.0 // indirect
+	github.com/go-openapi/jsonreference v0.21.0 // indirect
+	github.com/go-openapi/spec v0.21.0 // indirect
+	github.com/go-openapi/swag v0.23.0 // indirect
+	github.com/hyperledger/fabric-protos-go-apiv2 v0.3.4 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
+	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
+	github.com/xeipuuv/gojsonschema v1.2.0 // indirect
+	golang.org/x/net v0.38.0 // indirect
+	golang.org/x/sys v0.31.0 // indirect
+	golang.org/x/text v0.23.0 // indirect
+	google.golang.org/genproto v0.0.0-20230110181048-76db0878b65f // indirect
+	google.golang.org/grpc v1.71.0 // indirect
+	google.golang.org/protobuf v1.36.4 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)