Adding DID Document Builder

did/builder.go

@@ -0,0 +1,158 @@
+package did
+
+import (
+	"reflect"
+
+	"github.com/TBD54566975/ssi-sdk/util"
+	"github.com/google/uuid"
+	"github.com/pkg/errors"
+)
+
+// contexts and types are kept to avoid having cast to/from interface{} values
+type DIDDocumentBuilder struct {
+	contexts []string
+	types    []string
+	*DIDDocument
+}
+
+const (
+	DIDDocumentLDContext string = "https://w3id.org/did/v1"
+	DIDDocumentType      string = "DIDDocument"
+	BuilderEmptyError    string = "builder cannot be empty"
+)
+
+// Create a new DID Document Builder
+func NewDIDDocumentBuilder() DIDDocumentBuilder {
+	contexts := []string{DIDDocumentLDContext}
+	types := []string{DIDDocumentType}
+	return DIDDocumentBuilder{
+		contexts: contexts,
+		types:    types,
+		DIDDocument: &DIDDocument{
+			ID:      uuid.NewString(),
+			Context: contexts,
+		},
+	}
+}
+
+// Builds the DID Document
+func (builder *DIDDocumentBuilder) Build() (*DIDDocument, error) {
+	if builder.IsEmpty() {
+		return nil, errors.New(BuilderEmptyError)
+	}
+
+	if err := builder.DIDDocument.IsValid(); err != nil {
+		return nil, errors.Wrap(err, "did doc not valid")
+	}
+
+	return builder.DIDDocument, nil
+}
+
+func (builder *DIDDocumentBuilder) IsEmpty() bool {
+	if builder == nil || builder.DIDDocument == nil {
+		return true
+	}
+	return reflect.DeepEqual(builder, &DIDDocumentBuilder{})
+}
+
+func (builder *DIDDocumentBuilder) AddContext(context interface{}) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	res, err := util.InterfaceToStrings(context)
+	if err != nil {
+		return errors.Wrap(err, "malformed context")
+	}
+	uniqueContexts := util.MergeUniqueValues(builder.contexts, res)
+	builder.contexts = uniqueContexts
+	builder.Context = uniqueContexts
+	return nil
+}
+
+func (builder *DIDDocumentBuilder) SetID(id string) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+
+	builder.ID = id
+	return nil
+}
+
+func (builder *DIDDocumentBuilder) SetAlsoKnownAs(name string) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.AlsoKnownAs = name
+	return nil
+}
+
+func (builder *DIDDocumentBuilder) SetController(controller string) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.Controller = controller
+	return nil
+}
+
+// Note: Not thread safe
+func (builder *DIDDocumentBuilder) AddVerificationMethod(m VerificationMethod) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.VerificationMethod = append(builder.VerificationMethod, m)
+	return nil
+}
+
+// Note: Not thread safe
+func (builder *DIDDocumentBuilder) AddAuthentication(m VerificationMethodSet) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.Authentication = append(builder.Authentication, m)
+	return nil
+}
+
+// Note: Not thread safe
+func (builder *DIDDocumentBuilder) AddAssertionMethod(m VerificationMethodSet) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.AssertionMethod = append(builder.AssertionMethod, m)
+	return nil
+}
+
+// Note: Not thread safe
+func (builder *DIDDocumentBuilder) AddKeyAgreement(m VerificationMethodSet) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.KeyAgreement = append(builder.KeyAgreement, m)
+	return nil
+}
+
+// Note: Not thread safe
+func (builder *DIDDocumentBuilder) AddCapabilityInvocation(m VerificationMethodSet) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.CapabilityInvocation = append(builder.CapabilityInvocation, m)
+	return nil
+}
+
+// Note: Not thread safe
+func (builder *DIDDocumentBuilder) AddCapabilityDelgation(m VerificationMethodSet) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.CapabilityDelegation = append(builder.CapabilityDelegation, m)
+	return nil
+}
+
+// Note: Not thread safe
+func (builder *DIDDocumentBuilder) AddService(s Service) error {
+	if builder.IsEmpty() {
+		return errors.New(BuilderEmptyError)
+	}
+	builder.Services = append(builder.Services, s)
+	return nil
+}

did/builder_test.go

@@ -0,0 +1,138 @@
+package did
+
+import (
+	"testing"
+
+	"github.com/TBD54566975/ssi-sdk/crypto"
+	"github.com/stretchr/testify/assert"
+)
+
+// Exercise all builder methods
+func TestDIDDocumentBuilder(t *testing.T) {
+	// https://www.w3.org/TR/did-core/#example-did-document-with-1-verification-method-type
+	exampleAuthenticationEntry := map[string]string{
+		"id":                 "did:example:123#z6MkecaLyHuYWkayBDLw5ihndj3T1m6zKTGqau3A51G7RBf3",
+		"type":               "Ed25519VerificationKey2020",
+		"controller":         "did:example:123",
+		"publicKeyMultibase": "zAKJP3f7BD6W4iWEQ9jwndVTCBq8ua2Utt8EEjJ6Vxsf",
+	}
+
+	exampleCapabilityInvocationEntry := map[string]string{
+		"id":                 "did:example:123#z6MkhdmzFu659ZJ4XKj31vtEDmjvsi5yDZG5L7Caz63oP39k",
+		"type":               "Ed25519VerificationKey2020",
+		"controller":         "did:example:123",
+		"publicKeyMultibase": "z4BWwfeqdp1obQptLLMvPNgBw48p7og1ie6Hf9p5nTpNN",
+	}
+
+	exampleAssertionEntry := map[string]string{
+		"id":                 "did:example:123#z6MkiukuAuQAE8ozxvmahnQGzApvtW7KT5XXKfojjwbdEomY",
+		"type":               "Ed25519VerificationKey2020",
+		"controller":         "did:example:123",
+		"publicKeyMultibase": "z5TVraf9itbKXrRvt2DSS95Gw4vqU3CHAdetoufdcKazA",
+	}
+
+	exampleCapabilityDelegationEntry := map[string]string{
+		"id":                 "did:example:123#z6Mkw94ByR26zMSkNdCUi6FNRsWnc2DFEeDXyBGJ5KTzSWyi",
+		"type":               "Ed25519VerificationKey2020",
+		"controller":         "did:example:123",
+		"publicKeyMultibase": "zHgo9PAmfeoxHG8Mn2XHXamxnnSwPpkyBHAMNF3VyXJCL",
+	}
+
+	// https://www.w3.org/TR/did-core/#example-did-document-with-many-different-key-types
+	exampleVerificationMethod := VerificationMethod{
+		ID:         "did:example:123#key-0",
+		Type:       "JsonWebKey2020",
+		Controller: "did:example:123",
+		PublicKeyJWK: &crypto.PublicKeyJWK{
+			KTY: "OKP",
+			CRV: "Ed25519",
+			X:   "VCpo2LMLhn6iWku8MKvSLg2ZAoC-nlOyPVQaO3FxVeQ",
+		},
+	}
+
+	// https://www.w3.org/TR/did-core/#example-key-agreement-property-containing-two-verification-methods
+	exampleKeyAgreementEntry := map[string]string{
+		"id":                 "did:example:123#zC9ByQ8aJs8vrNXyDhPHHNNMSHPcaSgNpjjsBYpMMjsTdS",
+		"type":               "X25519KeyAgreementKey2019",
+		"controller":         "did:example:123",
+		"publicKeyMultibase": "z9hFgmPVfmBZwRvFEyniQDBkz9LmV7gDEqytWyGZLmDXE",
+	}
+
+	var builderBad DIDDocumentBuilder
+	_, err := builderBad.Build()
+	assert.Error(t, err)
+	notReadyErr := "builder cannot be empty"
+	assert.Contains(t, err.Error(), notReadyErr)
+	err = builderBad.AddContext("https://w3id.org/did/v1")
+	assert.Error(t, err)
+
+	builder := NewDIDDocumentBuilder()
+	_, err = builder.Build()
+	assert.NoError(t, err)
+	assert.False(t, builder.IsEmpty())
+
+	// default context should be set
+	assert.NotEmpty(t, builder.Context)
+
+	// set context of a bad type
+	err = builder.AddContext(4)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "malformed context")
+
+	// correct context
+	err = builder.AddContext("https://w3id.org/did/v1")
+	assert.NoError(t, err)
+
+	// there is a default id
+	assert.NotEmpty(t, builder.ID)
+
+	// set id
+	id := "test-id"
+	err = builder.SetID(id)
+	assert.NoError(t, err)
+
+	// set also known as
+	err = builder.SetAlsoKnownAs("aka")
+	assert.NoError(t, err)
+
+	// TODO: Fix test methods
+	// set controller
+	err = builder.SetController("controller")
+	assert.NoError(t, err)
+
+	// valid type as a []string
+	err = builder.AddAuthentication(exampleAuthenticationEntry)
+	assert.NoError(t, err)
+
+	// set issuer as a string
+	err = builder.AddAssertionMethod(exampleAssertionEntry)
+	assert.NoError(t, err)
+
+	// set issuer as a string
+	err = builder.AddKeyAgreement(exampleKeyAgreementEntry)
+	assert.NoError(t, err)
+
+	err = builder.AddCapabilityInvocation(exampleCapabilityInvocationEntry)
+	assert.NoError(t, err)
+
+	err = builder.AddCapabilityDelgation(exampleCapabilityDelegationEntry)
+	assert.NoError(t, err)
+
+	err = builder.AddVerificationMethod(exampleVerificationMethod)
+	assert.NoError(t, err)
+
+	err = builder.AddService(
+		Service{
+			ID:              "did:example:123#linked-domain",
+			Type:            "LinkedDomains",
+			ServiceEndpoint: "https://bar.example.com",
+		})
+
+	assert.NoError(t, err)
+
+	// build it and verify some values
+	cred, err := builder.Build()
+	assert.NoError(t, err)
+	assert.NotEmpty(t, cred)
+	assert.Equal(t, id, cred.ID)
+}