feat: add SD JWT credential format support

Signed-off-by: Mykhailo Sizov <[email protected]>

component/models/sdjwt/common/common.go

@@ -293,6 +293,10 @@ func GetSDAlg(claims map[string]interface{}) (string, error) {
 
 // GetKeyFromVC returns key value from VC.
 func GetKeyFromVC(key string, claims map[string]interface{}) (interface{}, bool) {
+ if obj, ok := claims[key]; ok {
+ return obj, true
+ }
+
  vcObj, ok := claims["vc"]
  if !ok {
  return nil, false

component/models/sdjwt/issuer/issuer.go

@@ -98,6 +98,8 @@ type newOpts struct {
  addDecoyDigests bool
  structuredClaims bool
 
+ sdjwtCredentialFormat bool
+
  nonSDClaimsMap map[string]bool
 }
 
@@ -202,6 +204,17 @@ func WithStructuredClaims(flag bool) NewOpt {
  }
 }
 
+// WithSDJWTCredentialFormat is an option that declares the SDJWT credential format.
+// Key difference with default format is that underlying object does not contain custom "vc" root claim.
+// Example:
+//
+// https://www.ietf.org/archive/id/draft-ietf-oauth-selective-disclosure-jwt-05.html#name-example-4b-w3c-verifiable-c.
+func WithSDJWTCredentialFormat(flag bool) NewOpt {
+ return func(opts *newOpts) {
+ opts.sdjwtCredentialFormat = flag
+ }
+}
+
 // WithNonSelectivelyDisclosableClaims is an option for provide claim names that should be ignored when creating
 // selectively disclosable claims.
 // For example if you would like to not selectively disclose id and degree type from the following claims:
@@ -289,6 +302,12 @@ Algorithm:
 */
 func NewFromVC(vc map[string]interface{}, headers jose.Headers,
  signer jose.Signer, opts ...NewOpt) (*SelectiveDisclosureJWT, error) {
+ nOpts := &newOpts{}
+
+ for _, opt := range opts {
+ opt(nOpts)
+ }
+
  csObj, ok := common.GetKeyFromVC(credentialSubjectKey, vc)
  if !ok {
  return nil, fmt.Errorf("credential subject not found")
@@ -304,20 +323,29 @@ func NewFromVC(vc map[string]interface{}, headers jose.Headers,
  return nil, err
  }
 
+ var vcClaims = vc
+ if !nOpts.sdjwtCredentialFormat {
+ // Since it's not SD JWT credential format - need to consider "vc" underlying object
+ vcClaims, ok = vc[vcKey].(map[string]interface{})
+ if !ok {
+ return nil, errors.New("invalid vc claim")
+ }
+ }
+
  selectiveCredentialSubject := utils.CopyMap(token.SignedJWT.Payload)
  // move _sd_alg key from credential subject to vc as per example 4 in spec
- vc[vcKey].(map[string]interface{})[common.SDAlgorithmKey] = selectiveCredentialSubject[common.SDAlgorithmKey]
+ vcClaims[common.SDAlgorithmKey] = selectiveCredentialSubject[common.SDAlgorithmKey]
  delete(selectiveCredentialSubject, common.SDAlgorithmKey)
 
  // move cnf key from credential subject to vc as per example 4 in spec
  cnfObj, ok := selectiveCredentialSubject[common.CNFKey]
  if ok {
- vc[vcKey].(map[string]interface{})[common.CNFKey] = cnfObj
+ vcClaims[common.CNFKey] = cnfObj
  delete(selectiveCredentialSubject, common.CNFKey)
  }
 
  // update VC with 'selective' credential subject
- vc[vcKey].(map[string]interface{})[credentialSubjectKey] = selectiveCredentialSubject
+ vcClaims[credentialSubjectKey] = selectiveCredentialSubject
 
  // sign VC with 'selective' credential subject
  signedJWT, err := afgjwt.NewSigned(vc, headers, signer)
@@ -478,7 +506,9 @@ func createDisclosuresAndDigests(path string, claims map[string]interface{}, opt
  return nil, nil, err
  }
 
- digestsMap[common.SDKey] = digests
+ if len(digests) > 0 {
+ digestsMap[common.SDKey] = digests
+ }
 
  return disclosures, digestsMap, nil
 }

component/models/sdjwt/issuer/issuer_test.go

@@ -580,6 +580,50 @@ func TestNewFromVC(t *testing.T) {
  r.Contains(err.Error(), "unknown key id")
  })
 
+ t.Run("success - structured claims + holder binding + SD JWT credential format", func(t *testing.T) {
+ holderPublicKey, _, err := ed25519.GenerateKey(rand.Reader)
+ r.NoError(err)
+
+ holderPublicJWK, err := jwksupport.JWKFromKey(holderPublicKey)
+ require.NoError(t, err)
+
+ // create VC - we will use template here
+ var vc map[string]interface{}
+ err = json.Unmarshal([]byte(sampleSDJWTVCFull), &vc)
+ r.NoError(err)
+
+ token, err := NewFromVC(vc, nil, signer,
+ WithHolderPublicKey(holderPublicJWK),
+ WithStructuredClaims(true),
+ WithNonSelectivelyDisclosableClaims([]string{"id", "degree.type"}),
+ WithSDJWTCredentialFormat(true))
+ r.NoError(err)
+
+ vcCombinedFormatForIssuance, err := token.Serialize(false)
+ r.NoError(err)
+
+ fmt.Println(fmt.Sprintf("issuer SD-JWT: %s", vcCombinedFormatForIssuance))
+
+ var vcWithSelectedDisclosures map[string]interface{}
+ err = token.DecodeClaims(&vcWithSelectedDisclosures)
+ r.NoError(err)
+
+ printObject(t, "VC with selected disclosures", vcWithSelectedDisclosures)
+
+ id, err := jsonpath.Get("$.credentialSubject.id", vcWithSelectedDisclosures)
+ r.NoError(err)
+ r.Equal("did:example:ebfeb1f712ebc6f1c276e12ec21", id)
+
+ degreeType, err := jsonpath.Get("$.credentialSubject.degree.type", vcWithSelectedDisclosures)
+ r.NoError(err)
+ r.Equal("BachelorDegree", degreeType)
+
+ degreeID, err := jsonpath.Get("$.credentialSubject.degree.id", vcWithSelectedDisclosures)
+ r.Error(err)
+ r.Nil(degreeID)
+ r.Contains(err.Error(), "unknown key id")
+ })
+
  t.Run("success - flat claims + holder binding", func(t *testing.T) {
  holderPublicKey, _, err := ed25519.GenerateKey(rand.Reader)
  r.NoError(err)
@@ -1014,3 +1058,32 @@ const sampleVCFull = `
  "type": "VerifiableCredential"
  }
 }`
+
+const sampleSDJWTVCFull = `
+{
+ "iat": 1673987547,
+ "iss": "did:example:76e12ec712ebc6f1c221ebfeb1f",
+ "jti": "http://example.edu/credentials/1872",
+ "nbf": 1673987547,
+ "sub": "did:example:ebfeb1f712ebc6f1c276e12ec21",
+ "@context": [
+ "https://www.w3.org/2018/credentials/v1"
+ ],
+ "credentialSubject": {
+ "degree": {
+ "degree": "MIT",
+ "type": "BachelorDegree",
+ "id": "some-id"
+ },
+ "name": "Jayden Doe",
+ "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
+ "spouse": "did:example:c276e12ec21ebfeb1f712ebc6f1"
+ },
+ "first_name": "First name",
+ "id": "http://example.edu/credentials/1872",
+ "info": "Info",
+ "issuanceDate": "2023-01-17T22:32:27.468109817+02:00",
+ "issuer": "did:example:76e12ec712ebc6f1c221ebfeb1f",
+ "last_name": "Last name",
+ "type": "VerifiableCredential"
+}`

component/models/verifiable/credential_jwt.go

@@ -32,6 +32,49 @@ type JWTCredClaims struct {
  VC map[string]interface{} `json:"vc,omitempty"`
 }
 
+// ToSDJWTCredentialPayload defines custom marshalling of JWTCredClaims.
+// Key difference with default marshaller is that returned object does not contain custom "vc" root claim.
+// Example:
+//
+// https://www.ietf.org/archive/id/draft-ietf-oauth-selective-disclosure-jwt-05.html#name-example-4b-w3c-verifiable-c.
+func (jcc *JWTCredClaims) ToSDJWTCredentialPayload() ([]byte, error) {
+ type Alias JWTCredClaims
+
+ alias := Alias(*jcc)
+
+ vcMap := alias.VC
+
+ alias.VC = nil
+
+ data, err := jsonutil.MarshalWithCustomFields(alias, vcMap)
+ if err != nil {
+ return nil, fmt.Errorf("marshal JWTW3CCredClaims: %w", err)
+ }
+
+ return data, nil
+}
+
+// UnmarshalJSON defines custom unmarshalling of JWTCredClaims from JSON.
+// For SD-JWT case, it supports both v2 and v5 formats.
+func (jcc *JWTCredClaims) UnmarshalJSON(data []byte) error {
+ type Alias JWTCredClaims
+
+ alias := (*Alias)(jcc)
+
+ customFields := make(CustomFields)
+
+ err := jsonutil.UnmarshalWithCustomFields(data, alias, customFields)
+ if err != nil {
+ return fmt.Errorf("unmarshal JWTCredClaims: %w", err)
+ }
+
+ if len(customFields) > 0 && len(alias.VC) == 0 {
+ alias.VC = customFields
+ }
+
+ return nil
+}
+
 // newJWTCredClaims creates JWT Claims of VC with an option to minimize certain fields of VC
 // which is put into "vc" claim.
 func newJWTCredClaims(vc *Credential, minimizeVC bool) (*JWTCredClaims, error) {

component/models/verifiable/credential_jwt_test.go

@@ -6,6 +6,7 @@ SPDX-License-Identifier: Apache-2.0
 package verifiable
 
 import (
+ "encoding/json"
  "errors"
  "testing"
  "time"
@@ -53,3 +54,45 @@ func TestRefineVcFromJwtClaims(t *testing.T) {
  require.Equal(t, "2019-08-10T00:00:00Z", vcMap["issuanceDate"])
  require.Equal(t, "2029-08-10T00:00:00Z", vcMap["expirationDate"])
 }
+
+func TestJWTCredClaims_ToSDJWTCredentialPayload(t *testing.T) {
+ jcc := &JWTCredClaims{
+ Claims: &jwt.Claims{
+ Issuer: "issuer",
+ Subject: "subject",
+ Audience: josejwt.Audience{"leela", "fry"},
+ NotBefore: josejwt.NewNumericDate(time.Date(2016, 1, 1, 0, 0, 0, 0, time.UTC)),
+ ID: "http://example.edu/credentials/3732",
+ },
+ VC: map[string]interface{}{
+ "@context": []interface{}{
+ "https://www.w3.org/2018/credentials/v1",
+ "https://trustbloc.github.io/context/vc/examples-v1.jsonld",
+ },
+ "id": "http://example.edu/credentials/1989",
+ "type": "VerifiableCredential",
+ "credentialSubject": map[string]interface{}{
+ "id": "did:example:iuajk1f712ebc6f1c276e12ec21",
+ },
+ "issuer": map[string]interface{}{
+ "id": "did:example:09s12ec712ebc6f1c671ebfeb1f",
+ "name": "Example University",
+ },
+ "issuanceDate": "2020-01-01T10:54:01Z",
+ "credentialStatus": map[string]interface{}{
+ "id": "https://example.gov/status/65",
+ "type": "CredentialStatusList2017",
+ },
+ },
+ }
+
+ got, err := jcc.ToSDJWTCredentialPayload()
+ require.NoError(t, err)
+ require.NotContains(t, string(got), `"vc"`)
+
+ var jccMapped *JWTCredClaims
+ err = json.Unmarshal(got, &jccMapped)
+ require.NoError(t, err)
+
+ require.Equal(t, jcc, jccMapped)
+}

component/models/verifiable/credential_sdjwt.go

@@ -236,7 +236,8 @@ func filterDisclosures(
 }
 
 type makeSDJWTOpts struct {
- hashAlg crypto.Hash
+ hashAlg crypto.Hash
+ sdjwtCredentialPayloadFormat bool
 }
 
 // MakeSDJWTOption provides an option for creating an SD-JWT from a VC.
@@ -249,6 +250,17 @@ func MakeSDJWTWithHash(hash crypto.Hash) MakeSDJWTOption {
  }
 }
 
+// WithSDJWTCredentialPayloadFormat sets the payload format in SD-JWT VC.
+// Key difference with default format is that returned object does not contain custom "vc" root claim.
+// Example:
+//
+// https://www.ietf.org/archive/id/draft-ietf-oauth-selective-disclosure-jwt-05.html#name-example-4b-w3c-verifiable-c.
+func WithSDJWTCredentialPayloadFormat() MakeSDJWTOption {
+ return func(opts *makeSDJWTOpts) {
+ opts.sdjwtCredentialPayloadFormat = true
+ }
+}
+
 // MakeSDJWT creates an SD-JWT in combined format for issuance, with all fields in credentialSubject converted
 // recursively into selectively-disclosable SD-JWT claims.
 func (vc *Credential) MakeSDJWT(signer jose.Signer, signingKeyID string, options ...MakeSDJWTOption) (string, error) {
@@ -278,7 +290,13 @@ func makeSDJWT(vc *Credential, signer jose.Signer, signingKeyID string, options
  return nil, fmt.Errorf("constructing VC JWT claims: %w", err)
  }
 
- claimBytes, err := json.Marshal(claims)
+ var claimBytes []byte
+ if opts.sdjwtCredentialPayloadFormat {
+ claimBytes, err = claims.ToSDJWTCredentialPayload()
+ } else {
+ claimBytes, err = json.Marshal(claims)
+ }
+
  if err != nil {
  return nil, err
  }
@@ -297,6 +315,7 @@ func makeSDJWT(vc *Credential, signer jose.Signer, signingKeyID string, options
  issuerOptions := []issuer.NewOpt{
  issuer.WithStructuredClaims(true),
  issuer.WithNonSelectivelyDisclosableClaims([]string{"id"}),
+ issuer.WithSDJWTCredentialFormat(opts.sdjwtCredentialPayloadFormat),
  }
 
  if opts.hashAlg != 0 {

component/models/verifiable/credential_sdjwt_test.go

@@ -37,6 +37,15 @@ func TestParseSDJWT(t *testing.T) {
  require.NotNil(t, newVC)
  })
 
+ t.Run("success with SD JWT credential payload format", func(t *testing.T) {
+ sdJWTCredFormatString, issuerCredFormatID := createTestSDJWTCred(t, privKey, WithSDJWTCredentialPayloadFormat())
+
+ newVC, e := ParseCredential([]byte(sdJWTCredFormatString),
+ WithPublicKeyFetcher(createDIDKeyFetcher(t, pubKey, issuerCredFormatID)))
+ require.NoError(t, e)
+ require.NotNil(t, newVC)
+ })
+
  t.Run("success with sd alg in subject", func(t *testing.T) {
  vc, e := ParseCredential([]byte(sdJWTString), WithDisabledProofCheck())
  require.NoError(t, e)
@@ -306,6 +315,15 @@ func TestMakeSDJWT(t *testing.T) {
  require.NoError(t, err)
  })
 
+ t.Run("with SD JWT credential payload format", func(t *testing.T) {
+ sdjwt, err := vc.MakeSDJWT(
+ afgojwt.NewEd25519Signer(privKey), "did:example:abc123#key-1", WithSDJWTCredentialPayloadFormat())
+ require.NoError(t, err)
+
+ _, err = ParseCredential([]byte(sdjwt), WithPublicKeyFetcher(holderPublicKeyFetcher(pubKey)))
+ require.NoError(t, err)
+ })
+
  t.Run("with hash option", func(t *testing.T) {
  sdjwt, err := vc.MakeSDJWT(afgojwt.NewEd25519Signer(privKey), "did:example:abc123#key-1",
  MakeSDJWTWithHash(crypto.SHA512))
@@ -510,15 +528,16 @@ func (m *mockSigner) Headers() jose.Headers {
  return jose.Headers{"alg": "foo"}
 }
 
-func createTestSDJWTCred(t *testing.T, privKey ed25519.PrivateKey) (sdJWTCred string, issuerID string) {
+func createTestSDJWTCred(
+ t *testing.T, privKey ed25519.PrivateKey, opts ...MakeSDJWTOption) (sdJWTCred string, issuerID string) {
  t.Helper()
 
  testCred := []byte(jwtTestCredential)
 
  srcVC, err := parseTestCredential(t, testCred)
  require.NoError(t, err)
 
- sdjwt, err := srcVC.MakeSDJWT(afgojwt.NewEd25519Signer(privKey), srcVC.Issuer.ID+"#keys-1")
+ sdjwt, err := srcVC.MakeSDJWT(afgojwt.NewEd25519Signer(privKey), srcVC.Issuer.ID+"#keys-1", opts...)
  require.NoError(t, err)
 
  return sdjwt, srcVC.Issuer.ID

go.mod

@@ -79,3 +79,5 @@ require (
  gopkg.in/yaml.v3 v3.0.1 // indirect
  rsc.io/tmplfunc v0.0.3 // indirect
 )
+
+replace github.com/hyperledger/aries-framework-go/component/models => ./component/models

go.sum

@@ -79,8 +79,6 @@ github.com/hyperledger/aries-framework-go/component/kmscrypto v0.0.0-20230622082
 github.com/hyperledger/aries-framework-go/component/kmscrypto v0.0.0-20230622082138-3ffab1691857/go.mod h1:xgNlHAVQjqwoknzHbXkeHkAJgUxRWKfHXPT3nhVhH3Q=
 github.com/hyperledger/aries-framework-go/component/log v0.0.0-20230427134832-0c9969493bd3 h1:x5qFQraTX86z9GCwF28IxfnPm6QH5YgHaX+4x97Jwvw=
 github.com/hyperledger/aries-framework-go/component/log v0.0.0-20230427134832-0c9969493bd3/go.mod h1:CvYs4l8X2NrrF93weLOu5RTOIJeVdoZITtjEflyuTyM=
-github.com/hyperledger/aries-framework-go/component/models v0.0.0-20230622171716-43af8054a539 h1:3wjwGDB4/D2z4lZexGtD8tf13KRy/jiXqI9mtiEHmUo=
-github.com/hyperledger/aries-framework-go/component/models v0.0.0-20230622171716-43af8054a539/go.mod h1:Qklxf9WG44vpLGF+Efs1aCWeHhsVOU0HFvEslf0RDrQ=
 github.com/hyperledger/aries-framework-go/component/storage/edv v0.0.0-20221025204933-b807371b6f1e h1:/hrQfwJvHJrwV2FSmfnRp5L6yKY9DqDFqwYyb+oVuDU=
 github.com/hyperledger/aries-framework-go/component/storage/edv v0.0.0-20221025204933-b807371b6f1e/go.mod h1:ACGP1L+WeecDtyA0Mi2E1kqtPLIGrCWPSJ43q2elwX8=
 github.com/hyperledger/aries-framework-go/component/storageutil v0.0.0-20230427134832-0c9969493bd3 h1:JGYA9l5zTlvsvfnXT9hYPpCokAjmVKX0/r7njba7OX4=