feat: Add support for vctm header (#32)

* feat: Add support for vctm header

* removed deprecated createVCSDJWT method

Author: vijayshiyani

CHANGELOG.md

@@ -7,11 +7,19 @@ and this project (loosely) adheres to [Semantic Versioning](https://semver.org/s
 
 ## 2.0.0 - 2025-XX-XX
 
+### Added
+
+- Support embedding Type Metadata documents in the JWS unprotected header via the `vctm` parameter, as per [SD-JWT VC Spec Section 6.3.5](https://www.ietf.org/archive/id/draft-ietf-oauth-sd-jwt-vc-05.html#section-6.3.5).
+
 ### Changed
 
 - The `typ` header for issued SD-JWT VCs is now `dc+sd-jwt` as per [draft-08](https://www.ietf.org/archive/id/draft-ietf-oauth-sd-jwt-vc-08.html#section-3.2.1)
 - The `Verifier` will accept both `vc+sd-jwt` and `dc+sd-jwt`.
 
+### Removed
+
+- Removed deprecated `createVCSDJWT` method from the `Issuer` class. Use `createSignedVCSDJWT` instead.
+
 ## 1.3.0 - 2024-10-07
 
 ### Security

src/issuer.spec.ts

@@ -1,6 +1,5 @@
+import { DisclosureFrame, base64decode, decodeDisclosures, decodeJWT } from '@meeco/sd-jwt';
 import { generateKeyPair } from 'jose';
-
-import { DisclosureFrame, decodeDisclosures, decodeJWT } from '@meeco/sd-jwt';
 import { Issuer } from './issuer';
 import { hasherCallbackFn, signerCallbackFn } from './test-utils/helpers';
 import {
@@ -70,7 +69,13 @@ describe('Issuer', () => {
       ],
     };
 
-    const VCSDJwt = await issuer.createVCSDJWT(vcClaims, payload, sdVCClaimsDisclosureFrame, undefined, sdVCHeader);
+    const VCSDJwt = await issuer.createSignedVCSDJWT({
+      vcClaims,
+      sdJWTPayload: payload,
+      sdVCClaimsDisclosureFrame,
+      saltGenerator: undefined,
+      sdJWTHeader: sdVCHeader,
+    });
 
     expect(VCSDJwt).toBeDefined();
     expect(typeof VCSDJwt).toBe('string');
@@ -117,6 +122,45 @@ describe('Issuer', () => {
     expect(jwtHeader.typ).toEqual(ValidTypValues.DCSDJWT);
   });
 
+  it('should embed type metadata in vctm header when provided', async () => {
+    const payload: CreateSDJWTPayload = {
+      iat: Math.floor(Date.now() / 1000),
+      cnf: { jwk: { kty: 'EC', crv: 'P-256', x: 'x', y: 'y' } },
+      iss: 'https://valid.issuer.url',
+      vct: 'test_vct_for_vctm',
+    };
+    const vcClaims: VCClaims = { data: 'some_claim_data' };
+    const typeMetadataDoc1 = { vct: 'test_vct_for_vctm', name: 'Test Credential Type 1' };
+    const typeMetadataDoc2String = JSON.stringify({ vct: 'test_vct_for_vctm_extended', name: 'Extended Type' });
+
+    const VCSDJwtWithVctm = await issuer.createSignedVCSDJWT({
+      vcClaims,
+      sdJWTPayload: payload,
+      typeMetadataGlueDocuments: [typeMetadataDoc1, typeMetadataDoc2String],
+    });
+
+    const { header: headerWithVctm } = decodeJWT(VCSDJwtWithVctm.split(SD_JWT_FORMAT_SEPARATOR).shift() || '');
+    expect(headerWithVctm.vctm).toBeDefined();
+    expect(Array.isArray(headerWithVctm.vctm)).toBe(true);
+
+    expect((headerWithVctm.vctm as any[]).length).toBe(2);
+
+    const decodedDoc1 = JSON.parse(base64decode((headerWithVctm.vctm as any[])[0]));
+
+    const decodedDoc2 = JSON.parse(base64decode((headerWithVctm.vctm as any[])[1]));
+
+    expect(decodedDoc1).toEqual(typeMetadataDoc1);
+    expect(decodedDoc2).toEqual(JSON.parse(typeMetadataDoc2String));
+
+    // Test without vctm
+    const VCSDJwtWithoutVctm = await issuer.createSignedVCSDJWT({
+      vcClaims,
+      sdJWTPayload: payload,
+    });
+    const { header: headerWithoutVctm } = decodeJWT(VCSDJwtWithoutVctm.split(SD_JWT_FORMAT_SEPARATOR).shift() || '');
+    expect(headerWithoutVctm.vctm).toBeUndefined();
+  });
+
   describe('Issuer', () => {
     describe('constructor', () => {
       it('should throw an error if signer callback is not provided', () => {

src/issuer.ts

@@ -1,14 +1,6 @@
-import { DisclosureFrame, JWTHeaderParameters, SDJWTPayload, SaltGenerator, issueSDJWT } from '@meeco/sd-jwt';
+import { DisclosureFrame, JWTHeaderParameters, SDJWTPayload, base64encode, issueSDJWT } from '@meeco/sd-jwt';
 import { SDJWTVCError } from './errors.js';
-import {
-  CreateSDJWTPayload,
-  CreateSignedJWTOpts,
-  HasherConfig,
-  JWT,
-  ReservedJWTClaimKeys,
-  SignerConfig,
-  VCClaims,
-} from './types.js';
+import { CreateSignedJWTOpts, HasherConfig, JWT, ReservedJWTClaimKeys, SignerConfig, VCClaims } from './types.js';
 import { ValidTypValues, isValidUrl } from './util.js';
 
 export class Issuer {
@@ -42,58 +34,48 @@ export class Issuer {
     return this.hasher;
   }
 
-  /**
-   * Creates a VC SD-JWT.
-   * @deprecated This method will be removed in the next version. Use `createSignedVCSDJWT` instead.
-   * @param claims The VC claims.
-   * @param sdJWTPayload The SD-JWT payload.
-   * @param sdVCClaimsDisclosureFrame The SD-VC claims disclosure frame.
-   * @param saltGenerator The salt generator.
-   * @param sdJWTHeader additional header parameters
-   * @throws An error if the VC SD-JWT cannot be created.
-   * @returns The VC SD-JWT.
-   */
-  async createVCSDJWT(
-    vcClaims: VCClaims,
-    sdJWTPayload: CreateSDJWTPayload,
-    sdVCClaimsDisclosureFrame: DisclosureFrame = {},
-    saltGenerator?: SaltGenerator,
-    sdJWTHeader?: Omit<JWTHeaderParameters, 'typ' | 'alg'>,
-  ): Promise<JWT> {
-    return this.createSignedVCSDJWT({ vcClaims, sdJWTPayload, sdVCClaimsDisclosureFrame, saltGenerator, sdJWTHeader });
-  }
-
   /**
    * Creates a signed SD-JWT VC.
    */
   async createSignedVCSDJWT(opts: CreateSignedJWTOpts): Promise<JWT> {
-    const { vcClaims, sdJWTPayload, sdVCClaimsDisclosureFrame = {}, saltGenerator, sdJWTHeader } = opts;
+    const {
+      vcClaims,
+      sdJWTPayload,
+      sdVCClaimsDisclosureFrame = {},
+      saltGenerator,
+      sdJWTHeader,
+      typeMetadataGlueDocuments,
+    } = opts;
     if (!vcClaims) throw new SDJWTVCError('vcClaims is required');
     if (!sdJWTPayload) throw new SDJWTVCError('sdJWTPayload is required');
 
     this.validateVCClaims(vcClaims as VCClaims);
     this.validateSDJWTPayload(sdJWTPayload);
     this.validateSDVCClaimsDisclosureFrame(sdVCClaimsDisclosureFrame);
 
+    const header: JWTHeaderParameters & { vctm?: string[] } = {
+      ...sdJWTHeader,
+      typ: Issuer.SD_JWT_TYP,
+      alg: this.signer.alg,
+    };
+
+    if (typeMetadataGlueDocuments && typeMetadataGlueDocuments.length > 0) {
+      header.vctm = typeMetadataGlueDocuments.map((doc) => {
+        const docString = typeof doc === 'string' ? doc : JSON.stringify(doc);
+        return base64encode(docString);
+      });
+    }
+
     try {
-      const jwt = await issueSDJWT(
-        {
-          ...sdJWTHeader,
-          typ: Issuer.SD_JWT_TYP,
-          alg: this.signer.alg,
-        },
-        { ...sdJWTPayload, ...vcClaims },
-        sdVCClaimsDisclosureFrame,
-        {
-          signer: this.signer.callback,
-          hash: {
-            alg: this.hasher.alg,
-            callback: this.hasher.callback,
-          },
-          cnf: sdJWTPayload?.cnf,
-          generateSalt: saltGenerator,
+      const jwt = await issueSDJWT(header, { ...sdJWTPayload, ...vcClaims }, sdVCClaimsDisclosureFrame, {
+        signer: this.signer.callback,
+        hash: {
+          alg: this.hasher.alg,
+          callback: this.hasher.callback,
         },
-      );
+        cnf: sdJWTPayload?.cnf,
+        generateSalt: saltGenerator,
+      });
 
       return jwt;
     } catch (error: any) {

src/types.ts

@@ -31,6 +31,7 @@ export interface CreateSignedJWTOpts {
   sdVCClaimsDisclosureFrame?: DisclosureFrame;
   saltGenerator?: SaltGenerator;
   sdJWTHeader?: Omit<JWTHeaderParameters, 'typ' | 'alg'>;
+  typeMetadataGlueDocuments?: Array<Record<string, any> | string>;
 }
 
 export interface PresentSDJWTPayload extends JWTPayload {