[openwallet-foundation#26]Provide custom header in issue API (openwal…

…let-foundation#27)

Signed-off-by: Lukas <[email protected]>

examples/custom_header.ts

@@ -0,0 +1,27 @@
+import sdjwt, { DisclosureFrame } from '@hopae/sd-jwt';
+import Crypto from 'node:crypto';
+
+export const createKeyPair = () => {
+  const { privateKey, publicKey } = Crypto.generateKeyPairSync('ed25519');
+  return { privateKey, publicKey };
+};
+
+(async () => {
+  const { privateKey, publicKey } = createKeyPair();
+  const claims = {
+    firstname: 'John',
+    lastname: 'Doe',
+    ssn: '123-45-6789',
+    id: '1234',
+  };
+  const disclosureFrame: DisclosureFrame<typeof claims> = {
+    _sd: ['firstname', 'id'],
+  };
+
+  const encodedSdjwt = await sdjwt.issue(claims, privateKey, disclosureFrame, {
+    header: { typ: 'vc+sd-jwt', custom: 'data' },
+  });
+  console.log('encodedSdjwt:', encodedSdjwt);
+  const sdjwttoken = sdjwt.decode(encodedSdjwt);
+  console.log(sdjwttoken);
+})();

examples/package.json

@@ -11,7 +11,8 @@
     "validate": "ts-node validate.ts",
     "verify": "ts-node verify.ts",
     "custom": "ts-node custom.ts",
-    "decoy": "ts-node decoy.ts"
+    "decoy": "ts-node decoy.ts",
+    "custom_header": "ts-node custom_header.ts"
   },
   "keywords": [],
   "author": "",

src/index.ts

@@ -64,6 +64,7 @@ export class SDJwtInstance {
     privateKey: Uint8Array | KeyLike,
     disclosureFrame?: DisclosureFrame<Payload>,
     options?: {
+      header?: object;
       sign_alg?: string;
       hash_alg?: string;
       kb?: {
@@ -85,7 +86,11 @@ export class SDJwtInstance {
       this.userConfig.saltGenerator ?? defaultConfig.saltGenerator,
     );
     const alg = options?.sign_alg ?? SDJwtInstance.DEFAULT_ALG;
-    const header = this.userConfig.omitTyp ? { alg } : { alg, typ: SD_JWT_TYP };
+    const OptionHeader = options?.header ?? {};
+    const CustomHeader = this.userConfig.omitTyp
+      ? OptionHeader
+      : { typ: SD_JWT_TYP, ...OptionHeader };
+    const header = { ...CustomHeader, alg };
     const jwt = new Jwt({
       header,
       payload: {

src/type.ts

@@ -3,7 +3,7 @@ import { Jwt } from './jwt';
 export const SD_SEPARATOR = '~';
 export const SD_LIST_KEY = '...';
 export const SD_DIGEST = '_sd';
-export const SD_JWT_TYP = 'sd+jwt';
+export const SD_JWT_TYP = 'sd-jwt';
 export const SD_DECOY = '_sd_decoy';
 export const KB_JWT_TYP = 'kb+jwt';