introduction of PresentationParserChain and PublicKeyResolverChain in…

…crease flexibility

src/services/interfaces.ts

@@ -6,6 +6,8 @@ import { SupportedCredentialProtocol } from "../lib/CredentialIssuerConfig/Suppo
 import { CredentialView } from "../authorization/types";
 import { AuthorizationServerState } from "../entities/AuthorizationServerState.entity";
 import { PresentationClaims, RelyingPartyState } from "../entities/RelyingPartyState.entity";
+import { PresentationParserChain } from "../vp_token/PresentationParserChain";
+import { PublicKeyResolverChain } from "../vp_token/PublicKeyResolverChain";
 
 export interface CredentialSigner {
 	sign(payload: any, headers?: any, disclosureFrame?: any): Promise<{ jws: string }>;
@@ -32,15 +34,17 @@ export interface OpenidForPresentationsReceivingInterface {
 
 	getSignedRequestObject(ctx: { req: Request, res: Response }): Promise<any>;
 	generateAuthorizationRequestURL(ctx: { req: Request, res: Response }, presentationDefinition: object, sessionId: string, callbackEndpoint?: string): Promise<{ url: URL; stateId: string }>;
-	getPresentationBySessionId(ctx: { req: Request, res: Response }): Promise<{ status: true, rpState: RelyingPartyState } | { status: false }>;
-	getPresentationById(id: string): Promise<{ status: boolean, presentationClaims?: PresentationClaims, rawPresentation?: string }>;
+	getPresentationBySessionId(sessionId: string): Promise<{ status: true, rpState: RelyingPartyState, presentations: unknown[] } | { status: false }>;
+	getPresentationById(id: string): Promise<{ status: boolean, presentationClaims?: PresentationClaims, presentations?: unknown[] }>;
 	responseHandler(ctx: { req: Request, res: Response }): Promise<void>;
 }
 
 
 export interface VerifierConfigurationInterface {
 	getConfiguration(): OpenidForPresentationsConfiguration;
 	getPresentationDefinitions(): any[];
+	getPresentationParserChain(): PresentationParserChain;
+	getPublicKeyResolverChain(): PublicKeyResolverChain;
 }
 
 
@@ -82,4 +86,4 @@ export interface CredentialDataModel {
 
 export interface CredentialDataModelRegistry extends CredentialDataModel {
 	register(dm: CredentialDataModel): void;
-}
+}

src/vp_token/IPresentationParser.ts

@@ -0,0 +1,4 @@
+
+export interface IPresentationParser {
+	parse(presentationRawFormat: string | object): Promise<{ credentialImage: string, credentialPayload: any } | { error: "PARSE_ERROR" }>;
+}

src/vp_token/IPublicKeyResolver.ts

@@ -0,0 +1,5 @@
+import { KeyLike } from "jose";
+
+export interface IPublicKeyResolver {
+	resolve(rawPresentation: string | object, format: string): Promise<{ publicKey: KeyLike, isTrusted: boolean } | { error: "UNABLE_TO_RESOLVE_PUBKEY" }>;
+}

src/vp_token/PresentationParserChain.ts

@@ -0,0 +1,25 @@
+import { IPresentationParser } from "./IPresentationParser";
+import { sdJwtDefaultParser } from "./sdJwtDefaultParser";
+
+export class PresentationParserChain {
+
+	constructor(private parserList: IPresentationParser[] = [
+		sdJwtDefaultParser
+	]) { }
+
+	addParser(p: IPresentationParser): this {
+		this.parserList.push(p);
+		return this;
+	}
+
+	async parse(rawPresentation: any): Promise<{ credentialImage: string, credentialPayload: any } | { error: "PARSE_ERROR" }> {
+		for (const p of this.parserList) {
+			const result = await p.parse(rawPresentation);
+			if ('error' in result) {
+				continue;
+			}
+			return { ...result };
+		}
+		return { error: "PARSE_ERROR" };
+	}
+}

src/vp_token/PublicKeyResolverChain.ts

@@ -0,0 +1,26 @@
+import { KeyLike } from "jose";
+import { IPublicKeyResolver } from "./IPublicKeyResolver";
+import { sdJwtPublicKeyResolverUsingX5CHeader } from "./sdJwtPublicKeyResolverUsingX5CHeader";
+
+export class PublicKeyResolverChain {
+
+	constructor(private resolverList: IPublicKeyResolver[] = [
+		sdJwtPublicKeyResolverUsingX5CHeader
+	]) { }
+
+	addResolver(p: IPublicKeyResolver): this {
+		this.resolverList.push(p);
+		return this;
+	}
+
+	async resolve(rawPresentation: any, format: string): Promise<{ publicKey: KeyLike, isTrusted: boolean } | { error: "UNABLE_TO_RESOLVE_PUBKEY" }> {
+		for (const p of this.resolverList) {
+			const result = await p.resolve(rawPresentation, format);
+			if ('error' in result) {
+				continue;
+			}
+			return { ...result };
+		}
+		return { error: "UNABLE_TO_RESOLVE_PUBKEY" };
+	}
+}

src/vp_token/sdJwtDefaultParser.ts

@@ -0,0 +1,87 @@
+import { config } from "../../config";
+import { generateDataUriFromSvg } from "../lib/generateDataUriFromSvg";
+import {
+	HasherAlgorithm,
+	HasherAndAlgorithm,
+	SdJwt,
+} from '@sd-jwt/core'
+
+import base64url from "base64url";
+import crypto from 'node:crypto';
+import axios from "axios";
+import { IPresentationParser } from "./IPresentationParser";
+
+
+// Encoding the string into a Uint8Array
+const hasherAndAlgorithm: HasherAndAlgorithm = {
+	hasher: (input: string) => {
+		// return crypto.subtle.digest('SHA-256', encoder.encode(input)).then((v) => new Uint8Array(v));
+		return new Promise((resolve, _reject) => {
+			const hash = crypto.createHash('sha256');
+			hash.update(input);
+			resolve(new Uint8Array(hash.digest()));
+		});
+	},
+	algorithm: HasherAlgorithm.Sha256
+}
+
+export const sdJwtDefaultParser: IPresentationParser = {
+	async parse(presentationRawFormat) {
+		if (typeof presentationRawFormat != 'string') {
+			return { error: "PARSE_ERROR" };
+		}
+
+		try {
+			let defaultLocale = 'en-US';
+			let credentialImage = null;
+			let credentialPayload = null;
+
+			if (presentationRawFormat.includes('~')) {
+				const parsedCredential = await SdJwt.fromCompact<Record<string, unknown>, any>(presentationRawFormat)
+					.withHasher(hasherAndAlgorithm)
+					.getPrettyClaims();
+				const sdJwtHeader = JSON.parse(base64url.decode(presentationRawFormat.split('.')[0])) as any;
+				credentialPayload = parsedCredential;
+				console.log("Parsed credential = ", parsedCredential)
+				const credentialIssuerMetadata = await axios.get(parsedCredential.iss + "/.well-known/openid-credential-issuer").catch(() => null);
+				let fistImageUri;
+				if (!credentialIssuerMetadata) {
+					console.error("Couldnt get image for the credential " + presentationRawFormat);
+				}
+				else {
+					console.log("Credential issuer metadata = ", credentialIssuerMetadata?.data)
+					fistImageUri = Object.values(credentialIssuerMetadata?.data?.credential_configurations_supported).map((conf: any) => {
+						if (conf?.vct == parsedCredential?.vct) {
+							return conf?.display && conf?.display[0] && conf?.display[0]?.background_image?.uri ? conf?.display[0]?.background_image?.uri : undefined;
+						}
+						return undefined;
+					}).filter((val) => val)[0];
+				}
+
+				if (sdJwtHeader?.vctm && sdJwtHeader?.vctm?.display?.length > 0 && sdJwtHeader?.vctm?.display[0][defaultLocale]?.rendering?.svg_templates.length > 0 && sdJwtHeader?.vctm?.display[0][defaultLocale]?.rendering?.svg_templates[0]?.uri) {
+					const response = await axios.get(sdJwtHeader?.vctm?.display[0][defaultLocale].rendering.svg_templates[0].uri);
+					const svgText = response.data;
+					const pathsWithValues: any[] = [];
+					const dataUri = generateDataUriFromSvg(svgText, pathsWithValues); // replaces all with empty string
+					credentialImage = dataUri;
+				}
+				else if (sdJwtHeader?.vctm && sdJwtHeader?.vctm?.display?.length > 0 && sdJwtHeader?.vctm?.display[0][defaultLocale]?.rendering?.simple?.logo?.uri) {
+					credentialImage = sdJwtHeader?.vctm?.display[0][defaultLocale]?.rendering?.simple?.logo?.uri;
+				}
+				else if (fistImageUri) {
+					credentialImage = fistImageUri;
+				}
+				else {
+					credentialImage = config.url + "/images/card.png";
+				}
+				return { credentialImage, credentialPayload };
+			}
+
+			return { error: "PARSE_ERROR" };
+		}
+		catch (err) {
+			console.error(err);
+			return { error: "PARSE_ERROR" };
+		}
+	},
+}

src/vp_token/sdJwtPublicKeyResolverUsingX5CHeader.ts

@@ -0,0 +1,40 @@
+import base64url from "base64url";
+import { VerifiableCredentialFormat } from "../types/oid4vci";
+import { IPublicKeyResolver } from "./IPublicKeyResolver";
+import { importX509, JWTHeaderParameters, KeyLike } from "jose";
+import { verifyCertificateChain } from "../util/verifyCertificateChain";
+import { config } from "../../config";
+
+export const sdJwtPublicKeyResolverUsingX5CHeader: IPublicKeyResolver = {
+	async resolve(rawPresentation: string | object, format: string): Promise<{ publicKey: KeyLike, isTrusted: boolean } | { error: "UNABLE_TO_RESOLVE_PUBKEY" }> {
+		if (format != VerifiableCredentialFormat.VC_SD_JWT || typeof rawPresentation != 'string') {
+			return { error: "UNABLE_TO_RESOLVE_PUBKEY" };
+		}
+
+		let isTrusted = false;
+		const [h, , ] = rawPresentation.split('.');
+		const header = JSON.parse(base64url.decode(h)) as JWTHeaderParameters;
+		if (header['x5c'] && header['x5c'] instanceof Array && header['x5c'][0]) {
+			const pemCerts = header['x5c'].map(cert => {
+				const pemCert = `-----BEGIN CERTIFICATE-----\n${cert}\n-----END CERTIFICATE-----`;
+				return pemCert;
+			});
+
+			// check if at least one root certificate verifies this credential
+			const result: boolean[] = await Promise.all(config.trustedRootCertificates.map(async (rootCert: string) => {
+				return verifyCertificateChain(rootCert, pemCerts);
+			}));
+
+
+			if (config.trustedRootCertificates.length != 0 && !result.includes(true)) {
+				console.log("Chain is not trusted");
+				isTrusted = false;
+			}
+			isTrusted = true;
+			console.info("Chain is trusted");
+			const cert = await importX509(pemCerts[0], header['alg'] as string);
+			return { isTrusted: isTrusted, publicKey: cert };
+		}
+		return { error: "UNABLE_TO_RESOLVE_PUBKEY" };
+	}
+}