feat: new helper functions to replace regexes #807

Implemented new StringUtil helper functions: splitCommaSeparated, sanitizeUrlPart, isValidFileName.
Added helper functions to HeaderUtil: matchesAuthorizationScheme, hasScheme.
Added unit tests for the new helper functions.
Refactored codebase to use helper functions instead of regexes if applicable.

src/authentication/BearerWebIdExtractor.ts

@@ -4,6 +4,7 @@ import { getLoggerFor } from '../logging/LogUtil';
 import type { HttpRequest } from '../server/HttpRequest';
 import { BadRequestHttpError } from '../util/errors/BadRequestHttpError';
 import { NotImplementedHttpError } from '../util/errors/NotImplementedHttpError';
+import { matchesAuthorizationScheme } from '../util/HeaderUtil';
 import { CredentialGroup } from './Credentials';
 import type { CredentialSet } from './Credentials';
 import { CredentialsExtractor } from './CredentialsExtractor';
@@ -19,7 +20,7 @@ export class BearerWebIdExtractor extends CredentialsExtractor {
 
   public async canHandle({ headers }: HttpRequest): Promise<void> {
     const { authorization } = headers;
-    if (!authorization || !/^Bearer /ui.test(authorization)) {
+    if (!matchesAuthorizationScheme('Bearer', authorization)) {
       throw new NotImplementedHttpError('No Bearer Authorization header specified.');
     }
   }

src/authentication/DPoPWebIdExtractor.ts

@@ -5,6 +5,7 @@ import { getLoggerFor } from '../logging/LogUtil';
 import type { HttpRequest } from '../server/HttpRequest';
 import { BadRequestHttpError } from '../util/errors/BadRequestHttpError';
 import { NotImplementedHttpError } from '../util/errors/NotImplementedHttpError';
+import { matchesAuthorizationScheme } from '../util/HeaderUtil';
 import { CredentialGroup } from './Credentials';
 import type { CredentialSet } from './Credentials';
 import { CredentialsExtractor } from './CredentialsExtractor';
@@ -27,7 +28,7 @@ export class DPoPWebIdExtractor extends CredentialsExtractor {
 
   public async canHandle({ headers }: HttpRequest): Promise<void> {
     const { authorization } = headers;
-    if (!authorization || !/^DPoP /ui.test(authorization)) {
+    if (!matchesAuthorizationScheme('DPoP', authorization)) {
       throw new NotImplementedHttpError('No DPoP-bound Authorization header specified.');
     }
   }

src/authentication/UnsecureWebIdExtractor.ts

@@ -1,6 +1,7 @@
 import { getLoggerFor } from '../logging/LogUtil';
 import type { HttpRequest } from '../server/HttpRequest';
 import { NotImplementedHttpError } from '../util/errors/NotImplementedHttpError';
+import { matchesAuthorizationScheme } from '../util/HeaderUtil';
 import { CredentialGroup } from './Credentials';
 import type { CredentialSet } from './Credentials';
 import { CredentialsExtractor } from './CredentialsExtractor';
@@ -13,7 +14,7 @@ export class UnsecureWebIdExtractor extends CredentialsExtractor {
 
   public async canHandle({ headers }: HttpRequest): Promise<void> {
     const { authorization } = headers;
-    if (!authorization || !/^WebID /ui.test(authorization)) {
+    if (!matchesAuthorizationScheme('WebID', authorization)) {
       throw new NotImplementedHttpError('No WebID Authorization header specified.');
     }
   }

src/http/UnsecureWebSocketsProtocol.ts

@@ -4,6 +4,7 @@ import { getLoggerFor } from '../logging/LogUtil';
 import type { HttpRequest } from '../server/HttpRequest';
 import { WebSocketHandler } from '../server/WebSocketHandler';
 import { parseForwarded } from '../util/HeaderUtil';
+import { splitCommaSeparated } from '../util/StringUtil';
 import type { ResourceIdentifier } from './representation/ResourceIdentifier';
 
 const VERSION = 'solid-0.1';
@@ -36,7 +37,7 @@ class WebSocketListener extends EventEmitter {
     if (!protocolHeader) {
       this.sendMessage('warning', `Missing Sec-WebSocket-Protocol header, expected value '${VERSION}'`);
     } else {
-      const supportedProtocols = protocolHeader.split(/\s*,\s*/u);
+      const supportedProtocols = splitCommaSeparated(protocolHeader);
       if (!supportedProtocols.includes(VERSION)) {
         this.sendMessage('error', `Client does not support protocol ${VERSION}`);
         this.stop();

src/http/input/conditions/BasicConditionsParser.ts

@@ -3,6 +3,7 @@ import type { HttpRequest } from '../../../server/HttpRequest';
 import type { BasicConditionsOptions } from '../../../storage/BasicConditions';
 import { BasicConditions } from '../../../storage/BasicConditions';
 import type { Conditions } from '../../../storage/Conditions';
+import { splitCommaSeparated } from '../../../util/StringUtil';
 import { ConditionsParser } from './ConditionsParser';
 
 /**
@@ -58,6 +59,9 @@ export class BasicConditionsParser extends ConditionsParser {
    * Undefined if there is no value for the given header name.
    */
   private parseTagHeader(request: HttpRequest, header: 'if-match' | 'if-none-match'): string[] | undefined {
-    return request.headers[header]?.trim().split(/\s*,\s*/u);
+    const headerValue = request.headers[header];
+    if (headerValue) {
+      return splitCommaSeparated(headerValue.trim());
+    }
   }
 }

src/identity/interaction/email-password/util/RegistrationManager.ts

@@ -4,6 +4,7 @@ import { getLoggerFor } from '../../../../logging/LogUtil';
 import type { IdentifierGenerator } from '../../../../pods/generate/IdentifierGenerator';
 import type { PodManager } from '../../../../pods/PodManager';
 import type { PodSettings } from '../../../../pods/settings/PodSettings';
+import { hasScheme } from '../../../../util/HeaderUtil';
 import { joinUrl } from '../../../../util/PathUtil';
 import type { OwnershipValidator } from '../../../ownership/OwnershipValidator';
 import { assertPassword } from '../EmailPasswordUtil';
@@ -139,7 +140,7 @@ export class RegistrationManager {
     // Parse WebID
     if (!validated.createWebId) {
       const trimmedWebId = this.trimString(webId);
-      assert(trimmedWebId && /^https?:\/\/[^/]+/u.test(trimmedWebId), 'Please enter a valid WebID.');
+      assert(trimmedWebId && hasScheme(trimmedWebId, 'http', 'https'), 'Please enter a valid WebID.');
       validated.webId = trimmedWebId;
     }
 

src/identity/storage/WebIdAdapterFactory.ts

@@ -6,6 +6,7 @@ import { getLoggerFor } from '../../logging/LogUtil';
 import type { RepresentationConverter } from '../../storage/conversion/RepresentationConverter';
 import { createErrorMessage } from '../../util/errors/ErrorUtil';
 import { responseToDataset } from '../../util/FetchUtil';
+import { hasScheme } from '../../util/HeaderUtil';
 import { OIDC } from '../../util/Vocabularies';
 import type { AdapterFactory } from './AdapterFactory';
 
@@ -42,7 +43,7 @@ export class WebIdAdapter implements Adapter {
     // Try to see if valid client metadata is found at the given Client ID.
     // The oidc-provider library will check if the redirect_uri matches an entry in the list of redirect_uris,
     // so no extra checks are needed from our side.
-    if (!payload && this.name === 'Client' && /^https?:\/\/.+/u.test(id)) {
+    if (!payload && this.name === 'Client' && hasScheme(id, 'http', 'https')) {
       this.logger.debug(`Looking for payload data at ${id}`);
       // All checks based on https://solid.github.io/authentication-panel/solid-oidc/#clientids-webid
       if (!/^https:|^http:\/\/localhost(?::\d+)?(?:\/|$)/u.test(id)) {

src/index.ts

@@ -433,6 +433,7 @@ export * from './util/QuadUtil';
 export * from './util/RecordObject';
 export * from './util/ResourceUtil';
 export * from './util/StreamUtil';
+export * from './util/StringUtil';
 export * from './util/TermUtil';
 export * from './util/TimerUtil';
 export * from './util/Vocabularies';

src/pods/generate/SubdomainIdentifierGenerator.ts

@@ -1,5 +1,6 @@
 import type { ResourceIdentifier } from '../../http/representation/ResourceIdentifier';
 import { ensureTrailingSlash, extractScheme } from '../../util/PathUtil';
+import { sanitizeUrlPart } from '../../util/StringUtil';
 import type { IdentifierGenerator } from './IdentifierGenerator';
 
 /**
@@ -15,7 +16,7 @@ export class SubdomainIdentifierGenerator implements IdentifierGenerator {
 
   public generate(name: string): ResourceIdentifier {
     // Using the punycode converter is a risk as it doesn't convert slashes for example
-    const cleanName = name.replace(/\W/gu, '-');
+    const cleanName = sanitizeUrlPart(name);
     return { path: `${this.baseParts.scheme}${cleanName}.${this.baseParts.rest}` };
   }
 }

src/pods/generate/SuffixIdentifierGenerator.ts

@@ -1,5 +1,6 @@
 import type { ResourceIdentifier } from '../../http/representation/ResourceIdentifier';
 import { ensureTrailingSlash } from '../../util/PathUtil';
+import { sanitizeUrlPart } from '../../util/StringUtil';
 import type { IdentifierGenerator } from './IdentifierGenerator';
 
 /**
@@ -14,7 +15,7 @@ export class SuffixIdentifierGenerator implements IdentifierGenerator {
   }
 
   public generate(name: string): ResourceIdentifier {
-    const cleanName = name.replace(/\W/gu, '-');
+    const cleanName = sanitizeUrlPart(name);
     return { path: ensureTrailingSlash(new URL(cleanName, this.base).href) };
   }
 }

src/server/middleware/WebSocketAdvertiser.ts

@@ -1,4 +1,4 @@
-import { addHeader } from '../../util/HeaderUtil';
+import { addHeader, hasScheme } from '../../util/HeaderUtil';
 import { HttpHandler } from '../HttpHandler';
 import type { HttpResponse } from '../HttpResponse';
 
@@ -11,7 +11,7 @@ export class WebSocketAdvertiser extends HttpHandler {
   public constructor(baseUrl: string) {
     super();
     const socketUrl = new URL(baseUrl);
-    socketUrl.protocol = /^(?:http|ws):/u.test(baseUrl) ? 'ws:' : 'wss:';
+    socketUrl.protocol = hasScheme(baseUrl, 'http', 'ws') ? 'ws:' : 'wss:';
     this.socketUrl = socketUrl.href;
   }
 

src/storage/IndexRepresentationStore.ts

@@ -4,6 +4,7 @@ import type { RepresentationPreferences } from '../http/representation/Represent
 import type { ResourceIdentifier } from '../http/representation/ResourceIdentifier';
 import { NotFoundHttpError } from '../util/errors/NotFoundHttpError';
 import { isContainerIdentifier } from '../util/PathUtil';
+import { isValidFileName } from '../util/StringUtil';
 import type { Conditions } from './Conditions';
 import { cleanPreferences, matchesMediaType } from './conversion/ConversionUtil';
 import { PassthroughStore } from './PassthroughStore';
@@ -31,7 +32,7 @@ export class IndexRepresentationStore extends PassthroughStore {
 
   public constructor(source: ResourceStore, indexName = 'index.html', mediaRange = 'text/html') {
     super(source);
-    assert(/^[\w.-]+$/u.test(indexName), 'Invalid index name');
+    assert(isValidFileName(indexName), 'Invalid index name');
     this.indexName = indexName;
     this.mediaRange = mediaRange;
   }

src/storage/conversion/ErrorToTemplateConverter.ts

@@ -5,6 +5,7 @@ import { INTERNAL_ERROR } from '../../util/ContentTypes';
 import { HttpError } from '../../util/errors/HttpError';
 import { resolveModulePath } from '../../util/PathUtil';
 import { getSingleItem } from '../../util/StreamUtil';
+import { isValidFileName } from '../../util/StringUtil';
 import type { TemplateEngine } from '../../util/templates/TemplateEngine';
 import { BaseTypedRepresentationConverter } from './BaseTypedRepresentationConverter';
 import type { RepresentationConverterArgs } from './RepresentationConverter';
@@ -63,7 +64,7 @@ export class ErrorToTemplateConverter extends BaseTypedRepresentationConverter {
     if (HttpError.isInstance(error)) {
       try {
         const templateFile = `${error.errorCode}${this.extension}`;
-        assert(/^[\w.-]+$/u.test(templateFile), 'Invalid error template name');
+        assert(isValidFileName(templateFile), 'Invalid error template name');
         description = await this.templateEngine.render(error.details ?? {},
           { templateFile, templatePath: this.codeTemplatesPath });
       } catch {

src/util/HeaderUtil.ts

@@ -1,9 +1,12 @@
 import type { IncomingHttpHeaders } from 'http';
+import escapeStringRegexp from 'escape-string-regexp';
 import { getLoggerFor } from '../logging/LogUtil';
 import type { HttpResponse } from '../server/HttpResponse';
 import { BadRequestHttpError } from './errors/BadRequestHttpError';
 
 const logger = getLoggerFor('HeaderUtil');
+// Map used as a simple cache in the helper function matchesAuthorizationScheme.
+const authSchemeRegexCache: Map<string, RegExp> = new Map();
 
 // BNF based on https://tools.ietf.org/html/rfc7231
 //
@@ -508,6 +511,7 @@ export function parseForwarded(headers: IncomingHttpHeaders): Forwarded {
 
 /**
  * Parses the link header(s) and returns an array of LinkEntry objects.
+ *
  * @param link - A single link header or an array of link headers
  * @returns A LinkEntry array, LinkEntry contains a link and a params Record&lt;string,string&gt;
  */
@@ -547,3 +551,32 @@ export function parseLinkHeader(link: string | string[] = []): LinkEntry[] {
   }
   return links;
 }
+
+/**
+ * Checks if the value of an HTTP Authorization header matches a specific scheme (e.g. Basic, Bearer, etc).
+ *
+ * @param scheme - Name of the authorization scheme (case insensitive).
+ * @param authorization - The value of the Authorization header (may be undefined).
+ * @returns True if the Authorization header uses the specified scheme, false otherwise.
+ */
+export function matchesAuthorizationScheme(scheme: string, authorization?: string): boolean {
+  const lowerCaseScheme = scheme.toLowerCase();
+  if (!authSchemeRegexCache.has(lowerCaseScheme)) {
+    authSchemeRegexCache.set(lowerCaseScheme, new RegExp(`^${escapeStringRegexp(lowerCaseScheme)} `, 'ui'));
+  }
+  // Support authorization being undefined (for the sake of usability).
+  return typeof authorization !== 'undefined' && authSchemeRegexCache.get(lowerCaseScheme)!.test(authorization);
+}
+
+/**
+ * Checks if the scheme part of the specified url matches at least one of the provided options.
+ *
+ * @param url - A string representing the URL.
+ * @param schemes - Scheme value options (the function will check if at least one matches the URL scheme).
+ * @returns True if the URL scheme matches at least one of the provided options, false otherwise.
+ */
+export function hasScheme(url: string, ...schemes: string[]): boolean {
+  const schemeOptions = new Set(schemes.map((item): string => item.toLowerCase()));
+  const urlSchemeResult = /^(.+?):\/\//u.exec(url);
+  return urlSchemeResult ? schemeOptions.has(urlSchemeResult[1].toLowerCase()) : false;
+}

src/util/StringUtil.ts

@@ -0,0 +1,30 @@
+/**
+ * Splits a string by comma.
+ *
+ * @param input - String instance to split.
+ *
+ * @returns A String array containining the split parts.
+ */
+export function splitCommaSeparated(input: string): string[] {
+  return input.split(/\s*,\s*/u);
+}
+
+/**
+ * Sanitizes part of a URL by replacing non-word content with a '-'.
+ *
+ * @param urlPart - The URL part to sanitize.
+ * @returns The sanitized output.
+ */
+export function sanitizeUrlPart(urlPart: string): string {
+  return urlPart.replace(/\W/gu, '-');
+}
+
+/**
+ * Checks the validity of a file name. A valid name consists of word characters, '-' or '.'.
+ *
+ * @param name - The name of the file to validate.
+ * @returns True if the filename is valid, false otherwise.
+ */
+export function isValidFileName(name: string): boolean {
+  return /^[\w.-]+$/u.test(name);
+}

test/integration/Middleware.test.ts

@@ -3,6 +3,7 @@ import request from 'supertest';
 import type { BaseHttpServerFactory } from '../../src/server/BaseHttpServerFactory';
 import type { HttpHandlerInput } from '../../src/server/HttpHandler';
 import { HttpHandler } from '../../src/server/HttpHandler';
+import { splitCommaSeparated } from '../../src/util/StringUtil';
 import { getPort } from '../util/Util';
 import { getTestConfigPath, instantiateFromConfig } from './Config';
 
@@ -96,46 +97,46 @@ describe('An http server with middleware', (): void => {
   it('exposes the Accept-[Method] header via CORS.', async(): Promise<void> => {
     const res = await request(server).get('/').expect(200);
     const exposed = res.header['access-control-expose-headers'];
-    expect(exposed.split(/\s*,\s*/u)).toContain('Accept-Patch');
-    expect(exposed.split(/\s*,\s*/u)).toContain('Accept-Post');
-    expect(exposed.split(/\s*,\s*/u)).toContain('Accept-Put');
+    expect(splitCommaSeparated(exposed)).toContain('Accept-Patch');
+    expect(splitCommaSeparated(exposed)).toContain('Accept-Post');
+    expect(splitCommaSeparated(exposed)).toContain('Accept-Put');
   });
 
   it('exposes the Last-Modified and ETag headers via CORS.', async(): Promise<void> => {
     const res = await request(server).get('/').expect(200);
     const exposed = res.header['access-control-expose-headers'];
-    expect(exposed.split(/\s*,\s*/u)).toContain('ETag');
-    expect(exposed.split(/\s*,\s*/u)).toContain('Last-Modified');
+    expect(splitCommaSeparated(exposed)).toContain('ETag');
+    expect(splitCommaSeparated(exposed)).toContain('Last-Modified');
   });
 
   it('exposes the Link header via CORS.', async(): Promise<void> => {
     const res = await request(server).get('/').expect(200);
     const exposed = res.header['access-control-expose-headers'];
-    expect(exposed.split(/\s*,\s*/u)).toContain('Link');
+    expect(splitCommaSeparated(exposed)).toContain('Link');
   });
 
   it('exposes the Location header via CORS.', async(): Promise<void> => {
     const res = await request(server).get('/').expect(200);
     const exposed = res.header['access-control-expose-headers'];
-    expect(exposed.split(/\s*,\s*/u)).toContain('Location');
+    expect(splitCommaSeparated(exposed)).toContain('Location');
   });
 
   it('exposes the MS-Author-Via header via CORS.', async(): Promise<void> => {
     const res = await request(server).get('/').expect(200);
     const exposed = res.header['access-control-expose-headers'];
-    expect(exposed.split(/\s*,\s*/u)).toContain('MS-Author-Via');
+    expect(splitCommaSeparated(exposed)).toContain('MS-Author-Via');
   });
 
   it('exposes the WAC-Allow header via CORS.', async(): Promise<void> => {
     const res = await request(server).get('/').expect(200);
     const exposed = res.header['access-control-expose-headers'];
-    expect(exposed.split(/\s*,\s*/u)).toContain('WAC-Allow');
+    expect(splitCommaSeparated(exposed)).toContain('WAC-Allow');
   });
 
   it('exposes the Updates-Via header via CORS.', async(): Promise<void> => {
     const res = await request(server).get('/').expect(200);
     const exposed = res.header['access-control-expose-headers'];
-    expect(exposed.split(/\s*,\s*/u)).toContain('Updates-Via');
+    expect(splitCommaSeparated(exposed)).toContain('Updates-Via');
   });
 
   it('sends incoming requests to the handler.', async(): Promise<void> => {