refactor: rollback SHA-256 with CRC32 for hash generation

Author: andrii-harbour

eslint.config.mjs

@@ -56,7 +56,6 @@ export default [
         clearInterval: 'readonly',
 
         // Browser APIs (client-side code)
-        crypto: 'readonly',
         window: 'readonly',
         document: 'readonly',
         navigator: 'readonly',
@@ -69,7 +68,6 @@ export default [
         requestAnimationFrame: 'readonly',
         URLSearchParams: 'readonly',
         TextDecoder: 'readonly',
-        TextEncoder: 'readonly',
         FileReader: 'readonly',
         DOMRect: 'readonly',
 

packages/super-editor/src/core/super-converter/SuperConverter.js

@@ -1,5 +1,6 @@
 import * as xmljs from 'xml-js';
 import { v4 as uuidv4 } from 'uuid';
+import crc32 from 'buffer-crc32';
 import { DocxExporter, exportSchemaToJson } from './exporter';
 import { createDocumentJson, addDefaultStylesIfMissing } from './v2/importer/docxImporter.js';
 import { deobfuscateFont, getArrayBufferFromUrl } from './helpers.js';
@@ -68,33 +69,6 @@ const collectRunDefaultProperties = (
   }
 };
 
-/**
- * SHA-256 hash helpers using the Web Crypto API.
- * Works in all modern browsers and Node.js 20+.
- */
-async function sha256Hex(bytes) {
-  const hash = await crypto.subtle.digest('SHA-256', bytes);
-  return Array.from(new Uint8Array(hash))
-    .map((b) => b.toString(16).padStart(2, '0'))
-    .join('')
-    .toUpperCase();
-}
-
-async function hashString(str) {
-  return sha256Hex(new TextEncoder().encode(str));
-}
-
-async function hashFile(fileSource) {
-  if (fileSource instanceof ArrayBuffer) {
-    return sha256Hex(fileSource);
-  } else if (fileSource instanceof Blob || fileSource instanceof File) {
-    return sha256Hex(await fileSource.arrayBuffer());
-  } else if (fileSource instanceof Uint8Array) {
-    return sha256Hex(fileSource);
-  }
-  return null;
-}
-
 class SuperConverter {
   static allowedElements = Object.freeze({
     'w:document': 'doc',
@@ -778,32 +752,44 @@ class SuperConverter {
 
   /**
    * Generate identifier hash from documentGuid and dcterms:created
-   * Uses SHA-256 of the combined string for a compact identifier
+   * Uses CRC32 of the combined string for a compact identifier
    * Only call when both documentGuid and timestamp exist
    * @returns {string} Hash identifier in format "HASH-XXXXXXXX"
    */
-  async #generateIdentifierHash() {
+  #generateIdentifierHash() {
     const combined = `${this.documentGuid}|${this.getDocumentCreatedTimestamp()}`;
-    const hash = await hashString(combined);
-    return `HASH-${hash.substring(0, 8)}`;
+    const buffer = Buffer.from(combined, 'utf8');
+    const hash = crc32(buffer);
+    return `HASH-${hash.toString('hex').toUpperCase()}`;
   }
 
   /**
    * Generate content hash from file bytes
-   * Uses SHA-256 of the raw file content for a stable identifier
+   * Uses CRC32 of the raw file content for a stable identifier
    * @returns {Promise<string>} Hash identifier in format "HASH-XXXXXXXX"
    */
   async #generateContentHash() {
     if (!this.fileSource) {
+      // No file source available, generate a random hash (last resort)
       return `HASH-${uuidv4().replace(/-/g, '').substring(0, 8).toUpperCase()}`;
     }
 
     try {
-      const hash = await hashFile(this.fileSource);
-      if (!hash) {
+      let buffer;
+
+      if (Buffer.isBuffer(this.fileSource)) {
+        buffer = this.fileSource;
+      } else if (this.fileSource instanceof ArrayBuffer) {
+        buffer = Buffer.from(this.fileSource);
+      } else if (this.fileSource instanceof Blob || this.fileSource instanceof File) {
+        const arrayBuffer = await this.fileSource.arrayBuffer();
+        buffer = Buffer.from(arrayBuffer);
+      } else {
         return `HASH-${uuidv4().replace(/-/g, '').substring(0, 8).toUpperCase()}`;
       }
-      return `HASH-${hash.substring(0, 8)}`;
+
+      const hash = crc32(buffer);
+      return `HASH-${hash.toString('hex').toUpperCase()}`;
     } catch (e) {
       console.warn('[super-converter] Could not generate content hash:', e);
       return `HASH-${uuidv4().replace(/-/g, '').substring(0, 8).toUpperCase()}`;
@@ -835,7 +821,7 @@ class SuperConverter {
 
     if (hasGuid && hasTimestamp) {
       // Both exist: use identifierHash
-      this.documentUniqueIdentifier = await this.#generateIdentifierHash();
+      this.documentUniqueIdentifier = this.#generateIdentifierHash();
     } else {
       // Missing one or both: use contentHash for stability (same file = same hash)
       // But generate missing metadata so re-exported file will have complete metadata