Fix signature detection for QPDF-367-0.pdf

We added QPDF-367-0.pdf as a regression test, but it also contains
a different type of signature we don't currently support.

Since we already have it in tree extend the regex to also detect it.

src/utils.js

@@ -132,7 +132,7 @@ export const readArrayBufferFileContent = async (file) => {
  */
 export const getPDFSignatureCount = async (file) => {
     const sigRegex = new RegExp(
-        '/Type\\s*/Sig[\\s\\S]*?/SubFilter\\s*(/ETSI\\.CAdES\\.detached|/adbe\\.pkcs7\\.detached)',
+        '(/Type\\s*/Sig|/Filter\\s*/Adobe.PPKLite)[\\s\\S]*?/SubFilter\\s*(/ETSI\\.CAdES\\.detached|/adbe\\.pkcs7\\.detached)',
         'g'
     );
     const content = await readBinaryFileContent(file);

test/unit.js

@@ -76,7 +76,7 @@ suite('pdf signature detection', () => {
             return getPDFFile(await resp.arrayBuffer());
         }
 
-        assert.equal((await getPDFSignatureCount(await getRealPDFFile('QPDF-367-0.pdf'))), 0);
+        assert.equal((await getPDFSignatureCount(await getRealPDFFile('QPDF-367-0.pdf'))), 1);
         assert.equal((await getPDFSignatureCount(await getRealPDFFile('qual-sig-simple.pdf'))), 1);
         assert.equal((await getPDFSignatureCount(await getRealPDFFile('qual-sig-tugraz-multiple.pdf'))), 2);
     });