initial commit

2026-08-22 07:32:31 +02:00 · 2023-10-22 01:37:25 +05:30
parent 80327652c3
commit 97fd28697a
182 changed files with 55033 additions and 122 deletions
@@ -0,0 +1,48 @@
+import SignPdfError from './SignPdfError.js';
+
+const xrefToRefMap = (xrefString) => {
+    const lines = xrefString.split('\n').filter((l) => l !== '');
+
+    let index = 0;
+    let expectedLines = 0;
+    const xref = new Map();
+    lines.forEach((line) => {
+        const split = line.split(' ');
+        if (split.length === 2) {
+            index = parseInt(split[0]);
+            expectedLines = parseInt(split[1]);
+            return;
+        }
+        if (expectedLines <= 0) {
+            throw new SignPdfError(
+                'Too many lines in xref table.',
+                SignPdfError.TYPE_PARSE,
+            );
+        }
+        expectedLines -= 1;
+        const [offset, , inUse] = split;
+        if (inUse.trim() === 'f') {
+            index += 1;
+            return;
+        }
+        if (inUse.trim() !== 'n') {
+            throw new SignPdfError(
+                `Unknown in-use flag "${inUse}". Expected "n" or "f".`,
+                SignPdfError.TYPE_PARSE,
+            );
+        }
+        if (!/^\d+$/.test(offset.trim())) {
+            throw new SignPdfError(
+                `Expected integer offset. Got "${offset}".`,
+                SignPdfError.TYPE_PARSE,
+            );
+        }
+        const storeOffset = parseInt(offset.trim());
+        xref.set(index, storeOffset);
+        index += 1;
+    });
+
+    return xref;
+};
+
+export default xrefToRefMap;