Only resign macho files that can be processed by ldid2

Author: radare

lib/bin.js

@@ -6,19 +6,31 @@ const macho = require('macho');
 const fs = require('fs');
 
 const MACH0_MIN_SIZE = 1024 * 4;
+const MH_EXECUTE = 2;
+const MH_DYLIB = 6;
+const MH_BUNDLE = 8;
 
 function isMacho (data) {
   if (typeof data === 'string') {
     if (!fs.lstatSync(data).isFile()) {
       return false;
     }
     const fd = fs.openSync(data, 'r');
-    data = Buffer.alloc(4);
-    if (fs.readSync(fd, data, 0, 4) !== 4) {
+    data = Buffer.alloc(32);
+    if (fs.readSync(fd, data, 0, 32) !== 32) {
       return false;
     }
     fs.close(fd);
   }
+  const fileType = data[15];
+  switch (fileType) {
+    case MH_EXECUTE:
+    case MH_DYLIB:
+    case MH_BUNDLE:
+      break;
+    default:
+      return false;
+  }
   const magics = [
     [0xca, 0xfe, 0xba, 0xbe], // fat
     [0xce, 0xfa, 0xed, 0xfe], // 32bit