Frida utility functions

util.js

module.exports = {
  hexStringToIntArray: function(str) {
    var res = []
    for(var i = 0; i < str.length; i += 2) {
      res.push(parseInt(str.substring(i, i+2), 16))
    }
    return res
  },

  byteArrayToHexString: function(array) {
    try {
      // Frida has two representations depending on how you get the array
      if ("fieldReturnType" in array) {
        array = array.value
      }
      else if (array.type != "byte") {
        console.log("Unexpected array type")
      }

      // The most straightforward way to get the array to a standard JS object
      array = JSON.parse(JSON.stringify(array))

      var res = "";
      for(var i = 0; i < array.length; i++){
          var hex = (array[i] & 255).toString(16)
          if(hex.length < 2) hex = "0" + hex
          res += hex
      }

      return res
    } catch(err) {
      console.log(String(err.stack))
      return ""
    }
  },
  
  inspectObject: function(obj) {
    const Class = Java.use("java.lang.Class")
    const tmp_obj = obj
    const fields = Java.cast(tmp_obj.getClass(), Class).getDeclaredFields()
    const methods = Java.cast(tmp_obj.getClass(), Class).getMethods()
    console.log("inspecting " + tmp_obj.getClass().toString())
    
    console.log("\tfields:")
    for (var i in fields) {
      console.log("\t\t" + fields[i].toString())
    }
    console.log("\tmethods:")
    for (var i in methods) {
      console.log("\t\t" + methods[i].toString())
    }
  },

  inspectJsObj: function(obj) {
    console.log(JSON.stringify(obj))
    for (var prop in obj) {
      const val = prop.startsWith("$") ? "" : obj[prop]

      if (obj.hasOwnProperty(prop)) {
        console.log("\tself." + prop + " : " + val)
      } else {
        console.log("\t" + prop + " : " + val)
      }
    }
  },
}