iOS Reverse analysis Note--replay Reverse analysis

normal find video or image processing file GL script is to find out the script loaded function Glshadersource broken down, last week in the analysis of replay, it was strange that Ida did not find glshadersource this function, So I search in the Disassembly window Glshadersource, found a lot of related functions to use it, so one by one try not to break down, think of image processing must call GL Script, so search GLSL find correlation function or not a can break down, So all the functions that opened the file are still not broken

so dazed, tried a lot of methods, search for video-related functions, find the buffer sample function to capture the output Didoutputsamplebuffer, the video processing will be used to its results are still not broken, and find the image synthesis processing function or not, video output, compile, file read, image synthesis, It can't be broken, I wonder if this file is a GL script called by Python and then compiled in its own engine we can't break it.

In the absence of a breakthrough, I went to the app inside the file directory search, found a large number of GLSL script, in order to test the script function I delete all the script and then add a view function, find all the script function, is happy when the boss said only pixel coloring script, another script should be hidden inside, In the absence of a way to occasionally try someone else said not often break the method directly in the GDB inside the broken function, do not hope to try incredibly to break down, Ida can not find out the GDB actually found out, and then the script will all print out

Summary: Can not too believe an authoritative tool, also can not abandon a not be optimistic method, adverse choice too many no so-called good or bad, ruler has long, inch has short