Patching ASR

This guide is out of date. Please don't use this, use bundlegen instead for now.

When you first open IDA, you'll see this window. Click on New, then navigate to your ASR binary.
After you've selected the ASR binary, you'll get to this window. Don't change anything, just click on Ok at the bottom.
Wait for IDA to finish autoanalysis on the ASR binary. It'll be finished when the bottom left corner of the window says AU: idle.

Bring up the text search window.
Type Image failed into the text box, then click Ok.
Right click and click Text View.
You should see something similar to this. Write down the highlighted values somewhere.
- For the rest of the guide, I'll be referring to the green highlighted text as failed_loc, and the purple-bluish highlighted text as failed_loc_addr.

Open the text search window again, and search for Image passed.
You should see something similar to this. Write down the highlighted values somewhere.
- For the rest of the guide, I'll be referring to the pink highlighted text as passed_loc, and the orange highlighted text as passed_loc_addr.

Search for failed_loc, but make sure to check Find all occurrences before searching.
You'll be taken to a view of all occurrences of failed_loc. We'll only be patching the first occurrence, so double click on the first result.
You should see something similar to this. Write down the highlighted value somewhere.
- For the rest of the guide, I'll be referring to the yellow highlighted text as failed_ref_addr, and the gray highlighted text as failed_ref.

Highlight failed_ref and switch to the Hex View. This will show you the failed_ref instruction in hex. Write this down somewhere.
- For the rest of the guide, I'll be referring to it as failed_ref_hex.

Go to this hex calculator. Change the operation to subtraction, and enter in passed_loc_addr and failed_ref_addr for the first and second values, respectively. Calculate the result, and write down the hex result somewhere.
- For the rest of the guide, I'll be referring to it as addr_result.

Go to armconverter, and click on the icon with 2 arrows to switch to hex -> arm.
On the left, paste failed_ref_hex. On the right, highlight and copy the value under ARM64.
Click on the icon with 2 arrows again to switch back to arm -> hex. Paste in the value you got from under ARM64.
Change the last value (that ends in 0x) to 0xaddr_result.
- (e.g. If your addr_result was 6, change the last value to 0x6)

Write down the value under ARM64.
- For the rest of the guide, I'll be referring to it as hex_result.
Go back to IDA. Under the Hex View, click on failed_ref_hex (make sure the text cursor is at the beginning of failed_ref_hex), then right click and select Edit.... Type in hex_result, then right click and select Apply changes.
At the top, click on Edit -> Patch Program -> Apply patches to input file...
You're finished!
Before:
After:
Don't forget to resign the binary with ldid, or else it won't be usable.
- ldid -e asr > entitlements.xml
- ldid -Sentitlements.xml <patched ASR binary>
- rm entitlements.xml