MacOS Catalina: Slow by Design?

It seems like there is a lot of confusion here as to whether this is real or not. I've been able to confirm the behavior in the post by:

- Using a new, random executable. Even echo $rand_int will work. Edit: What I mean here is generate your rand int beforehand and statically include it in your script.

- Using a fresh filename too. Just throw a rand int at the end there. e.g. /tmp/test4329.sh

I MITMd myself while recording the network traffic and, sure enough, there is a request to ocsp.apple.com with a hash in the URL path and a bunch of binary data in the response body. Unsure what it is yet but the URL suggests it is generating a cert for the binary and checking it. See: https://en.wikipedia.org/wiki/Online_Certificate_Status_Prot...

Here's the URL I saw:

http://ocsp.apple.com/ocsp-devid01/ME4wTKADAgEAMEUwQzBBMAkGB...

Edit2: Anyone know what this hash format is? It's not quite base64, nor is it multiple base64 strings separated with '+'s but it seems similar...

Edit3: Here is the exact filename and file I used: https://gist.github.com/UsmannK/abb4b239c98ee45bdfcc5b284bf0...

Edit4 (final one probably...): On subsequent attempts I'm only seeing a request to https://api.apple-cloudkit.com and not the OCSP one anymore. Curiously, there's no headers at all. It is just checking for connectivity.

Here's some shell script to use a random file name and have friendlier output.

  RAND_FILE="/tmp/test-$RANDOM.sh";
  time_helper() { /usr/bin/time $RAND_FILE 2>&1 | tail -1 | awk '{print $1}'; }  # this just returns the real run time
  echo $'#!/bin/sh\necho Hello' $RANDOM > $RAND_FILE && chmod a+x  $RAND_FILE;
  echo "Testing $RAND_FILE";
  echo "execution time #1: $(time_helper) seconds";
  echo "execution time #2: $(time_helper) seconds";

Introducing a network delay makes the effect much more obvious. Normally I see a delay of about 0.1 seconds, but after using the XCode network link conditioner (pf rules) to add 500ms latency to everything the delay shoots way up to ~2 seconds.

example output:

  Testing /tmp/test-24411.sh
  execution time #1: 2.32 seconds
  execution time #2: 0.00 seconds

with developer tools checked both executions report "0.0 seconds".

Huh this is crazy. 2 seconds is way slow and this shouldn't involve any network activity. Seems like a real problem.

He/she added an artificial network latency/delay into the config, just like they describe. That is the reason for the delay. It is made artificially long on purpose.