composer: The "https://packagist.org/packages.json" file could not be downloaded: failed to open stream: No connection could be made because the target machine actively refused it.

My composer.json:

{
    "name": "ricadiz/composer",
    "require": {}
}

Output of composer diagnose:

Checking platform settings: OK
Checking git settings: OK
Checking http connectivity to packagist: WARNING
[Composer\Downloader\TransportException] The "http://packagist.org/packages.json" file could not be downloaded: failed to open stream: No connection could be made because the target machine actively refused it.

Checking https connectivity to packagist: WARNING
[Composer\Downloader\TransportException] The "https://packagist.org/packages.json" file could not be downloaded: failed to open stream: No connection could be made because the target machine actively refused it.

Checking github.com rate limit: OK
Checking disk free space: OK
Checking pubkeys:
Tags Public Key Fingerprint: 57815BA2 7E54DC31 7ECC7CC5 573090D0  87719BA6 8F3BB723 4E5D42D0 84A14642
Dev Public Key Fingerprint: 4AC45767 E5EC2265 2F0C1167 CBBB8A2B  0C708369 153E328C AD90147D AFE50952
OK
Checking composer version: OK
Composer version: 1.6.5
PHP version: 7.2.7
PHP binary path: D:\xampp7\php\php.exe

When I run this command:

composer create-project --prefer-dist laravel/laravel testapp

I get the following output:

  [Composer\Downloader\TransportException]                                      
  The "https://packagist.org/packages.json" file could not be downloaded: failed to open stream: No connection could
  be made because the target machine actively refused it.         

Basically I was trying to setup composer in a corporate environment to enable to work with Laravel projects. I freshly installed latest XAMPP. But I have already spent days looking for solution on how to make composer work. I have already tried the following:

• Disable IPv6 wireless connection (Since I’m currently using laptop)
• Set/Remove environment variables (tried http_proxy alone, http_proxy, https_proxy, HTTP_PROXY, HTTP_PROXY, all four of them) but still would fail somehow
• Did restart every set of env variables
• Removed all the environment proxy variable and manually doing export HTTP_PROXY=.... and export HTTPS_PROXY=...
• Yes, I use credentials in my proxy username:password@host:port

Additional notes:

• I used the windows installer to install composer, and I noticed that the installer doesn’t accept leading http:// or https:// in the proxy field during installation. Which I also spent days troubleshooting how to install composer. I’m not using VM for now.
• I installed latest cURL and tried the following command: curl https://packagist.org/package.json -vv And somehow got the json from the respose:

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1456  100  1456    0     0   3586      0 --:--:-- --:--:-- --:--:--  3586{"packages":[],"notify":"https://packagist.org/downloads/%package%","notify-batch":"https://packagist.org/downloads/","providers-url":"/p/%package%$%hash%.json","search":"https://packagist.org/search.json?q=%query%&type=%type%","provider-includes":{"p/provider-2013$%hash%.json":{"sha256":"99bae025d4d2e751a27fe35e136f601de188eda7077be4d5f63a549ea97907db"},"p/provider-2014$%hash%.json":{"sha256":"9406108133abe969d70795f837a3a9f72b416d25ca63944d1fc43355fde3cacf"},"p/provider-2015$%hash%.json":{"sha256":"9e6c81496931a07012024abf1cf1c114e8b86188f643d9a6f5481dbda26d02cd"},"p/provider-2016$%hash%.json":{"sha256":"7a798e4cb4e4191c3932f06c5d6cf099b1397df3d8eee73f61f73ca8f6dbe917"},"p/provider-2017$%hash%.json":{"sha256":"31a86e95e9ba4cae26868d352250c93c2c20f8ff6f454cf7086ba066c1877e3c"},"p/provider-2017-10$%hash%.json":{"sha256":"b2da560198469600563d4428b4c7c769601802154d16b224cb559404567cad72"},"p/provider-2018-01$%hash%.json":{"sha256":"b1959d2e442d85a41d6c5fda0dca0946a342f2da07df60eae618a2ed19421a0d"},"p/provider-2018-04$%hash%.json":{"sha256":"4b39c9ca91e2bba7265b8b1f85bdb8dc522a5c8df00b322adfb43ac3c1d5c4a2"},"p/provider-2018-07$%hash%.json":{"sha256":"93936039e8fd151b21c68a396a7a1217e2d725803a2b54b0e1cad961c76aabfc"},"p/provider-archived$%hash%.json":{"sha256":"939a942590ec7e93239cd4beb63399da3206d5337563e0ac345a5b58f458b46e"},"p/provider-latest$%hash%.json":{"sha256":"793c519d05e378606154e744a199e151f88adb32f526294cd15c78895af3a3a8"}}}

• We’re using a domain user account so basically my proxy authentication looks like this: domain/username:password
• I can access the url using a web browser
• I got certificate errors for https://getcomposer.org also along the way but I already managed to fix it by importing the necessary intermediate ca.
• I tried to check run this command openssl s_client -connect packagist.org:443 and got this response:

connect: No error
connect:errno=0

I would like to be much in detail but I don’t want this post to get long. Thanks.