Description:
------------
While setting up TLS for the DB in a development environment, I've found out that handshake issues during cURL requests using URIs with a self-signed certificate were affecting completely valid encrypted MySQL connections using both MySQLi and PDO MySQL.

I observed this because it was only happening on certain endpoints because they send this HTTP request to another service.

It's quite an edge-case (and low priority IMHO). However, it got me crazy since the error messages are all about the DB connection.

My idea was to create a better way to test this, but couldn't find any good example for TLS+MySQLnd (via PDO or MySQLi)...

Test script:
---------------
$conn = new PDO(
    'mysql:host=my-mysql-server;charset=utf8mb4',
    'root',
    'password',
    [
        PDO::MYSQL_ATTR_SSL_CA => '/local-tls-certificates/ca.pem',
        PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT => true,
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    ]
);

var_dump($conn->query('SELECT 1')->fetchAll(PDO::FETCH_ASSOC));

$handle = curl_init('https://self-signed.badssl.com/');
curl_setopt_array(
    $handle,
    [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_SSL_VERIFYPEER => true,
    ]
);

var_dump(curl_exec($handle));
curl_close($handle);

var_dump($conn->query('SELECT 1')->fetchAll(PDO::FETCH_ASSOC));

Expected result:
----------------
array(1) {
  [0]=>
  array(1) {
    [1]=>
    string(1) "1"
  }
}
bool(false)
array(1) {
  [0]=>
  array(1) {
    [1]=>
    string(1) "1"
  }
}

Actual result:
--------------
array(1) {
  [0]=>
  array(1) {
    [1]=>
    string(1) "1"
  }
}
bool(false)
[01-Nov-2019 17:03:02 UTC] PHP Warning:  PDO::query(): SSL operation failed with code 1. OpenSSL Error messages:
error:140E0197:SSL routines:SSL_shutdown:shutdown while in init in /app/aa.php on line 32

Warning: PDO::query(): SSL operation failed with code 1. OpenSSL Error messages:
error:140E0197:SSL routines:SSL_shutdown:shutdown while in init in /app/aa.php on line 32
[01-Nov-2019 17:03:02 UTC] PHP Warning:  PDO::query(): MySQL server has gone away in /app/aa.php on line 32

Warning: PDO::query(): MySQL server has gone away in /app/aa.php on line 32
[01-Nov-2019 17:03:02 UTC] PHP Warning:  PDO::query(): Error reading result set's header in /app/aa.php on line 32

Warning: PDO::query(): Error reading result set's header in /app/aa.php on line 32
[01-Nov-2019 17:03:02 UTC] PHP Fatal error:  Uncaught PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away in /app/aa.php:32
Stack trace:
#0 /app/aa.php(32): PDO->query('SELECT 1')
#1 {main}
  thrown in /app/aa.php on line 32

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away in /app/aa.php:32
Stack trace:
#0 /app/aa.php(32): PDO->query('SELECT 1')
#1 {main}
  thrown in /app/aa.php on line 32