Fix PHP7.2 bug

Author: Spomky

.github/workflows/functional-tests.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['7.3', '7.4', '8.0']
+        php-versions: ['7.2', '7.3', '7.4', '8.0']
     name: PHP ${{ matrix.php-versions }} Test on ${{ matrix.operating-system }}
 
     steps:

.github/workflows/unit-tests.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ ubuntu-latest ]
-        php-versions: ['7.3', '7.4', '8.0']
+        php-versions: ['7.2', '7.3', '7.4', '8.0']
     name: PHP ${{ matrix.php-versions }} Test on ${{ matrix.operating-system }}
 
     steps:

phpstan.neon

@@ -18,6 +18,7 @@ parameters:
         - '#Array .* does not accept object\.#'
         - '#Invalid type object to throw\.#'
         - '#Strict comparison using === between .* and .* will always evaluate to false\.#'
+        - '#Binary operation "\^" between string and 1 results in an error\.#'
 includes:
     - vendor/phpstan/phpstan-strict-rules/rules.neon
     - vendor/phpstan/phpstan-phpunit/extension.neon

src/Ecc/Curve.php

@@ -15,7 +15,6 @@
 
 use Brick\Math\BigInteger;
 use function is_null;
-use function ord;
 use RuntimeException;
 
 /**
@@ -202,7 +201,7 @@ public function mul(Point $one, BigInteger $n): Point
         $n1 = str_pad(Math::baseConvert(Math::toString($n), 10, 2), $k, '0', STR_PAD_LEFT);
 
         for ($i = 0; $i < $k; ++$i) {
-            $j = ord($n1[$i]);
+            $j = $n1[$i];
             Point::cswap($r[0], $r[1], $j ^ 1);
             $r[0] = $this->add($r[0], $r[1]);
             $r[1] = $this->getDouble($r[1]);