Drop PHP 7.0 support

We need nullable types, but we cannot support them in both 7.0 and 8.4, so we're cutting 7.0 out.

.github/workflows/test.yml

@@ -5,12 +5,49 @@ on:
   pull_request:
 
 jobs:
-  test:
+  test-php7:
     runs-on: ${{ matrix.operating-system }}
     strategy:
       matrix:
         operating-system: ['ubuntu-20.04', 'ubuntu-22.04']
-        php-versions: ['7.0', '7.1', '7.2', '7.3', '7.4', '8.1', '8.2', '8.3', '8.4']
+        php-versions: ['7.1', '7.2', '7.3', '7.4']
+        phpunit-versions: ['latest']
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+          extensions: gmp
+          coverage: none
+
+      - name: Get composer cache directory
+        id: composer-cache
+        run: echo "::set-output name=dir::$(composer config cache-files-dir)"
+
+      - name: Cache dependencies
+        uses: actions/cache@v2
+        with:
+          path: ${{ steps.composer-cache.outputs.dir }}
+          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+          restore-keys: ${{ runner.os }}-composer-
+
+      - name: Install dependencies
+        run: composer install --prefer-dist
+
+      - name: Run tests
+        run: make phpunit-full-ci
+
+  test-php8:
+    runs-on: ${{ matrix.operating-system }}
+    strategy:
+      matrix:
+        operating-system: ['ubuntu-20.04', 'ubuntu-22.04']
+        php-versions: ['8.0', '8.1', '8.2', '8.3', '8.4']
         phpunit-versions: ['latest']
     steps:
     - name: Checkout

README.md

@@ -53,15 +53,10 @@ This package is released under the MIT license.
 
 ### Requirements
 
-* PHP 7.0+ or PHP 8.0+
+* PHP 7.1+ or PHP 8.0+
 * composer
 * ext-gmp
 
-Support for older PHP versions:
- * v0.4.x: php ^5.6|<7.2
- * v0.5.x: php ^7.0
- * v1.0.x: php ^7.0|^8.0
-
 ### Installation
 
 You can install this library via Composer :

composer.json

@@ -30,7 +30,7 @@
         }
     ],
     "require": {
-        "php": "^7.0||^8.0",
+        "php": "^7.1||^8.0",
         "ext-gmp": "*",
         "genkgo/php-asn1": "^2.0"
     },

phpunit.xml

@@ -14,6 +14,7 @@
       <directory suffix="Test.php">./tests/unit</directory>
     </testsuite>
   </testsuites>
+  <!--
   <logging>
     <log type="coverage-html" target="./tests/output/Coverage/"
       charset="UTF-8" yui="true" highlight="true" />
@@ -25,4 +26,5 @@
       <directory suffix=".php">src/</directory>
     </whitelist>
   </filter>
+  -->
 </phpunit>

src/Math/ConstantTimeMath.php

@@ -122,6 +122,7 @@ public function binaryGcd(GMP $X, GMP $Y): array
         $d = \gmp_init(1, 10);
 
         do {
+            // Iterate over U
             for ($bits = $this->trailingZeroes($u); $bits > 0; --$bits) {
                 $u = $this->rightShift($u, 1);
                 $swap = (~$this->lsb($a) & ~$this->lsb($b)) & 1;
@@ -133,6 +134,7 @@ public function binaryGcd(GMP $X, GMP $Y): array
                 $b = $this->rightShift($b, 1);
             }
 
+            // Iterate over V
             for ($bits = $this->trailingZeroes($v); $bits > 0; --$bits) {
                 $v = $this->rightShift($v, 1);
                 $swap = (~$this->lsb($c) & ~$this->lsb($d)) & 1;

src/Math/MathAdapterFactory.php

@@ -5,14 +5,14 @@
 class MathAdapterFactory
 {
     /**
-     * @var GmpMathInterface
+     * @var >GmpMathInterface
      */
     private static $forcedAdapter = null;
 
     /**
-     * @param GmpMathInterface $adapter
+     * @param ?GmpMathInterface $adapter
      */
-    public static function forceAdapter(GmpMathInterface $adapter = null)
+    public static function forceAdapter(?GmpMathInterface $adapter = null)
     {
         self::$forcedAdapter = $adapter;
     }

src/Math/NumberTheory.php

@@ -30,6 +30,7 @@
  * @author Matyas Danter
  */
 
+use GMP;
 use Mdanter\Ecc\Exception\NumberTheoryException;
 use Mdanter\Ecc\Exception\SquareRootException;
 
@@ -44,6 +45,21 @@ class NumberTheory
      */
     private $adapter;
 
+    /**
+     * @var GMP|resource
+     */
+    private $zero;
+
+    /**
+     * @var GMP|resource
+     */
+    private $one;
+
+    /**
+     * @var GMP|resource
+     */
+    private $two;
+
     /**
      * @param GmpMathInterface $adapter
      */
@@ -56,17 +72,17 @@ public function __construct(GmpMathInterface $adapter)
     }
 
     /**
-     * @param \GMP[] $poly
-     * @param \GMP[] $polymod
-     * @param \GMP $p
-     * @return \GMP[]
+     * @param GMP[] $poly
+     * @param GMP[] $polymod
+     * @param GMP $p
+     * @return GMP[]
      */
-    public function polynomialReduceMod(array $poly, array $polymod, \GMP $p): array
+    public function polynomialReduceMod(array $poly, array $polymod, GMP $p): array
     {
         $adapter = $this->adapter;
 
         // Only enter if last value is set, implying count > 0
-        if ((($last = end($polymod)) instanceof \GMP) && $adapter->equals($last, $this->one)) {
+        if ((($last = end($polymod)) instanceof GMP) && $adapter->equals($last, $this->one)) {
             $count_polymod = count($polymod);
             while (count($poly) >= $count_polymod) {
                 if (!$adapter->equals(end($poly), $this->zero)) {
@@ -95,13 +111,13 @@ public function polynomialReduceMod(array $poly, array $polymod, \GMP $p): array
     }
 
     /**
-     * @param \GMP[] $m1
-     * @param \GMP[] $m2
-     * @param \GMP[] $polymod
-     * @param \GMP $p
-     * @return \GMP[]
+     * @param GMP[] $m1
+     * @param GMP[] $m2
+     * @param GMP[] $polymod
+     * @param GMP $p
+     * @return GMP[]
      */
-    public function polynomialMultiplyMod(array $m1, array $m2, array $polymod, \GMP $p): array
+    public function polynomialMultiplyMod(array $m1, array $m2, array $polymod, GMP $p): array
     {
         $prod = array();
         $cm1 = count($m1);
@@ -131,13 +147,13 @@ public function polynomialMultiplyMod(array $m1, array $m2, array $polymod, \GMP
     }
 
     /**
-     * @param \GMP[] $base
-     * @param \GMP $exponent
-     * @param \GMP[] $polymod
-     * @param \GMP $p
-     * @return \GMP[]
+     * @param GMP[] $base
+     * @param GMP $exponent
+     * @param GMP[] $polymod
+     * @param GMP $p
+     * @return GMP[]
      */
-    public function polynomialPowMod(array $base, \GMP $exponent, array $polymod, \GMP $p): array
+    public function polynomialPowMod(array $base, GMP $exponent, array $polymod, GMP $p): array
     {
         $adapter = $this->adapter;
 
@@ -171,11 +187,11 @@ public function polynomialPowMod(array $base, \GMP $exponent, array $polymod, \G
     }
 
     /**
-     * @param \GMP $a
-     * @param \GMP $p
-     * @return \GMP
+     * @param GMP $a
+     * @param GMP $p
+     * @return GMP
      */
-    public function squareRootModP(\GMP $a, \GMP $p): \GMP
+    public function squareRootModP(GMP $a, GMP $p): GMP
     {
         $math = $this->adapter;
         $four = gmp_init(4, 10);